Sample records for saline vehicle control

  1. Saline as a vehicle control does not alter ventilation in male CD-1 mice.

    PubMed

    Receno, Candace N; Glausen, Taylor G; DeRuisseau, Lara R

    2018-05-01

    Saline (0.9% NaCl) is used in clinical and research settings as a vehicle for intravenous drug administration. While saline is a standard control in mouse studies, there are reports of hyperchloremic metabolic acidosis in high doses. It remains unknown if metabolic acidosis occurs in mice and/or if compensatory increases in breathing frequency and tidal volume accompany saline administration. It was hypothesized that saline administration alters blood pH and the pattern of breathing in conscious CD-1 male mice exposed to air or hypoxia (10% O 2 , balanced N 2 ). Unrestrained barometric plethysmography was used to quantify breathing frequency (breaths/min; bpm), tidal volume (VT; mL/breath/10 g body weight (BW)), and minute ventilation (VE; mL/min/10 g BW) in two designs: (1) 11-week-old mice with no saline exposure (n = 11) compared to mice with 7 days of 0.9% saline administration (intraperitoneal, i.p.; 10 mL/kg body mass; n = 6). and (2) 17-week-old mice tested before (PRE) and after 1 day (POST1, n = 6) or 7 days (POST7, n = 5) of saline (i.p.; 10 mL/kg body mass). There were no differences when comparing frequency, VT, or VE between groups for either design with room air or hypoxia exposures. Hypoxia increased frequency, VT, and VE compared to room air. Moreover, conscious blood sampling showed no differences in pH, p a CO 2 , p aO2 , or HCO3- in mice without or with 7 days of saline. These findings reveal no differences in ventilation following 1 and/or 7 days of saline administration in mice. Therefore, the use of 0.9% saline as a control is supported for studies evaluating the control of breathing in mice. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  2. Salinity Trends in the Upper Colorado River Basin Upstream From the Grand Valley Salinity Control Unit, Colorado, 1986-2003

    USGS Publications Warehouse

    Leib, Kenneth J.; Bauch, Nancy J.

    2008-01-01

    In 1974, the Colorado River Basin Salinity Control Act was passed into law. This law was enacted to address concerns regarding the salinity content of the Colorado River. The law authorized various construction projects in selected areas or 'units' of the Colorado River Basin intended to reduce the salinity load in the Colorado River. One such area was the Grand Valley Salinity Control Unit in western Colorado. The U. S. Geological Survey has done extensive studies and research in the Grand Valley Salinity Control Unit that provide information to aid the U.S. Bureau of Reclamation and the Natural Resources Conservation Service in determining where salinity-control work may provide the best results, and to what extent salinity-control work was effective in reducing salinity concentrations and loads in the Colorado River. Previous studies have indicated that salinity concentrations and loads have been decreasing downstream from the Grand Valley Salinity Control Unit, and that the decreases are likely the result of salinity control work in these areas. Several of these reports; however, also document decreasing salinity loads upstream from the Grand Valley Salinity Control Unit. This finding was important because only a small amount of salinity-control work was being done in areas upstream from the Grand Valley Salinity Control Unit at the time the findings were reported (late 1990?s). As a result of those previous findings, the U.S. Bureau of Reclamation entered into a cooperative agreement with the U.S. Geological Survey to investigate salinity trends in selected areas bracketing the Grand Valley Salinity Control Unit and regions upstream from the Grand Valley Salinity Control Unit. The results of the study indicate that salinity loads were decreasing upstream from the Grand Valley Salinity Control Unit from 1986 through 2003, but the rates of decrease have slowed during the last 10 years. The average rate of decrease in salinity load upstream from the Grand Valley

  3. 75 FR 25877 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-10

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Colorado River Basin Salinity Control Advisory... River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control [[Page 25878

  4. Battery control system for hybrid vehicle and method for controlling a hybrid vehicle battery

    DOEpatents

    Bockelmann, Thomas R [Battle Creek, MI; Beaty, Kevin D [Kalamazoo, MI; Zou, Zhanijang [Battle Creek, MI; Kang, Xiaosong [Battle Creek, MI

    2009-07-21

    A battery control system for controlling a state of charge of a hybrid vehicle battery includes a detecting arrangement for determining a vehicle operating state or an intended vehicle operating state and a controller for setting a target state of charge level of the battery based on the vehicle operating state or the intended vehicle operating state. The controller is operable to set a target state of charge level at a first level during a mobile vehicle operating state and at a second level during a stationary vehicle operating state or in anticipation of the vehicle operating in the stationary vehicle operating state. The invention further includes a method for controlling a state of charge of a hybrid vehicle battery.

  5. 76 FR 24515 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-02

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Colorado River Basin Salinity Control Advisory... Basin Salinity Control Advisory Council (Council) will meet as detailed below. The meeting of the... INFORMATION: The Colorado River Basin Salinity Control Advisory Council was established by the Colorado River...

  6. 78 FR 70574 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ...] Colorado River Basin Salinity Control Advisory Council AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of public meeting. SUMMARY: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L.93-320) (Act) to...

  7. 77 FR 61784 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-11

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Colorado River Basin Salinity Control Advisory... River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L. 93-320) (Act) to receive reports and advise Federal agencies on...

  8. 77 FR 23508 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Colorado River Basin Salinity Control Advisory... River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L. 93-320) (Act) to receive reports and advise Federal agencies on...

  9. 78 FR 23784 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-22

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Colorado River Basin Salinity Control Advisory... River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Public Law 93-320) (Act) to receive reports and advise Federal agencies on...

  10. 75 FR 66389 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-28

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Colorado River Basin Salinity Control Advisory... River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L. 93-320) (Act) to receive reports and advise Federal agencies on...

  11. 75 FR 27360 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-14

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Colorado River Basin Salinity Control Advisory... River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L. 93-320) (Act) to receive reports and advise Federal agencies on...

  12. 76 FR 61382 - Colorado River Basin Salinity Control Advisory Council

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-04

    ... DEPARTMENT OF THE INTERIOR Bureau of Reclamation Colorado River Basin Salinity Control Advisory...: The Colorado River Basin Salinity Control Advisory Council (Council) was established by the Colorado River Basin Salinity Control Act of 1974 (Pub. L. 93-320) (Act) to receive reports and advise Federal...

  13. Remote control for motor vehicle

    NASA Technical Reports Server (NTRS)

    Johnson, Dale R. (Inventor); Ciciora, John A. (Inventor)

    1984-01-01

    A remote controller is disclosed for controlling the throttle, brake and steering mechanism of a conventional motor vehicle, with the remote controller being particularly advantageous for use by severely handicapped individuals. The controller includes a remote manipulator which controls a plurality of actuators through interfacing electronics. The remote manipulator is a two-axis joystick which controls a pair of linear actuators and a rotary actuator, with the actuators being powered by electric motors to effect throttle, brake and steering control of a motor vehicle adapted to include the controller. The controller enables the driver to control the adapted vehicle from anywhere in the vehicle with one hand with minimal control force and range of motion. In addition, even though a conventional vehicle is adapted for use with the remote controller, the vehicle may still be operated in the normal manner.

  14. Battery control system for hybrid vehicle and method for controlling a hybrid vehicle battery

    DOEpatents

    Bockelmann, Thomas R [Battle Creek, MI; Hope, Mark E [Marshall, MI; Zou, Zhanjiang [Battle Creek, MI; Kang, Xiaosong [Battle Creek, MI

    2009-02-10

    A battery control system for hybrid vehicle includes a hybrid powertrain battery, a vehicle accessory battery, and a prime mover driven generator adapted to charge the vehicle accessory battery. A detecting arrangement is configured to monitor the vehicle accessory battery's state of charge. A controller is configured to activate the prime mover to drive the generator and recharge the vehicle accessory battery in response to the vehicle accessory battery's state of charge falling below a first predetermined level, or transfer electrical power from the hybrid powertrain battery to the vehicle accessory battery in response to the vehicle accessory battery's state of charge falling below a second predetermined level. The invention further includes a method for controlling a hybrid vehicle powertrain system.

  15. Vehicle influence on permeation through intact and compromised skin.

    PubMed

    Gujjar, Meera; Banga, Ajay K

    2014-09-10

    The purpose of this study was to compare the transdermal permeation of a model compound, diclofenac diethylamine, from a hydrophilic and lipophilic vehicle across in vitro models simulating compromised skin. Mineral oil served as a lipophilic vehicle while 10mM phosphate buffered saline served as a hydrophilic vehicle. Compromised skin was simulated by tape stripping, delipidization, or microneedle application and compared with intact skin as a control. Transepidermal water loss was measured to assess barrier function. Skin compromised with tape stripping and delipidization significantly (p<0.05) increased permeation of diclofenac diethylamine compared to intact and microneedle treated skin with phosphate buffered saline vehicle. A similar trend in permeation was observed with mineral oil as the vehicle. For both vehicles, permeation across skin increased in the same order and correlated with degree of barrier impairment as indicated by transepidermal water loss values: intactvehicles found the same trend, with hydrophilic vehicle having greater delivery. In conclusion, phosphate buffered saline vehicle resulted in higher permeation into and across skin compared to mineral oil vehicle for all simulated models of compromised skin. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Vehicle following controller design for autonomous intelligent vehicles

    NASA Technical Reports Server (NTRS)

    Chien, C. C.; Lai, M. C.; Mayr, R.

    1994-01-01

    A new vehicle following controller is proposed for autonomous intelligent vehicles. The proposed vehicle following controller not only provides smooth transient maneuvers for unavoidable nonzero initial conditions but also guarantees the asymptotic platoon stability without the availability of feedforward information. Furthermore, the achieved asymptotic platoon stability is shown to be robust to sensor delays and an upper bound for the allowable sensor delays is also provided in this paper.

  17. Dynamics and Control of Vehicles

    Science.gov Websites

    Contacts Researchers Thrust Area 1: Dynamics and Control of Vehicles Thrust Area Leader: Dr. Tulga Ersal economy, mobility, and safety of modern vehicles heavily rely on the numerous control systems that fulfill storage in electrified powertrains. All these vehicle control systems rely in turn on a solid

  18. Salinity controls on plant transpiration and soil water balance

    NASA Astrophysics Data System (ADS)

    Perri, S.; Molini, A.; Suweis, S. S.; Viola, F.; Entekhabi, D.

    2017-12-01

    Soil salinization and aridification represent a major threat for the food security and sustainable development of drylands. The two problems are deeply connected, and their interplay is expected to be further enhanced by climate change and projected population growth. Salt-affected land is currently estimated to cover around 1.1 Gha, and is particularly widespread in semi-arid to hyper-arid climates. Over 900 Mha of these saline/sodic soils are potentially available for crop or biomass production. Salt-tolerant plants have been recently proposed as valid solution to exploit or even remediate salinized soils. However the effects of salinity on evapotranspiration, soil water balance and the long-term salt mass balance in the soil, are still largely unexplored. In this contribution we analyze the feedback of evapotranspiration on soil salinization, with particular emphasis on the role of vegetation and plant salt-tolerance. The goal is to introduce a simple modeling framework able to shed some light on how (a) soil salinity controls plant transpiration, and (b) salinization itself is favored/impeded by different vegetation feedback. We introduce at this goal a spatially lumped stochastic model of soil moisture and salt mass dynamics averaged over the active soil depth, and accounting for the effect of salinity on evapotranspiration. Here, the limiting effect of salinity on ET is modeled through a simple plant response function depending on both salt concentration in the soil and plant salt-tolerance. The coupled soil moisture and salt mass balance is hence used to obtain the conditional steady-state probability density function (pdf) of soil moisture for given salt tolerance and salinization level, Our results show that salinity imposes a limit in the soil water balance and this limit depends on plant salt-tolerance mainly through the control of the leaching occurrence (tolerant plants exploit water more efficiently than the sensitive ones). We also analyzed the

  19. Software control architecture for autonomous vehicles

    NASA Astrophysics Data System (ADS)

    Nelson, Michael L.; DeAnda, Juan R.; Fox, Richard K.; Meng, Xiannong

    1999-07-01

    The Strategic-Tactical-Execution Software Control Architecture (STESCA) is a tri-level approach to controlling autonomous vehicles. Using an object-oriented approach, STESCA has been developed as a generalization of the Rational Behavior Model (RBM). STESCA was initially implemented for the Phoenix Autonomous Underwater Vehicle (Naval Postgraduate School -- Monterey, CA), and is currently being implemented for the Pioneer AT land-based wheeled vehicle. The goals of STESCA are twofold. First is to create a generic framework to simplify the process of creating a software control architecture for autonomous vehicles of any type. Second is to allow for mission specification system by 'anyone' with minimal training to control the overall vehicle functionality. This paper describes the prototype implementation of STESCA for the Pioneer AT.

  20. The automation of remote vehicle control. [in Mars roving vehicles

    NASA Technical Reports Server (NTRS)

    Paine, G.

    1977-01-01

    The automation of remote vehicles is becoming necessary to overcome the requirement of having man present as a controller. By removing man, remote vehicles can be operated in areas where the environment is too hostile for man, his reaction times are too slow, time delays are too long, and where his presence is too costly, or where system performance can be improved. This paper addresses the development of automated remote vehicle control for nonspace and space tasks from warehouse vehicles to proposed Mars rovers. The state-of-the-art and the availability of new technology for implementing automated control are reviewed and the major problem areas are outlined. The control strategies are divided into those where the path is planned in advance or constrained, or where the system is a teleoperator, or where automation or robotics have been introduced.

  1. Decentralized Control of Autonomous Vehicles

    DTIC Science & Technology

    2003-01-01

    Autonomous Vehicles by John S. Baras, Xiaobo Tan, Pedram Hovareshti CSHCN TR 2003-8 (ISR TR 2003-14) Report Documentation Page Form ApprovedOMB No. 0704...AND SUBTITLE Decentralized Control of Autonomous Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Decentralized Control of Autonomous Vehicles ∗ John S. Baras, Xiaobo Tan, and Pedram

  2. Launch Vehicle Control Center Architectures

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Epps, Amy; Woodruff, Van; Vachon, Michael Jacob; Monreal, Julio; Levesque, Marl; Williams, Randall; Mclaughlin, Tom

    2014-01-01

    Launch vehicles within the international community vary greatly in their configuration and processing. Each launch site has a unique processing flow based on the specific launch vehicle configuration. Launch and flight operations are managed through a set of control centers associated with each launch site. Each launch site has a control center for launch operations; however flight operations support varies from being co-located with the launch site to being shared with the space vehicle control center. There is also a nuance of some having an engineering support center which may be co-located with either the launch or flight control center, or in a separate geographical location altogether. A survey of control center architectures is presented for various launch vehicles including the NASA Space Launch System (SLS), United Launch Alliance (ULA) Atlas V and Delta IV, and the European Space Agency (ESA) Ariane 5. Each of these control center architectures shares some similarities in basic structure while differences in functional distribution also exist. The driving functions which lead to these factors are considered and a model of control center architectures is proposed which supports these commonalities and variations.

  3. Using the lead vehicle as preview sensor in convoy vehicle active suspension control

    NASA Astrophysics Data System (ADS)

    Rahman, Mustafizur; Rideout, Geoff

    2012-12-01

    Both ride quality and roadholding of actively suspended vehicles can be improved by sensing the road ahead of the vehicle and using this information in a preview controller. Previous applications have used look-ahead sensors mounted on the front bumper to measure terrain beneath. Such sensors are vulnerable, potentially confused by water, snow, or other soft obstacles and offer a fixed preview time. For convoy vehicle applications, this paper proposes using the overall response of the preceding vehicle(s) to generate preview controller information for follower vehicles. A robust observer is used to estimate the states of a quarter-car vehicle model, from which road profile is estimated and passed on to the follower vehicle(s) to generate a preview function. The preview-active suspension, implemented in discrete time using a shift register approach to improve simulation time, reduces sprung mass acceleration and dynamic tyre deflection peaks by more than 50% and 40%, respectively. Terrain can change from one vehicle to the next if a loose obstacle is dislodged, or if the vehicle paths are sufficiently different so that one vehicle misses a discrete road event. The resulting spurious preview information can give suspension performance worse than that of a passive or conventional active system. In this paper, each vehicle can effectively estimate the road profile based on its own state trajectory. By comparing its own road estimate with the preview information, preview errors can be detected and suspension control quickly switched from preview to conventional active control to preserve performance improvements compared to passive suspensions.

  4. Vehicle yaw stability control via H∞ gain scheduling

    NASA Astrophysics Data System (ADS)

    Zhang, Jinhua; Sun, Weichao; Feng, Zhiguang

    2018-06-01

    Yaw stability control (YSC) is rather significant in a vehicle lateral motion, since it can considerably reduce casualties caused by vehicle instability. Nevertheless with the vehicle running, the parameters, such as vehicle mass and moment of inertial, can be perturbed because of variation of capacity, loadage and consumption of fuel, hence some of nominal controllers cannot always work satisfactorily. To overcome the aforementioned deficiency, a gain scheduled H∞ YSC controller is developed in this paper, taking the vehicle mass and moment of inertial as the scheduled variables, now that the gain scheduled H∞ controller can guarantee both the robustness against parameter perturbation and the adjustability of tracking accuracy. Then the constructed controller is verified via numerical simulation and MATLAB-CarSim coalition simulation. The simulation results indicate that the designed controller can indeed improve the vehicle handing performance under circumstance of lateral stability.

  5. Electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, S.R.

    1995-09-12

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydraulic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control. 10 figs.

  6. Electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, Susan R.

    1995-01-01

    An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

  7. 49 CFR 176.89 - Control of transport vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Control of transport vehicles. 176.89 Section 176... Special Requirements for Transport Vehicles Loaded With Hazardous Materials and Transported on Board Ferry Vessels § 176.89 Control of transport vehicles. (a) A transport vehicle containing hazardous materials may...

  8. 49 CFR 176.89 - Control of transport vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Control of transport vehicles. 176.89 Section 176... Special Requirements for Transport Vehicles Loaded With Hazardous Materials and Transported on Board Ferry Vessels § 176.89 Control of transport vehicles. (a) A transport vehicle containing hazardous materials may...

  9. 49 CFR 176.89 - Control of transport vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Control of transport vehicles. 176.89 Section 176... Special Requirements for Transport Vehicles Loaded With Hazardous Materials and Transported on Board Ferry Vessels § 176.89 Control of transport vehicles. (a) A transport vehicle containing hazardous materials may...

  10. 49 CFR 176.89 - Control of transport vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Control of transport vehicles. 176.89 Section 176... Special Requirements for Transport Vehicles Loaded With Hazardous Materials and Transported on Board Ferry Vessels § 176.89 Control of transport vehicles. (a) A transport vehicle containing hazardous materials may...

  11. 49 CFR 176.89 - Control of transport vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Control of transport vehicles. 176.89 Section 176... Special Requirements for Transport Vehicles Loaded With Hazardous Materials and Transported on Board Ferry Vessels § 176.89 Control of transport vehicles. (a) A transport vehicle containing hazardous materials may...

  12. Design of Launch Vehicle Flight Control Systems Using Ascent Vehicle Stability Analysis Tool

    NASA Technical Reports Server (NTRS)

    Jang, Jiann-Woei; Alaniz, Abran; Hall, Robert; Bedossian, Nazareth; Hall, Charles; Jackson, Mark

    2011-01-01

    A launch vehicle represents a complicated flex-body structural environment for flight control system design. The Ascent-vehicle Stability Analysis Tool (ASAT) is developed to address the complicity in design and analysis of a launch vehicle. The design objective for the flight control system of a launch vehicle is to best follow guidance commands while robustly maintaining system stability. A constrained optimization approach takes the advantage of modern computational control techniques to simultaneously design multiple control systems in compliance with required design specs. "Tower Clearance" and "Load Relief" designs have been achieved for liftoff and max dynamic pressure flight regions, respectively, in the presence of large wind disturbances. The robustness of the flight control system designs has been verified in the frequency domain Monte Carlo analysis using ASAT.

  13. Control system and method for a hybrid electric vehicle

    DOEpatents

    Phillips, Anthony Mark; Blankenship, John Richard; Bailey, Kathleen Ellen; Jankovic, Miroslava

    2001-01-01

    A vehicle system controller (20) is presented for a LSR parallel hybrid electric vehicle having an engine (10), a motor (12), wheels (14), a transmission (16) and a battery (18). The vehicle system controller (20) has a state machine having a plurality of predefined states (22-32) that represent operating modes for the vehicle. A set of rules is defined for controlling the transition between any two states in the state machine. The states (22-32) are prioritized according to driver demands, energy management concerns and system fault occurrences. The vehicle system controller (20) controls the transitions from a lower priority state to a higher priority state based on the set of rules. In addition, the vehicle system controller (20) will control a transition to a lower state from a higher state when the conditions no longer warrant staying in the current state. A unique set of output commands is defined for each state for the purpose of controlling lower level subsystem controllers. These commands serve to achieve the desire vehicle functionality within each state and insure smooth transitions between states.

  14. Vehicle Controller

    NASA Technical Reports Server (NTRS)

    1985-01-01

    UNISTICK is an airplane-like joystick being developed by Johnson Engineering under NASA and VA sponsorship. It allows a driver to control a vehicle with one hand, and is based upon technology developed for the Apollo Lunar Landings of the 1970's. It allows severely handicapped drivers to operate an automobile or van easily. The system is expected to be in production by March 1986.

  15. Automotive Control Systems: For Engine, Driveline, and Vehicle

    NASA Astrophysics Data System (ADS)

    Kiencke, Uwe; Nielsen, Lars

    Advances in automotive control systems continue to enhance safety and comfort and to reduce fuel consumption and emissions. Reflecting the trend to optimization through integrative approaches for engine, driveline, and vehicle control, this valuable book enables control engineers to understand engine and vehicle models necessary for controller design, and also introduces mechanical engineers to vehicle-specific signal processing and automatic control. The emphasis on measurement, comparisons between performance and modeling, and realistic examples derive from the authors' unique industrial experience

  16. Ground vehicle control at NIST: From teleoperation to autonomy

    NASA Technical Reports Server (NTRS)

    Murphy, Karl N.; Juberts, Maris; Legowik, Steven A.; Nashman, Marilyn; Schneiderman, Henry; Scott, Harry A.; Szabo, Sandor

    1994-01-01

    NIST is applying their Real-time Control System (RCS) methodology for control of ground vehicles for both the U.S. Army Researh Lab, as part of the DOD's Unmanned Ground Vehicles program, and for the Department of Transportation's Intelligent Vehicle/Highway Systems (IVHS) program. The actuated vehicle, a military HMMWV, has motors for steering, brake, throttle, etc. and sensors for the dashboard gauges. For military operations, the vehicle has two modes of operation: a teleoperation mode--where an operator remotely controls the vehicle over an RF communications network; and a semi-autonomous mode called retro-traverse--where the control system uses an inertial navigation system to steer the vehicle along a prerecorded path. For the IVHS work, intelligent vision processing elements replace the human teleoperator to achieve autonomous, visually guided road following.

  17. Intelligent vehicle safety control strategy in various driving situations

    NASA Astrophysics Data System (ADS)

    Moon, Seungwuk; Cho, Wanki; Yi, Kyongsu

    2010-12-01

    This paper describes a safety control strategy for intelligent vehicles with the objective of optimally coordinating the throttle, brake, and active front steering actuator inputs to obtain both lateral stability and longitudinal safety. The control system consists of a supervisor, control algorithms, and a coordinator. From the measurement and estimation signals, the supervisor determines the active control modes among normal driving, longitudinal safety, lateral stability, and integrated safety control mode. The control algorithms consist of longitudinal and lateral stability controllers. The longitudinal controller is designed to improve the driver's comfort during normal, safe-driving situations, and to avoid rear-end collision in vehicle-following situations. The lateral stability controller is designed to obtain the required manoeuvrability and to limit the vehicle body's side-slip angle. To obtain both longitudinal safety and lateral stability control in various driving situations, the coordinator optimally determines the throttle, brake, and active front steering inputs based on the current status of the subject vehicle. Closed-loop simulations with the driver-vehicle-controller system are conducted to investigate the performance of the proposed control strategy. From these simulation results, it is shown that the proposed control algorithm assists the driver in combined severe braking/large steering manoeuvring so that the driver can maintain good manoeuvrability and prevent the vehicle from crashing in vehicle-following situations.

  18. Comparison of three control methods for an autonomous vehicle

    NASA Astrophysics Data System (ADS)

    Deshpande, Anup; Mathur, Kovid; Hall, Ernest

    2010-01-01

    The desirability and challenge of developing a completely autonomous vehicle and the rising need for more efficient use of energy by automobiles motivate this research- a study for an optimum solution to computer control of energy efficient vehicles. The purpose of this paper is to compare three control methods - mechanical, hydraulic and electric that have been used to convert an experimental all terrain vehicle to drive by wire which would eventually act as a test bed for conducting research on various technologies for autonomous operation. Computer control of basic operations in a vehicle namely steering, braking and speed control have been implemented and will be described in this paper. The output from a 3 axis motion controller is used for this purpose. The motion controller is interfaced with a software program using WSDK (Windows Servo Design Kit) as an intermediate tuning layer for tuning and parameter settings in autonomous operation. The software program is developed in C++. The voltage signal sent to the motion controller can be varied through the control program for desired results in controlling the steering motor, activating the hydraulic brakes and varying the vehicle's speed. The vehicle has been tested for its basic functionality which includes testing of street legal operations and also a 1000 mile test while running in a hybrid mode. The vehicle has also been tested for control when it is interfaced with devices such as a keyboard, joystick and sensors under full autonomous operation. The vehicle is currently being tested in various safety studies and is being used as a test bed for experiments in control courses and research studies. The significance of this research is in providing a greater understanding of conventional driving controls and the possibility of improving automobile safety by removing human error in control of a motor vehicle.

  19. Fractional Control of An Active Four-wheel-steering Vehicle

    NASA Astrophysics Data System (ADS)

    Wang, Tianting; Tong, Jun; Chen, Ning; Tian, Jie

    2018-03-01

    A four-wheel-steering (4WS) vehicle model and reference model with a drop filter are constructed. The decoupling of 4WS vehicle model is carried out. And a fractional PIλDμ controller is introduced into the decoupling strategy to reduce the effects of the uncertainty of the vehicle parameters as well as the unmodelled dynamics on the system performance. Based on optimization techniques, the design of fractional controller are obtained to ensure the robustness of 4WS vehicle during the special range of frequencies through proper choice of the constraints. In order to compare with fractional robust controller, an optimal controller for the same vehicle is also designed. The simulations of the two control systems are carried out and it reveals that the decoupling and fractional robust controller is able to make vehicle model trace the reference model very well with better robustness.

  20. Supercavitating Vehicle Control

    DTIC Science & Technology

    2008-10-10

    herein as winglets , are supported by a strut attached to the vehicle. The angle of attack of each winglet is controlled by a winglet actuator. The... winglet assembly may be extended into or retracted from the water by means of a spring-loaded actuated mount, which pivots the strut supporting the... winglet . When fully retracted, the winglet assembly is contained completely within the cavity. [0014] The segmented ring wing is controlled by one or more

  1. Dynamics and Control of Flexible Space Vehicles

    NASA Technical Reports Server (NTRS)

    Likins, P. W.

    1970-01-01

    The purpose of this report is twofold: (1) to survey the established analytic procedures for the simulation of controlled flexible space vehicles, and (2) to develop in detail methods that employ a combination of discrete and distributed ("modal") coordinates, i.e., the hybrid-coordinate methods. Analytic procedures are described in three categories: (1) discrete-coordinate methods, (2) hybrid-coordinate methods, and (3) vehicle normal-coordinate methods. Each of these approaches is described and analyzed for its advantages and disadvantages, and each is found to have an area of applicability. The hybrid-coordinate method combines the efficiency of the vehicle normal-coordinate method with the versatility of the discrete-coordinate method, and appears to have the widest range of practical application. The results in this report have practical utility in two areas: (1) complex digital computer simulation of flexible space vehicles of arbitrary configuration subject to realistic control laws, and (2) preliminary control system design based on transfer functions for linearized models of dynamics and control laws.

  2. Advanced control architecture for autonomous vehicles

    NASA Astrophysics Data System (ADS)

    Maurer, Markus; Dickmanns, Ernst D.

    1997-06-01

    An advanced control architecture for autonomous vehicles is presented. The hierarchical architecture consists of four levels: a vehicle level, a control level, a rule-based level and a knowledge-based level. A special focus is on forms of internal representation, which have to be chosen adequately for each level. The control scheme is applied to VaMP, a Mercedes passenger car which autonomously performs missions on German freeways. VaMP perceives the environment with its sense of vision and conventional sensors. It controls its actuators for locomotion and attention focusing. Modules for perception, cognition and action are discussed.

  3. Automated mixed traffic vehicle control and scheduling study

    NASA Technical Reports Server (NTRS)

    Peng, T. K. C.; Chon, K.

    1976-01-01

    The operation and the expected performance of a proposed automatic guideway transit system which uses low speed automated mixed traffic vehicles (AMTVs) were analyzed. Vehicle scheduling and headway control policies were evaluated with a transit system simulation model. The effect of mixed traffic interference on the average vehicle speed was examined with a vehicle pedestrian interface model. Control parameters regulating vehicle speed were evaluated for safe stopping and passenger comfort. Some preliminary data on the cost and operation of an experimental AMTV system are included. These data were the result of a separate task conducted at JPL, and were included as background information.

  4. Longitudinal Control for Mengshi Autonomous Vehicle via Cloud Model

    NASA Astrophysics Data System (ADS)

    Gao, H. B.; Zhang, X. Y.; Li, D. Y.; Liu, Y. C.

    2018-03-01

    Dynamic robustness and stability control is a requirement for self-driving of autonomous vehicle. Longitudinal control method of autonomous is a key technique which has drawn the attention of industry and academe. In this paper, we present a longitudinal control algorithm based on cloud model for Mengshi autonomous vehicle to ensure the dynamic stability and tracking performance of Mengshi autonomous vehicle. An experiments is applied to test the implementation of the longitudinal control algorithm. Empirical results show that if the longitudinal control algorithm based Gauss cloud model are applied to calculate the acceleration, and the vehicles drive at different speeds, a stable longitudinal control effect is achieved.

  5. Guidance and control for unmanned ground vehicles

    NASA Astrophysics Data System (ADS)

    Bateman, Peter J.

    1994-06-01

    Techniques for the guidance, control, and navigation of unmanned ground vehicles are described in terms of the communication bandwidth requirements for driving and control of a vehicle remote from the human operator. Modes of operation are conveniently classified as conventional teleoperation, supervisory control, and fully autonomous control. The fundamental problem of maintaining a robust non-line-of-sight communications link between the human controller and the remote vehicle is discussed, as this provides the impetus for greater autonomy in the control system and the greatest scope for innovation. While supervisory control still requires the man to be providing the primary navigational intelligence, fully autonomous operation requires that mission navigation is provided solely by on-board machine intelligence. Methods directed at achieving this performance are described using various active and passive sensing of the terrain for route navigation and obstacle detection. Emphasis is given to TV imagery and signal processing techniques for image understanding. Reference is made to the limitations of current microprocessor technology and suitable computer architectures. Some of the more recent control techniques involve the use of neural networks, fuzzy logic, and data fusion and these are discussed in the context of road following and cross country navigation. Examples of autonomous vehicle testbeds operated at various laboratories around the world are given.

  6. Automatic Control of Personal Rapid Transit Vehicles

    NASA Technical Reports Server (NTRS)

    Smith, P. D.

    1972-01-01

    The requirements for automatic longitudinal control of a string of closely packed personal vehicles are outlined. Optimal control theory is used to design feedback controllers for strings of vehicles. An important modification of the usual optimal control scheme is the inclusion of jerk in the cost functional. While the inclusion of the jerk term was considered, the effect of its inclusion was not sufficiently studied. Adding the jerk term will increase passenger comfort.

  7. A nonlinear strategy for sensor based vehicle path control

    NASA Technical Reports Server (NTRS)

    Mayr, R.

    1994-01-01

    A method of transverse control which makes use of nonlinear formulations is presented. The strategy is utilized to stabilize a vehicle. The vehicle is autonomously guided and takes its control inputs from an optical sensing system. Additionally, the velocity of the vehicle is dictated by a longitudinal controller, which is also discussed.

  8. Vehicle Dynamics Control of In-wheel Electric Motor Drive Vehicles Based on Averaging of Tire Force Usage

    NASA Astrophysics Data System (ADS)

    Masaki, Nobuo; Iwano, Haruo; Kamada, Takayoshi; Nagai, Masao

    For in-wheel electric motor drive vehicles, a new vehicle dynamics control which is based on the tire force usage rate is proposed. The new controller adopts non-linear optimal control could manage the interference between direct yaw-moment control and the tire force usage rate. The new control is considered total longitudinal and transverse tire force. Therefore the controller can prevent tire force saturation near tire force limit during cornering. Simulations and test runs by the custom made four wheel drive in-wheel motor electric vehicle show that higher driving stability performance compared to the performance of the same vehicle without control.

  9. Robust, Practical Adaptive Control for Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Orr, Jeb. S.; VanZwieten, Tannen S.

    2012-01-01

    A modern mechanization of a classical adaptive control concept is presented with an application to launch vehicle attitude control systems. Due to a rigorous flight certification environment, many adaptive control concepts are infeasible when applied to high-risk aerospace systems; methods of stability analysis are either intractable for high complexity models or cannot be reconciled in light of classical requirements. Furthermore, many adaptive techniques appearing in the literature are not suitable for application to conditionally stable systems with complex flexible-body dynamics, as is often the case with launch vehicles. The present technique is a multiplicative forward loop gain adaptive law similar to that used for the NASA X-15 flight research vehicle. In digital implementation with several novel features, it is well-suited to application on aerodynamically unstable launch vehicles with thrust vector control via augmentation of the baseline attitude/attitude-rate feedback control scheme. The approach is compatible with standard design features of autopilots for launch vehicles, including phase stabilization of lateral bending and slosh via linear filters. In addition, the method of assessing flight control stability via classical gain and phase margins is not affected under reasonable assumptions. The algorithm s ability to recover from certain unstable operating regimes can in fact be understood in terms of frequency-domain criteria. Finally, simulation results are presented that confirm the ability of the algorithm to improve performance and robustness in realistic failure scenarios.

  10. Circulation Control in NASA's Vehicle Systems

    NASA Technical Reports Server (NTRS)

    Rich, Paul; McKinley, Bob; Jones, Greg

    2005-01-01

    Specific to the application of any technology to a vehicle, such as circulation control, it is important to understand the process that NASA is using to set its direction in research and development. To see how circulation control fits into any given NASA program requires the reader to understand NASA's Vehicle Systems (VS) Program. The VS Program recently celebrated its first year of existence with an annual review - an opportunity to look back on accomplishments, solicit feedback, expand national advocacy and support for the program, and recognize key contributions. Since its formation last year, Vehicle Systems has coordinated seven existing entities in a streamlined aeronautics research effort. It invests in vehicle technologies to protect the environment, make air travel more accessible and affordable for Americans, enable exploration through new aerospace missions, and augment national security. This past year has seen a series of valuable partnerships with industry, academia, and government agencies to make crucial aeronautics advances and assure America s future in flight.

  11. Adaptive Control Allocation for Fault Tolerant Overactuated Autonomous Vehicles

    DTIC Science & Technology

    2007-11-01

    Tolerant Overactuated Autonomous Vehicles Casavola, A.; Garone, E. (2007) Adaptive Control Allocation for Fault Tolerant Overactuated Autonomous ...Adaptive Control Allocation for Fault Tolerant Overactuated Autonomous Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Tolerant Overactuated Autonomous Vehicles 3.2 - 2 RTO-MP-AVT-145 UNCLASSIFIED/UNLIMITED Control allocation problem (CAP) - Given a virtual input v(t

  12. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, Susan R.

    1994-01-01

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

  13. Fuzzy logic electric vehicle regenerative antiskid braking and traction control system

    DOEpatents

    Cikanek, S.R.

    1994-10-25

    An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control. 123 figs.

  14. Tasking and control of a squad of robotic vehicles

    NASA Astrophysics Data System (ADS)

    Lewis, Christopher L.; Feddema, John T.; Klarer, Paul

    2001-09-01

    Sandia National Laboratories have developed a squad of robotic vehicles as a test-bed for investigating cooperative control strategies. The squad consists of eight RATLER vehicles and a command station. The RATLERs are medium-sized all-electric vehicles containing a PC104 stack for computation, control, and sensing. Three separate RF channels are used for communications; one for video, one for command and control, and one for differential GPS corrections. Using DGPS and IR proximity sensors, the vehicles are capable of autonomously traversing fairly rough terrain. The control station is a PC running Windows NT. A GUI has been developed that allows a single operator to task and monitor all eight vehicles. To date, the following mission capabilities have been demonstrated: 1. Way-Point Navigation, 2. Formation Following, 3. Perimeter Surveillance, 4. Surround and Diversion, and 5. DGPS Leap Frog. This paper describes the system and briefly outlines each mission capability. The DGPS Leap Frog capability is discussed in more detail. This capability is unique in that it demonstrates how cooperation allows the vehicles to accurately navigate beyond the RF communication range. One vehicle stops and uses its corrected GPS position to re-initialize its receiver to become the DGPS correction station for the other vehicles. Error in position accumulates each time a new vehicle takes over the DGPS duties. The accumulation in error is accurately modeled as a random walk phenomenon. This paper demonstrates how useful accuracy can be maintained beyond the vehicle's range.

  15. Dual motor drive vehicle speed synchronization and coordination control strategy

    NASA Astrophysics Data System (ADS)

    Huang, Hao; Tu, Qunzhang; Jiang, Chenming; Ma, Limin; Li, Pei; Zhang, Hongxing

    2018-04-01

    Multi-motor driven systems are more and more widely used in the field of electric engineering vehicles, as a result of the road conditions and the variable load of engineering vehicles, makes multi-motors synchronization coordinated control system as a key point of the development of the electric vehicle drive system. This paper based on electrical machinery transmission speed in the process of engineering vehicles headed for coordinated control problem, summarized control strategies at home and abroad in recent years, made analysis and comparison of the characteristics, finally discussed the trend of development of the multi-motor coordination control, provided a reference for synchronized control system research of electric drive engineering vehicles.

  16. Fault tolerant and lifetime control architecture for autonomous vehicles

    NASA Astrophysics Data System (ADS)

    Bogdanov, Alexander; Chen, Yi-Liang; Sundareswaran, Venkataraman; Altshuler, Thomas

    2008-04-01

    Increased vehicle autonomy, survivability and utility can provide an unprecedented impact on mission success and are one of the most desirable improvements for modern autonomous vehicles. We propose a general architecture of intelligent resource allocation, reconfigurable control and system restructuring for autonomous vehicles. The architecture is based on fault-tolerant control and lifetime prediction principles, and it provides improved vehicle survivability, extended service intervals, greater operational autonomy through lower rate of time-critical mission failures and lesser dependence on supplies and maintenance. The architecture enables mission distribution, adaptation and execution constrained on vehicle and payload faults and desirable lifetime. The proposed architecture will allow managing missions more efficiently by weighing vehicle capabilities versus mission objectives and replacing the vehicle only when it is necessary.

  17. Vehicle dynamics control of four in-wheel motor drive electric vehicle using gain scheduling based on tyre cornering stiffness estimation

    NASA Astrophysics Data System (ADS)

    Xiong, Lu; Yu, Zhuoping; Wang, Yang; Yang, Chen; Meng, Yufeng

    2012-06-01

    This paper focuses on the vehicle dynamic control system for a four in-wheel motor drive electric vehicle, aiming at improving vehicle stability under critical driving conditions. The vehicle dynamics controller is composed of three modules, i.e. motion following control, control allocation and vehicle state estimation. Considering the strong nonlinearity of the tyres under critical driving conditions, the yaw motion of the vehicle is regulated by gain scheduling control based on the linear quadratic regulator theory. The feed-forward and feedback gains of the controller are updated in real-time by online estimation of the tyre cornering stiffness, so as to ensure the control robustness against environmental disturbances as well as parameter uncertainty. The control allocation module allocates the calculated generalised force requirements to each in-wheel motor based on quadratic programming theory while taking the tyre longitudinal/lateral force coupling characteristic into consideration. Simulations under a variety of driving conditions are carried out to verify the control algorithm. Simulation results indicate that the proposed vehicle stability controller can effectively stabilise the vehicle motion under critical driving conditions.

  18. Vehicle active steering control research based on two-DOF robust internal model control

    NASA Astrophysics Data System (ADS)

    Wu, Jian; Liu, Yahui; Wang, Fengbo; Bao, Chunjiang; Sun, Qun; Zhao, Youqun

    2016-07-01

    Because of vehicle's external disturbances and model uncertainties, robust control algorithms have obtained popularity in vehicle stability control. The robust control usually gives up performance in order to guarantee the robustness of the control algorithm, therefore an improved robust internal model control(IMC) algorithm blending model tracking and internal model control is put forward for active steering system in order to reach high performance of yaw rate tracking with certain robustness. The proposed algorithm inherits the good model tracking ability of the IMC control and guarantees robustness to model uncertainties. In order to separate the design process of model tracking from the robustness design process, the improved 2 degree of freedom(DOF) robust internal model controller structure is given from the standard Youla parameterization. Simulations of double lane change maneuver and those of crosswind disturbances are conducted for evaluating the robust control algorithm, on the basis of a nonlinear vehicle simulation model with a magic tyre model. Results show that the established 2-DOF robust IMC method has better model tracking ability and a guaranteed level of robustness and robust performance, which can enhance the vehicle stability and handling, regardless of variations of the vehicle model parameters and the external crosswind interferences. Contradiction between performance and robustness of active steering control algorithm is solved and higher control performance with certain robustness to model uncertainties is obtained.

  19. Dynamic Curvature Steering Control for Autonomous Vehicle: Performance Analysis

    NASA Astrophysics Data System (ADS)

    Aizzat Zakaria, Muhammad; Zamzuri, Hairi; Amri Mazlan, Saiful

    2016-02-01

    This paper discusses the design of dynamic curvature steering control for autonomous vehicle. The lateral control and longitudinal control are discussed in this paper. The controller is designed based on the dynamic curvature calculation to estimate the path condition and modify the vehicle speed and steering wheel angle accordingly. In this paper, the simulation results are presented to show the capability of the controller to track the reference path. The controller is able to predict the path and modify the vehicle speed to suit the path condition. The effectiveness of the controller is shown in this paper whereby identical performance is achieved with the benchmark but with extra curvature adaptation capabilites.

  20. Attitude and Translation Control of a Solar Sail Vehicle

    NASA Technical Reports Server (NTRS)

    Singh, Gurkirpal

    2008-01-01

    A report discusses the ability to control the attitude and translation degrees-of-freedom of a solar sail vehicle by changing its center of gravity. A movement of the spacecraft s center of mass causes solar-pressure force to apply a torque to the vehicle. At the compact core of the solar-sail vehicle lies the spacecraft bus which is a large fraction of the total vehicle mass. In this concept, the bus is attached to the spacecraft by two single degree-of-freedom linear tracks. This allows relative movement of the bus in the sail plane. At the null position, the resulting solar pressure applies no torque to the vehicle. But any deviation of the bus from the null creates an offset between the spacecraft center of mass and center of solar radiation pressure, resulting in a solar-pressure torque on the vehicle which changes the vehicle attitude. Two of the three vehicle degrees of freedom can be actively controlled in this manner. The third, the roll about the sunline, requires a low-authority vane/propulsive subsystem. Translation control of the vehicle is achieved by directing the solar-pressure-induced force in the proper inertial direction. This requires attitude control. Attitude and translation degrees-of-freedom are therefore coupled. A guidance law is proposed, which allows the vehicle to stationkeep at an appropriate point on the inertially-rotating Sun-Earth line. Power requirements for moving the bus are minimal. Extensive software simulations have been performed to demonstrate the feasibility of this concept.

  1. Simple control-theoretic models of human steering activity in visually guided vehicle control

    NASA Technical Reports Server (NTRS)

    Hess, Ronald A.

    1991-01-01

    A simple control theoretic model of human steering or control activity in the lateral-directional control of vehicles such as automobiles and rotorcraft is discussed. The term 'control theoretic' is used to emphasize the fact that the model is derived from a consideration of well-known control system design principles as opposed to psychological theories regarding egomotion, etc. The model is employed to emphasize the 'closed-loop' nature of tasks involving the visually guided control of vehicles upon, or in close proximity to, the earth and to hypothesize how changes in vehicle dynamics can significantly alter the nature of the visual cues which a human might use in such tasks.

  2. Enhancing vehicle cornering limit through sideslip and yaw rate control

    NASA Astrophysics Data System (ADS)

    Lu, Qian; Gentile, Pierangelo; Tota, Antonio; Sorniotti, Aldo; Gruber, Patrick; Costamagna, Fabio; De Smet, Jasper

    2016-06-01

    Fully electric vehicles with individually controlled drivetrains can provide a high degree of drivability and vehicle safety, all while increasing the cornering limit and the 'fun-to-drive' aspect. This paper investigates a new approach on how sideslip control can be integrated into a continuously active yaw rate controller to extend the limit of stable vehicle cornering and to allow sustained high values of sideslip angle. The controllability-related limitations of integrated yaw rate and sideslip control, together with its potential benefits, are discussed through the tools of multi-variable feedback control theory and non-linear phase-plane analysis. Two examples of integrated yaw rate and sideslip control systems are presented and their effectiveness is experimentally evaluated and demonstrated on a four-wheel-drive fully electric vehicle prototype. Results show that the integrated control system allows safe operation at the vehicle cornering limit at a specified sideslip angle independent of the tire-road friction conditions.

  3. Control Relevant Modeling and Design of Scramjet-Powered Hypersonic Vehicles

    NASA Astrophysics Data System (ADS)

    Dickeson, Jeffrey James

    This report provides an overview of scramjet-powered hypersonic vehicle modeling and control challenges. Such vehicles are characterized by unstable non-minimum phase dynamics with significant coupling and low thrust margins. Recent trends in hypersonic vehicle research are summarized. To illustrate control relevant design issues and tradeoffs, a generic nonlinear 3DOF longitudinal dynamics model capturing aero-elastic-propulsive interactions for wedge-shaped vehicle is used. Limitations of the model are discussed and numerous modifications have been made to address control relevant needs. Two different baseline configurations are examined over a two-stage to orbit ascent trajectory. The report highlights how vehicle level-flight static (trim) and dynamic properties change over the trajectory. Thermal choking constraints are imposed on control system design as a direct consequence of having a finite FER margin. The implication of this state-dependent nonlinear FER margin constraint, the right half plane (RHP) zero, and lightly damped flexible modes, on control system bandwidth (BW) and FPA tracking has been discussed. A control methodology has been proposed that addresses the above dynamics while providing some robustness to modeling uncertainty. Vehicle closure (the ability to fly a trajectory segment subject to constraints) is provided through a proposed vehicle design methodology. The design method attempts to use open loop metrics whenever possible to design the vehicle. The design method is applied to a vehicle/control law closed loop nonlinear simulation for validation. The 3DOF longitudinal modeling results are validated against a newly released NASA 6DOF code.

  4. Intelligent vehicle control: Opportunities for terrestrial-space system integration

    NASA Technical Reports Server (NTRS)

    Shoemaker, Charles

    1994-01-01

    For 11 years the Department of Defense has cooperated with a diverse array of other Federal agencies including the National Institute of Standards and Technology, the Jet Propulsion Laboratory, and the Department of Energy, to develop robotics technology for unmanned ground systems. These activities have addressed control system architectures supporting sharing of tasks between the system operator and various automated subsystems, man-machine interfaces to intelligent vehicles systems, video compression supporting vehicle driving in low data rate digital communication environments, multiple simultaneous vehicle control by a single operator, path planning and retrace, and automated obstacle detection and avoidance subsystem. Performance metrics and test facilities for robotic vehicles were developed permitting objective performance assessment of a variety of operator-automated vehicle control regimes. Progress in these areas will be described in the context of robotic vehicle testbeds specifically developed for automated vehicle research. These initiatives, particularly as regards the data compression, task sharing, and automated mobility topics, also have relevance in the space environment. The intersection of technology development interests between these two communities will be discussed in this paper.

  5. Minimum fuel control of a vehicle with a continuously variable transmission. [control system simulation

    NASA Technical Reports Server (NTRS)

    Burghart, J. H.; Donoghue, J. F.

    1980-01-01

    The design and evaluation of a control system for a sedan with a heat engine and a continuously variable transmission, is considered in a effort to minimize fuel consumption and achieve satisfactory dynamic response of vehicle variables as the vehicle is driven over a standard driving cycle. Even though the vehicle system was highly nonlinear, attention was restricted to linear control algorithms which could be easily understood and implemented demonstrated by simulation. Simulation results also revealed that the vehicle could exhibit unexpected dynamic behavior which must be taken into account in any control system design.

  6. A new controller for battery-powered electric vehicles

    NASA Technical Reports Server (NTRS)

    Belsterling, C. A.; Stone, J.

    1980-01-01

    This paper describes the development, under a NASA/DOE contract, of a new concept for efficient and reliable control of battery-powered vehicles. It avoids the detrimental effects of pulsed-power controllers like the SCR 'chopper' by using rotating machines to meter continuous currents to the traction motor. The concept is validated in a proof-of-principle demonstration system and a complete vehicle is simulated on an analog computer. Test results show exceptional promise for a full-scale system. Optimum control strategies to minimize controller weight are developed by means of the simulated vehicle. The design for an Engineering Model is then prepared in the form of a practical, compact two-bearing package with forced air cooling. Predicted performance is outstanding, with controller efficiency of over 90% at high speed.

  7. Slip control for LIM propelled transit vehicles

    NASA Astrophysics Data System (ADS)

    Wallace, A. K.; Parker, J. H.; Dawson, G. E.

    1980-09-01

    Short stator linear induction motors, with an iron-backed aluminum sheet reaction rail and powered by a controlled inverter, have been selected as the propulsion system for transit vehicles in an intermediate capacity system (12-20,000 pphpd). The linear induction motor is capable of adhesion independent braking and acceleration levels which permit safe, close headways. In addition, simple control is possible allowing moving block automatic train control. This paper presents a slip frequency control scheme for the LIM. Experimental results for motoring and braking obtained from a test vehicle are also presented. These values are compared with theoretical predictions.

  8. Adaptive powertrain control for plugin hybrid electric vehicles

    DOEpatents

    Kedar-Dongarkar, Gurunath; Weslati, Feisel

    2013-10-15

    A powertrain control system for a plugin hybrid electric vehicle. The system comprises an adaptive charge sustaining controller; at least one internal data source connected to the adaptive charge sustaining controller; and a memory connected to the adaptive charge sustaining controller for storing data generated by the at least one internal data source. The adaptive charge sustaining controller is operable to select an operating mode of the vehicle's powertrain along a given route based on programming generated from data stored in the memory associated with that route. Further described is a method of adaptively controlling operation of a plugin hybrid electric vehicle powertrain comprising identifying a route being traveled, activating stored adaptive charge sustaining mode programming for the identified route and controlling operation of the powertrain along the identified route by selecting from a plurality of operational modes based on the stored adaptive charge sustaining mode programming.

  9. Interactive effects of chemical and biological controls on food-web composition in saline prairie lakes.

    PubMed

    Cooper, Ryan N; Wissel, Björn

    2012-11-27

    Salinity is restricting habitatability for many biota in prairie lakes due to limited physiological abilities to cope with increasing osmotic stress. Yet, it remains unclear how salinity effects vary among major taxonomic groups and what role other environmental parameters play in shaping food-web composition. To answer these questions, we sampled fish, zooplankton and littoral macroinvertebrates in 20 prairie lakes (Saskatchewan, Canada) characterized by large gradients in water chemistry and lake morphometry. We showed that salinity thresholds differed among major taxonomic groups, as most fishes were absent above salinities of 2 g L-1, while littoral macroinvertebrates were ubiquitous. Zooplankton occurred over the whole salinity range, but changed taxonomic composition as salinity increased. Subsequently, the complexity of fish community (diversity) was associated with large changes in invertebrate communities. The directional changes in invertebrate communities to smaller taxa indicated that complex fish assemblages resulted in higher predation pressure. Most likely, as the complexity of fish community decreased, controls of invertebrate assemblages shifted from predation to competition and ultimately to productivity in hypersaline lakes. Surprisingly, invertebrate predators did not thrive in the absence of fishes in these systems. Furthermore, the here identified salinity threshold for fishes was too low to be a result of osmotic stress. Hence, winterkill was likely an important factor eliminating fishes in low salinity lakes that had high productivity and shallow water depth. Ultimately, while salinity was crucial, intricate combinations of chemical and biological mechanisms also played a major role in controlling the assemblages of major taxonomic groups in prairie lakes.

  10. Interactive effects of chemical and biological controls on food-web composition in saline prairie lakes

    PubMed Central

    2012-01-01

    Salinity is restricting habitatability for many biota in prairie lakes due to limited physiological abilities to cope with increasing osmotic stress. Yet, it remains unclear how salinity effects vary among major taxonomic groups and what role other environmental parameters play in shaping food-web composition. To answer these questions, we sampled fish, zooplankton and littoral macroinvertebrates in 20 prairie lakes (Saskatchewan, Canada) characterized by large gradients in water chemistry and lake morphometry. We showed that salinity thresholds differed among major taxonomic groups, as most fishes were absent above salinities of 2 g L-1, while littoral macroinvertebrates were ubiquitous. Zooplankton occurred over the whole salinity range, but changed taxonomic composition as salinity increased. Subsequently, the complexity of fish community (diversity) was associated with large changes in invertebrate communities. The directional changes in invertebrate communities to smaller taxa indicated that complex fish assemblages resulted in higher predation pressure. Most likely, as the complexity of fish community decreased, controls of invertebrate assemblages shifted from predation to competition and ultimately to productivity in hypersaline lakes. Surprisingly, invertebrate predators did not thrive in the absence of fishes in these systems. Furthermore, the here identified salinity threshold for fishes was too low to be a result of osmotic stress. Hence, winterkill was likely an important factor eliminating fishes in low salinity lakes that had high productivity and shallow water depth. Ultimately, while salinity was crucial, intricate combinations of chemical and biological mechanisms also played a major role in controlling the assemblages of major taxonomic groups in prairie lakes. PMID:23186395

  11. Broadband vehicle-to-vehicle communication using an extended autonomous cruise control sensor

    NASA Astrophysics Data System (ADS)

    Heddebaut, M.; Rioult, J.; Ghys, J. P.; Gransart, Ch; Ambellouis, S.

    2005-06-01

    For several years road vehicle autonomous cruise control (ACC) systems as well as anti-collision radar have been developed. Several manufacturers currently sell this equipment. The current generation of ACC sensors only track the first preceding vehicle to deduce its speed and position. These data are then used to compute, manage and optimize a safety distance between vehicles, thus providing some assistance to car drivers. However, in real conditions, to elaborate and update a real time driving solution, car drivers use information about speed and position of preceding and following vehicles. This information is essentially perceived using the driver's eyes, binocular stereoscopic vision performed through the windscreens and rear-view mirrors. Furthermore, within a line of vehicles, the frontal road perception of the first vehicle is very particular and highly significant. Currently, all these available data remain strictly on-board the vehicle that has captured the perception information and performed these measurements. To get the maximum effectiveness of all these approaches, we propose that this information be shared in real time with the following vehicles, within the convoy. On the basis of these considerations, this paper technically explores a cost-effective solution to extend the basic ACC sensor function in order to simultaneously provide a vehicle-to-vehicle radio link. This millimetre wave radio link transmits relevant broadband perception data (video, localization...) to following vehicles, along the line of vehicles. The propagation path between the vehicles uses essentially grazing angles of incidence of signals over the road surface including millimetre wave paths beneath the cars.

  12. Semi-active control of tracked vehicle suspension incorporating magnetorheological dampers

    NASA Astrophysics Data System (ADS)

    Ata, W. G.; Salem, A. M.

    2017-05-01

    In past years, the application of magnetorheological (MR) and electrorheological dampers in vehicle suspension has been widely studied, mainly for the purpose of vibration control. This paper presents theoretical study to identify an appropriate semi-active control method for MR-tracked vehicle suspension. Three representative control algorithms are simulated including the skyhook, hybrid and fuzzy-hybrid controllers. A seven degrees-of-freedom tracked vehicle suspension model incorporating MR dampers has been adopted for comparison between the performance of the three controllers. The model differential equations are derived based on Newton's second law of motion and the proposed control methods are developed. The performance of each control method under bump and sinusoidal road profiles for different vehicle speeds is simulated and compared with the performance of the conventional suspension system in time and frequency domains. The results show that the performance of tracked vehicle suspension with MR dampers is substantially improved. Moreover, the fuzzy-hybrid controller offers an excellent integrated performance in reducing the body accelerations as well as wheel bounce responses compared with the classical skyhook and hybrid controllers.

  13. Improved LTVMPC design for steering control of autonomous vehicle

    NASA Astrophysics Data System (ADS)

    Velhal, Shridhar; Thomas, Susy

    2017-01-01

    An improved linear time varying model predictive control for steering control of autonomous vehicle running on slippery road is presented. Control strategy is designed such that the vehicle will follow the predefined trajectory with highest possible entry speed. In linear time varying model predictive control, nonlinear vehicle model is successively linearized at each sampling instant. This linear time varying model is used to design MPC which will predict the future horizon. By incorporating predicted input horizon in each successive linearization the effectiveness of controller has been improved. The tracking performance using steering with front wheel and braking at four wheels are presented to illustrate the effectiveness of the proposed method.

  14. Method of Controlling Steering of a Ground Vehicle

    NASA Technical Reports Server (NTRS)

    Guo, Raymond (Inventor); Atluri, Venkata Prasad (Inventor); Bluethmann, William J. (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Dawson, Andrew D. (Inventor)

    2016-01-01

    A method of controlling steering of a vehicle through setting wheel angles of a plurality of modular electronic corner assemblies (eModules) is provided. The method includes receiving a driving mode selected from a mode selection menu. A position of a steering input device is determined in a master controller. A velocity of the vehicle is determined, in the master controller, when the determined position of the steering input device is near center. A drive mode request corresponding to the selected driving mode to the plurality of steering controllers is transmitted to the master controller. A required steering angle of each of the plurality of eModules is determined, in the master controller, as a function of the determined position of the steering input device, the determined velocity of the vehicle, and the selected first driving mode. The eModules are set to the respective determined steering angles.

  15. Cooperative Control of Distributed Autonomous Vehicles in Adversarial Environments

    DTIC Science & Technology

    2006-08-14

    COOPERATIVE CONTROL OF DISTRIBUTED AUTONOMOUS VEHICLES IN ADVERSARIAL ENVIRONMENTS Grant #F49620–01–1–0361 Final Report Jeff Shamma Department of...CONTRACT NUMBER F49620-01-1-0361 5b. GRANT NUMBER 4. TITLE AND SUBTITLE COOPERATIVE CONTROL OF DISTRIBUTED AUTONOMOUS VEHICLES IN...single dominant language or a distribution of languages. A relation to multivehicle systems is understanding how highly autonomous vehicles on extended

  16. A Queueing Model for Supervisory Control of Unmanned Autonomous Vehicles

    DTIC Science & Technology

    2013-09-01

    Autonomous Vehicles Joseph DiVita, PhD Robert L. Morris Maria Olinda Rodas SSC Pacific Approved...298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 09–2013 Final A Queueing Model for Supervisory Control of Unmanned Autonomous Vehicles Joseph...Mission Area: Command and Control, Queueing Model; Supervisory Control; Unmanned Autonomous Vehicles M. O. Rodas U U U U 38 (619)

  17. A PEMFC hybrid electric vehicle real time control system

    NASA Astrophysics Data System (ADS)

    Sun, Hongqiao

    In recent years, environmental friendly technologies and alternative energy solutions have drawn a lot of public attentions due to global energy crisis and pollution issues. Fuel cell (FC), a technology invented almost at the same time as the internal combustion (IC) engine, is now the focus of the automotive industry again. The fuel cell vehicle (FCV) has zero emission and its efficiency is significantly higher than the conventional IC engine power vehicles. Among a variety of FCV technologies, proton exchange membrane (PEM) FC vehicle appears to be far more attractive and mature. The prototype PEMFC vehicle has been developed and demonstrated to the public by nearly all the major automotive manufacturers in recent years. However, to the interest of the public research, publications and documentations on the PEMFC vehicle technology are rarely available due to its proprietary nature, which essentially makes it a secured technology. This dissertation demonstrates a real world application of a PEMFC hybrid electric vehicle. Through presenting the vehicle design concept, developing the real time control system and generating generic operation principles, this dissertation targets at establishing the public knowledge base on this new technology. A complete PEMFC hybrid electric vehicle design, including vehicle components layout, process flow diagram, real time control system architecture, subsystem structures and control algorithms, is presented in order to help understand the whole vehicle system. The design concept is validated through the vehicle demonstration. Generic operating principles are established along with the validation process, which helps populate this emerging technology. Thereafter, further improvements and future research directions are discussed.

  18. 77 FR 30765 - Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems for Heavy Vehicles

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... truck tractors and large buses are designed to reduce untripped rollovers and mitigate severe understeer... vehicles. A roll stability control (RSC) system is designed to prevent rollover by decelerating the vehicle... vehicle operation, as well as factors related to roadway design and road surface properties, can cause...

  19. Bibliography on Ground Vehicle Communications & Control : A KWIC Index

    DOT National Transportation Integrated Search

    1971-08-01

    This bibliography, or the subject of communication and control of ground vehicles, covers the fields of land-mobile communication, computer-aided traffic control, communication with high speed ground vehicles and radio frequency noise. Emphasis is pl...

  20. Control-Relevant Modeling, Analysis, and Design for Scramjet-Powered Hypersonic Vehicles

    NASA Technical Reports Server (NTRS)

    Rodriguez, Armando A.; Dickeson, Jeffrey J.; Sridharan, Srikanth; Benavides, Jose; Soloway, Don; Kelkar, Atul; Vogel, Jerald M.

    2009-01-01

    Within this paper, control-relevant vehicle design concepts are examined using a widely used 3 DOF (plus flexibility) nonlinear model for the longitudinal dynamics of a generic carrot-shaped scramjet powered hypersonic vehicle. Trade studies associated with vehicle/engine parameters are examined. The impact of parameters on control-relevant static properties (e.g. level-flight trimmable region, trim controls, AOA, thrust margin) and dynamic properties (e.g. instability and right half plane zero associated with flight path angle) are examined. Specific parameters considered include: inlet height, diffuser area ratio, lower forebody compression ramp inclination angle, engine location, center of gravity, and mass. Vehicle optimizations is also examined. Both static and dynamic considerations are addressed. The gap-metric optimized vehicle is obtained to illustrate how this control-centric concept can be used to "reduce" scheduling requirements for the final control system. A classic inner-outer loop control architecture and methodology is used to shed light on how specific vehicle/engine design parameter selections impact control system design. In short, the work represents an important first step toward revealing fundamental tradeoffs and systematically treating control-relevant vehicle design.

  1. Automated mixed traffic transit vehicle microprocessor controller

    NASA Technical Reports Server (NTRS)

    Marks, R. A.; Cassell, P.; Johnston, A. R.

    1981-01-01

    An improved Automated Mixed Traffic Vehicle (AMTV) speed control system employing a microprocessor and transistor chopper motor current controller is described and its performance is presented in terms of velocity versus time curves. The on board computer hardware and software systems are described as is the software development system. All of the programming used in this controller was implemented using FORTRAN. This microprocessor controller made possible a number of safety features and improved the comfort associated with starting and shopping. In addition, most of the vehicle's performance characteristics can be altered by simple program parameter changes. A failure analysis of the microprocessor controller was generated and the results are included. Flow diagrams for the speed control algorithms and complete FORTRAN code listings are also included.

  2. Electronic differential control of 2WD electric vehicle considering steering stability

    NASA Astrophysics Data System (ADS)

    Hua, Yiding; Jiang, Haobin; Geng, Guoqing

    2017-03-01

    Aiming at the steering wheel differential steering control technology of rear wheel independent driving electric wheel, considering the assisting effect of electronic differential control on vehicle steering, based on the high speed steering characteristic of electric wheel car, the electronic differential speed of auxiliary wheel steering is also studied. A yaw moment control strategy is applied to the vehicle at high speed. Based on the vehicle stability reference value, yaw rate is used to design the fuzzy controller to distribute the driving wheel torque. The simulation results show that the basic electronic differential speed function is realized based on the yaw moment control strategy, while the vehicle stability control is improved and the driving safety is enhanced. On the other hand, the torque control strategy can also assist steering of vehicle.

  3. Hypersonic vehicle control law development using H(infinity) and micron-synthesis

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.; Mcminn, John D.; Shaughnessy, John D.; Chowdhry, Rajiv S.

    1993-01-01

    Hypersonic vehicle control law development using H(infinity) and mu-synthesis is discussed. Airbreathing SSTO vehicles has a mutli-faceted mission that includes orbital operations, as well as re-entry and descent culminating in horizontal landing. However, the most challenging part of the operations is the ascent to orbit. The airbreathing propulsion requires lengthy atmospheric flight that may last as long as 30 minutes and take the vehicle half way around the globe. The vehicles's ascent is characterized by tight payload to orbit margins which translate into minimum fuel orbit as the performance criteria. Issues discussed include: SSTO airbreathing vehicle issues; control system performance requirements; robust control law framework; H(infinity) controller frequency analysis; and mu controller frequency analysis.

  4. 32 CFR 228.4 - Control of vehicles on protected property.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Control of vehicles on protected property. 228.4... (CONTINUED) MISCELLANEOUS SECURITY PROTECTIVE FORCE § 228.4 Control of vehicles on protected property. Drivers of all vehicles entering or while on protected property shall comply with the signals and...

  5. 32 CFR 228.4 - Control of vehicles on protected property.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Control of vehicles on protected property. 228.4... (CONTINUED) MISCELLANEOUS SECURITY PROTECTIVE FORCE § 228.4 Control of vehicles on protected property. Drivers of all vehicles entering or while on protected property shall comply with the signals and...

  6. 32 CFR 228.4 - Control of vehicles on protected property.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Control of vehicles on protected property. 228.4... (CONTINUED) MISCELLANEOUS SECURITY PROTECTIVE FORCE § 228.4 Control of vehicles on protected property. Drivers of all vehicles entering or while on protected property shall comply with the signals and...

  7. 32 CFR 228.4 - Control of vehicles on protected property.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Control of vehicles on protected property. 228.4... (CONTINUED) MISCELLANEOUS SECURITY PROTECTIVE FORCE § 228.4 Control of vehicles on protected property. Drivers of all vehicles entering or while on protected property shall comply with the signals and...

  8. Cooperative Control of Multiple Unmanned Autonomous Vehicles

    DTIC Science & Technology

    2005-06-03

    I I Final Report 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Cooperative Control of Multiple Unmanned Autonomous Vehicles F49620-01-1-0337 6. AUTHOR(S... Autonomous Vehicles Final Report Kendall E. Nygard Department of Computer Science and Operations Research North Dakota State University Fargo, ND 58105-5164

  9. A Flight Control Approach for Small Reentry Vehicles

    NASA Technical Reports Server (NTRS)

    Bevacqoa, Tim; Adams, Tony; Zhu. J. Jim; Rao, P. Prabhakara

    2004-01-01

    Flight control of small crew return vehicles during atmospheric reentry will be an important technology in any human space flight mission undertaken in the future. The control system presented in this paper is applicable to small crew return vehicles in which reaction control system (RCS) thrusters are the only actuators available for attitude control. The control system consists of two modules: (i) the attitude controller using the trajectory linearization control (TLC) technique, and (ii) the reaction control system (RCS) control allocation module using a dynamic table-lookup technique. This paper describes the design and implementation of the TLC attitude control and the dynamic table-lookup RCS control allocation for nonimal flight along with design verification test results.

  10. Slip Ratio Estimation and Regenerative Brake Control for Decelerating Electric Vehicles without Detection of Vehicle Velocity and Acceleration

    NASA Astrophysics Data System (ADS)

    Suzuki, Toru; Fujimoto, Hiroshi

    In slip ratio control systems, it is necessary to detect the vehicle velocity in order to obtain the slip ratio. However, it is very difficult to measure this velocity directly. We have proposed slip ratio estimation and control methods that do not require the vehicle velocity with acceleration. In this paper, the slip ratio estimation and control methods are proposed without detecting the vehicle velocity and acceleration when it is decelerating. We carried out simulations and experiments by using an electric vehicle to verify the effectiveness of the proposed method.

  11. The use of visual cues for vehicle control and navigation

    NASA Technical Reports Server (NTRS)

    Hart, Sandra G.; Battiste, Vernol

    1991-01-01

    At least three levels of control are required to operate most vehicles: (1) inner-loop control to counteract the momentary effects of disturbances on vehicle position; (2) intermittent maneuvers to avoid obstacles, and (3) outer-loop control to maintain a planned route. Operators monitor dynamic optical relationships in their immediate surroundings to estimate momentary changes in forward, lateral, and vertical position, rates of change in speed and direction of motion, and distance from obstacles. The process of searching the external scene to find landmarks (for navigation) is intermittent and deliberate, while monitoring and responding to subtle changes in the visual scene (for vehicle control) is relatively continuous and 'automatic'. However, since operators may perform both tasks simultaneously, the dynamic optical cues available for a vehicle control task may be determined by the operator's direction of gaze for wayfinding. An attempt to relate the visual processes involved in vehicle control and wayfinding is presented. The frames of reference and information used by different operators (e.g., automobile drivers, airline pilots, and helicopter pilots) are reviewed with particular emphasis on the special problems encountered by helicopter pilots flying nap of the earth (NOE). The goal of this overview is to describe the context within which different vehicle control tasks are performed and to suggest ways in which the use of visual cues for geographical orientation might influence visually guided control activities.

  12. Integrated Vehicle Ground Vibration Testing in Support of Launch Vehicle Loads and Controls Analysis

    NASA Technical Reports Server (NTRS)

    Askins, Bruce R.; Davis, Susan R.; Salyer, Blaine H.; Tuma, Margaret L.

    2008-01-01

    All structural systems possess a basic set of physical characteristics unique to that system. These unique physical characteristics include items such as mass distribution and damping. When specified, they allow engineers to understand and predict how a structural system behaves under given loading conditions and different methods of control. These physical properties of launch vehicles may be predicted by analysis or measured by certain types of tests. Generally, these properties are predicted by analysis during the design phase of a launch vehicle and then verified by testing before the vehicle becomes operational. A ground vibration test (GVT) is intended to measure by test the fundamental dynamic characteristics of launch vehicles during various phases of flight. During the series of tests, properties such as natural frequencies, mode shapes, and transfer functions are measured directly. These data will then be used to calibrate loads and control systems analysis models for verifying analyses of the launch vehicle. NASA manned launch vehicles have undergone ground vibration testing leading to the development of successful launch vehicles. A GVT was not performed on the inaugural launch of the unmanned Delta III which was lost during launch. Subsequent analyses indicated had a GVT been performed, it would have identified instability issues avoiding loss of the vehicle. This discussion will address GVT planning, set-up, execution and analyses, for the Saturn and Shuttle programs, and will also focus on the current and on-going planning for the Ares I and V Integrated Vehicle Ground Vibration Test (IVGVT).

  13. Geometry Modeling and Adaptive Control of Air-Breathing Hypersonic Vehicles

    NASA Astrophysics Data System (ADS)

    Vick, Tyler Joseph

    Air-breathing hypersonic vehicles have the potential to provide global reach and affordable access to space. Recent technological advancements have made scramjet-powered flight achievable, as evidenced by the successes of the X-43A and X-51A flight test programs over the last decade. Air-breathing hypersonic vehicles present unique modeling and control challenges in large part due to the fact that scramjet propulsion systems are highly integrated into the airframe, resulting in strongly coupled and often unstable dynamics. Additionally, the extreme flight conditions and inability to test fully integrated vehicle systems larger than X-51 before flight leads to inherent uncertainty in hypersonic flight. This thesis presents a means to design vehicle geometries, simulate vehicle dynamics, and develop and analyze control systems for hypersonic vehicles. First, a software tool for generating three-dimensional watertight vehicle surface meshes from simple design parameters is developed. These surface meshes are compatible with existing vehicle analysis tools, with which databases of aerodynamic and propulsive forces and moments can be constructed. A six-degree-of-freedom nonlinear dynamics simulation model which incorporates this data is presented. Inner-loop longitudinal and lateral control systems are designed and analyzed utilizing the simulation model. The first is an output feedback proportional-integral linear controller designed using linear quadratic regulator techniques. The second is a model reference adaptive controller (MRAC) which augments this baseline linear controller with an adaptive element. The performance and robustness of each controller are analyzed through simulated time responses to angle-of-attack and bank angle commands, while various uncertainties are introduced. The MRAC architecture enables the controller to adapt in a nonlinear fashion to deviations from the desired response, allowing for improved tracking performance, stability, and

  14. Integrated Vehicle Ground Vibration Testing in Support of Launch Vehicle Loads and Controls Analysis

    NASA Technical Reports Server (NTRS)

    Tuma, Margaret L.; Chenevert, Donald J.

    2009-01-01

    NASA has conducted dynamic tests on each major launch vehicle during the past 45 years. Each test provided invaluable data to correlate and correct analytical models. GVTs result in hardware changes to Saturn and Space Shuttle, ensuring crew and vehicle safety. Ares I IVGT will provide test data such as natural frequencies, mode shapes, and damping to support successful Ares I flights. Testing will support controls analysis by providing data to reduce model uncertainty. Value of testing proven by past launch vehicle successes and failures. Performing dynamic testing on Ares vehicles will provide confidence that the launch vehicles will be safe and successful in their missions.

  15. 78 FR 32223 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ...-OAR-2011-0135; FRL-9818-5] RIN 2060-A0 Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards AGENCY: Environmental Protection Agency (EPA). ACTION: Notice... extension of the public comment period for the proposed rule ``Control of Air Pollution from Motor Vehicles...

  16. Adaptive Attitude Control of the Crew Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Muse, Jonathan

    2010-01-01

    An H(sub infinity)-NMA architecture for the Crew Launch Vehicle was developed in a state feedback setting. The minimal complexity adaptive law was shown to improve base line performance relative to a performance metric based on Crew Launch Vehicle design requirements for all most all of the Worst-on-Worst dispersion cases. The adaptive law was able to maintain stability for some dispersions that are unstable with the nominal control law. Due to the nature of the H(sub infinity)-NMA architecture, the augmented adaptive control signal has low bandwidth which is a great benefit for a manned launch vehicle.

  17. Vehicle rollover risk and electronic stability control systems.

    PubMed

    MacLennan, P A; Marshall, T; Griffin, R; Purcell, M; McGwin, G; Rue, L W

    2008-06-01

    Electronic stability control (ESC) systems were developed to reduce motor vehicle collisions (MVCs) caused by loss of control. Introduced in Europe in 1995 and in the USA in 1996, ESC is designed to improve vehicle lateral stability by electronically detecting and automatically assisting drivers in unfavorable situations. To examine the relationship between vehicle rollover risk and presence of ESC using a large national database of MVCs. A retrospective cohort study for the period 1995 through 2006 was carried out using data obtained from the National Automotive Sampling System General Estimates System. All passenger cars and sport utility vehicles (SUVs)/vans of model year 1996 and later were eligible. Vehicle ESC (unavailable, optional, standard) was determined on the basis of make, model, and model year. Risk ratios (RRs) and 95% CIs were calculated to compare rollover risk by vehicle ESC group. For all crashes, vehicles equipped with standard ESC had decreased risk of rollover (RR = 0.62, 95% CI 0.50 to 0.77) compared with vehicles with ESC unavailable. The association was consistent for single-vehicle MVCs (RR = 0.61, 95% CI 0.46 to 0.82); passenger cars had decreased rollover risk (RR = 0.77, 95% CI 0.52 to 1.12), but SUVs/vans had a more dramatically decreased risk (RR = 0.40, 95% CI 0.26 to 0.61). This study supports previous results showing ESC to be effective in reducing the risk of rollover. ESC is more effective in SUVs/vans for rollovers related to single-vehicle MVCs.

  18. Inter-Vehicle Communication System Utilizing Autonomous Distributed Transmit Power Control

    NASA Astrophysics Data System (ADS)

    Hamada, Yuji; Sawa, Yoshitsugu; Goto, Yukio; Kumazawa, Hiroyuki

    In ad-hoc network such as inter-vehicle communication (IVC) system, safety applications that vehicles broadcast the information such as car velocity, position and so on periodically are considered. In these applications, if there are many vehicles broadcast data in a communication area, congestion incurs a problem decreasing communication reliability. We propose autonomous distributed transmit power control method to keep high communication reliability. In this method, each vehicle controls its transmit power using feed back control. Furthermore, we design a communication protocol to realize the proposed method, and we evaluate the effectiveness of proposed method using computer simulation.

  19. Sliding mode-based lateral vehicle dynamics control using tyre force measurements

    NASA Astrophysics Data System (ADS)

    Kunnappillil Madhusudhanan, Anil; Corno, Matteo; Holweg, Edward

    2015-11-01

    In this work, a lateral vehicle dynamics control based on tyre force measurements is proposed. Most of the lateral vehicle dynamics control schemes are based on yaw rate whereas tyre forces are the most important variables in vehicle dynamics as tyres are the only contact points between the vehicle and road. In the proposed method, active front steering is employed to uniformly distribute the required lateral force among the front left and right tyres. The force distribution is quantified through the tyre utilisation coefficients. In order to address the nonlinearities and uncertainties of the vehicle model, a gain scheduling sliding-mode control technique is used. In addition to stabilising the lateral dynamics, the proposed controller is able to maintain maximum lateral acceleration. The proposed method is tested and validated on a multi-body vehicle simulator.

  20. Optimizing Optics For Remotely Controlled Underwater Vehicles

    NASA Astrophysics Data System (ADS)

    Billet, A. B.

    1984-09-01

    The past decade has shown a dramatic increase in the use of unmanned tethered vehicles in worldwide marine fields. These vehicles are used for inspection, debris removal and object retrieval. With advanced robotic technology, remotely operated vehicles (ROVs) are now able to perform a variety of jobs previously accomplished only by divers. The ROVs can be used at greater depths and for riskier jobs, and safety to the diver is increased, freeing him for safer, more cost-effective tasks requiring human capabilities. Secondly, the ROV operation becomes more cost effective to use as work depth increases. At 1000 feet a diver's 10 minutes of work can cost over $100,000 including support personnel, while an ROV operational cost might be 1/20 of the diver cost per day, based on the condition that the cost for ROV operation does not change with depth, as it does for divers. In the ROV operation the television lens must be as good as the human eye, with better light gathering capability than the human eye. The RCV-150 system is an example of these advanced technology vehicles. With the requirements of manueuverability and unusual inspection, a responsive, high performance, compact vehicle was developed. The RCV-150 viewing subsystem consists of a television camera, lights, and topside monitors. The vehicle uses a low light level Newvicon television camera. The camera is equipped with a power-down iris that closes for burn protection when the power is off. The camera can pan f 50 degrees and tilt f 85 degrees on command from the surface. Four independently controlled 250 watt quartz halogen flood lamps illuminate the viewing area as required; in addition, two 250 watt spotlights are fitted. A controlled nine inch CRT monitor provides real time camera pictures for the operator. The RCV-150 vehicle component system consists of the vehicle structure, the vehicle electronics, and hydraulic system which powers the thruster assemblies and the manipulator. For this vehicle, a light

  1. Regardless-of-Speed Superconducting LSM Controlled-Repulsive MAGLEV Vehicle

    NASA Technical Reports Server (NTRS)

    Yoshida, Kinjiro; Egashira, Tatsuya; Hirai, Ryuichi

    1996-01-01

    This paper proposes a new repulsive Maglev vehicle which a superconducting linear synchronous motor (LSM) can levitate and propel simultaneously, independently of the vehicle speeds. The combined levitation and propulsion control is carried out by controlling mechanical-load angle and armature-current. Dynamic simulations show successful operations with good ride-quality by using a compact control method proposed here.

  2. Analysis and control of high-speed wheeled vehicles

    NASA Astrophysics Data System (ADS)

    Velenis, Efstathios

    In this work we reproduce driving techniques to mimic expert race drivers and obtain the open-loop control signals that may be used by auto-pilot agents driving autonomous ground wheeled vehicles. Race drivers operate their vehicles at the limits of the acceleration envelope. An accurate characterization of the acceleration capacity of the vehicle is required. Understanding and reproduction of such complex maneuvers also require a physics-based mathematical description of the vehicle dynamics. While most of the modeling issues of ground-vehicles/automobiles are already well established in the literature, lack of understanding of the physics associated with friction generation results in ad-hoc approaches to tire friction modeling. In this work we revisit this aspect of the overall vehicle modeling and develop a tire friction model that provides physical interpretation of the tire forces. The new model is free of those singularities at low vehicle speed and wheel angular rate that are inherent in the widely used empirical static models. In addition, the dynamic nature of the tire model proposed herein allows the study of dynamic effects such as transients and hysteresis. The trajectory-planning problem for an autonomous ground wheeled vehicle is formulated in an optimal control framework aiming to minimize the time of travel and maximize the use of the available acceleration capacity. The first approach to solve the optimal control problem is using numerical techniques. Numerical optimization allows incorporation of a vehicle model of high fidelity and generates realistic solutions. Such an optimization scheme provides an ideal platform to study the limit operation of the vehicle, which would not be possible via straightforward simulation. In this work we emphasize the importance of online applicability of the proposed methodologies. This underlines the need for optimal solutions that require little computational cost and are able to incorporate real, unpredictable

  3. Vehicle handling and stability control by the cooperative control of 4WS and DYC

    NASA Astrophysics Data System (ADS)

    Shen, Huan; Tan, Yun-Sheng

    2017-07-01

    This paper proposes an integrated control system that cooperates with the four-wheel steering (4WS) and direct yaw moment control (DYC) to improve the vehicle handling and stability. The design works of the four-wheel steering and DYC control are based on sliding mode control. The integration control system produces the suitable 4WS angle and corrective yaw moment so that the vehicle tracks the desired yaw rate and sideslip angle. Considering the change of the vehicle longitudinal velocity that means the comfort of driving conditions, both the driving torque and braking torque are used to generate the corrective yaw moment. Simulation results show the effectiveness of the proposed control algorithm.

  4. Guidance and control strategies for aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Naidu, Desineni S.; Hibey, Joseph L.

    1989-01-01

    The optimal control problem arising in coplanar orbital transfer employing aeroassist technology and the fuel-optimal control problem arising in orbital transfer vehicles employing aeroassist technology are addressed.

  5. Motion-mode energy method for vehicle dynamics analysis and control

    NASA Astrophysics Data System (ADS)

    Zhang, Nong; Wang, Lifu; Du, Haiping

    2014-01-01

    Vehicle motion and vibration control is a fundamental motivation for the development of advanced vehicle suspension systems. In a vehicle-fixed coordinate system, the relative motions of the vehicle between body and wheel can be classified into several dynamic stages based on energy intensity, and can be decomposed into sets of uncoupled motion-modes according to modal parameters. Vehicle motions are coupled, but motion-modes are orthogonal. By detecting and controlling the predominating vehicle motion-mode, the system cost and energy consumption of active suspensions could be reduced. A motion-mode energy method (MEM) is presented in this paper to quantify the energy contribution of each motion-mode to vehicle dynamics in real time. The control of motion-modes is prioritised according to the level of motion-mode energy. Simulation results on a 10 degree-of-freedom nonlinear full-car model with the magic-formula tyre model illustrate the effectiveness of the proposed MEM. The contribution of each motion-mode to the vehicle's dynamic behaviour is analysed under different excitation inputs from road irregularities, directional manoeuvres and braking. With the identified dominant motion-mode, novel cost-effective suspension systems, such as active reconfigurable hydraulically interconnected suspension, can possibly be used to control full-car motions with reduced energy consumption. Finally, discussion, conclusions and suggestions for future work are provided.

  6. Integration of herbicides with manual weeding for controlling the weeds in rice under saline environment.

    PubMed

    Hakim, M A; Juraimi, Abdul Shukor; Hanafi, M M; Rafii, Mohd Y; Ismail, Mohd Razi; Karim, S M Rezaul; Kausar, H

    2015-11-01

    The pot experiment was conducted to select appropriate integrated weed management method in rice under different salinity levels (0, 4 and 8 dS m(-1)). All the parameters including rice and weed measured were significantly influenced by weed control treatments at all salinity levels. Treatments including weed-free condition, Pretilachlor @0.375 kg ai ha(-1) + hand weeding, Propanil + Thiobencarb @ 0.9 kg ai ha(-1) and 1.8 kg ai ha(-1)+ hand weeding performed better under all salinity levels. Pretilachlor @ 0.375 kg ai ha(-1) with one round of hand weeding and propanil + thiobencarb 0.9 kg ai ha(-1) + 1.8 kg ai ha(-1) with one round of hand weeding were comparable to weed-free yields, and were superior to other treatments under salinity condition. Considering all the parameters, pretilachlor @ 0.375 kg ai ha(-1) + one round of hand weeding (at 65 DAT), propanil + thiobencarb 0.9 kg ai ha(-1) +1.8 kg ai ha(-1) + one round of hand weeding (at 65 DAT) gave the most effective control of weeds in rice under saline environments.

  7. Reusable Launch Vehicle Control in Multiple Time Scale Sliding Modes

    NASA Technical Reports Server (NTRS)

    Shtessel, Yuri

    1999-01-01

    A reusable launch vehicle control problem during ascent is addressed via multiple-time scaled continuous sliding mode control. The proposed sliding mode controller utilizes a two-loop structure and provides robust, de-coupled tracking of both orientation angle command profiles and angular rate command profiles in the presence of bounded external disturbances and plant uncertainties. Sliding mode control causes the angular rate and orientation angle tracking error dynamics to be constrained to linear, de-coupled, homogeneous, and vector valued differential equations with desired eigenvalues placement. The dual-time scale sliding mode controller was designed for the X-33 technology demonstration sub-orbital launch vehicle in the launch mode. 6DOF simulation results show that the designed controller provides robust, accurate, de-coupled tracking of the orientation angle command profiles in presence of external disturbances and vehicle inertia uncertainties. It creates possibility to operate the X-33 vehicle in an aircraft-like mode with reduced pre-launch adjustment of the control system.

  8. Automatic guidance control of an articulated all-wheel-steered vehicle

    NASA Astrophysics Data System (ADS)

    Kim, Young Chol; Yun, Kyong-Han; Min, Kyung-Deuk

    2014-04-01

    This paper presents automatic guidance control of a single-articulated all-wheel-steered vehicle being developed by the Korea Railroad Research Institute. The vehicle has an independent drive motor on each wheel except for the front axle. The guidance controller is designed so that the vehicle follows the given reference path within permissible lateral deviations. We use a three-input/three-output linearised model derived from the nonlinear dynamic model of the vehicle. For the purpose of simplifying the controller and making it tunable, we consider a decentralised control configuration. We first design a second-order decoupling compensator for the two-input/two-output system that is strongly coupled and then design a first-order controller for each decoupled feedback loop by using the characteristic ratio assignment method. The simulation results for the nonlinear dynamic model indicate that the proposed control configuration successfully achieves the design objectives.

  9. Adaptive nonlinear control for autonomous ground vehicles

    NASA Astrophysics Data System (ADS)

    Black, William S.

    We present the background and motivation for ground vehicle autonomy, and focus on uses for space-exploration. Using a simple design example of an autonomous ground vehicle we derive the equations of motion. After providing the mathematical background for nonlinear systems and control we present two common methods for exactly linearizing nonlinear systems, feedback linearization and backstepping. We use these in combination with three adaptive control methods: model reference adaptive control, adaptive sliding mode control, and extremum-seeking model reference adaptive control. We show the performances of each combination through several simulation results. We then consider disturbances in the system, and design nonlinear disturbance observers for both single-input-single-output and multi-input-multi-output systems. Finally, we show the performance of these observers with simulation results.

  10. Terminal Sliding Mode Tracking Controller Design for Automatic Guided Vehicle

    NASA Astrophysics Data System (ADS)

    Chen, Hongbin

    2018-03-01

    Based on sliding mode variable structure control theory, the path tracking problem of automatic guided vehicle is studied, proposed a controller design method based on the terminal sliding mode. First of all, through analyzing the characteristics of the automatic guided vehicle movement, the kinematics model is presented. Then to improve the traditional expression of terminal sliding mode, design a nonlinear sliding mode which the convergence speed is faster than the former, verified by theoretical analysis, the design of sliding mode is steady and fast convergence in the limited time. Finally combining Lyapunov method to design the tracking control law of automatic guided vehicle, the controller can make the automatic guided vehicle track the desired trajectory in the global sense as well as in finite time. The simulation results verify the correctness and effectiveness of the control law.

  11. Torque-based optimal acceleration control for electric vehicle

    NASA Astrophysics Data System (ADS)

    Lu, Dongbin; Ouyang, Minggao

    2014-03-01

    The existing research of the acceleration control mainly focuses on an optimization of the velocity trajectory with respect to a criterion formulation that weights acceleration time and fuel consumption. The minimum-fuel acceleration problem in conventional vehicle has been solved by Pontryagin's maximum principle and dynamic programming algorithm, respectively. The acceleration control with minimum energy consumption for battery electric vehicle(EV) has not been reported. In this paper, the permanent magnet synchronous motor(PMSM) is controlled by the field oriented control(FOC) method and the electric drive system for the EV(including the PMSM, the inverter and the battery) is modeled to favor over a detailed consumption map. The analytical algorithm is proposed to analyze the optimal acceleration control and the optimal torque versus speed curve in the acceleration process is obtained. Considering the acceleration time, a penalty function is introduced to realize a fast vehicle speed tracking. The optimal acceleration control is also addressed with dynamic programming(DP). This method can solve the optimal acceleration problem with precise time constraint, but it consumes a large amount of computation time. The EV used in simulation and experiment is a four-wheel hub motor drive electric vehicle. The simulation and experimental results show that the required battery energy has little difference between the acceleration control solved by analytical algorithm and that solved by DP, and is greatly reduced comparing with the constant pedal opening acceleration. The proposed analytical and DP algorithms can minimize the energy consumption in EV's acceleration process and the analytical algorithm is easy to be implemented in real-time control.

  12. Control system and method for a hybrid electric vehicle

    DOEpatents

    Tamor, Michael Alan

    2001-03-06

    Several control methods are presented for application in a hybrid electric vehicle powertrain including in various embodiments an engine, a motor/generator, a transmission coupled at an input thereof to receive torque from the engine and the motor generator coupled to augment torque provided by the engine, an energy storage device coupled to receive energy from and provide energy to the motor/generator, an engine controller (EEC) coupled to control the engine, a transmission controller (TCM) coupled to control the transmission and a vehicle system controller (VSC) adapted to control the powertrain.

  13. Entry Vehicle Control System Design for the Mars Smart Lander

    NASA Technical Reports Server (NTRS)

    Calhoun, Philip C.; Queen, Eric M.

    2002-01-01

    The NASA Langley Research Center, in cooperation with the Jet Propulsion Laboratory, participated in a preliminary design study of the Entry, Descent and Landing phase for the Mars Smart Lander Project. This concept utilizes advances in Guidance, Navigation and Control technology to significantly reduce uncertainty in the vehicle landed location on the Mars surface. A candidate entry vehicle controller based on the Reaction Control System controller for the Apollo Lunar Excursion Module digital autopilot is proposed for use in the entry vehicle attitude control. A slight modification to the phase plane controller is used to reduce jet-firing chattering while maintaining good control response for the Martian entry probe application. The controller performance is demonstrated in a six-degree-of-freedom simulation with representative aerodynamics.

  14. Self-tuning control algorithm design for vehicle adaptive cruise control system through real-time estimation of vehicle parameters and road grade

    NASA Astrophysics Data System (ADS)

    Marzbanrad, Javad; Tahbaz-zadeh Moghaddam, Iman

    2016-09-01

    The main purpose of this paper is to design a self-tuning control algorithm for an adaptive cruise control (ACC) system that can adapt its behaviour to variations of vehicle dynamics and uncertain road grade. To this aim, short-time linear quadratic form (STLQF) estimation technique is developed so as to track simultaneously the trend of the time-varying parameters of vehicle longitudinal dynamics with a small delay. These parameters are vehicle mass, road grade and aerodynamic drag-area coefficient. Next, the values of estimated parameters are used to tune the throttle and brake control inputs and to regulate the throttle/brake switching logic that governs the throttle and brake switching. The performance of the designed STLQF-based self-tuning control (STLQF-STC) algorithm for ACC system is compared with the conventional method based on fixed control structure regarding the speed/distance tracking control modes. Simulation results show that the proposed control algorithm improves the performance of throttle and brake controllers, providing more comfort while travelling, enhancing driving safety and giving a satisfactory performance in the presence of different payloads and road grade variations.

  15. On-road vehicle emission control in Beijing: past, present, and future.

    PubMed

    Wu, Ye; Wang, Renjie; Zhou, Yu; Lin, Bohong; Fu, Lixin; He, Kebin; Hao, Jiming

    2011-01-01

    Beijing, the capital of China, has experienced rapid motorization since 1990; a trend that is likely to continue. The growth in vehicles and the corresponding emissions create challenges to improving the urban air quality. In an effort to reduce the impact of vehicle emissions on urban air quality, Beijing has adopted a number of vehicle emission control strategies and policies since the mid 1990 s. These are classified into seven categories: (1) emission control on new vehicles; (2) emission control on in-use vehicles; (3) fuel quality improvements; (4) alternative-fuel and advanced vehicles; (5) economic policies; (6) public transport; and (7) temporal traffic control measures. Many have proven to be successful, such as the Euro emission standards, unleaded gasoline and low sulfur fuel, temporal traffic control measures during the Beijing Olympic Games, etc. Some, however, have been failures, such as the gasoline-to-LPG taxi retrofit program. Thanks to the emission standards for new vehicles as well as other controls, the fleet-average emission rates of CO, HC, NO(X), and PM(10) by each major vehicle category are decreasing over time. For example, gasoline cars decreased fleet-average emission factors by 12.5% for CO, 10.0% for HC, 5.8% for NO(X), and 13.0% for PM(10) annually since 1995, and such a trend is likely to continue. Total emissions for Beijing's vehicle fleet increased from 1995 to 1998. However, they show a clear and steady decrease between 1999 and 2009. In 2009, total emissions of CO, HC, NO(X), and PM(10) were 845,000 t, 121,000 t, 84,000 t, and 3700 t, respectively; with reductions of 47%, 49%, 47%, and 42%, relative to 1998. Beijing has been considered a pioneer in controlling vehicle emissions within China, similar to the role of California to the U.S. The continued rapid growth of vehicles, however, is challenging Beijing's policy-makers.

  16. Control of a high beta maneuvering reentry vehicle using dynamic inversion.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Watts, Alfred Chapman

    2005-05-01

    The design of flight control systems for high performance maneuvering reentry vehicles presents a significant challenge to the control systems designer. These vehicles typically have a much higher ballistic coefficient than crewed vehicles like as the Space Shuttle or proposed crew return vehicles such as the X-38. Moreover, the missions of high performance vehicles usually require a steeper reentry flight path angle, followed by a pull-out into level flight. These vehicles then must transit the entire atmosphere and robustly perform the maneuvers required for the mission. The vehicles must also be flown with small static margins in order to performmore » the required maneuvers, which can result in highly nonlinear aerodynamic characteristics that frequently transition from being aerodynamically stable to unstable as angle of attack increases. The control system design technique of dynamic inversion has been applied successfully to both high performance aircraft and low beta reentry vehicles. The objective of this study was to explore the application of this technique to high performance maneuvering reentry vehicles, including the basic derivation of the dynamic inversion technique, followed by the extension of that technique to the use of tabular trim aerodynamic models in the controller. The dynamic inversion equations are developed for high performance vehicles and augmented to allow the selection of a desired response for the control system. A six degree of freedom simulation is used to evaluate the performance of the dynamic inversion approach, and results for both nominal and off nominal aerodynamic characteristics are presented.« less

  17. Design and experimental validation of linear and nonlinear vehicle steering control strategies

    NASA Astrophysics Data System (ADS)

    Menhour, Lghani; Lechner, Daniel; Charara, Ali

    2012-06-01

    This paper proposes the design of three control laws dedicated to vehicle steering control, two based on robust linear control strategies and one based on nonlinear control strategies, and presents a comparison between them. The two robust linear control laws (indirect and direct methods) are built around M linear bicycle models, each of these control laws is composed of two M proportional integral derivative (PID) controllers: one M PID controller to control the lateral deviation and the other M PID controller to control the vehicle yaw angle. The indirect control law method is designed using an oscillation method and a nonlinear optimisation subject to H ∞ constraint. The direct control law method is designed using a linear matrix inequality optimisation in order to achieve H ∞ performances. The nonlinear control method used for the correction of the lateral deviation is based on a continuous first-order sliding-mode controller. The different methods are designed using a linear bicycle vehicle model with variant parameters, but the aim is to simulate the nonlinear vehicle behaviour under high dynamic demands with a four-wheel vehicle model. These steering vehicle controls are validated experimentally using the data acquired using a laboratory vehicle, Peugeot 307, developed by National Institute for Transport and Safety Research - Department of Accident Mechanism Analysis Laboratory's (INRETS-MA) and their performance results are compared. Moreover, an unknown input sliding-mode observer is introduced to estimate the road bank angle.

  18. Robust on-off pulse control of flexible space vehicles

    NASA Technical Reports Server (NTRS)

    Wie, Bong; Sinha, Ravi

    1993-01-01

    The on-off reaction jet control system is often used for attitude and orbital maneuvering of various spacecraft. Future space vehicles such as the orbital transfer vehicles, orbital maneuvering vehicles, and space station will extensively use reaction jets for orbital maneuvering and attitude stabilization. The proposed robust fuel- and time-optimal control algorithm is used for a three-mass spacing model of flexible spacecraft. A fuel-efficient on-off control logic is developed for robust rest-to-rest maneuver of a flexible vehicle with minimum excitation of structural modes. The first part of this report is concerned with the problem of selecting a proper pair of jets for practical trade-offs among the maneuvering time, fuel consumption, structural mode excitation, and performance robustness. A time-optimal control problem subject to parameter robustness constraints is formulated and solved. The second part of this report deals with obtaining parameter insensitive fuel- and time- optimal control inputs by solving a constrained optimization problem subject to robustness constraints. It is shown that sensitivity to modeling errors can be significantly reduced by the proposed, robustified open-loop control approach. The final part of this report deals with sliding mode control design for uncertain flexible structures. The benchmark problem of a flexible structure is used as an example for the feedback sliding mode controller design with bounded control inputs and robustness to parameter variations is investigated.

  19. A hybrid approach to modeling and control of vehicle height for electronically controlled air suspension

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoqiang; Cai, Yingfeng; Wang, Shaohua; Liu, Yanling; Chen, Long

    2016-01-01

    The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical (MLD) modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller (HMPC) is tuned based on online mixed-integer quadratic optimization (MIQP). Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology (MPT), thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties.

  20. Nonlinear stability and control of gliding vehicles

    NASA Astrophysics Data System (ADS)

    Bhatta, Pradeep

    In this thesis we use nonlinear systems analysis to study dynamics and design control solutions for vehicles subject to hydrodynamic or aerodynamic forcing. Application of energy-based methods for such vehicles is challenging due to the presence of energy-conserving lift and side forces. We study how the lift force determines the geometric structure of vehicle dynamics. A Hamiltonian formulation of the integrable phugoid-mode equations provides a Lyapunov function candidate, which is used throughout the thesis for deriving equilibrium stability results and designing stabilizing control laws. A strong motivation for our work is the emergence of underwater gliders as an important observation platform for oceanography. Underwater gliders rely on buoyancy regulation and internal mass redistribution for motion control. These vehicles are attractive because they are designed to operate autonomously and continuously for several weeks. The results presented in this thesis contribute toward the development of systematic control design procedures for extending the range of provably stable maneuvers of the underwater glider. As the first major contribution we derive conditions for nonlinear stability of longitudinal steady gliding motions using singular perturbation theory. Stability is proved using a composite Lyapunov function, composed of individual Lyapunov functions that prove stability of rotational and translational subsystem equilibria. We use the composite Lyapunov function to design control laws for stabilizing desired relative equilibria in different actuation configurations for the underwater glider. We propose an approximate trajectory tracking method for an aircraft model. Our method uses exponential stability results of controllable steady gliding motions, derived by interpreting the aircraft dynamics as an interconnected system of rotational and translational subsystems. We prove bounded position error for tracking prescribed, straight-line trajectories, and

  1. Signal processing and control challenges for smart vehicles

    NASA Astrophysics Data System (ADS)

    Zhang, Hui; Braun, Simon G.

    2017-03-01

    Smart phones have changed not only the mobile phone market but also our society during the past few years. Could the next potential intelligent device may be the vehicle? Judging by the visibility, in all media, of the numerous attempts to develop autonomous vehicles, this is certainly one of the logical outcomes. Smart vehicles would be equipped with an advanced operating system such that the vehicles could communicate with others, optimize the operation to reduce fuel consumption and emissions, enhance safety, or even become self-driving. These combined new features of vehicles require instrumentation and hardware developments, fast signal processing/fusion, decision making and online optimization. Meanwhile, the inevitable increasing system complexity would certainly challenges the control unit design.

  2. Aerodynamic flight control to increase payload capability of future launch vehicles

    NASA Technical Reports Server (NTRS)

    Cochran, John E., Jr.

    1995-01-01

    The development of new launch vehicles will require that designers use innovative approaches to achieve greater performance in terms of pay load capability. The objective of the work performed under this delivery order was to provide technical assistance to the Contract Officer's Technical Representative (COTR) in the development of ideas and concepts for increasing the payload capability of launch vehicles by incorporating aerodynamic controls. Although aerodynamic controls, such as moveable fins, are currently used on relatively small missiles, the evolution of large launch vehicles has been moving away from aerodynamic control. The COTR reasoned that a closer investigation of the use of aerodynamic controls on large vehicles was warranted.

  3. The Vehicle Control Systems Branch at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Barret, Chris

    1990-01-01

    This paper outlines the responsibility of the Vehicle Control Systems Branch at the Marshall Space Flight Center (MSFC) to analyze, evaluate, define, design, verify, and specify requirements for advanced launch vehicles and related space projects, and to conduct research in advanced flight control concepts. Attention is given to branch responsibilities which include Shuttle-C, Shuttle-C Block II, Shuttle-Z, lunar cargo launch vehicles, Mars cargo launch vehicles, orbital maneuvering vehicle, automatic docking, tethered satellite, aeroassisted flight experiment, and solid rocket booster parachute recovery system design.

  4. New techniques to control salinity-wastewater reuse interactions in golf courses of the Mediterranean regions

    NASA Astrophysics Data System (ADS)

    Beltrao, J.; Costa, M.; Rosado, V.; Gamito, P.; Santos, R.; Khaydarova, V.

    2003-04-01

    Due to the lack water around the Mediterranean regions, potable water luxurious uses - as in golf courses - are increasingly contested. In order to solve this problem, non conventional water resources (effluent, gray, recycled, reclaimed, brackish), like treated wastewater, for irrigation gained increasing role in the planning and development of additional water supplies in golf courses. In most cases, the intense use of effluent for irrigation attracted public awareness in respect of contaminating pathogens and heavy metals. The contaminating effect of salinity in soil and underground water is very often neglected. The objective of this work is to present the conventional techniques to control salinity of treated wastewater and to present some results on new clean techniques to solve this problem, in the framework of the INCO-COPERNICUS project (no. IC-15CT98-0105) "Adaptation of Efficient Water Use Criteria in Marginal Regions of Europe and Middle Asia with Scarce Sources Subject to Environmental Control, Climate Change and Socio-Economic Development" and of the INCO-DC project (no. IC18-CT98-0266) "Control of Salination and Combating Desertification Effects in the Mediterranean Region. Phase II". Saline water is the most common irrigation water in arid climates. Moreover, for each region treated wastewater is always more saline than tap water, and therefore, when treated wastewater is reused in golf courses, more salinity problems occur. Conventional techniques to combat the salination process in golf courses can be characterized by four generations: 1) Problem of root zone salination by soil leaching - two options can occur - when there is an impermeable layer, salts will be concentrated above this layer; on the other hand, when there is no impermeable layer, aquifers contamination can be observed; 2) Use of subsurface trickle irrigation - economy of water, and therefore less additional salts; however the problem of groundwater contamination due to natural rain

  5. Hypersonic Vehicle Propulsion System Control Model Development Roadmap and Activities

    NASA Technical Reports Server (NTRS)

    Stueber, Thomas J.; Le, Dzu K.; Vrnak, Daniel R.

    2009-01-01

    The NASA Fundamental Aeronautics Program Hypersonic project is directed towards fundamental research for two classes of hypersonic vehicles: highly reliable reusable launch systems (HRRLS) and high-mass Mars entry systems (HMMES). The objective of the hypersonic guidance, navigation, and control (GN&C) discipline team is to develop advanced guidance and control algorithms to enable efficient and effective operation of these challenging vehicles. The ongoing work at the NASA Glenn Research Center supports the hypersonic GN&C effort in developing tools to aid the design of advanced control algorithms that specifically address the propulsion system of the HRRLSclass vehicles. These tools are being developed in conjunction with complementary research and development activities in hypersonic propulsion at Glenn and elsewhere. This report is focused on obtaining control-relevant dynamic models of an HRRLS-type hypersonic vehicle propulsion system.

  6. Improvement in vehicle agility and stability by G-Vectoring control

    NASA Astrophysics Data System (ADS)

    Yamakado, Makoto; Takahashi, Jyunya; Saito, Shinjiro; Yokoyama, Atsushi; Abe, Masato

    2010-12-01

    We extracted a trade-off strategy between longitudinal traction/braking force and cornering force by using jerk information through observing an expert driver's voluntary braking and turning action. Using the expert driver's strategy, we developed a new control concept, called 'G-Vectoring control', which is an automatic longitudinal acceleration control (No DYC) in accordance with the vehicle's lateral jerk caused by the driver's steering manoeuvres. With the control, the direction of synthetic acceleration (G) changes seamlessly (i.e. vectoring). The improvements in vehicle agility and stability were evaluated by theoretical analysis and through computer simulation. We then introduced a 'G-Vectoring' equipped test vehicle realised by brake-by-wire technology and executed a detailed examination on a test track. We have confirmed that the vehicle motion in view of both handling and ride quality has improved dramatically.

  7. Wireless Control of Miniaturized Mobile Vehicle for Indoor Surveillance

    NASA Astrophysics Data System (ADS)

    Taha Saquib, Syed M.; Hameed, Sarmad; Usman Ali, Syed M.; Jafri, Raza; Amin, Imran

    2013-12-01

    This work is based upon electronic automation and Smart Control techniques, which constitute the basis of Control Area Network (CAN) and Personal Area Network (PAN). Bluetooth technology has been interfaced with a programmable controller to provide multi-dimensional vehicle control. A network is proposed which contains a remote, mobile host controller and an android operating system based mobile set (Client). The client communicates with a host controller through a Bluetooth device. The system incorporates duplex communication after successful confirmation between the host and the client; the android based mobile unit controls the vehicle through the Bluetooth module.

  8. An Entry Flight Controls Analysis for a Reusable Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Calhoun, Philip

    2000-01-01

    The NASA Langley Research Center has been performing studies to address the feasibility of various single-stage to orbit concepts for use by NASA and the commercial launch industry to provide a lower cost access to space. Some work on the conceptual design of a typical lifting body concept vehicle, designated VentureStar(sup TM) has been conducted in cooperation with the Lockheed Martin Skunk Works. This paper will address the results of a preliminary flight controls assessment of this vehicle concept during the atmospheric entry phase of flight. The work includes control analysis from hypersonic flight at the atmospheric entry through supersonic speeds to final approach and landing at subsonic conditions. The requirements of the flight control effectors are determined over the full range of entry vehicle Mach number conditions. The analysis was performed for a typical maximum crossrange entry trajectory utilizing angle of attack to limit entry heating and providing for energy management, and bank angle to modulation of the lift vector to provide downrange and crossrange capability to fly the vehicle to a specified landing site. Sensitivity of the vehicle open and closed loop characteristics to CG location, control surface mixing strategy and wind gusts are included in the results. An alternative control surface mixing strategy utilizing a reverse aileron technique demonstrated a significant reduction in RCS torque and fuel required to perform bank maneuvers during entry. The results of the control analysis revealed challenges for an early vehicle configuration in the areas of hypersonic pitch trim and subsonic longitudinal controllability.

  9. Simulation and Flight Control of an Aeroelastic Fixed Wing Micro Aerial Vehicle

    NASA Technical Reports Server (NTRS)

    Waszak, Martin; Davidson, John B.; Ifju, Peter G.

    2002-01-01

    Micro aerial vehicles have been the subject of continued interest and development over the last several years. The majority of current vehicle concepts rely on rigid fixed wings or rotors. An alternate design based on an aeroelastic membrane wing has also been developed that exhibits desired characteristics in flight test demonstrations, competition, and in prior aerodynamics studies. This paper presents a simulation model and an assessment of flight control characteristics of the vehicle. Linear state space models of the vehicle associated with typical trimmed level flight conditions and which are suitable for control system design are presented as well. The simulation is used as the basis for the design of a measurement based nonlinear dynamic inversion control system and outer loop guidance system. The vehicle/controller system is the subject of ongoing investigations of autonomous and collaborative control schemes. The results indicate that the design represents a good basis for further development of the micro aerial vehicle for autonomous and collaborative controls research.

  10. Reusable Launch Vehicle Control In Multiple Time Scale Sliding Modes

    NASA Technical Reports Server (NTRS)

    Shtessel, Yuri; Hall, Charles; Jackson, Mark

    2000-01-01

    A reusable launch vehicle control problem during ascent is addressed via multiple-time scaled continuous sliding mode control. The proposed sliding mode controller utilizes a two-loop structure and provides robust, de-coupled tracking of both orientation angle command profiles and angular rate command profiles in the presence of bounded external disturbances and plant uncertainties. Sliding mode control causes the angular rate and orientation angle tracking error dynamics to be constrained to linear, de-coupled, homogeneous, and vector valued differential equations with desired eigenvalues placement. Overall stability of a two-loop control system is addressed. An optimal control allocation algorithm is designed that allocates torque commands into end-effector deflection commands, which are executed by the actuators. The dual-time scale sliding mode controller was designed for the X-33 technology demonstration sub-orbital launch vehicle in the launch mode. Simulation results show that the designed controller provides robust, accurate, de-coupled tracking of the orientation angle command profiles in presence of external disturbances and vehicle inertia uncertainties. This is a significant advancement in performance over that achieved with linear, gain scheduled control systems currently being used for launch vehicles.

  11. Neuro-fuzzy controller to navigate an unmanned vehicle.

    PubMed

    Selma, Boumediene; Chouraqui, Samira

    2013-12-01

    A Neuro-fuzzy control method for an Unmanned Vehicle (UV) simulation is described. The objective is guiding an autonomous vehicle to a desired destination along a desired path in an environment characterized by a terrain and a set of distinct objects, such as obstacles like donkey traffic lights and cars circulating in the trajectory. The autonomous navigate ability and road following precision are mainly influenced by its control strategy and real-time control performance. Fuzzy Logic Controller can very well describe the desired system behavior with simple "if-then" relations owing the designer to derive "if-then" rules manually by trial and error. On the other hand, Neural Networks perform function approximation of a system but cannot interpret the solution obtained neither check if its solution is plausible. The two approaches are complementary. Combining them, Neural Networks will allow learning capability while Fuzzy-Logic will bring knowledge representation (Neuro-Fuzzy). In this paper, an artificial neural network fuzzy inference system (ANFIS) controller is described and implemented to navigate the autonomous vehicle. Results show several improvements in the control system adjusted by neuro-fuzzy techniques in comparison to the previous methods like Artificial Neural Network (ANN).

  12. Fault-tolerant control of electric vehicles with in-wheel motors using actuator-grouping sliding mode controllers

    NASA Astrophysics Data System (ADS)

    Li, Boyuan; Du, Haiping; Li, Weihua

    2016-05-01

    Although electric vehicles with in-wheel motors have been regarded as one of the promising vehicle architectures in recent years, the probability of in-wheel motor fault is still a crucial issue due to the system complexity and large number of control actuators. In this study, a modified sliding mode control (SMC) is applied to achieve fault-tolerant control of electric vehicles with four-wheel-independent-steering (4WIS) and four-wheel-independent-driving (4WID). Unlike in traditional SMC, in this approach the steering geometry is re-arranged according to the location of faulty wheels in the modified SMC. Three SMC control laws for longitudinal velocity control, lateral velocity control and yaw rate control are designed based on specific vehicle motion scenarios. In addition the actuator-grouping SMC method is proposed so that driving actuators are grouped and each group of actuators can be used to achieve the specific control target, which avoids the strong coupling effect between each control target. Simulation results prove that the proposed modified SMC can achieve good vehicle dynamics control performance in normal driving and large steering angle turning scenarios. In addition, the proposed actuator-grouping SMC can solve the coupling effect of different control targets and the control performance is improved.

  13. Osmoregulation and muscle water control in vitro facing salinity stress of the Amazon fish Oscar Astronotus ocellatus (Cichlidae)

    USGS Publications Warehouse

    Gutierre, Silvia M. M.; Schulte, Jessica M.; Schofield, Pam; Prodocimo, Viviane

    2017-01-01

    Specimens of Oscar Astronotus ocellatus from a fish farm were abruptly submitted to salt stress of 14 ppt and 20 ppt, for 3 and 8 h to determine their plasma osmolality. Muscle wet body mass change in vitro was analyzed from control freshwater animals. Fish in 14 ppt presented no osmolality distress even after 8 h. In 20 ppt, a slight increase (10%) in plasma osmolality was observed for both times of exposure when compared to control fish. Muscle slices submitted in vitro to hyper-osmotic saline displayed decreased body mass after 75 min, and slices submitted to hypo-osmotic saline displayed increased body mass after 45 min when compared to control (isosmotic saline). These results reinforce A. ocellatus’s euryhalinity. The fish were able to regulate its internal medium and tolerate 14 ppt, but presented an intense osmotic challenge and low muscle hydration control when facing salinities of 20 ppt.

  14. Run-off-road and recovery - state estimation and vehicle control strategies

    NASA Astrophysics Data System (ADS)

    Freeman, P.; Wagner, J.; Alexander, K.

    2016-09-01

    Despite many advances in vehicle safety technology, traffic fatalities remain a devastating burden on society. With over two-thirds of all fatal single-vehicle crashes occurring off the roadway, run-off-road (ROR) crashes have become the focus of much roadway safety research. Current countermeasures, including roadway infrastructure modifications and some on-board vehicle safety systems, remain limited in their approach as they do not directly address the critical factor of driver behaviour. It has been shown that ROR crashes are often the result of poor driver performance leading up to the crash. In this study, the performance of two control algorithms, sliding control and linear quadratic control, was investigated for use in an autonomous ROR vehicle recovery system. The two controllers were simulated amongst a variety of ROR conditions where typical driver performance was inadequate to safely operate the vehicle. The sliding controller recovered the fastest within the nominal conditions but exhibited large variability in performance amongst the more extreme ROR scenarios. Despite some small sacrifices in lateral error and yaw rate, the linear quadratic controller demonstrated a higher level of consistency and stability amongst the various conditions examined. Overall, the linear quadratic controller recovered the vehicle 25% faster than the sliding controller while using 70% less steering, which combined with its robust performance, indicates its high potential as an autonomous ROR countermeasure.

  15. Comprehensive modeling and control of flexible flapping wing micro air vehicles

    NASA Astrophysics Data System (ADS)

    Nogar, Stephen Michael

    Flapping wing micro air vehicles hold significant promise due to the potential for improved aerodynamic efficiency, enhanced maneuverability and hover capability compared to fixed and rotary configurations. However, significant technical challenges exist to due the lightweight, highly integrated nature of the vehicle and coupling between the actuators, flexible wings and control system. Experimental and high fidelity analysis has demonstrated that aeroelastic effects can change the effective kinematics of the wing, reducing vehicle stability. However, many control studies for flapping wing vehicles do not consider these effects, and instead validate the control strategy with simple assumptions, including rigid wings, quasi-steady aerodynamics and no consideration of actuator dynamics. A control evaluation model that includes aeroelastic effects and actuator dynamics is developed. The structural model accounts for geometrically nonlinear behavior using an implicit condensation technique and the aerodynamic loads are found using a time accurate approach that includes quasi-steady, rotational, added mass and unsteady effects. Empirically based parameters in the model are fit using data obtained from a higher fidelity solver. The aeroelastic model and its ingredients are compared to experiments and computations using models of higher fidelity, and indicate reasonable agreement. The developed control evaluation model is implemented in a previously published, baseline controller that maintains stability using an asymmetric wingbeat, known as split-cycle, along with changing the flapping frequency and wing bias. The model-based controller determines the control inputs using a cycle-averaged, linear control design model, which assumes a rigid wing and no actuator dynamics. The introduction of unaccounted for dynamics significantly degrades the ability of the controller to track a reference trajectory, and in some cases destabilizes the vehicle. This demonstrates the

  16. Intelligent Hybrid Vehicle Power Control. Part 2. Online Intelligent Energy Management

    DTIC Science & Technology

    2012-06-30

    IEC_HEV for vehicle energy optimization. IEC_HEV, the Figure 1. Power Split HEV configuration into VSC 5 online energy control is a component...in the Vehicle System Controller ( VSC ). The VSC for this configuration must manage the powertrain control in order to maintain a proper level of...charge in the battery. However, since two power sources are available to propel the vehicle, the VSC in this configuration has the additional

  17. Stability and optimised H∞ control of tripped and untripped vehicle rollover

    NASA Astrophysics Data System (ADS)

    Jin, Zhilin; Zhang, Lei; Zhang, Jiale; Khajepour, Amir

    2016-10-01

    Vehicle rollover is a serious traffic accident. In order to accurately evaluate the possibility of untripped and some special tripped vehicle rollovers, and to prevent vehicle rollover under unpredictable variations of parameters and harsh driving conditions, a new rollover index and an anti-roll control strategy are proposed in this paper. Taking deflections of steering and suspension induced by the roll at the axles into consideration, a six degrees of freedom dynamic model is established, including lateral, yaw, roll, and vertical motions of sprung and unsprung masses. From the vehicle dynamics theory, a new rollover index is developed to predict vehicle rollover risk under both untripped and special tripped situations. This new rollover index is validated by Carsim simulations. In addition, an H-infinity controller with electro hydraulic brake system is optimised by genetic algorithm to improve the anti-rollover performance of the vehicle. The stability and robustness of the active rollover prevention control system are analysed by some numerical simulations. The results show that the control system can improve the critical speed of vehicle rollover obviously, and has a good robustness for variations in the number of passengers and longitude position of the centre of gravity.

  18. Electric vehicle motors and controllers

    NASA Technical Reports Server (NTRS)

    Secunde, R. R.

    1981-01-01

    Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

  19. Electric vehicle motors and controllers

    NASA Astrophysics Data System (ADS)

    Secunde, R. R.

    Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

  20. An RFID-based intelligent vehicle speed controller using active traffic signals.

    PubMed

    Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C; de Pedro, Teresa

    2010-01-01

    These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver's attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results.

  1. An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

    PubMed Central

    Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C.; de Pedro, Teresa

    2010-01-01

    These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results. PMID:22219692

  2. Reentry Vehicle Flight Controls Design Guidelines: Dynamic Inversion

    NASA Technical Reports Server (NTRS)

    Ito, Daigoro; Georgie, Jennifer; Valasek, John; Ward, Donald T.

    2002-01-01

    This report addresses issues in developing a flight control design for vehicles operating across a broad flight regime and with highly nonlinear physical descriptions of motion. Specifically it addresses the need for reentry vehicles that could operate through reentry from space to controlled touchdown on Earth. The latter part of controlled descent is achieved by parachute or paraglider - or by all automatic or a human-controlled landing similar to that of the Orbiter. Since this report addresses the specific needs of human-carrying (not necessarily piloted) reentry vehicles, it deals with highly nonlinear equations of motion, and then-generated control systems must be robust across a very wide range of physics. Thus, this report deals almost exclusively with some form of dynamic inversion (DI). Two vital aspects of control theory - noninteracting control laws and the transformation of nonlinear systems into equivalent linear systems - are embodied in DI. Though there is no doubt that the mathematical tools and underlying theory are widely available, there are open issues as to the practicality of using DI as the only or primary design approach for reentry articles. This report provides a set of guidelines that can be used to determine the practical usefulness of the technique.

  3. Integrated Vehicle Ground Vibration Testing in Support of NASA Launch Vehicle Loads and Controls Analysis

    NASA Technical Reports Server (NTRS)

    Tuma, Margaret L.; Davis, Susan R.; Askins, Bruce R.; Salyer, Blaine H.

    2008-01-01

    The National Aeronautics and Space Administration (NASA) Ares Projects Office (APO) is continuing to make progress toward the final design of the Ares I crew launch vehicle and Ares V cargo launch vehicle. Ares I and V will form the space launch capabilities necessary to fulfill NASA's exploration strategy of sending human beings to the Moon, Mars, and beyond. As with all new space vehicles there will be a number of tests to ensure the design can be Human Rated. One of these is the Integrated Vehicle Ground Vibration Test (IVGVT) that will be measuring responses of the Ares I as a system. All structural systems possess a basic set of physical characteristics unique to that system. These unique characteristics include items such as mass distribution, frequency and damping. When specified, they allow engineers to understand and predict how a structural system like the Ares I launch vehicle behaves under given loading conditions. These physical properties of launch vehicles may be predicted by analysis or measured through certain types of tests. Generally, these properties are predicted by analysis during the design phase of a launch vehicle and then verified through testing before the vehicle is Human Rated. The IVGVT is intended to measure by test the fundamental dynamic characteristics of Ares I during various phases of operational/flight. This testing includes excitations of the vehicle in lateral, longitudinal, and torsional directions at vehicle configurations representing different trajectory points. During the series of tests, properties such as natural frequencies, mode shapes, and transfer functions are measured directly. These data will then be used to calibrate loads and Guidance, Navigation, and Controls (GN&C) analysis models for verifying analyses of Ares I. NASA launch vehicles from Saturn to Shuttle have undergone Ground Vibration Tests (GVTs) leading to successful launch vehicles. A GVT was not performed on the unmanned Delta III. This vehicle was

  4. Experiments in teleoperator and autonomous control of space robotic vehicles

    NASA Technical Reports Server (NTRS)

    Alexander, Harold L.

    1991-01-01

    A program of research embracing teleoperator and automatic navigational control of freely flying satellite robots is presented. Current research goals include: (1) developing visual operator interfaces for improved vehicle teleoperation; (2) determining the effects of different visual interface system designs on operator performance; and (3) achieving autonomous vision-based vehicle navigation and control. This research program combines virtual-environment teleoperation studies and neutral-buoyancy experiments using a space-robot simulator vehicle currently under development. Visual-interface design options under investigation include monoscopic versus stereoscopic displays and cameras, helmet-mounted versus panel-mounted display monitors, head-tracking versus fixed or manually steerable remote cameras, and the provision of vehicle-fixed visual cues, or markers, in the remote scene for improved sensing of vehicle position, orientation, and motion.

  5. Prediction of forces and moments for flight vehicle control effectors: Workplan

    NASA Technical Reports Server (NTRS)

    Maughmer, Mark D.

    1989-01-01

    Two research activities directed at hypersonic vehicle configurations are currently underway. The first involves the validation of a number of classical local surface inclination methods commonly employed in preliminary design studies of hypersonic flight vehicles. Unlike studies aimed at validating such methods for predicting overall vehicle aerodynamics, this effort emphasizes validating the prediction of forces and moments for flight control studies. Specifically, several vehicle configurations for which experimental or flight-test data are available are being examined. By comparing the theoretical predictions with these data, the strengths and weaknesses of the local surface inclination methods can be ascertained and possible improvements suggested. The second research effort, of significance to control during take-off and landing of most proposed hypersonic vehicle configurations, is aimed at determining the change due to ground effect in control effectiveness of highly swept delta planforms. Central to this research is the development of a vortex-lattice computer program which incorporates an unforced trailing vortex sheet and an image ground plane. With this program, the change in pitching moment of the basic vehicle due to ground proximity, and whether or not there is sufficient control power available to trim, can be determined. In addition to the current work, two different research directions are suggested for future study. The first is aimed at developing an interactive computer program to assist the flight controls engineer in determining the forces and moments generated by different types of control effectors that might be used on hypersonic vehicles. The first phase of this work would deal in the subsonic portion of the flight envelope, while later efforts would explore the supersonic/hypersonic flight regimes. The second proposed research direction would explore methods for determining the aerodynamic trim drag of a generic hypersonic flight vehicle

  6. The Lateral Tracking Control for the Intelligent Vehicle Based on Adaptive PID Neural Network.

    PubMed

    Han, Gaining; Fu, Weiping; Wang, Wen; Wu, Zongsheng

    2017-05-30

    The intelligent vehicle is a complicated nonlinear system, and the design of a path tracking controller is one of the key technologies in intelligent vehicle research. This paper mainly designs a lateral control dynamic model of the intelligent vehicle, which is used for lateral tracking control. Firstly, the vehicle dynamics model (i.e., transfer function) is established according to the vehicle parameters. Secondly, according to the vehicle steering control system and the CARMA (Controlled Auto-Regression and Moving-Average) model, a second-order control system model is built. Using forgetting factor recursive least square estimation (FFRLS), the system parameters are identified. Finally, a neural network PID (Proportion Integral Derivative) controller is established for lateral path tracking control based on the vehicle model and the steering system model. Experimental simulation results show that the proposed model and algorithm have the high real-time and robustness in path tracing control. This provides a certain theoretical basis for intelligent vehicle autonomous navigation tracking control, and lays the foundation for the vertical and lateral coupling control.

  7. The Lateral Tracking Control for the Intelligent Vehicle Based on Adaptive PID Neural Network

    PubMed Central

    Han, Gaining; Fu, Weiping; Wang, Wen; Wu, Zongsheng

    2017-01-01

    The intelligent vehicle is a complicated nonlinear system, and the design of a path tracking controller is one of the key technologies in intelligent vehicle research. This paper mainly designs a lateral control dynamic model of the intelligent vehicle, which is used for lateral tracking control. Firstly, the vehicle dynamics model (i.e., transfer function) is established according to the vehicle parameters. Secondly, according to the vehicle steering control system and the CARMA (Controlled Auto-Regression and Moving-Average) model, a second-order control system model is built. Using forgetting factor recursive least square estimation (FFRLS), the system parameters are identified. Finally, a neural network PID (Proportion Integral Derivative) controller is established for lateral path tracking control based on the vehicle model and the steering system model. Experimental simulation results show that the proposed model and algorithm have the high real-time and robustness in path tracing control. This provides a certain theoretical basis for intelligent vehicle autonomous navigation tracking control, and lays the foundation for the vertical and lateral coupling control. PMID:28556817

  8. Stochastic optimal preview control of a vehicle suspension

    NASA Astrophysics Data System (ADS)

    Marzbanrad, Javad; Ahmadi, Goodarz; Zohoor, Hassan; Hojjat, Yousef

    2004-08-01

    Stochastic optimal control of a vehicle suspension on a random road is studied. The road roughness height is modelled as a filtered white noise stochastic process and a four-degree-of-freedom half-car model is used in the analysis. It is assumed that a sensor is mounted in the front bumper that measures the road irregularity at some distances in the front of the vehicle. Two other sensors also measure relative velocities of the vehicle body with respect to the unsprung masses in the vehicle suspension spaces. All measurements are assumed to be conducted in a noisy environment. The state variables of the vehicle system are estimated using a method similar to the Kalman filter. The suspension system is optimized by minimizing the performance index containing the mean-square values of body accelerations (including effects of heave and pitch), tire deflections and front and rear suspension rattle spaces. The effect of delay between front and rear wheels is included in the analysis. For stochastic active control with and without preview, the suspension performance and the power demand are evaluated and compared with those of the passive system. The results show that the inclusion of time delay between the front and rear axles and the preview information measured by the sensor mounted on the vehicle improves all aspects of the suspension performance, while reducing the energy consumption.

  9. Advanced Guidance and Control Project for Reusable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Hanson, John M.

    2000-01-01

    The goals of this project are to significantly reduce the time and cost associated with guidance and control design for reusable launch vehicles, and to increase their safety and reliability. Success will lead to reduced cycle times during vehicle design and to reduced costs associated with flying to new orbits, with new payloads, and with modified vehicles. Success will also lead to more robustness to unforeseen circumstances in flight thereby enhancing safety and reducing risk. There are many guidance and control methods available that hold some promise for improvement in the desired areas. Investigators are developing a representative set of independent guidance and control methods for this project. These methods are being incorporated into a high-fidelity off is being conducted across a broad range of flight requirements. The guidance and control methods that perform the best will have demonstrated the desired qualities.

  10. Yaw rate control of an air bearing vehicle

    NASA Technical Reports Server (NTRS)

    Walcott, Bruce L.

    1989-01-01

    The results of a 6 week project which focused on the problem of controlling the yaw (rotational) rate the air bearing vehicle used on NASA's flat floor facility are summarized. Contained within is a listing of the equipment available for task completion and an evaluation of the suitability of this equipment. The identification (modeling) process of the air bearing vehicle is detailed as well as the subsequent closed-loop control strategy. The effectiveness of the solution is discussed and further recommendations are included.

  11. Crew Exploration Vehicle Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Cross, Cynthia D.; Carrasquillo, Robyn; Rains, George Edward

    2011-01-01

    The Orion Crew Exploration Vehicle (CEV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. The CEV is currently being developed to transport the crew safely from the Earth to the Moon and back again. This year, the vehicle focused on building the Orion Flight Test 1 (OFT1) vehicle to be launched in 2013. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the components which are on OFT1 which includes pressure control and active thermal control systems, is progressing through the design stage into manufacturing. Additional development work was done to keep the remaining component progressing towards implementation. This paper covers the Orion ECLS development from April 2010 to April 2011.

  12. Semi-active sliding mode control of vehicle suspension with magneto-rheological damper

    NASA Astrophysics Data System (ADS)

    Zhang, Hailong; Wang, Enrong; Zhang, Ning; Min, Fuhong; Subash, Rakheja; Su, Chunyi

    2015-01-01

    The vehicle semi-active suspension with magneto-rheological damper(MRD) has been a hot topic since this decade, in which the robust control synthesis considering load variation is a challenging task. In this paper, a new semi-active controller based upon the inverse model and sliding mode control (SMC) strategies is proposed for the quarter-vehicle suspension with the magneto-rheological (MR) damper, wherein an ideal skyhook suspension is employed as the control reference model and the vehicle sprung mass is considered as an uncertain parameter. According to the asymptotical stability of SMC, the dynamic errors between the plant and reference systems are used to derive the control damping force acquired by the MR quarter-vehicle suspension system. The proposed modified Bouc-wen hysteretic force-velocity ( F- v) model and its inverse model of MR damper, as well as the proposed continuous modulation (CM) filtering algorithm without phase shift are employed to convert the control damping force into the direct drive current of the MR damper. Moreover, the proposed semi-active sliding mode controller (SSMC)-based MR quarter-vehicle suspension is systematically evaluated through comparing the time and frequency domain responses of the sprung and unsprung mass displacement accelerations, suspension travel and the tire dynamic force with those of the passive quarter-vehicle suspension, under three kinds of varied amplitude harmonic, rounded pulse and real-road measured random excitations. The evaluation results illustrate that the proposed SSMC can greatly suppress the vehicle suspension vibration due to uncertainty of the load, and thus improve the ride comfort and handling safety. The study establishes a solid theoretical foundation as the universal control scheme for the adaptive semi-active control of the MR full-vehicle suspension decoupled into four MR quarter-vehicle sub-suspension systems.

  13. Climate Control Load Reduction Strategies for Electric Drive Vehicles in Warm Weather

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jeffers, M. A.; Chaney, L.; Rugh, J. P.

    Passenger compartment climate control is one of the largest auxiliary loads on a vehicle. Like conventional vehicles, electric vehicles (EVs) require climate control to maintain occupant comfort and safety, but cabin heating and air conditioning have a negative impact on driving range for all electric vehicles. Range reduction caused by climate control and other factors is a barrier to widespread adoption of EVs. Reducing the thermal loads on the climate control system will extend driving range, thereby reducing consumer range anxiety and increasing the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have investigated strategies for vehiclemore » climate control load reduction, with special attention toward EVs. Outdoor vehicle thermal testing was conducted on two 2012 Ford Focus Electric vehicles to evaluate thermal management strategies for warm weather, including solar load reduction and cabin pre-ventilation. An advanced thermal test manikin was used to assess a zonal approach to climate control. In addition, vehicle thermal analysis was used to support testing by exploring thermal load reduction strategies, evaluating occupant thermal comfort, and calculating EV range impacts. Through stationary cooling tests and vehicle simulations, a zonal cooling configuration demonstrated range improvement of 6%-15%, depending on the drive cycle. A combined cooling configuration that incorporated thermal load reduction and zonal cooling strategies showed up to 33% improvement in EV range.« less

  14. Feasibility of advanced vehicle control systems for transit buses

    DOT National Transportation Integrated Search

    1997-01-01

    In the course of developing automated vehicle-roadway systems, opportunities to deploy vehicle control systems at intermediate stages of development may emerge. Some of these systems may provide a significant efficiency or safety enhancement to exist...

  15. Effects of the Orion Launch Abort Vehicle Plumes on Aerodynamics and Controllability

    NASA Technical Reports Server (NTRS)

    Vicker, Darby; Childs, Robert; Rogers,Stuart E.; McMullen, Matthew; Garcia, Joseph; Greathouse, James

    2013-01-01

    Characterization of the launch abort system of the Multi-purpose Crew Vehicle (MPCV) for control design and accurate simulation has provided a significant challenge to aerodynamicists and design engineers. The design space of the launch abort vehicle (LAV) includes operational altitudes from ground level to approximately 300,000 feet, Mach numbers from 0-9, and peak dynamic pressure near 1300psf during transonic flight. Further complicating the characterization of the aerodynamics and the resultant vehicle controllability is the interaction of the vehicle flowfield with the plumes of the two solid propellant motors that provide attitude control and the main propulsive impulse for the LAV. These interactions are a function of flight parameters such as Mach number, altitude, dynamic pressure, vehicle attitude, as well as parameters relating to the operation of the motors themselves - either as a function of time for the AM, or as a result of the flight control system requests for control torque from the ACM. This paper discusses the computational aerodynamic modeling of the aerodynamic interaction caused by main abort motor and the attitude control motor of the MPCV LAV, showing the effects of these interactions on vehicle controllability.

  16. Aerodynamic flight control to increase payload capability of future launch vehicles

    NASA Technical Reports Server (NTRS)

    Cochran, John E., Jr.; Cheng, Y.-M.; Leleux, Todd; Bigelow, Scott; Hasbrook, William

    1993-01-01

    In this report, we provide some examples of French, Russian, Chinese, and Japanese launch vehicles that have utilized fins in their designs. Next, the aerodynamic design of the fins is considered in Section 3. Some comments on basic static stability and control theory are followed by a brief description of an aerodynamic characteristics prediction code that was used to estimate the characteristics of a modified NLS 1.5 Stage vehicle. Alternative fin designs are proposed and some estimated aerodynamic characteristics presented and discussed. Also included in Section 3 is a discussion of possible methods of enhancement of the aerodynamic efficiency of fins, such as vortex generators and jet flaps. We consider the construction of fins for launch vehicles in Section 4 and offer an assessment of the state-of-the-art in the use of composites for aerodynamic control surfaces on high speed vehicles. We also comment on the use of smart materials for launch vehicle fins. The dynamic stability and control of a launch vehicle that utilizes both thrust vector control (engine nozzle gimballing) and movable fins is the subject addressed in Section 5. We give a short derivation of equations of motion for a launch vehicle moving in a vertical plane above a spherical earth, discuss the use of a gravity-turn nominal trajectory, and give the form of the period equations linearized about such a nominal. We then consider feedback control of vehicle attitude using both engine gimballing and fin deflection. Conclusions are stated and recommendations made in Section 6. An appendix contains aerodynamic data in tabular and graphical formats.

  17. X33 Reusable Launch Vehicle Control on Sliding Modes: Concepts for a Control System Development

    NASA Technical Reports Server (NTRS)

    Shtessel, Yuri B.

    1998-01-01

    Control of the X33 reusable launch vehicle is considered. The launch control problem consists of automatic tracking of the launch trajectory which is assumed to be optimally precalculated. It requires development of a reliable, robust control algorithm that can automatically adjust to some changes in mission specifications (mass of payload, target orbit) and the operating environment (atmospheric perturbations, interconnection perturbations from the other subsystems of the vehicle, thrust deficiencies, failure scenarios). One of the effective control strategies successfully applied in nonlinear systems is the Sliding Mode Control. The main advantage of the Sliding Mode Control is that the system's state response in the sliding surface remains insensitive to certain parameter variations, nonlinearities and disturbances. Employing the time scaling concept, a new two (three)-loop structure of the control system for the X33 launch vehicle was developed. Smoothed sliding mode controllers were designed to robustly enforce the given closed-loop dynamics. Simulations of the 3-DOF model of the X33 launch vehicle with the table-look-up models for Euler angle reference profiles and disturbance torque profiles showed a very accurate, robust tracking performance.

  18. Commercial motor vehicle speed control devices

    DOT National Transportation Integrated Search

    This report reviews the problem of heavy vehicle speeding (in particular, speeding at greater than 65 mph) : and speeding-related crash involvements. The report describes and assesses devices available to control : truck speed, and addresses the ques...

  19. Modern Control Aspects of Automatically Steered Vehicles

    DOT National Transportation Integrated Search

    1971-12-01

    In the study of automatically steered rubber tired vehicles, little emphasis in the past has been placed on the steering control laws. The report examines the control law problem from the state variable point of view and it is shown that, except for ...

  20. Component Control System for a Vehicle

    NASA Technical Reports Server (NTRS)

    Lee, Chunhao J. (Inventor); Fraser-Chanpong, Nathan (Inventor); Vitale, Robert L. (Inventor); Akinyode, Akinjide Akinniyi (Inventor); Dawson, Andrew D. (Inventor); Guo, Raymond (Inventor); Waligora, Thomas M. (Inventor); Spain, Ivan (Inventor); Bluethmann, William J. (Inventor); Reed, Ryan M. (Inventor)

    2016-01-01

    A vehicle includes a chassis, a modular component, and a central operating system. The modular component is supported by the chassis. The central operating system includes a component control system, a primary master controller, and a secondary master controller. The component control system is configured for controlling the modular component. The primary and secondary master controllers are in operative communication with the component control system. The primary and secondary master controllers are configured to simultaneously transmit commands to the component control system. The component control system is configured to accept commands from the secondary master controller only when a fault occurs in the primary master controller.

  1. Hybrid vehicle control

    DOEpatents

    Shallvari, Iva; Velnati, Sashidhar; DeGroot, Kenneth P.

    2015-07-28

    A method and apparatus for heating a catalytic converter's catalyst to an efficient operating temperature in a hybrid electric vehicle when the vehicle is in a charge limited mode such as e.g., the charge depleting mode or when the vehicle's high voltage battery is otherwise charge limited. The method and apparatus determine whether a high voltage battery of the vehicle is incapable of accepting a first amount of charge associated with a first procedure to warm-up the catalyst. If it is determined that the high voltage battery is incapable of accepting the first amount of charge, a second procedure with an acceptable amount of charge is performed to warm-up the catalyst.

  2. Cooperative and Integrated Vehicle and Intersection Control for Energy Efficiency (CIVIC-E²)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hou, Yunfei; Seliman, Salaheldeen M. S.; Wang, Enshu

    Recent advances in connected vehicle technologies enable vehicles and signal controllers to cooperate and improve the traffic management at intersections. This paper explores the opportunity for cooperative and integrated vehicle and intersection control for energy efficiency (CIVIC-E 2) to contribute to a more sustainable transportation system. We propose a two-level approach that jointly optimizes the traffic signal timing and vehicles' approach speed, with the objective being to minimize total energy consumption for all vehicles passing through an isolated intersection. More specifically, at the intersection level, a dynamic programming algorithm is designed to find the optimal signal timing by explicitly consideringmore » the arrival time and energy profile of each vehicle. At the vehicle level, a model predictive control strategy is adopted to ensure that vehicles pass through the intersection in a timely fashion. Our simulation study has shown that the proposed CIVIC-E 2 system can significantly improve intersection performance under various traffic conditions. Compared with conventional fixed-time and actuated signal control strategies, the proposed algorithm can reduce energy consumption and queue length by up to 31% and 95%, respectively.« less

  3. Cooperative and Integrated Vehicle and Intersection Control for Energy Efficiency (CIVIC-E²)

    DOE PAGES

    Hou, Yunfei; Seliman, Salaheldeen M. S.; Wang, Enshu; ...

    2018-02-15

    Recent advances in connected vehicle technologies enable vehicles and signal controllers to cooperate and improve the traffic management at intersections. This paper explores the opportunity for cooperative and integrated vehicle and intersection control for energy efficiency (CIVIC-E 2) to contribute to a more sustainable transportation system. We propose a two-level approach that jointly optimizes the traffic signal timing and vehicles' approach speed, with the objective being to minimize total energy consumption for all vehicles passing through an isolated intersection. More specifically, at the intersection level, a dynamic programming algorithm is designed to find the optimal signal timing by explicitly consideringmore » the arrival time and energy profile of each vehicle. At the vehicle level, a model predictive control strategy is adopted to ensure that vehicles pass through the intersection in a timely fashion. Our simulation study has shown that the proposed CIVIC-E 2 system can significantly improve intersection performance under various traffic conditions. Compared with conventional fixed-time and actuated signal control strategies, the proposed algorithm can reduce energy consumption and queue length by up to 31% and 95%, respectively.« less

  4. Role of warm saline mouth rinse in prevention of alveolar osteitis: a randomized controlled trial.

    PubMed

    Osunde, Otasowie Daniel; Bassey, Godwin Obi

    2015-01-01

    The present study was aimed at determining the role warm saline rinse in the prevention of alveolar osteitis following dental extractions. Apparently patients aged 16 and above who were referred to the Oral Surgery Clinic of our institution, with an indication for non-surgical extraction of pathologic teeth were prospectively and uniformly randomized into warm saline group and control. The experimental group (n = 80) were instructed to gargle 6 times daily with warm saline and no such instructions were given to the second group (n = 80) to serve as controls. Information on demographic, indications for extraction, and development of alveolar osteitis were obtained and analyzed. Comparative statistics were done using Pearson's chi square or Fisher's exact test as appropriate. A p value of less than 0.05 was considered significant. The demographic and other baseline parameters such as indications for extractions were comparable among the study groups (p > 0.05). The overall prevalence of alveolar osteitis was 13.7%. There was a statistical significant difference between the study groups with respect to development of alveolar osteitis (X2 = 15.00, df = 1, p = 0.001).The risk of development of alveolar osteitis was 4 times higher in the control group (OR = 4.33, P = 0.001). Warm saline mouth rinse instruction is beneficial in the prevention of development of alveolar osteitis after dental extractions.

  5. 32 CFR 228.4 - Control of vehicles on protected property.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Control of vehicles on protected property. 228.4 Section 228.4 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS SECURITY PROTECTIVE FORCE § 228.4 Control of vehicles on protected property...

  6. 40 CFR 80.24 - Controls applicable to motor vehicle manufacturers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Controls applicable to motor vehicle manufacturers. 80.24 Section 80.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... applicable to motor vehicle manufacturers. (a) [Reserved] (b) The manufacturer of any motor vehicle equipped...

  7. Communication and Control for Fleets of Autonomous Underwater Vehicles

    DTIC Science & Technology

    2006-10-30

    Washington State University (WSU) on fuzzy logic control systems [2-4] and autonomous vehicles [5-10]. The ALWSE-MC program developed at NAVSEA CSS was...rotating head sonar on crawlers as an additional sensor for navigation. We have previously investigated the use of video cameras on autonomous vehicles for...simulates autonomous vehicles performing mine reconnaissance/mapping, clearance, and surveillance in a littoral region. Three simulations were preformed

  8. Gain Scheduling for the Orion Launch Abort Vehicle Controller

    NASA Technical Reports Server (NTRS)

    McNamara, Sara J.; Restrepo, Carolina I.; Madsen, Jennifer M.; Medina, Edgar A.; Proud, Ryan W.; Whitley, Ryan J.

    2011-01-01

    One of NASAs challenges for the Orion vehicle is the control system design for the Launch Abort Vehicle (LAV), which is required to abort safely at any time during the atmospheric ascent portion of ight. The focus of this paper is the gain design and scheduling process for a controller that covers the wide range of vehicle configurations and flight conditions experienced during the full envelope of potential abort trajectories from the pad to exo-atmospheric flight. Several factors are taken into account in the automation process for tuning the gains including the abort effectors, the environmental changes and the autopilot modes. Gain scheduling is accomplished using a linear quadratic regulator (LQR) approach for the decoupled, simplified linear model throughout the operational envelope in time, altitude and Mach number. The derived gains are then implemented into the full linear model for controller requirement validation. Finally, the gains are tested and evaluated in a non-linear simulation using the vehicles ight software to ensure performance requirements are met. An overview of the LAV controller design and a description of the linear plant models are presented. Examples of the most significant challenges with the automation of the gain tuning process are then discussed. In conclusion, the paper will consider the lessons learned through out the process, especially in regards to automation, and examine the usefulness of the gain scheduling tool and process developed as applicable to non-Orion vehicles.

  9. Multi Purpose Crew Vehicle Active Thermal Control and Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Boehm, Paul; Cross, Cynthia D.; Rains, George Edward

    2014-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in September of 2014. The development of the Orion Active Thermal Control (ATCS) and Environmental Control and Life Support (ECLS) System, focused on the integrating the components into the EFT1 vehicle and preparing them for launch. Work also has started on preliminary design reviews for the manned vehicle. Additional development work is underway to keep the remaining component progressing towards implementation on the flight tests of EM1 in 2017 and of EM2 in 2020. This paper covers the Orion ECLS development from April 2013 to April 2014

  10. Electric and hybrid vehicle environmental control subsystem study

    NASA Technical Reports Server (NTRS)

    Heitner, K. L.

    1980-01-01

    An environmental control subsystem (ECS) in electric and hybrid vehicles is studied. A combination of a combustion heater and gasoline engine (Otto cycle) driven vapor compression air conditioner is selected. The combustion heater, the small gasoline engine, and the vapor compression air conditioner are commercially available. These technologies have good cost and performance characteristics. The cost for this ECS is relatively close to the cost of current ECS's. Its effect on the vehicle's propulsion battery is minimal and the ECS size and weight do not have significant impact on the vehicle's range.

  11. A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation.

    PubMed

    Zhang, Zutao; Luo, Dianyuan; Rasim, Yagubov; Li, Yanjun; Meng, Guanjun; Xu, Jian; Wang, Chunbai

    2016-02-19

    In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG) sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI) system with eight channels is designed for collecting the driver's EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT) is adopted to extract the EEG power spectrum density (PSD). In this step, sparse representation classification combined with k-singular value decomposition (KSVD) is firstly introduced in PSD to estimate the driver's vigilance level. Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model.

  12. Handling performance control for hybrid 8-wheel-drive vehicle and simulation verification

    NASA Astrophysics Data System (ADS)

    Ni, Jun; Hu, Jibin

    2016-08-01

    In order to improve handling performance of a hybrid 8-Wheel-Drive vehicle, the handling performance control strategy was proposed. For armoured vehicle, besides handling stability in high speed, the minimum steer radius in low speed is also a key tactical and technical index. Based on that, the proposed handling performance control strategy includes 'Handling Stability' and 'Radius Minimization' control modes. In 'Handling Stability' control mode, 'Neutralsteer Radio' is defined to adjust the steering characteristics to satisfy different demand in different speed range. In 'Radius Minimization' control mode, the independent motors are controlled to provide an additional yaw moment to decrease the minimum steer radius. In order to verify the strategy, a simulation platform was built including engine and continuously variable transmission systems, generator and battery systems, independent motors and controllers systems, vehicle dynamic and tyre mechanical systems. The simulation results show that the handling performance of the vehicle can be enhanced significantly, and the minimum steer radius can be decreased by 20% which is significant improvement compared to the common level of main battle armoured vehicle around the world.

  13. Advanced control design for hybrid turboelectric vehicle

    NASA Technical Reports Server (NTRS)

    Abban, Joseph; Norvell, Johnesta; Momoh, James A.

    1995-01-01

    The new environment standards are a challenge and opportunity for industry and government who manufacture and operate urban mass transient vehicles. A research investigation to provide control scheme for efficient power management of the vehicle is in progress. Different design requirements using functional analysis and trade studies of alternate power sources and controls have been performed. The design issues include portability, weight and emission/fuel efficiency of induction motor, permanent magnet and battery. A strategic design scheme to manage power requirements using advanced control systems is presented. It exploits fuzzy logic, technology and rule based decision support scheme. The benefits of our study will enhance the economic and technical feasibility of technological needs to provide low emission/fuel efficient urban mass transit bus. The design team includes undergraduate researchers in our department. Sample results using NASA HTEV simulation tool are presented.

  14. Local navigation and fuzzy control realization for autonomous guided vehicle

    NASA Astrophysics Data System (ADS)

    El-Konyaly, El-Sayed H.; Saraya, Sabry F.; Shehata, Raef S.

    1996-10-01

    This paper addresses the problem of local navigation for an autonomous guided vehicle (AGV) in a structured environment that contains static and dynamic obstacles. Information about the environment is obtained via a CCD camera. The problem is formulated as a dynamic feedback control problem in which speed and steering decisions are made on the fly while the AGV is moving. A decision element (DE) that uses local information is proposed. The DE guides the vehicle in the environment by producing appropriate navigation decisions. Dynamic models of a three-wheeled vehicle for driving and steering mechanisms are derived. The interaction between them is performed via the local feedback DE. A controller, based on fuzzy logic, is designed to drive the vehicle safely in an intelligent and human-like manner. The effectiveness of the navigation and control strategies in driving the AGV is illustrated and evaluated.

  15. Salinization and Saline Environments

    NASA Astrophysics Data System (ADS)

    Vengosh, A.

    2003-12-01

    One of the most conspicuous phenomena of water-quality degradation, particularly in arid and semi-arid zones, is salinization of water and soil resources. Salinization is a long-term phenomenon, and during the last century many aquifers and river basins have become unsuitable for human consumption owing to high levels of salinity. Future exploitation of thousands of wells in the Middle East and in many other water-scarce regions in the world depends, to a large extent, on the degree and rate of salinization. Moreover, every year a large fraction of agricultural land is salinized and becomes unusable.Salinization is a global environmental phenomenon that affects many different aspects of our life (Williams, 2001a, b): changing the chemical composition of natural water resources (lakes, rivers, and groundwater), degrading the quality of water supply to the domestic and agriculture sectors, contribution to loss of biodiversity, taxonomic replacement by halotolerant species ( Williams, 2001a, b), loss of fertile soil, collapse of agricultural and fishery industries, changing of local climatic conditions, and creating severe health problems (e.g., the Aral Basin). The damage due to salinity in the Colorado River Basin alone, for example, ranges between 500 and 750 million per year and could exceed 1 billion per year if the salinity in the Imperial Dam increases from 700 mg L-1 to 900 mg L-1 (Bureau of Reclamation, 2003, USA). In Australia, accelerating soil salinization has become a massive environmental and economic disaster. Western Australia is "losing an area equal to one football oval an hour" due to spreading salinity ( Murphy, 1999). The annual cost for dryland salinity in Australia is estimated as AU700 million for lost land and AU$130 million for lost production ( Williams et al., 2002). In short, the salinization process has become pervasive.Salinity in water is usually defined by the chloride content (mg L-1) or total dissolved solids content (TDS, mg L-1or g

  16. Vehicle health management for guidance, navigation and control systems

    NASA Technical Reports Server (NTRS)

    Radke, Kathleen; Frazzini, Ron; Bursch, Paul; Wald, Jerry; Brown, Don

    1993-01-01

    The objective of the program was to architect a vehicle health management (VHM) system for space systems avionics that assures system readiness for launch vehicles and for space-based dormant vehicles. The platforms which were studied and considered for application of VHM for guidance, navigation and control (GN&C) included the Advanced Manned Launch System (AMLS), the Horizontal Landing-20/Personnel Launch System (HL-20/PLS), the Assured Crew Return Vehicle (ACRV) and the Extended Duration Orbiter (EDO). This set was selected because dormancy and/or availability requirements are driving the designs of these future systems.

  17. Slip control design of electric vehicle using indirect Dahlin Adaptive Pid

    NASA Astrophysics Data System (ADS)

    Fauzi, I. R.; Koko, F.; Kirom, M. R.

    2016-11-01

    In this paper the problem to be solved is to build a slip control on a wheel that may occur in an electric car wheel. Slip is the difference in vehicle velocity and wheel tangential velocity and to be enlarged when the torque given growing. Slip can be reduced by controlling the torque of the wheel so that the wheel tangential speed does not exceed the vehicle speed. The experiment in this paper is a simulation using MATLAB Simulink and using Adaptive control. The response adaptive PID control more quickly 1.5 s than PID control and can controlled wheel tangential speed close to the vehicle velocity on a dry asphalt, wet asphalt, snow and ice surface sequent at time 2s, 4s, 10s, and 50s. The maximum acceleration of the vehicle (V) on the surface of the dry asphalt, wet asphalt, snow, and ice surface sequent at 8.9 m/s2, 6.2 m/s2, 2.75 m/s2, and 0.34 m/s2.

  18. Salinity controls on Na incorporation in Red Sea planktonic foraminifera

    NASA Astrophysics Data System (ADS)

    Mezger, E. M.; de Nooijer, L. J.; Boer, W.; Brummer, G. J. A.; Reichart, G. J.

    2016-12-01

    Whereas several well-established proxies are available for reconstructing past temperatures, salinity remains challenging to assess. Reconstructions based on the combination of (in)organic temperature proxies and foraminiferal stable oxygen isotopes result in relatively large uncertainties, which may be reduced by application of a direct salinity proxy. Cultured benthic and planktonic foraminifera showed that Na incorporation in foraminiferal shell calcite provides a potential independent proxy for salinity. Here we present the first field calibration of such a potential proxy. Living planktonic foraminiferal specimens from the Red Sea surface waters were collected and analyzed for their Na/Ca content using laser ablation quadrupole inductively coupled plasma mass spectrometry. Using the Red Sea as a natural laboratory, the calibration covers a broad range of salinities over a steep gradient within the same water mass. For both Globigerinoides ruber and Globigerinoides sacculifer calcite Na/Ca increases with salinity, albeit with a relatively large intraspecimen and interspecimen variability. The field-based calibration is similar for both species from a salinity of 36.8 up to 39.6, while values for G. sacculifer deviate from this trend in the northernmost transect. It is hypothesized that the foraminifera in the northernmost part of the Red Sea are (partly) expatriated and hence should be excluded from the Na/Ca-salinity calibration. Incorporation of Na in foraminiferal calcite therefore provides a potential proxy for salinity, although species-specific calibrations are still required and more research on the effect of temperature is needed.

  19. A Vehicle Active Safety Model: Vehicle Speed Control Based on Driver Vigilance Detection Using Wearable EEG and Sparse Representation

    PubMed Central

    Zhang, Zutao; Luo, Dianyuan; Rasim, Yagubov; Li, Yanjun; Meng, Guanjun; Xu, Jian; Wang, Chunbai

    2016-01-01

    In this paper, we present a vehicle active safety model for vehicle speed control based on driver vigilance detection using low-cost, comfortable, wearable electroencephalographic (EEG) sensors and sparse representation. The proposed system consists of three main steps, namely wireless wearable EEG collection, driver vigilance detection, and vehicle speed control strategy. First of all, a homemade low-cost comfortable wearable brain-computer interface (BCI) system with eight channels is designed for collecting the driver’s EEG signal. Second, wavelet de-noising and down-sample algorithms are utilized to enhance the quality of EEG data, and Fast Fourier Transformation (FFT) is adopted to extract the EEG power spectrum density (PSD). In this step, sparse representation classification combined with k-singular value decomposition (KSVD) is firstly introduced in PSD to estimate the driver’s vigilance level . Finally, a novel safety strategy of vehicle speed control, which controls the electronic throttle opening and automatic braking after driver fatigue detection using the above method, is presented to avoid serious collisions and traffic accidents. The simulation and practical testing results demonstrate the feasibility of the vehicle active safety model. PMID:26907278

  20. Real World Crash Evaluation of Vehicle Stability Control (VSC) Technology

    PubMed Central

    Bahouth, G.

    2005-01-01

    This study quantifies the effect of Vehicle Stability Control (VSC) in reducing crash involvement rates for a subset of vehicles in the US fleet. Crash rates for a variety of impact types before and after VSC technology was implemented are compared. Police-reported crashes from six available US state files from 1998–2002 were analyzed including 13,987 crash-involved study vehicles not equipped with the technology and 5,671 crashes of vehicles equipped with VSC as a standard feature. Overall, an 11.2% (95% CI: 2.4%, 21.1%) reduction in multi-vehicle frontal crash involvement was identified for VSC-equipped vehicles. A 52.6% (95% CI: 42.5%, 62.7%) reduction in single-vehicle crash rates was found. PMID:16179137

  1. Real world crash evaluation of vehicle stability control (VSC) technology.

    PubMed

    Bahouth, G

    2005-01-01

    This study quantifies the effect of Vehicle Stability Control (VSC) in reducing crash involvement rates for a subset of vehicles in the US fleet. Crash rates for a variety of impact types before and after VSC technology was implemented are compared. Police-reported crashes from six available US state files from 1998-2002 were analyzed including 13,987 crash-involved study vehicles not equipped with the technology and 5,671 crashes of vehicles equipped with VSC as a standard feature. Overall, an 11.2% (95% CI: 2.4%, 21.1%) reduction in multi-vehicle frontal crash involvement was identified for VSC-equipped vehicles. A 52.6% (95% CI: 42.5%, 62.7%) reduction in single-vehicle crash rates was found.

  2. Proprioceptive Sensors' Fault Tolerant Control Strategy for an Autonomous Vehicle.

    PubMed

    Boukhari, Mohamed Riad; Chaibet, Ahmed; Boukhnifer, Moussa; Glaser, Sébastien

    2018-06-09

    In this contribution, a fault-tolerant control strategy for the longitudinal dynamics of an autonomous vehicle is presented. The aim is to be able to detect potential failures of the vehicle's speed sensor and then to keep the vehicle in a safe state. For this purpose, the separation principle, composed of a static output feedback controller and fault estimation observers, is designed. Indeed, two observer techniques were proposed: the proportional and integral observer and the descriptor observer. The effectiveness of the proposed scheme is validated by means of the experimental demonstrator of the VEDECOM (Véhicle Décarboné et Communinicant) Institut.

  3. Multi Purpose Crew Vehicle Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Cross, Cynthia D.; Carrasquillo, Robyn; Rains, George Edward

    2011-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely from the Earth beyond Earth orbit. This year, the vehicle focused on building the Orion Flight Test 1 (OFT1) vehicle to be launched in 2013. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the components which are on OFT1 which includes pressure control and active thermal control systems, is progressing through the design stage into manufacturing. Additional development work was done to keep the remaining component progressing towards implementation for a flight test in 2017. This paper covers the Orion ECLS development from April 2011 to April 2012.

  4. Response of lead-acid batteries to chopper-controlled discharge. [for electric vehicles

    NASA Technical Reports Server (NTRS)

    Cataldo, R. L.

    1978-01-01

    The results of tests on an electric vehicle battery, using a simulated electric vehicle chopper-speed controller, show energy output losses up to 25 percent compared to constant current discharges at the same average current of 100 A. However, an energy output increase of 22 percent is noticed at the 200 A average level and 44 percent increase at the 300 A level using pulse discharging. Because of these complex results, electric vehicle battery/speed controller interactions must be considered in vehicle design.

  5. Consensus seeking, formation keeping, and trajectory tracking in multiple vehicle cooperative control

    NASA Astrophysics Data System (ADS)

    Ren, Wei

    Cooperative control problems for multiple vehicle systems can be categorized as either formation control problems with applications to mobile robots, unmanned air vehicles, autonomous underwater vehicles, satellites, aircraft, spacecraft, and automated highway systems, or non-formation control problems such as task assignment, cooperative transport, cooperative role assignment, air traffic control, cooperative timing, and cooperative search. The cooperative control of multiple vehicle systems poses significant theoretical and practical challenges. For cooperative control strategies to be successful, numerous issues must be addressed. We consider three important and correlated issues: consensus seeking, formation keeping, and trajectory tracking. For consensus seeking, we investigate algorithms and protocols so that a team of vehicles can reach consensus on the values of the coordination data in the presence of imperfect sensors, communication dropout, sparse communication topologies, and noisy and unreliable communication links. The main contribution of this dissertation in this area is that we show necessary and/or sufficient conditions for consensus seeking with limited, unidirectional, and unreliable information exchange under fixed and switching interaction topologies (through either communication or sensing). For formation keeping, we apply a so-called "virtual structure" approach to spacecraft formation flying and multi-vehicle formation maneuvers. As a result, single vehicle path planning and trajectory generation techniques can be employed for the virtual structure while trajectory tracking strategies can be employed for each vehicle. The main contribution of this dissertation in this area is that we propose a decentralized architecture for multiple spacecraft formation flying in deep space with formation feedback introduced. This architecture ensures the necessary precision in the presence of actuator saturation, internal and external disturbances, and

  6. Could high salinity be used to control bullfrogs in small ponds?

    USGS Publications Warehouse

    Ward, David L.; Finch, Colton; Blasius, Heidi

    2015-01-01

    We examined survival of bullfrog (Rana catesbeiana) eggs and tadpoles at 3 ppt and 6 ppt salinity in the laboratory to determine if low-level salinity could be used to eradicate bullfrogs from small ponds that contain native fishes. Bullfrog eggs and tadpoles <10 days old experienced 100% mortality when held at 6 ppt salinity for 10 days. Bullfrog tadpoles 10–15 days old experienced significantly reduced survival when exposed to salinity of 6 ppt for 10 days. Older bullfrog tadpoles (>9 months old) appeared unaffected by 14 days of 6 ppt salinity. Salinity of 3 ppt did not impact survival of bullfrog tadpole eggs or tadpoles at any of the life stages we tested. Adding salt to ponds in the early spring to increase salinity to 6 ppt may be a cost effective way to eradicate bullfrogs from small ponds without harming native fishes.

  7. Dynamic modeling and ascent flight control of Ares-I Crew Launch Vehicle

    NASA Astrophysics Data System (ADS)

    Du, Wei

    This research focuses on dynamic modeling and ascent flight control of large flexible launch vehicles such as the Ares-I Crew Launch Vehicle (CLV). A complete set of six-degrees-of-freedom dynamic models of the Ares-I, incorporating its propulsion, aerodynamics, guidance and control, and structural flexibility, is developed. NASA's Ares-I reference model and the SAVANT Simulink-based program are utilized to develop a Matlab-based simulation and linearization tool for an independent validation of the performance and stability of the ascent flight control system of large flexible launch vehicles. A linearized state-space model as well as a non-minimum-phase transfer function model (which is typical for flexible vehicles with non-collocated actuators and sensors) are validated for ascent flight control design and analysis. This research also investigates fundamental principles of flight control analysis and design for launch vehicles, in particular the classical "drift-minimum" and "load-minimum" control principles. It is shown that an additional feedback of angle-of-attack can significantly improve overall performance and stability, especially in the presence of unexpected large wind disturbances. For a typical "non-collocated actuator and sensor" control problem for large flexible launch vehicles, non-minimum-phase filtering of "unstably interacting" bending modes is also shown to be effective. The uncertainty model of a flexible launch vehicle is derived. The robust stability of an ascent flight control system design, which directly controls the inertial attitude-error quaternion and also employs the non-minimum-phase filters, is verified by the framework of structured singular value (mu) analysis. Furthermore, nonlinear coupled dynamic simulation results are presented for a reference model of the Ares-I CLV as another validation of the feasibility of the ascent flight control system design. Another important issue for a single main engine launch vehicle is

  8. Full drive-by-wire dynamic control for four-wheel-steer all-wheel-drive vehicles

    NASA Astrophysics Data System (ADS)

    Fahimi, Farbod

    2013-03-01

    Most of the controllers introduced for four-wheel-steer (4WS) vehicles are derived with the assumption that the longitudinal speed of the vehicle is constant. However, in real applications, the longitudinal speed varies, and the longitudinal, lateral, and yaw dynamics are coupled. In this paper, the longitudinal dynamics of the vehicle as well as its lateral and yaw motions are controlled simultaneously. This way, the effect of driving/braking forces of the tires on the lateral and yaw motions of the vehicle are automatically included in the control laws. To address the dynamic parameter uncertainty of the vehicle, a chatter-free variable structure controller is introduced. Elimination of chatter is achieved by introducing a dynamically adaptive boundary layer thickness. It is shown via simulations that the proposed control approach performs more robustly than the controllers developed based on dynamic models, in which longitudinal speed is assumed to be constant, and only lateral speed and yaw rate are used as system states. Furthermore, this approach supports all-wheel-drive vehicles. Front-wheel-drive or rear-wheel-drive vehicles are also supported as special cases of an all-wheel-drive vehicle.

  9. Orion Multi-Purpose Crew Vehicle Active Thermal Control and Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Boehm, Paul; Cross, Cynthia D.; Rains, George Edward

    2014-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in September of 2014. The development of the Orion Active Thermal Control (ATCS) and Environmental Control and Life Support (ECLS) System, focused on the integrating the components into the EFT1 vehicle and preparing them for launch. Work also has started on preliminary design reviews for the manned vehicle. Additional development work is underway to keep the remaining component progressing towards implementation on the flight tests of EM1 in 2017 and of EM2 in 2020. This paper covers the Orion ECLS development from April 2013 to April 2014.

  10. Control of maglev vehicles with aerodynamic and guideway disturbances

    NASA Technical Reports Server (NTRS)

    Flueckiger, Karl; Mark, Steve; Caswell, Ruth; Mccallum, Duncan

    1994-01-01

    A modeling, analysis, and control design methodology is presented for maglev vehicle ride quality performance improvement as measured by the Pepler Index. Ride quality enhancement is considered through active control of secondary suspension elements and active aerodynamic surfaces mounted on the train. To analyze and quantify the benefits of active control, the authors have developed a five degree-of-freedom lumped parameter model suitable for describing a large class of maglev vehicles, including both channel and box-beam guideway configurations. Elements of this modeling capability have been recently employed in studies sponsored by the U.S. Department of Transportation (DOT). A perturbation analysis about an operating point, defined by vehicle and average crosswind velocities, yields a suitable linearized state space model for multivariable control system analysis and synthesis. Neglecting passenger compartment noise, the ride quality as quantified by the Pepler Index is readily computed from the system states. A statistical analysis is performed by modeling the crosswind disturbances and guideway variations as filtered white noise, whereby the Pepler Index is established in closed form through the solution to a matrix Lyapunov equation. Data is presented which indicates the anticipated ride quality achieved through various closed-loop control arrangements.

  11. Salinity Management in Agriculture

    USDA-ARS?s Scientific Manuscript database

    Existing guidelines and standards for reclamation of saline soils and management to control salinity exist but have not been updated for over 25 years. In the past few years a looming water scarcity has resulted in questioning of the long term future of irrigation projects in arid and semi arid regi...

  12. Hypersonic vehicle control law development using H infinity and mu-synthesis

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.; Chowdhry, Rajiv S.; Mcminn, John D.; Shaughnessy, John D.

    1992-01-01

    Applicability and effectiveness of robust control techniques to a single-stage-to-orbit (SSTO) airbreathing hypersonic vehicle on an ascent accelerating path and their effectiveness are explored in this paper. An SSTO control system design problem, requiring high accuracy tracking of velocity and altitude commands while limiting angle of attack oscillations, minimizing control power usage and stabilizing the vehicle all in the presence of atmospheric turbulence and uncertainty in the system, was formulated to compare results of the control designs using H infinity and mu-synthesis procedures. The math model, an integrated flight/propulsion dynamic model of a conical accelerator class vehicle, was linearized as the vehicle accelerated through Mach 8. Controller analysis was conducted using the singular value technique and the mu-analysis approach. Analysis results were obtained in both the frequency and the time domains. The results clearly demonstrate the inherent advantages of the structured singular value framework for this class of problems. Since payload performance margins are so critical for the SSTO mission, it is crucial that adequate stability margins be provided without sacrificing any payload mass.

  13. Human Engineering of Space Vehicle Displays and Controls

    NASA Technical Reports Server (NTRS)

    Whitmore, Mihriban; Holden, Kritina L.; Boyer, Jennifer; Stephens, John-Paul; Ezer, Neta; Sandor, Aniko

    2010-01-01

    Proper attention to the integration of the human needs in the vehicle displays and controls design process creates a safe and productive environment for crew. Although this integration is critical for all phases of flight, for crew interfaces that are used during dynamic phases (e.g., ascent and entry), the integration is particularly important because of demanding environmental conditions. This panel addresses the process of how human engineering involvement ensures that human-system integration occurs early in the design and development process and continues throughout the lifecycle of a vehicle. This process includes the development of requirements and quantitative metrics to measure design success, research on fundamental design questions, human-in-the-loop evaluations, and iterative design. Processes and results from research on displays and controls; the creation and validation of usability, workload, and consistency metrics; and the design and evaluation of crew interfaces for NASA's Crew Exploration Vehicle are used as case studies.

  14. Design of driving control strategy of torque distribution for two - wheel independent drive electric vehicle

    NASA Astrophysics Data System (ADS)

    Zhang, Chuanwei; Zhang, Dongsheng; Wen, Jianping

    2018-02-01

    In order to coordinately control the torque distribution of existing two-wheel independent drive electric vehicle, and improve the energy efficiency and control stability of the whole vehicle, the control strategies based on fuzzy control were designed which adopt the direct yaw moment control as the main line. For realizing the torque coordination simulation of the two-wheel independent drive vehicle, the vehicle model, motor model and tire model were built, including the vehicle 7 - DOF dynamics model, motion equation, torque equation. Finally, in the Carsim - Simulink joint simulation platform, the feasibility of the drive control strategy was verified.

  15. B-52 control configured vehicles: Flight test results

    NASA Technical Reports Server (NTRS)

    Arnold, J. I.; Murphy, F. B.

    1976-01-01

    Recently completed B-52 Control Configured Vehicles (CCV) flight testing is summarized, and results are compared to analytical predictions. Results are presented for five CCV system concepts: ride control, maneuver load control, flutter mode control, augmented stability, and fatigue reduction. Test results confirm analytical predictions and show that CCV system concepts achieve performance goals when operated individually or collectively.

  16. Nasal saline for chronic sinonasal symptoms: a randomized controlled trial.

    PubMed

    Pynnonen, Melissa A; Mukerji, Shraddha S; Kim, H Myra; Adams, Meredith E; Terrell, Jeffrey E

    2007-11-01

    To determine if isotonic sodium chloride (hereinafter "saline") nasal irrigations performed with large volume and delivered with low positive pressure are more effective than saline sprays at improving quality of life and decreasing medication use. A prospective, randomized controlled trial. Community. A total of 127 adults with chronic nasal and sinus symptoms. Patients were randomly assigned to irrigation performed with large volume and delivered with low positive pressure (n = 64) or spray (n = 63) for 8 weeks. Change in symptom severity measured by mean 20-Item Sino-Nasal Outcome Test (SNOT-20) score; change in symptom frequency measured with a global question; and change in medication use. A total of 121 patients were evaluable. The irrigation group achieved lower SNOT-20 scores than the spray group at all 3 time points: 4.4 points lower at 2 weeks (P = .02); 8.2 points lower at 4 weeks (P < .001); and 6.4 points lower at 8 weeks (P = .002). When symptom frequency was analyzed, 40% of subjects in the irrigation group reported symptoms "often or always" at 8 weeks compared with 61% in the spray group (absolute risk reduction, 0.2; 95% confidence interval, 0.02-0.38 (P = .01). No significant differences in sinus medication use were seen between groups. Nasal irrigations performed with large volume and delivered with low positive pressure are more effective than saline sprays for treatment of chronic nasal and sinus symptoms in a community-based population.

  17. Vehicle-dependent disposition kinetics of fluoranthene in Fisher-344 rats.

    PubMed

    Harris, Deacqunita L; Hood, Darry B; Ramesh, Aramandla

    2008-03-01

    The objective of this study was to evaluate how the vehicles of choice affect the pharmacokinetics of orally administered Fluoranthene [FLA] in rats. Fluoranthene is a member of the family of Polycyclic Aromatic Hydrocarbon chemicals. Fluoranthene exposure to humans may occur as a result of cigarette smoking, consumption of contaminated food and water, heating woods in stoves and boilers, industrial sources such as coal gasification, carbon and graphite electrode manufacturing. Adult male Fisher-344 rats were given single oral doses of 25 and 50 microg/kg FLA in tricaprylin, peanut oil, cod liver oil, Tween 80/isotonic saline (1:5) and 2% Alkamuls-EL620 through gavage. After administration, the rats were housed individually in metabolic cages and sacrificed at 2, 4, 6, 8, 10 and 12 hours post FLA exposure. Blood, lung, liver, small intestine, adipose tissue samples, urine, and feces were collected at each time point. Samples were subjected to a liquid-liquid extraction using methanol, chloroform, and water. The extracts were analyzed by a reverse-phase HPLC, equipped with a fluorescence detector. The results revealed a dose-dependent increase in FLA concentrations in plasma and tissues for all the vehicles used. Plasma and tissue FLA concentrations were greater for peanut oil; cod liver oil, and tricaprylin vehicles compared to Alkamuls (p < 0.05), and Tween 80/isotonic saline (1:5). Most of the FLA administered through peanut oil, cod liver oil and tricaprylin was cleared from the body by 8 hours (90%) and 12 hours (80%) post administration for the 25 microg/kg and 50 microg/kg dose groups, respectively. With both doses employed, the metabolism of FLA was highest when cod liver oil was used as a vehicle and lowest in vehicles containing detergent/water [cod liver oil > peanut oil > tricaprylin > alkamuls > Tween 80/isotonic saline (1:5)]. These findings suggest that uptake and elimination of FLA is accelerated when administered through oil-based vehicles. The low

  18. Study on Active Suppression Control of Drivetrain Oscillations in an Electric Vehicle

    NASA Astrophysics Data System (ADS)

    Huang, Lei; Cui, Ying

    2017-07-01

    Due to the low damping in a central driven electric vehicle and lack of passive damping mechanisms as compared with a conventional vehicle, the vehicle may endure torsional vibrations which may deteriorates the vehicle’s drivability. Thus active damping control strategy is required to reduce the undesirable oscillations in an EV. In this paper, the origin of the vibration and the design of a damping control method to suppress such oscillations to improve the drivability of an EV are studied. The traction motor torque that is given by the vehicle controller is adjusted according to the acceleration rate of the motor speed to attenuate the resonant frequency. Simulations and experiments are performed to validate the system. The results show that the proposed control system can effectively suppress oscillations and hence improve drivability.

  19. A novel integrated chassis controller for full drive-by-wire vehicles

    NASA Astrophysics Data System (ADS)

    Song, Pan; Tomizuka, Masayoshi; Zong, Changfu

    2015-02-01

    In this paper, a systematic design with multiple hierarchical layers is adopted in the integrated chassis controller for full drive-by-wire vehicles. A reference model and the optimal preview acceleration driver model are utilised in the driver control layer to describe and realise the driver's anticipation of the vehicle's handling characteristics, respectively. Both the sliding mode control and terminal sliding mode control techniques are employed in the vehicle motion control (MC) layer to determine the MC efforts such that better tracking performance can be attained. In the tyre force allocation layer, a polygonal simplification method is proposed to deal with the constraints of the tyre adhesive limits efficiently and effectively, whereby the load transfer due to both roll and pitch is also taken into account which directly affects the constraints. By calculating the motor torque and steering angle of each wheel in the executive layer, the total workload of four wheels is minimised during normal driving, whereas the MC efforts are maximised in extreme handling conditions. The proposed controller is validated through simulation to improve vehicle stability and handling performance in both open- and closed-loop manoeuvres.

  20. Investigations of Control Surface Seals for Re-entry Vehicles

    NASA Technical Reports Server (NTRS)

    Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; Curry, Donald M.; DeMange, Jeffrey J.; Rivers, H. Kevin; Hsu, Su-Yuen

    2002-01-01

    Re-entry vehicles generally require control surfaces (e.g., rudders, body flaps) to steer them during flight. Control surface seals are installed along hinge lines and where control surface edges move close to the vehicle body. These seals must operate at high temperatures and limit heat transfer to underlying structures to prevent them from overheating and causing possible loss of vehicle structural integrity. This paper presents results for thermal analyses and mechanical testing conducted on the baseline rudder/fin seal design for the X-38 re-entry vehicle. Exposure of the seals in a compressed state at the predicted peak seal temperature of 1900 F resulted in loss of seal resiliency. The vertical Inconel rudder/fin rub surface was re-designed to account for this loss of resiliency. Room temperature compression tests revealed that seal unit loads and contact pressures were below limits set to protect Shuttle thermal tiles on the horizontal sealing surface. The seals survived an ambient temperature 1000 cycle scrub test over sanded Shuttle tiles and were able to disengage and re-engage the tile edges during testing. Arc jet tests confirmed the need for seals in the rudder/fin gap location because a single seal caused a large temperature drop (delta T = 1710 F) in the gap.

  1. Effectiveness of electronic stability control on single-vehicle accidents.

    PubMed

    Lyckegaard, Allan; Hels, Tove; Bernhoft, Inger Marie

    2015-01-01

    This study aims at evaluating the effectiveness of electronic stability control (ESC) on single-vehicle injury accidents while controlling for a number of confounders influencing the accident risk. Using police-registered injury accidents from 2004 to 2011 in Denmark with cars manufactured in the period 1998 to 2011 and the principle of induced exposure, 2 measures of the effectiveness of ESC were calculated: The crude odds ratio and the adjusted odds ratio, the latter by means of logistic regression. The logistic regression controlled for a number of confounding factors, of which the following were significant. For the driver: Age, gender, driving experience, valid driving license, and seat belt use. For the vehicle: Year of registration, weight, and ESC. For the accident surroundings: Visibility, light, and location. Finally, for the road: Speed limit, surface, and section characteristics. The present study calculated the crude odds ratio for ESC-equipped cars of getting in a single-vehicle injury accident as 0.40 (95% confidence interval [CI], 0.34-0.47) and the adjusted odds ratio as 0.69 (95% CI, 0.54-0.88). No difference was found in the effectiveness of ESC across the injury severity categories (slight, severe, and fatal). In line with previous results, this study concludes that ESC reduces the risk for single-vehicle injury accidents by 31% when controlling for various confounding factors related to the driver, the car, and the accident surroundings. Furthermore, it is concluded that it is important to control for human factors (at a minimum age and gender) in analyses where evaluations of this type are performed.

  2. Simulation Research on Vehicle Active Suspension Controller Based on G1 Method

    NASA Astrophysics Data System (ADS)

    Li, Gen; Li, Hang; Zhang, Shuaiyang; Luo, Qiuhui

    2017-09-01

    Based on the order relation analysis method (G1 method), the optimal linear controller of vehicle active suspension is designed. The system of the main and passive suspension of the single wheel vehicle is modeled and the system input signal model is determined. Secondly, the system motion state space equation is established by the kinetic knowledge and the optimal linear controller design is completed with the optimal control theory. The weighting coefficient of the performance index coefficients of the main passive suspension is determined by the relational analysis method. Finally, the model is simulated in Simulink. The simulation results show that: the optimal weight value is determined by using the sequence relation analysis method under the condition of given road conditions, and the vehicle acceleration, suspension stroke and tire motion displacement are optimized to improve the comprehensive performance of the vehicle, and the active control is controlled within the requirements.

  3. A Saturation Balancing Control Method for Enhancing Dynamic Vehicle Stability (PREPRINT)

    DTIC Science & Technology

    2011-03-01

    force estimation; axle saturation level; independent drive; torque biasing; 1. Introduction Vehicle stability control ( VSC ) systems have widely been...shown to reduce accidents by minimizing driver’s loss of control during aggressive emergency maneuvers. VSC systems manipulate one or more of the... VSC (also referred to as vehicle dynamics control (VDC)) systems available on the market today are brake-based systems which extend the functionality

  4. 78 FR 29815 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ...This action would establish more stringent vehicle emissions standards and reduce the sulfur content of gasoline beginning in 2017, as part of a systems approach to addressing the impacts of motor vehicles and fuels on air quality and public health. The proposed gasoline sulfur standard would make emission control systems more effective for both existing and new vehicles, and would enable more stringent vehicle emissions standards. The proposed vehicle standards would reduce both tailpipe and evaporative emissions from passenger cars, light-duty trucks, medium-duty passenger vehicles, and some heavy-duty vehicles. This would result in significant reductions in pollutants such as ozone, particulate matter, and air toxics across the country and help state and local agencies in their efforts to attain and maintain health-based National Ambient Air Quality Standards. Motor vehicles are an important source of exposure to air pollution both regionally and near roads. These proposed vehicle standards are intended to harmonize with California's Low Emission Vehicle program, thus creating a federal vehicle emissions program that would allow automakers to sell the same vehicles in all 50 states. The proposed vehicle standards would be implemented over the same timeframe as the greenhouse gas/fuel efficiency standards for light-duty vehicles, as part of a comprehensive approach toward regulating emissions from motor vehicles.

  5. Vehicle Hybrid Braking Control Using Sliding Mode Control

    NASA Astrophysics Data System (ADS)

    Kasahara, Misawa; Kanai, Yuki; Shiraki, Ryoko; Mori, Yasuchika

    Anti-lock brake system and brake-by-wire are proposed in the vehicle control using a brake, and the braking power is expected to be improved more than ever. The researches such as an application to the ABS of Siliding mode control which considered a actuator dynamics and a hybrid control of the brake using model reference adaptive control are done so far. However, in the former case, speed following that becomes a target exists physically impossible situation by saturation of tire frictional force because only speed following is done. In the latter, the model error is caused because the simulation model and the controller design model are different. Therefore, there is a problem that an accurate follow cannot be done. In this paper, the braking control is performed using the sliding mode control which has high robustness for disturbance that fulfils matching conditions. In so doing, it aims at the achievement of optimal braking control to switch wheel speed following to slip ratio following.

  6. Control method for high-pressure hydrogen vehicle fueling station dispensers

    DOEpatents

    Kountz, Kenneth John; Kriha, Kenneth Robert; Liss, William E.

    2006-06-13

    A method for quick filling a vehicle hydrogen storage vessel with hydrogen, the key component of which is an algorithm used to control the fill process, which interacts with the hydrogen dispensing apparatus to determine the vehicle hydrogen storage vessel capacity.

  7. The Role of Guidance, Navigation, and Control in Hypersonic Vehicle Multidisciplinary Design and Optimization

    NASA Technical Reports Server (NTRS)

    Ouzts, Peter J.; Soloway, Donald I.; Moerder, Daniel D.; Wolpert, David H.; Benavides, Jose Victor

    2009-01-01

    Airbreathing hypersonic systems offer distinct performance advantages over rocket-based systems for space access vehicles. However, these performance advantages are dependent upon advances in current state-of-the-art technologies in many areas such as ram/scramjet propulsion integration, high temperature materials, aero-elastic structures, thermal protection systems, transition to hypersonics and hypersonic control elements within the framework of complex physics and new design methods. The complex interactions between elements of an airbreathing hypersonic vehicle represent a new paradigm in vehicle design to achieve the optimal performance necessary to meet space access mission objectives. In the past, guidance, navigation, and control (GNC) analysis often follows completion of the vehicle conceptual design process. Individual component groups design subsystems which are then integrated into a vehicle configuration. GNC is presented the task of developing control approaches to meet vehicle performance objectives given that configuration. This approach may be sufficient for vehicles where significant performance margins exist. However, for higher performance vehicles engaging the GNC discipline too late in the design cycle has been costly. For example, the X-29 experimental flight vehicle was built as a technology demonstrator. One of the many technologies to be demonstrated was the use of light-weight material composites for structural components. The use of light-weight materials increased the flexibility of the X- 29 beyond that of conventional metal alloy constructed aircraft. This effect was not considered when the vehicle control system was designed and built. The impact of this is that the control system did not have enough control authority to compensate for the effects of the first fundamental structural mode of the vehicle. As a result, the resulting pitch rate response of the vehicle was below specification and no post-design changes could recover the

  8. Model Identification and Control System Design for the Lambda Unmanned Research Vehicle

    DTIC Science & Technology

    1991-09-01

    AD-A241 859 D T IC_ _ _ _ _ __ OCT 21921MODEL IDENTIFICATION AND CONTROL SYSTEM DESIGN FOR THE LAMBDA UNMANNED RESEARCH VEHICLE: THESIS Gerald A...23 191K MODEL IDENTIFICATION AND CONTROL SYSTEM DESIGN FOR THE LAMBDA UNMANNED RESEARCH VEHICLE THESIS Gerald A. Swift, First Lieutenant, USAF AFIT...UNMANNED RESEARCH VEHICLE THESIS Presented to the Faculty of the School of Engineering of the Air Force Institute of Technology Air University in Partial

  9. Vehicle Steering control: A model of learning

    NASA Technical Reports Server (NTRS)

    Smiley, A.; Reid, L.; Fraser, M.

    1978-01-01

    A hierarchy of strategies were postulated to describe the process of learning steering control. Vehicle motion and steering control data were recorded for twelve novices who drove an instrumented car twice a week during and after a driver training course. Car-driver describing functions were calculated, the probable control structure determined, and the driver-alone transfer function modelled. The data suggested that the largest changes in steering control with learning were in the way the driver used the lateral position cue.

  10. System controls challenges of hypersonic combined-cycle engine powered vehicles

    NASA Technical Reports Server (NTRS)

    Morrison, Russell H.; Ianculescu, George D.

    1992-01-01

    Hypersonic aircraft with air-breathing engines have been described as the most complex and challenging air/space vehicle designs ever attempted. This is particularly true for aircraft designed to accelerate to orbital velocities. The propulsion system for the National Aerospace Plane will be an active factor in maintaining the aircraft on course. Typically addressed are the difficulties with the aerodynamic vehicle design and development, materials limitations and propulsion performance. The propulsion control system requires equal materials limitations and propulsion performance. The propulsion control system requires equal concern. Far more important than merely a subset of propulsion performance, the propulsion control system resides at the crossroads of trajectory optimization, engine static performance, and vehicle-engine configuration optimization. To date, solutions at these crossroads are multidisciplinary and generally lag behind the broader performance issues. Just how daunting these demands will be is suggested. A somewhat simplified treatment of the behavioral characteristics of hypersonic aircraft and the issues associated with their air-breathing propulsion control system design are presented.

  11. Launch vehicle flight control augmentation using smart materials and advanced composites (CDDF Project 93-05)

    NASA Technical Reports Server (NTRS)

    Barret, C.

    1995-01-01

    The Marshall Space Flight Center has a rich heritage of launch vehicles that have used aerodynamic surfaces for flight stability such as the Saturn vehicles and flight control such as on the Redstone. Recently, due to aft center-of-gravity locations on launch vehicles currently being studied, the need has arisen for the vehicle control augmentation that is provided by these flight controls. Aerodynamic flight control can also reduce engine gimbaling requirements, provide actuator failure protection, enhance crew safety, and increase vehicle reliability, and payload capability. In the Saturn era, NASA went to the Moon with 300 sq ft of aerodynamic surfaces on the Saturn V. Since those days, the wealth of smart materials and advanced composites that have been developed allow for the design of very lightweight, strong, and innovative launch vehicle flight control surfaces. This paper presents an overview of the advanced composites and smart materials that are directly applicable to launch vehicle control surfaces.

  12. Sliding Mode Control of the X-33 Vehicle in Launch Mode

    NASA Technical Reports Server (NTRS)

    Shtessel, Yuri; Jackson, Mark; Hall, Charles; Krupp, Don; Hendrix, N. Douglas

    1998-01-01

    The "nested" structure of the control system for the X33 vehicle in launch mode is developed. Employing backstopping concepts, the outer loop (guidance) and the Inner loop (rates) continuous sliding mode controllers are designed. Simulations of the 3-DOF model of the X33 launch vehicle showed an accurate, robust, de-coupled tracking performance.

  13. Elevator Sizing, Placement, and Control-Relevant Tradeoffs for Hypersonic Vehicles

    NASA Technical Reports Server (NTRS)

    Dickeson, Jeffrey J.; Rodriguez, Armando A.; Sridharan, Srikanth; Korad, Akshay

    2010-01-01

    Within this paper, control-relevant vehicle design concepts are examined using a widely used 3 DOF (plus flexibility) nonlinear model for the longitudinal dynamics of a generic carrot-shaped scramjet powered hypersonic vehicle. The impact of elevator size and placement on control-relevant static properties (e.g. level-flight trimmable region, trim controls, Angle of Attack (AOA), thrust margin) and dynamic properties (e.g. instability and right half plane zero associated with flight path angle) are examined. Elevator usage has been examine for a class of typical hypersonic trajectories.

  14. Engineering Social Justice into Traffic Control for Self-Driving Vehicles?

    PubMed

    Mladenovic, Milos N; McPherson, Tristram

    2016-08-01

    The convergence of computing, sensing, and communication technology will soon permit large-scale deployment of self-driving vehicles. This will in turn permit a radical transformation of traffic control technology. This paper makes a case for the importance of addressing questions of social justice in this transformation, and sketches a preliminary framework for doing so. We explain how new forms of traffic control technology have potential implications for several dimensions of social justice, including safety, sustainability, privacy, efficiency, and equal access. Our central focus is on efficiency and equal access as desiderata for traffic control design. We explain the limitations of conventional traffic control in meeting these desiderata, and sketch a preliminary vision for a next-generation traffic control tailored to address better the demands of social justice. One component of this vision is cooperative, hierarchically distributed self-organization among vehicles. Another component of this vision is a priority system enabling selection of priority levels by the user for each vehicle trip in the network, based on the supporting structure of non-monetary credits.

  15. Geochemical processes controlling water salinization in an irrigated basin in Spain: identification of natural and anthropogenic influence.

    PubMed

    Merchán, D; Auqué, L F; Acero, P; Gimeno, M J; Causapé, J

    2015-01-01

    Salinization of water bodies represents a significant risk in water systems. The salinization of waters in a small irrigated hydrological basin is studied herein through an integrated hydrogeochemical study including multivariate statistical analyses and geochemical modeling. The study zone has two well differentiated geologic materials: (i) Quaternary sediments of low salinity and high permeability and (ii) Tertiary sediments of high salinity and very low permeability. In this work, soil samples were collected and leaching experiments conducted on them in the laboratory. In addition, water samples were collected from precipitation, irrigation, groundwater, spring and surface waters. The waters show an increase in salinity from precipitation and irrigation water to ground- and, finally, surface water. The enrichment in salinity is related to the dissolution of soluble mineral present mainly in the Tertiary materials. Cation exchange, precipitation of calcite and, probably, incongruent dissolution of dolomite, have been inferred from the hydrochemical data set. Multivariate statistical analysis provided information about the structure of the data, differentiating the group of surface waters from the groundwaters and the salinization from the nitrate pollution processes. The available information was included in geochemical models in which hypothesis of consistency and thermodynamic feasibility were checked. The assessment of the collected information pointed to a natural control on salinization processes in the Lerma Basin with minimal influence of anthropogenic factors. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Dynamics and Control of Non-Smooth Systems with Applications to Supercavitating Vehicles

    DTIC Science & Technology

    2011-01-01

    ABSTRACT Title of dissertation: Dynamics and Control of Non-Smooth Systems with Applications to Supercavitating Vehicles Vincent Nguyen, Doctor of...relates to the dynamics of non-smooth vehicle systems, and in particular, supercavitating vehicles. These high-speed under- water vehicles are...Applications to Supercavitating Vehicles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK

  17. Orion Launch Abort Vehicle Attitude Control Motor Testing

    NASA Technical Reports Server (NTRS)

    Murphy, Kelly J.; Brauckmann, Gregory J.; Paschal, Keith B.; Chan, David T.; Walker, Eric L.; Foley, Robert; Mayfield, David; Cross, Jared

    2011-01-01

    Current Orion Launch Abort Vehicle (LAV) configurations use an eight-jet, solid-fueled Attitude Control Motor (ACM) to provide required vehicle control for all proposed abort trajectories. Due to the forward position of the ACM on the LAV, it is necessary to assess the effects of jet-interactions (JI) between the various ACM nozzle plumes and the external flow along the outside surfaces of the vehicle. These JI-induced changes in flight control characteristics must be accounted for in developing ACM operations and LAV flight characteristics. A test program to generate jet interaction aerodynamic increment data for multiple LAV configurations was conducted in the NASA Ames and NASA Langley Unitary Plan Wind Tunnels from August 2007 through December 2009. Using cold air as the simulant gas, powered subscale models were used to generate interaction data at subsonic, transonic, and supersonic test conditions. This paper presents an overview of the complete ACM JI experimental test program for Orion LAV configurations, highlighting ACM system modeling, nozzle scaling assumptions, experimental test techniques, and data reduction methodologies. Lessons learned are discussed, and sample jet interaction data are shown. These data, in conjunction with computational predictions, were used to create the ACM JI increments for all relevant flight databases.

  18. Launch Vehicle Control Center Architectures

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Epps, Amy; Woodruff, Van; Vachon, Michael Jacob; Monreal, Julio; Williams, Randall; McLaughlin, Tom

    2014-01-01

    This analysis is a survey of control center architectures of the NASA Space Launch System (SLS), United Launch Alliance (ULA) Atlas V and Delta IV, and the European Space Agency (ESA) Ariane 5. Each of these control center architectures have similarities in basic structure, and differences in functional distribution of responsibilities for the phases of operations: (a) Launch vehicles in the international community vary greatly in configuration and process; (b) Each launch site has a unique processing flow based on the specific configurations; (c) Launch and flight operations are managed through a set of control centers associated with each launch site, however the flight operations may be a different control center than the launch center; and (d) The engineering support centers are primarily located at the design center with a small engineering support team at the launch site.

  19. Hybrid adaptive ascent flight control for a flexible launch vehicle

    NASA Astrophysics Data System (ADS)

    Lefevre, Brian D.

    For the purpose of maintaining dynamic stability and improving guidance command tracking performance under off-nominal flight conditions, a hybrid adaptive control scheme is selected and modified for use as a launch vehicle flight controller. This architecture merges a model reference adaptive approach, which utilizes both direct and indirect adaptive elements, with a classical dynamic inversion controller. This structure is chosen for a number of reasons: the properties of the reference model can be easily adjusted to tune the desired handling qualities of the spacecraft, the indirect adaptive element (which consists of an online parameter identification algorithm) continually refines the estimates of the evolving characteristic parameters utilized in the dynamic inversion, and the direct adaptive element (which consists of a neural network) augments the linear feedback signal to compensate for any nonlinearities in the vehicle dynamics. The combination of these elements enables the control system to retain the nonlinear capabilities of an adaptive network while relying heavily on the linear portion of the feedback signal to dictate the dynamic response under most operating conditions. To begin the analysis, the ascent dynamics of a launch vehicle with a single 1st stage rocket motor (typical of the Ares 1 spacecraft) are characterized. The dynamics are then linearized with assumptions that are appropriate for a launch vehicle, so that the resulting equations may be inverted by the flight controller in order to compute the control signals necessary to generate the desired response from the vehicle. Next, the development of the hybrid adaptive launch vehicle ascent flight control architecture is discussed in detail. Alterations of the generic hybrid adaptive control architecture include the incorporation of a command conversion operation which transforms guidance input from quaternion form (as provided by NASA) to the body-fixed angular rate commands needed by the

  20. Vehicle anti-rollover control strategy based on load transferring rate

    NASA Astrophysics Data System (ADS)

    Dai, W. T.; Du, H. Q.; Zhang, L.

    2018-03-01

    When vehicles is drived on a low adhesion road or going on a high speed and sharp turn, it is prone to product some lateral stability problems, such as lateral sideslip or rollover. In order to improve the vehicle anti-rollover stability under these limited conditions, a SUV vehicle model with high mass center was built based on the software of CarSim and the rollover stability controller was designed using the static threshold value method for the lateral load transferring rate (LTR). The simulations are shown that the vehicle anti-rollover stability under limit conditions is improved using the SUV model.

  1. A model predictive speed tracking control approach for autonomous ground vehicles

    NASA Astrophysics Data System (ADS)

    Zhu, Min; Chen, Huiyan; Xiong, Guangming

    2017-03-01

    This paper presents a novel speed tracking control approach based on a model predictive control (MPC) framework for autonomous ground vehicles. A switching algorithm without calibration is proposed to determine the drive or brake control. Combined with a simple inverse longitudinal vehicle model and adaptive regulation of MPC, this algorithm can make use of the engine brake torque for various driving conditions and avoid high frequency oscillations automatically. A simplified quadratic program (QP) solving algorithm is used to reduce the computational time, and the approach has been applied in a 16-bit microcontroller. The performance of the proposed approach is evaluated via simulations and vehicle tests, which were carried out in a range of speed-profile tracking tasks. With a well-designed system structure, high-precision speed control is achieved. The system can robustly model uncertainty and external disturbances, and yields a faster response with less overshoot than a PI controller.

  2. The Role of Bolus Injection of Saline with Arm Elevation on Rocuronium onset Time: A Randomized Control Study

    PubMed Central

    Kulkarni, Malavika; Chuchendra, L. S.; Bhavya, P. J.

    2018-01-01

    Background: The onset time of neuromuscular blockade is a crucial time associated with the risk of hypoxia and pulmonary aspiration. Various strategies have been undertaken to shorten this onset time. Therefore, we investigated the effects of bolus of 20 ml saline followed by limb elevation after administration of rocuronium in a dose of 0.6 mg/kg to study the onset time. Methodology: Thirty patients were randomly allocated to the bolus saline group or control group. General anesthesia was induced and maintained with fentanyl and propofol. Rocuronium 0.6 mg/kg intravenous (IV) was administered followed by 20 ml saline bolus and limb elevation in the study group compared to administration of 0.6 mg/kg in a running drip only in the control. Onset of neuromuscular block was assessed by acceleromyography at the adductor pollicis muscle with train-of-four stimulation. Results: The lag time was shorter in bolus group (34 s median) than in control group (45 s median), P < 0.017. The onset time was shorter in bolus group (55 s median) than in control group (110 s median), P < 0.001. The T1 recovery to 25% was longer in bolus group (42 min median) than in control group (39 min median) which was statistically not significant. Conclusion: Rocuronium 0.6 mg/kg IV followed by bolus 20 ml saline and concomitant limb elevation resulted in shorter lag time, faster onset of neuromuscular blockade, good intubating conditions without prolonging clinical duration of action when compared to the control. PMID:29628555

  3. Multimodal control of sensors on multiple simulated unmanned vehicles.

    PubMed

    Baber, C; Morin, C; Parekh, M; Cahillane, M; Houghton, R J

    2011-09-01

    The use of multimodal (speech plus manual) control of the sensors on combinations of one, two, three or five simulated unmanned vehicles (UVs) is explored. Novice controllers of simulated UVs complete a series of target checking tasks. Two experiments compare speech and gamepad control for one, two, three or five UVs in a simulated environment. Increasing the number of UVs has an impact on subjective rating of workload (measured by NASA-Task Load Index), particularly when moving from one to three UVs. Objective measures of performance showed that the participants tended to issue fewer commands as the number of vehicles increased (when using the gamepad control), but, while performance with a single UV was superior to that of multiple UVs, there was little difference across two, three or five UVs. Participants with low spatial ability (measured by the Object Perspectives Test) showed an increase in time to respond to warnings when controlling five UVs. Combining speech with gamepad control of sensors on UVs leads to superior performance on a secondary (respond-to-warnings) task (implying a reduction in demand) and use of fewer commands on primary (move-sensors and classify-target) tasks (implying more efficient operation). STATEMENT OF RELEVANCE: Benefits of multimodal control for unmanned vehicles are demonstrated. When controlling sensors on multiple UVs, participants with low spatial orientation scores have problems. It is proposed that the findings of these studies have implications for selection of UV operators and suggests that future UV workstations could benefit from multimodal control.

  4. Tracking Control and System Development for Laser-Driven Micro-Vehicles

    NASA Astrophysics Data System (ADS)

    Kajiwara, Itsuro; Hoshino, Kentaro; Hara, Shinji; Shiokata, Daisuke; Yabe, Takashi

    The purpose of this paper is to design a control system for an integrated laser propulsion/tracking system to achieve continuous motion and control of laser-driven micro-vehicles. Laser propulsion is significant in achieving miniature and light micro-vehicles. A laser-driven micro-airplane has been studied using a paper airplane and YAG laser, resulting in successful gliding of the airplane. High-performance laser tracking control is required to achieve continuous flight. This paper presents a control design strategy based on the generalized Kalman-Yakubovic-Popov lemma to achieve this requirement. Experiments have been carried out to evaluate the performance of the integrated laser propulsion/tracking system.

  5. Control of Sulfide Production in High Salinity Bakken Shale Oil Reservoirs by Halophilic Bacteria Reducing Nitrate to Nitrite.

    PubMed

    An, Biwen A; Shen, Yin; Voordouw, Gerrit

    2017-01-01

    Microbial communities in shale oil fields are still poorly known. We obtained samples of injection, produced and facility waters from a Bakken shale oil field in Saskatchewan, Canada with a resident temperature of 60°C. The injection water had a lower salinity (0.7 Meq of NaCl) than produced or facility waters (0.6-3.6 Meq of NaCl). Salinities of the latter decreased with time, likely due to injection of low salinity water, which had 15-30 mM sulfate. Batch cultures of field samples showed sulfate-reducing and nitrate-reducing bacteria activities at different salinities (0, 0.5, 0.75, 1.0, 1.5, and 2.5 M NaCl). Notably, at high salinity nitrite accumulated, which was not observed at low salinity, indicating potential for nitrate-mediated souring control at high salinity. Continuous culture chemostats were established in media with volatile fatty acids (a mixture of acetate, propionate and butyrate) or lactate as electron donor and nitrate or sulfate as electron acceptor at 0.5 to 2.5 M NaCl. Microbial community analyses of these cultures indicated high proportions of Halanaerobium, Desulfovermiculus, Halomonas , and Marinobacter in cultures at 2.5 M NaCl, whereas Desulfovibrio, Geoalkalibacter , and Dethiosulfatibacter were dominant at 0.5 M NaCl. Use of bioreactors to study the effect of nitrate injection on sulfate reduction showed that accumulation of nitrite inhibited SRB activity at 2.5 M but not at 0.5 M NaCl. High proportions of Halanaerobium and Desulfovermiculus were found at 2.5 M NaCl in the absence of nitrate, whereas high proportions of Halomonas and no SRB were found in the presence of nitrate. A diverse microbial community dominated by the SRB Desulfovibrio was observed at 0.5 M NaCl both in the presence and absence of nitrate. Our results suggest that nitrate injection can prevent souring provided that the salinity is maintained at a high level. Thus, reinjection of high salinity produced water amended with nitrate maybe be a cost effective method

  6. Analysis and Design of Launch Vehicle Flight Control Systems

    NASA Technical Reports Server (NTRS)

    Wie, Bong; Du, Wei; Whorton, Mark

    2008-01-01

    This paper describes the fundamental principles of launch vehicle flight control analysis and design. In particular, the classical concept of "drift-minimum" and "load-minimum" control principles is re-examined and its performance and stability robustness with respect to modeling uncertainties and a gimbal angle constraint is discussed. It is shown that an additional feedback of angle-of-attack or lateral acceleration can significantly improve the overall performance and robustness, especially in the presence of unexpected large wind disturbance. Non-minimum-phase structural filtering of "unstably interacting" bending modes of large flexible launch vehicles is also shown to be effective and robust.

  7. Precessional control of Sr ratios in marginal basins during the Messinian Salinity Crisis?

    NASA Astrophysics Data System (ADS)

    Topper, R. P. M.; Lugli, S.; Manzi, V.; Roveri, M.; Meijer, P. Th.

    2014-05-01

    Based on 87Sr/86Sr data of the Primary Lower Gypsum (PLG) deposits in the Vena del Gesso basin—a marginal basin of the Mediterranean during the Messinian Salinity Crisis—a correlation between 87Sr/86Sr values and precessional forcing has recently been proposed but not yet confirmed. In this study, a box model is set up to represent the Miocene Mediterranean deep basin and a connected marginal basin. Measurements of 87Sr/86Sr in the Vena del Gesso and estimated salinity extrema are used to constrain model results. In an extensive analysis with this model, we assess whether coeval 87Sr/86Sr and salinity fluctuations could have been forced by precession-driven changes in the fresh water budget. A comprehensive set of the controlling parameters is examined to assess the conditions under which precession-driven 87Sr/86Sr variations occur and to determine the most likely setting for PLG formation. Model results show that precession-driven 87Sr/86Sr and salinity fluctuations in marginal basins are produced in settings within a large range of marginal basin sizes, riverine strontium characteristics, amplitudes of precessional fresh water budget variation, and average fresh water budgets of both the marginal and deep basin. PLG deposition most likely occurred when the Atlantic-Mediterranean connection was restricted, and the average fresh water budget in the Mediterranean was significantly less negative than at present day. Considering the large range of settings in which salinities and 87Sr/86Sr fluctuate on a precessional timescale, 87Sr/86Sr variations are expected to be a common feature in PLG deposits in marginal basins of the Mediterranean.

  8. Crew Exploration Vehicle Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard; Carrasquillo, Robyn; Cross, Cindy; Peterson, Laurie; Tuan, George

    2009-01-01

    The Orion Crew Exploration Vehicle (CEV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. The CEV is being developed to transport the crew safely from the Earth to the Moon and back again. This year, the vehicle continued to go through design refinements to reduce weight, meet requirements, and operate reliably. Preliminary Design Review was performed and long lead procurement items were started. The design of the Orion Environmental Control and Life Support (ECLS) system, which includes the life support and active thermal control systems, is progressing through the design stage into manufacturing. This paper covers the Orion ECLS development from April 2009 to April 2010.

  9. Crew Exploration Vehicle Environmental Control and Life Support Ddevelopment Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Carrasquillo, Robyn; Cross, Cynthia d.; Rains, Ed; Tuan, George C.

    2010-01-01

    The Orion Crew Exploration Vehicle (CEV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. The CEV is being developed to transport the crew safely from the Earth to the Moon and back again. This year, the vehicle continued to go through design refinements to reduce weight, meet requirements, and operate reliably. Preliminary Design Review was performed and long lead procurement items were started. The design of the Orion Environmental Control and Life Support (ECLS) system, which includes the life support and active thermal control systems, is progressing through the design stage into manufacturing. This paper covers the Orion ECLS development from April 2009 to April 2010

  10. Hypersonic vehicle model and control law development using H(infinity) and micron synthesis

    NASA Astrophysics Data System (ADS)

    Gregory, Irene M.; Chowdhry, Rajiv S.; McMinn, John D.; Shaughnessy, John D.

    1994-10-01

    The control system design for a Single Stage To Orbit (SSTO) air breathing vehicle will be central to a successful mission because a precise ascent trajectory will preserve narrow payload margins. The air breathing propulsion system requires the vehicle to fly roughly halfway around the Earth through atmospheric turbulence. The turbulence, the high sensitivity of the propulsion system to inlet flow conditions, the relatively large uncertainty of the parameters characterizing the vehicle, and continuous acceleration make the problem especially challenging. Adequate stability margins must be provided without sacrificing payload mass since payload margins are critical. Therefore, a multivariable control theory capable of explicitly including both uncertainty and performance is needed. The H(infinity) controller in general provides good robustness but can result in conservative solutions for practical problems involving structured uncertainty. Structured singular value mu framework for analysis and synthesis is potentially much less conservative and hence more appropriate for problems with tight margins. An SSTO control system requires: highly accurate tracking of velocity and altitude commands while limiting angle-of-attack oscillations, minimized control power usage, and a stabilized vehicle when atmospheric turbulence and system uncertainty are present. The controller designs using H(infinity) and mu-synthesis procedures were compared. An integrated flight/propulsion dynamic mathematical model of a conical accelerator vehicle was linearized as the vehicle accelerated through Mach 8. Vehicle acceleration through the selected flight condition gives rise to parametric variation that was modeled as a structured uncertainty. The mu-analysis approach was used in the frequency domain to conduct controller analysis and was confirmed by time history plots. Results demonstrate the inherent advantages of the mu framework for this class of problems.

  11. Hypersonic vehicle model and control law development using H(infinity) and micron synthesis

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.; Chowdhry, Rajiv S.; Mcminn, John D.; Shaughnessy, John D.

    1994-01-01

    The control system design for a Single Stage To Orbit (SSTO) air breathing vehicle will be central to a successful mission because a precise ascent trajectory will preserve narrow payload margins. The air breathing propulsion system requires the vehicle to fly roughly halfway around the Earth through atmospheric turbulence. The turbulence, the high sensitivity of the propulsion system to inlet flow conditions, the relatively large uncertainty of the parameters characterizing the vehicle, and continuous acceleration make the problem especially challenging. Adequate stability margins must be provided without sacrificing payload mass since payload margins are critical. Therefore, a multivariable control theory capable of explicitly including both uncertainty and performance is needed. The H(infinity) controller in general provides good robustness but can result in conservative solutions for practical problems involving structured uncertainty. Structured singular value mu framework for analysis and synthesis is potentially much less conservative and hence more appropriate for problems with tight margins. An SSTO control system requires: highly accurate tracking of velocity and altitude commands while limiting angle-of-attack oscillations, minimized control power usage, and a stabilized vehicle when atmospheric turbulence and system uncertainty are present. The controller designs using H(infinity) and mu-synthesis procedures were compared. An integrated flight/propulsion dynamic mathematical model of a conical accelerator vehicle was linearized as the vehicle accelerated through Mach 8. Vehicle acceleration through the selected flight condition gives rise to parametric variation that was modeled as a structured uncertainty. The mu-analysis approach was used in the frequency domain to conduct controller analysis and was confirmed by time history plots. Results demonstrate the inherent advantages of the mu framework for this class of problems.

  12. Control techniques for an automated mixed traffic vehicle

    NASA Technical Reports Server (NTRS)

    Meisenholder, G. W.; Johnston, A. R.

    1977-01-01

    The paper describes an automated mixed traffic vehicle (AMTV), a driverless low-speed tram designed to operate in mixed pedestrian and vehicular traffic. The vehicle is a six-passenger electric tram equipped with sensing and control which permit it to function on existing streets in an automatic mode. The design includes established wire-following techniques for steering and near-IR headway sensors. A 7-mph cruise speed is reduced to 2 mph or a complete stop in response to sensor (or passenger) inputs. The AMTV performance is evaluated by operation on a loop route and by simulation. Some necessary improvements involving sensors, sensor pattern, use of an audible signal, and control lag are discussed. It is suggested that appropriate modifications will eliminate collision incidents.

  13. Rotorcraft control system design for uncertain vehicle dynamics using quantitative feedback theory

    NASA Technical Reports Server (NTRS)

    Hess, R. A.

    1994-01-01

    Quantitative Feedback Theory describes a frequency-domain technique for the design of multi-input, multi-output control systems which must meet time or frequency domain performance criteria when specified uncertainty exists in the linear description of the vehicle dynamics. This theory is applied to the design of the longitudinal flight control system for a linear model of the BO-105C rotorcraft. Uncertainty in the vehicle model is due to the variation in the vehicle dynamics over a range of airspeeds from 0-100 kts. For purposes of exposition, the vehicle description contains no rotor or actuator dynamics. The design example indicates the manner in which significant uncertainty exists in the vehicle model. The advantage of using a sequential loop closure technique to reduce the cost of feedback is demonstrated by example.

  14. Advanced Cell-Level Control for Extending Electric Vehicle Battery Pack Lifetime

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rehman, M. Muneeb Ur; Zhang, Fan; Evzelman, Michael

    A cell-level control approach for electric vehicle battery packs is presented that enhances traditional battery balancing goals to not only provide cell balancing but also achieve significant pack lifetime extension. These goals are achieved by applying a new life-prognostic based control algorithm that biases individual cells differently based on their state of charge, capacity and internal resistance. The proposed life control approach reduces growth in capacity mismatch typically seen in large battery packs over life while optimizing usable energy of the pack. The result is a longer lifetime of the overall pack and a more homogeneous distribution of cell capacitiesmore » at the end of the first life for vehicle applications. Active cell balancing circuits and associated algorithms are used to accomplish the cell-level life extension objectives. This paper presents details of the cell-level control approach, selection and design of the active balancing system, and low-complexity state-of-charge, capacity, and series-resistance estimation algorithms. A laboratory prototype is used to demonstrate the proposed control approach. The prototype consists of twenty-one 25 Ah Panasonic lithium-Ion NMC battery cells from a commercial electric vehicle and an integrated BMS/DC-DC system that provides 750 W to the vehicle low voltage auxiliary loads.« less

  15. Advanced Cell-Level Control for Extending Electric Vehicle Battery Pack Lifetime

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rehman, M. Muneeb Ur; Zhang, Fan; Evzelman, Michael

    2017-02-16

    A cell-level control approach for electric vehicle battery packs is presented that enhances traditional battery balancing goals to not only provide cell balancing but also achieve significant pack lifetime extension. These goals are achieved by applying a new life-prognostic based control algorithm that biases individual cells differently based on their state of charge, capacity and internal resistance. The proposed life control approach reduces growth in capacity mismatch typically seen in large battery packs over life while optimizing usable energy of the pack. The result is a longer lifetime of the overall pack and a more homogeneous distribution of cell capacitiesmore » at the end of the first life for vehicle applications. Active cell balancing circuits and associated algorithms are used to accomplish the cell-level life extension objectives. This paper presents details of the cell-level control approach, selection and design of the active balancing system, and low-complexity state-of-charge, capacity, and series-resistance estimation algorithms. A laboratory prototype is used to demonstrate the proposed control approach. The prototype consists of twenty-one 25 Ah Panasonic lithium-Ion NMC battery cells from a commercial electric vehicle and an integrated BMS/DC-DC system that provides 750 W to the vehicle low voltage auxiliary loads.« less

  16. A novel direct yaw moment controller for in-wheel motor electric vehicles

    NASA Astrophysics Data System (ADS)

    Chen, Yuhang; Hedrick, J. Karl; Guo, Konghui

    2013-06-01

    A novel direct yaw moment controller is developed in this paper. A hierarchical control architecture is adopted in the controller design. In the upper controller, a driver model and a vehicle model are used to obtain the driver's intention and the vehicle states, respectively. The upper controller determines the desired yaw moment by means of sliding mode control. The lower controller distributes differential longitudinal forces according to the desired yaw moment. A nonlinear tyre model, 'UniTire', is utilised to develop the novel distribution strategy and the control boundary.

  17. Optimisation of active suspension control inputs for improved vehicle handling performance

    NASA Astrophysics Data System (ADS)

    Čorić, Mirko; Deur, Joško; Kasać, Josip; Tseng, H. Eric; Hrovat, Davor

    2016-11-01

    Active suspension is commonly considered under the framework of vertical vehicle dynamics control aimed at improvements in ride comfort. This paper uses a collocation-type control variable optimisation tool to investigate to which extent the fully active suspension (FAS) application can be broaden to the task of vehicle handling/cornering control. The optimisation approach is firstly applied to solely FAS actuator configurations and three types of double lane-change manoeuvres. The obtained optimisation results are used to gain insights into different control mechanisms that are used by FAS to improve the handling performance in terms of path following error reduction. For the same manoeuvres the FAS performance is compared with the performance of different active steering and active differential actuators. The optimisation study is finally extended to combined FAS and active front- and/or rear-steering configurations to investigate if they can use their complementary control authorities (over the vertical and lateral vehicle dynamics, respectively) to further improve the handling performance.

  18. Historic and future trends of vehicle emissions in Beijing, 1998-2020: A policy assessment for the most stringent vehicle emission control program in China

    NASA Astrophysics Data System (ADS)

    Zhang, Shaojun; Wu, Ye; Wu, Xiaomeng; Li, Mengliang; Ge, Yunshan; Liang, Bin; Xu, Yueyun; Zhou, Yu; Liu, Huan; Fu, Lixin; Hao, Jiming

    2014-06-01

    As a pioneer in controlling vehicle emissions within China, Beijing released the Clean Air Action Plan 2013-2017 document in August 2013 to improve its urban air quality. It has put forward this plan containing the most stringent emission control policies and strategies to be adopted for on-road vehicles of Beijing. This paper estimates the historic and future trends and uncertainties in vehicle emissions of Beijing from 1998 to 2020 by applying a new emission factor model for the Beijing vehicle fleet (EMBEV). Our updated results show that total emissions of CO, THC, NOx and PM2.5 from the Beijing vehicle fleet are 507 (395-819) kt, 59.1 (41.2-90.5) kt, 74.7 (54.9-103.9) kt and 2.69 (1.91-4.17) kt, respectively, at a 95% confidence level. This represents significant reductions of 58%, 59%, 31% and 62%, respectively, relative to the total vehicle emissions in 1998. The past trends clearly posed a challenge to NOx emission mitigation for the Beijing vehicle fleet, especially in light of those increasing NOx emissions from heavy-duty diesel vehicles (HDDVs) which have partly offset the reduction benefit from light-duty gasoline vehicles (LDGVs). Because of recently announced vehicle emission controls to be adopted in Beijing, including tighter emissions standards, limitations on vehicle growth by more stringent license control, promotion of alternative fuel technologies (e.g., natural gas) and the scrappage of older vehicles, estimated vehicle emissions in Beijing will continue to be mitigated by 74% of CO, 68% of THC, 56% of NOx and 72% of PM2.5 in 2020 compared to 2010 levels. Considering that many of the megacities in China are facing tremendous pressures to mitigate emissions from on-road vehicles, our assessment will provide a timely case study of significance for policy-makers in China.

  19. A Review of Control Strategy of the Large-scale of Electric Vehicles Charging and Discharging Behavior

    NASA Astrophysics Data System (ADS)

    Kong, Lingyu; Han, Jiming; Xiong, Wenting; Wang, Hao; Shen, Yaqi; Li, Ying

    2017-05-01

    Large scale access of electric vehicles will bring huge challenges to the safe operation of the power grid, and it’s important to control the charging and discharging of the electric vehicle. First of all, from the electric quality and network loss, this paper points out the influence on the grid caused by electric vehicle charging behaviour. Besides, control strategy of electric vehicle charging and discharging has carried on the induction and the summary from the direct and indirect control. Direct control strategy means control the electric charging behaviour by controlling its electric vehicle charging and discharging power while the indirect control strategy by means of controlling the price of charging and discharging. Finally, for the convenience of the reader, this paper also proposed a complete idea of the research methods about how to study the control strategy, taking the adaptability and possibility of failure of electric vehicle control strategy into consideration. Finally, suggestions on the key areas for future research are put up.

  20. Orion Multi Purpose Crew Vehicle Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Cross, Cynthia D.; Carrasquillo, Robyn; Rains, George Edward

    2012-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely from the Earth beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in 2014. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the components which are on EFT1 which includes pressure control and active thermal control systems, is progressing through the design stage into manufacturing. Additional development work was done to keep the remaining component progressing towards implementation for a flight tests in 2017 and in 2020. This paper covers the Orion ECLS development from April 2011 to April 2012.

  1. Air-breathing hypersonic vehicle guidance and control studies; An integrated trajectory/control analysis methodology: Phase 1

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1991-01-01

    A tool which generates optimal trajectory/control histories in an integrated manner is generically adapted to the treatment of single-stage-to-orbit air-breathing hypersonic vehicles. The methodology is implemented as a two point boundary value problem solution technique. Its use permits an assessment of an entire near-minimum-fuel trajectory and desired control strategy from takeoff to orbit while satisfying physically derived inequality constraints and while achieving efficient propulsive mode phasing. A simpler analysis strategy that partitions the trajectory into several boundary condition matched segments is also included to construct preliminary trajectory and control history representations with less computational burden than is required for the overall flight profile assessment. A demonstration was accomplished using a tabulated example (winged-cone accelerator) vehicle model that is combined with a newly developed multidimensional cubic spline data smoothing routine. A constrained near-fuel-optimal trajectory, imposing a dynamic pressure limit of 1000 psf, was developed from horizontal takeoff to 20,000 ft/sec relative air speed while aiming for a polar orbit. Previously unspecified propulsive discontinuities were located. Flight regimes demanding rapid attitude changes were identified, dictating control effector and closed-loop controller authority was ascertained after evaluating effector use for vehicle trim. Also, inadequacies in vehicle model representations and specific subsystem models with insufficient fidelity were determined based on unusual control characteristics and/or excessive sensitivity to uncertainty.

  2. Effects of Soil Salinity on the Expression of Bt Toxin (Cry1Ac) and the Control Efficiency of Helicoverpa armigera in Field-Grown Transgenic Bt Cotton.

    PubMed

    Luo, Jun-Yu; Zhang, Shuai; Peng, Jun; Zhu, Xiang-Zhen; Lv, Li-Min; Wang, Chun-Yi; Li, Chun-Hua; Zhou, Zhi-Guo; Cui, Jin-Jie

    2017-01-01

    An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels.

  3. Effects of Soil Salinity on the Expression of Bt Toxin (Cry1Ac) and the Control Efficiency of Helicoverpa armigera in Field-Grown Transgenic Bt Cotton

    PubMed Central

    Luo, Jun-Yu; Zhang, Shuai; Peng, Jun; Zhu, Xiang-Zhen; Lv, Li-Min; Wang, Chun-Yi; Li, Chun-Hua; Zhou, Zhi-Guo; Cui, Jin-Jie

    2017-01-01

    An increasing area of transgenic Bacillus thuringiensis (Bt) cotton is being planted in saline-alkaline soil in China. The Bt protein level in transgenic cotton plants and its control efficiency can be affected by abiotic stress, including high temperature, water deficiency and other factors. However, how soil salinity affects the expression of Bt protein, thus influencing the control efficiency of Bt cotton against the cotton bollworm (CBW) Helicoverpa armigera (Hübner) in the field, is poorly understood. Our objective in the present study was to investigate the effects of soil salinity on the expression of Bt toxin (Cry1Ac) and the control efficiency of Helicoverpa armigera in field-grown transgenic Bt cotton using three natural saline levels (1.15 dS m-1 [low soil-salinity], 6.00 dS m-1 [medium soil-salinity] and 11.46 dS m-1 [high soil-salinity]). We found that the Bt protein content in the transgenic Bt cotton leaves and the insecticidal activity of Bt cotton against CBW decreased with the increasing soil salinity in laboratory experiments during the growing season. The Bt protein content of Bt cotton leaves in the laboratory were negatively correlated with the salinity level. The CBW populations were highest on the Bt cotton grown in medium-salinity soil instead of the high-salinity soil in field conditions. A possible mechanism may be that the relatively high-salinity soil changed the plant nutritional quality or other plant defensive traits. The results from this study may help to identify more appropriate practices to control CBW in Bt cotton fields with different soil salinity levels. PMID:28099508

  4. Alleviation of the effects of saline-alkaline stress on maize seedlings by regulation of active oxygen metabolism by Trichoderma asperellum.

    PubMed

    Fu, Jian; Liu, Zhihua; Li, Zuotong; Wang, Yufeng; Yang, Kejun

    2017-01-01

    This study investigated the influence of Trichoderma asperellum on active oxygen production in maize seedlings under saline-alkaline stress conditions. Two maize cultivars were tested: 'Jiangyu 417' ('JY417'), which can tolerate saline-alkaline stress; and, 'Xianyu 335' ('XY335'), which is sensitive to saline-alkaline stress. The seedlings were grown on natural saline-alkaline soil (pH 9.30) in plastic pots. To each liter of saline-alkaline soil, 200 mL of T. asperellum spore suspension was applied; three fungal suspensions were used, namely, 1 × 103, 1 × 106, and 1 × 109 spores/L. A control with only the vehicle applied was also established, along with a second control in which untreated meadow soil (pH 8.23) was used. Root and leaf samples were collected when the seedlings had three heart-shaped leaves and the fourth was in the developmental phase. Physical and biochemical parameters related to oxidation resistance were assessed. The results indicated that the 'JY417' and 'XY335' seedlings showed different degrees of oxidative damage and differences in their antioxidant defense systems under saline-alkaline stress. As the spore density of the fungal suspension increased, the K+ and Ca2+ contents in the seedlings increased, but Na+ content decreased. Moreover, fungal treatment promoted the synthesis or accumulation of osmolytes, which enhanced the water absorbing capacity of the cells, increased antioxidant enzyme activities, enhanced the content of non-enzyme antioxidants, and reduced the accumulation of reactive oxygen species. Fungal treatment alleviated oxidative damage caused by the saline-alkaline stress in roots and leaves of the seedlings. The application of T. asperellum overcame the inhibitory effect of saline-alkaline soil stress on the growth of maize seedlings. In the present experiment, application with 1 × 109 spores/L gave the optimal results.

  5. Vehicle Guidance and Control Along Circular Trajectories

    DTIC Science & Technology

    1992-09-01

    the line of sight, while Chism [2] studied a cross track error based control law. Hawkinson [3] extended the results to the multiple input case when...Thesis, Naval Postgraduate School, Monterey, California, June. 2. Chism , S., (1990) "Robust path tracking of autonomous underwater vehicles using sliding

  6. Robust H∞ output-feedback control for path following of autonomous ground vehicles

    NASA Astrophysics Data System (ADS)

    Hu, Chuan; Jing, Hui; Wang, Rongrong; Yan, Fengjun; Chadli, Mohammed

    2016-03-01

    This paper presents a robust H∞ output-feedback control strategy for the path following of autonomous ground vehicles (AGVs). Considering the vehicle lateral velocity is usually hard to measure with low cost sensor, a robust H∞ static output-feedback controller based on the mixed genetic algorithms (GA)/linear matrix inequality (LMI) approach is proposed to realize the path following without the information of the lateral velocity. The proposed controller is robust to the parametric uncertainties and external disturbances, with the parameters including the tire cornering stiffness, vehicle longitudinal velocity, yaw rate and road curvature. Simulation results based on CarSim-Simulink joint platform using a high-fidelity and full-car model have verified the effectiveness of the proposed control approach.

  7. Vehicle height and posture control of the electronic air suspension system using the hybrid system approach

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoqiang; Cai, Yingfeng; Chen, Long; Liu, Yanling; Wang, Shaohua

    2016-03-01

    The electronic air suspension (EAS) system can improve ride comfort, fuel economy and handling safety of vehicles by adjusting vehicle height. This paper describes the development of a novel controller using the hybrid system approach to adjust the vehicle height (height control) and to regulate the roll and pitch angles of the vehicle body during the height adjustment process (posture control). The vehicle height adjustment system of EAS poses challenging hybrid control problems, since it features different discrete modes of operation, where each mode has an associated linear continuous-time dynamic. In this paper, we propose a novel approach to the modelling and controller design problem for the vehicle height adjustment system of EAS. The system model is described firstly in the hybrid system description language (HYSDEL) to obtain a mixed logical dynamical (MLD) hybrid model. For the resulting model, a hybrid model predictive controller is tuned to improve the vehicle height and posture tracking accuracy and to achieve the on-off statuses direct control of solenoid valves. The effectiveness and performance of the proposed approach are demonstrated by simulations and actual vehicle tests.

  8. Guidance and Control strategies for aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Hibey, J. L.; Naidu, D. S.; Charalambous, C. D.

    1989-01-01

    A neighboring optimal guidance scheme was devised for a nonlinear dynamic system with stochastic inputs and perfect measurements as applicable to fuel optimal control of an aeroassisted orbital transfer vehicle. For the deterministic nonlinear dynamic system describing the atmospheric maneuver, a nominal trajectory was determined. Then, a neighboring, optimal guidance scheme was obtained for open loop and closed loop control configurations. Taking modelling uncertainties into account, a linear, stochastic, neighboring optimal guidance scheme was devised. Finally, the optimal trajectory was approximated as the sum of the deterministic nominal trajectory and the stochastic neighboring optimal solution. Numerical results are presented for a typical vehicle. A fuel-optimal control problem in aeroassisted noncoplanar orbital transfer is also addressed. The equations of motion for the atmospheric maneuver are nonlinear and the optimal (nominal) trajectory and control are obtained. In order to follow the nominal trajectory under actual conditions, a neighboring optimum guidance scheme is designed using linear quadratic regulator theory for onboard real-time implementation. One of the state variables is used as the independent variable in reference to the time. The weighting matrices in the performance index are chosen by a combination of a heuristic method and an optimal modal approach. The necessary feedback control law is obtained in order to minimize the deviations from the nominal conditions.

  9. Optimization and Control of Cyber-Physical Vehicle Systems

    PubMed Central

    Bradley, Justin M.; Atkins, Ella M.

    2015-01-01

    A cyber-physical system (CPS) is composed of tightly-integrated computation, communication and physical elements. Medical devices, buildings, mobile devices, robots, transportation and energy systems can benefit from CPS co-design and optimization techniques. Cyber-physical vehicle systems (CPVSs) are rapidly advancing due to progress in real-time computing, control and artificial intelligence. Multidisciplinary or multi-objective design optimization maximizes CPS efficiency, capability and safety, while online regulation enables the vehicle to be responsive to disturbances, modeling errors and uncertainties. CPVS optimization occurs at design-time and at run-time. This paper surveys the run-time cooperative optimization or co-optimization of cyber and physical systems, which have historically been considered separately. A run-time CPVS is also cooperatively regulated or co-regulated when cyber and physical resources are utilized in a manner that is responsive to both cyber and physical system requirements. This paper surveys research that considers both cyber and physical resources in co-optimization and co-regulation schemes with applications to mobile robotic and vehicle systems. Time-varying sampling patterns, sensor scheduling, anytime control, feedback scheduling, task and motion planning and resource sharing are examined. PMID:26378541

  10. Optimization and Control of Cyber-Physical Vehicle Systems.

    PubMed

    Bradley, Justin M; Atkins, Ella M

    2015-09-11

    A cyber-physical system (CPS) is composed of tightly-integrated computation, communication and physical elements. Medical devices, buildings, mobile devices, robots, transportation and energy systems can benefit from CPS co-design and optimization techniques. Cyber-physical vehicle systems (CPVSs) are rapidly advancing due to progress in real-time computing, control and artificial intelligence. Multidisciplinary or multi-objective design optimization maximizes CPS efficiency, capability and safety, while online regulation enables the vehicle to be responsive to disturbances, modeling errors and uncertainties. CPVS optimization occurs at design-time and at run-time. This paper surveys the run-time cooperative optimization or co-optimization of cyber and physical systems, which have historically been considered separately. A run-time CPVS is also cooperatively regulated or co-regulated when cyber and physical resources are utilized in a manner that is responsive to both cyber and physical system requirements. This paper surveys research that considers both cyber and physical resources in co-optimization and co-regulation schemes with applications to mobile robotic and vehicle systems. Time-varying sampling patterns, sensor scheduling, anytime control, feedback scheduling, task and motion planning and resource sharing are examined.

  11. From Antarctica to space: Use of telepresence and virtual reality in control of remote vehicles

    NASA Technical Reports Server (NTRS)

    Stoker, Carol; Hine, Butler P., III; Sims, Michael; Rasmussen, Daryl; Hontalas, Phil; Fong, Terrence W.; Steele, Jay; Barch, Don; Andersen, Dale; Miles, Eric

    1994-01-01

    In the Fall of 1993, NASA Ames deployed a modified Phantom S2 Remotely-Operated underwater Vehicle (ROV) into an ice-covered sea environment near McMurdo Science Station, Antarctica. This deployment was part of the antarctic Space Analog Program, a joint program between NASA and the National Science Foundation to demonstrate technologies relevant for space exploration in realistic field setting in the Antarctic. The goal of the mission was to operationally test the use of telepresence and virtual reality technology in the operator interface to a remote vehicle, while performing a benthic ecology study. The vehicle was operated both locally, from above a dive hole in the ice through which it was launched, and remotely over a satellite communications link from a control room at NASA's Ames Research Center. Local control of the vehicle was accomplished using the standard Phantom control box containing joysticks and switches, with the operator viewing stereo video camera images on a stereo display monitor. Remote control of the vehicle over the satellite link was accomplished using the Virtual Environment Vehicle Interface (VEVI) control software developed at NASA Ames. The remote operator interface included either a stereo display monitor similar to that used locally or a stereo head-mounted head-tracked display. The compressed video signal from the vehicle was transmitted to NASA Ames over a 768 Kbps satellite channel. Another channel was used to provide a bi-directional Internet link to the vehicle control computer through which the command and telemetry signals traveled, along with a bi-directional telephone service. In addition to the live stereo video from the satellite link, the operator could view a computer-generated graphic representation of the underwater terrain, modeled from the vehicle's sensors. The virtual environment contained an animate graphic model of the vehicle which reflected the state of the actual vehicle, along with ancillary information such

  12. Optimal strategies for the control of autonomous vehicles in data assimilation

    NASA Astrophysics Data System (ADS)

    McDougall, D.; Moore, R. O.

    2017-08-01

    We propose a method to compute optimal control paths for autonomous vehicles deployed for the purpose of inferring a velocity field. In addition to being advected by the flow, the vehicles are able to effect a fixed relative speed with arbitrary control over direction. It is this direction that is used as the basis for the locally optimal control algorithm presented here, with objective formed from the variance trace of the expected posterior distribution. We present results for linear flows near hyperbolic fixed points.

  13. Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 2: Noise Control

    NASA Technical Reports Server (NTRS)

    Hubbard, Harvey H. (Editor)

    1991-01-01

    Flight vehicles and the underlying concepts of noise generation, noise propagation, noise prediction, and noise control are studied. This volume includes those chapters that relate to flight vehicle noise control and operations: human response to aircraft noise; atmospheric propagation; theoretical models for duct acoustic propagation and radiation; design and performance of duct acoustic treatment; jet noise suppression; interior noise; flyover noise measurement and prediction; and quiet aircraft design and operational characteristics.

  14. Tire-road friction estimation and traction control strategy for motorized electric vehicle.

    PubMed

    Jin, Li-Qiang; Ling, Mingze; Yue, Weiqiang

    2017-01-01

    In this paper, an optimal longitudinal slip ratio system for real-time identification of electric vehicle (EV) with motored wheels is proposed based on the adhesion between tire and road surface. First and foremost, the optimal longitudinal slip rate torque control can be identified in real time by calculating the derivative and slip rate of the adhesion coefficient. Secondly, the vehicle speed estimation method is also brought. Thirdly, an ideal vehicle simulation model is proposed to verify the algorithm with simulation, and we find that the slip ratio corresponds to the detection of the adhesion limit in real time. Finally, the proposed strategy is applied to traction control system (TCS). The results showed that the method can effectively identify the state of wheel and calculate the optimal slip ratio without wheel speed sensor; in the meantime, it can improve the accelerated stability of electric vehicle with traction control system (TCS).

  15. Crew exploration vehicle (CEV) attitude control using a neural-immunology/memory network

    NASA Astrophysics Data System (ADS)

    Weng, Liguo; Xia, Min; Wang, Wei; Liu, Qingshan

    2015-01-01

    This paper addresses the problem of the crew exploration vehicle (CEV) attitude control. CEVs are NASA's next-generation human spaceflight vehicles, and they use reaction control system (RCS) jet engines for attitude adjustment, which calls for control algorithms for firing the small propulsion engines mounted on vehicles. In this work, the resultant CEV dynamics combines both actuation and attitude dynamics. Therefore, it is highly nonlinear and even coupled with significant uncertainties. To cope with this situation, a neural-immunology/memory network is proposed. It is inspired by the human memory and immune systems. The control network does not rely on precise system dynamics information. Furthermore, the overall control scheme has a simple structure and demands much less computation as compared with most existing methods, making it attractive for real-time implementation. The effectiveness of this approach is also verified via simulation.

  16. Precision Pointing Control to and Accurate Target Estimation of a Non-Cooperative Vehicle

    NASA Technical Reports Server (NTRS)

    VanEepoel, John; Thienel, Julie; Sanner, Robert M.

    2006-01-01

    In 2004, NASA began investigating a robotic servicing mission for the Hubble Space Telescope (HST). Such a mission would not only require estimates of the HST attitude and rates in order to achieve capture by the proposed Hubble Robotic Vehicle (HRV), but also precision control to achieve the desired rate and maintain the orientation to successfully dock with HST. To generalize the situation, HST is the target vehicle and HRV is the chaser. This work presents a nonlinear approach for estimating the body rates of a non-cooperative target vehicle, and coupling this estimation to a control scheme. Non-cooperative in this context relates to the target vehicle no longer having the ability to maintain attitude control or transmit attitude knowledge.

  17. Salinity management in the Rio Grande Bosque

    Treesearch

    Jan M. H. Hendrickx; J. Bruce J. Harrison; Jelle Beekma; Graciela Rodriguez-Marin

    1999-01-01

    This paper discusses management options for salinity control in the Rio Grande Bosque. First, salt sources are identified and quantified. Capillary rise of ground water is the most important cause for soil salinization in the bosque. Next, a riparian salt balance is presented to explain the different mechanisms for soil salinization. Finally, the advantages and...

  18. Numerical Study of Groundwater Flow and Salinity Distribution Cycling Controlled by Seawater/Freshwater Interaction in Karst Aquifer Using SEAWAT

    NASA Astrophysics Data System (ADS)

    Xu, Z.; Hu, B.

    2017-12-01

    The interest to predict seawater intrusion and salinity distribution in Woodville Karst Plain (WKP) has increased due to the huge challenge on quality of drinkable water and serious environmental problems. Seawater intrudes into the conduit system from submarine karst caves at Spring Creek Spring due to density difference and sea level rising, nowadays the low salinity has been detected at Wakulla Spring which is 18 km from coastal line. The groundwater discharge at two major springs and salinity distribution in this area is controlled by the seawater/freshwater interaction under different rainfall conditions: during low rainfall periods, seawater flow into the submarine spring through karst windows, then the salinity rising at the submarine spring leads to seawater further intrudes into conduit system; during high rainfall periods, seawater is pushed out by fresh water discharge at submarine spring. The previous numerical studies of WKP mainly focused on the density independent transport modeling and seawater/freshwater discharge at major karst springs, in this study, a SEAWAT model has been developed to fully investigate the salinity distribution in the WKP under repeating phases of low rainfall and high rainfall periods, the conduit system was simulated as porous media with high conductivity and porosity. The precipitation, salinity and discharge at springs were used to calibrate the model. The results showed that the salinity distribution in porous media and conduit system is controlled by the rainfall change, in general, the salinity distribution inland under low rainfall conditions is much higher and wider than the high rainfall conditions. The results propose a prediction on the environmental problem caused by seawater intrusion in karst coastal aquifer, in addition, provide a visual and scientific basis for future groundwater remediation.

  19. Sensing, Control, and System Integration for Autonomous Vehicles: A Series of Challenges

    NASA Astrophysics Data System (ADS)

    Özgüner, Ümit; Redmill, Keith

    One of the important examples of mechatronic systems can be found in autonomous ground vehicles. Autonomous ground vehicles provide a series of challenges in sensing, control and system integration. In this paper we consider off-road autonomous vehicles, automated highway systems and urban autonomous driving and indicate the unifying aspects. We specifically consider our own experience during the last twelve years in various demonstrations and challenges in attempting to identify unifying themes. Such unifying themes can be observed in basic hierarchies, hybrid system control approaches and sensor fusion techniques.

  20. A reactive torque control law for gyroscopically controlled space vehicles

    NASA Technical Reports Server (NTRS)

    Farmer, J. E.

    1973-01-01

    A method of control is developed based on the reactive torques as seen by the individual CMG gimbals. The application of a torque to the gimbal of a CMG rotates the momentum vector and applies a torque to the spacecraft according to well-known laws. The response (rotation) of the vehicle produces a reverse or reaction torque opposing the torque producing the gimbal movement. The reactive torque and the pseudoinverse control schemes are contrasted in order to point out the simplicity of the first method. Simulation was performed only to the extent necessary to prove that reactive torque stabilization and control is feasible.

  1. Charge control microcomputer device for vehicle

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Morishita, M.; Kouge, S.

    1986-08-26

    A charge control microcomputer device is described for a vehicle, comprising: an AC generator driven by an engine for generating an output current, the generator having armature coils and a field coil; a battery charged by a rectified output of the generator and generating a terminal voltage; a voltage regulator for controlling a current flowing in the field coil, to control an output voltage of the generator to a predetermined value; an engine controlling microcomputer for receiving engine parameter data from the engine, to control the operation of the engine; a charge control microcomputer for processing input data including datamore » on at least one engine parameter output from the engine controlling microcomputer, and charge system data including at least one of battery terminal voltage data, generator voltage data and generator output current data, to provide a reference voltage for the voltage regulator.« less

  2. Stability Assessment and Tuning of an Adaptively Augmented Classical Controller for Launch Vehicle Flight Control

    NASA Technical Reports Server (NTRS)

    VanZwieten, Tannen; Zhu, J. Jim; Adami, Tony; Berry, Kyle; Grammar, Alex; Orr, Jeb S.; Best, Eric A.

    2014-01-01

    Recently, a robust and practical adaptive control scheme for launch vehicles [ [1] has been introduced. It augments a classical controller with a real-time loop-gain adaptation, and it is therefore called Adaptive Augmentation Control (AAC). The loop-gain will be increased from the nominal design when the tracking error between the (filtered) output and the (filtered) command trajectory is large; whereas it will be decreased when excitation of flex or sloshing modes are detected. There is a need to determine the range and rate of the loop-gain adaptation in order to retain (exponential) stability, which is critical in vehicle operation, and to develop some theoretically based heuristic tuning methods for the adaptive law gain parameters. The classical launch vehicle flight controller design technics are based on gain-scheduling, whereby the launch vehicle dynamics model is linearized at selected operating points along the nominal tracking command trajectory, and Linear Time-Invariant (LTI) controller design techniques are employed to ensure asymptotic stability of the tracking error dynamics, typically by meeting some prescribed Gain Margin (GM) and Phase Margin (PM) specifications. The controller gains at the design points are then scheduled, tuned and sometimes interpolated to achieve good performance and stability robustness under external disturbances (e.g. winds) and structural perturbations (e.g. vehicle modeling errors). While the GM does give a bound for loop-gain variation without losing stability, it is for constant dispersions of the loop-gain because the GM is based on frequency-domain analysis, which is applicable only for LTI systems. The real-time adaptive loop-gain variation of the AAC effectively renders the closed-loop system a time-varying system, for which it is well-known that the LTI system stability criterion is neither necessary nor sufficient when applying to a Linear Time-Varying (LTV) system in a frozen-time fashion. Therefore, a

  3. Prefrontal transcranial direct current stimulation improves fundamental vehicle control abilities.

    PubMed

    Sakai, Hiroyuki; Uchiyama, Yuji; Tanaka, Satoshi; Sugawara, Sho K; Sadato, Norihiro

    2014-10-15

    Noninvasive brain stimulation techniques have increasingly attracted the attention of neuroscientists because they enable the identification of the causal role of a targeted brain region. However, few studies have applied such techniques to everyday life situations. Here, we investigate the causal role of the dorsolateral prefrontal cortex (DLPFC) in fundamental vehicle control abilities. Thirteen participants underwent a simulated driving task under prefrontal transcranial direct current stimulation (tDCS) on three separate testing days. Each testing day was randomly assigned to either anodal over the right with cathodal over the left DLPFC, cathodal over the right with anodal over the left DLPFC, or sham stimulation. The driving task required the participants to maintain an inter-vehicle distance to a leading car traveling a winding road with a constant speed. Driving performance was quantified using two metrics: the root-mean-square error of inter-vehicle distance as car-following performance, and the standard deviation of lateral position as lane-keeping performance. Results showed that both car-following and lane-keeping performances were significantly greater for right anodal/left cathodal compared with right cathodal/left cathodal and sham stimulation. These results suggest not only the causal involvement of the DLPFC in driving, but also right hemisphere dominance for vehicle control. The findings of this study indicate that tDCS can be a useful tool to examine the causal role of a specific brain region in ecologically valid environments, and also might be a help to drivers with difficulties in vehicle control. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Local infiltration of the surgical wounds with levobupivacaine, dexibuprofen, and norepinephrine to reduce postoperative pain: A randomized, vehicle-controlled, and preclinical study.

    PubMed

    Gao, Zongwen; Cui, Feng; Cao, Xuemei; Wang, Dejun; Li, Xiao; Li, Tianzuo

    2017-08-01

    Postoperative pain may lead to poor wound healing, insomnia, and increased postoperative hospitalization. The objective of the study was to explore the effect of local infiltration of the surgical wound with levobupivacaine, dexibuprofen, and norepinephrine in postoperative pain. A randomized, parallel experimental design was applied in 40, 9-11-week-old Wister albino rats. A laparotomy was performed in all groups of 10 rats each. During surgery, the sutured muscle was infiltrated with 40μL of a normal saline (vehicle group), a normal saline containing 0.25% v/v levobupivacaine, 0.2mg/mL dexibuprofen, and 0.1mg/mL norepinephrine (treatment group) before skin closure. The same combination (negative control group) and a 10-fold higher dose (positive control group) were administered systematically. Rat Grimace Scale scores, based on facial expression, 24h after suturing of the tissues, histopathology and tensile strength of the surgical wound, two weeks after suturing of the tissues were measured. The one-way ANOVA and the two-tailed paired t-test/the Dunnett multiple comparisons test were used to compare the Rat Grimace Scale scores for pain within the group and between groups. The Kruskal-Wallis test and the one-way ANOVA/the Dunnett multiple comparisons test were used to compare the histopathology study and the tensile strength. The difference for statistical analysis was considered significant at the 95% of confidence level. The mean Rat Grimace Scale score at 24h for the treatment, negative control, and positive control groups was 1.945 (p=0.0025; q=3.257), 1.1 (p=0.1), and 1.95 (p=0.0021 q=3.547) respectively. The reduction in postoperative pain started within 1h after the suturing of the tissues in the treatment group. There were significant difference for epidermal and dermal regeneration (p=0.043), granulation tissue thickness (p=0.025), and angiogenesis (p=0.002) between treatment group and vehicle group. Tensile strength for the treatment group was 0.82±0

  5. X-37 Space Vehicle: Starting a New Age in Space Control?

    NASA Astrophysics Data System (ADS)

    Jameson, Austin D.

    2001-04-01

    The U.S. can no longer rely on the "space as a sanctuary" policy, initiated by the Eisenhower Administration, to continue to exploit space for economic and military advantages. The X-37 space maneuvering vehicle demonstrator is an opportunity for the U.S. to begin to develop methods to more strategically defend and control the space environment. The X-37 is the first of NASA's x-vehicles intended to demonstrate leading edge technologies in orbit. This prototype space maneuvering vehicle co-sponsored by NASA, the Air Force and the Boeing Company is being designed to achieve the goals of reducing the cost to access space from 10,000 to 1000 per pound while improving reliability. The current project is funded to build an autonomous space maneuvering vehicle with on-orbit testing scheduled in 2002, The X-37 is an unmanned space plane that can carry a payload, and can conduct missions while orbiting, loitering, or rendezvousing with objects in space and then autonomously return to earth by landing on a conventional runway. If the Air Force develops the X-37 to its full potential the system could strategically support each of the Air Force's four space mission areas of force enhancement, space support, space control, and force application. Transition of the space maneuvering demonstrator into a space control platform will require a change in national policy. Capitalizing on the lessons from NASA's x-vehicles and partnering with the commercial sector can potentially save costs and shorten the development of a viable space platform that could be used for space control. Strategic development and funded evolution of the X-37 space vehicle is an immediate, tangible step the United States can take to actively pursue a more aggressive program to respond to threats in the space arena.

  6. Control of Sulfide Production in High Salinity Bakken Shale Oil Reservoirs by Halophilic Bacteria Reducing Nitrate to Nitrite

    PubMed Central

    An, Biwen A.; Shen, Yin; Voordouw, Gerrit

    2017-01-01

    Microbial communities in shale oil fields are still poorly known. We obtained samples of injection, produced and facility waters from a Bakken shale oil field in Saskatchewan, Canada with a resident temperature of 60°C. The injection water had a lower salinity (0.7 Meq of NaCl) than produced or facility waters (0.6–3.6 Meq of NaCl). Salinities of the latter decreased with time, likely due to injection of low salinity water, which had 15–30 mM sulfate. Batch cultures of field samples showed sulfate-reducing and nitrate-reducing bacteria activities at different salinities (0, 0.5, 0.75, 1.0, 1.5, and 2.5 M NaCl). Notably, at high salinity nitrite accumulated, which was not observed at low salinity, indicating potential for nitrate-mediated souring control at high salinity. Continuous culture chemostats were established in media with volatile fatty acids (a mixture of acetate, propionate and butyrate) or lactate as electron donor and nitrate or sulfate as electron acceptor at 0.5 to 2.5 M NaCl. Microbial community analyses of these cultures indicated high proportions of Halanaerobium, Desulfovermiculus, Halomonas, and Marinobacter in cultures at 2.5 M NaCl, whereas Desulfovibrio, Geoalkalibacter, and Dethiosulfatibacter were dominant at 0.5 M NaCl. Use of bioreactors to study the effect of nitrate injection on sulfate reduction showed that accumulation of nitrite inhibited SRB activity at 2.5 M but not at 0.5 M NaCl. High proportions of Halanaerobium and Desulfovermiculus were found at 2.5 M NaCl in the absence of nitrate, whereas high proportions of Halomonas and no SRB were found in the presence of nitrate. A diverse microbial community dominated by the SRB Desulfovibrio was observed at 0.5 M NaCl both in the presence and absence of nitrate. Our results suggest that nitrate injection can prevent souring provided that the salinity is maintained at a high level. Thus, reinjection of high salinity produced water amended with nitrate maybe be a cost effective

  7. Flight control augmentation for AFT CG launch vehicles

    NASA Technical Reports Server (NTRS)

    Barret, Chris

    1996-01-01

    The Space Shuttle was only the first step in achieving routine access to space. Recently, the NASA Marshall Space Flight Center (MSFC) has been studying a whole spectrum of new launch vehicles (L/V's) for space transportation. Some of these could transport components of the Space Station to orbit, and some could take us to Mars and beyond to boldly expand our frontiers of knowledge. In all our future launch vehicle (L/V) designs, decreasing the structural weight will always be of great concern. This is tantamount to increased payload capability, which in turn means reduced cost-per-pound to orbit. One very significant increase in payload capability has been defined. In a L/V recently studied at MSFC it has been shown that a sizable weight savings can be realized by a rearrangement of the internal propellant tanks. Studies have been conducted both at MSFC and at Martin Marietta Corporation, maker of the Space Shuttle External Tank (ET) which show that a very substantial weight can be saved by inverting the relative positions of the liquid hydrogen (LH2) and the liquid oxygen (LOX) propellant tanks in a particular L/V studied. As the vehicle sits on the launch pad, in the conventional configuration the heavier LOX tank is located on top of the lighter LH2. This requires a heavy structural member between the two tanks to prevent the lighter LH2 tank from being crushed. This configuration also requires large, long, and even drag producing LOX feed lines running the length of the vehicle on the exterior fuselage. If the relative position of the propellant tanks is inverted, both the heavy structural separation member and the long LOX feed lines could be deleted. While the structures community at MSFC was elated with this finding, the LOX tank aft configuration gave the vehicle an aft center-of-gravity (cg) location which surfaced controllability concerns. In the conventional configuration the L/V is controlled in the ascent trajectory by the gimballing of its rocket

  8. Advanced Suspension and Control Algorithm for U.S. Army Ground Vehicles

    DTIC Science & Technology

    2013-04-01

    Army Materiel Systems Analysis Activity (AMSAA), for his assistance and guidance in building a multibody vehicle dynamics model of a typical light...Mobility Multipurpose Wheeled Vehicle [HMMWV] model) that was developed in collaboration with the U.S. Army Materiel Systems Analysis Activity (5) is...control weight for GPC With Explicit Disturbance was R = 1.0e-7 over the entire speed range. To simplify analysis , the control weights for the other two

  9. Tire-road friction estimation and traction control strategy for motorized electric vehicle

    PubMed Central

    Jin, Li-Qiang; Yue, Weiqiang

    2017-01-01

    In this paper, an optimal longitudinal slip ratio system for real-time identification of electric vehicle (EV) with motored wheels is proposed based on the adhesion between tire and road surface. First and foremost, the optimal longitudinal slip rate torque control can be identified in real time by calculating the derivative and slip rate of the adhesion coefficient. Secondly, the vehicle speed estimation method is also brought. Thirdly, an ideal vehicle simulation model is proposed to verify the algorithm with simulation, and we find that the slip ratio corresponds to the detection of the adhesion limit in real time. Finally, the proposed strategy is applied to traction control system (TCS). The results showed that the method can effectively identify the state of wheel and calculate the optimal slip ratio without wheel speed sensor; in the meantime, it can improve the accelerated stability of electric vehicle with traction control system (TCS). PMID:28662053

  10. Vehicle-to-infrastructure program cooperative adaptive cruise control.

    DOT National Transportation Integrated Search

    2015-03-01

    This report documents the work completed by the Crash Avoidance Metrics Partners LLC (CAMP) Vehicle to Infrastructure (V2I) Consortium during the project titled Cooperative Adaptive Cruise Control (CACC). Participating companies in the V2I Cons...

  11. Improved SCR ac Motor Controller for Battery Powered Urban Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Latos, T. S.

    1982-01-01

    An improved ac motor controller, which when coupled to a standard ac induction motor and a dc propulsion battery would provide a complete electric vehicle power train with the exception of the mechanical transmission and drive wheels was designed. In such a system, the motor controller converts the dc electrical power available at the battery terminals to ac electrical power for the induction motor in response to the drivers commands. The performance requirements of a hypothetical electric vehicle with an upper weight bound of 1590 kg (3500 lb) were used to determine the power rating of the controller. Vehicle acceleration capability, top speed, and gradeability requisites were contained in the Society of Automotive Engineers (SAE) Schedule 227a(d) driving cycle. The important capabilities contained in this driving cycle are a vehicle acceleration requirement of 0 to 72.4 kmph (0 to 45 mph) in 28 seconds a top speed of 88.5 kmph (55 mph), and the ability to negotiate a 10% grade at 48 kmph (30 mph). A 10% grade is defined as one foot of vertical rise per 10 feet of horizontal distance.

  12. Ground control station software design for micro aerial vehicles

    NASA Astrophysics Data System (ADS)

    Walendziuk, Wojciech; Oldziej, Daniel; Binczyk, Dawid Przemyslaw; Slowik, Maciej

    2017-08-01

    This article describes the process of designing the equipment part and the software of a ground control station used for configuring and operating micro unmanned aerial vehicles (UAV). All the works were conducted on a quadrocopter model being a commonly accessible commercial construction. This article contains a characteristics of the research object, the basics of operating the micro aerial vehicles (MAV) and presents components of the ground control station model. It also describes the communication standards for the purpose of building a model of the station. Further part of the work concerns the software of the product - the GIMSO application (Generally Interactive Station for Mobile Objects), which enables the user to manage the actions and communication and control processes from the UAV. The process of creating the software and the field tests of a station model are also presented in the article.

  13. Research on Acceleration Compensation Strategy of Electric Vehicle Based on Fuzzy Control Theory

    NASA Astrophysics Data System (ADS)

    Zhu, Tianjun; Li, Bin; Zong, Changfu; Wei, Zhicheng

    2017-09-01

    Nowadays, the driving technology of electric vehicle is developing rapidly. There are many kinds of methods in driving performance control technology. The paper studies the acceleration performance of electric vehicle. Under the premise of energy management, an acceleration power compensation method by fuzzy control theory based on driver intention recognition is proposed, which can meet the driver’s subjective feelings better. It avoids the problem that the pedal opening and power output are single correspondence when the traditional vehicle accelerates. Through the simulation test, this method can significantly improve the performance of acceleration and output torque smoothly in non-emergency acceleration to ensure vehicle comfortable and stable.

  14. Decoupling control of steering and driving system for in-wheel-motor-drive electric vehicle

    NASA Astrophysics Data System (ADS)

    Zhang, Han; Zhao, Wanzhong

    2018-02-01

    To improve the maneuverability and stability of in-wheel-motor-drive electric vehicle, a control strategy based on nonlinear decoupling control method is proposed in this paper, realizing the coordinated control of the steering and driving system. At first, the nonlinear models of the in-wheel-motor-drive electric vehicle and its sub-system are constructed. Then the inverse system decoupling theory is applied to decompose the nonlinear system into several independent subsystems, which makes it possible to realize the coordinated control of each subsystem. Next, the μ-Synthesis theory is applied to eliminate the influence of model uncertainty, improving the stability, robustness and tracking performance of in-wheel-motor-drive electric vehicle. Simulation and experiment results and numerical analyses, based on the electric vehicle actuated by in-wheel-motors, prove that the proposed control method is effective to accomplish the decoupling control of the steering and driving system in both simulation and real practice.

  15. Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

    NASA Technical Reports Server (NTRS)

    Peak, S. C.

    1982-01-01

    An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

  16. Orientation Guidance and Control for Marine Vehicles in the Horizontal Plane

    DTIC Science & Technology

    1991-06-01

    FIELD GROUP SUB-GROUP Autonomous vehicles , Guidance and control, Stability, Path keeping 19 ABSIRACT (Continue on reverse if necessary and identify by...following in 3-D space. 33 LIST OF REFERENCES 1. Kanayama, Y. and Hartman, B.I. (1989) " Smooth local path planning for autonomous vehicles , " Proceeding

  17. Advanced control concepts. [for shuttle ascent vehicles

    NASA Technical Reports Server (NTRS)

    Sharp, J. B.; Coppey, J. M.

    1973-01-01

    The problems of excess control devices and insufficient trim control capability on shuttle ascent vehicles were investigated. The trim problem is solved at all time points of interest using Lagrangian multipliers and a Simplex based iterative algorithm developed as a result of the study. This algorithm has the capability to solve any bounded linear problem with physically realizable constraints, and to minimize any piecewise differentiable cost function. Both solution methods also automatically distribute the command torques to the control devices. It is shown that trim requirements are unrealizable if only the orbiter engines and the aerodynamic surfaces are used.

  18. Rear wheel torque vectoring model predictive control with velocity regulation for electric vehicles

    NASA Astrophysics Data System (ADS)

    Siampis, Efstathios; Velenis, Efstathios; Longo, Stefano

    2015-11-01

    In this paper we propose a constrained optimal control architecture for combined velocity, yaw and sideslip regulation for stabilisation of the vehicle near the limit of lateral acceleration using the rear axle electric torque vectoring configuration of an electric vehicle. A nonlinear vehicle and tyre model are used to find reference steady-state cornering conditions and design two model predictive control (MPC) strategies of different levels of fidelity: one that uses a linearised version of the full vehicle model with the rear wheels' torques as the input, and another one that neglects the wheel dynamics and uses the rear wheels' slips as the input instead. After analysing the relative trade-offs between performance and computational effort, we compare the two MPC strategies against each other and against an unconstrained optimal control strategy in Simulink and Carsim environment.

  19. Flight Control of Biomimetic Air Vehicles Using Vibrational Control and Averaging

    NASA Astrophysics Data System (ADS)

    Tahmasian, Sevak; Woolsey, Craig A.

    2017-08-01

    A combination of vibrational inputs and state feedback is applied to control the flight of a biomimetic air vehicle. First, a control strategy is developed for longitudinal flight, using a quasi-steady aerodynamic model and neglecting wing inertial effects. Vertical and forward motion is controlled by modulating the wings' stroke and feather angles, respectively. Stabilizing control parameter values are determined using the time-averaged dynamic model. Simulations of a system resembling a hawkmoth show that the proposed controller can overcome modeling error associated with the wing inertia and small parameter uncertainties when following a prescribed trajectory. After introducing the approach through an application to longitudinal flight, the control strategy is extended to address flight in three-dimensional space.

  20. Control of pulmonary absorption of water-soluble compounds by various viscous vehicles.

    PubMed

    Yamamoto, Akira; Yamada, Keigo; Muramatsu, Hideaki; Nishinaka, Asako; Okumura, Shigeki; Okada, Naoki; Fujita, Takuya; Muranishi, Shozo

    2004-09-10

    Effects of various viscous vehicles on the pulmonary absorption of water-soluble drugs were examined by an in situ pulmonary absorption experiment. Gelatin, polyvinylacohol (PVA), hydroxypropylcellose (HPC), chondroitin sulfate A sodium salt (CS), polyacrylic acid (PAA), methylcellulose #400 (MC400) and hyaluronic acid sodium salt (HA) were used as models of viscous vehicles. 5(6)-Carboxyfluorescein (CF) and fluorescein isothiocayanate-labeled dextran with an average molecular weight of 4000 (FD4) were used as water-soluble drugs. The plasma concentration of CF was controlled and regulated in the presence of these viscous vehicles, especially gelatin (1-5%) and polyvinyl alcohol (PVA) 1%. In the pharmacokinetic analysis, the Cmax values of CF significantly decreased, and its Tmax values increased in the presence of these viscous vehicles compared with the control. The MRT and MAT values of CF with these vehicles were significantly higher than those without these vehicles. Therefore, these findings indicated that the viscous vehicles were effective to regulate the absorption rate of CF. On the other hand, the pulmonary absorption of FD4 was not so much affected even in the presence of gelatin and PVA, although PVA slightly decreased MRT value, and significantly decreased Tmax value. Furthermore, we examined the release rate of CF from the cellulose tube containing various concentrations of gelatin. The release rate of CF from the cellulose tube with gelatin was inversely related to the viscosity of gelatin. In addition, the release rate of CF was inversely related to DeltaMAT (DeltaMAT = MATgel(MAT with gelatin)-MATsol(MAT without gelatin)) in the presence of varying concentrations of gelatin. These findings indicated that these viscous vehicles were effective to control the pulmonary absorption of CF, a water-soluble drug with low molecular weight and they might be useful to increase the local concentration of drugs in the lung.

  1. Improving traffic flow at a 2-to-1 lane reduction with wirelessly connected, adaptive cruise control vehicles

    NASA Astrophysics Data System (ADS)

    Davis, L. C.

    2016-06-01

    Wirelessly connected vehicles that exchange information about traffic conditions can reduce delays caused by congestion. At a 2-to-1 lane reduction, the improvement in flow past a bottleneck due to traffic with a random mixture of 40% connected vehicles is found to be 52%. Control is based on connected-vehicle-reported velocities near the bottleneck. In response to indications of congestion the connected vehicles, which are also adaptive cruise control vehicles, reduce their speed in slowdown regions. Early lane changes of manually driven vehicles from the terminated lane to the continuous lane are induced by the slowing connected vehicles. Self-organized congestion at the bottleneck is thus delayed or eliminated, depending upon the incoming flow magnitude. For the large majority of vehicles, travel times past the bottleneck are substantially reduced. Control is responsible for delaying the onset of congestion as the incoming flow increases. Adaptive cruise control increases the flow out of the congested state at the bottleneck. The nature of the congested state, when it occurs, appears to be similar under a variety of conditions. Typically 80-100 vehicles are approximately equally distributed between the lanes in the 500 m region prior to the end of the terminated lane. Without the adaptive cruise control capability, connected vehicles can delay the onset of congestion but do not increase the asymptotic flow past the bottleneck. Calculations are done using the Kerner-Klenov three-phase theory, stochastic discrete-time model for manual vehicles. The dynamics of the connected vehicles is given by a conventional adaptive cruise control algorithm plus commanded deceleration. Because time in the model for manual vehicles is discrete (one-second intervals), it is assumed that the acceleration of any vehicle immediately in front of a connected vehicle is constant during the time interval, thereby preserving the computational simplicity and speed of a discrete-time model.

  2. Electric machine differential for vehicle traction control and stability control

    NASA Astrophysics Data System (ADS)

    Kuruppu, Sandun Shivantha

    Evolving requirements in energy efficiency and tightening regulations for reliable electric drivetrains drive the advancement of the hybrid electric (HEV) and full electric vehicle (EV) technology. Different configurations of EV and HEV architectures are evaluated for their performance. The future technology is trending towards utilizing distinctive properties in electric machines to not only to improve efficiency but also to realize advanced road adhesion controls and vehicle stability controls. Electric machine differential (EMD) is such a concept under current investigation for applications in the near future. Reliability of a power train is critical. Therefore, sophisticated fault detection schemes are essential in guaranteeing reliable operation of a complex system such as an EMD. The research presented here emphasize on implementation of a 4kW electric machine differential, a novel single open phase fault diagnostic scheme, an implementation of a real time slip optimization algorithm and an electric machine differential based yaw stability improvement study. The proposed d-q current signature based SPO fault diagnostic algorithm detects the fault within one electrical cycle. The EMD based extremum seeking slip optimization algorithm reduces stopping distance by 30% compared to hydraulic braking based ABS.

  3. [Investigation and canonical correspondence analysis of salinity contents in secondary salinization greenhouse soils in Shanghai suburb].

    PubMed

    Tang, Dong; Mao, Liang; Zhi, Yue-e; Zhang, Jin-Zhong; Zhou, Pei; Chai, Xiao-Tong

    2014-12-01

    The salinity characteristics of greenhouse soils with cropping obstacles in Shanghai suburb were investigated and analyzed. The salinity contents of the salinization greenhouse soils showed a trend of first increasing and then decreasing with the increasing cropping duration. The salinized soils mainly included slightly salted, mildly salted and salted soils, which accounted for 17.39%, 56.52% and 13.04%, respectively. Among them, the degree of salinity in greenhouse soil planted with asparagus in Chongming County was the highest. Among the salt ions in greenhouse soils, the cations were mainly Ca2+ and Na+, while the anions were mainly NO3- and SO4(2-). The degree of salinity was mainly influenced by fertilization mode, cropping duration, crop type and management level, which led to the great variation in the salinity contents and salt ions. Canonical correspondence analysis found that the contents of Ca2+, Mg2+ and NO3- in greenhouse soils were greatly affected by cropping duration, and the degree of salinity would be enhanced and attenuated with long-term application of single fertilizer and mixed application of chemical fertilizer and organic manure, respectively. The greenhouse soils in Shanghai suburb could be classified as four patterns influenced by the relationship between salinity ions and samples, and the most soils were influenced by Ca2+, Mg2+, NO3- and Cl-, which required to be primarily controlled.

  4. Distributed formation control of nonholonomic autonomous vehicle via RBF neural network

    NASA Astrophysics Data System (ADS)

    Yang, Shichun; Cao, Yaoguang; Peng, Zhaoxia; Wen, Guoguang; Guo, Konghui

    2017-03-01

    In this paper, RBF neural network consensus-based distributed control scheme is proposed for nonholonomic autonomous vehicles in a pre-defined formation along the specified reference trajectory. A variable transformation is first designed to convert the formation control problem into a state consensus problem. Then, the complete dynamics of the vehicles including inertia, Coriolis, friction model and unmodeled bounded disturbances are considered, which lead to the formation unstable when the distributed kinematic controllers are proposed based on the kinematics. RBF neural network torque controllers are derived to compensate for them. Some sufficient conditions are derived to accomplish the asymptotically stability of the systems based on algebraic graph theory, matrix theory, and Lyapunov theory. Finally, simulation examples illustrate the effectiveness of the proposed controllers.

  5. Improving travel times for emergency response vehicles : traffic control strategies based on connected vehicles technologies.

    DOT National Transportation Integrated Search

    2014-09-01

    This research is focused on developing and evaluating new traffic control strategies to enable emergency response vehicles : (EVs) to travel in transportation networks as quickly as possible while the disruption to the rest of the traffic is kept to ...

  6. Adaptive integral dynamic surface control of a hypersonic flight vehicle

    NASA Astrophysics Data System (ADS)

    Aslam Butt, Waseem; Yan, Lin; Amezquita S., Kendrick

    2015-07-01

    In this article, non-linear adaptive dynamic surface air speed and flight path angle control designs are presented for the longitudinal dynamics of a flexible hypersonic flight vehicle. The tracking performance of the control design is enhanced by introducing a novel integral term that caters to avoiding a large initial control signal. To ensure feasibility, the design scheme incorporates magnitude and rate constraints on the actuator commands. The uncertain non-linear functions are approximated by an efficient use of the neural networks to reduce the computational load. A detailed stability analysis shows that all closed-loop signals are uniformly ultimately bounded and the ? tracking performance is guaranteed. The robustness of the design scheme is verified through numerical simulations of the flexible flight vehicle model.

  7. Active Vibration Control of a Railway Vehicle Carbody Using Piezoelectric Elements

    NASA Astrophysics Data System (ADS)

    Molatefi, Habibollah; Ayoubi, Pejman; Mozafari, Hozhabr

    2017-07-01

    In recent years and according to modern transportation development, rail vehicles are manufactured lighter to achieve higher speed and lower transportation costs. On the other hand, weight reduction of rail vehicles leads to increase the structural vibration. In this study, Active Vibration Control of a rail vehicle using piezoelectric elements is investigated. The optimal control employed as the control approach regard to the first two modes of vibration. A simplified Car body structure is modeled in Matlab using the finite element theory by considering six DOF beam element and then the Eigen functions and mode shapes are derived. The surface roughness of different classes of rail tracks have been obtained using random vibration theory and applied to the secondary suspension as the excitation of the structure; Then piezoelectric mounted where the greatest moments were captured. The effectiveness of Piezoelectric in structural vibrations attenuation of car body is demonstrated through the state space equations and its effect on modal coefficient.

  8. Attitude Control for an Aero-Vehicle Using Vector Thrusting and Variable Speed Control Moment Gyros

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Lim, K. B.; Moerder, D. D.

    2005-01-01

    Stabilization of passively unstable thrust-levitated vehicles can require significant control inputs. Although thrust vectoring is a straightforward choice for realizing these inputs, this may lead to difficulties discussed in the paper. This paper examines supplementing thrust vectoring with Variable-Speed Control Moment Gyroscopes (VSCMGs). The paper describes how to allocate VSCMGs and the vectored thrust mechanism for attitude stabilization in frequency domain and also shows trade-off between vectored thrust and VSCMGs. Using an H2 control synthesis methodology in LMI optimization, a feedback control law is designed for a thrust-levitated research vehicle and is simulated with the full nonlinear model. It is demonstrated that VSCMGs can reduce the use of vectored thrust variation for stabilizing the hovering platform in the presence of strong wind gusts.

  9. Climate Control Load Reduction Strategies for Electric Drive Vehicles in Cold Weather

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jeffers, Matthew A.; Chaney, Larry; Rugh, John P.

    When operated, the climate control system is the largest auxiliary load on a vehicle. This load has significant impact on fuel economy for conventional and hybrid vehicles, and it drastically reduces the driving range of all electric vehicles (EVs). Heating is even more detrimental to EV range than cooling because no engine waste heat is available. Reducing the thermal loads on the heating, ventilating, and air conditioning system will extend driving range and increase the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have evaluated strategies for vehicle climate control load reduction with special attention toward gridmore » connected electric vehicles. Outdoor vehicle thermal testing and computational modeling were used to assess potential strategies for improved thermal management and to evaluate the effectiveness of thermal load reduction technologies. A human physiology model was also used to evaluate the impact on occupant thermal comfort. Experimental evaluations of zonal heating strategies demonstrated a 5.5% to 28.5% reduction in cabin heating energy over a 20-minute warm-up. Vehicle simulations over various drive cycles show a 6.9% to 18.7% improvement in EV range over baseline heating using the most promising zonal heating strategy investigated. A national-level analysis was conducted to determine the overall national impact. If all vehicles used the best zonal strategy, the range would be improved by 7.1% over the baseline heating range. This is a 33% reduction in the range penalty for heating.« less

  10. Design of safety-oriented control allocation strategies for overactuated electric vehicles

    NASA Astrophysics Data System (ADS)

    de Castro, Ricardo; Tanelli, Mara; Esteves Araújo, Rui; Savaresi, Sergio M.

    2014-08-01

    The new vehicle platforms for electric vehicles (EVs) that are becoming available are characterised by actuator redundancy, which makes it possible to jointly optimise different aspects of the vehicle motion. To do this, high-level control objectives are first specified and solved with appropriate control strategies. Then, the resulting virtual control action must be translated into actual actuator commands by a control allocation layer that takes care of computing the forces to be applied at the wheels. This step, in general, is quite demanding as far as computational complexity is considered. In this work, a safety-oriented approach to this problem is proposed. Specifically, a four-wheel steer EV with four in-wheel motors is considered, and the high-level motion controller is designed within a sliding mode framework with conditional integrators. For distributing the forces among the tyres, two control allocation approaches are investigated. The first, based on the extension of the cascading generalised inverse method, is computationally efficient but shows some limitations in dealing with unfeasible force values. To solve the problem, a second allocation algorithm is proposed, which relies on the linearisation of the tyre-road friction constraints. Extensive tests, carried out in the CarSim simulation environment, demonstrate the effectiveness of the proposed approach.

  11. Distributed pheromone-based swarming control of unmanned air and ground vehicles for RSTA

    NASA Astrophysics Data System (ADS)

    Sauter, John A.; Mathews, Robert S.; Yinger, Andrew; Robinson, Joshua S.; Moody, John; Riddle, Stephanie

    2008-04-01

    The use of unmanned vehicles in Reconnaissance, Surveillance, and Target Acquisition (RSTA) applications has received considerable attention recently. Cooperating land and air vehicles can support multiple sensor modalities providing pervasive and ubiquitous broad area sensor coverage. However coordination of multiple air and land vehicles serving different mission objectives in a dynamic and complex environment is a challenging problem. Swarm intelligence algorithms, inspired by the mechanisms used in natural systems to coordinate the activities of many entities provide a promising alternative to traditional command and control approaches. This paper describes recent advances in a fully distributed digital pheromone algorithm that has demonstrated its effectiveness in managing the complexity of swarming unmanned systems. The results of a recent demonstration at NASA's Wallops Island of multiple Aerosonde Unmanned Air Vehicles (UAVs) and Pioneer Unmanned Ground Vehicles (UGVs) cooperating in a coordinated RSTA application are discussed. The vehicles were autonomously controlled by the onboard digital pheromone responding to the needs of the automatic target recognition algorithms. UAVs and UGVs controlled by the same pheromone algorithm self-organized to perform total area surveillance, automatic target detection, sensor cueing, and automatic target recognition with no central processing or control and minimal operator input. Complete autonomy adds several safety and fault tolerance requirements which were integrated into the basic pheromone framework. The adaptive algorithms demonstrated the ability to handle some unplanned hardware failures during the demonstration without any human intervention. The paper describes lessons learned and the next steps for this promising technology.

  12. Autocommander: A Supervisory Controller for Integrated Guidance and Control for the 2nd Generation Reusable Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Fisher, J. E.; Lawrence, D. A.; Zhu, J. J.; Jackson, Scott (Technical Monitor)

    2002-01-01

    This paper presents a hierarchical architecture for integrated guidance and control that achieves risk and cost reduction for NASA's 2d generation reusable launch vehicle (RLV). Guidance, attitude control, and control allocation subsystems that heretofore operated independently will now work cooperatively under the coordination of a top-level autocommander. In addition to delivering improved performance from a flight mechanics perspective, the autocommander is intended to provide an autonomous supervisory control capability for traditional mission management under nominal conditions, G&C reconfiguration in response to effector saturation, and abort mode decision-making upon vehicle malfunction. This high-level functionality is to be implemented through the development of a relational database that is populated with the broad range of vehicle and mission specific data and translated into a discrete event system model for analysis, simulation, and onboard implementation. A Stateflow Autocoder software tool that translates the database into the Stateflow component of a Matlab/Simulink simulation is also presented.

  13. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

    NASA Technical Reports Server (NTRS)

    Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. V.; Yerazunis, S. W.

    1973-01-01

    Problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars are reported. Problem areas include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis, terrain modeling and path selection; and chemical analysis of specimens. These tasks are summarized: vehicle model design, mathematical model of vehicle dynamics, experimental vehicle dynamics, obstacle negotiation, electrochemical controls, remote control, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, and chromatograph model evaluation and improvement.

  14. 2. LAUNCH CONTROL SUPPORT BUILDING WEST FRONT AND VEHICLE STORAGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. LAUNCH CONTROL SUPPORT BUILDING WEST FRONT AND VEHICLE STORAGE BUILDING SOUTHWEST FRONT. VIEW TO EAST. - Minuteman III ICBM Launch Control Facility November-1, 1.5 miles North of New Raymer & State Highway 14, New Raymer, Weld County, CO

  15. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    DOEpatents

    Murty, Balarama Vempaty

    2000-01-01

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  16. California motor vehicle pollution control: emission control system warranty regulations waiver of federal preemption

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    1979-10-23

    The U.S. Environmental Protection Agency has decided that the California Air Resources Board's (CARB) regulations on emission control system warranties for motor vehicles and engines sold in the state fall within the scope of previous waivers of federal preemption under the Clean Air Act; that they are neither standards nor enforcement procedures; and that they need not receive a separate waiver of federal preemption for their enforcement. Adopted on 12/14/78, the CARB regulations apply to all California certified 1973 and subsequent model year motorcycles, light-, medium-, and heavy-duty motor vehicles and engines. The decision, which followed a 5/17/79 public hearingmore » in San Francisco, Calif., will affect not only California motor vehicle manufacturers and industries but also those outside the state which sell the subject vehicles in California, thus, making it one of nationwide scope and effect.« less

  17. Advanced Control Surface Seal Development for Future Space Vehicles

    NASA Technical Reports Server (NTRS)

    DeMange, Jeffrey J.; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.

    2004-01-01

    High temperature control surface seals have been identified as a critical technology in the development of future space vehicles. These seals must withstand temperatures of up to 2600 F and protect underlying temperature-sensitive structures (such as actuators and sealing capability by remaining resilient during flight conditions. The current baseline seal, used on the Shuttle orbiters and the X-38 vehicle, consists of a Nextel 312 sheath, an internal Inconel X-750 knitted spring tube, and hand-stuffed Saffil batting. Unfortunately at high temperatures (> 1500 F), the seal resiliency significantly degrades due to yielding and creep of the spring tube element. The permanent set in the seals can result in flow passing over the seals and subsequent damage to temperature sensitive components downstream of the seals. Another shortcoming of the baseline seal is that instances have been reported on Shuttle flights where some of the hand-stuffed Saffil batting insulation has been extracted, thus potentially compromising the seal. In vehicles where the thermal protection systems are delicate (such as with Shuttle tiles), the control surface seals must also limit the amount of force applied to the opposing surfaces. Additionally, in many applications the seals are subjected to scrubbing as control surfaces are actuated. The seals must be able to withstand any damage resulting from this high temperature scrubbing and retain their heat/flow blocking abilities.

  18. A New Approach to Attitude Stability and Control for Low Airspeed Vehicles

    NASA Technical Reports Server (NTRS)

    Lim, K. B.; Shin, Y-Y.; Moerder, D. D.; Cooper, E. G.

    2004-01-01

    This paper describes an approach for controlling the attitude of statically unstable thrust-levitated vehicles in hover or slow translation. The large thrust vector that characterizes such vehicles can be modulated to provide control forces and moments to the airframe, but such modulation is accompanied by significant unsteady flow effects. These effects are difficult to model, and can compromise the practical value of thrust vectoring in closed-loop attitude stability, even if the thrust vectoring machinery has sufficient bandwidth for stabilization. The stabilization approach described in this paper is based on using internal angular momentum transfer devices for stability, augmented by thrust vectoring for trim and other "outer loop" control functions. The three main components of this approach are: (1) a z-body axis angular momentum bias enhances static attitude stability, reducing the amount of control activity needed for stabilization, (2) optionally, gimbaled reaction wheels provide high-bandwidth control torques for additional stabilization, or agility, and (3) the resulting strongly coupled system dynamics are controlled by a multivariable controller. A flight test vehicle is described, and nonlinear simulation results are provided that demonstrate the efficiency of the approach.

  19. Historical evaluation of vehicle emission control in Guangzhou based on a multi-year emission inventory

    NASA Astrophysics Data System (ADS)

    Zhang, Shaojun; Wu, Ye; Liu, Huan; Wu, Xiaomeng; Zhou, Yu; Yao, Zhiliang; Fu, Lixin; He, Kebin; Hao, Jiming

    2013-09-01

    The Guangzhou government adopted many vehicle emission control policies and strategies during the five-year preparation (2005-2009) to host the 2010 Asian Games. This study established a multi-year emission inventory for vehicles in Guangzhou during 2005-2009 and estimated the uncertainty in total vehicle emissions by taking the assumed uncertainties in fleet-average emission factors and annual mileage into account. In 2009, the estimated total vehicle emissions in Guangzhou were 313 000 (242 000-387 000) tons of CO, 60 900 (54 000-70 200) tons of THC, 65 600 (56 800-74 100) tons of NOx and 2740 (2100-3400) tons of PM10. Vehicle emissions within the urban area of Guangzhou were estimated to be responsible for ˜40% of total gaseous pollutants and ˜25% of total PM10 in the entire city. Although vehicle use intensity increased rapidly in Guangzhou during 2005-2009, vehicle emissions were estimated to have been reduced by 12% for CO, 21% for THC and 20% for PM10 relative to those in 2005. NOx emissions were estimated to have remained almost constant during this period. Compared to the "without control" scenario, 19% (15%-23%) of CO, 20% (18%-23%) of THC, 9% (8%-10%) of NOx and 16% (12%-20%) of PM10 were estimated to have been mitigated from a combination of the implementation of Euro III standards for light-duty vehicles (LDVs) and heavy-duty diesel vehicles and improvement of fuel quality. This study also evaluated several enhanced vehicle emission control actions taken recently. For example, the enhanced I/M program for LDVs was estimated to reduce 11% (9%-14%) of CO, 9% (8%-10%) of THC and 2% (2%-3%) of NOx relative to total vehicle emissions in 2009. Total emission reductions by temporary traffic controls for the Asian Games were estimated equivalent to 9% (7%-11%) of CO, 9% (8%-10%) of THC, 5% (5%-6%) of NOx and 10% (8%-13%) of PM10 estimated total vehicle emissions in 2009. Those controls are essential to further vehicle emission mitigation in Guangzhou

  20. Self-control of traffic lights and vehicle flows in urban road networks

    NASA Astrophysics Data System (ADS)

    Lämmer, Stefan; Helbing, Dirk

    2008-04-01

    Based on fluid-dynamic and many-particle (car-following) simulations of traffic flows in (urban) networks, we study the problem of coordinating incompatible traffic flows at intersections. Inspired by the observation of self-organized oscillations of pedestrian flows at bottlenecks, we propose a self-organization approach to traffic light control. The problem can be treated as a multi-agent problem with interactions between vehicles and traffic lights. Specifically, our approach assumes a priority-based control of traffic lights by the vehicle flows themselves, taking into account short-sighted anticipation of vehicle flows and platoons. The considered local interactions lead to emergent coordination patterns such as 'green waves' and achieve an efficient, decentralized traffic light control. While the proposed self-control adapts flexibly to local flow conditions and often leads to non-cyclical switching patterns with changing service sequences of different traffic flows, an almost periodic service may evolve under certain conditions and suggests the existence of a spontaneous synchronization of traffic lights despite the varying delays due to variable vehicle queues and travel times. The self-organized traffic light control is based on an optimization and a stabilization rule, each of which performs poorly at high utilizations of the road network, while their proper combination reaches a superior performance. The result is a considerable reduction not only in the average travel times, but also of their variation. Similar control approaches could be applied to the coordination of logistic and production processes.

  1. Position and force control of a vehicle with two or more steerable drive wheels

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reister, D.B.; Unseren, M.A.

    1992-10-01

    When a vehicle with two or more steerable drive wheels is traveling in a circle, the motion of the wheels is constrained. The wheel translational velocity divided by the radius to the center of rotation must be the same for all wheels. When the drive wheels are controlled independently using position control, the motion of the wheels may violate the constraints and the wheels may slip. Consequently, substantial errors can occur in the orientation of the vehicle. A vehicle with N drive wheels has (N - 1) constraints and one degree of freedom. We have developed a new approach tomore » the control of a vehicle with N steerable drive wheels. The novel aspect of our approach is the use of force control. To control the vehicle, we have one degree of freedom for the position on the circle and (N - 1) forces that can be used to reduce errors. Recently, Kankaanranta and Koivo developed a control architecture that allows the force and position degrees of freedom to be decoupled. In the work of Kankaanranta and Koivo the force is an exogenous input. We have made the force endogenous by defining the force in terms of the errors in satisfying the rigid body kinematic constraints. We have applied the control architecture to the HERMIES-III robot and have measured a dramatic reduction in error (more than a factor of 20) compared to motions without force control.« less

  2. Aquatic Plant Control Research Program: Effects of Salinity and Irradiance Conditions on the Growth, Morphology and Chemical Composition of Submersed Aquatic Macrophytes

    DTIC Science & Technology

    1990-07-01

    L , AQUATIC PLANT CONTROL RESEARCH PROGRAM * * TECHNICAL REPORT A-90-5 EFFECTS OF SALINITY AND IRRADIANCE CONDITIONS ON THE GROWTH, MORPHOLOGY AND...UNIT ELEMENT NO. NO. NO. ACCESSION NO. 11. TITLE (Indude Security Classification) Effects of Salinity and Irradiance Conditions on the Growth...Dr. Robert W. Whalin. This report should be cited as follows: Twilley, Robert R., and Barko, John W. 1990. " Effects of Salinity and Irradiance

  3. Can you hear me. Noise control regulations for motor vehicles

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Colvin, J.E.

    1976-06-01

    Companies should take action to ensure that their trucks and construction equipment conform to noise regulations established by the Environmental Protection Agency under authority of the 1972 Noise Control Act. Noise control regulations are applicable to all motor carriers with a gross vehicle weight rating of over 10,000 lb, regardless of the date of vehicle manufacture. The standards basically provide for five inspection steps to determine the compliance or non-compliance of a vehicle. Noise measurement tests must be carried out in a specific manner. The EPA has also issued regulations establishing noise emission standards for new medium and heavy trucksmore » over 10,000 lb gross vehicle weight rating and designed for street and highway use. The EPA is also looking into noise emissions from construction equipment; the first of these regulations sets a ceiling on noise emissions for new portable air compressors. In addition to the exterior noise-level limits prescribed by the EPA, the in-cab noise levels are federally regulated from the view-point of occupational noise-exposure criteria. Companies should train personnel in the physical properties of sound and the use of sound-measuring devices to ensure that new and existing equipment complies with the regulations.« less

  4. Air-Breathing Hypersonic Vehicle Tracking Control Based on Adaptive Dynamic Programming.

    PubMed

    Mu, Chaoxu; Ni, Zhen; Sun, Changyin; He, Haibo

    2017-03-01

    In this paper, we propose a data-driven supplementary control approach with adaptive learning capability for air-breathing hypersonic vehicle tracking control based on action-dependent heuristic dynamic programming (ADHDP). The control action is generated by the combination of sliding mode control (SMC) and the ADHDP controller to track the desired velocity and the desired altitude. In particular, the ADHDP controller observes the differences between the actual velocity/altitude and the desired velocity/altitude, and then provides a supplementary control action accordingly. The ADHDP controller does not rely on the accurate mathematical model function and is data driven. Meanwhile, it is capable to adjust its parameters online over time under various working conditions, which is very suitable for hypersonic vehicle system with parameter uncertainties and disturbances. We verify the adaptive supplementary control approach versus the traditional SMC in the cruising flight, and provide three simulation studies to illustrate the improved performance with the proposed approach.

  5. Nonlinear fractional order proportion-integral-derivative active disturbance rejection control method design for hypersonic vehicle attitude control

    NASA Astrophysics Data System (ADS)

    Song, Jia; Wang, Lun; Cai, Guobiao; Qi, Xiaoqiang

    2015-06-01

    Near space hypersonic vehicle model is nonlinear, multivariable and couples in the reentry process, which are challenging for the controller design. In this paper, a nonlinear fractional order proportion integral derivative (NFOPIλDμ) active disturbance rejection control (ADRC) strategy based on a natural selection particle swarm (NSPSO) algorithm is proposed for the hypersonic vehicle flight control. The NFOPIλDμ ADRC method consists of a tracking-differentiator (TD), an NFOPIλDμ controller and an extended state observer (ESO). The NFOPIλDμ controller designed by combining an FOPIλDμ method and a nonlinear states error feedback control law (NLSEF) is to overcome concussion caused by the NLSEF and conversely compensate the insufficiency for relatively simple and rough signal processing caused by the FOPIλDμ method. The TD is applied to coordinate the contradiction between rapidity and overshoot. By attributing all uncertain factors to unknown disturbances, the ESO can achieve dynamic feedback compensation for these disturbances and thus reduce their effects. Simulation results show that the NFOPIλDμ ADRC method can make the hypersonic vehicle six-degree-of-freedom nonlinear model track desired nominal signals accurately and fast, has good stability, dynamic properties and strong robustness against external environmental disturbances.

  6. The estimated reduction in the odds of loss-of-control type crashes for sport utility vehicles equipped with electronic stability control.

    PubMed

    Green, Paul E; Woodrooffe, John

    2006-01-01

    Using data from the NASS General Estimates System (GES), the method of induced exposure was used to assess the effects of electronic stability control (ESC) on loss-of-control type crashes for sport utility vehicles. Sport utility vehicles were classified into crash types generally associated with loss of control and crash types most likely not associated with loss of control. Vehicles were then compared as to whether ESC technology was present or absent in the vehicles. A generalized additive model was fit to assess the effects of ESC, driver age, and driver gender on the odds of loss of control. In addition, the effects of ESC on roads that were not dry were compared to effects on roads that were dry. Overall, the estimated percentage reduction in the odds of a loss-of-control crash for sport utility vehicles equipped with ESC was 70.3%. Both genders and all age groups showed reduced odds of loss-of-control crashes, but there was no significant difference between males and females. With respect to driver age, the maximum percentage reduction of 73.6% occurred at age 27. The positive effects of ESC on roads that were not dry were significantly greater than on roads that were dry.

  7. Driving Performance After Self-Regulated Control Transitions in Highly Automated Vehicles.

    PubMed

    Eriksson, Alexander; Stanton, Neville A

    2017-12-01

    This study aims to explore whether driver-paced, noncritical transitions of control may counteract some of the aftereffects observed in the contemporary literature, resulting in higher levels of vehicle control. Research into control transitions in highly automated driving has focused on urgent scenarios where drivers are given a relatively short time span to respond to a request to resume manual control, resulting in seemingly scrambled control when manual control is resumed. Twenty-six drivers drove two scenarios with an automated driving feature activated. Drivers were asked to read a newspaper or monitor the system and relinquish or resume control from the automation when prompted by vehicle systems. Driving performance in terms of lane positioning and steering behavior was assessed for 20 seconds post resuming control to capture the resulting level of control. It was found that lane positioning was virtually unaffected for the duration of the 20-second time span in both automated conditions compared to the manual baseline when drivers resumed manual control; however, significant increases in the standard deviation of steering input were found for both automated conditions compared to baseline. No significant differences were found between the two automated conditions. The results indicate that when drivers self-paced the transfer back to manual control they exhibit less of the detrimental effects observed in system-paced conditions. It was shown that self-paced transitions could reduce the risk of accidents near the edge of the operational design domain. Vehicle manufacturers must consider these benefits when designing contemporary systems.

  8. Machine & electrical double control air dryer for vehicle air braking system

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan; Yang, Liu; Wang, Xian Yan; Tan, Xiao Yan; Wang, Wei

    2017-09-01

    As is known to all, a vehicle air brake system, in which usually contains moisture. To solve the problem, it is common to use air dryer to dry compressed air effectively and completely remove the moisture and oil of braking system. However, the existing air dryer is not suitable for all commercial vehicles. According to the operational status of the new energy vehicles in the initial operating period, the structure design principle of the machine & electric control air dryer is expounded from the aspects of the structure and operating principle, research & development process.

  9. A semi-active control suspension system for railway vehicles with magnetorheological fluid dampers

    NASA Astrophysics Data System (ADS)

    Wei, Xiukun; Zhu, Ming; Jia, Limin

    2016-07-01

    The high-speed train has achieved great progress in the last decades. It is one of the most important modes of transportation between cities. With the rapid development of the high-speed train, its safety issue is paid much more attention than ever before. To improve the stability of the vehicle with high speed, extra dampers (i.e. anti-hunting damper) are used in the traditional bogies with passive suspension system. However, the curving performance of the vehicle is undermined due to the extra lateral force generated by the dampers. The active suspension systems proposed in the last decades attempt to solve the vehicle steering issue. However, the active suspension systems need extra actuators driven by electrical power or hydraulic power. There are some implementation and even safety issues which are not easy to be overcome. In this paper, an innovative semi-active controlled lateral suspension system for railway vehicles is proposed. Four magnetorheological fluid dampers are fixed to the primary suspension system of each bogie. They are controlled by online controllers for enhancing the running stability on the straight track line on the one hand and further improving the curving performance by controlling the damper force on the other hand. Two control strategies are proposed in the light of the pure rolling concept. The effectiveness of the proposed strategies is demonstrated by SIMPACK and Matlab co-simulation for a full railway vehicle with two conventional bogies.

  10. A combined-slip predictive control of vehicle stability with experimental verification

    NASA Astrophysics Data System (ADS)

    Jalali, Milad; Hashemi, Ehsan; Khajepour, Amir; Chen, Shih-ken; Litkouhi, Bakhtiar

    2018-02-01

    In this paper, a model predictive vehicle stability controller is designed based on a combined-slip LuGre tyre model. Variations in the lateral tyre forces due to changes in tyre slip ratios are considered in the prediction model of the controller. It is observed that the proposed combined-slip controller takes advantage of the more accurate tyre model and can adjust tyre slip ratios based on lateral forces of the front axle. This results in an interesting closed-loop response that challenges the notion of braking only the wheels on one side of the vehicle in differential braking. The performance of the proposed controller is evaluated in software simulations and is compared to a similar pure-slip controller. Furthermore, experimental tests are conducted on a rear-wheel drive electric Chevrolet Equinox equipped with differential brakes to evaluate the closed-loop response of the model predictive control controller.

  11. Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles

    PubMed Central

    Olivares-Mendez, Miguel Angel; Sanchez-Lopez, Jose Luis; Jimenez, Felipe; Campoy, Pascual; Sajadi-Alamdari, Seyed Amin; Voos, Holger

    2016-01-01

    Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption. PMID:26978365

  12. Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles.

    PubMed

    Olivares-Mendez, Miguel Angel; Sanchez-Lopez, Jose Luis; Jimenez, Felipe; Campoy, Pascual; Sajadi-Alamdari, Seyed Amin; Voos, Holger

    2016-03-11

    Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption.

  13. Traffic signal control enhancements under vehicle infrastructure integration systems.

    DOT National Transportation Integrated Search

    2011-12-01

    Most current traffic signal systems are operated using a very archaic traffic-detection simple binary : logic (vehicle presence/non presence information). The logic was originally developed to provide input for old : electro-mechanical controllers th...

  14. Estuarine Salinity Mapping From Airborne Radiometry

    NASA Astrophysics Data System (ADS)

    Walker, J. P.; Gao, Y.; Cook, P. L. M.; Ye, N.

    2016-12-01

    Estuaries are critical ecosystems providing both ecological habitat and human amenity including boating and recreational fishing. Salinity gradients, caused by the mixing of fresh and salt water, exert an overwhelming control on estuarine ecology and biogeochemistry as well as being a key tracer for model calibration. At present, salinity monitoring within estuaries typically uses point measurements or underway boat-based methods, which makes sensing of localised phenomena such as upwelling of saline bottom water difficult. This study has pioneered the use of airborne radiometry (passive microwave) sensing as a new method to remotely quantify estuarine salinity, allowing rapid production of high resolution surface salinity maps. The airborne radiometry mapping was conducted for the Gippsland Lakes, the largest estuary in Australia, in February, July, October and November of 2015, using the Polarimetric L-band Microwave Radiometer (PLMR). Salinity was retrieved from the brightness temperature collected by PLMR with results validated against boat sampling conducted concurrently with each flight. Results showed that the retrieval accuracy of the radiative transfer model was better than 5 ppt for most flights. The spatial, temporal and seasonal variations of salinity observed in this study are also analysed and discussed.

  15. Evaluation of some significant issues affecting trajectory and control management for air-breathing hypersonic vehicles

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1992-01-01

    Horizontal takeoff airbreathing-propulsion launch vehicles require near-optimal guidance and control which takes into account performance sensitivities to atmospheric characteristics while satisfying physically-derived operational constraints. A generic trajectory/control analysis tool that deepens insight into these considerations has been applied to two versions of a winged-cone vehicle model. Information that is critical to the design and trajectory of these vehicles is derived, and several unusual characteristics of the airbreathing propulsion model are shown to have potentially substantial effects on vehicle dynamics.

  16. Research on charging and discharging control strategy for electric vehicles as distributed energy storage devices

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Yang, Feng; Zhang, Dongqing; Tang, Pengcheng

    2018-02-01

    A large number of electric vehicles are connected to the family micro grid will affect the operation safety of the power grid and the quality of power. Considering the factors of family micro grid price and electric vehicle as a distributed energy storage device, a two stage optimization model is established, and the improved discrete binary particle swarm optimization algorithm is used to optimize the parameters in the model. The proposed control strategy of electric vehicle charging and discharging is of practical significance for the rational control of electric vehicle as a distributed energy storage device and electric vehicle participating in the peak load regulation of power consumption.

  17. Design of Genetic Algorithms for Topology Control of Unmanned Vehicles

    DTIC Science & Technology

    2010-01-01

    decentralised topology control mechanism distributed among active running software agents to achieve a uniform spread of terrestrial unmanned vehicles...14. ABSTRACT We present genetic algorithms (GAs) as a decentralised topology control mechanism distributed among active running software agents to...inspired topology control algorithm. The topology control of UVs using a decentralised solution over an unknown geographical terrain is a challenging

  18. A Feedforward Control Approach to the Local Navigation Problem for Autonomous Vehicles

    DTIC Science & Technology

    1994-05-02

    AD-A282 787 " A Feedforward Control Approach to the Local Navigation Problem for Autonomous Vehicles Alonzo Kelly CMU-RI-TR-94-17 The Robotics...follow, or a direction to prefer, it cannot generate its own strategic goals. Therefore, it solves the local planning problem for autonomous vehicles . The... autonomous vehicles . It is intelligent because it uses range images that are generated from either a laser rangefinder or a stereo triangulation

  19. Development of wireless vehicle remote control for fuel lid operation

    NASA Astrophysics Data System (ADS)

    Sulaiman, N.; Jadin, M. S.; Najib, M. S.; Mustafa, M.; Azmi, S. N. F.

    2018-04-01

    Nowadays, the evolution of the vehicle technology had made the vehicle especially car to be equipped with a remote control to control the operation of the locking and unlocking system of the car’s door and rear’s bonnet. However, for the fuel or petrol lid, it merely can be opened from inside the car’s cabin by handling the fuel level inside the car’s cabin to open the fuel lid. The petrol lid can be closed by pushing the lid by hand. Due to the high usage of using fuel lever to open the fuel lid when refilling the fuel, the car driver might encounter the malfunction of fuel lid (fail to open) when pushing or pulling the fuel lever. Thus, the main aim of the research is to enhance the operation of an existing car remote control where the car fuel lid can be controlled using two techniques; remote control-based and smartphone-based. The remote control is constructed using Arduino microcontroller, wireless sensors and XCTU software to set the transmitting and receiving parameters. Meanwhile, the smartphone can control the operation of the fuel lid by communicating with Arduino microcontroller which is attached to the fuel lid using Bluetooth sensor to open the petrol lid. In order to avoid the conflict of instruction between wireless systems with the existing mechanical-based system, the servo motor will be employed to release the fuel lid merely after receiving the instruction from Arduino microcontroller and smartphone. As a conclusion, the prototype of the multipurpose vehicle remote control is successfully invented, constructed and tested. The car fuel lid can be opened either using remote control or smartphone in a sequential manner. Therefore, the outcome of the project can be used to serve as an alternative solution to solve the car fuel lid problem even though the problem rarely occurred.

  20. The effects of in-vehicle tasks and time-gap selection while reclaiming control from adaptive cruise control (ACC) with bus simulator.

    PubMed

    Lin, Tsang-Wei; Hwang, Sheue-Ling; Su, Jau-Ming; Chen, Wan-Hui

    2008-05-01

    This research aimed to find out the effects of in-vehicle distractions and time-gap settings with a fix-based bus driving simulator in a following scenario. Professional bus drivers were recruited to perform in-vehicle tasks while driving with adaptive cruise control (ACC) of changeable time-gap settings in freeway traffic. Thirty subjects were divided equally into three groups for different in-vehicle task modes (between subjects), including no task distraction, hands-free, and manual modes. Further, time-gap settings for the experimental ACC were: shorter than 1.0 s, 1.0-1.5 s, 1.5-2.0 s, and longer than 2.0 s (within subjects). Longitudinal (mean headway, forward collision rate, and response time) and lateral control (mean lateral lane position and its standard deviation) performance was assessed. In the results, longitudinal control performance was worsened by both shorter time-gaps and heavier in-vehicle tasks. But the interaction indicated that the harm by heavier in-vehicle distraction could be improved by longer time-gaps. As for the lateral control, it would only be negatively affected by shorter time-gap settings. This research indicates the effects of time-gaps and in-vehicle distraction, as well as the interaction. Proper time-gap selection under different in-vehicle distractions can help avoid accidents and keep safe.

  1. Change control microcomputer device for vehicle

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Morishita, M.; Kouge, S.

    1986-08-19

    A charge control microcomputer device for a vehicle is described which consists of: a clutch device for transmitting the rotary output of an engine; a charging generator driven by the clutch device; a battery charged by an output of the charging generator; a voltage regulator for controlling an output voltage of the charging generator to a predetermined value; an engine controlling microcomputer for receiving engine data, to control the engine; and a charge control microcomputer for processing the engine data from the engine controlling microcomputer and charge system data including terminal voltage data from the battery and generated voltage datamore » from the charging generator, to determine a reference voltage for the voltage regulator in accordance with the engine data and the charge system data, and for processing an engine rotation signal to generate and apply an operating instruction to the clutch device in accordance with the engine data and the charge system data, such that the charging generator is driven within a predetermined range of revolutions per minute at all times.« less

  2. Intravenous versus intramuscular cobinamide compared to intravenous saline (control) in the treatment of acute, survivable, mitochondrial toxins in swine (Sus Scrofa): a pilot study

    DTIC Science & Technology

    2018-04-10

    Type of Research: Animal Research 3. Title: Intravenous versus intramuscular cobinamide compared to intravenous saline ( control ) in the treatment...the hyperkalemia under control and in our upcoming protocol we feel we will finally be able to induce apnea with the toxin and calcium channel...intramuscular cobinamide compared to intravenous saline ( control ) in the treatment of acute, survivable, mitochondrial toxins in swine (Sus Scrofa): a pilot

  3. Vehicle dynamics control by using a three-dimensional stabilizer pendulum system

    NASA Astrophysics Data System (ADS)

    Goodarzi, A.; Naghibian, M.; Choodan, D.; Khajepour, A.

    2016-12-01

    Active safety systems of a vehicle normally work well on tyre-road interactions, however, these systems deteriorate in performance on low-friction road conditions. To combat this effect, an innovative idea for the yaw moment and roll dynamic control is presented in this paper. This idea was inspired by the chase and run dynamics animals like cheetahs in the nature; cheetahs have the ability to swerve while running at very high speeds. A cheetah controls its dynamics by rotating its long tail. A three-dimensional stabilizer pendulum system (3D-SPS) resembles the rotational motion of the tail of a cheetah to improve the stability and safety of a vehicle. The idea has been developed in a stand-alone 3D stabilizer pendulum system as well as in an integrated control system, which consists of an ordinary differential braking direct yaw control (DYC) and active steering control that is assisted by the 3D-SPS. The performance of the proposed 3D-SPS has been evaluated over a wide range of handling manoeuvres by using a comprehensive numerical simulation. The results show the advantage of 3D-SPS over conventional control approaches, which are ineffective on low-friction road conditions and high lateral acceleration manoeuvres. It should however be noted that the best vehicle dynamics performance is obtained when an integrated 3D-SPS and DYC and AFS is utilised.

  4. Utilizing adaptive wing technology in the control of a micro air vehicle

    NASA Astrophysics Data System (ADS)

    Null, William R.; Wagner, Matthew G.; Shkarayev, Sergey V.; Jouse, Wayne C.; Brock, Keith M.

    2002-07-01

    Evolution of the design of micro air vehicles (MAVs) towards miniaturization has been severely constrained by the size and mass of the electronic components needed to control the vehicles. Recent research, experimentation, and development in the area of smart materials have led to the possibility of embedding control actuators, fabricated from smart materials, in the wing of the vehicle, reducing both the size and mass of these components. Further advantages can be realized by developing adaptive wing structures. Small size and mass, and low airspeeds, can lead to considerable buffeting during flight, and may result in a loss of flight control. In order to counter these effects, we are developing a thin, variable-cambered airfoil design with actuators embedded within the wing. In addition to reducing the mass and size of the vehicle or, conversely, increasing its available payload, an important benefit from the adaptive wing concept is the possibility of in-flight modification of the flight envelope. Reduced airspeeds, which are crucial during loiter, can be realized by an in-flight increase in wing camber. Conversely, decreases in camber provide for an airframe best suited for rapid ingress/egress and extension of the mission range.

  5. The manual control of vehicles undergoing slow transitions in dynamic characteristics

    NASA Technical Reports Server (NTRS)

    Moriarty, T. E.

    1974-01-01

    The manual control was studied of a vehicle with slowly time-varying dynamics to develop analytic and computer techniques necessary for the study of time-varying systems. The human operator is considered as he controls a time-varying plant in which the changes are neither abrupt nor so slow that the time variations are unimportant. An experiment in which pilots controlled the longitudinal mode of a simulated time-varying aircraft is described. The vehicle changed from a pure double integrator to a damped second order system, either instantaneously or smoothly over time intervals of 30, 75, or 120 seconds. The regulator task consisted of trying to null the error term resulting from injected random disturbances with bandwidths of 0.8, 1.4, and 2.0 radians per second. Each of the twelve experimental conditons was replicated ten times. It is shown that the pilot's performance in the time-varying task is essentially equivalent to his performance in stationary tasks which correspond to various points in the transition. A rudimentary model for the pilot-vehicle-regulator is presented.

  6. Road load simulator tests of the Gould phase 1 functional model silicon controlled rectifier ac motor controller for electric vehicles

    NASA Astrophysics Data System (ADS)

    Gourash, F.

    1984-02-01

    The test results for a functional model ac motor controller for electric vehicles and a three-phase induction motor which were dynamically tested on the Lewis Research Center road load simulator are presented. Results show that the controller has the capability to meet the SAE-J227a D cycle test schedule and to accelerate a 1576-kg (3456-lb) simulated vehicle to a cruise speed of 88.5 km/hr (55 mph). Combined motor controller efficiency is 72 percent and the power inverter efficiency alone is 89 percent for the cruise region of the D cycle. Steady state test results for motoring, regeneration, and thermal data obtained by operating the simulator as a conventional dynamometer are in agreement with the contractor's previously reported data. The regeneration test results indicate that a reduction in energy requirements for urban driving cycles is attainable with regenerative braking. Test results and data in this report serve as a data base for further development of ac motor controllers and propulsion systems for electric vehicles. The controller uses state-of-the-art silicon controlled rectifier (SCR) power semiconductors and microprocessor-based logic and control circuitry. The controller was developed by Gould Laboratories under a Lewis contract for the Department of Energy's Electric and Hybrid Vehicle program.

  7. Road load simulator tests of the Gould phase 1 functional model silicon controlled rectifier ac motor controller for electric vehicles

    NASA Technical Reports Server (NTRS)

    Gourash, F.

    1984-01-01

    The test results for a functional model ac motor controller for electric vehicles and a three-phase induction motor which were dynamically tested on the Lewis Research Center road load simulator are presented. Results show that the controller has the capability to meet the SAE-J227a D cycle test schedule and to accelerate a 1576-kg (3456-lb) simulated vehicle to a cruise speed of 88.5 km/hr (55 mph). Combined motor controller efficiency is 72 percent and the power inverter efficiency alone is 89 percent for the cruise region of the D cycle. Steady state test results for motoring, regeneration, and thermal data obtained by operating the simulator as a conventional dynamometer are in agreement with the contractor's previously reported data. The regeneration test results indicate that a reduction in energy requirements for urban driving cycles is attainable with regenerative braking. Test results and data in this report serve as a data base for further development of ac motor controllers and propulsion systems for electric vehicles. The controller uses state-of-the-art silicon controlled rectifier (SCR) power semiconductors and microprocessor-based logic and control circuitry. The controller was developed by Gould Laboratories under a Lewis contract for the Department of Energy's Electric and Hybrid Vehicle program.

  8. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle.

    PubMed

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  9. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    PubMed Central

    Peng, Jiankun; He, Hongwen; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved. PMID:26236772

  10. Environmental Control and Life Support (ECLS) Hardware Commonality for Exploration Vehicles

    NASA Technical Reports Server (NTRS)

    Carrasquillo, Robyn; Anderson, Molly

    2012-01-01

    In August 2011, the Environmental Control and Life Support Systems (ECLSS) technical community, along with associated stakeholders, held a workshop to review NASA s plans for Exploration missions and vehicles with two objectives: revisit the Exploration Atmospheres Working Group (EAWG) findings from 2006, and discuss preliminary ECLSS architecture concepts and technology choices for Exploration vehicles, identifying areas for potential common hardware or technologies to be utilized. Key considerations for selection of vehicle design total pressure and percent oxygen include operational concepts for extravehicular activity (EVA) and prebreathe protocols, materials flammability, and controllability within pressure and oxygen ranges. New data for these areas since the 2006 study were presented and discussed, and the community reached consensus on conclusions and recommendations for target design pressures for each Exploration vehicle concept. For the commonality study, the workshop identified many areas of potential commonality across the Exploration vehicles as well as with heritage International Space Station (ISS) and Shuttle hardware. Of the 36 ECLSS functions reviewed, 16 were considered to have strong potential for commonality, 13 were considered to have some potential commonality, and 7 were considered to have limited potential for commonality due to unique requirements or lack of sufficient heritage hardware. These findings, which will be utilized in architecture studies and budget exercises going forward, are presented in detail.

  11. Variable Speed CMG Control of a Dual-Spin Stabilized Unconventional VTOL Air Vehicle

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Moerder, Daniel D.; Shin, J-Y.

    2004-01-01

    This paper describes an approach based on using both bias momentum and multiple control moment gyros for controlling the attitude of statically unstable thrust-levitated vehicles in hover or slow translation. The stabilization approach described in this paper uses these internal angular momentum transfer devices for stability, augmented by thrust vectoring for trim and other outer loop control functions, including CMG stabilization/ desaturation under persistent external disturbances. Simulation results show the feasibility of (1) improved vehicle performance beyond bias momentum assisted vector thrusting control, and (2) using control moment gyros to significantly reduce the external torque required from the vector thrusting machinery.

  12. Lane changing trajectory planning and tracking control for intelligent vehicle on curved road.

    PubMed

    Wang, Lukun; Zhao, Xiaoying; Su, Hao; Tang, Gongyou

    2016-01-01

    This paper explores lane changing trajectory planning and tracking control for intelligent vehicle on curved road. A novel arcs trajectory is planned for the desired lane changing trajectory. A kinematic controller and a dynamics controller are designed to implement the trajectory tracking control. Firstly, the kinematic model and dynamics model of intelligent vehicle with non-holonomic constraint are established. Secondly, two constraints of lane changing on curved road in practice (LCCP) are proposed. Thirdly, two arcs with same curvature are constructed for the desired lane changing trajectory. According to the geometrical characteristics of arcs trajectory, equations of desired state can be calculated. Finally, the backstepping method is employed to design a kinematic trajectory tracking controller. Then the sliding-mode dynamics controller is designed to ensure that the motion of the intelligent vehicle can follow the desired velocity generated by kinematic controller. The stability of control system is proved by Lyapunov theory. Computer simulation demonstrates that the desired arcs trajectory and state curves with B-spline optimization can meet the requirements of LCCP constraints and the proposed control schemes can make tracking errors to converge uniformly.

  13. Palaeohydrological evolution of the late Cenozoic saline lake in the Qaidam Basin, NE Tibetan Plateau: Tectonic vs. climatic control

    NASA Astrophysics Data System (ADS)

    Guo, Pei; Liu, Chiyang; Huang, Lei; Yu, Mengli; Wang, Peng; Zhang, Guoqing

    2018-06-01

    As the largest Cenozoic terrestrial intermountain basin on the Tibetan Plateau, the Qaidam Basin is an ideal setting to understand the coupled controls of tectonics and climate on hydrological evolution. In this study, we used 47,846 data of carbonate and chloride contents from 146 boreholes to reconstruct the Neogene-Quaternary basin-wide hydrological evolution of the Qaidam Basin. Our results show that during the early Miocene (22-15 Ma), the palaeolake in the Qaidam Basin was mainly situated in the southwestern part of the basin, and its water was mostly brackish. From then on, this palaeolake progressively migrated southeastward, and its salinity increased from late Miocene saline water to Quaternary brines. This generally increasing trend of the water palaeosalinity during the late Cenozoic corresponded with regional and global climate changes at that time, suggesting the dominance of climatic control. However, the paces of the salinity increase from sediments in front of the three basin-bounding ranges were not the same, indicating that extra tectonic controls occurred. Sediments in front of the Eastern Kunlun Shan to the southwest and the Altyn Shan to the northwest showed an abrupt, dramatic increase in salinity at 15 Ma and 8 Ma, respectively; sediments in front of the Qilian Shan to the northeast showed steady increase without prominent, abrupt changes, indicating the occurrence of asynchronous tectonic controls from the basin-bounding ranges. The late Miocene depocentre migration was synchronous with the hydrological changes in front of the Altyn Shan, while the more significant migration during the Quaternary was consistent with the pulsing, intense extrabasinal and intrabasinal tectonic movements along the Tibetan Plateau.

  14. Aerodynamic Control-Augmentation Devices For Saturn-Class Launch Vehicles With Aft Centers Of Gravity

    NASA Technical Reports Server (NTRS)

    Barret, Chris

    1995-01-01

    Report describes study of aerodynamic flight-control-augmentation devices proposed for use in increasing payload capabilities of future launch vehicles by allowing more aft centers of gravity. Proposed all-movable devices not only provide increased control authority during ascent trajectory, but also reduce engine gimballing requirements and enhance crew safety. Report proposes various aerodynamic control surfaces mounted fore and aft on Saturn-class launch vehicle.

  15. Hypersonic Vehicle Trajectory Optimization and Control

    NASA Technical Reports Server (NTRS)

    Balakrishnan, S. N.; Shen, J.; Grohs, J. R.

    1997-01-01

    Two classes of neural networks have been developed for the study of hypersonic vehicle trajectory optimization and control. The first one is called an 'adaptive critic'. The uniqueness and main features of this approach are that: (1) they need no external training; (2) they allow variability of initial conditions; and (3) they can serve as feedback control. This is used to solve a 'free final time' two-point boundary value problem that maximizes the mass at the rocket burn-out while satisfying the pre-specified burn-out conditions in velocity, flightpath angle, and altitude. The second neural network is a recurrent network. An interesting feature of this network formulation is that when its inputs are the coefficients of the dynamics and control matrices, the network outputs are the Kalman sequences (with a quadratic cost function); the same network is also used for identifying the coefficients of the dynamics and control matrices. Consequently, we can use it to control a system whose parameters are uncertain. Numerical results are presented which illustrate the potential of these methods.

  16. Fever control and application of hypothermia using intravenous cold saline

    PubMed Central

    Fink, Ericka L.; Kochanek, Patrick M.; Clark, Robert S. B.; Bell, Michael J.

    2013-01-01

    Objective To describe the use and feasibility of cold saline to decrease body temperature in pediatric neurocritical care. Design Retrospective chart review. Setting Pediatric tertiary care university hospital. Patients Children between 1 week and 17 yrs of age admitted to the pediatric intensive care unit with acute brain injury and having received intravenous cold saline between June-August 2009. Intervention(s) None. Measurements and Main Results Eighteen subjects accounted for 20 infusions with mean infusion volume 18 ± 10 cc/kg. Eight subjects had traumatic brain injury (TBI), 2 had intracranial hemorrhage, 6 had cardiac arrest, and one each had ischemic stroke and status epilepticus. The mean age was 9.5 ± 4.8 yrs. Temperature decreased from 38.7 ± 1.1°C to 37.7 ± 1.2°C and 37.0 ± 2.0 to 35.3 ± 1.6°C one h after infusion for fever (n=14, p<.05) or hypothermia (HT) induction (n=6, p=.05), respectively. Cold saline was not bolused, rather infused over 10–15 minutes. Mean arterial blood pressure and oxygenation parameters (PaO2/FiO2 ratio, mean airway pressure) were unchanged, but heart rate decreased in HT subjects (121 ± 4 vs. 109 ± 12; p<.05). Serum sodium concentration and International normalized ratio were significantly increased after cold saline infusion. There were no differences between pre- and post-infusion serum glucose and hematocrit, nor cerebral perfusion pressure or intracranial pressure in TBI patients. Conclusions Cold saline was an effective method of reducing temperature in children with acute brain injury. This approach can be considered to treat fever or to induce HT. Prospective study comparing safety and efficacy versus other cooling measures should be considered. PMID:21037507

  17. A driver-adaptive stability control strategy for sport utility vehicles

    NASA Astrophysics Data System (ADS)

    Zhu, Shenjin; He, Yuping

    2017-08-01

    Conventional vehicle stability control (VSC) systems are designed for average drivers. For a driver with a good driving skill, the VSC systems may be redundant; for a driver with a poor driving skill, the VSC intervention may be inadequate. To increase safety of sport utility vehicles (SUVs), this paper proposes a novel driver-adaptive VSC (DAVSC) strategy based on scaling the target yaw rate commanded by the driver. The DAVSC system is adaptive to drivers' driving skills. More control effort would be exerted for drivers with poor driving skills, and vice versa. A sliding mode control (SMC)-based differential braking (DB) controller is designed using a three degrees of freedom (DOF) yaw-plane model. An eight DOF nonlinear yaw-roll model is used to simulate the SUV dynamics. Two driver models, namely longitudinal and lateral, are used to 'drive' the virtual SUV. By integrating the virtual SUV, the DB controller, and the driver models, the performance of the DAVSC system is investigated. The simulations demonstrate the effectiveness of the DAVSC strategy.

  18. Stability and Control Properties of an Aeroelastic Fixed Wing Micro Aerial Vehicle

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R.; Jenkins, Luther N.; Ifju, Peter

    2001-01-01

    Micro aerial vehicles have been the subject of considerable interest and development over the last several years. The majority of current vehicle concepts rely on rigid fixed wings or rotors. An alternate design based on an aeroelastic membrane wing concept has also been developed that has exhibited desired characteristics in flight test demonstrations and competition. This paper presents results from a wind tunnel investigation that sought to quantify stability and control properties for a family of vehicles using the aeroelastic design. The results indicate that the membrane wing does exhibit potential benefits that could be exploited to enhance the design of future flight vehicles.

  19. Fault-Tolerant and Reconfigurable Control of Unmanned Aerial Vehicles (UAVs)

    DTIC Science & Technology

    2008-02-29

    forces and moments are expressed as functions of angle of attack, sideslip angle, angular rates, and control surface deflection. L, M, and N are...invertible. As for matrix B, the control surfaces of the reusable launch vehicle are designed to control each axes angular rate of aircraft...literature as being invertible. As for matrix B, the control surfaces of the UAV are designed to control angular rate along each axis of the aircraft

  20. Climate Control Load Reduction Strategies for Electric Drive Vehicles in Cold Weather: Preprint

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jeffers, Matthew; Chaney, Lawrence; Rugh, John

    When operated, the climate control system is the largest auxiliary load on a vehicle. This load has significant impact on fuel economy for conventional and hybrid vehicles, and it drastically reduces the driving range of all electric vehicles (EVs). Heating is even more detrimental to EV range than cooling because no engine waste heat is available. Reducing the thermal loads on the heating, ventilating, and air conditioning system will extend driving range and increase the market penetration of EVs. Researchers at the National Renewable Energy Laboratory have evaluated strategies for vehicle climate control load reduction with special attention toward gridmore » connected electric vehicles. Outdoor vehicle thermal testing and computational modeling were used to assess potential strategies for improved thermal management and to evaluate the effectiveness of thermal load reduction technologies. A human physiology model was also used to evaluate the impact on occupant thermal comfort. Experimental evaluations of zonal heating strategies demonstrated a 5.5% to 28.5% reduction in cabin heating energy over a 20-minute warm-up. Vehicle simulations over various drive cycles show a 6.9% to 18.7% improvement in EV range over baseline heating using the most promising zonal heating strategy investigated. A national-level analysis was conducted to determine the overall national impact. If all vehicles used the best zonal strategy, the range would be improved by 7.1% over the baseline heating range. This is a 33% reduction in the range penalty for heating.« less

  1. Multi Purpose Crew Vehicle Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Cross, Cynthia D.; Rains, George Edward

    2012-01-01

    The Orion Multi Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in 2014. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the completing the components which are on EFT1. Additional development work has been done to keep the remaining component progressing towards implementation for a flight tests in of EM1 in 2017 and in and EM2 in 2020. This paper covers the Orion ECLS development from April 2012 to April 2013.

  2. L1 Adaptive Control Law for Flexible Space Launch Vehicle and Proposed Plan for Flight Test Validation

    NASA Technical Reports Server (NTRS)

    Kharisov, Evgeny; Gregory, Irene M.; Cao, Chengyu; Hovakimyan, Naira

    2008-01-01

    This paper explores application of the L1 adaptive control architecture to a generic flexible Crew Launch Vehicle (CLV). Adaptive control has the potential to improve performance and enhance safety of space vehicles that often operate in very unforgiving and occasionally highly uncertain environments. NASA s development of the next generation space launch vehicles presents an opportunity for adaptive control to contribute to improved performance of this statically unstable vehicle with low damping and low bending frequency flexible dynamics. In this paper, we consider the L1 adaptive output feedback controller to control the low frequency structural modes and propose steps to validate the adaptive controller performance utilizing one of the experimental test flights for the CLV Ares-I Program.

  3. Robust Adaptive Flight Control Design of Air-breathing Hypersonic Vehicles

    DTIC Science & Technology

    2016-12-07

    dynamic inversion controller design for a non -minimum phase hypersonic vehicle is derived by Kuipers et al. [2008]. Moreover, integrated guidance and...stabilization time for inner loop variables is lesser than the intermediate loop variables because of the three-loop-control design methodology . The control...adaptive design . Control Engineering Practice, 2016. Michael A Bolender and David B Doman. A non -linear model for the longitudinal dynamics of a

  4. Robust intelligent flight control for hypersonic vehicles. Ph.D. Thesis - Massachusetts Inst. of Technology

    NASA Technical Reports Server (NTRS)

    Chamitoff, Gregory Errol

    1992-01-01

    Intelligent optimization methods are applied to the problem of real-time flight control for a class of airbreathing hypersonic vehicles (AHSV). The extreme flight conditions that will be encountered by single-stage-to-orbit vehicles, such as the National Aerospace Plane, present a tremendous challenge to the entire spectrum of aerospace technologies. Flight control for these vehicles is particularly difficult due to the combination of nonlinear dynamics, complex constraints, and parametric uncertainty. An approach that utilizes all available a priori and in-flight information to perform robust, real time, short-term trajectory planning is presented.

  5. Analysis and design of a capsule landing system and surface vehicle control system for Mars exporation

    NASA Technical Reports Server (NTRS)

    Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

    1972-01-01

    The problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars were investigated. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; navigation, terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks were studied: vehicle model design, mathematical modeling of dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer subsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement and transport parameter evaluation.

  6. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

    NASA Technical Reports Server (NTRS)

    Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

    1972-01-01

    Investigation of problems related to the design and control of a mobile planetary vehicle to implement a systematic plan for the exploration of Mars has been undertaken. Problem areas receiving attention include: vehicle configuration, control, dynamics, systems and propulsion; systems analysis; terrain modeling and path selection; and chemical analysis of specimens. The following specific tasks have been under study: vehicle model design, mathematical modeling of a dynamic vehicle, experimental vehicle dynamics, obstacle negotiation, electromechanical controls, collapsibility and deployment, construction of a wheel tester, wheel analysis, payload design, system design optimization, effect of design assumptions, accessory optimal design, on-board computer sybsystem, laser range measurement, discrete obstacle detection, obstacle detection systems, terrain modeling, path selection system simulation and evaluation, gas chromatograph/mass spectrometer system concepts, chromatograph model evaluation and improvement.

  7. How human drivers control their vehicle

    NASA Astrophysics Data System (ADS)

    Wagner, P.

    2006-08-01

    The data presented here show that human drivers apply a discrete noisy control mechanism to drive their vehicle. A car-following model built on these observations, together with some physical limitations (crash-freeness, acceleration), lead to non-Gaussian probability distributions in the speed difference and distance which are in good agreement with empirical data. All model parameters have a clear physical meaning and can be measured. Despite its apparent complexity, this model is simple to understand and might serve as a starting point to develop even quantitatively correct models.

  8. Orion Multi-Purpose Crew Vehicle Active Thermal Control and Environmental Control and Life Support Development Status

    NASA Technical Reports Server (NTRS)

    Lewis, John F.; Barido, Richard A.; Cross, Cynthia D.; Rains, George Edward

    2013-01-01

    The Orion Multi-Purpose Crew Vehicle (MPCV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. Orion is currently being developed to transport the crew safely beyond Earth orbit. This year, the vehicle focused on building the Exploration Flight Test 1 (EFT1) vehicle to be launched in 2014. The development of the Orion Environmental Control and Life Support (ECLS) System, focused on the completing the components which are on EFT1. Additional development work has been done to keep the remaining component progressing towards implementation for a flight tests in of EM1 in 2017 and in and EM2 in 2020. This paper covers the Orion ECLS development from April 2012 to April 2013.

  9. A Descent Rate Control Approach to Developing an Autonomous Descent Vehicle

    NASA Astrophysics Data System (ADS)

    Fields, Travis D.

    Circular parachutes have been used for aerial payload/personnel deliveries for over 100 years. In the past two decades, significant work has been done to improve the landing accuracies of cargo deliveries for humanitarian and military applications. This dissertation discusses the approach developed in which a circular parachute is used in conjunction with an electro-mechanical reefing system to manipulate the landing location. Rather than attempt to steer the autonomous descent vehicle directly, control of the landing location is accomplished by modifying the amount of time spent in a particular wind layer. Descent rate control is performed by reversibly reefing the parachute canopy. The first stage of the research investigated the use of a single actuation during descent (with periodic updates), in conjunction with a curvilinear target. Simulation results using real-world wind data are presented, illustrating the utility of the methodology developed. Additionally, hardware development and flight-testing of the single actuation autonomous descent vehicle are presented. The next phase of the research focuses on expanding the single actuation descent rate control methodology to incorporate a multi-actuation path-planning system. By modifying the parachute size throughout the descent, the controllability of the system greatly increases. The trajectory planning methodology developed provides a robust approach to accurately manipulate the landing location of the vehicle. The primary benefits of this system are the inherent robustness to release location errors and the ability to overcome vehicle uncertainties (mass, parachute size, etc.). A separate application of the path-planning methodology is also presented. An in-flight path-prediction system was developed for use in high-altitude ballooning by utilizing the path-planning methodology developed for descent vehicles. The developed onboard system improves landing location predictions in-flight using collected flight

  10. Thermal Control System Development to Support the Crew Exploration Vehicle and Lunar Surface Access Module

    NASA Technical Reports Server (NTRS)

    Anderson, Molly; Westheimer, David

    2006-01-01

    All space vehicles or habitats require thermal management to maintain a safe and operational environment for both crew and hardware. Active Thermal Control Systems (ATCS) perform the functions of acquiring heat from both crew and hardware within a vehicle, transporting that heat throughout the vehicle, and finally rejecting that energy into space. Almost all of the energy used in a space vehicle eventually turns into heat, which must be rejected in order to maintain an energy balance and temperature control of the vehicle. For crewed vehicles, Active Thermal Control Systems are pumped fluid loops that are made up of components designed to perform these functions. NASA has recently evaluated all of the agency s technology development work and identified key areas that must be addressed to aid in the successful development of a Crew Exploration Vehicle (CEV) and a Lunar Surface Access Module (LSAM). The technologies that have been selected and are currently under development include: fluids that enable single loop ATCS architectures, a gravity insensitive vapor compression cycle heat pump, a sublimator with reduced sensitivity to feedwater contamination, an evaporative heat sink that can operate in multiple ambient pressure environments, a compact spray evaporator, and lightweight radiators that take advantage of carbon composites and advanced optical coatings.

  11. Electric power processing, distribution and control for advanced aerospace vehicles.

    NASA Technical Reports Server (NTRS)

    Krausz, A.; Felch, J. L.

    1972-01-01

    The results of a current study program to develop a rational basis for selection of power processing, distribution, and control configurations for future aerospace vehicles including the Space Station, Space Shuttle, and high-performance aircraft are presented. Within the constraints imposed by the characteristics of power generation subsystems and the load utilization equipment requirements, the power processing, distribution and control subsystem can be optimized by selection of the proper distribution voltage, frequency, and overload/fault protection method. It is shown that, for large space vehicles which rely on static energy conversion to provide electric power, high-voltage dc distribution (above 100 V dc) is preferable to conventional 28 V dc and 115 V ac distribution per MIL-STD-704A. High-voltage dc also has advantages over conventional constant frequency ac systems in many aircraft applications due to the elimination of speed control, wave shaping, and synchronization equipment.

  12. Vehicle electrical system state controller

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bissontz, Jay E.

    A motor vehicle electrical power distribution system includes a plurality of distribution sub-systems, an electrical power storage sub-system and a plurality of switching devices for selective connection of elements of and loads on the power distribution system to the electrical power storage sub-system. A state transition initiator provides inputs to control system operation of switching devices to change the states of the power distribution system. The state transition initiator has a plurality of positions selection of which can initiate a state transition. The state transition initiator can emulate a four position rotary ignition switch. Fail safe power cutoff switches providemore » high voltage switching device protection.« less

  13. On-road vehicle emissions and their control in China: A review and outlook.

    PubMed

    Wu, Ye; Zhang, Shaojun; Hao, Jiming; Liu, Huan; Wu, Xiaomeng; Hu, Jingnan; Walsh, Michael P; Wallington, Timothy J; Zhang, K Max; Stevanovic, Svetlana

    2017-01-01

    The large (26-fold over the past 25years) increase in the on-road vehicle fleet in China has raised sustainability concerns regarding air pollution prevention, energy conservation, and climate change mitigation. China has established integrated emission control policies and measures since the 1990s, including implementation of emission standards for new vehicles, inspection and maintenance programs for in-use vehicles, improvement in fuel quality, promotion of sustainable transportation and alternative fuel vehicles, and traffic management programs. As a result, emissions of major air pollutants from on-road vehicles in China have peaked and are now declining despite increasing vehicle population. As might be expected, progress in addressing vehicle emissions has not always been smooth and challenges such as the lack of low sulfur fuels, frauds over production conformity and in-use inspection tests, and unreliable retrofit programs have been encountered. Considering the high emission density from vehicles in East China, enhanced vehicle, fuel and transportation strategies will be required to address vehicle emissions in China. We project the total vehicle population in China to reach 400-500 million by 2030. Serious air pollution problems in many cities of China, in particular high ambient PM 2.5 concentration, have led to pressure to accelerate the progress on vehicle emission reduction. A notable example is the draft China 6 emission standard released in May 2016, which contains more stringent emission limits than those in the Euro 6 regulations, and adds a real world emission testing protocol and a 48-h evaporation testing procedure including diurnal and hot soak emissions. A scenario (PC[1]) considered in this study suggests that increasingly stringent standards for vehicle emissions could mitigate total vehicle emissions of HC, CO, NO X and PM 2.5 in 2030 by approximately 39%, 57%, 59% and 79%, respectively, compared with 2013 levels. With additional actions

  14. 78 FR 20881 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ...The EPA is announcing two public hearings to be held for the proposed rule ``Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards'' (the proposed rule is hereinafter referred to as ``Tier 3''), which will be published separately in the Federal Register. The hearings will be held in Philadelphia, PA on April 24, 2013 and in Chicago, IL on April 29, 2013. The comment period for the proposed rulemaking will end on June 13, 2013.

  15. Control of xylem Na+ loading and transport to the shoot in rice and barley as a determinant of differential salinity stress tolerance.

    PubMed

    Ishikawa, Tetsuya; Shabala, Sergey

    2018-05-15

    Control of xylem Na + loading has often been named as the essential components of salinity tolerance mechanism. However, it is less clear to what extent the difference in this trait may determine differential salinity tolerance between species. In this study barley (Hordeum vulgare L. cv. CM72) and rice (Oryza sativa L. cv Dongjin) plants were grown under two levels of salinity. Na + and K + concentrations in the xylem sap, and shoot and root tissues were measured at different time points after stress onset. Salt-exposed rice plants prevented xylem Na + loading for several days, but failed to control this process in the longer term, ultimately resulting in a massive Na + shoot loading. Barley plants quickly increased xylem Na + concentration and its delivery to the shoot (most likely for the purpose of osmotic adjustment) but were able to reduce this process later on, keeping most of accumulated Na + in the root, thus maintaining non-toxic shoot Na + level. Rice plants increased shoot K + concentration, while barley plants maintained higher root K + concentration. Control of xylem Na + loading is remarkably different between rice and barley; this difference may differentiate the extent of the salinity tolerance between species. This trait should be investigated in more details to be used in the breeding programs aimed to improve salinity tolerance in crops. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. Vision-Based Leader Vehicle Trajectory Tracking for Multiple Agricultural Vehicles

    PubMed Central

    Zhang, Linhuan; Ahamed, Tofael; Zhang, Yan; Gao, Pengbo; Takigawa, Tomohiro

    2016-01-01

    The aim of this study was to design a navigation system composed of a human-controlled leader vehicle and a follower vehicle. The follower vehicle automatically tracks the leader vehicle. With such a system, a human driver can control two vehicles efficiently in agricultural operations. The tracking system was developed for the leader and the follower vehicle, and control of the follower was performed using a camera vision system. A stable and accurate monocular vision-based sensing system was designed, consisting of a camera and rectangular markers. Noise in the data acquisition was reduced by using the least-squares method. A feedback control algorithm was used to allow the follower vehicle to track the trajectory of the leader vehicle. A proportional–integral–derivative (PID) controller was introduced to maintain the required distance between the leader and the follower vehicle. Field experiments were conducted to evaluate the sensing and tracking performances of the leader-follower system while the leader vehicle was driven at an average speed of 0.3 m/s. In the case of linear trajectory tracking, the RMS errors were 6.5 cm, 8.9 cm and 16.4 cm for straight, turning and zigzag paths, respectively. Again, for parallel trajectory tracking, the root mean square (RMS) errors were found to be 7.1 cm, 14.6 cm and 14.0 cm for straight, turning and zigzag paths, respectively. The navigation performances indicated that the autonomous follower vehicle was able to follow the leader vehicle, and the tracking accuracy was found to be satisfactory. Therefore, the developed leader-follower system can be implemented for the harvesting of grains, using a combine as the leader and an unloader as the autonomous follower vehicle. PMID:27110793

  17. Vision-Based Leader Vehicle Trajectory Tracking for Multiple Agricultural Vehicles.

    PubMed

    Zhang, Linhuan; Ahamed, Tofael; Zhang, Yan; Gao, Pengbo; Takigawa, Tomohiro

    2016-04-22

    The aim of this study was to design a navigation system composed of a human-controlled leader vehicle and a follower vehicle. The follower vehicle automatically tracks the leader vehicle. With such a system, a human driver can control two vehicles efficiently in agricultural operations. The tracking system was developed for the leader and the follower vehicle, and control of the follower was performed using a camera vision system. A stable and accurate monocular vision-based sensing system was designed, consisting of a camera and rectangular markers. Noise in the data acquisition was reduced by using the least-squares method. A feedback control algorithm was used to allow the follower vehicle to track the trajectory of the leader vehicle. A proportional-integral-derivative (PID) controller was introduced to maintain the required distance between the leader and the follower vehicle. Field experiments were conducted to evaluate the sensing and tracking performances of the leader-follower system while the leader vehicle was driven at an average speed of 0.3 m/s. In the case of linear trajectory tracking, the RMS errors were 6.5 cm, 8.9 cm and 16.4 cm for straight, turning and zigzag paths, respectively. Again, for parallel trajectory tracking, the root mean square (RMS) errors were found to be 7.1 cm, 14.6 cm and 14.0 cm for straight, turning and zigzag paths, respectively. The navigation performances indicated that the autonomous follower vehicle was able to follow the leader vehicle, and the tracking accuracy was found to be satisfactory. Therefore, the developed leader-follower system can be implemented for the harvesting of grains, using a combine as the leader and an unloader as the autonomous follower vehicle.

  18. Umbilical vein injection of misoprostol versus normal saline for the treatment of retained placenta: intrapartum placebo-controlled trial.

    PubMed

    Rajab, Sheelan S; Alalaf, Shahla K

    2014-01-21

    The third stage of labour may be complicated by retained placenta, which should be managed promptly because it may cause severe bleeding and infection, with a potentially fatal outcome. This study evaluated the effectiveness of umbilical vein injection of misoprostol for the treatment of retained placenta in a hospital setting. This hospital-based placebo-controlled trial was conducted at the Maternity Teaching Hospital, Erbil City, Kurdistan region, Northern Iraq from April 2011 to February 2012. The inclusion criteria were: gestational age of at least 28 weeks, vaginal delivery, and failure of the placenta to separate within 30 minutes after delivery of the infant despite active management of the third stage of labour. Forty-six women with retained placentas were eligible for inclusion. After informed consent was obtained, the women were alternately allocated to receive umbilical vein injection of either 800 mcg misoprostol dissolved in 20 mL of normal saline (misoprostol group) or 20 mL of normal saline only (saline group). The women were blinded to the group allocation, but the investigator who administered the injection was not. The trial was registered by the Research Ethics Committee of Hawler Medical University. After umbilical vein injection, delivery of the placenta occurred in 91.3% of women in the misoprostol group and 69.5% of women in the saline group, which was not a significant difference between the two groups. The median vaginal blood loss from the time of injection until delivery of the placenta was significantly less in the misoprostol group (100 mL) than in the saline group (210 mL) (p value < 0.001). Umbilical vein injection of misoprostol is an effective treatment for retained placenta, and reduces the volume of vaginal blood loss with few adverse effects. Current Controlled Trial HMU: N252.1.2011.

  19. Umbilical vein injection of misoprostol versus normal saline for the treatment of retained placenta: intrapartum placebo-controlled trial

    PubMed Central

    2014-01-01

    Background The third stage of labour may be complicated by retained placenta, which should be managed promptly because it may cause severe bleeding and infection, with a potentially fatal outcome. This study evaluated the effectiveness of umbilical vein injection of misoprostol for the treatment of retained placenta in a hospital setting. Methods This hospital-based placebo-controlled trial was conducted at the Maternity Teaching Hospital, Erbil City, Kurdistan region, Northern Iraq from April 2011 to February 2012. The inclusion criteria were: gestational age of at least 28 weeks, vaginal delivery, and failure of the placenta to separate within 30 minutes after delivery of the infant despite active management of the third stage of labour. Forty-six women with retained placentas were eligible for inclusion. After informed consent was obtained, the women were alternately allocated to receive umbilical vein injection of either 800 mcg misoprostol dissolved in 20 mL of normal saline (misoprostol group) or 20 mL of normal saline only (saline group). The women were blinded to the group allocation, but the investigator who administered the injection was not. The trial was registered by the Research Ethics Committee of Hawler Medical University. Results After umbilical vein injection, delivery of the placenta occurred in 91.3% of women in the misoprostol group and 69.5% of women in the saline group, which was not a significant difference between the two groups. The median vaginal blood loss from the time of injection until delivery of the placenta was significantly less in the misoprostol group (100 mL) than in the saline group (210 mL) (p value < 0.001). Conclusion Umbilical vein injection of misoprostol is an effective treatment for retained placenta, and reduces the volume of vaginal blood loss with few adverse effects. Clinical Trial Registration Current Controlled Trial HMU: N252.1.2011 PMID:24444360

  20. The influence of vehicle aerodynamic and control response characteristics on driver-vehicle performance

    NASA Technical Reports Server (NTRS)

    Alexandridis, A. A.; Repa, B. S.; Wierwille, W. W.

    1978-01-01

    The effects of changes in understeer, control sensitivity, and location of the lateral aerodynamic center of pressure (c.p.) of a typical passenger car on the driver's opinion and on the performance of the driver-vehicle system were studied in a moving-base driving simulator. Twelve subjects with no prior experience on the simulator and no special driving skills performed regulation tasks in the presence of both random and step wind gusts.

  1. Charge control microcomputer device for vehicles

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Morishita, M.; Kouge, S.

    1986-10-14

    This patent describes a charge control microcomputer device for a vehicle, comprising: speed changing means for transmitting the output torque of an engine. The speed changing means includes a slip clutch means having an output with a variable slippage amount with respect to its input and controlled in accordance with an operating instruction. The speed changing means further includes a speed change gear for changing the rotational speed input thereto at an output thereto, the speed change gear receiving the output of the slip clutch means; a charging generator driven by the output of the speed change gear; a batterymore » charged by an output voltage of the charging generator; a voltage regulator for controlling the output voltage of the charging generator to a predetermined value; an engine controlling microcomputer for receiving data from the engine, to control the engine, the engine data comprising at least an engine speed signal; a charge control microcomputer for processing engine data from the engine controlling microcomputer and charge system data including terminal voltage data from the battery and generated voltage data from the changing generator; and a display unit for displaying detection data, including fault detection data, form the charge control microcomputer.« less

  2. Robust predictive cruise control for commercial vehicles

    NASA Astrophysics Data System (ADS)

    Junell, Jaime; Tumer, Kagan

    2013-10-01

    In this paper we explore learning-based predictive cruise control and the impact of this technology on increasing fuel efficiency for commercial trucks. Traditional cruise control is wasteful when maintaining a constant velocity over rolling hills. Predictive cruise control (PCC) is able to look ahead at future road conditions and solve for a cost-effective course of action. Model- based controllers have been implemented in this field but cannot accommodate many complexities of a dynamic environment which includes changing road and vehicle conditions. In this work, we focus on incorporating a learner into an already successful model- based predictive cruise controller in order to improve its performance. We explore back propagating neural networks to predict future errors then take actions to prevent said errors from occurring. The results show that this approach improves the model based PCC by up to 60% under certain conditions. In addition, we explore the benefits of classifier ensembles to further improve the gains due to intelligent cruise control.

  3. NASA Ares I Launch Vehicle Roll and Reaction Control Systems Lessons Learned

    NASA Technical Reports Server (NTRS)

    Butt, Adam; Popp, Chris G.; Jernigan, Frankie R.; Paseur, Lila F.; Pitts, Hank M.

    2011-01-01

    On April 15, 2010 President Barak Obama made the official announcement that the Constellation Program, which included the Ares I launch vehicle, would be canceled. NASA s Ares I launch vehicle was being designed to launch the Orion Crew Exploration Vehicle, returning humans to the moon, Mars, and beyond. It consisted of a First Stage (FS) five segment solid rocket booster and a liquid J-2X Upper Stage (US) engine. Roll control for the FS was planned to be handled by a dedicated Roll Control System (RoCS), located on the connecting interstage. Induced yaw or pitch moments experienced during FS ascent would have been handled by vectoring of the booster nozzle. After FS booster separation, the US Reaction Control System (ReCS) would have provided the US Element with three degrees of freedom control as needed. The lessons learned documented in this paper will be focused on the technical designs and producibility of both systems along with the partnership between NASA and Boeing, who was on contract to build the Ares I US Element, which included the FS RoCS and US ReCS. In regards to partnership, focus will be placed on integration along with technical work accomplished by Boeing with special emphasis on each task order. In summary, this paper attempts to capture key lessons learned that should be helpful in the development of future launch vehicle RCS designs.

  4. A Traction Control Strategy with an Efficiency Model in a Distributed Driving Electric Vehicle

    PubMed Central

    Lin, Cheng

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention. PMID:25197697

  5. A traction control strategy with an efficiency model in a distributed driving electric vehicle.

    PubMed

    Lin, Cheng; Cheng, Xingqun

    2014-01-01

    Both active safety and fuel economy are important issues for vehicles. This paper focuses on a traction control strategy with an efficiency model in a distributed driving electric vehicle. In emergency situation, a sliding mode control algorithm was employed to achieve antislip control through keeping the wheels' slip ratios below 20%. For general longitudinal driving cases, an efficiency model aiming at improving the fuel economy was built through an offline optimization stream within the two-dimensional design space composed of the acceleration pedal signal and the vehicle speed. The sliding mode control strategy for the joint roads and the efficiency model for the typical drive cycles were simulated. Simulation results show that the proposed driving control approach has the potential to apply to different road surfaces. It keeps the wheels' slip ratios within the stable zone and improves the fuel economy on the premise of tracking the driver's intention.

  6. Direct yaw moment control and power consumption of in-wheel motor vehicle in steady-state turning

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takao; Katsuyama, Etsuo; Sugiura, Hideki; Ono, Eiichi; Yamamoto, Masaki

    2017-01-01

    Driving force distribution control is one of the characteristic performance aspects of in-wheel motor vehicles and various methods have been developed to control direct yaw moment while turning. However, while these controls significantly enhance vehicle dynamic performance, the additional power required to control vehicle motion still remains to be clarified. This paper constructed new formulae of the mechanism by which direct yaw moment alters the cornering resistance and mechanical power of all wheels based on a simple bicycle model, including the electric loss of the motors and the inverters. These formulation results were validated by an actual test vehicle equipped with in-wheel motors in steady-state turning. The validated theory was also applied to a comparison of several different driving force distribution mechanisms from the standpoint of innate mechanical power.

  7. Hurricane-induced failure of low salinity wetlands

    PubMed Central

    Howes, Nick C.; FitzGerald, Duncan M.; Hughes, Zoe J.; Georgiou, Ioannis Y.; Kulp, Mark A.; Miner, Michael D.; Smith, Jane M.; Barras, John A.

    2010-01-01

    During the 2005 hurricane season, the storm surge and wave field associated with Hurricanes Katrina and Rita eroded 527 km2 of wetlands within the Louisiana coastal plain. Low salinity wetlands were preferentially eroded, while higher salinity wetlands remained robust and largely unchanged. Here we highlight geotechnical differences between the soil profiles of high and low salinity regimes, which are controlled by vegetation and result in differential erosion. In low salinity wetlands, a weak zone (shear strength 500–1450 Pa) was observed ∼30 cm below the marsh surface, coinciding with the base of rooting. High salinity wetlands had no such zone (shear strengths > 4500 Pa) and contained deeper rooting. Storm waves during Hurricane Katrina produced shear stresses between 425–3600 Pa, sufficient to cause widespread erosion of the low salinity wetlands. Vegetation in low salinity marshes is subject to shallower rooting and is susceptible to erosion during large magnitude storms; these conditions may be exacerbated by low inorganic sediment content and high nutrient inputs. The dramatic difference in resiliency of fresh versus more saline marshes suggests that the introduction of freshwater to marshes as part of restoration efforts may therefore weaken existing wetlands rendering them vulnerable to hurricanes. PMID:20660777

  8. Control of ethanol withdrawal symptoms in mice by phenytoin.

    PubMed

    Sprague, G L; Craigmill, A L

    1976-12-01

    Mice were made physically dependent upon ethanol using either of two methods which involved ethanol vapor inhalation. Following the cessation of exposure to ethanol, the severity of handling-induced convulsions and changes in the response to an electric foot shock (startle reflex) were recorded. Animals given isotonic saline or propylene glycol:ethanol vehicle during withdrawal exhibited handling-induced convulsions, and ethanol (2.0-4.0 g/kg) or phenytoin (5-20 mg/kg) administration during withdrawal resulted in a reduction in the severity of these convulsions. A reduced startle reflex threshold was also evident during withdrawal in mice given isotonic saline or propylene glycol:ethanol vehicle. Ethanol (0.5-4.0 g/kg) or phenytoin (10-20 mg/kg) administration during withdrawal resulted in a significant elevation of the startle reflex threshold compared to control animals. The results are discussed as they relate to others obtained in experimental and clinical studies.

  9. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

    NASA Technical Reports Server (NTRS)

    Gisser, D. G.; Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Yerazunis, S. Y.

    1975-01-01

    Problems related to an unmanned exploration of the planet Mars by means of an autonomous roving planetary vehicle are investigated. These problems include: design, construction and evaluation of the vehicle itself and its control and operating systems. More specifically, vehicle configuration, dynamics, control, propulsion, hazard detection systems, terrain sensing and modelling, obstacle detection concepts, path selection, decision-making systems, and chemical analyses of samples are studied. Emphasis is placed on development of a vehicle capable of gathering specimens and data for an Augmented Viking Mission or to provide the basis for a Sample Return Mission.

  10. Asymptotic sideslip angle and yaw rate decoupling control in four-wheel steering vehicles

    NASA Astrophysics Data System (ADS)

    Marino, Riccardo; Scalzi, Stefano

    2010-09-01

    This paper shows that, for a four-wheel steering vehicle, a proportional-integral (PI) active front steering control and a PI active rear steering control from the yaw rate error together with an additive feedforward reference signal for the vehicle sideslip angle can asymptotically decouple the lateral velocity and the yaw rate dynamics; that is the control can set arbitrary steady state values for lateral speed and yaw rate at any longitudinal speed. Moreover, the PI controls can suppress oscillatory behaviours by assigning real stable eigenvalues to a widely used linearised model of the vehicle steering dynamics for any value of longitudinal speed in understeering vehicles. In particular, the four PI control parameters are explicitly expressed in terms of the three real eigenvalues to be assigned. No lateral acceleration and no lateral speed measurements are required. The controlled system maintains the well-known advantages of both front and rear active steering controls: higher controllability, enlarged bandwidth for the yaw rate dynamics, suppressed resonances, new stable cornering manoeuvres and improved manoeuvrability. In particular, zero lateral speed may be asymptotically achieved while controlling the yaw rate: in this case comfort is improved since the phase lag between lateral acceleration and yaw rate is reduced. Also zero yaw rate can be asymptotically achieved: in this case additional stable manoeuvres are obtained in obstacle avoidance. Several simulations, including step references and moose tests, are carried out on a standard small SUV CarSim model to explore the robustness with respect to unmodelled effects such as combined lateral and longitudinal tyre forces, pitch, roll and driver dynamics. The simulations confirm the decoupling between the lateral velocity and the yaw rate and show the advantages obtained by the proposed control: reduced lateral speed or reduced yaw rate, suppressed oscillations and new stable manoeuvres.

  11. Protective Effects of Hydrogen-Rich Saline Against Lipopolysaccharide-Induced Alveolar Epithelial-to-Mesenchymal Transition and Pulmonary Fibrosis.

    PubMed

    Dong, Wen-Wen; Zhang, Yun-Qian; Zhu, Xiao-Yan; Mao, Yan-Fei; Sun, Xue-Jun; Liu, Yu-Jian; Jiang, Lai

    2017-05-19

    BACKGROUND Fibrotic change is one of the important reasons for the poor prognosis of patients with acute respiratory distress syndrome (ARDS). The present study investigated the effects of hydrogen-rich saline, a selective hydroxyl radical scavenger, on lipopolysaccharide (LPS)-induced pulmonary fibrosis. MATERIAL AND METHODS Male ICR mice were divided randomly into 5 groups: Control, LPS-treated plus vehicle treatment, and LPS-treated plus hydrogen-rich saline (2.5, 5, or 10 ml/kg) treatment. Twenty-eight days later, fibrosis was assessed by determination of collagen deposition, hydroxyproline, and type I collagen levels. Development of epithelial-to-mesenchymal transition (EMT) was identified by examining protein expressions of E-cadherin and α-smooth muscle actin (α-SMA). Transforming growth factor (TGF)-β1 content, total antioxidant capacity (T-AOC), malondialdehyde (MDA) content, catalase (CAT), and superoxide dismutase (SOD) activity were determined. RESULTS Mice exhibited increases in collagen deposition, hydroxyproline, type I collagen contents, and TGF-β1 production in lung tissues after LPS treatment. LPS-induced lung fibrosis was associated with increased expression of α-SMA, as well as decreased expression of E-cadherin. In addition, LPS treatment increased MDA levels but decreased T-AOC, CAT, and SOD activities in lung tissues, indicating that LPS induced pulmonary oxidative stress. Hydrogen-rich saline treatment at doses of 2.5, 5, or 10 ml/kg significantly attenuated LPS-induced pulmonary fibrosis. LPS-induced loss of E-cadherin in lung tissues was largely reversed, whereas the acquisition of α-SMA was dramatically decreased by hydrogen-rich saline treatment. In addition, hydrogen-rich saline treatment significantly attenuated LPS-induced oxidative stress. CONCLUSIONS Hydrogen-rich saline may protect against LPS-induced EMT and pulmonary fibrosis through suppressing oxidative stress.

  12. Control and design of multiple unmanned air vehicles for persistent surveillance

    NASA Astrophysics Data System (ADS)

    Nigam, Nikhil

    Control of multiple autonomous aircraft for search and exploration, is a topic of current research interest for applications such as weather monitoring, geographical surveys, search and rescue, tactical reconnaissance, and extra-terrestrial exploration, and the need to distribute sensing is driven by considerations of efficiency, reliability, cost and scalability. Hence, this problem has been extensively studied in the fields of controls and artificial intelligence. The task of persistent surveillance is different from a coverage/exploration problem, in that all areas need to be continuously searched, minimizing the time between visitations to each region in the target space. This distinction does not allow a straightforward application of most exploration techniques to the problem, although ideas from these methods can still be used. The use of aerial vehicles is motivated by their ability to cover larger spaces and their relative insensitivity to terrain. However, the dynamics of Unmanned Air Vehicles (UAVs) adds complexity to the control problem. Most of the work in the literature decouples the vehicle dynamics and control policies, but their interaction is particularly interesting for a surveillance mission. Stochastic environments and UAV failures further enrich the problem by requiring the control policies to be robust, and this aspect is particularly important for hardware implementations. For a persistent mission, it becomes imperative to consider the range/endurance constraints of the vehicles. The coupling of the control policy with the endurance constraints of the vehicles is an aspect that has not been sufficiently explored. Design of UAVs for desirable mission performance is also an issue of considerable significance. The use of a single monolithic optimization for such a problem has practical limitations, and decomposition-based design is a potential alternative. In this research high-level control policies are devised, that are scalable, reliable

  13. Formation control of VTOL UAV vehicles under switching-directed interaction topologies with disturbance rejection

    NASA Astrophysics Data System (ADS)

    Kabiri, Meisam; Atrianfar, Hajar; Menhaj, Mohammad B.

    2018-01-01

    This paper addresses the adaptive formation control of a group of vertical take-off and landing (VTOL) unmanned aerial vehicles (UAV) with switching-directed interaction topologies. In addition, to tackle the adverse effect of disturbances, a couple of smooth bounded estimators are involved in the procedure design. Exploiting an extraction algorithm, we take advantage of the fully actuated rotational dynamics, to control the translational dynamics of each vehicle. We propose a distributed control scheme such that all vehicles track a desired reference velocity signal while keeping a desired prespecified formation. In this framework, the underlying topology of the agents may switch among several directed graphs, each having a spanning tree. The stability of the overall closed-loop system is proved through Lyapunov function. Finally, simulation results are given to better highlight the effectiveness of the proposed control scheme.

  14. Robust stabilization control based on guardian maps theory for a longitudinal model of hypersonic vehicle.

    PubMed

    Liu, Yanbin; Liu, Mengying; Sun, Peihua

    2014-01-01

    A typical model of hypersonic vehicle has the complicated dynamics such as the unstable states, the nonminimum phases, and the strong coupling input-output relations. As a result, designing a robust stabilization controller is essential to implement the anticipated tasks. This paper presents a robust stabilization controller based on the guardian maps theory for hypersonic vehicle. First, the guardian maps theories are provided to explain the constraint relations between the open subsets of complex plane and the eigenvalues of the state matrix of closed-loop control system. Then, a general control structure in relation to the guardian maps theories is proposed to achieve the respected design demands. Furthermore, the robust stabilization control law depending on the given general control structure is designed for the longitudinal model of hypersonic vehicle. Finally, a simulation example is provided to verify the effectiveness of the proposed methods.

  15. Autonomous Reconfigurable Control Allocation (ARCA) for Reusable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Hodel, A. S.; Callahan, Ronnie; Jackson, Scott (Technical Monitor)

    2002-01-01

    The role of control allocation (CA) in modern aerospace vehicles is to compute a command vector delta(sub c) is a member of IR(sup n(sub a)) that corresponding to commanded or desired body-frame torques (moments) tou(sub c) = [L M N](sup T) to the vehicle, compensating for and/or responding to inaccuracies in off-line nominal control allocation calculations, actuator failures and/or degradations (reduced effectiveness), or actuator limitations (rate/position saturation). The command vector delta(sub c) may govern the behavior of, e.g., acrosurfaces, reaction thrusters, engine gimbals and/or thrust vectoring. Typically, the individual moments generated in response to each of the n(sub a) commands does not lie strictly in the roll, pitch, or yaw axes, and so a common practice is to group or gang actuators so that a one-to-one mapping from torque commands tau(sub c) actuator commands delta(sub c) may be achieved in an off-line computed CA function.

  16. Improving travel times for emergency response vehicles : traffic control strategies based on connected vehicles technologies : final report.

    DOT National Transportation Integrated Search

    2014-08-31

    This research is focused on developing and evaluating new traffic control strategies to enable emergency response vehicles (EVs) to travel in transportation networks as quickly as possible while the disruption to the rest of the traffic is kept to a ...

  17. A Feasibility Study on the Control of a Generic Air Vehicle Using Control Moment Gyros

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Moerder, Daniel D.

    2006-01-01

    This paper examines feasibility and performance issues in using Control Moment Gyroscopes (CMGs) to control the attitude of a fixed-wing aircraft. The paper describes a control system structure that permits allocating control authority and bandwidth between a CMG system and conventional aerodynamic control surfaces to stabilize a vehicle with neutral aerodynamic stability. A simulation study explores the interplay between aerodynamic and CMG effects, and indicates desirable physical characteristics for a CMG system to be used for aircraft attitude control.

  18. Development of agent-based on-line adaptive signal control (ASC) framework using connected vehicle (CV) technology.

    DOT National Transportation Integrated Search

    2016-04-01

    In this study, we developed an adaptive signal control (ASC) framework for connected vehicles (CVs) using agent-based modeling technique. : The proposed framework consists of two types of agents: 1) vehicle agents (VAs); and 2) signal controller agen...

  19. Direct and indirect controls on organic matter decomposition in four coastal wetland communities along a landscape salinity gradient

    USGS Publications Warehouse

    Stagg, Camille L.; Baustian, Melissa M.; Perry, Carey L.; Carruthers, Tim J.B.; Hall, Courtney T.

    2018-01-01

    Coastal wetlands store more carbon than most ecosystems globally. As sea level rises, changes in flooding and salinity will potentially impact ecological functions, such as organic matter decomposition, that influence carbon storage. However, little is known about the mechanisms that control organic matter loss in coastal wetlands at the landscape scale. As sea level rises, how will the shift from fresh to salt-tolerant plant communities impact organic matter decomposition? Do long-term, plant-mediated, effects of sea-level rise differ from direct effects of elevated salinity and flooding?We identified internal and external factors that regulated indirect and direct pathways of sea-level rise impacts, respectively, along a landscape-scale salinity gradient that incorporated changes in wetland type (fresh, oligohaline, mesohaline and polyhaline marshes). We found that indirect and direct impacts of sea-level rise had opposing effects on organic matter decomposition.Salinity had an indirect effect on litter decomposition that was mediated through litter quality. Despite significant variation in environmental conditions along the landscape gradient, the best predictors of above- and below-ground litter decomposition were internal drivers, initial litter nitrogen content and initial litter lignin content respectively. Litter decay constants were greatest in the oligohaline marsh and declined with increasing salinity, and the fraction of litter remaining (asymptote) was greatest in the mesohaline marsh. In contrast, direct effects of salinity and flooding were positive. External drivers, salinity and flooding, stimulated cellulytic activity, which was highest in the polyhaline marsh.Synthesis. Our results indicate that as sea level rises, initial direct effects of salinity will stimulate decay of labile carbon, but over time as plant communities shift from fresh to polyhaline marsh, litter decay will decline, yielding greater potential for long-term carbon storage

  20. Autonomous health management for PMSM rail vehicles through demagnetization monitoring and prognosis control.

    PubMed

    Niu, Gang; Jiang, Junjie; Youn, Byeng D; Pecht, Michael

    2018-01-01

    Autonomous vehicles are playing an increasingly importance in support of a wide variety of critical events. This paper presents a novel autonomous health management scheme on rail vehicles driven by permanent magnet synchronous motors (PMSMs). Firstly, the PMSMs are modeled based on first principle to deduce the initial profile of pneumatic braking (p-braking) force, then which is utilized for real-time demagnetization monitoring and degradation prognosis through similarity-based theory and generate prognosis-enhanced p-braking force strategy for final optimal control. A case study is conducted to demonstrate the feasibility and benefit of using the real-time prognostics and health management (PHM) information in vehicle 'drive-brake' control automatically. The results show that accurate demagnetization monitoring, degradation prognosis, and real-time capability for control optimization can be obtained, which can effectively relieve brake shoe wear. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  1. Resonant mode controllers for launch vehicle applications

    NASA Technical Reports Server (NTRS)

    Schreiner, Ken E.; Roth, Mary Ellen

    1992-01-01

    Electro-mechanical actuator (EMA) systems are currently being investigated for the National Launch System (NLS) as a replacement for hydraulic actuators due to the large amount of manpower and support hardware required to maintain the hydraulic systems. EMA systems in weight sensitive applications, such as launch vehicles, have been limited to around 5 hp due to system size, controller efficiency, thermal management, and battery size. Presented here are design and test data for an EMA system that competes favorably in weight and is superior in maintainability to the hydraulic system. An EMA system uses dc power provided by a high energy density bipolar lithium thionyl chloride battery, with power conversion performed by low loss resonant topologies, and a high efficiency induction motor controlled with a high performance field oriented controller to drive a linear actuator.

  2. Environmental Controls and Life Support System Design for a Space Exploration Vehicle

    NASA Technical Reports Server (NTRS)

    Stambaugh, Imelda C.; Rodriguez, Branelle; Vonau, Walt, Jr.; Borrego, Melissa

    2012-01-01

    Engineers at Johnson Space Center (JSC) are developing an Environmental Control and Life Support System (ECLSS) design for the Space Exploration Vehicle (SEV). The SEV will aid to expand the human exploration envelope for Geostationary Transfer Orbit (GEO), Near Earth Object (NEO), or planetary missions by using pressurized surface exploration vehicles. The SEV, formerly known as the Lunar Electric Rover (LER), will be an evolutionary design starting as a ground test prototype where technologies for various systems will be tested and evolve into a flight vehicle. This paper will discuss the current SEV ECLSS design, any work contributed toward the development of the ECLSS design, and the plan to advance the ECLSS design based on the SEV vehicle and system needs.

  3. Launch Vehicle Abort Analysis for Failures Leading to Loss of Control

    NASA Technical Reports Server (NTRS)

    Hanson, John M.; Hill, Ashley D.; Beard, Bernard B.

    2013-01-01

    Launch vehicle ascent is a time of high risk for an onboard crew. There is a large fraction of possible failures for which time is of the essence and a successful abort is possible if the detection and action happens quickly enough. This paper focuses on abort determination based on data already available from the Guidance, Navigation, and Control system. This work is the result of failure analysis efforts performed during the Ares I launch vehicle development program. The two primary areas of focus are the derivation of abort triggers to ensure that abort occurs as quickly as possible when needed, but that false aborts are avoided, and evaluation of success in aborting off the failing launch vehicle.

  4. NASA Ares I Launch Vehicle Roll and Reaction Control Systems Design Status

    NASA Technical Reports Server (NTRS)

    Butt, Adam; Popp, Chris G.; Pitts, Hank M.; Sharp, David J.

    2009-01-01

    This paper provides an update of design status following the preliminary design review of NASA s Ares I first stage roll and upper stage reaction control systems. The Ares I launch vehicle has been chosen to return humans to the moon, mars, and beyond. It consists of a first stage five segment solid rocket booster and an upper stage liquid bi-propellant J-2X engine. Similar to many launch vehicles, the Ares I has reaction control systems used to provide the vehicle with three degrees of freedom stabilization during the mission. During launch, the first stage roll control system will provide the Ares I with the ability to counteract induced roll torque. After first stage booster separation, the upper stage reaction control system will provide the upper stage element with three degrees of freedom control as needed. Trade studies and design assessments conducted on the roll and reaction control systems include: propellant selection, thruster arrangement, pressurization system configuration, and system component trades. Since successful completion of the preliminary design review, work has progressed towards the critical design review with accomplishments made in the following areas: pressurant / propellant tank, thruster assembly, and other component configurations, as well as thruster module design, and waterhammer mitigation approach. Also, results from early development testing are discussed along with plans for upcoming system testing. This paper concludes by summarizing the process of down selecting to the current baseline configuration for the Ares I roll and reaction control systems.

  5. Method and system for control of upstream flowfields of vehicle in supersonic or hypersonic atmospheric flight

    NASA Technical Reports Server (NTRS)

    Daso, Endwell O. (Inventor); Pritchett, II, Victor E. (Inventor); Wang, Ten-See (Inventor); Farr, Rebecca Ann (Inventor)

    2012-01-01

    The upstream flowfield of a vehicle traveling in supersonic or hypersonic atmospheric flight is actively controlled using attribute(s) experienced by the vehicle. Sensed attribute(s) include pressure along the vehicle's outer mold line, temperature along the vehicle's outer mold line, heat flux along the vehicle's outer mold line, and/or local acceleration response of the vehicle. A non-heated, non-plasma-producing gas is injected into an upstream flowfield of the vehicle from at least one surface location along the vehicle's outer mold line. The pressure of the gas so-injected is adjusted based on the attribute(s) so-sensed.

  6. Takeover Time in Highly Automated Vehicles: Noncritical Transitions to and From Manual Control.

    PubMed

    Eriksson, Alexander; Stanton, Neville A

    2017-06-01

    The aim of this study was to review existing research into driver control transitions and to determine the time it takes drivers to resume control from a highly automated vehicle in noncritical scenarios. Contemporary research has moved from an inclusive design approach to adhering only to mean/median values when designing control transitions in automated driving. Research into control transitions in highly automated driving has focused on urgent scenarios where drivers are given a relatively short time span to respond to a request to resume manual control. We found a paucity in research into more frequent scenarios for control transitions, such as planned exits from highway systems. Twenty-six drivers drove two scenarios with an automated driving feature activated. Drivers were asked to read a newspaper, or to monitor the system, and to relinquish, or resume, control from the automation when prompted by vehicle systems. Significantly longer control transition times were found between driving with and without secondary tasks. Control transition times were substantially longer than those reported in the peer-reviewed literature. We found that drivers take longer to resume control when under no time pressure compared with that reported in the literature. Moreover, we found that drivers occupied by a secondary task exhibit larger variance and slower responses to requests to resume control. Workload scores implied optimal workload. Intra- and interindividual differences need to be accommodated by vehicle manufacturers and policy makers alike to ensure inclusive design of contemporary systems and safety during control transitions.

  7. Efficient direct yaw moment control: tyre slip power loss minimisation for four-independent wheel drive vehicle

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takao; Katsuyama, Etsuo; Sugiura, Hideki; Ono, Eiichi; Yamamoto, Masaki

    2018-05-01

    This paper proposes an efficient direct yaw moment control (DYC) capable of minimising tyre slip power loss on contact patches for a four-independent wheel drive vehicle. Simulations identified a significant power loss reduction with a direct yaw moment due to a change in steer characteristics during acceleration or deceleration while turning. Simultaneously, the vehicle motion can be stabilised. As a result, the proposed control method can ensure compatibility between vehicle dynamics performance and energy efficiency. This paper also describes the results of a full-vehicle simulation that was conducted to examine the effectiveness of the proposed DYC.

  8. Final Rule for Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines; Non-Conformance Penalties for 2004 and later Model Year Emission Standards for Heavy-Duty Diesel Engines and Heavy-Duty Diesel Vehicles

    EPA Pesticide Factsheets

    Final Rule for Control of Air Pollution From New Motor Vehicles and New Motor Vehicle Engines; Non-Conformance Penalties for 2004 and later Model Year Emission Standards for Heavy-Duty Diesel Engines and Heavy-Duty Diesel Vehicles

  9. Robust Stabilization Control Based on Guardian Maps Theory for a Longitudinal Model of Hypersonic Vehicle

    PubMed Central

    Liu, Mengying; Sun, Peihua

    2014-01-01

    A typical model of hypersonic vehicle has the complicated dynamics such as the unstable states, the nonminimum phases, and the strong coupling input-output relations. As a result, designing a robust stabilization controller is essential to implement the anticipated tasks. This paper presents a robust stabilization controller based on the guardian maps theory for hypersonic vehicle. First, the guardian maps theories are provided to explain the constraint relations between the open subsets of complex plane and the eigenvalues of the state matrix of closed-loop control system. Then, a general control structure in relation to the guardian maps theories is proposed to achieve the respected design demands. Furthermore, the robust stabilization control law depending on the given general control structure is designed for the longitudinal model of hypersonic vehicle. Finally, a simulation example is provided to verify the effectiveness of the proposed methods. PMID:24795535

  10. Simulation of Liquid Injection Thrust Vector Control for Mars Ascent Vehicle

    NASA Technical Reports Server (NTRS)

    Gudenkauf, Jared

    2017-01-01

    The Jet Propulsion Laboratory is currently in the initial design phase for a potential Mars Ascent Vehicle; which will be landed on Mars, stay on the surface for period of time, collect samples from the Mars 2020 rover, and then lift these samples into orbit around Mars. The engineers at JPL have down selected to a hybrid wax-based fuel rocket using a liquid oxidizer based on nitrogen tetroxide, or a Mixed Oxide of Nitrogen. To lower the gross lift-off mass of the vehicle the thrust vector control system will use liquid injection of the oxidizer to deflect the thrust of the main nozzle instead of using a gimbaled nozzle. The disadvantage of going with the liquid injection system is the low technology readiness level with a hybrid rocket. Presented in this paper is an effort to simulate the Mars Ascent Vehicle hybrid rocket nozzle and liquid injection thrust vector control system using the computational fluid dynamic flow solver Loci/Chem. This effort also includes determining the sensitivity of the thrust vector control system to a number of different design variables for the injection ports; including axial location, number of adjacent ports, injection angle, and distance between the ports.

  11. Human vs autonomous control of planetary roving vehicles

    NASA Technical Reports Server (NTRS)

    Whitney, W. M.

    1974-01-01

    Supervisory or semiautonomous control has some compelling advantages over step-by-step human command and verification for the operation of roving vehicles on remote planetary surfaces. There are also disadvantages in relation to the complex system that must be mobilized and the chain of events that must be enacted to conduct a mission. Which of the two control methods is better on technical grounds may not be the deciding factor in its acceptance or rejection. Some of the issues that affect changes in spacecraft design and operation are summarized. To accelerate the movement toward more autonomous machines, it will be necessary to understand and to address the problems that such autonomy will create for other elements of the control system and for the control process.

  12. Modeling and control of a hybrid-electric vehicle for drivability and fuel economy improvements

    NASA Astrophysics Data System (ADS)

    Koprubasi, Kerem

    The gradual decline of oil reserves and the increasing demand for energy over the past decades has resulted in automotive manufacturers seeking alternative solutions to reduce the dependency on fossil-based fuels for transportation. A viable technology that enables significant improvements in the overall tank-to-wheel vehicle energy conversion efficiencies is the hybridization of electrical and conventional drive systems. Sophisticated hybrid powertrain configurations require careful coordination of the actuators and the onboard energy sources for optimum use of the energy saving benefits. The term optimality is often associated with fuel economy, although other measures such as drivability and exhaust emissions are also equally important. This dissertation focuses on the design of hybrid-electric vehicle (HEV) control strategies that aim to minimize fuel consumption while maintaining good vehicle drivability. In order to facilitate the design of controllers based on mathematical models of the HEV system, a dynamic model that is capable of predicting longitudinal vehicle responses in the low-to-mid frequency region (up to 10 Hz) is developed for a parallel HEV configuration. The model is validated using experimental data from various driving modes including electric only, engine only and hybrid. The high fidelity of the model makes it possible to accurately identify critical drivability issues such as time lags, shunt, shuffle, torque holes and hesitation. Using the information derived from the vehicle model, an energy management strategy is developed and implemented on a test vehicle. The resulting control strategy has a hybrid structure in the sense that the main mode of operation (the hybrid mode) is occasionally interrupted by event-based rules to enable the use of the engine start-stop function. The changes in the driveline dynamics during this transition further contribute to the hybrid nature of the system. To address the unique characteristics of the HEV

  13. A Discussion of Aerodynamic Control Effectors (ACEs) for Unmanned Air Vehicles (UAVs)

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.

    2002-01-01

    A Reynolds number based, unmanned air vehicle classification structure has been developed which identifies four classes of unmanned air vehicle concepts. The four unmanned air vehicle (UAV) classes are; Micro UAV, Meso UAV, Macro UAV, and Mega UAV. In a similar fashion a labeling scheme for aerodynamic control effectors (ACE) was developed and eleven types of ACE concepts were identified. These eleven types of ACEs were laid out in a five (5) layer scheme. The final section of the paper correlated the various ACE concepts to the four UAV classes and ACE recommendations are offered for future design activities.

  14. Static stability and control effectiveness of a parametric launch vehicle

    NASA Technical Reports Server (NTRS)

    Ellis, R. R.; Gamble, M.

    1972-01-01

    An investigation is reported to determine the static aerodynamic characteristics of a space shuttle parametric launch configuration. The orbiter control surfaces were deflected to obtain the control effectiveness for use in launch vehicle control studies. Experimental data were obtained for Mach number from 0.6 to 4.96, angles of attack from minus 10 to plus 10 degrees and angles of sideslip from minus six to six degrees at zero degrees angle of attack.

  15. Simulation and analysis of vertical displacement characteristics of three wheels reverse trike vehicle with PID controller application

    NASA Astrophysics Data System (ADS)

    Wibowo, Lambang, Lullus; Erick Chandra, N.; Muhayat, Nurul; Jaka S., B.

    2017-08-01

    The purpose of this research is to obtain a mathematical model (Full Vehicle Model) and compare the performance of passive and active suspension systems of a Three-Wheels Reverse Trike vehicle. Vehicle suspension system should able to provide good steering handling and passenger comfort. Vehicle suspension system generally only uses passive suspension components with fix spring and damper coefficients. An active suspension developed from the traditional (passive) suspension design can directly control the actuator force in the suspension system. In this paper, modeling and simulation of passive and active suspension system for a Full Vehicle Model is performed using Simulink-MATLAB software. Ziegler & Nichols tuning method is used to obtain controller parameters of Proportional Integral Derivative (PID) controller. Comparison between passive and active suspension with PID controller is conducted for disturbances input of single bump road surface profile 0.1 meters. The results are the displacement and acceleration of the vehicle body in the vertical direction of active suspension system with PID control is better in providing handling capabilities and comfort for the driver than of passive suspension system. The acceleration of 1,8G with the down time of 2.5 seconds is smaller than the acceleration of 2.5G with down time of 5.5 seconds.

  16. 40 CFR 80.500 - What are the implementation dates for the motor vehicle diesel fuel sulfur control program?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... the motor vehicle diesel fuel sulfur control program? 80.500 Section 80.500 Protection of Environment... Motor Vehicle Diesel Fuel; Nonroad, Locomotive, and Marine Diesel Fuel; and ECA Marine Fuel General Information § 80.500 What are the implementation dates for the motor vehicle diesel fuel sulfur control...

  17. 40 CFR 80.500 - What are the implementation dates for the motor vehicle diesel fuel sulfur control program?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the motor vehicle diesel fuel sulfur control program? 80.500 Section 80.500 Protection of Environment... Motor Vehicle Diesel Fuel; Nonroad, Locomotive, and Marine Diesel Fuel; and ECA Marine Fuel General Information § 80.500 What are the implementation dates for the motor vehicle diesel fuel sulfur control...

  18. The Efficacy of Calcium Hydroxide Powder mixed with 0.2% Chlorhexidine Digluconate or mixed with Normal Saline as Intracanal Medicament in the Treatment of Apical Periodontitis.

    PubMed

    Menakaya, Ifeoma N; Adegbulugbe, Ilemobade C; Oderinu, Olabisi H; Shaba, Olufemi P

    2015-08-01

    To compare the efficacy of calcium hydroxide powder mixed with 0.2% chlorhexidine digluconate or mixed with normal saline as intracanal medicament in the treatment of apical periodontitis. Subjects were 55 in number aged 17 to 60 years. Two-visit conventional root canal treatment was performed on 70 teeth. The teeth were divided by randomization (balloting) into two groups: control group and experimental group, each with 35 teeth treated with calcium hydroxide mixed with normal saline or with 0.2% chlorhexidine digluconate as intracanal medicament respectively. All treated teeth were evaluated clinically and radiographically for signs and symptom of periapical infection at specified periods postoperatively. Overall efficacy of medicament was rated based on quality guidelines for endodontic treatment by the European Society of Endodontology 2006. A postoperative favorable outcome of 97.1% in the control group and 94.3% in the experimental group was observed at 6-month review. This difference was not statistically significant (p > 0.05). The use of normal saline or 0.2% chlorhexidine digluconate to mix calcium hydroxide used as intracanal medicament during endodontic treatment resulted in high postoperative favorable outcomes. Efficacy of 0.2% chlorhexidine digluconate as a vehicle for mixing calcium hydroxide as an intracanal medicament in the treatment of apical periodontitis is comparable to the efficacy of calcium hydroxide mixed with normal saline.

  19. Zeta potential in oil-brine-sandstone system and its role in oil recovery during controlled salinity waterflooding

    NASA Astrophysics Data System (ADS)

    Li, S.; Jackson, M.

    2017-12-01

    Wettability alteration is widely recognised as a primary role in improved oil recovery (IOR) during controlled salinity waterflooding (CSW) by modifying brine composition. The change of wettability of core sample depends on adsorption of polar oil compounds into the mineral surface which influences its surface charge density and zeta potential. It has been proved that zeta potentials can be useful to quantify the wettability and incremental oil recovery in natural carbonates. However, the study of zeta potential in oil-brine-sandstone system has not investigated yet. In this experimental study, the zeta potential is used to examine the controlled salinity effects on IOR in nature sandstone (Doddington) aged with two types of crude oils (Oil T and Oil D) over 4 weeks at 80 °C. Results show that the zeta potential measured in the Oil T-brine-sandstone system following primary waterflooding decreases compared to that in fully water saturation, which is consistent with the negative oil found in carbonates study, and IOR response during secondary waterflooding using diluted seawater was observed. In the case of negative oil, the injected low salinity brine induces a more repulsive electrostatic force between the mineral-brine interface and oil-brine interface, which results in an increase disjoining pressure and alters the rock surface to be more water-wet. For Oil D with a positive oil-brine interface, the zeta potential becomes more positive compared to that under single phase condition. The conventional waterflooding fails to observe the IOR in Oil D-brine-sandstone system due to a less repulsive electrostatic force built up between the two interfaces. After switching the injection brine from low salinity brine to formation brine, the IOR was observed. Measured zeta potentials shed some light on the mechanism of wettability alteration in the oil-brine-sandstone system and oil recovery during CSW.

  20. Saline in acute bronchiolitis RCT and economic evaluation: hypertonic saline in acute bronchiolitis - randomised controlled trial and systematic review.

    PubMed

    Everard, Mark L; Hind, Daniel; Ugonna, Kelechi; Freeman, Jennifer; Bradburn, Mike; Dixon, Simon; Maguire, Chin; Cantrill, Hannah; Alexander, John; Lenney, Warren; McNamara, Paul; Elphick, Heather; Chetcuti, Philip Aj; Moya, Eduardo F; Powell, Colin; Garside, Jonathan P; Chadha, Lavleen Kumar; Kurian, Matthew; Lehal, Ravinderjit S; MacFarlane, Peter I; Cooper, Cindy L; Cross, Elizabeth

    2015-08-01

    Acute bronchiolitis is the most common cause of hospitalisation in infancy. Supportive care and oxygen are the cornerstones of management. A Cochrane review concluded that the use of nebulised 3% hypertonic saline (HS) may significantly reduce the duration of hospitalisation. To test the hypothesis that HS reduces the time to when infants were assessed as being fit for discharge, defined as in air with saturations of > 92% for 6 hours, by 25%. Parallel-group, pragmatic randomised controlled trial, cost-utility analysis and systematic review. Ten UK hospitals. Infants with acute bronchiolitis requiring oxygen therapy were allocated within 4 hours of admission. Supportive care with oxygen as required, minimal handling and fluid administration as appropriate to the severity of the disease, 3% nebulised HS every ± 6 hours. The trial primary outcome was time until the infant met objective discharge criteria. Secondary end points included time to discharge and adverse events. The costs analysed related to length of stay (LoS), readmissions, nebulised saline and other NHS resource use. Quality-adjusted life-years (QALYs) were estimated using an existing utility decrement derived for hospitalisation in children, together with the time spent in hospital in the trial. We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and other databases from inception or from 2010 onwards, searched ClinicalTrials.gov and other registries and hand-searched Chest, Paediatrics and Journal of Paediatrics to January 2015. We included randomised/quasi-randomised trials which compared HS versus saline (± adjunct treatment) or no treatment. We used a fixed-effects model to combine mean differences for LoS and assessed statistical heterogeneity using the I (2) statistic. The trial randomised 158 infants to HS (n = 141 analysed) and 159 to standard care (n = 149 analysed). There was no difference between the two arms in the time to being declared fit for

  1. Method and apparatus for controlling battery charging in a hybrid electric vehicle

    DOEpatents

    Phillips, Anthony Mark; Blankenship, John Richard; Bailey, Kathleen Ellen; Jankovic, Miroslava

    2003-06-24

    A starter/alternator system (24) for hybrid electric vehicle (10) having an internal combustion engine (12) and an energy storage device (34) has a controller (30) coupled to the starter/alternator (26). The controller (30) has a state of charge manager (40) that monitors the state of charge of the energy storage device. The controller has eight battery state-of-charge threshold values that determine the hybrid operating mode of the hybrid electric vehicle. The value of the battery state-of-charge relative to the threshold values is a factor in the determination of the hybrid mode, for example; regenerative braking, charging, battery bleed, boost. The starter/alternator may be operated as a generator or a motor, depending upon the mode.

  2. An empirical study of the effectiveness of electronic stability control system in reducing loss of vehicle control.

    PubMed

    Papelis, Yiannis E; Watson, Ginger S; Brown, Timothy L

    2010-05-01

    A significant percentage of fatal vehicle crashes involve loss of control (LOC). Electronic stability control (ESC) is an active safety system that detects impending LOC and activates counter-measures that help the driver maintain or re-gain control. To assess the effectiveness of ESC in preventing LOC, an empirical study was conducted on a high-fidelity driving simulator. The ESC systems for two vehicles were incorporated into the simulator's dynamics code which was calibrated to ensure engineering validation. The study utilized three scenarios designed to recreate typical LOC situations, and was designed to assess the effects of ESC presence, vehicle type, scenario, age and gender. A total of 120 research participants completed the study. Results showed a statistically significant reduction in LOC with ESC compared to without ESC (F=52.72, p<0.0001). The study findings of 5% LOC with ESC and 30% without ESC match several epidemiological studies that have analyzed ESC effectiveness on real-world crashes, providing strong support to the use of driving simulation for studying driver behavior. Study conclusions suggest that wide-spread utilization of ESC is likely to reduce traffic fatalities. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  3. Fuzzy Traffic Control with Vehicle-to-Everything Communication.

    PubMed

    Salman, Muntaser A; Ozdemir, Suat; Celebi, Fatih V

    2018-01-27

    Traffic signal control (TSC) with vehicle-to everything (V2X) communication can be a very efficient solution to traffic congestion problem. Ratio of vehicles equipped with V2X communication capability in the traffic to the total number of vehicles (called penetration rate PR) is still low, thus V2X based TSC systems need to be supported by some other mechanisms. PR is the major factor that affects the quality of TSC process along with the evaluation interval. Quality of the TSC in each direction is a function of overall TSC quality of an intersection. Hence, quality evaluation of each direction should follow the evaluation of the overall intersection. Computational intelligence, more specifically swarm algorithm, has been recently used in this field in a European Framework Program FP7 supported project called COLOMBO. In this paper, using COLOMBO framework, further investigations have been done and two new methodologies using simple and fuzzy logic have been proposed. To evaluate the performance of our proposed methods, a comparison with COLOMBOs approach has been realized. The results reveal that TSC problem can be solved as a logical problem rather than an optimization problem. Performance of the proposed approaches is good enough to be suggested for future work under realistic scenarios even under low PR.

  4. Fuzzy Traffic Control with Vehicle-to-Everything Communication

    PubMed Central

    Ozdemir, Suat; Celebi, Fatih V.

    2018-01-01

    Traffic signal control (TSC) with vehicle-to everything (V2X) communication can be a very efficient solution to traffic congestion problem. Ratio of vehicles equipped with V2X communication capability in the traffic to the total number of vehicles (called penetration rate PR) is still low, thus V2X based TSC systems need to be supported by some other mechanisms. PR is the major factor that affects the quality of TSC process along with the evaluation interval. Quality of the TSC in each direction is a function of overall TSC quality of an intersection. Hence, quality evaluation of each direction should follow the evaluation of the overall intersection. Computational intelligence, more specifically swarm algorithm, has been recently used in this field in a European Framework Program FP7 supported project called COLOMBO. In this paper, using COLOMBO framework, further investigations have been done and two new methodologies using simple and fuzzy logic have been proposed. To evaluate the performance of our proposed methods, a comparison with COLOMBOs approach has been realized. The results reveal that TSC problem can be solved as a logical problem rather than an optimization problem. Performance of the proposed approaches is good enough to be suggested for future work under realistic scenarios even under low PR. PMID:29382053

  5. Optimal Predictive Control for Path Following of a Full Drive-by-Wire Vehicle at Varying Speeds

    NASA Astrophysics Data System (ADS)

    SONG, Pan; GAO, Bolin; XIE, Shugang; FANG, Rui

    2017-05-01

    The current research of the global chassis control problem for the full drive-by-wire vehicle focuses on the control allocation (CA) of the four-wheel-distributed traction/braking/steering systems. However, the path following performance and the handling stability of the vehicle can be enhanced a step further by automatically adjusting the vehicle speed to the optimal value. The optimal solution for the combined longitudinal and lateral motion control (MC) problem is given. First, a new variable step-size spatial transformation method is proposed and utilized in the prediction model to derive the dynamics of the vehicle with respect to the road, such that the tracking errors can be explicitly obtained over the prediction horizon at varying speeds. Second, a nonlinear model predictive control (NMPC) algorithm is introduced to handle the nonlinear coupling between any two directions of the vehicular planar motion and computes the sequence of the optimal motion states for following the desired path. Third, a hierarchical control structure is proposed to separate the motion controller into a NMPC based path planner and a terminal sliding mode control (TSMC) based path follower. As revealed through off-line simulations, the hierarchical methodology brings nearly 1700% improvement in computational efficiency without loss of control performance. Finally, the control algorithm is verified through a hardware in-the-loop simulation system. Double-lane-change (DLC) test results show that by using the optimal predictive controller, the root-mean-square (RMS) values of the lateral deviations and the orientation errors can be reduced by 41% and 30%, respectively, comparing to those by the optimal preview acceleration (OPA) driver model with the non-preview speed-tracking method. Additionally, the average vehicle speed is increased by 0.26 km/h with the peak sideslip angle suppressed to 1.9°. This research proposes a novel motion controller, which provides the full drive

  6. Dynamics control of autonomous vehicle at driving limits and experiment on an autonomous formula racing car

    NASA Astrophysics Data System (ADS)

    Ni, Jun; Hu, Jibin

    2017-06-01

    In this paper, a novel dynamics controller for autonomous vehicle to simultaneously control it to the driving limits and follow the desired path is proposed. The dynamics controller consists of longitudinal and lateral controllers. In longitudinal controller, the G-G diagram is utilized to describe the driving and handling limits of the vehicle. The accurate G-G diagram is obtained based on phase plane approach and a nonlinear vehicle dynamic model with accurate tyre model. In lateral controller, the tyre cornering stiffness is estimated to improve the robustness of the controller. The stability analysis of the closed-looped error dynamics shows that the controller remains stable against parameters uncertainties in extreme condition such as tyre saturation. Finally, an electric autonomous Formula race car developed by the authors is used to validate the proposed controller. The autonomous driving experiment on an oval race track shows the efficiency and robustness of the proposed controller.

  7. Electric and hybrid vehicles environmental control subsystem study

    NASA Technical Reports Server (NTRS)

    1981-01-01

    An environmental control subsystem (ECS) in the passenger compartment of electric and hybrid vehicles is studied. Various methods of obtaining the desired temperature control for the battery pack is also studied. The functional requirements of ECS equipment is defined. Following categorization by methodology, technology availability and risk, all viable ECS concepts are evaluated. Each is assessed independently for benefits versus risk, as well as for its feasibility to short, intermediate and long term product development. Selection of the preferred concept is made against these requirements, as well as the study's major goal of providing safe, highly efficient and thermally confortable ECS equipment.

  8. Design of a data-driven predictive controller for start-up process of AMT vehicles.

    PubMed

    Lu, Xiaohui; Chen, Hong; Wang, Ping; Gao, Bingzhao

    2011-12-01

    In this paper, a data-driven predictive controller is designed for the start-up process of vehicles with automated manual transmissions (AMTs). It is obtained directly from the input-output data of a driveline simulation model constructed by the commercial software AMESim. In order to obtain offset-free control for the reference input, the predictor equation is gained with incremental inputs and outputs. Because of the physical characteristics, the input and output constraints are considered explicitly in the problem formulation. The contradictory requirements of less friction losses and less driveline shock are included in the objective function. The designed controller is tested under nominal conditions and changed conditions. The simulation results show that, during the start-up process, the AMT clutch with the proposed controller works very well, and the process meets the control objectives: fast clutch lockup time, small friction losses, and the preservation of driver comfort, i.e., smooth acceleration of the vehicle. At the same time, the closed-loop system has the ability to reject uncertainties, such as the vehicle mass and road grade.

  9. Simulink-Based Simulation Architecture for Evaluating Controls for Aerospace Vehicles (SAREC-ASV)

    NASA Technical Reports Server (NTRS)

    Christhilf, David m.; Bacon, Barton J.

    2006-01-01

    The Simulation Architecture for Evaluating Controls for Aerospace Vehicles (SAREC-ASV) is a Simulink-based approach to providing an engineering quality desktop simulation capability for finding trim solutions, extracting linear models for vehicle analysis and control law development, and generating open-loop and closed-loop time history responses for control system evaluation. It represents a useful level of maturity rather than a finished product. The layout is hierarchical and supports concurrent component development and validation, with support from the Concurrent Versions System (CVS) software management tool. Real Time Workshop (RTW) is used to generate pre-compiled code for substantial component modules, and templates permit switching seamlessly between original Simulink and code compiled for various platforms. Two previous limitations are addressed. Turn around time for incorporating tabular model components was improved through auto-generation of required Simulink diagrams based on data received in XML format. The layout was modified to exploit a Simulink "compile once, evaluate multiple times" capability for zero elapsed time for use in trimming and linearizing. Trim is achieved through a Graphical User Interface (GUI) with a narrow, script definable interface to the vehicle model which facilitates incorporating new models.

  10. Detecting Approaching Vehicles at Streets with No Traffic Control

    ERIC Educational Resources Information Center

    Emerson, Robert Wall; Sauerburger, Dona

    2008-01-01

    This study assessed the ability of people with visual impairments to reliably detect oncoming traffic at crossing situations with no traffic control. In at least one condition, the participants could not hear vehicles to afford a safe crossing time when sound levels were as quiet as possible. Significant predictors of detection accounted for a…

  11. Synthesis of the unmanned aerial vehicle remote control augmentation system

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tomczyk, Andrzej, E-mail: A.Tomczyk@prz.edu.pl

    Medium size Unmanned Aerial Vehicle (UAV) usually flies as an autonomous aircraft including automatic take-off and landing phases. However in the case of the on-board control system failure, the remote steering is using as an emergency procedure. In this reason, remote manual control of unmanned aerial vehicle is used more often during take-of and landing phases. Depends on UAV take-off mass and speed (total energy) the potential crash can be very danger for airplane and environment. So, handling qualities of UAV is important from pilot-operator point of view. In many cases the dynamic properties of remote controlling UAV are notmore » suitable for obtaining the desired properties of the handling qualities. In this case the control augmentation system (CAS) should be applied. Because the potential failure of the on-board control system, the better solution is that the CAS algorithms are placed on the ground station computers. The method of UAV handling qualities shaping in the case of basic control system failure is presented in this paper. The main idea of this method is that UAV reaction on the operator steering signals should be similar - almost the same - as reaction of the 'ideal' remote control aircraft. The model following method was used for controller parameters calculations. The numerical example concerns the medium size MP-02A UAV applied as an aerial observer system.« less

  12. Characterization of in-use light-duty gasoline vehicle emissions by remote sensing in Beijing: impact of recent control measures.

    PubMed

    Zhou, Yu; Fu, Lixin; Cheng, Linglin

    2007-09-01

    China's national government and Beijing city authorities have adopted additional control measures to reduce the negative impact of vehicle emissions on Beijing's air quality. An evaluation of the effectiveness of these measures may provide guidance for future vehicle emission control strategy development. In-use emissions from light-duty gasoline vehicles (LDGVs) were investigated at five sites in Beijing with remote sensing instrumentation. Distance-based mass emission factors were derived with fuel consumption modeled on real world data. The results show that the recently implemented aggressive control strategies are significantly reducing the emissions of on-road vehicles. Older vehicles are contributing substantially to the total fleet emissions. An earlier program to retrofit pre-Euro cars with three-way catalysts produced little emission reduction. The impact of model year and driving conditions on the average mass emission factors indicates that the durability of vehicles emission controls may be inadequate in Beijing.

  13. Conversion and control of an all-terrain vehicle for use as an autonomous mobile robot

    NASA Astrophysics Data System (ADS)

    Jacob, John S.; Gunderson, Robert W.; Fullmer, R. R.

    1998-08-01

    A systematic approach to ground vehicle automation is presented, combining low-level controls, trajectory generation and closed-loop path correction in an integrated system. Development of cooperative robotics for precision agriculture at Utah State University required the automation of a full-scale motorized vehicle. The Triton Predator 8- wheeled skid-steering all-terrain vehicle was selected for the project based on its ability to maneuver precisely and the simplicity of controlling the hydrostatic drivetrain. Low-level control was achieved by fitting an actuator on the engine throttle, actuators for the left and right drive controls, encoders on the left and right drive shafts to measure wheel speeds, and a signal pick-off on the alternator for measuring engine speed. Closed loop control maintains a desired engine speed and tracks left and right wheel speeds commands. A trajectory generator produces the wheel speed commands needed to steer the vehicle through a predetermined set of map coordinates. A planar trajectory through the points is computed by fitting a 2D cubic spline over each path segment while enforcing initial and final orientation constraints at segment endpoints. Acceleration and velocity profiles are computed for each trajectory segment, with the velocity over each segment dependent on turning radius. Left and right wheel speed setpoints are obtained by combining velocity and path curvature for each low-level timestep. The path correction algorithm uses GPS position and compass orientation information to adjust the wheel speed setpoints according to the 'crosstrack' and 'downtrack' errors and heading error. Nonlinear models of the engine and the skid-steering vehicle/ground interaction were developed for testing the integrated system in simulation. These test lead to several key design improvements which assisted final implementation on the vehicle.

  14. Mechanisms Controlling Variability of Lake Salinity in Dune Environments in a Semi-arid Climate: The Nebraska Sand Hills (Invited)

    NASA Astrophysics Data System (ADS)

    Zlotnik, V. A.; Ong, J. T.; Swinehart, J. B.; Fritz, S. C.; Lenters, J. D.; Schmieder, J. U.; Lane, J. W.; Halihan, T.

    2010-12-01

    Shallow endorheic saline lakes are common in semi-arid environments in North America, Africa, Asia, and Australia. These lakes receive minimal surface runoff and are supported by groundwater seepage. A combination of hydrologic and geologic factors (regional groundwater flow, evaporation, precipitation, lake size, groundwater recharge, and geologic setting) may preclude seepage out of these lakes, even in the presence of ambient regional flow. Solutes from groundwater are captured by these lakes and become enriched over time by evaporation. The importance of understanding lake dynamics in these arid and semi-arid systems is increasing with societal concerns, including water availability and quality, the use of aquatic ecosystems by waterfowl and other biota, and dangers of dust emissions associated with lake desiccation. We consider the salinity of shallow lakes as a useful indicator of hydroclimatic factors operating at centennial and millennial scales. The Nebraska Sand Hills cover 58 000 km2 of the central Great Plains and are the largest dunefield in the Western Hemisphere. The grass-stabilized dunes attain heights up to 130 m and have been modified by soil development and erosion. In an area <7000 km2, there are ~400 lakes with surface areas >4 ha and depths <1 m. Annual lake evaporation exceeds precipitation by 600 mm, according to some estimates. The salinity of natural lakes in the Nebraska Sand Hills ranges from fresh (~0.3 g L-1) to hypersaline (>100 g L-1), with pH values as high as ~10. We assess the mechanisms that control lake salinity in a group of lakes with different subsurface flow regimes. Our methods combine aquifer coring, electromagnetic and electrical resistivity tomography geophysics, hydraulic testing, lakebed dating using 14C and optically stimulated luminescence, energy and water balance analysis, and salt crust and dust collection. Our theory and results show that terrain and water-table topography, lithology, and climate control the

  15. Master-slave control scheme in electric vehicle smart charging infrastructure.

    PubMed

    Chung, Ching-Yen; Chynoweth, Joshua; Chu, Chi-Cheng; Gadh, Rajit

    2014-01-01

    WINSmartEV is a software based plug-in electric vehicle (PEV) monitoring, control, and management system. It not only incorporates intelligence at every level so that charge scheduling can avoid grid bottlenecks, but it also multiplies the number of PEVs that can be plugged into a single circuit. This paper proposes, designs, and executes many upgrades to WINSmartEV. These upgrades include new hardware that makes the level 1 and level 2 chargers faster, more robust, and more scalable. It includes algorithms that provide a more optimal charge scheduling for the level 2 (EVSE) and an enhanced vehicle monitoring/identification module (VMM) system that can automatically identify PEVs and authorize charging.

  16. Energy control strategy for a hybrid electric vehicle

    DOEpatents

    Phillips, Anthony Mark; Blankenship, John Richard; Bailey, Kathleen Ellen; Jankovic, Miroslava

    2002-08-27

    An energy control strategy (10) for a hybrid electric vehicle that controls an electric motor during bleed and charge modes of operation. The control strategy (10) establishes (12) a value of the power level at which the battery is to be charged. The power level is used to calculate (14) the torque to be commanded to the electric motor. The strategy (10) of the present invention identifies a transition region (22) for the electric motor's operation that is bounded by upper and lower speed limits. According to the present invention, the desired torque is calculated by applying equations to the regions before, during and after the transition region (22), the equations being a function of the power level and the predetermined limits and boundaries.

  17. Energy control strategy for a hybrid electric vehicle

    DOEpatents

    Phillips, Anthony Mark; Blankenship, John Richard; Bailey, Kathleen Ellen; Jankovic, Miroslava

    2002-01-01

    An energy control strategy (10) for a hybrid electric vehicle that controls an electric motor during bleed and charge modes of operation. The control strategy (10) establishes (12) a value of the power level at which the battery is to be charged. The power level is used to calculate (14) the torque to be commanded to the electric motor. The strategy (10) of the present invention identifies a transition region (22) for the electric motor's operation that is bounded by upper and lower speed limits. According to the present invention, the desired torque is calculated by applying equations to the regions before, during and after the transition region (22), the equations being a function of the power level and the predetermined limits and boundaries.

  18. Fuzzy chaos control for vehicle lateral dynamics based on active suspension system

    NASA Astrophysics Data System (ADS)

    Huang, Chen; Chen, Long; Jiang, Haobin; Yuan, Chaochun; Xia, Tian

    2014-07-01

    The existing research of the active suspension system (ASS) mainly focuses on the different evaluation indexes and control strategies. Among the different components, the nonlinear characteristics of practical systems and control are usually not considered for vehicle lateral dynamics. But the vehicle model has some shortages on tyre model with side-slip angle, road adhesion coefficient, vertical load and velocity. In this paper, the nonlinear dynamic model of lateral system is considered and also the adaptive neural network of tire is introduced. By nonlinear analysis methods, such as the bifurcation diagram and Lyapunov exponent, it has shown that the lateral dynamics exhibits complicated motions with the forward speed. Then, a fuzzy control method is applied to the lateral system aiming to convert chaos into periodic motion using the linear-state feedback of an available lateral force with changing tire load. Finally, the rapid control prototyping is built to conduct the real vehicle test. By comparison of time response diagram, phase portraits and Lyapunov exponents at different work conditions, the results on step input and S-shaped road indicate that the slip angle and yaw velocity of lateral dynamics enter into stable domain and the results of test are consistent to the simulation and verified the correctness of simulation. And the Lyapunov exponents of the closed-loop system are becoming from positive to negative. This research proposes a fuzzy control method which has sufficient suppress chaotic motions as an effective active suspension system.

  19. A robust H∞ control-based hierarchical mode transition control system for plug-in hybrid electric vehicle

    NASA Astrophysics Data System (ADS)

    Yang, Chao; Jiao, Xiaohong; Li, Liang; Zhang, Yuanbo; Chen, Zheng

    2018-01-01

    To realize a fast and smooth operating mode transition process from electric driving mode to engine-on driving mode, this paper presents a novel robust hierarchical mode transition control method for a plug-in hybrid electric bus (PHEB) with pre-transmission parallel hybrid powertrain. Firstly, the mode transition process is divided into five stages to clearly describe the powertrain dynamics. Based on the dynamics models of powertrain and clutch actuating mechanism, a hierarchical control structure including two robust H∞ controllers in both upper layer and lower layer is proposed. In upper layer, the demand clutch torque can be calculated by a robust H∞controller considering the clutch engaging time and the vehicle jerk. While in lower layer a robust tracking controller with L2-gain is designed to perform the accurate position tracking control, especially when the parameters uncertainties and external disturbance occur in the clutch actuating mechanism. Simulation and hardware-in-the-loop (HIL) test are carried out in a traditional driving condition of PHEB. Results show that the proposed hierarchical control approach can obtain the good control performance: mode transition time is greatly reduced with the acceptable jerk. Meanwhile, the designed control system shows the obvious robustness with the uncertain parameters and disturbance. Therefore, the proposed approach may offer a theoretical reference for the actual vehicle controller.

  20. Multidisciplinary Analysis and Control of High Performance Air Vehicles

    DTIC Science & Technology

    2005-05-06

    G (s)u(s) + Gf (s)f(s) (4) where {GP(s) = C(sl - A)-’B + D G1(s) =C(sl - A)-’R, + R2 From a practical point of view, it is reasonable to make no...between various dynamics that makes control of this class of vehicles very challenging. 5. Human Resource Development: The grant was used to attract...characteristics of AHF make modeling and control of AHFVs especially challenging. Due to the strong coupling between the aerodynamics, the airframe, and

  1. A Simulation Study of a Speed Control System for Autonomous On-Road Operation of Automotive Vehicles.

    DTIC Science & Technology

    1987-06-01

    by block numoiber) The study of human driving of automotive vehicles is an important aid to the development of viable autonomous vehicle navigation...of human driving which could provide some different insights into possible approaches to autonomous vehicle control. At the start of this work, it was...advanced work in the behavioral aspects of human driving . Research of this nature can have a significant impact on the development of autonomous vehicles

  2. Benefit of an operating vehicle preventing peritonitis in peritoneal dialysis patients: a retrospective, case-controlled study.

    PubMed

    Fang, Pan; Lu, Jia; Liu, Ying-Hong; Deng, Hong-Mei; Zhang, Lei; Zhang, Hong-Qing

    2018-06-01

    Peritonitis, which is one of the leading complications of peritoneal dialysis (PD) worldwide, severely affected morbidity and mortality of the PD patients. Although many efforts have been made to prevent PD-related peritonitis, it seems impossible to prevent it completely. Many causes have been reported to lead to peritonitis, and contamination during bag exchange is one of the important risk factors for peritonitis. Here, we introduce an operating vehicle, which we invented to provide a sterile and safe space for bag exchange. A single-center, retrospective, case-control study was undertaken to determine whether this operating vehicle has a protective role in preventing peritonitis. In total, 462 continuous ambulatory peritoneal dialysis patients were included in this study from October 2014 to March 2017. According to their personal will, these patients chose to use operating vehicle or traditional method during their bag exchange. The demographic, clinical and laboratory data of these patients in the two groups were collected, analyzed and compared. Of 462 patients with home dialysis, operating vehicle group consisted of 61 patients, and control group consisted of 401 patients. In the control group, over 677 patient-years, peritonitis occurred in 69 of 401 patients (17.2%), while in the operating vehicle group, over 60 patient-years, only 4 of 61 patients (6.6%) had episodes of peritonitis. The number of patients suffered from peritonitis was significantly decreased in the operating vehicle group (P = 0.034). Besides, there were a total of 99 episodes of peritonitis, and the rate was 1 episode every 7.2 patient-years in control group and 1 episode every 12 patient-years in the operating vehicle group. There was significant difference between the two groups (0.013). Positive dialysate cultures were obtained in majority of the peritonitis episodes (60.6%). Operating vehicle might help to reduce PD-related peritonitis by preventing contamination during bag

  3. H∞ robust fault-tolerant controller design for an autonomous underwater vehicle's navigation control system

    NASA Astrophysics Data System (ADS)

    Cheng, Xiang-Qin; Qu, Jing-Yuan; Yan, Zhe-Ping; Bian, Xin-Qian

    2010-03-01

    In order to improve the security and reliability for autonomous underwater vehicle (AUV) navigation, an H∞ robust fault-tolerant controller was designed after analyzing variations in state-feedback gain. Operating conditions and the design method were then analyzed so that the control problem could be expressed as a mathematical optimization problem. This permitted the use of linear matrix inequalities (LMI) to solve for the H∞ controller for the system. When considering different actuator failures, these conditions were then also mathematically expressed, allowing the H∞ robust controller to solve for these events and thus be fault-tolerant. Finally, simulation results showed that the H∞ robust fault-tolerant controller could provide precise AUV navigation control with strong robustness.

  4. Groundwater-saline lakes interaction - The contribution of saline groundwater circulation to solute budget of saline lakes: a lesson from the Dead Sea

    NASA Astrophysics Data System (ADS)

    Kiro, Yael; Weinstein, Yishai; Starinsky, Abraham; Yechieli, Yoseph

    2013-04-01

    Saline lakes act as base level for both surface water and groundwater. Thus, a change in lake levels is expected to result in changes in the hydrogeological system in its vicinity, exhibited in groundwater levels, location of the fresh-saline water interface, sub-lacustrine groundwater discharge (SGD) and saline water circulation. All these processes were observed in the declining Dead Sea system, whose water level dropped by ~35 meters in the last 50 years. This work focuses mainly on the effect of circulation of Dead Sea water in the aquifer, which continues even in this very rapid base level drop. In general, seawater circulation in coastal aquifers is now recognized as a major process affecting trace element mass balances in coastal areas. Estimates of submarine groundwater discharge (SGD) vary over several orders of magnitude (1-1000000 m3/yr per meter shoreline). These estimates are sensitive to fresh-saline SGD ratios and to the temporal and spatial scales of the circulation. The Dead Sea system is an excellent natural field lab for studying seawater-groundwater interaction and large-scale circulation due to the absence of tides and to the minor role played by waves. During Dead Sea water circulation in the aquifer several geochemical reactions occur, ranging from short-term adsorption-desorption reactions and up to long-term precipitation and dissolution reactions. These processes affect the trace element distribution in the saline groundwater. Barite and celestine, which are supersaturated in the lake water, precipitate during circulation in the aquifer, reducing barium (from 5 to 1.5 mg/L), strontium (from 350 to 300 mg/L) and the long-lived 226Ra (from 145 to 60 dpm/L) in the saline groundwater. Redox-controlled reactions cause a decrease in uranium from 2.4 to 0.1 μg/L, and an increase in iron from 1 to 13 mg/L. 228Ra (t1/2=5.75 yr) activity in the Dead Sea is ~1 dpm/L and increase gradually as the saline water flows further inland until reaching

  5. A study of flight control requirements for advanced, winged, earth-to-orbit vehicles with far-aft center-of-gravity locations

    NASA Technical Reports Server (NTRS)

    Hepler, A. K.; Zeck, H.; Walker, W. H.; Polack, A.

    1982-01-01

    Control requirements of Controlled Configured Design Approach vehicles with far-aft center of gravity locations are studied. The baseline system investigated is a fully reusable vertical takeoff/horizontal landing single stage-to-orbit vehicle with mission requirements similar to that of the space shuttle vehicle. Evaluations were made to determine dynamic stability boundaries, time responses, trim control, operational center-of-gravity limits, and flight control subsystem design requirements. Study tasks included a baseline vehicle analysis, an aft center of gravity study, a payload size study, and a technology assessment.

  6. Coordinated path-following and direct yaw-moment control of autonomous electric vehicles with sideslip angle estimation

    NASA Astrophysics Data System (ADS)

    Guo, Jinghua; Luo, Yugong; Li, Keqiang; Dai, Yifan

    2018-05-01

    This paper presents a novel coordinated path following system (PFS) and direct yaw-moment control (DYC) of autonomous electric vehicles via hierarchical control technique. In the high-level control law design, a new fuzzy factor is introduced based on the magnitude of longitudinal velocity of vehicle, a linear time varying (LTV)-based model predictive controller (MPC) is proposed to acquire the wheel steering angle and external yaw moment. Then, a pseudo inverse (PI) low-level control allocation law is designed to realize the tracking of desired external moment torque and management of the redundant tire actuators. Furthermore, the vehicle sideslip angle is estimated by the data fusion of low-cost GPS and INS, which can be obtained by the integral of modified INS signals with GPS signals as initial value. Finally, the effectiveness of the proposed control system is validated by the simulation and experimental tests.

  7. Simulation methods supporting homologation of Electronic Stability Control in vehicle variants

    NASA Astrophysics Data System (ADS)

    Lutz, Albert; Schick, Bernhard; Holzmann, Henning; Kochem, Michael; Meyer-Tuve, Harald; Lange, Olav; Mao, Yiqin; Tosolin, Guido

    2017-10-01

    Vehicle simulation has a long tradition in the automotive industry as a powerful supplement to physical vehicle testing. In the field of Electronic Stability Control (ESC) system, the simulation process has been well established to support the ESC development and application by suppliers and Original Equipment Manufacturers (OEMs). The latest regulation of the United Nations Economic Commission for Europe UN/ECE-R 13 allows also for simulation-based homologation. This extends the usage of simulation from ESC development to homologation. This paper gives an overview of simulation methods, as well as processes and tools used for the homologation of ESC in vehicle variants. The paper first describes the generic homologation process according to the European Regulation (UN/ECE-R 13H, UN/ECE-R 13/11) and U.S. Federal Motor Vehicle Safety Standard (FMVSS 126). Subsequently the ESC system is explained as well as the generic application and release process at the supplier and OEM side. Coming up with the simulation methods, the ESC development and application process needs to be adapted for the virtual vehicles. The simulation environment, consisting of vehicle model, ESC model and simulation platform, is explained in detail with some exemplary use-cases. In the final section, examples of simulation-based ESC homologation in vehicle variants are shown for passenger cars, light trucks, heavy trucks and trailers. This paper is targeted to give a state-of-the-art account of the simulation methods supporting the homologation of ESC systems in vehicle variants. However, the described approach and the lessons learned can be used as reference in future for an extended usage of simulation-supported releases of the ESC system up to the development and release of driver assistance systems.

  8. Shifting and power sharing control of a novel dual input clutchless transmission for electric vehicles

    NASA Astrophysics Data System (ADS)

    Liang, Jiejunyi; Yang, Haitao; Wu, Jinglai; Zhang, Nong; Walker, Paul D.

    2018-05-01

    To improve the overall efficiency of electric vehicles and guarantee the driving comfort and vehicle drivability under the concept of simplifying mechanism complexity and minimizing manufacturing cost, this paper proposes a novel clutchless power-shifting transmission system with shifting control strategy and power sharing control strategy. The proposed shifting strategy takes advantage of the transmission architecture to achieve power-on shifting, which greatly improves the driving comfort compared with conventional automated manual transmission, with a bump function based shifting control method. To maximize the overall efficiency, a real-time power sharing control strategy is designed to solve the power distribution problem between the two motors. Detailed mathematical model is built to verify the effectiveness of the proposed methods. The results demonstrate the proposed strategies considerably improve the overall efficiency while achieve non-interrupted power-on shifting and maintain the vehicle jerk during shifting under an acceptable threshold.

  9. Apparatus for stopping a vehicle

    DOEpatents

    Wattenburg, Willard H [Walnut Creek, CA; McCallen, David B [Livermore, CA

    2007-03-20

    An apparatus for externally controlling one or more brakes on a vehicle having a pressurized fluid braking system. The apparatus can include a pressurizable vessel that is adapted for fluid-tight coupling to the braking system. Impact to the rear of the vehicle by a pursuit vehicle, shooting a target mounted on the vehicle or sending a signal from a remote control can all result in the fluid pressures in the braking system of the vehicle being modified so that the vehicle is stopped and rendered temporarily inoperable. A control device can also be provided in the driver's compartment of the vehicle for similarly rendering the vehicle inoperable. A driver or hijacker of the vehicle preferably cannot overcome the stopping action from the driver's compartment.

  10. Designing neuro-fuzzy controller for electromagnetic anti-lock braking system (ABS) on electric vehicle

    NASA Astrophysics Data System (ADS)

    Pramudijanto, Josaphat; Ashfahani, Andri; Lukito, Rian

    2018-03-01

    Anti-lock braking system (ABS) is used on vehicles to keep the wheels unlocked in sudden break (inside braking) and minimalize the stop distance of the vehicle. The problem of it when sudden break is the wheels locked so the vehicle steering couldn’t be controlled. The designed ABS system will be applied on ABS simulator using the electromagnetic braking. In normal condition or in condition without braking, longitudinal velocity of the vehicle will be equal with the velocity of wheel rotation, so the slip ratio will be 0 (0%) and if the velocity of wheel rotation is 0 (in locked condition) then the wheels will be slip 1 (100%). ABS system will keep the value of slip ratio so it will be 0.2 (20%). In this final assignment, the method that is used is Neuro-Fuzzy method to control the slip value on the wheels. The input is the expectable slip and the output is slip from plant. The learning algorithm which is used is Backpropagation that will work by feedforward to get actual output and work by feedback to get error value with target output. The network that was made based on fuzzy mechanism which are fuzzification, inference and defuzzification, Neuro-fuzzy controller can reduce overshoot plant respond to 43.2% compared to plant respond without controller by open loop.

  11. Factors controlling the configuration of the fresh-saline water interface in the Dead Sea coastal aquifers: Synthesis of TDEM surveys and numerical groundwater modeling

    USGS Publications Warehouse

    Yechieli, Y.; Kafri, U.; Goldman, M.; Voss, C.I.

    2001-01-01

    TDEM (time domain electromagnetic) traverses in the Dead Sea (DS) coastal aquifer help to delineate the configuration of the interrelated fresh-water and brine bodies and the interface in between. A good linear correlation exists between the logarithm of TDEM resistivity and the chloride concentration of groundwater, mostly in the higher salinity range, close to that of the DS brine. In this range, salinity is the most important factor controlling resistivity. The configuration of the fresh-saline water interface is dictated by the hydraulic gradient, which is controlled by a number of hydrological factors. Three types of irregularities in the configuration of fresh-water and saline-water bodies were observed in the study area: 1. Fresh-water aquifers underlying more saline ones ("Reversal") in a multi-aquifer system. 2. "Reversal" and irregular residual saline-water bodies related to historical, frequently fluctuating DS base level and respective interfaces, which have not undergone complete flushing. A rough estimate of flushing rates may be obtained based on knowledge of the above fluctuations. The occurrence of salt beds is also a factor affecting the interface configuration. 3. The interface steepens towards and adjacent to the DS Rift fault zone. Simulation analysis with a numerical, variable-density flow model, using the US Geological Survey's SUTRA code, indicates that interface steep- ening may result from a steep water-level gradient across the zone, possibly due to a low hydraulic conductivity in the immediate vicinity of the fault.

  12. Optimization of shared autonomy vehicle control architectures for swarm operations.

    PubMed

    Sengstacken, Aaron J; DeLaurentis, Daniel A; Akbarzadeh-T, Mohammad R

    2010-08-01

    The need for greater capacity in automotive transportation (in the midst of constrained resources) and the convergence of key technologies from multiple domains may eventually produce the emergence of a "swarm" concept of operations. The swarm, which is a collection of vehicles traveling at high speeds and in close proximity, will require technology and management techniques to ensure safe, efficient, and reliable vehicle interactions. We propose a shared autonomy control approach, in which the strengths of both human drivers and machines are employed in concert for this management. Building from a fuzzy logic control implementation, optimal architectures for shared autonomy addressing differing classes of drivers (represented by the driver's response time) are developed through a genetic-algorithm-based search for preferred fuzzy rules. Additionally, a form of "phase transition" from a safe to an unsafe swarm architecture as the amount of sensor capability is varied uncovers key insights on the required technology to enable successful shared autonomy for swarm operations.

  13. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A number of problems related to the design, construction and evaluation of an autonomous roving planetary vehicle and its control and operating systems intended for an unmanned exploration of Mars are studied. Vehicle configuration, dynamics, control, systems and propulsion; systems analysis; terrain sensing and modeling and path selection; and chemical analysis of samples are included.

  14. Control performance of a road vehicle with four independent single-wheel electric motors and steer-by-wire system

    NASA Astrophysics Data System (ADS)

    Weiskircher, Thomas; Müller, Steffen

    2012-01-01

    This article presents a motion controller for a road vehicle equipped with a steer-by-wire system and four independent electric rim-mounted drives. The motion controller separates the control law from the specific actuator setup by the usage of virtual global control variables acting on the vehicle centre of gravity. A control allocation algorithm distributes the virtual control variables to the available actuators. An approximation of the real actuator dynamics is used to analyse the performance of different motion controller types in the linear and nonlinear driving regions. In addition, a vehicle state observer consisting of a traction force observer and an unscented Kalman filter is discussed to analyse the control behaviour in the case of a real sensor setup.

  15. Physiological short-term response to sudden salinity change in the Senegalese sole (Solea senegalensis).

    PubMed

    Herrera, Marcelino; Aragão, Cláudia; Hachero, Ismael; Ruiz-Jarabo, Ignacio; Vargas-Chacoff, Luis; Mancera, Juan Miguel; Conceição, Luis E C

    2012-12-01

    The physiological responses of Senegalese sole to a sudden salinity change were investigated. The fish were first acclimated to an initial salinity of 37.5 ppt for 4 h. Then, one group was subjected to increased salinity (55 ppt) while another group was subjected to decreased salinity (5 ppt). The third group (control group) remained at 37.5 ppt. We measured the oxygen consumption rate, osmoregulatory (plasma osmolality, gill and kidney Na(+),K(+)-ATPase activities) and stress (plasma cortisol and metabolites) parameters 0.5 and 3 h after transfer. Oxygen consumption at both salinities was higher than for the control at both sampling times. Gill Na(+),K(+)-ATPase activity was significantly higher for the 55 ppt salinity at 0.5 h. Plasma osmolality decreased in the fish exposed to 5 ppt at the two sampling times but no changes were detected for high salinities. Plasma cortisol levels significantly increased at both salinities, although these values declined in the low-salinity group 3 h after transfer. Plasma glucose at 5 ppt salinity did not vary significantly at 0.5 h but decreased at 3 h, while lactate increased for both treatments at the first sampling time and returned to the control levels at 3 h. Overall, the physiological response of S. senegalensis was immediate and involved a rise in oxygen consumption and plasma cortisol values as well as greater metabolite mobilization at both salinities.

  16. Salinity Improves Performance and Alters Distribution of Soybean Aphids.

    PubMed

    Eichele-Nelson, Jaclyn; DeSutter, Thomas; Wick, Abbey F; Harmon, Erin L; Harmon, Jason P

    2018-05-24

    We know numerous abiotic factors strongly influence crop plants. Yet we often know much less about abiotic effects on closely interacting organisms including herbivorous insects. This lack of a whole-system perspective may lead to underestimating the threats from changing factors. High soil salinity is a specific example that we know threatens crop plants in many places, but we need to know much more about how other organisms are also affected. We investigated how salinity affects the soybean aphid (SBA; Aphis glycines Matsumura; Hemiptera: Aphididae) on soybean plants (Glycine max [L.] Merr.; Fabales: Fabaceae) grown across a range of saline conditions. We performed four complementary greenhouse experiments to understand different aspects of how salinity might affect SBA. We found that as salinity increased both population size and fecundity of SBA increased across electrical conductivity values ranging from 0.84 to 8.07 dS m-1. Tracking individual aphids we also found they lived longer and produced more offspring in high saline conditions compared to the control. Moreover, we found that salinity influenced aphid distribution such that when given the chance aphids accumulated more on high-salinity plants. These results suggest that SBA could become a larger problem in areas with higher salinity and that those aphids may exacerbate the negative effects of salinity for soybean production.

  17. Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

    NASA Technical Reports Server (NTRS)

    Frederick, D. K.; Lashmet, P. K.; Moyer, W. R.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

    1973-01-01

    The following tasks related to the design, construction, and evaluation of a mobile planetary vehicle for unmanned exploration of Mars are discussed: (1) design and construction of a 0.5 scale dynamic vehicle; (2) mathematical modeling of vehicle dynamics; (3) experimental 0.4 scale vehicle dynamics measurements and interpretation; (4) vehicle electro-mechanical control systems; (5) remote control systems; (6) collapsibility and deployment concepts and hardware; (7) design, construction and evaluation of a wheel with increased lateral stiffness, (8) system design optimization; (9) design of an on-board computer; (10) design and construction of a laser range finder; (11) measurement of reflectivity of terrain surfaces; (12) obstacle perception by edge detection; (13) terrain modeling based on gradients; (14) laser scan systems; (15) path selection system simulation and evaluation; (16) gas chromatograph system concepts; (17) experimental chromatograph separation measurements and chromatograph model improvement and evaluation.

  18. Automatic control of the Skylab Astronaut Maneuvering Research Vehicle.

    NASA Technical Reports Server (NTRS)

    Murtagh, T. B.; Goodwin, M. A.; Greenlee, J. E.; Whitsett , C. E.

    1973-01-01

    The two automatic control modes of the Astronaut Maneuvering Research Vehicle (AMRV) are analyzed: the control moment gyro (CMG) and the rate gyro (RG). The AMRV is an autonomous maneuvering unit which translates and rotates the pilot by means of hand-controller input commands. The CMG normal operation, desaturation, and cage/lock dynamics are described in terms of a realistic AMRV mass property configuration. No propellant is used for normal operation in the CMG mode, and the maximum rotation rate is 5 deg/sec about each AMRV axis. The RG attitude maneuvering and limit cycle submode dynamic are described in terms of the same AMRV mass property configuration.

  19. Pore fluids and the LGM ocean salinity-Reconsidered

    NASA Astrophysics Data System (ADS)

    Wunsch, Carl

    2016-03-01

    Pore fluid chlorinity/salinity data from deep-sea cores related to the salinity maximum of the last glacial maximum (LGM) are analyzed using estimation methods deriving from linear control theory. With conventional diffusion coefficient values and no vertical advection, results show a very strong dependence upon initial conditions at -100 ky. Earlier inferences that the abyssal Southern Ocean was strongly salt-stratified in the LGM with a relatively fresh North Atlantic Ocean are found to be consistent within uncertainties of the salinity determination, which remain of order ±1 g/kg. However, an LGM Southern Ocean abyss with an important relative excess of salt is an assumption, one not required by existing core data. None of the present results show statistically significant abyssal salinity values above the global average, and results remain consistent, apart from a general increase owing to diminished sea level, with a more conventional salinity distribution having deep values lower than the global mean. The Southern Ocean core does show a higher salinity than the North Atlantic one on the Bermuda Rise at different water depths. Although much more sophisticated models of the pore-fluid salinity can be used, they will only increase the resulting uncertainties, unless considerably more data can be obtained. Results are consistent with complex regional variations in abyssal salinity during deglaciation, but none are statistically significant.

  20. Macroinformational analysis of conditions for controllability of space-vehicle orbit

    NASA Astrophysics Data System (ADS)

    Glazov, B. I.

    2011-12-01

    The general axiomatics of information measures for the macro analysis of relations of an information-cybernetic system in the control is introduced. The general structure of a semantically marked graph of open and closed relations of an information-cybernetic system between the participants in the environment, as well as thenecessary axiomatic and technological information-cybernetic system conditions of controllability and observability of objects, for the case of a space vehicle in orbit, are justified.

  1. Improved statistical method for temperature and salinity quality control

    NASA Astrophysics Data System (ADS)

    Gourrion, Jérôme; Szekely, Tanguy

    2017-04-01

    Climate research and Ocean monitoring benefit from the continuous development of global in-situ hydrographic networks in the last decades. Apart from the increasing volume of observations available on a large range of temporal and spatial scales, a critical aspect concerns the ability to constantly improve the quality of the datasets. In the context of the Coriolis Dataset for ReAnalysis (CORA) version 4.2, a new quality control method based on a local comparison to historical extreme values ever observed is developed, implemented and validated. Temperature, salinity and potential density validity intervals are directly estimated from minimum and maximum values from an historical reference dataset, rather than from traditional mean and standard deviation estimates. Such an approach avoids strong statistical assumptions on the data distributions such as unimodality, absence of skewness and spatially homogeneous kurtosis. As a new feature, it also allows addressing simultaneously the two main objectives of an automatic quality control strategy, i.e. maximizing the number of good detections while minimizing the number of false alarms. The reference dataset is presently built from the fusion of 1) all ARGO profiles up to late 2015, 2) 3 historical CTD datasets and 3) the Sea Mammals CTD profiles from the MEOP database. All datasets are extensively and manually quality controlled. In this communication, the latest method validation results are also presented. The method has already been implemented in the latest version of the delayed-time CMEMS in-situ dataset and will be deployed soon in the equivalent near-real time products.

  2. Architecture of a platform for hardware-in-the-loop simulation of flying vehicle control systems

    NASA Astrophysics Data System (ADS)

    Belokon', S. A.; Zolotukhin, Yu. N.; Filippov, M. N.

    2017-07-01

    A hardware-software platform is presented, which is designed for the development and hardware-in-the-loop simulation of flying vehicle control systems. This platform ensures the construction of the mathematical model of the plant, development of algorithms and software for onboard radioelectronic equipment and ground control station, and visualization of the three-dimensional model of the vehicle and external environment of the cockpit in the simulator training mode.

  3. Field Experiments using Telepresence and Virtual Reality to Control Remote Vehicles: Application to Mars Rover Missions

    NASA Technical Reports Server (NTRS)

    Stoker, Carol

    1994-01-01

    This paper will describe a series of field experiments to develop and demonstrate file use of Telepresence and Virtual Reality systems for controlling rover vehicles on planetary surfaces. In 1993, NASA Ames deployed a Telepresence-Controlled Remotely Operated underwater Vehicle (TROV) into an ice-covered sea environment in Antarctica. The goal of the mission was to perform scientific exploration of an unknown environment using a remote vehicle with telepresence and virtual reality as a user interface. The vehicle was operated both locally, from above a dive hole in the ice through which it was launched, and remotely over a satellite communications link from a control room at NASA's Ames Research center, for over two months. Remote control used a bidirectional Internet link to the vehicle control computer. The operator viewed live stereo video from the TROV along with a computer-gene rated graphic representation of the underwater terrain showing file vehicle state and other related information. Tile actual vehicle could be driven either from within the virtual environment or through a telepresence interface. In March 1994, a second field experiment was performed in which [lie remote control system developed for the Antarctic TROV mission was used to control the Russian Marsokhod Rover, an advanced planetary surface rover intended for launch in 1998. Marsokhod consists of a 6-wheel chassis and is capable of traversing several kilometers of terrain each day, The rover can be controlled remotely, but is also capable of performing autonomous traverses. The rover was outfitted with a manipulator arm capable of deploying a small instrument, collecting soil samples, etc. The Marsokhod rover was deployed at Amboy Crater in the Mojave desert, a Mars analog site, and controlled remotely from Los Angeles. in two operating modes: (1) a Mars rover mission simulation with long time delay and (2) a Lunar rover mission simulation with live action video. A team of planetary

  4. The problem of the driverless vehicle specified path stability control

    NASA Astrophysics Data System (ADS)

    Buznikov, S. E.; Endachev, D. V.; Elkin, D. S.; Strukov, V. O.

    2018-02-01

    Currently the effort of many leading foreign companies is focused on creation of driverless transport for transportation of cargo and passengers. Among many practical problems arising while creating driverless vehicles, the problem of the specified path stability control occupies a central place. The purpose of this paper is formalization of the problem in question in terms of the quadratic functional of the control quality, the comparative analysis of the possible solutions and justification of the choice of the optimum technical solution. As square value of the integral of the deviation from the specified path is proposed as the quadratic functional of the control quality. For generation of the set of software and hardware solution variants the Zwicky “morphological box” method is used within the hardware and software environments. The heading control algorithms use the wheel steering angle data and the deviation from the lane centerline (specified path) calculated based on the navigation data and the data from the video system. Where the video system does not detect the road marking, the control is carried out based on the wheel navigation system data and where recognizable road marking exits - based on to the video system data. The analysis of the test results allows making the conclusion that the application of the combined navigation system algorithms that provide quasi-optimum solution of the problem while meeting the strict functional limits for the technical and economic indicators of the driverless vehicle control system under development is effective.

  5. Characterization of particle bound organic carbon from diesel vehicles equipped with advanced emission control technologies.

    PubMed

    Pakbin, Payam; Ning, Zhi; Schauer, James J; Sioutas, Constantinos

    2009-07-01

    A chassis dynamometer study was carried out by the University of Southern California in collaboration with the Air Resources Board (CARB) to investigate the physical, chemical, and toxicological characteristics of diesel emissions of particulate matter (PM) from heavy-duty vehicles. These heavy-duty diesel vehicles (HDDV) were equipped with advanced emission control technologies, designed to meet CARB retrofit regulations. A HDDV without any emission control devices was used as the baseline vehicle. Three advanced emission control technologies; continuously regenerating technology (CRT), zeolite- and vanadium-based selective catalytic reduction technologies (Z-SCRT and V-SCRT), were tested under transient (UDDS) (1) and cruise (80 kmph) driving cycles to simulate real-world driving conditions. This paper focuses on the characterization of the particle bound organic species from the vehicle exhaust. Physical and chemical properties of PM emissions have been reported by Biswas et al. Atmos. Environ. 2008, 42, 5622-5634) and Hu et al. (Atmos. Environ. 2008, submitted) Significant reductions in the emission factors (microg/mile) of particle bound organic compounds were observed in HDDV equipped with advanced emission control technologies. V-SCRT and Z-SCRT effectively reduced PAHs, hopanes and steranes, n-alkanes and acids by more than 99%, and often to levels below detection limits for both cruise and UDDS cycles. The CRT technology also showed similar reductions with SCRT for medium and high molecular weight PAHs, acids, but with slightly lower removal efficiencies for other organic compounds. Ratios of particle bound organics-to-OC mass (microg/g) from the baseline exhaust were compared with their respective ratios in diesel fuel and lubricating oil, which revealed that hopanes and steranes originate from lubricating oil, whereas PAHs can either form during the combustion process or originate from diesel fuel itself. With the introduction of emission control

  6. Sliding Mode Control of Real-Time PNU Vehicle Driving Simulator and Its Performance Evaluation

    NASA Astrophysics Data System (ADS)

    Lee, Min Cheol; Park, Min Kyu; Yoo, Wan Suk; Son, Kwon; Han, Myung Chul

    This paper introduces an economical and effective full-scale driving simulator for study of human sensibility and development of new vehicle parts and its control. Real-time robust control to accurately reappear a various vehicle motion may be a difficult task because the motion platform is the nonlinear complex system. This study proposes the sliding mode controller with a perturbation compensator using observer-based fuzzy adaptive network (FAN). This control algorithm is designed to solve the chattering problem of a sliding mode control and to select the adequate fuzzy parameters of the perturbation compensator. For evaluating the trajectory control performance of the proposed approach, a tracking control of the developed simulator named PNUVDS is experimentally carried out. And then, the driving performance of the simulator is evaluated by using human perception and sensibility of some drivers in various driving conditions.

  7. 40 CFR 1037.620 - Shipment of incomplete vehicles to secondary vehicle manufacturers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Shipment of incomplete vehicles to secondary vehicle manufacturers. 1037.620 Section 1037.620 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Special Compliance Provisions § 1037.620...

  8. 40 CFR 1037.620 - Shipment of incomplete vehicles to secondary vehicle manufacturers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Shipment of incomplete vehicles to secondary vehicle manufacturers. 1037.620 Section 1037.620 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Special Compliance Provisions § 1037.620...

  9. 40 CFR 1037.620 - Shipment of incomplete vehicles to secondary vehicle manufacturers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Shipment of incomplete vehicles to secondary vehicle manufacturers. 1037.620 Section 1037.620 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Special Compliance Provisions § 1037.620...

  10. Master-Slave Control Scheme in Electric Vehicle Smart Charging Infrastructure

    PubMed Central

    Chung, Ching-Yen; Chynoweth, Joshua; Chu, Chi-Cheng; Gadh, Rajit

    2014-01-01

    WINSmartEV is a software based plug-in electric vehicle (PEV) monitoring, control, and management system. It not only incorporates intelligence at every level so that charge scheduling can avoid grid bottlenecks, but it also multiplies the number of PEVs that can be plugged into a single circuit. This paper proposes, designs, and executes many upgrades to WINSmartEV. These upgrades include new hardware that makes the level 1 and level 2 chargers faster, more robust, and more scalable. It includes algorithms that provide a more optimal charge scheduling for the level 2 (EVSE) and an enhanced vehicle monitoring/identification module (VMM) system that can automatically identify PEVs and authorize charging. PMID:24982956

  11. Modeling, Simulation, and Control of a Solar Electric Propulsion Vehicle in Near-Earth Vicinity Including Solar Array Degradation

    NASA Technical Reports Server (NTRS)

    Witzberger, Kevin (Inventor); Hojnicki, Jeffery (Inventor); Manzella, David (Inventor)

    2016-01-01

    Modeling and control software that integrates the complexities of solar array models, a space environment, and an electric propulsion system into a rigid body vehicle simulation and control model is provided. A rigid body vehicle simulation of a solar electric propulsion (SEP) vehicle may be created using at least one solar array model, at least one model of a space environment, and at least one model of a SEP propulsion system. Power availability and thrust profiles may be determined based on the rigid body vehicle simulation as the SEP vehicle transitions from a low Earth orbit (LEO) to a higher orbit or trajectory. The power availability and thrust profiles may be displayed such that a user can use the displayed power availability and thrust profiles to determine design parameters for an SEP vehicle mission.

  12. SPURS-2: Multi-month and multi-scale observations of upper ocean salinity in a rain-dominated salinity minimum region.

    NASA Astrophysics Data System (ADS)

    Rainville, L.; Farrar, J. T.; Shcherbina, A.; Centurioni, L. R.

    2017-12-01

    The Salinity Processes in the Upper-ocean Regional Study (SPURS) is a program aimed at understanding the patterns and variability of sea surface salinity. Following the first SPURS program in an evaporation-dominated region (2012-2013), the SPURS-2 program targeted wide range of spatial and temporal scales associated with processes controlling salinity in the rain-dominated Eastern Pacific Fresh Pool. Autonomous instruments were delivered in August and September 2016 using research vessels conducted observations over one complete annual cycle. The SPURS-2 field program used coordinated observations from many different autonomous platforms, and a mix of Lagrangian and Eulerian approaches. Here we discuss the motivation, implementation, and the early of SPURS-2.

  13. Towards cooperative guidance and control of highly automated vehicles: H-Mode and Conduct-by-Wire.

    PubMed

    Flemisch, Frank Ole; Bengler, Klaus; Bubb, Heiner; Winner, Hermann; Bruder, Ralph

    2014-01-01

    This article provides a general ergonomic framework of cooperative guidance and control for vehicles with an emphasis on the cooperation between a human and a highly automated vehicle. In the twenty-first century, mobility and automation technologies are increasingly fused. In the sky, highly automated aircraft are flying with a high safety record. On the ground, a variety of driver assistance systems are being developed, and highly automated vehicles with increasingly autonomous capabilities are becoming possible. Human-centred automation has paved the way for a better cooperation between automation and humans. How can these highly automated systems be structured so that they can be easily understood, how will they cooperate with the human? The presented research was conducted using the methods of iterative build-up and refinement of framework by triangulation, i.e. by instantiating and testing the framework with at least two derived concepts and prototypes. This article sketches a general, conceptual ergonomic framework of cooperative guidance and control of highly automated vehicles, two concepts derived from the framework, prototypes and pilot data. Cooperation is exemplified in a list of aspects and related to levels of the driving task. With the concept 'Conduct-by-Wire', cooperation happens mainly on the guidance level, where the driver can delegate manoeuvres to the automation with a specialised manoeuvre interface. With H-Mode, a haptic-multimodal interaction with highly automated vehicles based on the H(orse)-Metaphor, cooperation is mainly done on guidance and control with a haptically active interface. Cooperativeness should be a key aspect for future human-automation systems. Especially for highly automated vehicles, cooperative guidance and control is a research direction with already promising concepts and prototypes that should be further explored. The application of the presented approach is every human-machine system that moves and includes high

  14. Indoor Autonomous Control of a Two-Wheeled Inverted Pendulum Vehicle Using Ultra Wide Band Technology.

    PubMed

    Xia, Dunzhu; Yao, Yanhong; Cheng, Limei

    2017-06-15

    In this paper, we aimed to achieve the indoor tracking control of a two-wheeled inverted pendulum (TWIP) vehicle. The attitude data are acquired from a low cost micro inertial measurement unit (IMU), and the ultra-wideband (UWB) technology is utilized to obtain an accurate estimation of the TWIP's position. We propose a dual-loop control method to realize the simultaneous balance and trajectory tracking control for the TWIP vehicle. A robust adaptive second-order sliding mode control (2-RASMC) method based on an improved super-twisting (STW) algorithm is investigated to obtain the control laws, followed by several simulations to verify its robustness. The outer loop controller is designed using the idea of backstepping. Moreover, three typical trajectories, including a circle, a trifolium and a hexagon, have been designed to prove the adaptability of the control combinations. Six different combinations of inner and outer loop control algorithms have been compared, and the characteristics of inner and outer loop algorithm combinations have been analyzed. Simulation results demonstrate its tracking performance and thus verify the validity of the proposed control methods. Trajectory tracking experiments in a real indoor environment have been performed using our experimental vehicle to further validate the feasibility of the proposed algorithm in practice.

  15. Indoor Autonomous Control of a Two-Wheeled Inverted Pendulum Vehicle Using Ultra Wide Band Technology

    PubMed Central

    Xia, Dunzhu; Yao, Yanhong; Cheng, Limei

    2017-01-01

    In this paper, we aimed to achieve the indoor tracking control of a two-wheeled inverted pendulum (TWIP) vehicle. The attitude data are acquired from a low cost micro inertial measurement unit (IMU), and the ultra-wideband (UWB) technology is utilized to obtain an accurate estimation of the TWIP’s position. We propose a dual-loop control method to realize the simultaneous balance and trajectory tracking control for the TWIP vehicle. A robust adaptive second-order sliding mode control (2-RASMC) method based on an improved super-twisting (STW) algorithm is investigated to obtain the control laws, followed by several simulations to verify its robustness. The outer loop controller is designed using the idea of backstepping. Moreover, three typical trajectories, including a circle, a trifolium and a hexagon, have been designed to prove the adaptability of the control combinations. Six different combinations of inner and outer loop control algorithms have been compared, and the characteristics of inner and outer loop algorithm combinations have been analyzed. Simulation results demonstrate its tracking performance and thus verify the validity of the proposed control methods. Trajectory tracking experiments in a real indoor environment have been performed using our experimental vehicle to further validate the feasibility of the proposed algorithm in practice. PMID:28617338

  16. Seasonal/Yearly Salinity Variations in San Francisco Bay

    USGS Publications Warehouse

    Peterson, David H.; Cayan, Daniel R.; Dettinger, Michael D.; DiLeo, Jeanne Sandra; Hager, Stephen E.; Knowles, Noah; Nichols, Frederic H.; Schemel, Laurence E.; Smith, Richard E.; Uncles, Reginald J.

    1995-01-01

    The ability of resource agencies to manage fish, wildlife and freshwater supplies of San Francisco Bay estuary requires an integrated knowledge of the relations between the biota and their physical environment. A key factor in these relations is the role of salinity in determining both the physical and the biological character of the estuary. The saltiness of the water, and particularly its seasonal and interannual patterns of variability, affects which aquatic species live where within the estuary. Salinity also determines where water can and cannot be diverted for human consumption and irrigated agriculture, and plays a role in determining the capacity of the estuary to cleanse itself of wastes. In short, salinity is a fundamental property of estuarine physics and chemistry that, in turn, determines the biological characteristics of each estuary. Freshwater is a major control on estuarine salinity. Most freshwater supplied to the Bay is from river flow through the Delta, which is primarily runoff from the Sierra Nevada. Most contaminants in San Francisco Bay are from the Sacramento/San Joaquin Valley and the local watershed around the Bay rather than the sea or atmosphere. Land is the primary source of freshwater and freshwater serves as a tracer of land-derived substances such as the trace metals (copper, lead and selenium), pesticides and plant nutrients (nitrate and phosphate). The U.S. Geological Survey is collaborating with other agencies and institutions in studying San Francisco Bay salinity using field observations and numerical simulations to define the physical processes that control salinity. The issues that arise from salinity fluctuations, however, differ in the northern and southern parts of the bay. In North Bay we need to know how salinity responds to freshwater flow through the Sacramento/San Joaquin Delta; this knowledge will benefit water managers who determine how much delta flow is needed a) to protect freshwater supplies for municipal water

  17. Steering Control in a Low-Cost Driving Simulator: A Case for the Role of Virtual Vehicle Cab.

    PubMed

    Mecheri, Sami; Lobjois, Régis

    2018-04-01

    The aim of this study was to investigate steering control in a low-cost driving simulator with and without a virtual vehicle cab. In low-cost simulators, the lack of a vehicle cab denies driver access to vehicle width, which could affect steering control, insofar as locomotor adjustments are known to be based on action-scaled visual judgments of the environment. Two experiments were conducted in which steering control with and without a virtual vehicle cab was investigated in a within-subject design, using cornering and straight-lane-keeping tasks. Driving around curves without vehicle cab information made drivers deviate more from the lane center toward the inner edge in right (virtual cab = 4 ± 19 cm; no cab = 42 ± 28 cm; at the apex of the curve, p < .001) but not in left curves. More lateral deviation from the lane center toward the edge line was also found in driving without the virtual cab on straight roads (virtual cab = 21 ± 28 cm; no cab = 36 ± 27 cm; p < .001), whereas driving stability and presence ratings were not affected. In both experiments, the greater lateral deviation in the no-cab condition led to significantly more time driving off the lane. The findings strongly suggest that without cab information, participants underestimate the distance to the right edge of the car (in contrast to the left edge) and thus vehicle width. This produces considerable differences in the steering trajectory. Providing a virtual vehicle cab must be encouraged for more effectively capturing drivers' steering control in low-cost simulators.

  18. Surface-water salinity in the Gunnison River Basin, Colorado, water years 1989 through 2007

    USGS Publications Warehouse

    Schaffrath, Keelin R.

    2012-01-01

    Elevated levels of dissolved solids in water (salinity) can result in numerous and costly issues for agricultural, industrial, and municipal water users. The Colorado River Basin Salinity Control Act of 1974 (Public Law 93-320) authorized planning and construction of salinity-control projects in the Colorado River Basin. One of the first projects was the Lower Gunnison Unit, a project to mitigate salinity in the Lower Gunnison and Uncompahgre River Basins. In cooperation with the Bureau of Reclamation (USBR), the U.S. Geological Survey conducted a study to quantify changes in salinity in the Gunnison River Basin. Trends in salinity concentration and load during the period water years (WY) 1989 through 2004 (1989-2004) were determined for 15 selected streamflow-gaging stations in the Gunnison River Basin. Additionally, trends in salinity concentration and load during the period WY1989 through 2007 (1989-2007) were determined for 5 of the 15 sites for which sufficient data were available. Trend results also were used to identify regions in the Lower Gunnison River Basin (downstream from the Gunnison Tunnel) where the largest changes in salinity loads occur. Additional sources of salinity, including residential development (urbanization), changes in land cover, and natural sources, were estimated within the context of the trend results. The trend results and salinity loads estimated from trends testing also were compared to USBR and Natural Resources Conservation Service (NRCS) estimates of off-farm and on-farm salinity reduction from salinity-control projects in the basin. Finally, salinity from six additional sites in basins that are not affected by irrigated agriculture or urbanization was monitored from WY 2008 to 2010 to quantify what portion of salinity may be from nonagricultural or natural sources. In the Upper Gunnison area, which refers to Gunnison River Basin above the site located on the Gunnison River below the Gunnison Tunnel, estimated mean annual

  19. Absolute Salinity, ''Density Salinity'' and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

    NASA Astrophysics Data System (ADS)

    Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

    2011-01-01

    Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. However, the Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

  20. Absolute Salinity, "Density Salinity" and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10

    NASA Astrophysics Data System (ADS)

    Wright, D. G.; Pawlowicz, R.; McDougall, T. J.; Feistel, R.; Marion, G. M.

    2010-08-01

    Salinity plays a key role in the determination of the thermodynamic properties of seawater and the new TEOS-101 standard provides a consistent and effective approach to dealing with relationships between salinity and these thermodynamic properties. However, there are a number of practical issues that arise in the application of TEOS-10, both in terms of accuracy and scope, including its use in the reduction of field data and in numerical models. First, in the TEOS-10 formulation for IAPSO Standard Seawater, the Gibbs function takes the Reference Salinity as its salinity argument, denoted SR, which provides a measure of the mass fraction of dissolved material in solution based on the Reference Composition approximation for Standard Seawater. We discuss uncertainties in both the Reference Composition and the Reference-Composition Salinity Scale on which Reference Salinity is reported. The Reference Composition provides a much-needed fixed benchmark but modified reference states will inevitably be required to improve the representation of Standard Seawater for some studies. The Reference-Composition Salinity Scale should remain unaltered to provide a stable representation of salinity for use with the TEOS-10 Gibbs function and in climate change detection studies. Second, when composition anomalies are present in seawater, no single salinity variable can fully represent the influence of dissolved material on the thermodynamic properties of seawater. We consider three distinct representations of salinity that have been used in previous studies and discuss the connections and distinctions between them. One of these variables provides the most accurate representation of density possible as well as improvements over Reference Salinity for the determination of other thermodynamic properties. It is referred to as "Density Salinity" and is represented by the symbol SAdens; it stands out as the most appropriate representation of salinity for use in dynamical physical

  1. Start-Stop Moment Optimization of Range Extender and Control Strategy Design for Extended -Range Electric Vehicle

    NASA Astrophysics Data System (ADS)

    Zhao, Jing-bo; Han, Bing-yuan; Bei, Shao-yi

    2017-10-01

    Range extender is the core component of E-REV, its start-stop control determines the operation modes of vehicle. This paper based on a certain type of E-REV, researched constant power control strategy of range extender in extended-range model, to target range as constraint condition, combined with different driving cycle conditions, by correcting battery SOC for range extender start-stop moment, optimized the control strategy of range extender, and established the vehicle and range extender start-stop control simulation model. Selected NEDC and UDDS conditions simulation results show that: under certain target mileage, the range extender running time reduced by 37.2% and 28.2% in the NEDC condition, and running time UDDS conditions were reduced by 40.6% and 33.5% in the UDDS condition, reached the purpose of meeting the vehicle mileage and reducing consumption and emission.

  2. Space robot simulator vehicle

    NASA Technical Reports Server (NTRS)

    Cannon, R. H., Jr.; Alexander, H.

    1985-01-01

    A Space Robot Simulator Vehicle (SRSV) was constructed to model a free-flying robot capable of doing construction, manipulation and repair work in space. The SRSV is intended as a test bed for development of dynamic and static control methods for space robots. The vehicle is built around a two-foot-diameter air-cushion vehicle that carries batteries, power supplies, gas tanks, computer, reaction jets and radio equipment. It is fitted with one or two two-link manipulators, which may be of many possible designs, including flexible-link versions. Both the vehicle body and its first arm are nearly complete. Inverse dynamic control of the robot's manipulator has been successfully simulated using equations generated by the dynamic simulation package SDEXACT. In this mode, the position of the manipulator tip is controlled not by fixing the vehicle base through thruster operation, but by controlling the manipulator joint torques to achieve the desired tip motion, while allowing for the free motion of the vehicle base. One of the primary goals is to minimize use of the thrusters in favor of intelligent control of the manipulator. Ways to reduce the computational burden of control are described.

  3. 76 FR 55829 - Federal Motor Vehicle Safety Standards; Electronic Stability Control Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-09

    .... Benefits of ESC Electronic stability control (ESC) systems use automatic computer- controlled braking of... demonstrated that these systems reduce fatal single-vehicle crashes of passenger cars by 55 percent and fatal... potential to prevent 56 percent of the fatal passenger car rollovers and 74 percent of the fatal LTV first...

  4. Notification: Evaluating the Internal Controls for EPA's Vehicle Emissions Testing Program

    EPA Pesticide Factsheets

    Project #OPE-FY17-0009, Mar 6, 2017. The EPA OIG plans to begin preliminary research to determine whether the EPA’s existing internal controls are effective at detecting and preventing light-, medium-, and heavy-duty on-road vehicle emissions fraud.

  5. Indicators: Salinity

    EPA Pesticide Factsheets

    Salinity is the dissolved salt content of a body of water. Excess salinity, due to evaporation, water withdrawal, wastewater discharge, and other sources, is a chemical sterssor that can be toxic for aquatic environments.

  6. Reconstructing Past Ocean Salinity ((delta)18Owater)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guilderson, T P; Pak, D K

    2005-11-23

    Temperature and salinity are two of the key properties of ocean water masses. The distribution of these two independent but related characteristics reflects the interplay of incoming solar radiation (insolation) and the uneven distribution of heat loss and gain by the ocean, with that of precipitation, evaporation, and the freezing and melting of ice. Temperature and salinity to a large extent, determine the density of a parcel of water. Small differences in temperature and salinity can increase or decrease the density of a water parcel, which can lead to convection. Once removed from the surface of the ocean where 'local'more » changes in temperature and salinity can occur, the water parcel retains its distinct relationship between (potential) temperature and salinity. We can take advantage of this 'conservative' behavior where changes only occur as a result of mixing processes, to track the movement of water in the deep ocean (Figure 1). The distribution of density in the ocean is directly related to horizontal pressure gradients and thus (geostrophic) ocean currents. During the Quaternary when we have had systematic growth and decay of large land based ice sheets, salinity has had to change. A quick scaling argument following that of Broecker and Peng [1982] is: the modern ocean has a mean salinity of 34.7 psu and is on average 3500m deep. During glacial maxima sea level was on the order of {approx}120m lower than present. Simply scaling the loss of freshwater (3-4%) requires an average increase in salinity a similar percentage or to {approx}35.9psu. Because much of the deep ocean is of similar temperature, small changes in salinity have a large impact on density, yielding a potentially different distribution of water masses and control of the density driven (thermohaline) ocean circulation. It is partly for this reason that reconstructions of past salinity are of interest to paleoceanographers.« less

  7. 76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-03

    ... be equipped with an electronic control module (ECM) that is capable of limiting the maximum speed of the vehicle. 2. The ECM shall be set at no more than 68 mph by the manufacturer. 3. The ECM should be... ECM to be adjusted to let the vehicle exceed 68 mph. 4. Immediately upon the rule taking effect...

  8. [Effects of Suaeda glauca planting and straw mulching on soil salinity dynamics and desalination in extremely heavy saline soil of coastal areas.

    PubMed

    Zhang, Jiao; Cui, Shi You; Feng, Zhi Xiang

    2018-05-01

    To elucidate the seasonal variations in soil salinity and its driving factors, and to explore the effects of planting Suaeda glauca and straw mulching on soil desalination and salinity controlling, a field experiment was conducted in extremely heavy saline soil of coastal areas in Rudong, Jiangsu Province. There were four treatments: control (bare land, CK), planting S. glauca (PS), straw mulching A (at 15 t·hm -2 , SM-A), straw mulching 2A (at 30 t·hm -2 , SM-2A). Climate factors (including rainfall, atmospheric temperature, sunshine duration, and atmospheric evaporation) and soil salinity dynamic changes were determined from May 2014 to May 2015. Results showed that: (1) The seasonal variation of soil salinity was obvious in the bare ground (CK), with the lowest (8.69 g·kg -1 ) during June-August and the highest (26.66 g·kg -1 ) during September-December. The changes of soil salinity in topsoil (0-20 cm) were more intense than that in sub-topsoil (20-40 cm), with the changes in sub-topsoil having somewhat time lag compared the topsoil. (2) Soil salinity in CK treatment had a significantly linear correlation with the cumulative rainfall and evaporation-precipitation ratio of the fifteen-day before sampling. The results from multifactor and interphase analysis indicated that the increases of rainfall would promote soil desalinization. The rise of atmospheric temperature could exacerbate soil salt accumulation in surface soil. The interaction between rainfall and atmospheric temperature would have a positive effect on soil salt accumulation. (3) PS treatment did not alter the seasonal variation in soil salinity, but it reduced soil salinity in topsoil. (4) In SM-A and SM-2A treatments, the relationship of soil desalinization rate (%, Y) and treatment time (days, X) was expressed as Logistic curve equation. Moreover, the soil desalination rate was over 95.0% in the topsoil after 90-100 days of straw mul-ching treatment and was over 92.0% in sub-topsoil after 120

  9. City-specific vehicle emission control strategies to achieve stringent emission reduction targets in China's Yangtze River Delta region.

    PubMed

    Zhang, Shaojun; Wu, Ye; Zhao, Bin; Wu, Xiaomeng; Shu, Jiawei; Hao, Jiming

    2017-01-01

    The Yangtze River Delta (YRD) region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality. Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants (e.g., CO, HC and PM 2.5 ) in the YRD region. Even in Shanghai, where the emission control implemented are more stringent than in Jiangsu and Zhejiang, we observed little to no reduction in NOx emissions from 2000 to 2010. Emission-reduction targets for HC, NOx and PM 2.5 are determined using a response surface modeling tool for better air quality. We design city-specific emission control strategies for three vehicle-populated cities in the YRD region: Shanghai and Nanjing and Wuxi in Jiangsu. Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards, the limitation of vehicle population and usage, and the scrappage of older vehicles is applied, Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020. Therefore, additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles. Copyright © 2016. Published by Elsevier B.V.

  10. Salinity control in a clay soil beneath an orchard irrigated with treated waste water in the presence of a high water table: A numerical study

    NASA Astrophysics Data System (ADS)

    Russo, David; Laufer, Asher; Bardhan, Gopali; Levy, Guy J.

    2015-12-01

    A citrus orchard planted on a structured, clay soil associated with a high water table, irrigated by drip irrigation system using treated waste water (TWW) and local well water (LWW) was considered here. The scope of the present study was to analyze transport of mixed-ion, interacting salts in a combined vadose zone-groundwater flow system focusing on the following issues: (i) long-term effects of irrigation with TWW on the response of the flow system, identifying the main factors (e.g., soil salinity, soil sodicity) that control these effects, and (ii) salinity control aiming at improving both crop productivity and groundwater quality. To pursue this two-fold goal, 3-D numerical simulations of field-scale flow and transport were performed for an extended period of time, considering realistic features of the soil, water table, crop, weather and irrigation, and the coupling between the flow and the transport through the dependence of the soil hydraulic functions, K(ψ) and θ(ψ), on soil solution concentration C, and sodium adsorption ratio, SAR. Results of the analyses suggest that in the case studied, the long-term effect of irrigation with TWW on the response of the flow system is attributed to the enhanced salinity of the TWW, and not to the increase in soil sodicity. The latter findings are attributed to: (i) the negative effect of soil salinity on water uptake, and the tradeoff between water uptake and drainage flux, and, concurrently, solute discharge below the root zone; and, (ii) the tradeoff between the effects of C and SAR on K(ψ) and θ(ψ). Furthermore, it was demonstrated that a data-driven protocol for soil salinity control, based on alternating irrigation water quality between TWW and desalinized water, guided by the soil solution salinity at the centroid of the soil volume active in water uptake, may lead to a substantial increase in crop yield, and to a substantial decrease in the salinity load in the groundwater.

  11. The Heavy Vehicle Study: a case-control study investigating risk factors for crash in long distance heavy vehicle drivers in Australia

    PubMed Central

    2010-01-01

    Background Heavy vehicle transportation continues to grow internationally; yet crash rates are high, and the risk of injury and death extends to all road users. The work environment for the heavy vehicle driver poses many challenges; conditions such as scheduling and payment are proposed risk factors for crash, yet the precise measure of these needs quantifying. Other risk factors such as sleep disorders including obstructive sleep apnoea have been shown to increase crash risk in motor vehicle drivers however the risk of heavy vehicle crash from this and related health conditions needs detailed investigation. Methods and Design The proposed case control study will recruit 1034 long distance heavy vehicle drivers: 517 who have crashed and 517 who have not. All participants will be interviewed at length, regarding their driving and crash history, typical workloads, scheduling and payment, trip history over several days, sleep patterns, health, and substance use. All participants will have administered a nasal flow monitor for the detection of obstructive sleep apnoea. Discussion Significant attention has been paid to the enforcement of legislation aiming to deter problems such as excess loading, speeding and substance use; however, there is inconclusive evidence as to the direction and strength of associations of many other postulated risk factors for heavy vehicle crashes. The influence of factors such as remuneration and scheduling on crash risk is unclear; so too the association between sleep apnoea and the risk of heavy vehicle driver crash. Contributory factors such as sleep quality and quantity, body mass and health status will be investigated. Quantifying the measure of effect of these factors on the heavy vehicle driver will inform policy development that aims toward safer driving practices and reduction in heavy vehicle crash; protecting the lives of many on the road network. PMID:20338064

  12. Saline infusion sonohysterography.

    PubMed

    2004-01-01

    Saline infusion sonohysterography consists of ultrasonographic imaging of the uterus and uterocervical cavity, using real-time ultrasonography during injection of sterile saline into the uterus. When properly performed, saline infusion sonohysterography can provide information about the uterus and endometrium. The most common indication for sonohysterography is abnormal uterine bleeding. sonohysterography should not be performed in a woman who is pregnant or could be pregnant or in a woman with a pelvic infection or unexplained pelvic tenderness. Physicians who perform or supervise diagnostic saline infusion sonohysterograpy should have training, experience, and demonstrated competence in gynecologic ultrasonography and saline infusion sonohysterography. Portions of this document were developed jointly with the American College of Radiology and the American Institute of Ultrasound in Medicine.

  13. Chemical and stable carbon isotopic composition of PM2.5 from on-road vehicle emissions in the PRD region and implication for vehicle emission control policy

    NASA Astrophysics Data System (ADS)

    Dai, S.; Bi, X.; Chan, L. Y.; He, J.; Wang, B.; Wang, X.; Sheng, G.; Fu, J.

    2014-11-01

    Vehicle emission is a major source of urban air pollution. In recent decade, the Chinese government has introduced a range of policies to reduce the vehicle emission. In order to understand the chemical characteristics of PM2.5 from on-road vehicle emission in the Pearl River Delta (PRD) region and to evaluate the effectiveness of control policies on vehicles emission, the emission factors of PM2.5 mass, elemental carbon (EC), organic carbon (OC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSII), metal elements, organic compounds and stable carbon isotopic composition were measured in the Zhujiang Tunnel of Guangzhou, the PRD region of China in 2013. Emission factors of PM2.5 mass, OC, EC, and WSOC were 92.4, 16.7, 16.4, and 1.31 mg vehicle-1 km-1 respectively. Emission factors of WSII were 0.016 (F-) ~4.17 (Cl-) mg vehicle-1 km-1, totally contributing about 9.8% to the PM2.5 emissions. The sum of 27 measured metal elements accounted for 15.2% of the PM2.5 emissions. Fe was the most abundant metal element, with an emission factor of 3.91 mg vehicle-1 km-1. Emission factors of organic compounds including n-alkanes, PAHs, hopanes, and steranes were 91.9, 5.02, 32.0 and 7.59 μg vehicle-1 km-1, respectively. Stable carbon isotopic composition δ13C value was measured and it was -25.0‰ on average. An isotopic fractionation of 3.2‰ was found during fuel combustion. Compared with a previous study in Zhujiang Tunnel in year 2004, emission factors of PM2.5 mass, EC, OC, WSII except Cl-, and organic compounds decreased by 16.0-93.4%, which could be attributed to emission control policy from 2004 to 2013. However, emission factors of most of the metal elements increased significantly, which could be partially attributed to the changes in motor oil additives and vehicle condition. There are no mandatory national standards to limit metal content from vehicle emission, which should be a concern of the government. A snapshot of the 2013 characteristic

  14. Chemical and stable carbon isotopic composition of PM2.5 from on-road vehicle emissions in the PRD region and implications for vehicle emission control policy

    NASA Astrophysics Data System (ADS)

    Dai, S.; Bi, X.; Chan, L. Y.; He, J.; Wang, B.; Wang, X.; Peng, P.; Sheng, G.; Fu, J.

    2015-03-01

    Vehicle emissions are a major source of urban air pollution. In recent decade, the Chinese government has introduced a range of policies to reduce vehicle emissions. In order to understand the chemical characteristics of PM2.5 from on-road vehicle emissions in the Pearl River Delta (PRD) region and to evaluate the effectiveness of control policies on vehicle emissions, the emission factors of PM2.5 mass, elemental carbon (EC), organic carbon (OC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSII), metal elements, organic compounds and stable carbon isotopic composition were measured in the Zhujiang tunnel of Guangzhou, in the PRD region of China in 2013. Emission factors of PM2.5 mass, OC, EC and WSOC were 92.4, 16.7, 16.4 and 1.31 mg vehicle-1 km-1 respectively. Emission factors of WSII were 0.016 (F-) ~ 4.17 (Cl-) mg vehicle-1 km-1, contributing about 9.8% to the PM2.5 emissions. The sum of 27 measured metal elements accounted for 15.2% of PM2.5 emissions. Fe was the most abundant metal element, with an emission factor of 3.91 mg vehicle-1 km-1. Emission factors of organic compounds including n-alkanes, polycyclic aromatic hydrocarbons, hopanes and steranes were 91.9, 5.02, 32.0 and 7.59 μg vehicle-1 km-1, respectively. Stable carbon isotopic composition δ13C value was -25.0‰ on average. An isotopic fractionation of 3.2‰ was found during fuel combustion. Compared to a previous study in Zhujiang tunnel in 2004, emission factors of PM2.5mass, EC, OC, WSII except Cl- and organic compounds decreased by 16.0 ~ 93.4%, which could be attributed to emission control policy from 2004 to 2013. However, emission factors of most of the metal elements increased significantly, which could be partially attributed to the changes in motor oil additives and vehicle conditions. There are no mandatory national standards to limit metal content from vehicle emissions, which should be a concern of the government. A snapshot of the 2013 characteristic

  15. Warming and Inhibition of Salinization at the Ocean's Surface by Cyanobacteria

    NASA Astrophysics Data System (ADS)

    Wurl, O.; Bird, K.; Cunliffe, M.; Landing, W. M.; Miller, U.; Mustaffa, N. I. H.; Ribas-Ribas, M.; Witte, C.; Zappa, C. J.

    2018-05-01

    This paper describes high-resolution in situ observations of temperature and, for the first time, of salinity in the uppermost skin layer of the ocean, including the influence of large surface blooms of cyanobacteria on those skin properties. In the presence of the blooms, large anomalies of skin temperature and salinity of 0.95°C and -0.49 practical salinity unit were found, but a substantially cooler (-0.22°C) and saltier skin layer (0.19 practical salinity unit) was found in the absence of surface blooms. The results suggest that biologically controlled warming and inhibition of salinization of the ocean's surface occur. Less saline skin layers form during precipitation, but our observations also show that surface blooms of Trichodesmium sp. inhibit evaporation decreasing the salinity at the ocean's surface. This study has important implications in the assessment of precipitation over the ocean using remotely sensed salinity, but also for a better understanding of heat exchange and the hydrologic cycle on a regional scale.

  16. Saline irrigation for the management of skin extravasation injury in neonates.

    PubMed

    Gopalakrishnan, P N; Goel, N; Banerjee, Sujoy

    2012-02-15

    Extravasation injury is a common complication of neonatal intensive care and can result in scarring with cosmetic and functional sequelae. A wide variety of treatments are used in practice including subcutaneous irrigation with saline (with or without hyaluronidase), liposuction, use of specific antidotes, different topical applications and normal wound care with dry or wet dressings. All such treatments aim to prevent or reduce the severity of complications. To determine the efficacy and safety of saline irrigation or saline irrigation with prior hyaluronidase infiltration on tissue healing in neonates with extravasation injury when compared to no intervention or normal wound care. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 2), MEDLINE (1950 to June 2011), EMBASE (Jan 1980 to June 2011), CINAHL (Jan 1988 to June 2011) and the Web of Science (up to July 2011). Randomised controlled trials (RCT) and quasi-randomised controlled trials comparing saline irrigation with or without hyaluronidase infiltration with no intervention or normal wound care in the management of extravasation injury in neonates. Three review authors independently reviewed and identified articles for possible inclusion in this review. No eligible studies were found. There were a few case reports and case series describing successful outcomes with different interventions in this condition. To date, no randomised controlled trial is available that examines the effects of saline irrigation with or without prior hyaluronidase infiltration in the management of extravasation injury in neonates. Saline irrigation is a frequently reported intervention in the literature that is used in the management of extravasation injury in neonates. Research should be initially directed at evaluating the efficacy and safety of this intervention through randomised controlled trials. It will also be important to determine the size of the effect according to

  17. Hydrogen-rich saline attenuates spinal cord hemisection-induced testicular injury in rats.

    PubMed

    Ge, Li; Wei, Li-Hua; Du, Chang-Qing; Song, Guo-Hua; Xue, Ya-Zhuo; Shi, Hao-Shen; Yang, Ming; Yin, Xin-Xin; Li, Run-Ting; Wang, Xue-Er; Wang, Zhen; Song, Wen-Gang

    2017-06-27

    To study how hydrogen-rich saline (HS) promotes the recovery of testicular biological function in a hemi-sectioned spinal cord injury (hSCI) rat model, a right hemisection was performed at the T11-T12 of the spinal cord in Wistar rats. Animals were divided into four groups: normal group; vehicle group: sham-operated rats administered saline; hSCI group: subjected to hSCI and administered saline; HRST group: subjected to hSCI and administered HS. Hind limb neurological function, testis index, testicular morphology, mean seminiferous tubular diameter (MSTD) and seminiferous epithelial thickness (MSET), the expression of heme oxygenase-1 (HO-1), mitofusin-2 (MFN-2), and high-mobility group box 1 (HMGB-1), cell ultrastructure, and apoptosis of spermatogenic cells were studied. The results indicated that hSCI significantly decreased the hind limb neurological function, testis index, MSTD, and MSET, and induced severe testicular morphological injury. The MFN-2 level was decreased, and HO-1 and HMGB-1 were overexpressed in testicular tissues. In addition, hSCI accelerated the apoptosis of spermatogenic cells and the ultrastructural damage of cells in the hypophysis and testis. After HS administration, all these parameters were considerably improved, and the characteristics of hSCI testes were similar to those of normal control testes. Taken together, HS administration can promote the recovery of testicular biological function by anti-oxidative, anti-inflammatory, and anti-apoptotic action. More importantly, HS can inhibit the hSCI-induced ultrastructural changes in gonadotrophs, ameliorate the abnormal regulation of the hypothalamic-pituitary-testis axis, and thereby promote the recovery of testicular injury. HS administration also inhibited the hSCI-induced ultrastructural changes in testicular spermatogenic cells, Sertoli cells and interstitial cells.

  18. Hydrogen-rich saline attenuates spinal cord hemisection-induced testicular injury in rats

    PubMed Central

    Ge, Li; Wei, Li-Hua; Du, Chang-Qing; Song, Guo-Hua; Xue, Ya-Zhuo; Shi, Hao-Shen; Yang, Ming; Yin, Xin-Xin; Li, Run-Ting; Wang, Xue-er; Wang, Zhen; Song, Wen-Gang

    2017-01-01

    To study how hydrogen-rich saline (HS) promotes the recovery of testicular biological function in a hemi-sectioned spinal cord injury (hSCI) rat model, a right hemisection was performed at the T11–T12 of the spinal cord in Wistar rats. Animals were divided into four groups: normal group; vehicle group: sham-operated rats administered saline; hSCI group: subjected to hSCI and administered saline; HRST group: subjected to hSCI and administered HS. Hind limb neurological function, testis index, testicular morphology, mean seminiferous tubular diameter (MSTD) and seminiferous epithelial thickness (MSET), the expression of heme oxygenase-1 (HO-1), mitofusin-2 (MFN-2), and high-mobility group box 1 (HMGB-1), cell ultrastructure, and apoptosis of spermatogenic cells were studied. The results indicated that hSCI significantly decreased the hind limb neurological function, testis index, MSTD, and MSET, and induced severe testicular morphological injury. The MFN-2 level was decreased, and HO-1 and HMGB-1 were overexpressed in testicular tissues. In addition, hSCI accelerated the apoptosis of spermatogenic cells and the ultrastructural damage of cells in the hypophysis and testis. After HS administration, all these parameters were considerably improved, and the characteristics of hSCI testes were similar to those of normal control testes. Taken together, HS administration can promote the recovery of testicular biological function by anti-oxidative, anti-inflammatory, and anti-apoptotic action. More importantly, HS can inhibit the hSCI-induced ultrastructural changes in gonadotrophs, ameliorate the abnormal regulation of the hypothalamic-pituitary-testis axis, and thereby promote the recovery of testicular injury. HS administration also inhibited the hSCI-induced ultrastructural changes in testicular spermatogenic cells, Sertoli cells and interstitial cells. PMID:28404953

  19. Neural-network-based navigation and control of unmanned aerial vehicles for detecting unintended emissions

    NASA Astrophysics Data System (ADS)

    Zargarzadeh, H.; Nodland, David; Thotla, V.; Jagannathan, S.; Agarwal, S.

    2012-06-01

    Unmanned Aerial Vehicles (UAVs) are versatile aircraft with many applications, including the potential for use to detect unintended electromagnetic emissions from electronic devices. A particular area of recent interest has been helicopter unmanned aerial vehicles. Because of the nature of these helicopters' dynamics, high-performance controller design for them presents a challenge. This paper introduces an optimal controller design via output feedback control for trajectory tracking of a helicopter UAV using a neural network (NN). The output-feedback control system utilizes the backstepping methodology, employing kinematic, virtual, and dynamic controllers and an observer. Optimal tracking is accomplished with a single NN utilized for cost function approximation. The controller positions the helicopter, which is equipped with an antenna, such that the antenna can detect unintended emissions. The overall closed-loop system stability with the proposed controller is demonstrated by using Lyapunov analysis. Finally, results are provided to demonstrate the effectiveness of the proposed control design for positioning the helicopter for unintended emissions detection.

  20. Advanced underground Vehicle Power and Control: The locomotive Research Platform

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Vehicle Projects LLC

    2003-01-28

    Develop a fuelcell mine locomotive with metal-hydride hydrogen storage. Test the locomotive for fundamental limitations preventing successful commercialization of hydride fuelcells in underground mining. During Phase 1 of the DOE-EERE sponsored project, FPI and its partner SNL, completed work on the development of a 14.4 kW fuelcell power plant and metal-hydride energy storage. An existing battery-electric locomotive with similar power requirements, minus the battery module, was used as the base vehicle. In March 2001, Atlas Copco Wagner of Portland, OR, installed the fuelcell power plant into the base vehicle and initiated integration of the system into the vehicle. The entiremore » vehicle returned to Sandia in May 2001 for further development and integration. Initial system power-up took place in December 2001. A revision to the original contract, Phase 2, at the request of DOE Golden Field Office, established Vehicle Projects LLC as the new prime contractor,. Phase 2 allowed industry partners to conduct surface tests, incorporate enhancements to the original design by SNL, perform an extensive risk and safety analysis, and test the fuelcell locomotive underground under representative production mine conditions. During the surface tests one of the fuelcell stacks exhibited reduced power output resulting in having to replace both fuelcell stacks. The new stacks were manufactured with new and improved technology resulting in an increase of the gross power output from 14.4 kW to 17 kW. Further work by CANMET and Hatch Associates, an engineering consulting firm specializing in safety analysis for the mining industry, both under subcontract to Vehicle Projects LLC, established minimum requirements for underground testing. CANMET upgraded the Programmable Logic Control (PLC) software used to monitor and control the fuelcell power plant, taking into account locomotive operator's needs. Battery Electric, a South Africa manufacturer, designed and manufactured (at no

  1. Postprocedural pain in shoulder arthrography: differences between using preservative-free normal saline and normal saline with benzyl alcohol as an intraarticular contrast diluent.

    PubMed

    Storey, Troy F; Gilbride, George; Clifford, Kelly

    2014-11-01

    The purpose of this study was to prospectively evaluate the effect of benzyl alcohol, a common preservative in normal saline, on postprocedural pain after intraarticular injection for direct shoulder MR arthrography. From April 2011 through January 2013, 138 patients underwent direct shoulder MR arthrography. Using the Wong-Baker Faces Pain Scale, patients were asked to report their shoulder pain level immediately before and immediately after the procedure and then were contacted by telephone 6, 24, and 48 hours after the procedure. Fourteen patients did not receive the prescribed amount of contrast agent for diagnostic reasons or did not complete follow-up. Sixty-two patients received an intraarticular solution including preservative-free normal saline (control group) and 62 patients received an intraarticular solution including normal saline with 0.9% benzyl alcohol as a contrast diluent (test group). Patients were randomized as to which intraarticular diluent they received. Fluoroscopic and MR images were reviewed for extracapsular contrast agent administration or extravasation, full-thickness rotator cuff tears, and adhesive capsulitis. The effect of preservative versus control on pain level was estimated with multiple regression, which included time after procedure as the covariate and accounted for repeated measures over patients. Pain scale scores were significantly (p = 0.0382) higher (0.79 units; 95% CI, 0.034-1.154) with benzyl alcohol preservative compared with control (saline). In both study arms, the pain scale scores decreased slightly after the procedure, increased by roughly 1 unit over baseline for the test group and 0.3 unit over baseline for the control group by 6 hours after the procedure, were 0.50 unit over baseline for the test group and 0.12 unit over baseline for the control group at 24 hours, then fell to be slightly greater than baseline at 48 hours with benzyl alcohol and slightly less than baseline without benzyl alcohol. These trends

  2. Analysis of Instantaneous Attractive-Normal Force and Vertical Vibration Control of Combined-Levitation-and-Propulsion SLIM Vehicle

    NASA Astrophysics Data System (ADS)

    Yoshida, Takashi

    Combined-levitation-and-propulsion single-sided linear induction motor (SLIM) vehicle can be levitated without any additional levitation system. When the vehicle runs, the attractive-normal force varies depending on the phase of primary current because of the short primary end effect. The ripple of the attractive-normal force causes the vertical vibration of the vehicle. In this paper, instantaneous attractive-normal force is analyzed by using space harmonic analysis method. And based on the analysis, vertical vibration control is proposed. The validity of the proposed control method is verified by numerical simulation.

  3. Automatic control of a robotic vehicle

    NASA Technical Reports Server (NTRS)

    Mcreynolds, S. R.

    1976-01-01

    Over the last several years Jet Propulsion Laboratory has been engaged in a project to develop some of the technology required to build a robotic vehicle for exploring planetary surfaces. An overview of hardware and software being developed for this project is given. Particular emphasis is placed on the description of the current design for the Vehicle System required for locomotion and the path planning algorithm.

  4. RFID-based vehicle positioning and its applications in connected vehicles.

    PubMed

    Wang, Jianqiang; Ni, Daiheng; Li, Keqiang

    2014-03-04

    This paper proposed an RFID-based vehicle positioning approach to facilitate connected vehicles applications. When a vehicle passes over an RFID tag, the vehicle position is given by the accurate position stored in the tag. At locations without RFID coverage, the vehicle position is estimated from the most recent tag location using a kinematics integration algorithm till updates from the next tag. The accuracy of RFID positioning is verified empirically in two independent ways with one using radar and the other a photoelectric switch. The former is designed to verify whether the dynamic position obtained from RFID tags matches the position measured by radar that is regarded as accurate. The latter aims to verify whether the position estimated from the kinematics integration matches the position obtained from RFID tags. Both means supports the accuracy of RFID-based positioning. As a supplement to GPS which suffers from issues such as inaccuracy and loss of signal, RFID positioning is promising in facilitating connected vehicles applications. Two conceptual applications are provided here with one in vehicle operational control and the other in Level IV intersection control.

  5. Combined effects of seawater acidification and salinity changes in Ruditapes philippinarum.

    PubMed

    Velez, Catia; Figueira, Etelvina; Soares, Amadeu M V M; Freitas, Rosa

    2016-07-01

    Due to human activities, predictions for the coming years indicate increasing frequency and intensity of extreme weather events (rainy and drought periods) and pollution levels, leading to salinity shifts and ocean acidification. Therefore, several authors have assessed the effects of seawater salinity shifts and pH decrease on marine bivalves, but most of these studies evaluated the impacts of both factors independently. Since pH and salinity may act together in the environment, and their impacts may differ from their effects when acting alone, there is an urgent need to increase our knowledge when these environmental changes act in combination. Thus, the present study assessed the effects of seawater acidification and salinity changes, both acting alone and in combination, on the physiological (condition index, Na and K concentrations) and biochemical (oxidative stress related biomarkers) performance of Ruditapes philippinarum. For that, specimens of R. philippinarum were exposed for 28days to the combination of different pH levels (7.8 and 7.3) and salinities (14, 28 and 35). The results obtained showed that under control pH (7.8) and low salinity (14) the physiological status and biochemical performance of clams was negatively affected, revealing oxidative stress. However, under the same pH and at salinities 28 and 35 clams were able to maintain/regulate their physiological status and biochemical performance. Moreover, our findings showed that clams under low pH (7.3) and different salinities were able to maintain their physiological status and biochemical performance, suggesting that the low pH tested may mask the negative effects of salinity. Our results further demonstrated that, in general, at each salinity, similar physiological and biochemical responses were found in clams under both tested pH levels. Also, individuals under low pH (salinities 14, 28 and 25) and exposed to pH 7.8 and salinity 28 (control) tend to present a similar response pattern. These

  6. Environmental Controls and Life Support System (ECLSS) Design for a Space Exploration Vehicle (SEV)

    NASA Technical Reports Server (NTRS)

    Stambaugh, Imelda; Sankaran, Subra

    2010-01-01

    Engineers at Johnson Space Center (JSC) are developing an Environmental Control and Life Support System (ECLSS) design for the Space Exploration Vehicle (SEV). The SEV will aid to expand the human exploration envelope for Geostationary Transfer Orbit (GEO), Near Earth Object (NEO), or planetary missions by using pressurized surface exploration vehicles. The SEV, formerly known as the Lunar Electric Rover (LER), will be an evolutionary design starting as a ground test prototype where technologies for various systems will be tested and evolve into a flight vehicle. This paper will discuss the current SEV ECLSS design, any work contributed toward the development of the ECLSS design, and the plan to advance the ECLSS design based on the SEV vehicle and system needs.

  7. Ground Vehicle Convoying

    NASA Astrophysics Data System (ADS)

    Gage, Douglas W.; Pletta, J. Bryan

    1987-01-01

    Initial investigations into two different approaches for applying autonomous ground vehicle technology to the vehicle convoying application are described. A minimal capability system that would maintain desired speed and vehicle spacing while a human driver provided steering control could improve convoy performance and provide positive control at night and in inclement weather, but would not reduce driver manpower requirements. Such a system could be implemented in a modular and relatively low cost manner. A more capable system would eliminate the human driver in following vehicles and reduce manpower requirements for the transportation of supplies. This technology could also be used to aid in the deployment of teleoperated vehicles in a battlefield environment. The needs, requirements, and several proposed solutions for such an Attachable Robotic Convoy Capability (ARCC) system will be discussed. Included are discussions of sensors, communications, computers, control systems and safety issues. This advanced robotic convoy system will provide a much greater capability, but will be more difficult and expensive to implement.

  8. A Hierarchical Model Predictive Tracking Control for Independent Four-Wheel Driving/Steering Vehicles with Coaxial Steering Mechanism

    NASA Astrophysics Data System (ADS)

    Itoh, Masato; Hagimori, Yuki; Nonaka, Kenichiro; Sekiguchi, Kazuma

    2016-09-01

    In this study, we apply a hierarchical model predictive control to omni-directional mobile vehicle, and improve the tracking performance. We deal with an independent four-wheel driving/steering vehicle (IFWDS) equipped with four coaxial steering mechanisms (CSM). The coaxial steering mechanism is a special one composed of two steering joints on the same axis. In our previous study with respect to IFWDS with ideal steering, we proposed a model predictive tracking control. However, this method did not consider constraints of the coaxial steering mechanism which causes delay of steering. We also proposed a model predictive steering control considering constraints of this mechanism. In this study, we propose a hierarchical system combining above two control methods for IFWDS. An upper controller, which deals with vehicle kinematics, runs a model predictive tracking control, and a lower controller, which considers constraints of coaxial steering mechanism, runs a model predictive steering control which tracks the predicted steering angle optimized an upper controller. We verify the superiority of this method by comparing this method with the previous method.

  9. Flight Control Laws for NASA's Hyper-X Research Vehicle

    NASA Technical Reports Server (NTRS)

    Davidson, J.; Lallman, F.; McMinn, J. D.; Martin, J.; Pahle, J.; Stephenson, M.; Selmon, J.; Bose, D.

    1999-01-01

    The goal of the Hyper-X program is to demonstrate and validate technology for design and performance predictions of hypersonic aircraft with an airframe-integrated supersonic-combustion ramjet propulsion system. Accomplishing this goal requires flight demonstration of a hydrogen-fueled scramjet powered hypersonic aircraft. A key enabling technology for this flight demonstration is flight controls. Closed-loop flight control is required to enable a successful stage separation, to achieve and maintain the design condition during the engine test, and to provide a controlled descent. Before the contract award, NASA developed preliminary flight control laws for the Hyper-X to evaluate the feasibility of the proposed scramjet test sequence and descent trajectory. After the contract award, a Boeing/NASA partnership worked to develop the current control laws. This paper presents a description of the Hyper-X Research Vehicle control law architectures with performance and robustness analyses. Assessments of simulated flight trajectories and stability margin analyses demonstrate that these control laws meet the flight test requirements.

  10. Trajectory Control for Vehicles Entering the Earth's Atmosphere at Small Flight Path Angles

    NASA Technical Reports Server (NTRS)

    Eggleston, John M.

    1959-01-01

    Methods of controlling the trajectories of high-drag-low-lift vehicles entering the earth's atmosphere at angles of attack near 90 deg and at initial entry angles up to 3 deg are studied. The trajectories are calculated for vehicles whose angle of attack can be held constant at some specified value or can be perfectly controlled as a function of some measured quantity along the trajectory. The results might be applied in the design of automatic control systems or in the design of instruments which will give the human pilot sufficient information to control his trajectory properly during an atmospheric entry. Trajectory data are compared on the basis of the deceleration, range, angle of attack, and, in some cases, the rate of descent. The aerodynamic heat-transfer rate and skin temperature of a vehicle with a simple heat-sink type of structure are calculated for trajectories made with several types of control functions. For the range of entry angles considered, it is found that the angle of attack can be controlled to restrict the deceleration down to an arbitrarily chosen level of 3g. All the control functions tried are successful in reducing the maximum deceleration to the desired level. However, in order to avoid a tendency for the deceleration to reach an initial peak decrease, and then reach a second peak, some anticipation is required in the control function so that the change in angle of attack will lead the change in deceleration. When the angle of attack is controlled in the aforementioned manner, the maximum rate of aerodynamic heat transfer to the skin is reduced, the maximum skin temperature of the vehicle is virtually unaffected, and the total heat absorbed is slightly increased. The increase in total heat can be minimized, however, by maintaining the maximum desired deceleration for as much of the trajectory as possible. From an initial angle of attack of 90 deg, the angle-of-attack requirements necessary to maintain constant values of deceleration (1g

  11. Digital control of a direct current converter for a hybrid vehicle

    NASA Astrophysics Data System (ADS)

    Hernandez, Juan Manuel

    The nonlinear feedback loops permitting the large signal control of pulse width modulators in direct current converters are discussed. A digital feedback loop on a converter controlling the coupling of a direct current machine is described. It is used in the propulsion of a hybrid vehicle (thermal-electric) with regenerative braking. The protection of the power switches is also studied. An active protection of the MOST bipolar transistor association is proposed.

  12. Preoperative hydration with 0.9% normal saline to prevent acute kidney injury after major elective open abdominal surgery: A randomised controlled trial.

    PubMed

    Serrano, Ana B; Candela-Toha, Angel M; Zamora, Javier; Vera, Jorge; Muriel, Alfonso; Del Rey, Jose M; Liaño, Fernando

    2016-06-01

    Postoperative acute kidney injury (AKI) is the second leading cause of hospital-acquired AKI. Although many preventive strategies have been tested, none of them has been totally effective. We investigated whether preoperative intravenous hydration with 0.9% normal saline could prevent postoperative AKI. Randomised controlled trial. University Ramón y Cajal Hospital, Spain, from June 2006 to February 2011. Total 328 inpatients scheduled for major elective open abdominal surgery. 0.9% normal saline at a dose of 1.5 ml kg h for 12 h before surgery. The primary outcome was the overall postoperative AKI incidence during the first week after surgery defined by risk, injury, failure, loss, end-stage kidney disease (RIFLE) and AKI network (AKIN) creatinine criteria. Secondary endpoints were the need for ICU admission, renal replacement therapy during the study period and adverse events and hospital mortality during hospital admission. There was no difference in the incidence of AKI between groups: 4.7% in the normal saline group versus 5.0% in the control group and 11.4% in the 0.9% normal saline group versus 7.9% in the control group as assessed by the RIFLE and AKIN creatinine criteria, respectively. Absolute risk reductions (95% confidence interval) were -0.3% (-5.3 to 4.7%) for RIFLE and 3.5% (-10.2 to 3.6%) for AKIN. ICU admission after surgery was required in 44.5% of all participants. Only 2 (0.7%) patients required renal replacement therapy during the first week after surgery. The analysis of adverse events did not show statistically significant differences between the groups except for pain. In our population, 8 (2.4%) patients died during their hospital admission. Intravenous hydration with 0.9% normal saline before major open abdominal surgery was not effective in preventing postoperative AKI. No safety concerns were identified during the trial. Clinical trials.gov: NCT00953940 and EUDRA CT: 2005-004755-35.

  13. A Morphing Radiator for High-Turndown Thermal Control of Crewed Space Exploration Vehicles

    NASA Technical Reports Server (NTRS)

    Cognata, Thomas J.; Hardtl, Darren; Sheth, Rubik; Dinsmore, Craig

    2015-01-01

    Spacecraft designed for missions beyond low earth orbit (LEO) face a difficult thermal control challenge, particularly in the case of crewed vehicles where the thermal control system (TCS) must maintain a relatively constant internal environment temperature despite a vastly varying external thermal environment and despite heat rejection needs that are contrary to the potential of the environment. A thermal control system is in other words required to reject a higher heat load to warm environments and a lower heat load to cold environments, necessitating a quite high turndown ratio. A modern thermal control system is capable of a turndown ratio of on the order of 12:1, but for crew safety and environment compatibility these are massive multi-loop fluid systems. This paper discusses the analysis of a unique radiator design which employs the behavior of shape memory alloys (SMA) to vary the turndown of, and thus enable, a single-loop vehicle thermal control system for space exploration vehicles. This design, a morphing radiator, varies its shape in response to facesheet temperature to control view of space and primary surface emissivity. Because temperature dependence is inherent to SMA behavior, the design requires no accommodation for control, instrumentation, nor power supply in order to operate. Thermal and radiation modeling of the morphing radiator predict a turndown ranging from 11.9:1 to 35:1 independent of TCS configuration. Stress and deformation analyses predict the desired morphing behavior of the concept. A system level mass analysis shows that by enabling a single loop architecture this design could reduce the TCS mass by between 139 kg and 225 kg. The concept is demonstrated in proof-of-concept benchtop tests.

  14. Design of Launch Vehicle Flight Control Augmentors and Resulting Flight Stability and Control (Center Director's Discretionary Fund Project 93-05, Part III)

    NASA Technical Reports Server (NTRS)

    Barret, C.

    1997-01-01

    This publication presents the control requirements, the details of the designed Flight Control Augmentor's (FCA's), the static stability and dynamic stability wind tunnel test programs, the static stability and control analyses, the dynamic stability characteristics of the experimental Launch Vehicle (LV) with the designed FCA's, and a consideration of the elastic vehicle. Dramatic improvements in flight stability have been realized with all the FCA designs; these ranged from 41 percent to 72 percent achieved by the blunt TE design. The control analysis showed that control increased 110 percent with only 3 degrees of FCA deflection. The dynamic stability results showed improvements with all FCA designs tested at all Mach numbers tested. The blunt TE FCA's had the best overall dynamic stability results. Since the lowest elastic vehicle frequency must be well separated from that of the control system, the significant frequencies and modes of vibration have been identified, and the response spectra compared for the experimental LV in both the conventional and the aft cg configuration. Although the dynamic response was 150 percent greater in the aft cg configuration, the lowest bending mode frequency decreased by only 2.8 percent.

  15. Automated space vehicle control for rendezvous proximity operations

    NASA Technical Reports Server (NTRS)

    Lea, Robert N.

    1988-01-01

    Rendezvous during the unmanned space exploration missions, such as a Mars Rover/Sample Return will require a completely automatic system from liftoff to docking. A conceptual design of an automated rendezvous, proximity operations, and docking system is being implemented and validated at the Johnson Space Center (JSC). The emphasis is on the progress of the development and testing of a prototype system for control of the rendezvous vehicle during proximity operations that is currently being developed at JSC. Fuzzy sets are used to model the human capability of common sense reasoning in decision making tasks and such models are integrated with the expert systems and engineering control system technology to create a system that performs comparably to a manned system.

  16. Automated space vehicle control for rendezvous proximity operations

    NASA Technical Reports Server (NTRS)

    Lea, Robert N.

    1988-01-01

    Rendezvous during the unmanned space exploration missions, such as a Mars Rover/Sample Return will require a completely automatic system from liftoff to docking. A conceptual design of an automated rendezvous, proximity operations, and docking system is being implemented and validated at the Johnson Space Center (JSC). The emphasis is on the progress of the development and testing of a prototype system for control of the rendezvous vehicle during proximity operations that is currently being developed at JSC. Fuzzy sets are used to model the human capability of common sense reasoning in decision-making tasks and such models are integrated with the expert systems and engineering control system technology to create a system that performs comparably to a manned system.

  17. Space vehicle electrical power processing distribution and control study. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    Krausz, A.

    1972-01-01

    A concept for the processing, distribution, and control of electric power for manned space vehicles and future aircraft is presented. Emphasis is placed on the requirements of the space station and space shuttle configurations. The systems involved are referred to as the processing distribution and control system (PDCS), electrical power system (EPS), and electric power generation system (EPGS).

  18. Orion Crew Exploration Vehicle Launch Abort System Guidance and Control Analysis Overview

    NASA Technical Reports Server (NTRS)

    Davidson, John B.; Kim, Sungwan; Raney, David L.; Aubuchon, Vanessa V.; Sparks, Dean W.; Busan, Ronald C.; Proud, Ryan W.; Merritt, Deborah S.

    2008-01-01

    Aborts during the critical ascent flight phase require the design and operation of Orion Crew Exploration Vehicle (CEV) systems to escape from the Crew Launch Vehicle (CLV) and return the crew safely to the Earth. To accomplish this requirement of continuous abort coverage, CEV ascent abort modes are being designed and analyzed to accommodate the velocity, altitude, atmospheric, and vehicle configuration changes that occur during ascent. Aborts from the launch pad to early in the flight of the CLV second stage are performed using the Launch Abort System (LAS). During this type of abort, the LAS Abort Motor is used to pull the Crew Module (CM) safely away from the CLV and Service Module (SM). LAS abort guidance and control studies and design trades are being conducted so that more informed decisions can be made regarding the vehicle abort requirements, design, and operation. This paper presents an overview of the Orion CEV, an overview of the LAS ascent abort mode, and a summary of key LAS abort analysis methods and results.

  19. Emissions and Cost Implications of Controlled Electric Vehicle Charging in the U.S. PJM Interconnection.

    PubMed

    Weis, Allison; Michalek, Jeremy J; Jaramillo, Paulina; Lueken, Roger

    2015-05-05

    We develop a unit commitment and economic dispatch model to estimate the operation costs and the air emissions externality costs attributable to new electric vehicle electricity demand under controlled vs uncontrolled charging schemes. We focus our analysis on the PJM Interconnection and use scenarios that characterize (1) the most recent power plant fleet for which sufficient data are available, (2) a hypothetical 2018 power plant fleet that reflects upcoming plant retirements, and (3) the 2018 fleet with increased wind capacity. We find that controlled electric vehicle charging can reduce associated generation costs by 23%-34% in part by shifting loads to lower-cost, higher-emitting coal plants. This shift results in increased externality costs of health and environmental damages from increased air pollution. On balance, we find that controlled charging of electric vehicles produces negative net social benefits in the recent PJM grid but could have positive net social benefits in a future grid with sufficient coal retirements and wind penetration.

  20. Vehicle Characteristics

    DTIC Science & Technology

    2008-02-14

    g. Material. 5.1.7 Wheel Geometry. a. Camber angle. b. Caster angle. c. Pivot angle. d. Static toe-in. e. Turning angles...the vehicle characteristics to be obtained during testing of wheeled and tracked vehicles and their components. Physical characterization of test...frontal area Characteristic data sheet Power train Suspention Wheel geometry Vehicle clearance angles Armament Gun control systems 16. SECURITY