Science.gov

Sample records for adaptive suspension vehicle

  1. Machines that walk: The adaptive suspension vehicle

    NASA Astrophysics Data System (ADS)

    Song, Shin-Min; Waldron, Kenneth J.

    The design and operation of statically stable fully terrain-adaptive walking machines are discussed, with an emphasis on the adaptive-suspension vehicle developed at Ohio State University (Waldron and McGhee, 1986). Chapters are devoted to a review of walking-machine development, gait analysis and gaits for level walking, gaits for irregular terrain, coordination, leg design by four-bar linkage synthesis, design of a pantograph leg, motion-controlled ankle design, and the Adaptive Suspension Vehicle. Diagrams, drawings, and graphs are provided.

  2. Guidance and Actuation Systems for an Adaptive-Suspension Vehicle

    DTIC Science & Technology

    1984-03-14

    FORM 1. REPORT NUMBER 2. GOVT ACCESSION NO. 3 . RECIPIENT’S CATALOG NUMBER G8186-685-84 ’D Ji 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED...Adaptive-Suspension Vehicle ..... ........ 2 2.2.2 The Terrain-Sensing System ...... .......... 3 2.3 Guidance System Algorithms... 3 2.3.1 Overview ............. ................... 3 2.3.2 Elevation Map Algorithms ...... ........... 3 2.3.3 Vehicle Guidance Algorithms

  3. Vehicle suspension

    SciTech Connect

    Mikina, S.J.

    1986-08-05

    This patent describes a vehicle consisting of sprung and unsprung masses, the combination of struts and support springs for the weight of the sprung mass, an axis defined by pivots between sprung and unsprung masses, with a front pivot approximately midway between the wheels and near the vertical and horizontal planes through the front axles, with a rear pivot lying in an axis through the front pivot and in a plane through the center-of-gravity of the sprung mass, with the plane parallel to the centrifugal force vector through the center-of-gravity of the sprung mass, and with the rear pivot positioned approximately midway between the rear wheels, means for transmitting the centrifugal force component on the front pivot to the front wheels and ground, and means for transmitting the centrifugal force component on the rear pivot to the rear wheels and ground.

  4. A dynamic-reliable multiple model adaptive controller for active vehicle suspension under uncertainties

    NASA Astrophysics Data System (ADS)

    Zhong, X.; Ichchou, M.; Gillot, F.; Saidi, A.

    2010-04-01

    The inherent uncertainties of vehicle suspension systems challenge not only the capability of ride comfort and handling performance, but also the reliability requirement. In this research, a dynamic-reliable multiple model adaptive (MMA) controller is developed to overcome the difficulty of suspension uncertainties while considering performance and reliability at the same time. The MMA system consists of a finite number of optimal sub-controllers and employs a continuous-time based Markov chain to guide the jumping among the sub-controllers. The failure mode considered is the bottoming and topping of suspension components. A limitation on the failure probability is imposed to penalize the performance of the sub-controllers and a gradient-based genetic algorithm yields their optimal feedback gains. Finally, the dynamic reliability of the MMA controller is approximated by using the integration of state covariances and a judging condition is induced to assert that the MMA system is dynamic-reliable. In numerical simulation, a long scheme with piecewise time-invariant parameters is employed to examine the performance and reliability under the uncertainties of sprung mass, road condition and driving velocity. It is shown that the dynamic-reliable MMA controller is able to trade a small amount of model performance for extra reliability.

  5. Vehicle active suspension system using skyhook adaptive neuro active force control

    NASA Astrophysics Data System (ADS)

    Priyandoko, G.; Mailah, M.; Jamaluddin, H.

    2009-04-01

    This paper aims to highlight the practical viability of a new and novel hybrid control technique applied to a vehicle active suspension system of a quarter car model using skyhook and adaptive neuro active force control (SANAFC). The overall control system essentially comprises four feedback control loops, namely the innermost proportional-integral (PI) control loop for the force tracking of the pneumatic actuator, the intermediate skyhook and active force control (AFC) control loops for the compensation of the disturbances and the outermost proportional-integral-derivative (PID) control loop for the computation of the optimum target/commanded force. A neural network (NN) with a modified adaptive Levenberg-Marquardt learning algorithm was used to approximate the estimated mass and inverse dynamics of the pneumatic actuator in the AFC loop. A number of experiments were carried out on a physical test rig using a hardware-in-the-loop configuration that fully incorporates the theoretical elements. The performance of the proposed control method was evaluated and compared to examine the effectiveness of the system in suppressing the vibration effect on the suspension system. It was found that the simulation and experimental results were in good agreement, particularly for the sprung mass displacement and acceleration behaviours in which the proposed SANAFC scheme is found to outperform the PID and passive counterparts.

  6. Dual trailing arm vehicle suspension system

    SciTech Connect

    Weitzenhof, D.A.; Sayre, C.F.

    1986-11-18

    This patent describes a vehicle suspension system adapted to be interposed between a vehicle frame and at least two wheels arranged one in advance of the other on a side of the vehicle frame; the suspension system including: (a) at least two axles on a side of the vehicle frame for independently rotatably mounting each of the wheels; (b) at least two trailing arms, each of the arms being attached at one end to a respective axle and extending forwardly from the axle wherein the number of the trailing arms does not exceed the number of axles; (c) at least two pivot means mounted on the vehicle frame and connected to the other end of the trailing arms for pivotally mounting the vehicle frame wherein the number of the pivot means, does not exceed the number of axles; (d) lever means attached to and extending outwardly from each of the pivot means for pivotal movement with the pivot means means in relationship to movement of the trailing arms, with the length of the lever means being independent of the spacing between the axles; and (e) elastomer spring means extending between and pivotally mounted on the lever means for absorbing and balancing the forces exerted on the wheels particularly during braking and when encountering variations in the road surface.

  7. Four-Wheel Vehicle Suspension System

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.

    1990-01-01

    Four-wheel suspension system uses simple system of levers with no compliant components to provide three-point suspension of chassis of vehicle while maintaining four-point contact with uneven terrain. Provides stability against tipping of four-point rectangular base, without rocking contact to which rigid four-wheel frame susceptible. Similar to six-wheel suspension system described in "Articulated Suspension Without Springs" (NPO-17354).

  8. Hydraulically interconnected vehicle suspension: handling performance

    NASA Astrophysics Data System (ADS)

    Smith, Wade A.; Zhang, Nong; Hu, William

    2011-02-01

    This paper extends recent research on vehicles with hydraulically interconnected suspension (HIS) systems. Such suspension schemes have received considerable attention in the research community over the last few years. This is due, in part, to their reported ability to provide stiffness and damping rates dependent on the suspension mode of operation (i.e. the bounce, roll, pitch or articulation of the unsprung masses relative to the sprung mass), rather than relying on the stiffness and damping characteristics of the single wheel stations. The paper uses a nine-degrees-of-freedom (DOF) vehicle model and simulations of a fishhook manoeuvre to assess the handling performance of a vehicle when it is fitted with: (a) a conventional independent suspension, and (b) an HIS. In the case of the latter, the fluid subsystem is modelled using a nonlinear finite-element approach, resulting in a set of coupled, first-order nonlinear differential equations, which describe the dynamics of the integrated mechanical-hydraulic vehicle system. The simulation results indicate that, in general, the HIS-equipped vehicle possesses superior handling, as measured by the sprung mass roll angle, roll rate, roll acceleration, lateral acceleration and the vehicle's Rollover Critical Factor. The potential effects of the suspension set-up on ride performance are also considered by studying the transient response when one side of the vehicle traverses a half-sine bump. The obtained results are then discussed, and it is shown that they are consistent with previous findings, both by the authors and other researchers. The presented work outlines an alternative approach for studying the dynamics of HIS-equipped vehicles, particularly suited to analyses in the time domain.

  9. Hydraulically interconnected vehicle suspension: background and modelling

    NASA Astrophysics Data System (ADS)

    Zhang, Nong; Smith, Wade A.; Jeyakumaran, Jeku

    2010-01-01

    This paper presents a novel approach for the frequency domain analysis of a vehicle fitted with a general hydraulically interconnected suspension (HIS) system. Ideally, interconnected suspensions have the capability, unique among passive systems, to provide stiffness and damping characteristics dependent on the all-wheel suspension mode in operation. A basic, lumped-mass, four-degree-of-freedom half-car model is used to illustrate the proposed methodology. The mechanical-fluid boundary condition in the double-acting cylinders is modelled as an external force on the mechanical system and a moving boundary on the fluid system. The fluid system itself is modelled using the hydraulic impedance method, in which the relationships between the dynamic fluid states, i.e. pressures and flows, at the extremities of a single fluid circuit are determined by the transfer matrix method. A set of coupled, frequency-dependent equations, which govern the dynamics of the integrated half-car system, are then derived and the application of these equations to both free and forced vibration analysis is explained. The fluid system impedance matrix for the two general wheel-pair interconnection types-anti-synchronous and anti-oppositional-is also given. To further outline the application of the proposed methodology, the paper finishes with an example using a typical anti-roll HIS system. The integrated half-car system's free vibration solutions and frequency response functions are then obtained and discussed in some detail. The presented approach provides a scientific basis for investigating the dynamic characteristics of HIS-equipped vehicles, and the results offer further confirmation that interconnected suspension schemes can provide, at least to some extent, individual control of modal stiffness and damping characteristics.

  10. 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.

  11. A Constraint Embedding Approach for Complex Vehicle Suspension Dynamics

    DTIC Science & Technology

    2015-04-24

    Suspension Dynamics ECCOMAS Thematic Conference on Multibody Dynamics 2015 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...Complex Vehicle Suspension Dynamics ECCOMAS Thematic Conference on Multibody Dynamics 2015 Abhinandan Jain∗, Calvin Kuo#, Paramsothy Jayakumar†, Jonathan...topic of this paper is the de- velopment of computationally efficient and accurate dynamics model for ground vehicles with complex suspension dynamics. In

  12. Design of passive vehicle suspensions for maximal least damping ratio

    NASA Astrophysics Data System (ADS)

    Smith, Malcolm C.; Swift, Stuart J.

    2016-05-01

    This paper studies the use of the least damping ratio among system poles as a performance metric in passive vehicle suspensions. Methods are developed which allow optimal solutions to be computed in terms of non-dimensional quantities in a quarter-car vehicle model. Solutions are provided in graphical form for convenient use across vehicle types. Three suspension arrangements are studied: the standard suspension involving a parallel spring and damper and two further suspension arrangements involving an inerter. The key parameters for the optimal solutions are the ratios of unsprung mass to sprung mass and suspension static stiffness to tyre vertical stiffness. A discussion is provided of performance trends in terms of the key parameters. A comparison is made with the optimisation of ride comfort and tyre grip metrics for various vehicle types.

  13. Modeling of Semi-Active Vehicle Suspension with Magnetorhological Damper

    NASA Astrophysics Data System (ADS)

    Hasa, Richard; Danko, Ján; Milesich, Tomáš; Magdolen, Ľuboš

    2014-12-01

    Modeling of suspension is a current topic. Vehicle users require both greater driving comfort and safety. There is a space to invent new technologies like magnetorheological dampers and their control systems to increase these conflicting requirements. Magnetorheological dampers are reliably mathematically described by parametric and nonparametric models. Therefore they are able to reliably simulate the driving mode of the vehicle. These simulations are important for automotive engineers to increase vehicle safety and passenger comfort.

  14. Adaptive super-twisting observer for estimation of random road excitation profile in automotive suspension systems.

    PubMed

    Rath, J J; Veluvolu, K C; Defoort, M

    2014-01-01

    The estimation of road excitation profile is important for evaluation of vehicle stability and vehicle suspension performance for autonomous vehicle control systems. In this work, the nonlinear dynamics of the active automotive system that is excited by the unknown road excitation profile are considered for modeling. To address the issue of estimation of road profile, we develop an adaptive supertwisting observer for state and unknown road profile estimation. Under Lipschitz conditions for the nonlinear functions, the convergence of the estimation error is proven. Simulation results with Ford Fiesta MK2 demonstrate the effectiveness of the proposed observer for state and unknown input estimation for nonlinear active suspension system.

  15. Adaptive Super-Twisting Observer for Estimation of Random Road Excitation Profile in Automotive Suspension Systems

    PubMed Central

    Rath, J. J.; Veluvolu, K. C.; Defoort, M.

    2014-01-01

    The estimation of road excitation profile is important for evaluation of vehicle stability and vehicle suspension performance for autonomous vehicle control systems. In this work, the nonlinear dynamics of the active automotive system that is excited by the unknown road excitation profile are considered for modeling. To address the issue of estimation of road profile, we develop an adaptive supertwisting observer for state and unknown road profile estimation. Under Lipschitz conditions for the nonlinear functions, the convergence of the estimation error is proven. Simulation results with Ford Fiesta MK2 demonstrate the effectiveness of the proposed observer for state and unknown input estimation for nonlinear active suspension system. PMID:24683321

  16. Adaptive magnetorheological seat suspension for shock mitigation

    NASA Astrophysics Data System (ADS)

    Singh, Harinder J.; Wereley, Norman M.

    2013-04-01

    An adaptive magnetorheological seat suspension (AMSS) was analyzed for optimal protection of occupants from shock loads caused by the impact of a helicopter with the ground. The AMSS system consists of an adaptive linear stroke magnetorheological shock absorber (MRSA) integrated into the seat structure of a helicopter. The MRSA provides a large controllability yield force to accommodate a wide spectrum for shock mitigation. A multiple degrees-of-freedom nonlinear biodynamic model for a 50th percentile male occupant was integrated with the dynamics of MRSA and the governing equations of motion were investigated theoretically. The load-stroke profile of MRSA was optimized with the goal of minimizing the potential for injuries. The MRSA yield force and the shock absorber stroke limitations were the most crucial parameters for improved biodynamic response mitigation. An assessment of injuries based on established injury criteria for different body parts was carried out.

  17. Adaptive magnetorheological seat suspension for shock mitigation

    NASA Astrophysics Data System (ADS)

    Singh, Harinder Jit

    This research focuses on theoretical and experimental analysis of an adaptive seat suspension employing magnetorheological energy absorber with the objective of minimizing injury potential to seated occupant of different weights subjected to broader crash intensities. The research was segmented into three tasks: (1) development of magnetorheological energy absorber, (2) biodynamic modeling of a seated occupant, and (3) control schemes for shock mitigation. A linear stroking semi-active magnetorheological energy absorber (MREA) was designed, fabricated and tested for intense impact conditions with piston velocities up to 8 m/s. MREA design was optimized on the basis of Bingham-plastic model (BPM model) in order to maximize the energy absorption capabilities at high impact velocities. Computational fluid dynamics and magnetic FE analysis were conducted to validate MREA performance. Subsequently, low-speed cyclic testing (0-2 Hz subjected to 0-5.5 A) and high-speed drop testing (0-4.5 m/s at 0 A) were conducted for quantitative comparison with the numerical simulations. Later, a nonlinear four degrees-of-freedom biodynamic model representing a seated 50th percentile male occupant was developed on the basis of experiments conducted on Hybrid II 50th percentile male anthropomorphic test device. The response of proposed biodynamic model was compared quantitatively against two different biodynamic models from the literature that are heavily implemented for obtaining biodynamic response under impact conditions. The proposed biodynamic model accurately predicts peak magnitude, overall shape and the duration of the biodynamic transient response, with minimal phase shift. The biodynamic model was further validated against 16 impact tests conducted on horizontal accelerator facility at NAVAIR for two different shock intensities. Compliance effects of human body were also investigated on the performance of adaptive seat suspension by comparing the proposed biodynamic model

  18. Suspension Parameter Measurements of Wheeled Military Vehicles

    DTIC Science & Technology

    2012-08-01

    just behind the wheel location being tested, and a linear interpolation is made to estimate the motion of the vehicle body directly above the wheel...Military Vehicles, Andreatta, et al. Page 3 of 8 lateral (y) directions on linear rails with circulating balls. The effective coefficient of... friction of these rails is in the range of 0.002. Steer motion of the wheel pad is allowed by a large crossed roller bearing under the wheel pad. The

  19. Smart suspension systems for bridge-friendly vehicles

    NASA Astrophysics Data System (ADS)

    Chen, Yonghong; Tan, Chin An; Bergman, Larry A.; Tsao, T. C.

    2002-06-01

    In this paper, the effects of using semi-active control strategy (such as MR dampers) in vehicle suspensions on the coupled vibrations of a vehicle traversing a bridge are examined in order to develop various designs of smart suspension systems for bridge-friendly vehicles. The bridge-vehicle coupled system is modeled as a simply supported beam traversed by a two-degree-of-freedom quarter-car model. The surface unevenness on the bridge deck is modeled as a deterministic profile of a sinusoidal wave. As the vehicle travels along the bridge, the system is excited as a result of the surface unevenness and this excitation is characterized by a frequency defined by the speed of travel and the wavelength of the profile. The dynamic interactions between the bridge and the vehicle due to surface deck irregularities are obtained by solving the coupled equations of motion. Numerical results of a passive control strategy show that, when the lower natural frequency of the vehicle matches with a natural frequency (usually the first frequency) of the bridge and the excitation frequency, the maximum response of the bridge is large while the response of the vehicle is relatively smaller, meaning that the bridge behaves like a vibration absorber. This is undesirable from a bridge design viewpoint. Comparative studies of passive and semi-active controls for the vehicle suspension are performed. It is demonstrated that skyhook control can significantly mitigate the response of the bridge, while ground-hook control reduces the tire force impacted onto the bridge.

  20. Comparison of Performance Effectiveness of Linear Control Algorithms Developed for a Simplified Ground Vehicle Suspension System

    DTIC Science & Technology

    2011-04-01

    Comparison of Performance Effectiveness of Linear Control Algorithms Developed for a Simplified Ground Vehicle Suspension System by Ross... Linear Control Algorithms Developed for a Simplified Ground Vehicle Suspension System Ross Brown Motile Robotics, Inc, research contractor at U.S... Linear Control Algorithms Developed for a Simplified Ground Vehicle Suspension System 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

  1. Energy regenerative suspension test for EEV and hybrid vehicle

    NASA Astrophysics Data System (ADS)

    Abdullah, M. A.; Jamil, J. F.; Muhammad, N. S.

    2015-12-01

    The world is demanding on the alternative fuel and reducing the fuel consumption of land transportation especially in the automotive industries. This paper emphasizes the development of the energy regenerative suspension system (EReSS) for energy efficient vehicle (EEV) or hybrid. The EReSS product is fabricated and tested on the laboratory and real vehicle. The test is conducted to test the function of the EReSS system on real vehicle. The test is done using the multimeter to record the reading of voltage produces by the EReSS system that is attached to the vehicle suspension system. The experiment starts by setting the parameters in the EReSS system which is the number of windings with a standard magnet. Road irregularity is one of the important parts of the experiment which is set to be various types of road condition and driving style. A domestic car model is selected for the EReSS test that the system can be installed. The test of the EReSS gives out the maximum output voltage of 5.6 V with 530 windings. Improvement on the material can increase the output voltage. The EReSS is function on the real vehicle by producing voltage by harvesting the kinetic energy from the suspension vibration.

  2. 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.

  3. US Marine Corps assault amphibious vehicle suspension system analysis

    SciTech Connect

    Hammonds, C.J.; Jones, J.K.; Mayhall, J.A.; Williamson, D.E.

    1988-11-01

    In response to a request from the US Marine Corps (USMC), the Oak Ridge National Laboratory investigated a problem with the suspension system of the assault amphibious vehicle (AAV), Personnel Model 7A1. In the course of the investigation, drawings of the AAV and field survey data on bearing failures provided by VSE Corporation were used. The analysis approach taken was to model the suspension system and the vehicle hull and support structure using finite element techniques. This provided stress and deflection information for the system. To determine the loads imparted to the system as the AAV traversed terrain features, a dynamics model was developed to provide loads to the finite element analysis (FEA). Because the primary indication of a problem was frequent suspension-system bearing failure, an analysis of the suspension-system bearings was conducted. Finally, to check the accuracy of the models and to provide actual load data for bearing analysis, an instrumented AAV was tested over a surveyed course at Camp Pendleton, California. Initially the dynamics model assumed the interface between the hull and the suspension system to be fixed. Later improvements incorporating the flexibility of the vehicle hull into the analysis by linking the two models resulted in improved accuracy. Actual measurements of the front road-arm displacement and vertical acceleration of the chassis are compared with predictions from the model. The correlation is quite good and indicates that the model can accurately predict the dynamic load on each road wheel for input into finite element analyses. The dynamics model can be expanded to study the effects of adding weight to the vehicle, traversing other terrains, or evaluating inputs such as weapons firing or drop tests. 7 refs., 75 figs., 10 tabs.

  4. Multidisciplinary design optimization of mechatronic vehicles with active suspensions

    NASA Astrophysics Data System (ADS)

    He, Yuping; McPhee, John

    2005-05-01

    A multidisciplinary optimization method is applied to the design of mechatronic vehicles with active suspensions. The method is implemented in a GA-A'GEM-MATLAB simulation environment in such a way that the linear mechanical vehicle model is designed in a multibody dynamics software package, i.e. A'GEM, the controllers and estimators are constructed using linear quadratic Gaussian (LQG) method, and Kalman filter algorithm in Matlab, then the combined mechanical and control model is optimized simultaneously using a genetic algorithm (GA). The design variables include passive parameters and control parameters. In the numerical optimizations, both random and deterministic road inputs and both perfect measurement of full state variables and estimated limited state variables are considered. Optimization results show that the active suspension systems based on the multidisciplinary optimization method have better overall performance than those derived using conventional design methods with the LQG algorithm.

  5. Design and analysis of a shock absorber with variable moment of inertia for passive vehicle suspensions

    NASA Astrophysics Data System (ADS)

    Xu, Tongyi; Liang, Ming; Li, Chuan; Yang, Shuai

    2015-10-01

    A two-terminal mass (TTM) based vibration absorber with variable moment of inertia (VMI) for passive vehicle suspension is proposed. The VMI of the system is achieved by the motion of sliders embedded in a hydraulic driven flywheel. The moment of inertia increases in reaction to strong vertical vehicle oscillations and decreases for weak vertical oscillations. The hydraulic mechanism of the system converts the relative linear motion between the two terminals of the suspension into rotating motion of the flywheel. In the case of stronger vehicle vertical oscillation, the sliders inside the flywheel move away from the center of the flywheel because of the centrifugal force, hence yielding higher moment of inertia. The opposite is true in the case of weaker vehicle oscillation. As such, the moment of inertia adjusts itself adaptively in response to the road conditions. The performance of the proposed TTM-VMI absorber has been analyzed via dynamics modeling and simulation and further examined by experiments. In comparison to its counterpart with constant moment of inertia, the proposed VMI system offers faster response, better road handling and safety, improved ride comfort, and reduced suspension deflection except in the case of sinusoidal excitations.

  6. A hybrid electromagnetic shock absorber for active vehicle suspension systems

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Babak; Bolandhemmat, Hamidreza; Behrad Khamesee, Mir; Golnaraghi, Farid

    2011-02-01

    The use of electromagnetic dampers (ED) in vehicle active suspension systems has drawn considerable attention in the past few years, attributed to the fact that active suspension systems have shown superior performance in improving ride comfort and road handling of terrain vehicles, compared with their passive and semi-active counterparts. Although demonstrating superb performance, active suspensions still have some shortcomings that must be overcome. They have high energy consumption, weight, and cost and are not fail-safe in case of a power breakdown. The novel hybrid ED, which is proposed in this paper, is a potential solution to the above-mentioned drawbacks of conventional active suspension systems. The proposed hybrid ED is designed to inherit the high-performance characteristics of an active ED with the reliability of a passive damper in a single package. The eddy current damping effect is utilised as a source of the passive damping. First, a prototype ED is designed and fabricated. The prototype ED is then utilised to experimentally establish the design requirements for a real-size active ED. This is accomplished by comparing its vibration isolation performance in a 1-DOF quarter-car test rig with that of a same-class semi-active damper. Then, after a real-size active ED is designed, the concept of hybrid damper is introduced to the damper design to address the drawbacks of the active ED. Finally, the finite-element method is used to accurately model and analyse the designed hybrid damper. It is demonstrated that by introducing the eddy current damping effect to the active part, a passive damping of approximately 1570 Ns/m is achieved. This amount of passive damping guarantees that the damper is fail-safe and reduces the power consumption more than 70%, compared with an active ED in an automotive active suspension system.

  7. Actively controlled vehicle suspension with energy regeneration capabilities

    NASA Astrophysics Data System (ADS)

    Bar David, Sagiv; Zion Bobrovsky, Ben

    2011-06-01

    The paper presents an innovative dual purpose automotive suspension topology, combining for the first time the active damping qualities with mechanical vibrations power regeneration capabilities. The new configuration consists of a linear generator as an actuator, a power processing stage based on a gyrator operating under sliding mode control and dynamics controllers. The researched design is simple and energetically efficient, enables an accurate force-velocity suspension characteristic control as well as energy regeneration control, with no practical implementation constraints imposed over the theoretical design. Active damping is based on Skyhook suspension control scheme, which enables overcoming the passive damping tradeoff between high- and low-frequency performance, improving both body isolation and the tire's road grip. The system-level design includes configuration of three system operation modes: passive, semi-active or fully active damping, all using the same electro-mechanical infrastructure, and each focusing on different objective: dynamics improvement or power regeneration. Conclusively, the innovative hybrid suspension is theoretically researched, practically designed and analysed, and proven to be feasible as well as profitable in the aspects of power regeneration, vehicle dynamics improvement and human health risks reduction.

  8. Magnetorheological impact seat suspensions for ground vehicle crash mitigation

    NASA Astrophysics Data System (ADS)

    Bai, Xian-Xu; Wereley, Norman M.

    2014-04-01

    Semi-active magnetorheological energy absorbers (MREAs) are one type of the most promising actuator for both the vibration and shock control. This paper investigates the frontal crash mitigation performance of semi-active MR impact seat suspensions for ground vehicles. The characteristics of two MREAs, a conventional MREA and an MREA with an internal bypass, with an identical volume, are theoretically evaluated and compared. To explore the control effectiveness of MREAs in the shock control systems, the mechanical model of a 4-degree-of-freedom (4DOF) sliding seat suspension system with MREAs is constructed. An optimal Bingham number control, which is to minimize the crash pulse loads transmitted to occupants by utilizing maximum stroke of the MREAs based on initial velocity of crash pulse, mass, and damping, is proposed and developed to improve the crash mitigation performance of the 4DOF MR sliding seat suspension control systems. The simulated control performances of the mitigation systems based on the MREAs with different functional structures are evaluated, compared, and analyzed. The research results indicate that (1) the constant stroking load velocity range of the MREAs is of significance to evaluate the controllability of the MREAs (i.e., the effectiveness of the semi-active shock control systems), and (2) suboptimal Bingham number control cannot realize "soft landing" (i.e., either an end-stop impact or incomplete utilization of the MREA stroke happens).

  9. Controlling the magnetorheological suspension of a vehicle seat including the biomechanics of the driver

    NASA Astrophysics Data System (ADS)

    Gągorowski, Andrzej

    2012-06-01

    This paper presents an original approach to the problem of controlling a magnetorheological suspension of a driver's seat for optimal reduction of whole-body vibration. The concept consists in taking into consideration the individual personal features (biomechanical parameters) of the driver in the control process of a MR damper by using human generated signals. The proposed algorithm enables the adaptation of the suspension for an individual driver and specific road conditions. The actual research has focused on numerical simulations with a complex model of the human-seat-vehicle system. The human model representing a specific driver has been described by several biomechanical parameters such as masses of body structures, moments of inertia, and stiffness and damping of the spine, intervertebral discs, spinal muscles and ligaments.

  10. Improving crosswind stability of fast rail vehicles using active secondary suspension

    NASA Astrophysics Data System (ADS)

    Thomas, Dirk; Berg, Mats; Persson, Rickard; Stichel, Sebastian

    2014-07-01

    Rail vehicles are today increasingly equipped with active suspension systems for ride comfort purposes. In this paper, it is studied whether these often powerful systems also can be used to improve crosswind stability. A fast rail vehicle equipped with active secondary suspension for ride comfort purposes is exposed to crosswind loads during curve negotiation. For high crosswind loads, the active secondary suspension is used to reduce the impact of crosswind on the vehicle. The control input is taken from the primary vertical suspension deflection. Three different control cases are studied and compared with the only comfort-oriented active secondary suspension and a passive secondary suspension. The application of active secondary suspension resulted in significantly improved crosswind stability.

  11. Analysis of Semi-Active and Passive Suspensions System for Off-Road Vehicles

    NASA Astrophysics Data System (ADS)

    BenLahcene, Zohir; Faris, Waleed F.; Khan, M. D. Raisuddin

    2009-03-01

    The speed of off-road vehicles over rough terrain is generally determined by the ride quality not by the engine power. For this reason, researches are currently being undertaking to improve the ride dynamics of these vehicles using an advanced suspension system. This study intends to provide a preliminary evaluation of whether semi-active suspensions are beneficial to improving ride and handling in off-road vehicles. One of the greatest challenges in designing off-road vehicle suspension system is maintaining a good balance between vehicle ride and handling. Three configurations of these vehicles; 2-axle, 3-xle and 4-axles have been studied and their performances are compared. The application of several control policies of semi-active suspension system, namely skyhook; ground-hook and hybrid controls have been analyzed and compared with passive systems. The results show that the hybrid control policy yields better comfort than a passive suspension, without reducing the road-holding quality or increasing the suspension displacement. The hybrid control policy is also shown to be a better compromise between comfort, road-holding and suspension displacement than the skyhook and ground-hook control policies. Results show an improvement in ride comfort and vehicle handling using 4-axle over 3-axle and 2-axle when emphasis is placed on the response of the vehicle body acceleration, suspension and tyre deflection.

  12. 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.

  13. Improved design of dynamic vibration absorber by using the inerter and its application in vehicle suspension

    NASA Astrophysics Data System (ADS)

    Shen, Yujie; Chen, Long; Yang, Xiaofeng; Shi, Dehua; Yang, Jun

    2016-01-01

    Inerter is a recently proposed mechanical element with two terminals. The novelty of this paper is to present the improved design which aims to add traditional dynamic vibration absorber to the vehicle body by using the inerter. Based on this background, a new vehicle suspension structure called ISD suspension, including the inerter, spring and damper has been created. A dual-mass vibration model including the ISD suspension is considered in this study. Parameters are obtained by using the genetic optimizing algorithm. The frequency-domain simulation confirms that the ISD suspension can effectively improve the damping performance of the suspension system, especially at the offset frequency of the vehicle body, which is consistent with the feature of the dynamic vibration absorber added to the vehicle body mass. At last, a prototype ball screw inerter has been designed and the bench test of a quarter-car model has been undertaken. Under the conditions of the random road input, the vehicle ride comfort evaluation of body acceleration RMS value decreases by 4% at most, the suspension deflection RMS value decreases by 16% at most, the tire dynamic load RMS value decreases by 6% at most. Power spectral density results also indicate that the ISD suspension has superior damping performance than passive suspension which proves that the proposed ISD suspension is deemed effective.

  14. 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.

  15. 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.

  16. Novel evaluation method of vehicle suspension performance based on concept of wheel turn center

    NASA Astrophysics Data System (ADS)

    Wang, Bo; Guan, Hsin; Lu, Pingping; Zhan, Jun

    2015-09-01

    The current research of suspension performance evaluation is mixed in the evaluation of vehicle handling and ride comfort. However, it is lack of a direct and independent evaluation method for suspension performance. In this paper, a novel wheel turn center method is proposed to evaluate the suspension performance. This method is based on the concept and application of wheel turn center (WTC) and sprung mass turn center (SPTC). The vehicle body and each wheel are regarded to be independent rigid bodies and have their own turn centers which reflect respective steering motions and responses. Since the suspension is the link between vehicle body and wheels, the consistence between the sprung mass turn center and the wheel turn center reflects the effect and performance of the suspension system. Firstly, the concept and appropriate calculation method of WTC and SPTC are developed. Then the degree of inconsistence between WTC and SPTC and the time that they achieve consistence, when the vehicle experiences from transient steering to steady steering state, are proposed to evaluate suspension performance. The suspension evaluation tests are conducted under different vehicle velocities and lateral accelerations by using CarSim software. The simulation results show that the inconsistence of steering motion between vehicle body and wheels are mainly at high speeds and low lateral accelerations. Finally, based on the proposed evaluation indexes, the influences of different suspension characteristic parameters on suspension performance and their matches to improve steering coordination are discussed. The proposed wheel turn center method provides a guidance and potential application for suspension evaluation and optimization.

  17. Dynamic response of a vehicle with planar suspension system (PSS) under differential braking

    NASA Astrophysics Data System (ADS)

    Zhu, Jian Jun; Khajepour, Amir; Esmailzadeh, Ebrahim

    2012-01-01

    To absorb the vibrations and shocks caused by road obstacles effectively in any direction within the wheel rotation plane, a planar suspension system (PSS), in which there are spring-damper struts in both the vertical and longitudinal directions, is proposed to improve the ride quality of a vehicle with such novel suspension systems. The longitudinal spring-damper strut in a PSS is considerably soft compared with the longitudinal connection in a conventional suspension. Consequently, the wheels in a vehicle with PSS can move forth and back with respect to the body. The dynamic behaviours of a PSS vehicle under some special conditions, such as a differential braking in which the braking torque applied to the wheels at two sides of an axle are uneven, may exhibit special characteristics. The directional stability of the PSS vehicle in such a case may be one of the major concerns. The dynamic performance of the PSS vehicle in the differential braking condition is thus necessary to be investigated. This paper presents the investigation results of the transient response of a vehicle with the PSS in such a case. The simulation results are also compared with those of a similar vehicle with conventional suspensions. The study demonstrates that the PSS vehicle is directionally stable in differential braking conditions. The dynamic behaviour of the PSS vehicle is generally comparable with that of a conventional vehicle.

  18. Adaptive control of an unmanned aerial vehicle

    NASA Astrophysics Data System (ADS)

    Nguen, V. F.; Putov, A. V.; Nguen, T. T.

    2017-01-01

    The paper deals with design and comparison of adaptive control systems based on plant state vector and output for unmanned aerial vehicle (UAV) with nonlinearity and uncertainty of parameters of the aircraft incomplete measurability of its state and presence of wind disturbances. The results of computer simulations of flight stabilization processes on the example of the experimental model UAV-70V (Aerospace Academy, Hanoi) with presence of periodic and non-periodic vertical wind disturbances with designed adaptive control systems based on plant state vector with state observer and plant output.

  19. Wheeled Vehicle Drive Lines, Axles, and Suspension Systems. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle drive lines, axles, and suspension systems. It provides the basic…

  20. Analysis of Rail Vehicle Suspension Spring with Special Emphasis on Curving, Tracking and Tractive Efforts

    NASA Astrophysics Data System (ADS)

    Kumbhalkar, M. A.; Bhope, D. V.; Vanalkar, A. V.

    2016-09-01

    The dynamics of the rail vehicle represents a balance between the forces acting between wheel and rail, the inertia forces and the forces exerted by suspension and articulation. Axial loading on helical spring causes vertical deflection at straight track but failures calls to investigate for lateral and longitudinal loading at horizontal and vertical curves respectively. Goods carrying vehicle has the frequent failures of middle axle inner suspension spring calls for investigation. The springs are analyzed for effect of stress concentration due to centripetal force and due to tractive and breaking effort. This paper also discusses shear failure analysis of spring at curvature and at uphill at various speeds for different loading condition analytically and by finite element analysis. Two mass rail vehicle suspension systems have been analyzed for vibration responses analytically using mathematical tool Matlab Simulink and the same will be evaluated using FFT vibration analyzer to find peak resonance in vertical, lateral and longitudinal direction. The results prove that the suspension acquires high repeated load in vertical and lateral direction due to tracking and curving causes maximum stress concentration on middle axle suspension spring as height of this spring is larger than end axle spring in primary suspension system and responsible for failure of middle axle suspension spring due to high stress acquisition.

  1. 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.

  2. Ride quality evaluation of a vehicle with a planar suspension system

    NASA Astrophysics Data System (ADS)

    Zhu, Jian Jun; Khajepour, Amir; Esmailzadeh, Ebrahim; Kasaiezadeh, Alireza

    2012-03-01

    The longitudinal connection between a chassis and a wheel in a conventional vehicle suspension system is commonly very stiff than the vertical connection. Such a mechanism can efficiently isolate vibrations and absorb shocks in the vertical direction but cannot sufficiently attenuate the impact in the longitudinal direction. In order to overcome such a limitation, a planar suspension system (PSS) with spring-damper struts in both the longitudinal and vertical directions is proposed so that the vibration along any direction in the wheel rotation plane can be isolated. In this paper, the dynamic responses of a vehicle with PSS due to a single bump and random road unevenness are investigated. The ride quality of the vehicle with PSS is evaluated in accordance with ISO 2631. A comparison with that of a similar conventional vehicle is conducted to demonstrate the promising potentials of the PSS in improving the vehicle ride quality.

  3. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, Donald M.; He, Jianliang; Johnson, Larry R.

    1994-01-01

    A propulsion and stabilization system comprising a series of FIG. 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the FIG. 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  4. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, D.M.; He, J.; Johnson, L.R.

    1994-01-04

    A propulsion and stabilization system are described comprising a series of coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance, and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension. 8 figures.

  5. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, D.M.; He, Jianliang; Johnson, L.R.

    1992-01-01

    This report discusses a propulsion and stabilization system comprising a series of figure 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the figure 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  6. Switched control of vehicle suspension based on motion-mode detection

    NASA Astrophysics Data System (ADS)

    Du, Haiping; Zhang, Nong; Wang, Lifu

    2014-01-01

    This paper presents a study on switched control of vehicle suspension based on motion-mode detection. This control strategy can be potentially implemented via the interconnected suspension such as hydraulically interconnected suspension by actively switching its interconnection configuration in terms of the dominant vehicle body motion-mode. The design of the switched control law is developed focusing on three vehicle body motion-modes: bounce, pitch, and roll. At first, an H∞ optimal controller will be designed for each motion-mode with the use of a common quadratic Lyapunov function, which guarantees the stability of the switched system under arbitrary switching functions. Then, a motion-mode detection method based on the calculation of the motion-mode energy is introduced. And then, the possible implementation of the control system in practice is discussed. Finally, numerical simulations are used to validate the proposed study.

  7. Adaptations to unilateral lower limb suspension in humans

    NASA Technical Reports Server (NTRS)

    Dudley, Gary A.; Duvoisin, Marc R.; Adams, Gregory R.; Meyer, Ronald A.; Belew, Anne H.; Buchanan, Paul

    1992-01-01

    The effect of unilateral lower limb suspension (ULLS) on neuromuscular function in humans is analyzed. All ambulatory activity on crutches was performed by eight subjects for 6 weeks who wear a shoe with a 10 cm sole on the right foot to unweight the left lower limb. Results show that average muscle cross sectional area (CSA) of the left knee extensor (KE) decreased 16 percent whereas the KE of the nonsuspended right limb showed no changes. Maximal integrated electromyography of vastus lateralis and overall mean power frequency of gastrocnemius medialis and soleus for submaximal isometric actions were both decreased post-ULLS. It is concluded that six weeks of ULLS induces adaptations in the neuromuscular system of humans which are comparable to those induced by bed rest and spaceflight.

  8. Skyhook-based semi-active control of full-vehicle suspension with magneto-rheological dampers

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    The control study of vehicle semi-active suspension with magneto-rheological (MR) dampers has been attracted much attention internationally. However, a simple, real time and easy implementing semi-active controller has not been proposed for the MR full-vehicle suspension system, and a systematic analysis method has not been established for evaluating the multi-objective suspension performances of MR full-vehicle vertical, pitch and roll motions. For this purpose, according to the 7-degree of freedom (DOF) full-vehicle dynamic system, a generalized 7-DOF MR and passive full-vehicle dynamic model is set up by employing the modified Bouc-wen hysteretic force-velocity ( F-v) model of the MR damper. A semi-active controller is synthesized to realize independent control of the four MR quarter-vehicle sub-suspension systems in the full-vehicle, which is on the basis of the proposed modified skyhook damping scheme of MR quarter-vehicle sub-suspension system. The proposed controller can greatly simplify the controller design complexity of MR full-vehicle suspension and has merits of easy implementation in real application, wherein only absolute velocities of sprung and unsprung masses with reference to the road surface are required to measure in real time when the vehicle is moving. Furthermore, a systematic analysis method is established for evaluating the vertical, pitch and roll motion properties of both MR and passive full-vehicle suspensions in a more realistic road excitation manner, in which the harmonic, rounded pulse and real road measured random signals with delay time are employed as different road excitations inserted on the front and rear two wheels, by considering the distance between front and rear wheels in full-vehicle. The above excitations with different amplitudes are further employed as the road excitations inserted on left and right two wheels for evaluating the roll motion property. The multi-objective suspension performances of ride comfort and

  9. Biochemical and histochemical adaptations of skeletal muscle to rat suspension

    NASA Technical Reports Server (NTRS)

    Templeton, G. H.

    1984-01-01

    The influence of rat suspension on soleus disuse and atrophy was investigated to measure changes in fiber area and number and to determine if suspension elicited changes in lysosomal protease activity and rate of calcium uptake by the sarcoplasmic reticulum. The infuence of rat suspension on myosin light chain phosphorylation and succinate dehydrogenase activity are determined.

  10. An efficient recursive least square-based condition monitoring approach for a rail vehicle suspension system

    NASA Astrophysics Data System (ADS)

    Liu, X. Y.; Alfi, S.; Bruni, S.

    2016-06-01

    A model-based condition monitoring strategy for the railway vehicle suspension is proposed in this paper. This approach is based on recursive least square (RLS) algorithm focusing on the deterministic 'input-output' model. RLS has Kalman filtering feature and is able to identify the unknown parameters from a noisy dynamic system by memorising the correlation properties of variables. The identification of suspension parameter is achieved by machine learning of the relationship between excitation and response in a vehicle dynamic system. A fault detection method for the vertical primary suspension is illustrated as an instance of this condition monitoring scheme. Simulation results from the rail vehicle dynamics software 'ADTreS' are utilised as 'virtual measurements' considering a trailer car of Italian ETR500 high-speed train. The field test data from an E464 locomotive are also employed to validate the feasibility of this strategy for the real application. Results of the parameter identification performed indicate that estimated suspension parameters are consistent or approximate with the reference values. These results provide the supporting evidence that this fault diagnosis technique is capable of paving the way for the future vehicle condition monitoring system.

  11. Modernisation of a test rig for determination of vehicle shock absorber characteristics by considering vehicle suspension elements and unsprung masses

    NASA Astrophysics Data System (ADS)

    Maniowski, M.; Para, S.; Knapczyk, M.

    2016-09-01

    This paper presents a modernization approach of a standard test bench for determination of damping characteristics of automotive shock absorbers. It is known that the real-life work conditions of wheel-suspension dampers are not easy to reproduce in laboratory conditions, for example considering a high frequency damper response or a noise emission. The proposed test bench consists of many elements from a real vehicle suspension. Namely, an original tyre-wheel with additional unsprung mass, a suspension spring, an elastic top mount, damper bushings and a simplified wheel guiding mechanism. Each component was tested separately in order to identify its mechanical characteristics. The measured data serve as input parameters for a numerical simulation of the test bench behaviour by using a vibratory model with 3 degrees of freedom. Study on the simulation results and the measurements are needed for further development of the proposed test bench.

  12. Design of a digital adaptive control system for reentry vehicles.

    NASA Technical Reports Server (NTRS)

    Picon-Jimenez, J. L.; Montgomery, R. C.; Grigsby, L. L.

    1972-01-01

    The flying qualities of atmospheric reentry vehicles experience considerable variations due to the wide changes in flight conditions characteristic of reentry trajectories. A digital adaptive control system has been designed to modify the vehicle's dynamic characteristics and to provide desired flying qualities for all flight conditions. This adaptive control system consists of a finite-memory identifier which determines the vehicle's unknown parameters, and a gain computer which calculates feedback gains to satisfy flying quality requirements.

  13. Analysis of Dynamic Stiffness Effect of Primary Suspension Helical Springs on Railway Vehicle Vibration

    NASA Astrophysics Data System (ADS)

    Sun, W.; Thompson, D. J.; Zhou, J.; Gong, D.

    2016-09-01

    Helical springs within the primary suspension are critical components for isolating the whole vehicle system from vibration generated at the wheel/rail contact. As train speeds increase, the frequency region of excitation becomes larger, and a simplified static stiffness can no longer represent the real stiffness property in a vehicle dynamic model. Coil springs in particular exhibit strong internal resonances, which lead to high vibration amplitudes within the spring itself as well as degradation of the vibration isolation. In this paper, the dynamic stiffness matrix method is used to determine the dynamic stiffness of a helical spring from a vehicle primary suspension. Results are confirmed with a finite element analysis. Then the spring dynamic stiffness is included within a vehicle-track coupled dynamic model of a high speed train and the effect of the dynamic stiffening of the spring on the vehicle vibration is investigated. It is shown that, for frequencies above about 50 Hz, the dynamic stiffness of the helical spring changes sharply. Due to this effect, the vibration transmissibility increases considerably which results in poor vibration isolation of the primary suspension. Introducing a rubber layer in series with the coil spring can attenuate this effect.

  14. The effect of spring pads in the secondary suspension of railway vehicles on bogie yaw resistance

    NASA Astrophysics Data System (ADS)

    Michálek, Tomáš; Zelenka, Jaromír

    2015-12-01

    This paper deals with properties of bogie yaw resistance of an electric locomotive with secondary suspension consisting of flexi-coil springs supplemented with tilting spring pads. Transversal stiffness of a sample of a spring/pad assembly was measured on a dynamic test stand of the University of Pardubice (Czech Republic) and the results were applied into a multi-body model of the locomotive created in the simulation tool 'SJKV'. On the basis of the simulation results, a detailed analysis of the bogie yaw resistance was performed in order to explain the effect in dynamic behaviour of the locomotive when the moment against bogie rotation (and therefore the distribution of guiding forces on individual wheels, as well) is influenced with the vehicle speed in a certain curve. Results of this analysis show that the application of suspension elements with strongly directionally dependent transversal stiffness into the secondary suspension can just lead to a dependency of the bogie yaw resistance on cant deficiency, i.e. on the vehicle speed in curve. This fact has wide consequences on the vehicle dynamics (especially on the guiding behaviour of the vehicle in curves) and it also points out that the current method of evaluation of the bogie yaw resistance according to relevant standards, which is related with assessment of the quasistatic safety of a railway vehicle against derailment, is not objective enough.

  15. The adaptive cruise control vehicles in the cellular automata model

    NASA Astrophysics Data System (ADS)

    Jiang, Rui; Wu, Qing-Song

    2006-11-01

    This Letter presented a cellular automata model where the adaptive cruise control vehicles are modelled. In this model, the constant time headway policy is adopted. The fundamental diagram is presented. The simulation results are in good agreement with the analytical ones. The mixture of ACC vehicles with manually driven vehicles is investigated. It is shown that with the introduction of ACC vehicles, the jam can be suppressed.

  16. Importance of Interaction between Integrin and Actin Cytoskeleton in Suspension Adaptation of CHO cells.

    PubMed

    Walther, Christa G; Whitfield, Robert; James, David C

    2016-04-01

    The biopharmaceutical production process relies upon mammalian cell technology where single cells proliferate in suspension in a chemically defined synthetic environment. This environment lacks exogenous growth factors, usually contributing to proliferation of fibroblastic cell types such as Chinese hamster ovary (CHO) cells. Use of CHO cells for production hence requires a lengthy 'adaptation' process to select clones capable of proliferation as single cells in suspension. The underlying molecular changes permitting proliferation in suspension are not known. Comparison of the non-suspension-adapted clone CHO-AD and a suspension-adapted propriety cell line CHO-SA by flow cytometric analysis revealed a highly variable bi-modal expression pattern for cell-to-cell contact proteins in contrast to the expression pattern seen for integrins. Those have a uni-modal expression on suspension and adherent cells. Integrins showed a conformation distinguished by regularly distributed clusters forming a sphere on the cell membrane of suspension-adapted cells. Actin cytoskeleton analysis revealed reorganisation from the typical fibrillar morphology found in adherent cells to an enforced spherical subcortical actin sheath in suspension cells. The uni-modal expression and specific clustering of integrins could be confirmed for CHO-S, another suspension cell line. Cytochalasin D treatment resulted in breakdown of the actin sheath and the sphere-like integrin conformation demonstrating the link between integrins and actin in suspension-adapted CHO cells. The data demonstrates the importance of signalling changes, leading to an integrin rearrangement on the cell surface, and the necessity of the reinforcement of the actin cytoskeleton for proliferation in suspension conditions.

  17. 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.

  18. Application of Adaptive Autopilot Designs for an Unmanned Aerial Vehicle

    NASA Technical Reports Server (NTRS)

    Shin, Yoonghyun; Calise, Anthony J.; Motter, Mark A.

    2005-01-01

    This paper summarizes the application of two adaptive approaches to autopilot design, and presents an evaluation and comparison of the two approaches in simulation for an unmanned aerial vehicle. One approach employs two-stage dynamic inversion and the other employs feedback dynamic inversions based on a command augmentation system. Both are augmented with neural network based adaptive elements. The approaches permit adaptation to both parametric uncertainty and unmodeled dynamics, and incorporate a method that permits adaptation during periods of control saturation. Simulation results for an FQM-117B radio controlled miniature aerial vehicle are presented to illustrate the performance of the neural network based adaptation.

  19. Vehicle Surveillance with a Generic, Adaptive, 3D Vehicle Model.

    PubMed

    Leotta, Matthew J; Mundy, Joseph L

    2011-07-01

    In automated surveillance, one is often interested in tracking road vehicles, measuring their shape in 3D world space, and determining vehicle classification. To address these tasks simultaneously, an effective approach is the constrained alignment of a prior model of 3D vehicle shape to images. Previous 3D vehicle models are either generic but overly simple or rigid and overly complex. Rigid models represent exactly one vehicle design, so a large collection is needed. A single generic model can deform to a wide variety of shapes, but those shapes have been far too primitive. This paper uses a generic 3D vehicle model that deforms to match a wide variety of passenger vehicles. It is adjustable in complexity between the two extremes. The model is aligned to images by predicting and matching image intensity edges. Novel algorithms are presented for fitting models to multiple still images and simultaneous tracking while estimating shape in video. Experiments compare the proposed model to simple generic models in accuracy and reliability of 3D shape recovery from images and tracking in video. Standard techniques for classification are also used to compare the models. The proposed model outperforms the existing simple models at each task.

  20. 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.

  1. 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.

  2. Multi-vehicle target selection for adaptive cruise control

    NASA Astrophysics Data System (ADS)

    Moon, Seungwuk; Kang, Hyoung-Jin; Yi, Kyongsu

    2010-11-01

    This paper presents a target selection strategy for adaptive cruise control (ACC) in multiple vehicle traffic situations. Since there are many vehicles in a real road and various transitions between the subject vehicle and the neighbouring vehicles occurred, it is important to establish a target selection and a control strategy for applying the ACC system to multiple vehicle traffic scenes in order to improve the driver acceptance and the vehicle safety. For this purpose, it is necessary to determine which neighbouring vehicle is an important target for the adaptive cruise control and prevention of collision depending on a driving situation. A primary target selection algorithm decides an in-lane target and provides the information to a longitudinal controller in order to drive a subject vehicle smoothly and to ensure safety in multi-vehicle traffic situations. The proposed selection algorithm consists of an in-lane target detection, a motion-based analysis and an integration process. The performance and safety benefits of a multi-vehicle ACC system with proposed target selection strategy are investigated via simulations using several driving scenarios. Simulation results show that the system response is smooth and safe even in multiple vehicle driving situations.

  3. Non-dimensionalised closed-form parametric analysis of semi-active vehicle suspensions using a quarter-car model

    NASA Astrophysics Data System (ADS)

    Ahmadian, Mehdi; Blanchard, Emmanuel

    2011-02-01

    This article provides a non-dimensionalised closed-form analysis of semi-active vehicle suspensions, using a quarter-car model. The derivation of the closed-form solutions for three indices that can be used for ride comfort, vehicle handling, and stability are presented based on non-dimensionalised suspension parameters. The behaviour of semi-active vehicle suspensions is evaluated using skyhook, groundhook, and hybrid control policies, and compared with passive suspensions. The relationship between vibration isolation, suspension deflection, and road holding is studied, using three performance indices based on the mean square of the sprung mass acceleration, rattle space, and tyre deflection, respectively. The results of the study indicate that the hybrid control policy yields significantly better comfort than a passive suspension, without reducing the road-holding quality or increasing the suspension displacement for typical passenger cars. The results also indicate that for typical passenger cars, the hybrid control policy results in a better compromise between comfort, road holding and suspension travel requirements than both the skyhook and groundhook control methods.

  4. Annoyance rate evaluation method on ride comfort of vehicle suspension system

    NASA Astrophysics Data System (ADS)

    Tang, Chuanyin; Zhang, Yimin; Zhao, Guangyao; Ma, Yan

    2014-03-01

    The existing researches of the evaluation method of ride comfort of vehicle mainly focus on the level of human feelings to vibration. The level of human feelings to vibration is influenced by many factors, however, the ride comfort according to the common principle of probability and statistics and simple binary logic is unable to reflect these uncertainties. The random fuzzy evaluation model from people subjective response to vibration is adopted in the paper, these uncertainties are analyzed from the angle of psychological physics. Discussing the traditional evaluation of ride comfort during vehicle vibration, a fuzzily random evaluation model on the basis of annoyance rate is proposed for the human body's subjective response to vibration, with relevant fuzzy membership function and probability distribution given. A half-car four degrees of freedom suspension vibration model is described, subject to irregular excitations from the road surface, with the aid of software Matlab/Simulink. A new kind of evaluation method for ride comfort of vehicles is proposed in the paper, i.e., the annoyance rate evaluation method. The genetic algorithm and neural network control theory are used to control the system. Simulation results are obtained, such as the comparison of comfort reaction to vibration environments between before and after control, relationship of annoyance rate to vibration frequency and weighted acceleration, based on ISO 2631/1(1982), ISO 2631-1(1997) and annoyance rate evaluation method, respectively. Simulated assessment results indicate that the proposed active suspension systems prove to be effective in the vibration isolation of the suspension system, and the subjective response of human being can be promoted from very uncomfortable to a little uncomfortable. Furthermore, the novel evaluation method based on annoyance rate can further estimate quantitatively the number of passengers who feel discomfort due to vibration. A new analysis method of vehicle

  5. Fault detection and isolation for a full-scale railway vehicle suspension with multiple Kalman filters

    NASA Astrophysics Data System (ADS)

    Jesussek, Mathias; Ellermann, Katrin

    2014-12-01

    Reliability and dependability in complex mechanical systems can be improved by fault detection and isolation (FDI) methods. These techniques are key elements for maintenance on demand, which could decrease service cost and time significantly. This paper addresses FDI for a railway vehicle: the mechanical model is described as a multibody system, which is excited randomly due to track irregularities. Various parameters, like masses, spring- and damper-characteristics, influence the dynamics of the vehicle. Often, the exact values of the parameters are unknown and might even change over time. Some of these changes are considered critical with respect to the operation of the system and they require immediate maintenance. The aim of this work is to detect faults in the suspension system of the vehicle. A Kalman filter is used in order to estimate the states. To detect and isolate faults the detection error is minimised with multiple Kalman filters. A full-scale train model with nonlinear wheel/rail contact serves as an example for the described techniques. Numerical results for different test cases are presented. The analysis shows that for the given system it is possible not only to detect a failure of the suspension system from the system's dynamic response, but also to distinguish clearly between different possible causes for the changes in the dynamical behaviour.

  6. 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.

  7. 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.

  8. Heparin promotes suspension adaptation process of CHO-TS28 cells by eliminating cell aggregation.

    PubMed

    Li, Ling; Qin, Jun; Feng, Qiang; Tang, Hao; Liu, Rong; Xu, Liqing; Chen, Zhinan

    2011-01-01

    While heparin has been shown to eliminate cell aggregation in suspension adaptations of insect and HEK293 cells for virus-based cell cultures, the role of heparin in long period serum-free suspension adaptation of the anchorage-dependent Chinese hamster ovary (CHO) cell lines remains inconclusive. In this paper, we explore the potential application of heparin in suspension adaptation of CHO cell line which produces an anti-human chimeric antibody cHAb18. Heparin showed a concentration-dependent inhibition of CHO-TS28 cell-to-cell adhesion, with a significant inhibitory effect occurring when the concentration exceeded 250 μg/ml (P < 0.001). Heparin also exhibited a cell aggregation elimination role at all concentrations (P < 0.001). Furthermore, heparin promoted cell growth and antibody secretion, with the highest cell density ((99.83 ± 12.21) × 10(4) cells/ml, P = 0.034) and maximum antibody yield ((9.46 ± 0.94) mg/l, P < 0.001) both occurring at 250 μg/ml heparin. When agitated, cell aggregates were effectively dispersed by 250 μg/ml heparin and a single-cell suspension culture process was promoted. In suspension adapted CHO-TS28 cells, cell growth rates and specific antibody productivity were maintained; while antigen-binding activity improved slightly. Together, our results show that heparin may promote suspension adaptation of anchorage-depended CHO cells by resisting cell aggregation without reducing cell growth, antibody secretion, and antigen-binding activity.

  9. Analysis of an off road 4WD vehicle's suspension system modification - Case study of aftermarket suspension lift and modification of wheel track size

    NASA Astrophysics Data System (ADS)

    Ross, J.; Hazrat, M. A.; Rasul, M. G.

    2016-07-01

    In this research, a four wheel drive (4WD) suspension of a vehicle has been modified by increasing the ride height to investigate stability and cornering potential of the vehicle through load transfer and variation of roll angle. Further investigation has been conducted to observe the characteristics which are deemed desirable for off road application but detrimental to the on road application. The Constant Radius Cornering Test (CRCT) was chosen as a base method for experimental investigation to observe the effect of the suspension modifications. The test was carried out by undertaking a known radius and cambered corner at a constant speed. For this test, the acceleration and gyroscopic data were measured to check and compare the accuracy of the analysis performed by OptimumDynamics model. The tests were conducted by means of negotiating the curve at the speed of 80 km/h and it was gradually achieved to allow a good consensus of the amount of body roll the vehicle experienced. Using a surveyor's wheel, the radius of the corner was estimated as 160 m and using the gyroscopic sensor, the corner camber was measured at 4 degrees. While comparing the experimental results with the simulation results, the experimental constraints led to higher values than those of the analytical results. The total load transfer reduced by 2.9% with the increased track size. It has been observed that the dynamic load transfer component is lesser than the standard suspension with the aftermarket suspension lift and the upgraded anti-roll bar (ARB). With the simulation of the fitment of the other modifications aimed to improve the characteristics of the raised vehicle, the vehicle showed a reduced tendency towards roll angle due to the stiffened anti-roll bar and the maximum increased wheel track demonstrated reduced lateral load transfer and body roll. Even with these modifications however, the decrease in load transfer is minimal in comparison to what was expected.

  10. Adaptive Modeling, Engineering Analysis and Design of Advanced Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek; Hsu, Su-Yuen; Mason, Brian H.; Hicks, Mike D.; Jones, William T.; Sleight, David W.; Chun, Julio; Spangler, Jan L.; Kamhawi, Hilmi; Dahl, Jorgen L.

    2006-01-01

    This paper describes initial progress towards the development and enhancement of a set of software tools for rapid adaptive modeling, and conceptual design of advanced aerospace vehicle concepts. With demanding structural and aerodynamic performance requirements, these high fidelity geometry based modeling tools are essential for rapid and accurate engineering analysis at the early concept development stage. This adaptive modeling tool was used for generating vehicle parametric geometry, outer mold line and detailed internal structural layout of wing, fuselage, skin, spars, ribs, control surfaces, frames, bulkheads, floors, etc., that facilitated rapid finite element analysis, sizing study and weight optimization. The high quality outer mold line enabled rapid aerodynamic analysis in order to provide reliable design data at critical flight conditions. Example application for structural design of a conventional aircraft and a high altitude long endurance vehicle configuration are presented. This work was performed under the Conceptual Design Shop sub-project within the Efficient Aerodynamic Shape and Integration project, under the former Vehicle Systems Program. The project objective was to design and assess unconventional atmospheric vehicle concepts efficiently and confidently. The implementation may also dramatically facilitate physics-based systems analysis for the NASA Fundamental Aeronautics Mission. In addition to providing technology for design and development of unconventional aircraft, the techniques for generation of accurate geometry and internal sub-structure and the automated interface with the high fidelity analysis codes could also be applied towards the design of vehicles for the NASA Exploration and Space Science Mission projects.

  11. Adaptive guidance for an aero-assisted boost vehicle

    NASA Technical Reports Server (NTRS)

    Pamadi, Bandu N.; Taylor, Lawrence W., Jr.; Price, Douglas B.

    1988-01-01

    An adaptive guidance system incorporating dynamic pressure constraint is studied for a single stage to low earth orbit (LEO) aero-assist booster with thrust gimbal angle as the control variable. To derive an adaptive guidance law, cubic spline functions are used to represent the ascent profile. The booster flight to LEO is divided into initial and terminal phases. In the initial phase, the ascent profile is continuously updated to maximize the performance of the boost vehicle enroute. A linear feedback control is used in the terminal phase to guide the aero-assisted booster onto the desired LEO. The computer simulation of the vehicle dynamics considers a rotating spherical earth, inverse square (Newtonian) gravity field and an exponential model for the earth's atmospheric density. This adaptive guidance algorithm is capable of handling large deviations in both atmospheric conditions and modeling uncertainties, while ensuring maximum booster performance.

  12. 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

  13. Influence of Flocculating Agents and Structural Vehicles on the Physical Stability and Rheological Behavior of Nitrofurantoin Suspension

    PubMed Central

    Moghimipour, Eskandar; Salimi, Anayatollah; Rezaee, Saeed; Balack, Maryam; Handali, Somayeh

    2014-01-01

    Background: Nitrofurantoin is a nitrofuran antibiotic that has been used for treatment of urinary tract against positive and negative bacteria. Objectives: The aim of this study was to evaluate the effect of structural vehicles and flocculating agents on physical stability and rheological behavior of nitrofurantoin suspension. Materials and Methods: To formulate the suspensions, the effect of glycerin and polysorbate 80 as wetting agents was evaluated and their particle sizes were determined using the sieve method. Then to achieve controlled flocculation, sodium citrate and aluminum chloride were added. After choosing the suitable wetting and flocculating agents, structural vehicles such as sodium carboxyl methyl cellulose and Veegum were evaluated individually and in combination. In addition, the effect of sorbitol on density of continuous phase and some physical stability parameters such as sedimentation volume, degree of flocculation and ease of redispersion of the suspensions were evaluated. After incorporation of structural vehicles, the rheological properties of formulations were also determined to find their flow behavior. Results: According to the results, glycerin (0.2%) and sodium citrate (0.3%) had the best effect on the suspension stability as wetting and flocculating agents, respectively. Rheological properties of formulations showed pseudoplastic behavior with some degree of thixotropy. Conclusions: In conclusion, the suspension containing Veegum 1%, sodium carboxy methyl cellulose 1%, glycerine 0.2%, sodium citrate 0.3% and sorbitol 20 % was chosen as the most physically stable formulation. PMID:24872937

  14. Reliable fuzzy H∞ control for active suspension of in-wheel motor driven electric vehicles with dynamic damping

    NASA Astrophysics Data System (ADS)

    Shao, Xinxin; Naghdy, Fazel; Du, Haiping

    2017-03-01

    A fault-tolerant fuzzy H∞ control design approach for active suspension of in-wheel motor driven electric vehicles in the presence of sprung mass variation, actuator faults and control input constraints is proposed. The controller is designed based on the quarter-car active suspension model with a dynamic-damping-in-wheel-motor-driven-system, in which the suspended motor is operated as a dynamic absorber. The Takagi-Sugeno (T-S) fuzzy model is used to model this suspension with possible sprung mass variation. The parallel-distributed compensation (PDC) scheme is deployed to derive a fault-tolerant fuzzy controller for the T-S fuzzy suspension model. In order to reduce the motor wear caused by the dynamic force transmitted to the in-wheel motor, the dynamic force is taken as an additional controlled output besides the traditional optimization objectives such as sprung mass acceleration, suspension deflection and actuator saturation. The H∞ performance of the proposed controller is derived as linear matrix inequalities (LMIs) comprising three equality constraints which are solved efficiently by means of MATLAB LMI Toolbox. The proposed controller is applied to an electric vehicle suspension and its effectiveness is demonstrated through computer simulation.

  15. Phase transition in a mixture of adaptive cruise control vehicles and manual vehicles

    NASA Astrophysics Data System (ADS)

    Jiang, R.; Hu, M.-B.; Jia, B.; Wang, R.; Wu, Q.-S.

    2007-07-01

    In this paper, we have investigated the effects of adaptive cruise control (ACC) vehicles in a mixture with manually-controlled (manual) vehicles. The manual vehicles are simulated by using the modified comfortable driving model, which can describe synchronized traffic flow. The phase transition probabilities from free flow to synchronized flow and from synchronized flow to jams are studied. The impact of ACC vehicles on the flow rates in free flow and synchronized flow and on the propagation velocity of the downstream front of jams are investigated. The dependence of microscopic properties of traffic flow, including the spatiotemporal patterns and the velocity distribution, is explored. Our results are expected to be useful for developing ACC systems.

  16. Adaptable System for Vehicle Health and Usage Monitoring

    NASA Technical Reports Server (NTRS)

    Woodart, Stanley E.; Woodman, Keith L.; Coffey, Neil C.; Taylor, Bryant D.

    2005-01-01

    Aircraft and other vehicles are often kept in service beyond their original design lives. As they age, they become susceptible to system malfunctions and fatigue. Unlike future aircraft that will include health-monitoring capabilities as integral parts in their designs, older aircraft have not been so equipped. The Adaptable Vehicle Health and Usage Monitoring System is designed to be retrofitted into a preexisting fleet of military and commercial aircraft, ships, or ground vehicles to provide them with state-of-the-art health- and usage-monitoring capabilities. The monitoring system is self-contained, and the integration of it into existing systems entails limited intrusion. In essence, it has bolt-on/ bolt-off simplicity that makes it easy to install on any preexisting vehicle or structure. Because the system is completely independent of the vehicle, it can be certified for airworthiness as an independent system. The purpose served by the health-monitoring system is to reduce vehicle operating costs and to increase safety and reliability. The monitoring system is a means to identify damage to, or deterioration of, vehicle subsystems, before such damage or deterioration becomes costly and/or disastrous. Frequent monitoring of a vehicle enables identification of the embryonic stages of damage or deterioration. The knowledge thus gained can be used to correct anomalies while they are still somewhat minor. Maintenance can be performed as needed, instead of having the need for maintenance identified during cyclic inspections that take vehicles off duty even when there are no maintenance problems. Measurements and analyses acquired by the health-monitoring system also can be used to analyze mishaps. Overall, vehicles can be made more reliable and kept on duty for longer times. Figure 1 schematically depicts the system as applied to a fleet of n vehicles. The system has three operational levels. All communication between system components is by use of wireless

  17. Autonomous underwater vehicle adaptive path planning for target classification

    NASA Astrophysics Data System (ADS)

    Edwards, Joseph R.; Schmidt, Henrik

    2002-11-01

    Autonomous underwater vehicles (AUVs) are being rapidly developed to carry sensors into the sea in ways that have previously not been possible. The full use of the vehicles, however, is still not near realization due to lack of the true vehicle autonomy that is promised in the label (AUV). AUVs today primarily attempt to follow as closely as possible a preplanned trajectory. The key to increasing the autonomy of the AUV is to provide the vehicle with a means to make decisions based on its sensor receptions. The current work examines the use of active sonar returns from mine-like objects (MLOs) as a basis for sensor-based adaptive path planning, where the path planning objective is to discriminate between real mines and rocks. Once a target is detected in the mine hunting phase, the mine classification phase is initialized with a derivative cost function to emphasize signal differences and enhance classification capability. The AUV moves adaptively to minimize the cost function. The algorithm is verified using at-sea data derived from the joint MIT/SACLANTCEN GOATS experiments and advanced acoustic simulation using SEALAB. The mission oriented operating system (MOOS) real-time simulator is then used to test the onboard implementation of the algorithm.

  18. Optimisation of active suspension control inputs for improved vehicle ride performance

    NASA Astrophysics Data System (ADS)

    Čorić, Mirko; Deur, Joško; Xu, Li; Tseng, H. Eric; Hrovat, Davor

    2016-07-01

    A collocation-type control variable optimisation method is used in the paper to analyse to which extent the fully active suspension (FAS) can improve the vehicle ride comfort while preserving the wheel holding ability. The method is first applied for a cosine-shaped bump road disturbance of different heights, and for both quarter-car and full 10 degree-of-freedom vehicle models. A nonlinear anti-wheel hop constraint is considered, and the influence of bump preview time period is analysed. The analysis is then extended to the case of square- or cosine-shaped pothole with different lengths, and the quarter-car model. In this case, the cost function is extended with FAS energy consumption and wheel damage resilience costs. The FAS action is found to be such to provide a wheel hop over the pothole, in order to avoid or minimise the damage at the pothole trailing edge. In the case of long pothole, when the FAS cannot provide the wheel hop, the wheel is travelling over the pothole bottom and then hops over the pothole trailing edge. The numerical optimisation results are accompanied by a simplified algebraic analysis.

  19. Adaptation of fibers in fast-twitch muscles of rats to spaceflight and hindlimb suspension

    NASA Technical Reports Server (NTRS)

    Jiang, Bian; Ohira, Yoshi; Roy, Roland R.; Nguyen, Quyet; Il'ina-Kakueva, E. I.; Oganov, V.; Edgerton, V. R.

    1992-01-01

    The adaptation of single fibers in medial gastrocnemius (MG), a fast-twitch extensor, and in tibialis anterior (TA), a fast-twitch flexor, was studied after 14 days of spaceflight onboard Cosmos 2044 or hindlimb suspension. Quantitative myosin ATPase activities of single fibers were measured in flight and suspended rats. Each of the enzyme and size measurements were directly correlated within each fiber with respect to its qualitative myosin ATPase staining properties and its expression of fast, slow, or both myosin heavy chains (MHC). The percentage of slow- and fast-twitch fibers of the MG and TA were found to be unchanged. Mean fiber size of all fibers was unaffected after flight or suspension. The ATPase activity in the MG was higher in flight than in control or suspended rats. In comparison to Cosmos 1887 spaceflight, the adaptations in the muscle fibers of the MG were more moderate.

  20. Adaptable and Adaptive Automation for Supervisory Control of Multiple Autonomous Vehicles

    DTIC Science & Technology

    2012-10-01

    Adaptable and Adaptive Automation for Supervisory Control of Multiple Autonomous Vehicles Brian Kidwell , 1 Gloria L. Calhoun, 2 Heath A. Ruff...correlated with selection of the high LOA ( r = .789, p < .01), as well as the disuse of the medium LOA ( r = -.823, p < .01). There was not a...AFRL. Brian Kidwell and Raja Parasuraman were supported by Air Force Office of Scientific Research grant FA9550-10-1-0385 and the Center of

  1. 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.

  2. 32 CFR 634.9 - Suspension or revocation of driving or privately owned vehicle registration privileges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Suspension or revocation of driving or privately... TRAFFIC SUPERVISION Driving Privileges § 634.9 Suspension or revocation of driving or privately owned... reason, administratively suspend or revoke driving privileges on the installation. The suspension...

  3. 32 CFR 634.9 - Suspension or revocation of driving or privately owned vehicle registration privileges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Suspension or revocation of driving or privately... TRAFFIC SUPERVISION Driving Privileges § 634.9 Suspension or revocation of driving or privately owned... reason, administratively suspend or revoke driving privileges on the installation. The suspension...

  4. 32 CFR 634.9 - Suspension or revocation of driving or privately owned vehicle registration privileges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Suspension or revocation of driving or privately... TRAFFIC SUPERVISION Driving Privileges § 634.9 Suspension or revocation of driving or privately owned... reason, administratively suspend or revoke driving privileges on the installation. The suspension...

  5. 32 CFR 634.9 - Suspension or revocation of driving or privately owned vehicle registration privileges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Suspension or revocation of driving or privately... TRAFFIC SUPERVISION Driving Privileges § 634.9 Suspension or revocation of driving or privately owned... reason, administratively suspend or revoke driving privileges on the installation. The suspension...

  6. Simulation analysis of the EUSAMA Plus suspension testing method including the impact of the vehicle untested side

    NASA Astrophysics Data System (ADS)

    Dobaj, K.

    2016-09-01

    The work deals with the simulation analysis of the half car vehicle model parameters on the suspension testing results. The Matlab simulation software was used. The considered model parameters are involved with the shock absorber damping coefficient, the tire radial stiffness, the car width and the rocker arm length. The consistent vibrations of both test plates were considered. Both wheels of the car were subjected to identical vibration, with frequency changed similar to the EUSAMA Plus principle. The shock absorber damping coefficient (for several values of the car width and rocker arm length) was changed on one and both sides of the vehicle. The obtained results are essential for the new suspension testing algorithm (basing on the EUSAMA Plus principle), which will be the aim of the further author's work.

  7. Design and Performance Evaluation of a Rotary Magnetorheological Damper for Unmanned Vehicle Suspension Systems

    PubMed Central

    Lee, Jae-Hoon; Han, Changwan; Ahn, Dongsu; Lee, Jin Kyoo; Park, Sang-Hu; Park, Seonghun

    2013-01-01

    We designed and validated a rotary magnetorheological (MR) damper with a specified damping torque capacity, an unsaturated magnetic flux density (MFD), and a high magnetic field intensity (MFI) for unmanned vehicle suspension systems. In this study, for the rotary type MR damper to have these satisfactory performances, the roles of the sealing location and the cover case curvature of the MR damper were investigated by using the detailed 3D finite element model to reflect asymmetrical shapes and sealing components. The current study also optimized the damper cover case curvature based on the MFD, the MFI, and the weight of the MR damper components. The damping torques, which were computed using the characteristic equation of the MR fluid and the MFI of the MR damper, were 239.2, 436.95, and 576.78 N·m at currents of 0.5, 1, and 1.5 A, respectively, at a disk rotating speed of 10 RPM. These predicted damping torques satisfied the specified damping torque of 475 N·m at 1.5 A and showed errors of less than 5% when compared to experimental measurements from the MR damper manufactured by the proposed design. The current study could play an important role in improving the performance of rotary type MR dampers. PMID:23533366

  8. Design and performance evaluation of a rotary magnetorheological damper for unmanned vehicle suspension systems.

    PubMed

    Lee, Jae-Hoon; Han, Changwan; Ahn, Dongsu; Lee, Jin Kyoo; Park, Sang-Hu; Park, Seonghun

    2013-01-01

    We designed and validated a rotary magnetorheological (MR) damper with a specified damping torque capacity, an unsaturated magnetic flux density (MFD), and a high magnetic field intensity (MFI) for unmanned vehicle suspension systems. In this study, for the rotary type MR damper to have these satisfactory performances, the roles of the sealing location and the cover case curvature of the MR damper were investigated by using the detailed 3D finite element model to reflect asymmetrical shapes and sealing components. The current study also optimized the damper cover case curvature based on the MFD, the MFI, and the weight of the MR damper components. The damping torques, which were computed using the characteristic equation of the MR fluid and the MFI of the MR damper, were 239.2, 436.95, and 576.78 N·m at currents of 0.5, 1, and 1.5 A, respectively, at a disk rotating speed of 10 RPM. These predicted damping torques satisfied the specified damping torque of 475 N·m at 1.5 A and showed errors of less than 5% when compared to experimental measurements from the MR damper manufactured by the proposed design. The current study could play an important role in improving the performance of rotary type MR dampers.

  9. Multi-objective design of vehicle suspension systems via a local diffusion genetic algorithm for disjoint Pareto frontiers

    NASA Astrophysics Data System (ADS)

    Aly, Mohamed F.; Nassef, Ashraf O.; Hamza, Karim

    2015-05-01

    This article presents a multi-objective design optimization study of a vehicle suspension system with passive variable stiffness and active damping. Design of suspension systems is particularly challenging when the effective mass of the vehicle is subject to considerable variation during service. Perfectly maintaining the suspension performance under the variable load typically requires a controlled actuator to emulate variable stiffness. This is typically done through a hydraulic or pneumatic system, which can be too costly for small/medium pick-up trucks. The system in this article employs two springs with an offset to the second spring so that it engages during large deformation only, thereby providing passive variable stiffness without expensive hydraulics. The system damping is assumed to be controlled via variable viscosity magnetizable fluid, which can be implemented in a compact, low-power set-up. Performance indices from the literature are evaluated at minimum and maximum weight, and regarded as objectives in a multi-objective problem. As the individual objectives are prone to having local optima, the multi-objective problem is prone to having a disjointed Pareto-space. To deal with this issue, a modification is proposed to a multi-objective genetic algorithm. The algorithm performance is investigated via analytical test functions as well as the design case of the suspension system.

  10. Adaptive controllability of omnidirectional vehicle over unpredictable terrain

    NASA Astrophysics Data System (ADS)

    Cheok, Ka C.; Radovnikovich, Micho; Hudas, Gregory R.; Overholt, James L.; Fleck, Paul

    2009-05-01

    In this paper, the controllability of a Mecanum omnidirectional vehicle (ODV) is investigated. An adaptive drive controller is developed that guides the ODV over irregular and unpredictable driving surfaces. Using sensor fusion with appropriate filtering, the ODV gets an accurate perception of the conditions it encounters and then adapts to them to robustly control its motion. Current applications of Mecanum ODVs are designed for use on smooth, regular driving surfaces, and don't actively detect the characteristics of disturbances in the terrain. The intention of this work is to take advantage of the mobility of ODVs in environments where they weren't originally intended to be used. The methods proposed in this paper were implemented in hardware on an ODV. Experimental results did not perform as designed due to incorrect assumptions and over-simplification of the system model. Future work will concentrate on developing more robust control schemes to account for the unknown nonlinear dynamics inherent in the system.

  11. Monitoring changes in proteome during stepwise adaptation of a MDCK cell line from adherence to growth in suspension.

    PubMed

    Kluge, Sabine; Benndorf, Dirk; Genzel, Yvonne; Scharfenberg, Klaus; Rapp, Erdmann; Reichl, Udo

    2015-08-20

    Adaptation of continuous cell lines to growth in suspension in a chemically defined medium has significant advantages for design and optimization in manufacturing of biologicals. In this work, changes in the protein expression level during a step-wise adaptation of an adherent Madin Darby canine kidney (MDCK) cell line to suspension growth were analyzed. Therefore, three cell line adaptations were performed independently. Two adaptations were monitored closely to characterize short term changes in protein expression levels after serum deprivation. In addition, initial stages of suspension growth were analyzed for both adaptations. The third adaptation involved MDCK suspension cells (MDCKSUS2) grown over an extended time period to achieve robust growth characteristics. Here, cells of the final stage of adaptation were compared with their parental cell line (MDCKADH). A combination of two dimensional differential gel electrophoresis for relative protein quantification and tandem mass spectrometry for protein identification enabled insights into cellular physiology. The two closely monitored cell line adaptations followed different routes regarding specific changes in protein expression but resulted in similar proteome profiles at the initial stages of suspension growth analyzed. Compared to the MDCKADH cells more than 90% of all changes in the protein expression level were identified after serum deprivation and were related to cytoskeletal structure, genetic information processing and cellular metabolism. Myosin proteins, involved in cellular detachment by actin-myosin contractile mechanisms were also differentially expressed. Interestingly, for both of the two adaptations, proteins linked for tumorigenicity, like lactoylglutathione lyase and sulfotransferase 1A1 were differentially expressed. In contrast, none of these proteins were differentially expressed for the MDCKSUS2 cell line. Overall, proteomic monitoring allowed identification of key proteins involved in

  12. Launch vehicle payload adapter design with vibration isolation features

    NASA Astrophysics Data System (ADS)

    Thomas, Gareth R.; Fadick, Cynthia M.; Fram, Bryan J.

    2005-05-01

    Payloads, such as satellites or spacecraft, which are mounted on launch vehicles, are subject to severe vibrations during flight. These vibrations are induced by multiple sources that occur between liftoff and the instant of final separation from the launch vehicle. A direct result of the severe vibrations is that fatigue damage and failure can be incurred by sensitive payload components. For this reason a payload adapter has been designed with special emphasis on its vibration isolation characteristics. The design consists of an annular plate that has top and bottom face sheets separated by radial ribs and close-out rings. These components are manufactured from graphite epoxy composites to ensure a high stiffness to weight ratio. The design is tuned to keep the frequency of the axial mode of vibration of the payload on the flexibility of the adapter to a low value. This is the main strategy adopted for isolating the payload from damaging vibrations in the intermediate to higher frequency range (45Hz-200Hz). A design challenge for this type of adapter is to keep the pitch frequency of the payload above a critical value in order to avoid dynamic interactions with the launch vehicle control system. This high frequency requirement conflicts with the low axial mode frequency requirement and this problem is overcome by innovative tuning of the directional stiffnesses of the composite parts. A second design strategy that is utilized to achieve good isolation characteristics is the use of constrained layer damping. This feature is particularly effective at keeping the responses to a minimum for one of the most important dynamic loading mechanisms. This mechanism consists of the almost-tonal vibratory load associated with the resonant burn condition present in any stage powered by a solid rocket motor. The frequency of such a load typically falls in the 45-75Hz range and this phenomenon drives the low frequency design of the adapter. Detailed finite element analysis is

  13. Equivalent Air Spring Suspension Model for Quarter-Passive Model of Passenger Vehicles.

    PubMed

    Abid, Haider J; Chen, Jie; Nassar, Ameen A

    2015-01-01

    This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system.

  14. Workload Model Based Dynamic Adaptation of Social Internet of Vehicles.

    PubMed

    Alam, Kazi Masudul; Saini, Mukesh; El Saddik, Abdulmotaleb

    2015-09-15

    Social Internet of Things (SIoT) has gained much interest among different research groups in recent times. As a key member of a smart city, the vehicular domain of SIoT (SIoV) is also undergoing steep development. In the SIoV, vehicles work as sensor-hub to capture surrounding information using the in-vehicle and Smartphone sensors and later publish them for the consumers. A cloud centric cyber-physical system better describes the SIoV model where physical sensing-actuation process affects the cloud based service sharing or computation in a feedback loop or vice versa. The cyber based social relationship abstraction enables distributed, easily navigable and scalable peer-to-peer communication among the SIoV subsystems. These cyber-physical interactions involve a huge amount of data and it is difficult to form a real instance of the system to test the feasibility of SIoV applications. In this paper, we propose an analytical model to measure the workloads of various subsystems involved in the SIoV process. We present the basic model which is further extended to incorporate complex scenarios. We provide extensive simulation results for different parameter settings of the SIoV system. The findings of the analyses are further used to design example adaptation strategies for the SIoV subsystems which would foster deployment of intelligent transport systems.

  15. Workload Model Based Dynamic Adaptation of Social Internet of Vehicles

    PubMed Central

    Alam, Kazi Masudul; Saini, Mukesh; El Saddik, Abdulmotaleb

    2015-01-01

    Social Internet of Things (SIoT) has gained much interest among different research groups in recent times. As a key member of a smart city, the vehicular domain of SIoT (SIoV) is also undergoing steep development. In the SIoV, vehicles work as sensor-hub to capture surrounding information using the in-vehicle and Smartphone sensors and later publish them for the consumers. A cloud centric cyber-physical system better describes the SIoV model where physical sensing-actuation process affects the cloud based service sharing or computation in a feedback loop or vice versa. The cyber based social relationship abstraction enables distributed, easily navigable and scalable peer-to-peer communication among the SIoV subsystems. These cyber-physical interactions involve a huge amount of data and it is difficult to form a real instance of the system to test the feasibility of SIoV applications. In this paper, we propose an analytical model to measure the workloads of various subsystems involved in the SIoV process. We present the basic model which is further extended to incorporate complex scenarios. We provide extensive simulation results for different parameter settings of the SIoV system. The findings of the analyses are further used to design example adaptation strategies for the SIoV subsystems which would foster deployment of intelligent transport systems. PMID:26389905

  16. Method for reducing the drag of blunt-based vehicles by adaptively increasing forebody roughness

    NASA Technical Reports Server (NTRS)

    Whitmore, Stephen A. (Inventor); Saltzman, Edwin J. (Inventor); Moes, Timothy R. (Inventor); Iliff, Kenneth W. (Inventor)

    2005-01-01

    A method for reducing drag upon a blunt-based vehicle by adaptively increasing forebody roughness to increase drag at the roughened area of the forebody, which results in a decrease in drag at the base of this vehicle, and in total vehicle drag.

  17. Robust adaptive backstepping control for reentry reusable launch vehicles

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Wu, Zhong; Du, Yijiang

    2016-09-01

    During the reentry process of reusable launch vehicles (RLVs), the large range of flight envelope will not only result in high nonlinearities, strong coupling and fast time-varying characteristics of the attitude dynamics, but also result in great uncertainties in the atmospheric density, aerodynamic coefficients and environmental disturbances, etc. In order to attenuate the effects of these problems on the control performance of the reentry process, a robust adaptive backstepping control (RABC) strategy is proposed for RLV in this paper. This strategy consists of two-loop controllers designed via backstepping method. Both the outer and the inner loop adopt a robust adaptive controller, which can deal with the disturbances and uncertainties by the variable-structure term with the estimation of their bounds. The outer loop can track the desired attitude by the design of virtual control-the desired angular velocity, while the inner one can track the desired angular velocity by the design of control torque. Theoretical analysis indicates that the closed-loop system under the proposed control strategy is globally asymptotically stable. Even if the boundaries of the disturbances and uncertainties are unknown, the attitude can track the desired value accurately. Simulation results of a certain RLV demonstrate the effectiveness of the control strategy.

  18. Membrane and adaptively-shaped wings for micro air vehicles

    NASA Astrophysics Data System (ADS)

    Lian, Yongsheng

    Micro air vehicles (MAVs), with wing span of 15 cm or less and flight speed around 10 m/s, have many applications in both civilian and military areas. The Reynolds number based on the given parameters is around 10 4, which often yields insufficient lift-to-drag ratio. Furthermore, one expects the unsteady effect to be noticeable for such flight vehicles. The flexible wing has been demonstrated to exhibit favorable characteristics such as passive adaptation to the flight; environment and delayed stall. The present study focuses on developing computational and modeling capabilities to better understand the MAV aerodynamics. Both flexible wings, utilizing membrane materials, and adaptively-shaped wings, utilizing piezo-actuated flaps, have been studied. In the adaptively-shaped wing study, we use piezo-actuated flaps to actively control the flow. We assess the impacts of the flap geometry, flapping amplitude, and turbulence; modeling on the flow structure with a parallel experimental effort. The membrane wing uses a passive control mechanism to delay the stall angle and to provide a smoother flight platform. Our study focuses on the mutual interactions between the membrane wing and its surrounding viscous flow. We compare the lift-to-drag ratio and the flow structure between the flexible wing and the corresponding rigid wing. We also investigate the aerodynamic characteristics associated with the low Reynolds number and low aspect ratio wing. To assist our study, we propose an automatic and efficient moving grid technique to facilitate the fluid and structure interaction computations; we also present a dynamic membrane model to study the intrinsic large deformation of the flexible membrane wing. Solutions obtained from the three-dimensional Navier-Stokes equations are presented to highlight, the salient features of the wing aerodynamics. Besides the aerodynamic study, we also perform shape optimization to improve the membrane wing performance. Since direct

  19. Adaptive Neuro-Fuzzy Determination of the Effect of Experimental Parameters on Vehicle Agent Speed Relative to Vehicle Intruder

    PubMed Central

    Shamshirband, Shahaboddin; Banjanovic-Mehmedovic, Lejla; Bosankic, Ivan; Kasapovic, Suad; Abdul Wahab, Ainuddin Wahid Bin

    2016-01-01

    Intelligent Transportation Systems rely on understanding, predicting and affecting the interactions between vehicles. The goal of this paper is to choose a small subset from the larger set so that the resulting regression model is simple, yet have good predictive ability for Vehicle agent speed relative to Vehicle intruder. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data resulting from these measurements. The ANFIS process for variable selection was implemented in order to detect the predominant variables affecting the prediction of agent speed relative to intruder. This process includes several ways to discover a subset of the total set of recorded parameters, showing good predictive capability. The ANFIS network was used to perform a variable search. Then, it was used to determine how 9 parameters (Intruder Front sensors active (boolean), Intruder Rear sensors active (boolean), Agent Front sensors active (boolean), Agent Rear sensors active (boolean), RSSI signal intensity/strength (integer), Elapsed time (in seconds), Distance between Agent and Intruder (m), Angle of Agent relative to Intruder (angle between vehicles °), Altitude difference between Agent and Intruder (m)) influence prediction of agent speed relative to intruder. The results indicated that distance between Vehicle agent and Vehicle intruder (m) and angle of Vehicle agent relative to Vehicle Intruder (angle between vehicles °) is the most influential parameters to Vehicle agent speed relative to Vehicle intruder. PMID:27219539

  20. Adaptive Neuro-Fuzzy Determination of the Effect of Experimental Parameters on Vehicle Agent Speed Relative to Vehicle Intruder.

    PubMed

    Shamshirband, Shahaboddin; Banjanovic-Mehmedovic, Lejla; Bosankic, Ivan; Kasapovic, Suad; Abdul Wahab, Ainuddin Wahid Bin

    2016-01-01

    Intelligent Transportation Systems rely on understanding, predicting and affecting the interactions between vehicles. The goal of this paper is to choose a small subset from the larger set so that the resulting regression model is simple, yet have good predictive ability for Vehicle agent speed relative to Vehicle intruder. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data resulting from these measurements. The ANFIS process for variable selection was implemented in order to detect the predominant variables affecting the prediction of agent speed relative to intruder. This process includes several ways to discover a subset of the total set of recorded parameters, showing good predictive capability. The ANFIS network was used to perform a variable search. Then, it was used to determine how 9 parameters (Intruder Front sensors active (boolean), Intruder Rear sensors active (boolean), Agent Front sensors active (boolean), Agent Rear sensors active (boolean), RSSI signal intensity/strength (integer), Elapsed time (in seconds), Distance between Agent and Intruder (m), Angle of Agent relative to Intruder (angle between vehicles °), Altitude difference between Agent and Intruder (m)) influence prediction of agent speed relative to intruder. The results indicated that distance between Vehicle agent and Vehicle intruder (m) and angle of Vehicle agent relative to Vehicle Intruder (angle between vehicles °) is the most influential parameters to Vehicle agent speed relative to Vehicle intruder.

  1. Model predictive control with constraints for a nonlinear adaptive cruise control vehicle model in transition manoeuvres

    NASA Astrophysics Data System (ADS)

    Ali, Zeeshan; Popov, Atanas A.; Charles, Guy

    2013-06-01

    A vehicle following control law, based on the model predictive control method, to perform transition manoeuvres (TMs) for a nonlinear adaptive cruise control (ACC) vehicle is presented in this paper. The TM controller ultimately establishes a steady-state following distance behind a preceding vehicle to avoid collision, keeping account of acceleration limits, safe distance, and state constraints. The vehicle dynamics model is for continuous-time domain and captures the real dynamics of the sub-vehicle models for steady-state and transient operations. The ACC vehicle can execute the TM successfully and achieves a steady-state in the presence of complex dynamics within the constraint boundaries.

  2. Electrophysiological, histochemical, and hormonal adaptation of rat muscle after prolonged hindlimb suspension

    NASA Astrophysics Data System (ADS)

    Kourtidou-Papadeli, Chrysoula; Kyparos, Antonios; Albani, Maria; Frossinis, Athanasios; Papadelis, Christos L.; Bamidis, Panagiotis; Vivas, Ana; Guiba-Tziampiri, Olympia

    2004-05-01

    The perspective of long-duration flights for future exploration, imply more research in the field of human adaptation. Previous studies in rat muscles hindlimb suspension (HLS), indicated muscle atrophy and a change of fibre composition from slow-to-fast twitch types. However, the contractile responses to long-term unloading is still unclear. Fifteen adult Wistar rats were studied in 45 and 70 days of muscle unweighting and soleus (SOL) muscle as well as extensor digitorum longus (EDL) were prepared for electrophysiological recordings (single, twitch, tetanic contraction and fatigue) and histochemical stainings. The loss of muscle mass observed was greater in the soleus muscle. The analysis of electrophysiological properties of both EDL and SOL showed significant main effects of group, of number of unweighting days and fatigue properties. Single contraction for soleus muscle remained unchanged but there was statistically significant difference for tetanic contraction and fatigue. Fatigue index showed a decrease for the control rats, but increase for the HLS rats. According to the histochemical findings there was a shift from oxidative to glycolytic metabolism during HLS. The data suggested that muscles atrophied, but they presented an adaptation pattern, while their endurance in fatigue was decreased.

  3. A seat suspension with a rotary magnetorheological damper for heavy duty vehicles

    NASA Astrophysics Data System (ADS)

    Sun, S. S.; Ning, D. H.; Yang, J.; Du, H.; Zhang, S. W.; Li, W. H.

    2016-10-01

    This paper presents the development of an innovative seat suspension working with a rotary magnetorheological (MR) fluid damper. Compared with a conventional linear MR damper, the well-designed rotary MR damper possesses several advantages such as usage reduction of magnetorheological fluid, low sealing requirements and lower costs. This research starts with the introduction of the seat suspension structure and the damper design, followed by the property test of the seat suspension using an MTS machine. The field-dependent property, amplitude-dependent performance, and the frequency-dependent performance of the new seat suspension are measured and evaluated. This research puts emphasis on the evaluation of the vibration reduction capability of the rotary MR damper by using both simulation and experimental methods. Fuzzy logic is chosen to control the rotary MR damper in real time and two different input signals are considered as vibration excitations. The experimental results show that the rotary MR damper under fuzzy logic control is effective in reducing the vibrations.

  4. Experimental Validation of a Multibody Dynamics Model of the Suspension System of a Tracked Vehicle

    DTIC Science & Technology

    2011-08-09

    of the suspension system rotational deflections are experimentally measured for the various input motion excitations. The experimental measurements...including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson...large rotations and large deflections (of the flexible track). A review of flexible multibody dynamics modeling techniques including deformation

  5. 32 CFR 634.9 - Suspension or revocation of driving or privately owned vehicle registration privileges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... installation parking regulations. The commander will determine standards for suspension based on frequency of..., family members, retired members of the military services, DOD civilian personnel, and others with installation or overseas command driving privileges, regardless of the geographic location of the...

  6. Evaluation of the Stability of Mercaptopurine Suspension Compounded in a Commercial Vehicle and the Determination of an Appropriate Beyond-use Date.

    PubMed

    Peacock, Gina F; Sauvageot, Jurgita; Hill, Ashley; Killian, Alyssa

    2016-01-01

    Mercaptopurine is commonly used to treat acute lymphoblastic leukemia and has historically been commercially available only in tablet form. Since tablets may be difficult for children and elderly patients to swallow, many pharmacists have compounded mercaptopurine suspensions. The U.S. Food and Drug Administration recently approved a commercial suspension, but it is not widely available at this time. Therefore, pharmacists may still need to compound mercaptopurine suspension for use in areas where it is not available or if the commercial suspension is in short supply. Stability studies must be conducted in order to assign appropriate beyond-use dates for compounded preparations. The objective of this study was to evaluate the stability of extemporaneously compounded suspensions using commercially available mercaptopurine tablets, as well as active pharmaceutical ingredient in a vehicle of Ora-Sweet and Ora-Plus (1:1) stored in plastic and glass containers at room temperature. Each mercaptopurine preparation was analyzed using a validated stability-indicating high-performance liquid chromatography method at the following time points: 0, 7, 14, 21, 30, 60, and 90 days. Suspensions were also observed for changes in appearance or odor, and pH was tested at each time point. The suspension compounded from Roxane generic tablets was extremely viscous and was therefore eliminated from the study. All other suspensions showed no observed physical changes and maintained greater than 93% of initial concentration of mercaptopurine for the entire study period.

  7. Stability of adaptive cruise control systems taking account of vehicle response time and delay

    NASA Astrophysics Data System (ADS)

    Davis, L. C.

    2012-08-01

    The region of string stability of a platoon of adaptive cruise control vehicles, taking into account the delay and response of the vehicle powertrain, is found. An upper bound on the explicit delay time as a function the first-order powertrain response time constant is determined. The system is characterized by a headway time constant, a sensitivity parameter, relative (to the vehicle immediately in front) velocity control, and delayed-velocity feedback or acceleration feedback.

  8. Assessment of Adaptive Guidance for Responsive Launch Vehicles and Spacecraft

    DTIC Science & Technology

    2009-04-29

    Coordinate Systems 6 3.1 Earth Centered Inertial Coordinate System XIYIZI . . . . . . . . . . . . . . 6 3.2 Launch Guidance (Plumbline) System XPYPZP...Figures 1 Earth centered inertial and launch plumbline coordinate systems . . . . . . . 7 2 Geodetic and geocentric latitude...8 3 Vehicle body coordinate system showing Euler angles . . . . . . . . . . . . . 9 4 Launch vehicle body frame with

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

    DTIC Science & Technology

    2013-04-01

    torque convertor characteristics, and transmission gear ratios and efficiencies. A representative TruckSim tactical vehicle model (modified High...different type of nonlinear control algorithm, called single experiment–multiple pulses , was also considered and developed using Matlab/Simulink. This...vibration to the vehicle body. This effect indicates that the controllable dynamic force range, defined as the ratio of the field-on damping force

  10. Suspension Geometry Measuring

    NASA Astrophysics Data System (ADS)

    Kao, M. J.; Yu, C. C.; Chang, H.; Tsung, T. T.; Lin, H. M.

    2006-10-01

    This paper describes the instrumentation and analysis of the Vehicle suspension's electrical signals. It will measure the Vehicle suspensions' Vertical Displacement, Track Change, Camber Angle, Caster Angle Steer Angle and convert physical quantity into electrical signals in a various vehicle load change. With using electrical signals for computer control, the electrical controlled vehicle has brought great convenience, great safety and thoughtful kindness vehicle system in our daily life. It will measure the Vehicle suspensions' Vertical Displacement, Track Change, Camber Angle, Caster Angle Steer Angle and convert physical quantity into electrical signals in a various vehicle load change. The function of a suspension system in an automobile is to improve ride comfort and stability. Advances in electronic control technology, applied to the automobile, can improve those functions. The results show that the photocell can convert the electrical signals of suspension for peripheral communications link between the vehicle driving and the electronic control unit (ECU) employed for processing.

  11. Partial weight suspension: a novel murine model for investigating adaptation to reduced musculoskeletal loading.

    PubMed

    Wagner, Erika B; Granzella, Nicholas P; Saito, Hiroaki; Newman, Dava J; Young, Laurence R; Bouxsein, Mary L

    2010-08-01

    We developed a new model of hypodynamic loading to support mice in chronic conditions of partial weight bearing, enabling simulations of reduced gravity environments and related clinical conditions. The novel hardware allows for reduced loading between 10 and 80% of normal body weight on all four limbs and enables characteristic quadrupedal locomotion. Ten-week-old female BALB/cByJ mice were supported for 21 days under Mars-analog suspension (38% weight bearing) and compared with age-matched and jacketed (100% weight bearing) controls. After an initial adaptation, weight gain did not differ between groups, suggesting low levels of animal stress. Relative to age-matched controls, mice exposed to Mars-analog loading had significantly lower muscle mass (-23% gastrocnemius wet mass, P < 0.0001); trabecular and cortical bone morphology (i.e., trabecular bone volume: -24% at the distal femur, and cortical thickness: -11% at the femoral midshaft, both P < 0.001); and biomechanical properties of the femoral midshaft (i.e., -27% ultimate moment, P < 0.001). Bone formation indexes were decreased compared with age-matched full-weight-bearing mice, whereas resorption parameters were largely unchanged. Singly housed, full-weight-bearing controls with forelimb jackets were largely similar to age-matched, group-housed controls, although a few variables differed and warrant further investigation. Altogether, these data provide strong rationale for use of our new model of partial weight bearing to further explore the musculoskeletal response to reduced loading environments.

  12. Test techniques: A survey paper on cryogenic tunnels, adaptive wall test sections, and magnetic suspension and balance systems

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.; Dress, David A.; Wolf, Stephen W. D.; Britcher, Colin P.

    1989-01-01

    The ability to get good experimental data in wind tunnels is often compromised by things seemingly beyond our control. Inadequate Reynolds number, wall interference, and support interference are three of the major problems in wind tunnel testing. Techniques for solving these problems are available. Cryogenic wind tunnels solve the problem of low Reynolds number. Adaptive wall test sections can go a long way toward eliminating wall interference. A magnetic suspension and balance system (MSBS) completely eliminates support interference. Cryogenic tunnels, adaptive wall test sections, and MSBS are surveyed. A brief historical overview is given and the present state of development and application in each area is described.

  13. Digital adaptive controllers for VTOL vehicles. Volume 2: Software documentation

    NASA Technical Reports Server (NTRS)

    Hartmann, G. L.; Stein, G.; Pratt, S. G.

    1979-01-01

    The VTOL approach and landing test (VALT) adaptive software is documented. Two self-adaptive algorithms, one based on an implicit model reference design and the other on an explicit parameter estimation technique were evaluated. The organization of the software, user options, and a nominal set of input data are presented along with a flow chart and program listing of each algorithm.

  14. Autonomous & Adaptive Oceanographic Feature Tracking on Board Autonomous Underwater Vehicles

    DTIC Science & Technology

    2015-02-01

    Underwater Vehicles MIT/WHOI Joint Program in Oceanography/ Applied Ocean Science and Engineering Massachusetts Institute of Technology Woods Hole ...Massachusetts Institute of Technology Cambridge, Massachusetts 02139 and Woods Hole Oceanographic Institution Woods Hole , Massachusetts 02543...Undersea Warfare Center and the Woods Hole Oceanographic Institution Academic Programs Office. Reproduction in whole or in part is permitted for any

  15. Digital adaptive controllers for VTOL vehicles. Volume 1: Concept evaluation

    NASA Technical Reports Server (NTRS)

    Hartmann, G. L.; Stein, G.; Pratt, S. G.

    1979-01-01

    A digital self-adaptive flight control system was developed for flight test in the VTOL approach and landing technology (VALT) research aircraft (a modified CH-47 helicopter). The control laws accept commands from an automatic on-board guidance system. The primary objective of the control laws is to provide good command-following with a minimum cross-axis response. Three attitudes and vertical velocity are separately commanded. Adaptation of the control laws is based on information from rate and attitude gyros and a vertical velocity measurement. The final design resulted from a comparison of two different adaptive concepts--one based on explicit parameter estimates from a real-time maximum-likelihood estimation algorithm, the other based on an implicit model reference adaptive system. The two designs were compared on the basis of performance and complexity.

  16. Real Time Adaptive Control of an Autonomous Underwater Vehicle (AUV)

    DTIC Science & Technology

    1989-09-01

    design of a control system f or the AUV, since knowledge of an accurate dynamic model is in general the basis of a reliable control design. Also, tests...designer the possibility of using this simple nominal model, possibly linear while still preserving the global stability ol. he controlled system . 3...control system . The parameters a, c arid K0 in (2.4a) depend on the operating 9 conditions (speed, primarily) of the vehicle, and can be determined on the

  17. Suppressing Vertical Vibration in Railway Vehicles through Primary Suspension Damping Force Control

    NASA Astrophysics Data System (ADS)

    Sugahara, Yoshiki; Takigami, Tadao; Sampei, Mitsuji

    Suppression of the vertical bending vibration of carbodies has recently become essential in improving the riding comfort of railway vehicles. In many cases, the resonant frequency of the system (consisting of a bogie frame and axle springs) is close to that of the first mode bending vibration of the carbody, so suppressing the vibration of bogie frames near their resonant frequency effectively reduces carbody vibration. In this paper, we propose a method of suppressing such vibration by controlling the damping force of axle dampers installed between bogie frames and wheel sets. The design of the semi-active controller applied to determine the optimal damping force is based on the sky hook control theory. Numerical simulations using a vehicle model with 16 degrees of freedom as well as excitation tests using a carbody with variable axle dampers at a rolling stock test plant were carried out. The results show that this control method effectively reduces the power spectral density (PSD) of acceleration on the floor and that the riding comfort level (LT) can be improved by about 3 dB.

  18. Foundations for learning and adaptation in a multi-degree-of-freedom unmanned ground vehicle

    NASA Astrophysics Data System (ADS)

    Blackburn, Michael R.; Bailey, Richard

    2004-04-01

    The real-time coordination and control of a many motion degrees of freedom (dof) unmanned ground vehicle under dynamic conditions in a complex environment is nearly impossible for a human operator to accomplish. Needed are adaptive on-board mechanisms to quickly complete sensor-effector loops to maintain balance and leverage. This paper contains a description of our approach to the control problem for a small unmanned ground vehicle with six dof in the three spatial dimensions. Vehicle control is based upon seven fixed action patterns that exercise all of the motion dof of which the vehicle is capable, and five basic reactive behaviors that protect the vehicle during operation. The reactive behaviors demonstrate short-term adaptations. The learning processes for long-term adaptations of the vehicle control functions that we are implementing are composed of classical and operant conditionings of novel responses to information available from distance sensors (vision and audition) built upon the pre-defined fixed action patterns. The fixed action patterns are in turn modulated by the pre-defined low-level reactive behaviors that, as unconditioned responses, continuously serve to maintain the viability of the robot during the activations of the fixed action patterns, and of the higher-order (conditioned) behaviors. The sensors of the internal environment that govern the low-level reactive behaviors also serve as the criteria for operant conditioning, and satisfy the requirement for basic behavioral motivation.

  19. Passenger thermal perceptions, thermal comfort requirements, and adaptations in short- and long-haul vehicles.

    PubMed

    Lin, Tzu-Ping; Hwang, Ruey-Lung; Huang, Kuo-Tsang; Sun, Chen-Yi; Huang, Ying-Che

    2010-05-01

    While thermal comfort in mass transportation vehicles is relevant to service quality and energy consumption, benchmarks for such comfort that reflect the thermal adaptations of passengers are currently lacking. This study reports a field experiment involving simultaneous physical measurements and a questionnaire survey, collecting data from 2,129 respondents, that evaluated thermal comfort in short- and long-haul buses and trains. Experimental results indicate that high air temperature, strong solar radiation, and low air movement explain why passengers feel thermally uncomfortable. The overall insulation of clothing worn by passengers and thermal adaptive behaviour in vehicles differ from those in their living and working spaces. Passengers in short-haul vehicles habitually adjust the air outlets to increase thermal comfort, while passengers in long-haul vehicles prefer to draw the drapes to reduce discomfort from extended exposure to solar radiation. The neutral temperatures for short- and long-haul vehicles are 26.2 degrees C and 27.4 degrees C, while the comfort zones are 22.4-28.9 degrees C and 22.4-30.1 degrees C, respectively. The results of this study provide a valuable reference for practitioners involved in determining the adequate control and management of in-vehicle thermal environments, as well as facilitating design of buses and trains, ultimately contributing to efforts to achieve a balance between the thermal comfort satisfaction of passengers and energy conserving measures for air-conditioning in mass transportation vehicles.

  20. FUN3D Grid Refinement and Adaptation Studies for the Ares Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Bartels, Robert E.; Vasta, Veer; Carlson, Jan-Renee; Park, Mike; Mineck, Raymond E.

    2010-01-01

    This paper presents grid refinement and adaptation studies performed in conjunction with computational aeroelastic analyses of the Ares crew launch vehicle (CLV). The unstructured grids used in this analysis were created with GridTool and VGRID while the adaptation was performed using the Computational Fluid Dynamic (CFD) code FUN3D with a feature based adaptation software tool. GridTool was developed by ViGYAN, Inc. while the last three software suites were developed by NASA Langley Research Center. The feature based adaptation software used here operates by aligning control volumes with shock and Mach line structures and by refining/de-refining where necessary. It does not redistribute node points on the surface. This paper assesses the sensitivity of the complex flow field about a launch vehicle to grid refinement. It also assesses the potential of feature based grid adaptation to improve the accuracy of CFD analysis for a complex launch vehicle configuration. The feature based adaptation shows the potential to improve the resolution of shocks and shear layers. Further development of the capability to adapt the boundary layer and surface grids of a tetrahedral grid is required for significant improvements in modeling the flow field.

  1. 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

  2. Biomechanics and structural adaptations of the rat femur after hindlimb suspension and treadmill running.

    PubMed

    Shimano, M M; Volpon, J B

    2009-04-01

    We microscopically and mechanically evaluated the femurs of rats subjected to hindlimb unloading (tail suspension) followed by treadmill training. Female Wistar rats were randomly divided into five groups containing 12-14 rats: control I (118 days old), control II (139 days old), suspended (tail suspension for 28 days), suspended-released (released for 21 days after 28 days of suspension), and suspended-trained (trained for 21 days after 28 days of suspension). We measured bone resistance by bending-compression mechanical tests of the entire proximal half of the femur and three-point bending tests of diaphyseal cortical bone. We determined bone microstructure by tetracycline labeling of trabecular and cortical bone. We found that tail suspension weakened bone (ultimate load = 86.3 +/- 13.5 N, tenacity modulus = 0.027 +/- 0.011 MPa.m vs ultimate load = 101.5 +/- 10.5 N, tenacity modulus = 0.019 +/- 0.006 MPa.m in control I animals). The tenacity modulus for suspended and released animals was 0.023 +/- 0.010 MPa.m vs 0.046 +/- 0.018 MPa.m for trained animals and 0.035 +/- 0.010 MPa.m for control animals. These data indicate that normal activity and training resulted in recovered bone resistance, but suspended-released rats presented femoral head flattening and earlier closure of the growth plate. Microscopically, we found that suspension inhibited new bone subperiosteal and endosteal formation. The bone disuse atrophy secondary to hypoactivity in rats can be reversed by an early regime of exercising, which is more advantageous than ordinary cage activities alone.

  3. Neural Network Based Adaptive Flow Control for Maneuvering Vehicles

    DTIC Science & Technology

    2005-09-01

    effective nonlinear adaptive control of the aerodynamic flow about a dynamic body using a distributed array of synthetic jets for actuation. Design of a wind...possible coupling effects between actuation, the dynamics of flow field, and the rigid body dynamics of the model. The outcomes of simulation studies are...presented. The parameters were selected to have an adverse effect on the closed loop response, therefore representing a hypothetical worst-case

  4. Method for Reducing the Drag of Increasing Forebody Roughness Blunt-Based Vehicles by Adaptively Increasing Forebody Roughness

    NASA Technical Reports Server (NTRS)

    Whitmore, Stephen A. (Inventor); Saltzman, Edwin J. (Inventor); Moes, Timothy R. (Inventor); Iliff, Kenneth W. (Inventor)

    2005-01-01

    A method for reducing drag upon a blunt-based vehicle by adaptively increasing forebody roughness to increase drag at the roughened area of the forebody, which results in a decrease in drag at the base of this vehicle, and in total vehicle drag.

  5. Nonlinear Adaptive Control and Guidance for Unstart Recovery for a Generic Hypersonic Vehicle

    NASA Astrophysics Data System (ADS)

    Gunbatar, Yakup

    This work presents the development of an integrated flight controller for a generic model of a hypersonic air-breathing vehicle. The flight control architecture comprises a guidance and trajectory planning module and a nonlinear inner-loop adaptive controller. The emphasis of the controller design is on achieving stable tracking of suitable reference trajectories in the presence of a specific engine fault (inlet unstart), in which sudden and drastic changes in the vehicle aerodynamics and engine performance occur. First, the equations of motion of the vehicle for a rigid body model, taking the rotation of the Earth into account, is provided. Aerodynamic forces and moments and engine data are provided in lookup-table format. This comprehensive model is used for simulations and verification of the control strategies. Then, a simplified control-oriented model is developed for the purpose of control design and stability analysis. The design of the guidance and nonlinear adaptive control algorithms is first carried out on a longitudinal version of the vehicle dynamics. The design is verified in a simulation study aiming at testing the robustness of the inner-loop controller under significant model uncertainty and engine failures. At the same time, the guidance system provides reference trajectories to maximize the vehicle's endurance, which is cast as an optimal control problem. The design is then extended to tackle the significantly more challenging case of the 6-degree-of-freedom (6-DOF) vehicle dynamics. For the full 6-DOF case, the adaptive nonlinear flight controller is tested on more challenging maneuvers, where values of the flight path and bank angles exceed the nominal range defined for the vehicle. Simulation studies show stable operation of the closed-loop system in nominal operating conditions, unstart conditions, and during transition from sustained scramjet propulsion to engine failure mode.

  6. Launch Vehicle Manual Steering with Adaptive Augmenting Control In-flight Evaluations Using a Piloted Aircraft

    NASA Technical Reports Server (NTRS)

    Hanson, Curt

    2014-01-01

    An adaptive augmenting control algorithm for the Space Launch System has been developed at the Marshall Space Flight Center as part of the launch vehicles baseline flight control system. A prototype version of the SLS flight control software was hosted on a piloted aircraft at the Armstrong Flight Research Center to demonstrate the adaptive controller on a full-scale realistic application in a relevant flight environment. Concerns regarding adverse interactions between the adaptive controller and a proposed manual steering mode were investigated by giving the pilot trajectory deviation cues and pitch rate command authority.

  7. Study on the pressure self-adaptive water-tight junction box in underwater vehicle

    NASA Astrophysics Data System (ADS)

    Huang, Haocai; Ye, Yanying; Leng, Jianxing; Yuan, Zhuoli; Chen, Ying

    2012-09-01

    Underwater vehicles play a very important role in underwater engineering. Water-tight junction box (WJB) is one of the key components in underwater vehicle. This paper puts forward a pressure self-adaptive water-tight junction box (PSAWJB) which improves the reliability of the WJB significantly by solving the sealing and pressure problems in conventional WJB design. By redundancy design method, the pressure self-adaptive equalizer (PSAE) is designed in such a way that it consists of a piston pressure-adaptive compensator (PPAC) and a titanium film pressureadaptive compensator (TFPAC). According to hydro-mechanical simulations, the operating volume of the PSAE is more than or equal to 11.6 % of the volume of WJB liquid system. Furthermore, the required operating volume of the PSAE also increases as the gas content of oil, hydrostatic pressure or temperature difference increases. The reliability of the PSAWJB is proved by hyperbaric chamber tests

  8. Controls of maglev suspension systems

    SciTech Connect

    Cai, Y.; Zhu, S.; Chen, S.S.; Rote, D.M.

    1993-06-01

    This study investigates alternative control designs of maglev vehicle suspension systems. Active and semi-active control law designs are introduced into primary and secondary suspensions of maglev vehicles. A one-dimensional vehicle with two degrees of freedom, to simulate the German Transrapid Maglev System, is used for suspension control designs. The transient and frequency responses of suspension systems and PSDs of vehicle accelerations are calculated to evaluate different control designs. The results show that active and semi-active control designs indeed improve the response of vehicle and provide an acceptable ride comfort for maglev systems.

  9. Adaptation of bone and tendon to prolonged hindlimb suspension in rats

    NASA Technical Reports Server (NTRS)

    Vailas, Arthur C.; Deluna, Diane M.; Lewis, Lisa L.; Curwin, Sandra L.; Roy, Roland R.

    1988-01-01

    The effect of a sustained deprivation of ground reaction forces on mineralized and soft connective tissues was investigated in rats subjected to 28-d-long hind-limb suspension. The results of morphological and biochemical studies carried out on femurs and patellar tendons obtained from suspended and nonsuspended 110-d-old rats showed that prolonged suspension led to an increase of the minimum diameter of the femur middiaphysis (by 12 percent), without any significant alterations in cortical area, density, mineral and collagen concentrations, femur wet weight, length, and DNA and uronic acid concentrations. However, in the patellar tendons of suspended rats, the collagen and proteoglycan concentrations were 28 percent lower than in tendons obtained from nonsuspended animals. These results suggest that ground reaction forces are important for the maintenance of cortical bone and patellar tendon homeostasis during weight-bearing conditions.

  10. 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.

  11. Adaptive aerostructures: the first decade of flight on uninhabited aerial vehicles

    NASA Astrophysics Data System (ADS)

    Barrett, Ronald M.

    2004-07-01

    Although many subscale aircraft regularly fly with adaptive materials in sensors and small components in secondary subsystems, only a handful have flown with adaptive aerostructures as flight critical, enabling components. This paper reviews several families of adaptive aerostructures which have enabled or significantly enhanced flightworthy uninhabited aerial vehicles (UAVs), including rotary and fixed wing aircraft, missiles and munitions. More than 40 adaptive aerostructures programs which have had a direct connection to flight test and/or production UAVs, ranging from hover through hypersonic, sea-level to exo-stratospheric are examined. Adaptive material type, design Mach range, test methods, aircraft configuration and performance of each of the designs are presented. An historical analysis shows the evolution of flightworthy adaptive aerostructures from the earliest staggering flights in 1994 to modern adaptive UAVs supporting live-fire exercises in harsh military environments. Because there are profound differences between bench test, wind tunnel test, flight test and military grade flightworthy adaptive aerostructures, some of the most mature industrial design and fabrication techniques in use today will be outlined. The paper concludes with an example of the useful load and performance expansions which are seen on an industrial, military-grade UAV through the use of properly designed, flight-hardened adaptive aerostructures.

  12. On-line physical parameter identification and adaptive control of a launch vehicle

    NASA Astrophysics Data System (ADS)

    Keller, Brian Scott

    Physical parameter identification is useful in many applications, especially in aerospace where much analysis goes into developing accurate physical system models for control. A number of off-line physical parameter identification methods exist; however, the choice of on-line methods is more limited. On-line identification methods are required for adaptive control. New on-line physical parameter identification methods are developed in this work as motivated by the problem of launch vehicle adaptive control. Launch vehicles vary from launch to launch due to differences in payloads and fuel loading. Based on the known variations, launch vehicle control laws are reanalyzed and modified if necessary; this process is expensive and adds to recurring launch vehicle costs. This reanalysis is performed despite the fact that changes in the launch vehicle are relatively minor. A trustworthy adaptive control system could eliminate this expensive redesign cycle. An adaptive control system could also provide better performance than a controller redesigned off-line. However, adaptive control is still considered too risky to use with unstable systems, primarily due to limitations in the identification methods currently available for use in adaptive control. This problem is addressed with the development of new identification algorithms. A philosophy of identification is described which uses physical parameters for identification. A technique is developed to convert existing on-line methods to a form capable of identifying physical parameters. New methods include physical parameter versions of normalized least mean squares (NLMS), research least squares (RLS), extended least squares (ELS), recursive maximum likelihood (RML), and the extended Kalman filter (EKF). Compared to transfer function identification, physical parameter identification reduces the order of the problem and speeds up convergence. Compared to the extended Kalman filter, the new methods have a faster iteration

  13. 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.

  14. 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.

  15. Development and Flight Testing of an Adaptable Vehicle Health-Monitoring Architecture

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Coffey, Neil C.; Gonzalez, Guillermo A.; Woodman, Keith L.; Weathered, Brenton W.; Rollins, Courtney H.; Taylor, B. Douglas; Brett, Rube R.

    2003-01-01

    Development and testing of an adaptable wireless health-monitoring architecture for a vehicle fleet is presented. It has three operational levels: one or more remote data acquisition units located throughout the vehicle; a command and control unit located within the vehicle; and a terminal collection unit to collect analysis results from all vehicles. Each level is capable of performing autonomous analysis with a trained adaptable expert system. The remote data acquisition unit has an eight channel programmable digital interface that allows the user discretion for choosing type of sensors; number of sensors, sensor sampling rate, and sampling duration for each sensor. The architecture provides framework for a tributary analysis. All measurements at the lowest operational level are reduced to provide analysis results necessary to gauge changes from established baselines. These are then collected at the next level to identify any global trends or common features from the prior level. This process is repeated until the results are reduced at the highest operational level. In the framework, only analysis results are forwarded to the next level to reduce telemetry congestion. The system's remote data acquisition hardware and non-analysis software have been flight tested on the NASA Langley B757's main landing gear.

  16. 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.

  17. 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

  18. Fault Tolerance Analysis of L1 Adaptive Control System for Unmanned Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Krishnamoorthy, Kiruthika

    Trajectory tracking is a critical element for the better functionality of autonomous vehicles. The main objective of this research study was to implement and analyze L1 adaptive control laws for autonomous flight under normal and upset flight conditions. The West Virginia University (WVU) Unmanned Aerial Vehicle flight simulation environment was used for this purpose. A comparison study between the L1 adaptive controller and a baseline conventional controller, which relies on position, proportional, and integral compensation, has been performed for a reduced size jet aircraft, the WVU YF-22. Special attention was given to the performance of the proposed control laws in the presence of abnormal conditions. The abnormal conditions considered are locked actuators (stabilator, aileron, and rudder) and excessive turbulence. Several levels of abnormal condition severity have been considered. The performance of the control laws was assessed over different-shape commanded trajectories. A set of comprehensive evaluation metrics was defined and used to analyze the performance of autonomous flight control laws in terms of control activity and trajectory tracking errors. The developed L1 adaptive control laws are supported by theoretical stability guarantees. The simulation results show that L1 adaptive output feedback controller achieves better trajectory tracking with lower level of control actuation as compared to the baseline linear controller under nominal and abnormal conditions.

  19. Adaptive Automation for Human Supervision of Multiple Uninhabited Vehicles: Effects on Change Detection, Situation Awareness, and Mental Workload

    DTIC Science & Technology

    2009-01-01

    http://www.informaworld.com/smpp/title~content=t775653681 Adaptive Automation for Human Supervision of Multiple Uninhabited Vehicles: Effects on Change...Uninhabited Vehicles: Effects on Change Detection, Situation Awareness, and Mental Workload’,Military Psychology,21:2,270 — 297 To link to this...Supervision of Multiple Uninhabited Vehicles: Effects on Change Detection, Situation Awareness, and Mental Workload 5a. CONTRACT NUMBER 5b. GRANT

  20. Development and Flight Testing of an Adaptive Vehicle Health-Monitoring Architecture

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Coffey, Neil C.; Gonzalez, Guillermo A.; Taylor, B. Douglas; Brett, Rube R.; Woodman, Keith L.; Weathered, Brenton W.; Rollins, Courtney H.

    2002-01-01

    On going development and testing of an adaptable vehicle health-monitoring architecture is presented. The architecture is being developed for a fleet of vehicles. It has three operational levels: one or more remote data acquisition units located throughout the vehicle; a command and control unit located within the vehicle, and, a terminal collection unit to collect analysis results from all vehicles. Each level is capable of performing autonomous analysis with a trained expert system. The expert system is parameterized, which makes it adaptable to be trained to both a user's subject reasoning and existing quantitative analytic tools. Communication between all levels is done with wireless radio frequency interfaces. The remote data acquisition unit has an eight channel programmable digital interface that allows the user discretion for choosing type of sensors; number of sensors, sensor sampling rate and sampling duration for each sensor. The architecture provides framework for a tributary analysis. All measurements at the lowest operational level are reduced to provide analysis results necessary to gauge changes from established baselines. These are then collected at the next level to identify any global trends or common features from the prior level. This process is repeated until the results are reduced at the highest operational level. In the framework, only analysis results are forwarded to the next level to reduce telemetry congestion. The system's remote data acquisition hardware and non-analysis software have been flight tested on the NASA Langley B757's main landing gear. The flight tests were performed to validate the following: the wireless radio frequency communication capabilities of the system, the hardware design, command and control; software operation and, data acquisition, storage and retrieval.

  1. A robust adaptive nonlinear fault-tolerant controller via norm estimation for reusable launch vehicles

    NASA Astrophysics Data System (ADS)

    Hu, Chaofang; Gao, Zhifei; Ren, Yanli; Liu, Yunbing

    2016-11-01

    In this paper, a reusable launch vehicle (RLV) attitude control problem with actuator faults is addressed via the robust adaptive nonlinear fault-tolerant control (FTC) with norm estimation. Firstly, the accurate tracking task of attitude angles in the presence of parameter uncertainties and external disturbances is considered. A fault-free controller is proposed using dynamic surface control (DSC) combined with fuzzy adaptive approach. Furthermore, the minimal learning parameter strategy via norm estimation technique is introduced to reduce the multi-parameter adaptive computation burden of fuzzy approximation of the lump uncertainties. Secondly, a compensation controller is designed to handle the partial loss fault of actuator effectiveness. The unknown maximum eigenvalue of actuator efficiency loss factors is estimated online. Moreover, stability analysis guarantees that all signals of the closed-loop control system are semi-global uniformly ultimately bounded. Finally, illustrative simulations show the effectiveness of the proposed method.

  2. Verification and Tuning of an Adaptive Controller for an Unmanned Air Vehicle

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Matsutani, Megumi; Annaswamy, Anuradha M.

    2010-01-01

    This paper focuses on the analysis and tuning of a controller based on the Adaptive Control Technology for Safe Flight (ACTS) architecture. The ACTS architecture consists of a nominal, non-adaptive controller that provides satisfactory performance under nominal flying conditions, and an adaptive controller that provides robustness under off-nominal ones. A framework unifying control verification and gain tuning is used to make the controller s ability to satisfy the closed-loop requirements more robust to uncertainty. In this paper we tune the gains of both controllers using this approach. Some advantages and drawbacks of adaptation are identified by performing a global robustness assessment of both the adaptive controller and its non-adaptive counterpart. The analyses used to determine these characteristics are based on evaluating the degradation in closed-loop performance resulting from uncertainties having increasing levels of severity. The specific adverse conditions considered can be grouped into three categories: aerodynamic uncertainties, structural damage, and actuator failures. These failures include partial and total loss of control effectiveness, locked-in-place control surface deflections, and engine out conditions. The requirements considered are the peak structural loading, the ability of the controller to track pilot commands, the ability of the controller to keep the aircraft s state within the reliable flight envelope, and the handling/riding qualities of the aircraft. The nominal controller resulting from these tuning strategies was successfully validated using the NASA GTM Flight Test Vehicle.

  3. Finite Element Analysis of Folded Airbag in Frontal Impact of Adapted Vehicles for Disabled Drivers

    NASA Astrophysics Data System (ADS)

    Masiá, J.; Eixerés, B.; Dols, J. F.; Esquerdo, T. V.

    2009-11-01

    The car control adaptations are used in vehicles in order to facilitate the driving to persons with physical handicaps. This does not have to suppose a decrease of the passive safety that is required to the vehicles. In order to analyze this relation there will be characterized the different control adaptations that are in use together with the different devices of passive safety that can be mounted in the vehicles in diverse cases of impact in order to generate models of simulation. The methodology used to generate this simulation consists of the first phase in which there develops the three-dimensional model of the driving place. For it, there has been used a commercial software of three-dimensional design. Once realized this one divides, the model is imported to the finite elements software in which meshing is generated. Finally, dynamic simulation software is used to assign the most important characteristics like material properties, contact interfaces, gas expansion models, airbag fold types, etc.

  4. Adaptation of mobile ad-hoc network protocols for sensor networks to vehicle control applications

    NASA Astrophysics Data System (ADS)

    Sato, Kenya; Matsui, Yosuke; Koita, Takahiro

    2005-12-01

    As sensor network applications to monitor and control the physical environment from remote locations, a mobile ad-hoc network (MANET) has been the focus of many recent research and development efforts. A MANET, autonomous system of mobile hosts, is characterized by multi-hop wireless links, absence of any cellular infrastructure, and frequent host mobility. Many kinds of routing protocols for ad-hoc network have been proposed and still actively updated, because each application has different characteristics and requirements. Since the current studies show it is almost impossible to design an efficient routing protocol to be adapted for all kinds of applications. We, therefore, have focused a certain application, inter-vehicle communication for ITS (Intelligent Transport Systems), to evaluate the routing protocols. In our experiment, we defined several traffic flow models for inter-vehicle communication applications. By using simulation, we evaluated end-to-end delay and throughput performance of data transmission for inter-vehicle communications with the existing routing protocols. The result confirms the feasibility of using some routing protocols for inter-vehicle communication services.

  5. Adaptive neural control for cooperative path following of marine surface vehicles: state and output feedback

    NASA Astrophysics Data System (ADS)

    Wang, H.; Wang, D.; Peng, Z. H.

    2016-01-01

    This paper addresses the cooperative path-following problem of multiple marine surface vehicles subject to dynamical uncertainties and ocean disturbances induced by unknown wind, wave and ocean current. The control design falls neatly into two parts. One is to steer individual marine surface vehicle to track a predefined path and the other is to synchronise the along-path speed and path variables under the constraints of an underlying communication network. Within these two formulations, a robust adaptive path-following controller is first designed for individual vehicles based on backstepping and neural network techniques. Then, a decentralised synchronisation control law is derived by means of consensus on along-path speed and path variables based on graph theory. The distinct feature of this design lies in that synchronised path following can be reached for any undirected connected communication graphs without accurate knowledge of the model. This result is further extended to the output feedback case, where an observer-based cooperative path-following controller is developed without measuring the velocity of each vehicle. For both designs, rigorous theoretical analysis demonstrate that all signals in the closed-loop system are semi-global uniformly ultimately bounded. Simulation results validate the performance and robustness improvement of the proposed strategy.

  6. A memory structure adapted simulated annealing algorithm for a green vehicle routing problem.

    PubMed

    Küçükoğlu, İlker; Ene, Seval; Aksoy, Aslı; Öztürk, Nursel

    2015-03-01

    Currently, reduction of carbon dioxide (CO2) emissions and fuel consumption has become a critical environmental problem and has attracted the attention of both academia and the industrial sector. Government regulations and customer demands are making environmental responsibility an increasingly important factor in overall supply chain operations. Within these operations, transportation has the most hazardous effects on the environment, i.e., CO2 emissions, fuel consumption, noise and toxic effects on the ecosystem. This study aims to construct vehicle routes with time windows that minimize the total fuel consumption and CO2 emissions. The green vehicle routing problem with time windows (G-VRPTW) is formulated using a mixed integer linear programming model. A memory structure adapted simulated annealing (MSA-SA) meta-heuristic algorithm is constructed due to the high complexity of the proposed problem and long solution times for practical applications. The proposed models are integrated with a fuel consumption and CO2 emissions calculation algorithm that considers the vehicle technical specifications, vehicle load, and transportation distance in a green supply chain environment. The proposed models are validated using well-known instances with different numbers of customers. The computational results indicate that the MSA-SA heuristic is capable of obtaining good G-VRPTW solutions within a reasonable amount of time by providing reductions in fuel consumption and CO2 emissions.

  7. Vehicle Dynamics and Control

    NASA Astrophysics Data System (ADS)

    Rajamani, Rajesh

    Vehicle Dynamics and Control provides a comprehensive coverage of vehicle control systems and the dynamic models used in the development of these control systems. The control system topics covered in the book include cruise control, adaptive cruise control, ABS, automated lane keeping, automated highway systems, yaw stability control, engine control, passive, active and semi-active suspensions, tire models and tire-road friction estimation. In developing the dynamic model for each application, an effort is made to both keep the model simple enough for control system design but at the same time rich enough to capture the essential features of the dynamics.

  8. Sequential Insertion Heuristic with Adaptive Bee Colony Optimisation Algorithm for Vehicle Routing Problem with Time Windows.

    PubMed

    Jawarneh, Sana; Abdullah, Salwani

    2015-01-01

    This paper presents a bee colony optimisation (BCO) algorithm to tackle the vehicle routing problem with time window (VRPTW). The VRPTW involves recovering an ideal set of routes for a fleet of vehicles serving a defined number of customers. The BCO algorithm is a population-based algorithm that mimics the social communication patterns of honeybees in solving problems. The performance of the BCO algorithm is dependent on its parameters, so the online (self-adaptive) parameter tuning strategy is used to improve its effectiveness and robustness. Compared with the basic BCO, the adaptive BCO performs better. Diversification is crucial to the performance of the population-based algorithm, but the initial population in the BCO algorithm is generated using a greedy heuristic, which has insufficient diversification. Therefore the ways in which the sequential insertion heuristic (SIH) for the initial population drives the population toward improved solutions are examined. Experimental comparisons indicate that the proposed adaptive BCO-SIH algorithm works well across all instances and is able to obtain 11 best results in comparison with the best-known results in the literature when tested on Solomon's 56 VRPTW 100 customer instances. Also, a statistical test shows that there is a significant difference between the results.

  9. Sequential Insertion Heuristic with Adaptive Bee Colony Optimisation Algorithm for Vehicle Routing Problem with Time Windows

    PubMed Central

    Jawarneh, Sana; Abdullah, Salwani

    2015-01-01

    This paper presents a bee colony optimisation (BCO) algorithm to tackle the vehicle routing problem with time window (VRPTW). The VRPTW involves recovering an ideal set of routes for a fleet of vehicles serving a defined number of customers. The BCO algorithm is a population-based algorithm that mimics the social communication patterns of honeybees in solving problems. The performance of the BCO algorithm is dependent on its parameters, so the online (self-adaptive) parameter tuning strategy is used to improve its effectiveness and robustness. Compared with the basic BCO, the adaptive BCO performs better. Diversification is crucial to the performance of the population-based algorithm, but the initial population in the BCO algorithm is generated using a greedy heuristic, which has insufficient diversification. Therefore the ways in which the sequential insertion heuristic (SIH) for the initial population drives the population toward improved solutions are examined. Experimental comparisons indicate that the proposed adaptive BCO-SIH algorithm works well across all instances and is able to obtain 11 best results in comparison with the best-known results in the literature when tested on Solomon’s 56 VRPTW 100 customer instances. Also, a statistical test shows that there is a significant difference between the results. PMID:26132158

  10. The Joint Adaptive Kalman Filter (JAKF) for Vehicle Motion State Estimation

    PubMed Central

    Gao, Siwei; Liu, Yanheng; Wang, Jian; Deng, Weiwen; Oh, Heekuck

    2016-01-01

    This paper proposes a multi-sensory Joint Adaptive Kalman Filter (JAKF) through extending innovation-based adaptive estimation (IAE) to estimate the motion state of the moving vehicles ahead. JAKF views Lidar and Radar data as the source of the local filters, which aims to adaptively adjust the measurement noise variance-covariance (V-C) matrix ‘R’ and the system noise V-C matrix ‘Q’. Then, the global filter uses R to calculate the information allocation factor ‘β’ for data fusion. Finally, the global filter completes optimal data fusion and feeds back to the local filters to improve the measurement accuracy of the local filters. Extensive simulation and experimental results show that the JAKF has better adaptive ability and fault tolerance. JAKF enables one to bridge the gap of the accuracy difference of various sensors to improve the integral filtering effectivity. If any sensor breaks down, the filtered results of JAKF still can maintain a stable convergence rate. Moreover, the JAKF outperforms the conventional Kalman filter (CKF) and the innovation-based adaptive Kalman filter (IAKF) with respect to the accuracy of displacement, velocity, and acceleration, respectively. PMID:27438835

  11. The Joint Adaptive Kalman Filter (JAKF) for Vehicle Motion State Estimation.

    PubMed

    Gao, Siwei; Liu, Yanheng; Wang, Jian; Deng, Weiwen; Oh, Heekuck

    2016-07-16

    This paper proposes a multi-sensory Joint Adaptive Kalman Filter (JAKF) through extending innovation-based adaptive estimation (IAE) to estimate the motion state of the moving vehicles ahead. JAKF views Lidar and Radar data as the source of the local filters, which aims to adaptively adjust the measurement noise variance-covariance (V-C) matrix 'R' and the system noise V-C matrix 'Q'. Then, the global filter uses R to calculate the information allocation factor 'β' for data fusion. Finally, the global filter completes optimal data fusion and feeds back to the local filters to improve the measurement accuracy of the local filters. Extensive simulation and experimental results show that the JAKF has better adaptive ability and fault tolerance. JAKF enables one to bridge the gap of the accuracy difference of various sensors to improve the integral filtering effectivity. If any sensor breaks down, the filtered results of JAKF still can maintain a stable convergence rate. Moreover, the JAKF outperforms the conventional Kalman filter (CKF) and the innovation-based adaptive Kalman filter (IAKF) with respect to the accuracy of displacement, velocity, and acceleration, respectively.

  12. Adaptive Robust Online Constructive Fuzzy Control of a Complex Surface Vehicle System.

    PubMed

    Wang, Ning; Er, Meng Joo; Sun, Jing-Chao; Liu, Yan-Cheng

    2016-07-01

    In this paper, a novel adaptive robust online constructive fuzzy control (AR-OCFC) scheme, employing an online constructive fuzzy approximator (OCFA), to deal with tracking surface vehicles with uncertainties and unknown disturbances is proposed. Significant contributions of this paper are as follows: 1) unlike previous self-organizing fuzzy neural networks, the OCFA employs decoupled distance measure to dynamically allocate discriminable and sparse fuzzy sets in each dimension and is able to parsimoniously self-construct high interpretable T-S fuzzy rules; 2) an OCFA-based dominant adaptive controller (DAC) is designed by employing the improved projection-based adaptive laws derived from the Lyapunov synthesis which can guarantee reasonable fuzzy partitions; 3) closed-loop system stability and robustness are ensured by stable cancelation and decoupled adaptive compensation, respectively, thereby contributing to an auxiliary robust controller (ARC); and 4) global asymptotic closed-loop system can be guaranteed by AR-OCFC consisting of DAC and ARC and all signals are bounded. Simulation studies and comprehensive comparisons with state-of-the-arts fixed- and dynamic-structure adaptive control schemes demonstrate superior performance of the AR-OCFC in terms of tracking and approximation accuracy.

  13. A hybrid clustering based fuzzy structure for vibration control - Part 2: An application to semi-active vehicle seat-suspension system

    NASA Astrophysics Data System (ADS)

    Nguyen, Sy Dzung; Nguyen, Quoc Hung; Choi, Seung-Bok

    2015-05-01

    This work presents a novel neuro-fuzzy controller (NFC) for car-driver's seat-suspension system featuring magnetorheological (MR) dampers. The NFC is built based on the algorithm for building adaptive neuro-fuzzy inference systems (ANFISs) named B-ANFIS, which has been developed in Part 1, and fuzzy logic inference systems (FISs). In order to create the NFC, the following steps are performed. Firstly, a control strategy based on a ride-comfort-oriented tendency (RCOT) is established. Subsequently, optimal FISs are built based on a genetic algorithm (GA) to estimate the desired damping force that satisfies the RCOT corresponding to the road status at each time. The B-ANFIS is then used to build ANFISs for inverse dynamic models of the suspension system (I-ANFIS). Based on the FISs, the desired force values are calculated according to the status of road at each time. The corresponding exciting current value to be applied to the MR damper is then determined by the I-ANFIS. In order to validate the effectiveness of the developed neuro-fuzzy controller, control performances of the seat-suspension systems featuring MR dampers are evaluated under different road conditions. In addition, a comparative work between conventional skyhook controller and the proposed NFC is undertaken in order to demonstrate superior control performances of the proposed methodology.

  14. Fuzzy physical programming for Space Manoeuvre Vehicles trajectory optimization based on hp-adaptive pseudospectral method

    NASA Astrophysics Data System (ADS)

    Chai, Runqi; Savvaris, Al; Tsourdos, Antonios

    2016-06-01

    In this paper, a fuzzy physical programming (FPP) method has been introduced for solving multi-objective Space Manoeuvre Vehicles (SMV) skip trajectory optimization problem based on hp-adaptive pseudospectral methods. The dynamic model of SMV is elaborated and then, by employing hp-adaptive pseudospectral methods, the problem has been transformed to nonlinear programming (NLP) problem. According to the mission requirements, the solutions were calculated for each single-objective scenario. To get a compromised solution for each target, the fuzzy physical programming (FPP) model is proposed. The preference function is established with considering the fuzzy factor of the system such that a proper compromised trajectory can be acquired. In addition, the NSGA-II is tested to obtain the Pareto-optimal solution set and verify the Pareto optimality of the FPP solution. Simulation results indicate that the proposed method is effective and feasible in terms of dealing with the multi-objective skip trajectory optimization for the SMV.

  15. Adaptive frequency-separation-based energy management system for electric vehicles

    NASA Astrophysics Data System (ADS)

    Florescu, Adrian; Bacha, Seddik; Munteanu, Iulian; Bratcu, Antoneta Iuliana; Rumeau, Axel

    2015-04-01

    This paper deals with an adaptive frequency-based power sharing method between batteries and ultracapacitors (UC) as power sources within an electric vehicle. An adaptive frequency splitter is used for routing the low-frequency content of power demand into the battery and its high-frequency content into the UC system, taking profit from the UC as a peak power unit. Autonomy may thus be increased while preserving battery state of health and ensuring that UC voltage variations remain confined within certain desired range. Results obtained by real-time experiments on a dedicated test rig validate the proposed energy management approach and recommend it to be applied as power source coordination method to microgrids in general.

  16. Multi-vehicle detection with identity awareness using cascade Adaboost and Adaptive Kalman filter for driver assistant system.

    PubMed

    Wang, Baofeng; Qi, Zhiquan; Chen, Sizhong; Liu, Zhaodu; Ma, Guocheng

    2017-01-01

    Vision-based vehicle detection is an important issue for advanced driver assistance systems. In this paper, we presented an improved multi-vehicle detection and tracking method using cascade Adaboost and Adaptive Kalman filter(AKF) with target identity awareness. A cascade Adaboost classifier using Haar-like features was built for vehicle detection, followed by a more comprehensive verification process which could refine the vehicle hypothesis in terms of both location and dimension. In vehicle tracking, each vehicle was tracked with independent identity by an Adaptive Kalman filter in collaboration with a data association approach. The AKF adaptively adjusted the measurement and process noise covariance through on-line stochastic modelling to compensate the dynamics changes. The data association correctly assigned different detections with tracks using global nearest neighbour(GNN) algorithm while considering the local validation. During tracking, a temporal context based track management was proposed to decide whether to initiate, maintain or terminate the tracks of different objects, thus suppressing the sparse false alarms and compensating the temporary detection failures. Finally, the proposed method was tested on various challenging real roads, and the experimental results showed that the vehicle detection performance was greatly improved with higher accuracy and robustness.

  17. Multi-vehicle detection with identity awareness using cascade Adaboost and Adaptive Kalman filter for driver assistant system

    PubMed Central

    Wang, Baofeng; Qi, Zhiquan; Chen, Sizhong; Liu, Zhaodu; Ma, Guocheng

    2017-01-01

    Vision-based vehicle detection is an important issue for advanced driver assistance systems. In this paper, we presented an improved multi-vehicle detection and tracking method using cascade Adaboost and Adaptive Kalman filter(AKF) with target identity awareness. A cascade Adaboost classifier using Haar-like features was built for vehicle detection, followed by a more comprehensive verification process which could refine the vehicle hypothesis in terms of both location and dimension. In vehicle tracking, each vehicle was tracked with independent identity by an Adaptive Kalman filter in collaboration with a data association approach. The AKF adaptively adjusted the measurement and process noise covariance through on-line stochastic modelling to compensate the dynamics changes. The data association correctly assigned different detections with tracks using global nearest neighbour(GNN) algorithm while considering the local validation. During tracking, a temporal context based track management was proposed to decide whether to initiate, maintain or terminate the tracks of different objects, thus suppressing the sparse false alarms and compensating the temporary detection failures. Finally, the proposed method was tested on various challenging real roads, and the experimental results showed that the vehicle detection performance was greatly improved with higher accuracy and robustness. PMID:28296902

  18. Non-fragile multi-objective static output feedback control of vehicle active suspension with time-delay

    NASA Astrophysics Data System (ADS)

    Kong, Yongsu; Zhao, Dingxuan; Yang, Bin; Han, Chenghao; Han, Kyongwon

    2014-07-01

    This paper presents an approach to design a delay-dependent non-fragile H∞/L2-L∞ static output feedback (SOF) controller for active suspension with input time-delay. The control problem of quarter-car active suspension with actuator time-delay is formulated to a H∞/L2-L∞ control problem. By employing a delay-dependent Lyapunov function, new existence conditions of delay-dependent non-fragile SOF H∞ controller and L2-L∞ controller are derived, respectively, in terms of the feasibility of bilinear matrix inequalities (BMIs). Then, a procedure based on linear matrix inequality optimisation and a hybrid algorithm of the particle swarm optimisation and differential evolution is used to solve an optimisation problem with BMI constraints. Design and simulation results of non-fragile H∞/L2-L∞ controller for active suspension show that the designed controller not only can achieve the optimal performance and stability of the closed-loop system in spite of the existence of the actuator time-delay, but also has significantly improved the non-fragility characteristics over controller perturbations.

  19. Time course of muscular, neural and tendinous adaptations to 23 day unilateral lower-limb suspension in young men.

    PubMed

    de Boer, Maarten D; Maganaris, Constantinos N; Seynnes, Olivier R; Rennie, Michael J; Narici, Marco V

    2007-09-15

    Muscles and tendons are highly adaptive to changes in chronic loading, though little is known about the adaptative time course. We tested the hypothesis that, in response to unilateral lower limb suspension (ULLS), the magnitude of tendon mechanical adaptations would match or exceed those of skeletal muscle. Seventeen men (1.79 +/- 0.05 m, 76.6 +/- 10.3 kg, 22.3 +/- 3.8 years) underwent ULLS for 23 days (n = 9) or acted as controls (n = 8). Knee extensor (KE) torque, voluntary activation (VA), cross-sectional area (CSA) (by magnetic resonance imaging), vastus lateralis fascicle length (L(f)) and pennation angle (), patellar tendon stiffness and Young's modulus (by ultrasonography) were measured before, during and at the end of ULLS. After 14 and 23 days (i) KE torque decreased by 14.8 +/- 5.5% (P < 0.001) and 21.0 +/- 7.1% (P < 0.001), respectively; (ii) VA did not change; (iii) KE CSA decreased by 5.2 +/- 0.7% (P < 0.001) and 10.0 +/- 2.0% (P < 0.001), respectively; L(f) decreased by 5.9% (n.s.) and 7.7% (P < 0.05), respectively, and by 3.2% (P < 0.05) and 7.6% (P < 0.01); (iv) tendon stiffness decreased by 9.8 +/- 8.2% (P < 0.05) and 29.3 +/- 11.5% (P < 0.005), respectively, and Young's modulus by 9.2 +/- 8.2% (P < 0.05) and 30.1 +/- 11.9% (P < 0.01), respectively, with no changes in the controls. Hence, ULLS induces rapid losses of KE muscle size, architecture and function, but not in neural drive. Significant deterioration in tendon mechanical properties also occurs within 2 weeks, exacerbating in the third week of ULLS. Rehabilitation to limit muscle and tendon deterioration should probably start within 2 weeks of unloading.

  20. An Adaptive Numeric Predictor-corrector Guidance Algorithm for Atmospheric Entry Vehicles. M.S. Thesis - MIT, Cambridge

    NASA Technical Reports Server (NTRS)

    Spratlin, Kenneth Milton

    1987-01-01

    An adaptive numeric predictor-corrector guidance is developed for atmospheric entry vehicles which utilize lift to achieve maximum footprint capability. Applicability of the guidance design to vehicles with a wide range of performance capabilities is desired so as to reduce the need for algorithm redesign with each new vehicle. Adaptability is desired to minimize mission-specific analysis and planning. The guidance algorithm motivation and design are presented. Performance is assessed for application of the algorithm to the NASA Entry Research Vehicle (ERV). The dispersions the guidance must be designed to handle are presented. The achievable operational footprint for expected worst-case dispersions is presented. The algorithm performs excellently for the expected dispersions and captures most of the achievable footprint.

  1. An adaptive trajectory tracking control of four rotor hover vehicle using extended normalized radial basis function network

    NASA Astrophysics Data System (ADS)

    ul Amin, Rooh; Aijun, Li; Khan, Muhammad Umer; Shamshirband, Shahaboddin; Kamsin, Amirrudin

    2017-01-01

    In this paper, an adaptive trajectory tracking controller based on extended normalized radial basis function network (ENRBFN) is proposed for 3-degree-of-freedom four rotor hover vehicle subjected to external disturbance i.e. wind turbulence. Mathematical model of four rotor hover system is developed using equations of motions and a new computational intelligence based technique ENRBFN is introduced to approximate the unmodeled dynamics of the hover vehicle. The adaptive controller based on the Lyapunov stability approach is designed to achieve tracking of the desired attitude angles of four rotor hover vehicle in the presence of wind turbulence. The adaptive weight update based on the Levenberg-Marquardt algorithm is used to avoid weight drift in case the system is exposed to external disturbances. The closed-loop system stability is also analyzed using Lyapunov stability theory. Simulations and experimental results are included to validate the effectiveness of the proposed control scheme.

  2. Targeted Gene Deletion Using DNA-Free RNA-Guided Cas9 Nuclease Accelerates Adaptation of CHO Cells to Suspension Culture.

    PubMed

    Lee, Namil; Shin, JongOh; Park, Jin Hyoung; Lee, Gyun Min; Cho, Suhyung; Cho, Byung-Kwan

    2016-11-18

    Chinese hamster ovary (CHO) cells are the preferred host for the production of a wide array of biopharmaceuticals. Thus, efficient and rational CHO cell line engineering methods have been in high demand to improve quality and productivity. Here, we provide a novel genome engineering platform for increasing desirable phenotypes of CHO cells based upon the integrative protocol of high-throughput RNA sequencing and DNA-free RNA-guided Cas9 (CRISPR associated protein9) nuclease-based genome editing. For commercial production of therapeutic proteins, CHO cells have been adapted for suspension culture in serum-free media, which is highly beneficial with respect to productivity and economics. To engineer CHO cells for rapid adaptation to a suspension culture, we exploited strand-specific RNA-seq to identify genes differentially expressed according to their adaptation trajectory in serum-free media. More than 180 million sequencing reads were generated and mapped to the currently available 109,152 scaffolds of the CHO-K1 genome. We identified significantly downregulated genes according to the adaptation trajectory and then verified their effects using the genome editing method. Growth-based screening and targeted amplicon sequencing revealed that the functional deletions of Igfbp4 and AqpI gene accelerate suspension adaptation of CHO-K1 cells. The availability of this strand-specific transcriptome sequencing and DNA-free RNA-guided Cas9 nuclease mediated genome editing facilitates the rational design of the CHO cell genome for efficient production of high quality therapeutic proteins.

  3. Aeroelastic Deformation: Adaptation of Wind Tunnel Measurement Concepts to Full-Scale Vehicle Flight Testing

    NASA Technical Reports Server (NTRS)

    Burner, Alpheus W.; Lokos, William A.; Barrows, Danny A.

    2005-01-01

    The adaptation of a proven wind tunnel test technique, known as Videogrammetry, to flight testing of full-scale vehicles is presented. A description is presented of the technique used at NASA's Dryden Flight Research Center for the measurement of the change in wing twist and deflection of an F/A-18 research aircraft as a function of both time and aerodynamic load. Requirements for in-flight measurements are compared and contrasted with those for wind tunnel testing. The methodology for the flight-testing technique and differences compared to wind tunnel testing are given. Measurement and operational comparisons to an older in-flight system known as the Flight Deflection Measurement System (FDMS) are presented.

  4. Fair Energy Scheduling for Vehicle-to-Grid Networks Using Adaptive Dynamic Programming.

    PubMed

    Xie, Shengli; Zhong, Weifeng; Xie, Kan; Yu, Rong; Zhang, Yan

    2016-08-01

    Research on the smart grid is being given enormous supports worldwide due to its great significance in solving environmental and energy crises. Electric vehicles (EVs), which are powered by clean energy, are adopted increasingly year by year. It is predictable that the huge charge load caused by high EV penetration will have a considerable impact on the reliability of the smart grid. Therefore, fair energy scheduling for EV charge and discharge is proposed in this paper. By using the vehicle-to-grid technology, the scheduler controls the electricity loads of EVs considering fairness in the residential distribution network. We propose contribution-based fairness, in which EVs with high contributions have high priorities to obtain charge energy. The contribution value is defined by both the charge/discharge energy and the timing of the action. EVs can achieve higher contribution values when discharging during the load peak hours. However, charging during this time will decrease the contribution values seriously. We formulate the fair energy scheduling problem as an infinite-horizon Markov decision process. The methodology of adaptive dynamic programming is employed to maximize the long-term fairness by processing online network training. The numerical results illustrate that the proposed EV energy scheduling is able to mitigate and flatten the peak load in the distribution network. Furthermore, contribution-based fairness achieves a fast recovery of EV batteries that have deeply discharged and guarantee fairness in the full charge time of all EVs.

  5. Design Process of Flight Vehicle Structures for a Common Bulkhead and an MPCV Spacecraft Adapter

    NASA Technical Reports Server (NTRS)

    Aggarwal, Pravin; Hull, Patrick V.

    2015-01-01

    Design and manufacturing space flight vehicle structures is a skillset that has grown considerably at NASA during that last several years. Beginning with the Ares program and followed by the Space Launch System (SLS); in-house designs were produced for both the Upper Stage and the SLS Multipurpose crew vehicle (MPCV) spacecraft adapter. Specifically, critical design review (CDR) level analysis and flight production drawing were produced for the above mentioned hardware. In particular, the experience of this in-house design work led to increased manufacturing infrastructure for both Marshal Space Flight Center (MSFC) and Michoud Assembly Facility (MAF), improved skillsets in both analysis and design, and hands on experience in building and testing (MSA) full scale hardware. The hardware design and development processes from initiation to CDR and finally flight; resulted in many challenges and experiences that produced valuable lessons. This paper builds on these experiences of NASA in recent years on designing and fabricating flight hardware and examines the design/development processes used, as well as the challenges and lessons learned, i.e. from the initial design, loads estimation and mass constraints to structural optimization/affordability to release of production drawing to hardware manufacturing. While there are many documented design processes which a design engineer can follow, these unique experiences can offer insight into designing hardware in current program environments and present solutions to many of the challenges experienced by the engineering team.

  6. A self-adaptive memeplexes robust search scheme for solving stochastic demands vehicle routing problem

    NASA Astrophysics Data System (ADS)

    Chen, Xianshun; Feng, Liang; Ong, Yew Soon

    2012-07-01

    In this article, we proposed a self-adaptive memeplex robust search (SAMRS) for finding robust and reliable solutions that are less sensitive to stochastic behaviours of customer demands and have low probability of route failures, respectively, in vehicle routing problem with stochastic demands (VRPSD). In particular, the contribution of this article is three-fold. First, the proposed SAMRS employs the robust solution search scheme (RS 3) as an approximation of the computationally intensive Monte Carlo simulation, thus reducing the computation cost of fitness evaluation in VRPSD, while directing the search towards robust and reliable solutions. Furthermore, a self-adaptive individual learning based on the conceptual modelling of memeplex is introduced in the SAMRS. Finally, SAMRS incorporates a gene-meme co-evolution model with genetic and memetic representation to effectively manage the search for solutions in VRPSD. Extensive experimental results are then presented for benchmark problems to demonstrate that the proposed SAMRS serves as an efficable means of generating high-quality robust and reliable solutions in VRPSD.

  7. Stable production of a human growth hormone antagonist from CHO cells adapted to serum-free suspension culture.

    PubMed

    Haldankar, R; Kopchick, J J; Ridgway, D

    1999-01-01

    Human growth hormone (hGH) is a polypeptide with 191 amino acids and a molecular mass of 22 kDa. An hGH analogue was created with a single amino acid substitution (glycine[G] 120 to arginine[R]) in the third alpha-helix of the hGH molecule. This hGH analogue, named hGHG120R, was found to be an hGH antagonist. It is a parenteral drug candidate for treating conditions in which hGH levels are abnormally high, as found in type I diabetics. Previously, a genetically engineered anchorage-dependent mouse L cell line was created that produced and secreted hGHG120R in culture media (Dulbecco's modified Eagle's medium, DMEM) supplemented with 5% NuSerum IV. A multistep downstream process was developed to purify hGHG120R. The process consisted of cell clarification, salt precipitation, membrane ultrafiltration, size exclusion chromatography, reversed phase high-performance liquid chromatography, phase separation, and lyophilization. Here, we present the development of a superior eukaryotic system using a proper combination of genetic elements, cell line, and media formulation. This system is suitable for the large-scale production of the recombinant protein and is superior to the previously developed system in that it increases the specific production rate and at the same time eases the burden of the purification process, in both time and efficiency. Dihydrofolate reductase mutant (DHFR-) Chinese hamster ovary (CHO) cells were used that were stably transfected with an expression vector in which the hGHG120R gene is driven by the relatively strong human cytomegalovirus-early gene regulatory region. The hGHG120R tested to be biologically active. These cells were then adapted to grow in suspension in CHO-S-SFM (serum-free media). High cell densities, typically 2.0 x 10(6) cells/mL were obtained from spinner flask cultures. Partial purification of hGHG120R from CHO cell cultured media revealed that the level of impurities in SFM was significantly lower than the serum

  8. Physiological fitness and health adaptations from purposeful training using off-road vehicles.

    PubMed

    Burr, J F; Jamnik, V K; Gledhill, N

    2011-08-01

    The purpose of this study was to evaluate fitness and health adaptations from a training program riding all-terrain vehicles (ATV) and off-road motorcycles (ORM) as the exercise stimulus. Participants (n = 58) were randomized to a control group (n = 12) or one of four experimental groups; 2 days/week ATV (n = 11), 2 days/week ORM (n = 12), 4 days/week ATV (n = 11), or 4 days/week ORM (n = 12). Aerobic fitness, musculoskeletal fitness, body composition, clinical health, and quality of life (QOL) were compared at baseline and following 6 weeks of training. In all riding groups, there were improvements in blood pressure (SBP = 9.4 ± 10.1, DBP = 5.8 ± 6.2 mmHg), fasting glucose (0.5 ± 0.7 mmol/l), subcutaneous adiposity (0.9 ± 1.1%), body mass (0.7 ± 2.7 kg), waist circumference (1.3 ± 2.5 cm), and isometric leg endurance (26 ± 44 s). All changes were of moderate to large magnitude (Cohen's d 0.52-0.94) with the exception of a small loss of body mass (Cohen's d = 0.27). Although changes occurred in the riding groups for aerobic power (2.9 ± 4.6 ml kg(-1) min(-1)), leg power (172 ± 486 w), and curl-ups (13.2 ± 22.7), these changes were not significantly different from the control group. No significant alterations occurred in resting heart rate, trunk flexibility, back endurance, hand grip strength, long jump, pull/push strength, or push-up ability as a result of training. Physical domain QOL increased in all 2 days/week riders but mental domain QOL increased in all ORM, but not ATV riders regardless of volume. Ambient carbon monoxide levels while riding (<30 ppm) were within safe exposure guidelines. Positive adaptations can be gained from a training program using off-road vehicle riding as the exercise stimulus.

  9. Friction Stir Weld Application and Tooling Design for the Multi-purpose Crew Vehicle Stage Adapter

    NASA Technical Reports Server (NTRS)

    Alcorn, John

    2013-01-01

    The Multi-Purpose Crew Vehicle (MPCV), commonly known as the Orion capsule, is planned to be the United States' next manned spacecraft for missions beyond low earth orbit. Following the cancellation of the Constellation program and creation of SLS (Space Launch System), the need arose for the MPCV to utilize the Delta IV Heavy rocket for a test launch scheduled for 2014 instead of the previously planned Ares I rocket. As a result, an adapter (MSA) must be used in conjunction with the MPCV to account for the variation in diameter of the launch vehicles; 5.5 meters down to 5.0 meters. Prior to ight article fabrication, a path nder (test article) will be fabricated to ne tune the associated manufacturing processes. The adapter will be comprised of an aluminum frustum (partial cone) that employs isogrid technology and circumferential rings on each end. The frustum will be fabricated by friction stir welding (FSW) three individual panels together on a Vertical Weld Tool (VWT) at NASA Marshall Space Flight Center. Subsequently, each circumferential ring will be friction stir welded to the frustum using a Robotic Weld Tool (RWT). The irregular geometry and large mass of the MSA require that extensive tooling preparation be put into support structures for the friction stir weld. The tooling on the VWT will be comprised of a set of conveyors mounted on pre-existing stanchions so that the MSA will have the ability to be rotated after each of the three friction stir welds. The tooling requirements to friction stir weld the rings with the RWT are somewhat more demanding. To support the mass of the MSA and resist the load of the weld tool, a system of mandrels will be mounted to stanchions and assembled in a circle. The goal of the paper will be to explain the design, fabrication, and assembly of the tooling, to explain the use of friction stir welding on the MSA path nder, and also to discuss the lessons learned and modi cations made in preparation for ight article fabrication

  10. 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.

  11. Human-Automation Interaction Design for Adaptive Cruise Control Systems of Ground Vehicles.

    PubMed

    Eom, Hwisoo; Lee, Sang Hun

    2015-06-12

    A majority of recently developed advanced vehicles have been equipped with various automated driver assistance systems, such as adaptive cruise control (ACC) and lane keeping assistance systems. ACC systems have several operational modes, and drivers can be unaware of the mode in which they are operating. Because mode confusion is a significant human error factor that contributes to traffic accidents, it is necessary to develop user interfaces for ACC systems that can reduce mode confusion. To meet this requirement, this paper presents a new human-automation interaction design methodology in which the compatibility of the machine and interface models is determined using the proposed criteria, and if the models are incompatible, one or both of the models is/are modified to make them compatible. To investigate the effectiveness of our methodology, we designed two new interfaces by separately modifying the machine model and the interface model and then performed driver-in-the-loop experiments. The results showed that modifying the machine model provides a more compact, acceptable, effective, and safe interface than modifying the interface model.

  12. Economy-oriented vehicle adaptive cruise control with coordinating multiple objectives function

    NASA Astrophysics Data System (ADS)

    Eben Li, Shengbo; Li, Keqiang; Wang, Jianqiang

    2013-01-01

    A recent design issue of adaptive cruise control systems is how to reduce fuel consumption when following a preceding vehicle. High fuel economy is achievable through reducing acceleration level, however, it is also significantly restrained by two other functional demands, track capability and driver desired response. In the framework of multi-objective coordination, this paper develops and experimentally validates an economy-oriented headway control algorithm for a passenger car with internal combustion engine. The control algorithm is synthesised in a hierarchical structure. The upper controller, undertaking a major coordinating task, is designed based on the model predictive control theory. Fuel economy, tracking capability, and the driver desired response are formulated as its cost function and constraints in a finite prediction horizon. As further analysis indicated, such a design inevitably results in infeasible control inputs in some extreme cases, e.g. urgent situations involving rapid acceleration/deceleration. A constraint softening method is adopted to enlarge the feasible region in the cost of somewhat sacrificing the optimality of the original cost function. Finally, a prototyping controller is developed based on xPC toolbox and equipped in a passenger car. The followed field tests show that, compared to a linear quadratic controller, such an algorithm improves both fuel economy and tracking capability while also being more responsive to driver car-following behaviours.

  13. Human-Automation Interaction Design for Adaptive Cruise Control Systems of Ground Vehicles

    PubMed Central

    Eom, Hwisoo; Lee, Sang Hun

    2015-01-01

    A majority of recently developed advanced vehicles have been equipped with various automated driver assistance systems, such as adaptive cruise control (ACC) and lane keeping assistance systems. ACC systems have several operational modes, and drivers can be unaware of the mode in which they are operating. Because mode confusion is a significant human error factor that contributes to traffic accidents, it is necessary to develop user interfaces for ACC systems that can reduce mode confusion. To meet this requirement, this paper presents a new human-automation interaction design methodology in which the compatibility of the machine and interface models is determined using the proposed criteria, and if the models are incompatible, one or both of the models is/are modified to make them compatible. To investigate the effectiveness of our methodology, we designed two new interfaces by separately modifying the machine model and the interface model and then performed driver-in-the-loop experiments. The results showed that modifying the machine model provides a more compact, acceptable, effective, and safe interface than modifying the interface model. PMID:26076406

  14. An adaptive remaining energy prediction approach for lithium-ion batteries in electric vehicles

    NASA Astrophysics Data System (ADS)

    Wang, Yujie; Zhang, Chenbin; Chen, Zonghai

    2016-02-01

    With the growing number of electric vehicle (EV) applications, the function of the battery management system (BMS) becomes more sophisticated. The accuracy of remaining energy estimation is critical for energy optimization and management in EVs. Therefore the state-of-energy (SoE) is defined to indicate the remaining available energy of the batteries. Considering that there are inevitable accumulated errors caused by current and voltage integral method, an adaptive SoE estimator is first established in this paper. In order to establish a reasonable battery equivalent model, based on the experimental data of the LiFePO4 battery, a data-driven model is established to describe the relationship between the open-circuit voltage (OCV) and the SoE. What is more, the forgetting factor recursive least-square (RLS) method is used for parameter identification to get accurate model parameters. Finally, in order to analyze the robustness and the accuracy of the proposed approach, different types of dynamic current profiles are conducted on the lithium-ion batteries and the performances are calculated and compared. The results indicate that the proposed approach has robust and accurate SoE estimation results under dynamic working conditions.

  15. Articulated Suspension Without Springs

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.

    1990-01-01

    Wheels negotiate bumps and holes with minimal tilting of vehicle body. In new suspension, wheel climbs obstacle as high as 1 1/2 times its diameter without excessive tilting of chassis. Provides highly stable ride over rough ground for such vehicles as wheelchairs, military scout cars, and police and fire robots. System of levers distributes weight to wheels. Sized to distribute equal or other desired portions of load among wheels.

  16. Launch Vehicle Manual Steering with Adaptive Augmenting Control In-flight Evaluations of Adverse Interactions Using a Piloted Aircraft

    NASA Technical Reports Server (NTRS)

    Hanson, Curt; Miller, Chris; Wall, John H.; Vanzwieten, Tannen S.; Gilligan, Eric; Orr, Jeb S.

    2015-01-01

    An adaptive augmenting control algorithm for the Space Launch System has been developed at the Marshall Space Flight Center as part of the launch vehicles baseline flight control system. A prototype version of the SLS flight control software was hosted on a piloted aircraft at the Armstrong Flight Research Center to demonstrate the adaptive controller on a full-scale realistic application in a relevant flight environment. Concerns regarding adverse interactions between the adaptive controller and a proposed manual steering mode were investigated by giving the pilot trajectory deviation cues and pitch rate command authority. Two NASA research pilots flew a total of twenty five constant pitch-rate trajectories using a prototype manual steering mode with and without adaptive control.

  17. Accurate Attitude Estimation Using ARS under Conditions of Vehicle Movement Based on Disturbance Acceleration Adaptive Estimation and Correction

    PubMed Central

    Xing, Li; Hang, Yijun; Xiong, Zhi; Liu, Jianye; Wan, Zhong

    2016-01-01

    This paper describes a disturbance acceleration adaptive estimate and correction approach for an attitude reference system (ARS) so as to improve the attitude estimate precision under vehicle movement conditions. The proposed approach depends on a Kalman filter, where the attitude error, the gyroscope zero offset error and the disturbance acceleration error are estimated. By switching the filter decay coefficient of the disturbance acceleration model in different acceleration modes, the disturbance acceleration is adaptively estimated and corrected, and then the attitude estimate precision is improved. The filter was tested in three different disturbance acceleration modes (non-acceleration, vibration-acceleration and sustained-acceleration mode, respectively) by digital simulation. Moreover, the proposed approach was tested in a kinematic vehicle experiment as well. Using the designed simulations and kinematic vehicle experiments, it has been shown that the disturbance acceleration of each mode can be accurately estimated and corrected. Moreover, compared with the complementary filter, the experimental results have explicitly demonstrated the proposed approach further improves the attitude estimate precision under vehicle movement conditions. PMID:27754469

  18. Non-Maximally Decimated Filter Banks Enable Adaptive Frequency Hopping for Unmanned Aircraft Vehicles

    NASA Technical Reports Server (NTRS)

    Venosa, Elettra; Vermeire, Bert; Alakija, Cameron; Harris, Fred; Strobel, David; Sheehe, Charles J.; Krunz, Marwan

    2017-01-01

    In the last few years, radio technologies for unmanned aircraft vehicle (UAV) have advanced very rapidly. The increasing need to fly unmanned aircraft systems (UAS) in the national airspace system (NAS) to perform missions of vital importance to national security, defense, and science has pushed ahead the design and implementation of new radio platforms. However, a lot still has to be done to improve those radios in terms of performance and capabilities. In addition, an important aspect to account for is hardware cost and the feasibility to implement these radios using commercial off-the-shelf (COTS) components. UAV radios come with numerous technical challenges and their development involves contributions at different levels of the design. Cognitive algorithms need to be developed in order to perform agile communications using appropriate frequency allocation while maintaining safe and efficient operations in the NAS and, digital reconfigurable architectures have to be designed in order to ensure a prompt response to environmental changes. Command and control (C2) communications have to be preserved during "standard" operations while crew operations have to be minimized. It is clear that UAV radios have to be software-defined systems, where size, weight and power consumption (SWaP) are critical parameters. This paper provides preliminary results of the efforts performed to design a fully digital radio architecture as part of a NASA Phase I STTR. In this paper, we will explain the basic idea and technical principles behind our dynamic/adaptive frequency hopping radio for UAVs. We will present our Simulink model of the dynamic FH radio transmitter design for UAV communications and show simulation results and FPGA system analysis.

  19. Path Tracking for Unmanned Ground Vehicle Navigation: Implementation and Adaptation of the Pure Pursuit Algorithm

    DTIC Science & Technology

    2005-12-01

    a user for a patrol mission. To increase the vehicle’s abilities, other behaviours such as obstacle avoidance, path planning or leader / follower augment...15 5.4 Leader / Follower Behaviour . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 5.5 Waypoint Following...Navigation Behaviour - Provide goal directedness in concert with an obstacle avoid- ance algorithm. 3. Leader / Follower - Allow a follower vehicle to

  20. Independent wheel suspension system using thrust bearing constant velocity universal drive joints as suspension members to minimize wheel chamber

    SciTech Connect

    Krude, W.

    1986-12-30

    An independent wheel suspension system is described for a vehicle having an engine adapted to provide a driving torque, a chassis, vehicle support means for resiliently supporting the chassis for displacement relative to a driving surface, and a wheel assembly for each wheel having a vertical center plane through the center thereof and a wheel axis substantially perpendicular to the vertical center plane. The wheel assembly has a chamber angle relative to the vertical center plane adapted to undergo a change of chamber as the wheel assembly undergoes movement relative to the vertical center plane. The independent wheel suspension system comprises: differential means comprising a differential housing, a differential input at an engine end of the differential housing adapted to be coupled to the engine so as to receive the driving torque therefrom about a differential input axis. The differential housing has a pair of lateral sides on opposite sides of the differential input axis, each lateral side having a differential output axis therethrough. The differential means is adapted to redirect the driving torque from the differential input axis to the differential output axis and is supported by the vehicle support means to position the differential input axis substantially perpendicular to the wheel axis.

  1. Development of Micro Air Vehicle Technology With In-Flight Adaptive-Wing Structure

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R. (Technical Monitor); Shkarayev, Sergey; Null, William; Wagner, Matthew

    2004-01-01

    This is a final report on the research studies, "Development of Micro Air Vehicle Technology with In-Flight Adaptrive-Wing Structure". This project involved the development of variable-camber technology to achieve efficient design of micro air vehicles. Specifically, it focused on the following topics: 1) Low Reynolds number wind tunnel testing of cambered-plate wings. 2) Theoretical performance analysis of micro air vehicles. 3) Design of a variable-camber MAV actuated by micro servos. 4) Test flights of a variable-camber MAV.

  2. The effects of mechanical response on the dynamics and string stability of a platoon of adaptive cruise control vehicles

    NASA Astrophysics Data System (ADS)

    Davis, L. C.

    2013-09-01

    The dynamics of a platoon of adaptive cruise control vehicles is analyzed for a general mechanical response of the vehicle. Effects of acceleration-feedback control that were not previously studied are found. For small acceleration-feedback gain, which produces marginally string-stable behavior, the reduction of a disturbance (with increasing car number n) is found to be faster than for the maximum allowable gain. The asymptotic magnitude of a disturbance is shown to fall off as erf({ct.}/{√n}) when n→∞. For gain approaching the lower limit of stability, oscillations in acceleration associated with a secondary maximum in the transfer function (as a function of frequency) can occur. A frequency-dependent gain that reduces the secondary maximum, but does not affect the transfer function near zero frequency, is proposed. Performance is thereby improved by elimination of the undesirable oscillations while the rapid disturbance reduction is retained.

  3. Real-Time Dynamic Model Learning and Adaptation for Underwater Vehicles

    DTIC Science & Technology

    2013-09-01

    a variety of sensors including a controllable HD camera, rear and side cameras, sonars, as well as a grabber arm for in- water intervention. A...platforms, coastal and inshore surveys, maritime security of ports, harbors and vessels, or long line penetration or pipe 9 inspections. The vehicle...than the water line, the vehicle assumed a negative pitch (downward) angle during every test. This resulted in the aft pair of thrusters being up to

  4. Adaptive and Distributed Algorithms for Vehicle Routing in a Stochastic and Dynamic Environment

    DTIC Science & Technology

    2010-11-18

    stochastic and dynamic vehicle routing problems,” PhD Thesis, Dept. of Civil and Environmental Engineering , Massachusetts Institute of Technology ... Technology (MIT), Cam- bridge, in 2001. From 2001 to 2004, he was an Assistant Professor of aerospace engineering at the University of Illinois at Urbana...system. The general problem is known as the m-vehicle Dynamic Traveling Repairman Problem (m-DTRP). The best previously known con- trol algorithms rely on

  5. An adaptable, low cost test-bed for unmanned vehicle systems research

    NASA Astrophysics Data System (ADS)

    Goppert, James M.

    2011-12-01

    An unmanned vehicle systems test-bed has been developed. The test-bed has been designed to accommodate hardware changes and various vehicle types and algorithms. The creation of this test-bed allows research teams to focus on algorithm development and employ a common well-tested experimental framework. The ArduPilotOne autopilot was developed to provide the necessary level of abstraction for multiple vehicle types. The autopilot was also designed to be highly integrated with the Mavlink protocol for Micro Air Vehicle (MAV) communication. Mavlink is the native protocol for QGroundControl, a MAV ground control program. Features were added to QGroundControl to accommodate outdoor usage. Next, the Mavsim toolbox was developed for Scicoslab to allow hardware-in-the-loop testing, control design and analysis, and estimation algorithm testing and verification. In order to obtain linear models of aircraft dynamics, the JSBSim flight dynamics engine was extended to use a probabilistic Nelder-Mead simplex method. The JSBSim aircraft dynamics were compared with wind-tunnel data collected. Finally, a structured methodology for successive loop closure control design is proposed. This methodology is demonstrated along with the rest of the test-bed tools on a quadrotor, a fixed wing RC plane, and a ground vehicle. Test results for the ground vehicle are presented.

  6. Generation and Adaptation of Transferable Roadway Model for Anticipative Road Following on Satellite-Roadway-Vehicle Network

    NASA Astrophysics Data System (ADS)

    Kamejima, Kohji

    By matching roadway images in an encountered scene with bird's eye views, the scope of humans' perception is expanded to a satellite-roadway-vehicle network. Based on the geometric consistency of the satellite images with as-is local terrain, in this paper, a computational mechanism is introduced for generation and adaptation of a roadway model transferable through the network. First, the chromatic complexity of the roadway area is represented as a palette of saliency colors via fractal sampling of the scene image. Next, the palette is adapted to the associated area in the bird's eye view. Finally, the palette is transferred to the bird's eye view for anticipatively following the roadway pattern. Experimental results demonstrate that the transferable model can be applied to the extension of the roadway pattern prior to physical access.

  7. L(sub 1) Adaptive Control Design for NASA AirSTAR Flight Test Vehicle

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.; Cao, Chengyu; Hovakimyan, Naira; Zou, Xiaotian

    2009-01-01

    In this paper we present a new L(sub 1) adaptive control architecture that directly compensates for matched as well as unmatched system uncertainty. To evaluate the L(sub 1) adaptive controller, we take advantage of the flexible research environment with rapid prototyping and testing of control laws in the Airborne Subscale Transport Aircraft Research system at the NASA Langley Research Center. We apply the L(sub 1) adaptive control laws to the subscale turbine powered Generic Transport Model. The presented results are from a full nonlinear simulation of the Generic Transport Model and some preliminary pilot evaluations of the L(sub 1) adaptive control law.

  8. Probabilistic Sensitivity Analysis for Launch Vehicles with Varying Payloads and Adapters for Structural Dynamics and Loads

    NASA Technical Reports Server (NTRS)

    McGhee, David S.; Peck, Jeff A.; McDonald, Emmett J.

    2012-01-01

    This paper examines Probabilistic Sensitivity Analysis (PSA) methods and tools in an effort to understand their utility in vehicle loads and dynamic analysis. Specifically, this study addresses how these methods may be used to establish limits on payload mass and cg location and requirements on adaptor stiffnesses while maintaining vehicle loads and frequencies within established bounds. To this end, PSA methods and tools are applied to a realistic, but manageable, integrated launch vehicle analysis where payload and payload adaptor parameters are modeled as random variables. This analysis is used to study both Regional Response PSA (RRPSA) and Global Response PSA (GRPSA) methods, with a primary focus on sampling based techniques. For contrast, some MPP based approaches are also examined.

  9. Launch Vehicle Manual Steering with Adaptive Augmenting Control:In-Flight Evaluations of Adverse Interactions Using a Piloted Aircraft

    NASA Technical Reports Server (NTRS)

    Hanson, Curt; Miller, Chris; Wall, John H.; VanZwieten, Tannen S.; Gilligan, Eric T.; Orr, Jeb S.

    2015-01-01

    An Adaptive Augmenting Control (AAC) algorithm for the Space Launch System (SLS) has been developed at the Marshall Space Flight Center (MSFC) as part of the launch vehicle's baseline flight control system. A prototype version of the SLS flight control software was hosted on a piloted aircraft at the Armstrong Flight Research Center to demonstrate the adaptive controller on a full-scale realistic application in a relevant flight environment. Concerns regarding adverse interactions between the adaptive controller and a potential manual steering mode were also investigated by giving the pilot trajectory deviation cues and pitch rate command authority, which is the subject of this paper. Two NASA research pilots flew a total of 25 constant pitch rate trajectories using a prototype manual steering mode with and without adaptive control, evaluating six different nominal and off-nominal test case scenarios. Pilot comments and PIO ratings were given following each trajectory and correlated with aircraft state data and internal controller signals post-flight.

  10. An adaptive large neighborhood search heuristic for Two-Echelon Vehicle Routing Problems arising in city logistics.

    PubMed

    Hemmelmayr, Vera C; Cordeau, Jean-François; Crainic, Teodor Gabriel

    2012-12-01

    In this paper, we propose an adaptive large neighborhood search heuristic for the Two-Echelon Vehicle Routing Problem (2E-VRP) and the Location Routing Problem (LRP). The 2E-VRP arises in two-level transportation systems such as those encountered in the context of city logistics. In such systems, freight arrives at a major terminal and is shipped through intermediate satellite facilities to the final customers. The LRP can be seen as a special case of the 2E-VRP in which vehicle routing is performed only at the second level. We have developed new neighborhood search operators by exploiting the structure of the two problem classes considered and have also adapted existing operators from the literature. The operators are used in a hierarchical scheme reflecting the multi-level nature of the problem. Computational experiments conducted on several sets of instances from the literature show that our algorithm outperforms existing solution methods for the 2E-VRP and achieves excellent results on the LRP.

  11. Novel adaptive neural control design for a constrained flexible air-breathing hypersonic vehicle based on actuator compensation

    NASA Astrophysics Data System (ADS)

    Bu, Xiangwei; Wu, Xiaoyan; He, Guangjun; Huang, Jiaqi

    2016-03-01

    This paper investigates the design of a novel adaptive neural controller for the longitudinal dynamics of a flexible air-breathing hypersonic vehicle with control input constraints. To reduce the complexity of controller design, the vehicle dynamics is decomposed into the velocity subsystem and the altitude subsystem, respectively. For each subsystem, only one neural network is utilized to approach the lumped unknown function. By employing a minimal-learning parameter method to estimate the norm of ideal weight vectors rather than their elements, there are only two adaptive parameters required for neural approximation. Thus, the computational burden is lower than the ones derived from neural back-stepping schemes. Specially, to deal with the control input constraints, additional systems are exploited to compensate the actuators. Lyapunov synthesis proves that all the closed-loop signals involved are uniformly ultimately bounded. Finally, simulation results show that the adopted compensation scheme can tackle actuator constraint effectively and moreover velocity and altitude can stably track their reference trajectories even when the physical limitations on control inputs are in effect.

  12. An adaptive large neighborhood search heuristic for Two-Echelon Vehicle Routing Problems arising in city logistics

    PubMed Central

    Hemmelmayr, Vera C.; Cordeau, Jean-François; Crainic, Teodor Gabriel

    2012-01-01

    In this paper, we propose an adaptive large neighborhood search heuristic for the Two-Echelon Vehicle Routing Problem (2E-VRP) and the Location Routing Problem (LRP). The 2E-VRP arises in two-level transportation systems such as those encountered in the context of city logistics. In such systems, freight arrives at a major terminal and is shipped through intermediate satellite facilities to the final customers. The LRP can be seen as a special case of the 2E-VRP in which vehicle routing is performed only at the second level. We have developed new neighborhood search operators by exploiting the structure of the two problem classes considered and have also adapted existing operators from the literature. The operators are used in a hierarchical scheme reflecting the multi-level nature of the problem. Computational experiments conducted on several sets of instances from the literature show that our algorithm outperforms existing solution methods for the 2E-VRP and achieves excellent results on the LRP. PMID:23483764

  13. Parallel, Gradient-Based Anisotropic Mesh Adaptation for Re-entry Vehicle Configurations

    NASA Technical Reports Server (NTRS)

    Bibb, Karen L.; Gnoffo, Peter A.; Park, Michael A.; Jones, William T.

    2006-01-01

    Two gradient-based adaptation methodologies have been implemented into the Fun3d refine GridEx infrastructure. A spring-analogy adaptation which provides for nodal movement to cluster mesh nodes in the vicinity of strong shocks has been extended for general use within Fun3d, and is demonstrated for a 70 sphere cone at Mach 2. A more general feature-based adaptation metric has been developed for use with the adaptation mechanics available in Fun3d, and is applicable to any unstructured, tetrahedral, flow solver. The basic functionality of general adaptation is explored through a case of flow over the forebody of a 70 sphere cone at Mach 6. A practical application of Mach 10 flow over an Apollo capsule, computed with the Felisa flow solver, is given to compare the adaptive mesh refinement with uniform mesh refinement. The examples of the paper demonstrate that the gradient-based adaptation capability as implemented can give an improvement in solution quality.

  14. Design of a Model Reference Adaptive Controller for an Unmanned Air Vehicle

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Matsutani, Megumi; Annaswamy, Anuradha M.

    2010-01-01

    This paper presents the "Adaptive Control Technology for Safe Flight (ACTS)" architecture, which consists of a non-adaptive controller that provides satisfactory performance under nominal flying conditions, and an adaptive controller that provides robustness under off nominal ones. The design and implementation procedures of both controllers are presented. The aim of these procedures, which encompass both theoretical and practical considerations, is to develop a controller suitable for flight. The ACTS architecture is applied to the Generic Transport Model developed by NASA-Langley Research Center. The GTM is a dynamically scaled test model of a transport aircraft for which a flight-test article and a high-fidelity simulation are available. The nominal controller at the core of the ACTS architecture has a multivariable LQR-PI structure while the adaptive one has a direct, model reference structure. The main control surfaces as well as the throttles are used as control inputs. The inclusion of the latter alleviates the pilot s workload by eliminating the need for cancelling the pitch coupling generated by changes in thrust. Furthermore, the independent usage of the throttles by the adaptive controller enables their use for attitude control. Advantages and potential drawbacks of adaptation are demonstrated by performing high fidelity simulations of a flight-validated controller and of its adaptive augmentation.

  15. Stability study of oral pediatric idebenone suspensions.

    PubMed

    Schlatter, Joël; Bourguignon, Elodie; Majoul, Elyes; Kabiche, Sofiane; Balde, Issa-Bella; Cisternino, Salvatore; Fontan, Jean-Eudes

    2017-03-01

    Adapted forms for administration to infants are limited. The proposed study was performed to propose oral liquid formulations of idebenone in Ora-Plus and either Ora-Sweet or Ora-Sweet SF, Ora-Blend, Ora-Blend SF and Inorpha. Each formulation was stored in 30 ml amber glass bottle at 5 or 25 °C for 90 days. Idebenone contents in these suspensions, determined by a stability-indicating high-performance liquid chromatography method, remained stable at least 90 days in Inorpha when stored at the two temperatures. In Ora-Blend, the stability was estimated at 14 days and in other suspensions at 20 days at the two temperatures. After 90 days storage, the pH of Ora-Plus and Ora-Sweet or Ora-Sweet SF changed between -0.10 and -0.25 units. For others suspensions, the pH changes were not significant (< -0.09 unit). No change was observed in color, odor or visual microbiology. To conclude, we recommended the use of idebenone in Inorpha vehicle stable for at least 90 days at 25 °C.

  16. Self-Aware Vehicles: Mission and Performance Adaptation to System Health

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.; Leonard, Charles; Scotti, Stephen J.

    2016-01-01

    Advances in sensing (miniaturization, distributed sensor networks) combined with improvements in computational power leading to significant gains in perception, real-time decision making/reasoning and dynamic planning under uncertainty as well as big data predictive analysis have set the stage for realization of autonomous system capability. These advances open the design and operating space for self-aware vehicles that are able to assess their own capabilities and adjust their behavior to either complete the assigned mission or to modify the mission to reflect their current capabilities. This paper discusses the self-aware vehicle concept and associated technologies necessary for full exploitation of the concept. A self-aware aircraft, spacecraft or system is one that is aware of its internal state, has situational awareness of its environment, can assess its capabilities currently and project them into the future, understands its mission objectives, and can make decisions under uncertainty regarding its ability to achieve its mission objectives.

  17. 21 CFR 522.1451 - Moxidectin for suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... One contains 10 percent moxidectin microspheres, and the other contains a vehicle for constitution of the moxidectin microspheres. Each milliliter of constituted, sustained-release suspension contains...

  18. Rethinking Suspensions

    ERIC Educational Resources Information Center

    Stetson, Frank H.; Collins, Betty J.

    2010-01-01

    The overrepresentation of the Black and Hispanic subgroups in suspension data is a national problem and a troubling issue for schools and school systems across the United States. In Maryland, an analysis of student suspensions by school districts for the 2006-2007 school year revealed disproportionality issues. In 23 of the 24 jurisdictions,…

  19. Adaptation to Altitude as a Vehicle for Experiential Learning of Physiology by University Undergraduates

    ERIC Educational Resources Information Center

    Weigle, David S.; Buben, Amelia; Burke, Caitlin C.; Carroll, Nels D.; Cook, Brett M.; Davis, Benjamin S.; Dubowitz, Gerald; Fisher, Rian E.; Freeman, Timothy C.; Gibbons, Stephen M.; Hansen, Hale A.; Heys, Kimberly A.; Hopkins, Brittany; Jordan, Brittany L.; McElwain, Katherine L.; Powell, Frank L.; Reinhart, Katherine E.; Robbins, Charles D.; Summers, Cameron C.; Walker, Jennifer D.; Weber, Steven S.; Weinheimer, Caroline J.

    2007-01-01

    In this article, an experiential learning activity is described in which 19 university undergraduates made experimental observations on each other to explore physiological adaptations to high altitude. Following 2 wk of didactic sessions and baseline data collection at sea level, the group ascended to a research station at 12,500-ft elevation.…

  20. 49 CFR 393.207 - Suspension systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... braking system. The vehicle shall be level (not tilting to the left or right). Air leakage shall not be... 49 Transportation 5 2013-10-01 2013-10-01 false Suspension systems. 393.207 Section 393.207... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems §...

  1. 49 CFR 393.207 - Suspension systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... braking system. The vehicle shall be level (not tilting to the left or right). Air leakage shall not be... 49 Transportation 5 2014-10-01 2014-10-01 false Suspension systems. 393.207 Section 393.207... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems §...

  2. 49 CFR 393.207 - Suspension systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... braking system. The vehicle shall be level (not tilting to the left or right). Air leakage shall not be... 49 Transportation 5 2012-10-01 2012-10-01 false Suspension systems. 393.207 Section 393.207... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems §...

  3. Operator State Estimation for Adaptive Aiding in Uninhabited Combat Air Vehicles

    DTIC Science & Technology

    2005-09-01

    Michael, Eiselt, and Gert Griessbach. “Common Optimization of Adaptive Preprocessing Units and a Neural Network during the Learning Period...2000). Guger, Christop, Alois Schlögl, Christa Neuper, Dirk Walterspacher, Thomas Strein, and Gert Pfurtscheller. “Rapid Prototyping of an EEG...North_Holland, (1988). Haselsteiner, Ernst and Gert Pfurtscheller. “Using Time-Dependent Neural Networks for EEG Classification,” IEEE Transactions on

  4. Adaptive Behavior for Mobile Robots

    NASA Technical Reports Server (NTRS)

    Huntsberger, Terrance

    2009-01-01

    The term "System for Mobility and Access to Rough Terrain" (SMART) denotes a theoretical framework, a control architecture, and an algorithm that implements the framework and architecture, for enabling a land-mobile robot to adapt to changing conditions. SMART is intended to enable the robot to recognize adverse terrain conditions beyond its optimal operational envelope, and, in response, to intelligently reconfigure itself (e.g., adjust suspension heights or baseline distances between suspension points) or adapt its driving techniques (e.g., engage in a crabbing motion as a switchback technique for ascending steep terrain). Conceived for original application aboard Mars rovers and similar autonomous or semi-autonomous mobile robots used in exploration of remote planets, SMART could also be applied to autonomous terrestrial vehicles to be used for search, rescue, and/or exploration on rough terrain.

  5. Adaptive vision-based control of an unmanned aerial vehicle without linear velocity measurements.

    PubMed

    Jabbari Asl, Hamed; Yoon, Jungwon

    2016-11-01

    In this paper, an image-based visual servo controller is designed for an unmanned aerial vehicle. The main objective is to use flow of image features as the velocity cue to compensate for the low quality of linear velocity information obtained from accelerometers. Nonlinear observers are designed to estimate this flow. The proposed controller is bounded, which can help to keep the target points in the field of view of the camera. The main advantages over the previous full dynamic observer-based methods are that, the controller is robust with respect to unknown image depth, and also no yaw information is required. The complete stability analysis is presented and asymptotic convergence of the error signals is guaranteed. Simulation results show the effectiveness of the proposed approach.

  6. SSME to RS-25: Challenges of Adapting a Heritage Engine to a New Vehicle Architecture

    NASA Technical Reports Server (NTRS)

    Ballard, Richard O.

    2015-01-01

    A key constituent of the NASA Space Launch System (SLS) architecture is the RS-25 engine, also known as the Space Shuttle Main Engine (SSME). This engine was selected largely due to the maturity and extensive experience gained through 30-plus years of service. However, while the RS-25 is a highly mature system, simply unbolting it from the Space Shuttle and mounting it on the new SLS vehicle is not a "plug-and-play" operation. In addition to numerous technical integration and operational details, there were also hardware upgrades needed. While the magnitude of effort is less than that needed to develop a new clean-sheet engine system, this paper describes some of the expected and unexpected challenges encountered to date on the path to the first flight of SLS.

  7. Efficient integration of spectral features for vehicle tracking utilizing an adaptive sensor

    NASA Astrophysics Data System (ADS)

    Uzkent, Burak; Hoffman, Matthew J.; Vodacek, Anthony

    2015-03-01

    Object tracking in urban environments is an important and challenging problem that is traditionally tackled using visible and near infrared wavelengths. By inserting extended data such as spectral features of the objects one can improve the reliability of the identification process. However, huge increase in data created by hyperspectral imaging is usually prohibitive. To overcome the complexity problem, we propose a persistent air-to-ground target tracking system inspired by a state-of-the-art, adaptive, multi-modal sensor. The adaptive sensor is capable of providing panchromatic images as well as the spectra of desired pixels. This addresses the data challenge of hyperspectral tracking by only recording spectral data as needed. Spectral likelihoods are integrated into a data association algorithm in a Bayesian fashion to minimize the likelihood of misidentification. A framework for controlling spectral data collection is developed by incorporating motion segmentation information and prior information from a Gaussian Sum filter (GSF) movement predictions from a multi-model forecasting set. An intersection mask of the surveillance area is extracted from OpenStreetMap source and incorporated into the tracking algorithm to perform online refinement of multiple model set. The proposed system is tested using challenging and realistic scenarios generated in an adverse environment.

  8. AKSED: adaptive knowledge-based system for event detection using collaborative unmanned aerial vehicles

    NASA Astrophysics Data System (ADS)

    Wang, X. Sean; Lee, Byung Suk; Sadjadi, Firooz

    2006-05-01

    Advances in sensor technology and image processing have made it possible to equip unmanned aerial vehicles (UAVs) with economical, high-resolution, energy-efficient sensors. Despite the improvements, current UAVs lack autonomous and collaborative operation capabilities, due to limited bandwidth and limited on-board image processing abilities. The situation, however, is changing. In the next generation of UAVs, much image processing can be carried out onboard and communication bandwidth problem will improve. More importantly, with more processing power, collaborative operations among a team of autonomous UAVs can provide more intelligent event detection capabilities. In this paper, we present ideas for developing a system enabling target recognitions by collaborative operations of autonomous UAVs. UAVs are configured in three stages: manufacturing, mission planning, and deployment. Different sets of information are needed at different stages, and the resulting outcome is an optimized event detection code deployed onto a UAV. The envisioned system architecture and the contemplated methodology, together with problems to be addressed, are presented.

  9. SSME to RS-25: Challenges of Adapting a Heritage Engine to a New Vehicle Architecture

    NASA Technical Reports Server (NTRS)

    Ballard, Richard O.

    2015-01-01

    Following the cancellation of the Constellation program and retirement of the Space Shuttle, NASA initiated the Space Launch System (SLS) program to provide next-generation heavy lift cargo and crew access to space. A key constituent of the SLS architecture is the RS-25 engine, also known as the Space Shuttle Main Engine (SSME). The RS-25 was selected to serve as the main propulsion system for the SLS core stage in conjunction with the solid rocket boosters. This selection was largely based on the maturity and extensive experience gained through 135 missions, 3000+ ground tests, and over a million seconds total accumulated hot-fire time. In addition, there were also over a dozen functional flight assets remaining from the Space Shuttle program that could be leveraged to support the first four flights. However, while the RS-25 is a highly mature system, simply unbolting it from the Space Shuttle boat-tail and installing it on the new SLS vehicle is not a "plug-and-play" operation. In addition to numerous technical integration details involving changes to significant areas such as the environments, interface conditions, technical performance requirements, operational constraints and so on, there were other challenges to be overcome in the area of replacing the obsolete engine control system (ECS). While the magnitude of accomplishing this effort was less than that needed to develop and field a new clean-sheet engine system, the path to the first flight of SLS has not been without unexpected challenges.

  10. Comparison of Adaptive Spectral Estimation for Vehicle Speed Measurement with Radar Sensors.

    PubMed

    Shariff, Khairul Khaizi Mohd; Hoare, Edward; Daniel, Liam; Antoniou, Michail; Cherniakov, Mikhail

    2017-04-02

    Vehicle speed-over-ground (SoG) radar offers significant advantages over conventional speed measurement systems. Radar sensors enable contactless speed measurement, which is free from wheel slip. One of the key issues in SoG radar is the development of the Doppler shift estimation algorithm. In this paper, we compared two algorithms to estimate a mean Doppler frequency accurately. The first is the center-of-mass algorithm, which based on spectrum center-of-mass estimation with a bandwidth-limiting technique. The second is the cross-correlation algorithm, which is based on a cross-correlation technique by cross-correlating Doppler spectrum with a theoretical Gaussian curve. Analysis shows that both algorithms are computationally efficient and suitable for real-time SoG systems. Our extensive simulated and experimental results show both methods achieved low estimation error between 0.5% and 1.5% for flat road conditions. In terms of reliability, the cross-correlation method shows good performance under low Signal-to-Noise Ratio (SNR) while the center-of-mass method failed in this condition.

  11. 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.

  12. Inter-Module Ventilation Changes to the International Space Station Vehicle to Support Integration of the International Docking Adapter and Commercial Crew Vehicles

    NASA Technical Reports Server (NTRS)

    Link, Dwight E., Jr.; Balistreri, Steven F., Jr.

    2015-01-01

    The International Space Station (ISS) Environmental Control and Life Support System (ECLSS) is continuing to evolve in the post-Space Shuttle era. The ISS vehicle configuration that is in operation was designed for docking of a Space Shuttle vehicle, and designs currently under development for commercial crew vehicles require different interfaces. The ECLSS Temperature and Humidity Control Subsystem (THC) Inter-Module Ventilation (IMV) must be modified in order to support two docking interfaces at the forward end of ISS, to provide the required air exchange. Development of a new higher-speed IMV fan and extensive ducting modifications are underway to support the new Commercial Crew Vehicle interfaces. This paper will review the new ECLSS IMV development requirements, component design and hardware status, subsystem analysis and testing performed to date, and implementation plan to support Commercial Crew Vehicle docking.

  13. Acquiring Peak Samples from Phytoplankton Thin Layers and Intermediate Nepheloid Layers by an Autonomous Underwater Vehicle with Adaptive Triggering

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; McEwen, R.; Ryan, J. P.; Bellingham, J. G.; Harvey, J.; Vrijenhoek, R.

    2010-12-01

    Phytoplankton thin layers (PTLs) affect many fundamental aspects of coastal ocean ecology including primary productivity, development of harmful algal blooms (HABs) and the survival and growth of zooplankton and fish larvae. Intermediate nepheloid layers (INLs) that contain suspended particulate matter transported from the bottom boundary layer of continental shelves and slopes also affect biogeochemistry and ecology of ocean margins. To better understand the impacts of these types of layers, we have developed an adaptive sampling method for an autonomous underwater vehicle (AUV) to detect a layer (adjusting detection parameters in situ), acquire water samples from peaks in the layer, and acquire control samples outside the layer. We have used the method in a number of field experiments with the AUV Dorado, which is equipped with ten water samplers (called "gulpers"). In real time, the algorithm tracks background levels of fluorescence and optical backscatter and the peaks' baseline to ensure that detection is tuned to the ambient conditions. The algorithm cross-checks fluorescence and backscatter signals to differentiate PTLs from INLs. To capture peak water samples with minimal delay, the algorithm exploits the AUV's sawtooth (i.e., yo-yo) trajectory: the vehicle crosses the detected layer twice in one yo-yo cycle. At the first crossing, it detects the layer's peak and saves its signal height. Sampling is triggered at the second crossing when the signal reaches the saved peak height plus meeting additional timing and depth conditions. The algorithm is also capable of triggering gulpers to acquire control samples outside the layer for comparison with ambient water. The sequence of peak and control samples can be set based on need. In recent AUV Dorado missions, the algorithm triggered the gulpers to acquire peak and control samples from INLs and PTLs in Monterey Bay. Zooplankton analysis of some peak samples showed very high concentrations of mussel and barnacle

  14. An Adaptive Flow Solver for Air-Borne Vehicles Undergoing Time-Dependent Motions/Deformations

    NASA Technical Reports Server (NTRS)

    Singh, Jatinder; Taylor, Stephen

    1997-01-01

    This report describes a concurrent Euler flow solver for flows around complex 3-D bodies. The solver is based on a cell-centered finite volume methodology on 3-D unstructured tetrahedral grids. In this algorithm, spatial discretization for the inviscid convective term is accomplished using an upwind scheme. A localized reconstruction is done for flow variables which is second order accurate. Evolution in time is accomplished using an explicit three-stage Runge-Kutta method which has second order temporal accuracy. This is adapted for concurrent execution using another proven methodology based on concurrent graph abstraction. This solver operates on heterogeneous network architectures. These architectures may include a broad variety of UNIX workstations and PCs running Windows NT, symmetric multiprocessors and distributed-memory multi-computers. The unstructured grid is generated using commercial grid generation tools. The grid is automatically partitioned using a concurrent algorithm based on heat diffusion. This results in memory requirements that are inversely proportional to the number of processors. The solver uses automatic granularity control and resource management techniques both to balance load and communication requirements, and deal with differing memory constraints. These ideas are again based on heat diffusion. Results are subsequently combined for visualization and analysis using commercial CFD tools. Flow simulation results are demonstrated for a constant section wing at subsonic, transonic, and a supersonic case. These results are compared with experimental data and numerical results of other researchers. Performance results are under way for a variety of network topologies.

  15. Preceding Vehicle Detection and Tracking Adaptive to Illumination Variation in Night Traffic Scenes Based on Relevance Analysis

    PubMed Central

    Guo, Junbin; Wang, Jianqiang; Guo, Xiaosong; Yu, Chuanqiang; Sun, Xiaoyan

    2014-01-01

    Preceding vehicle detection and tracking at nighttime are challenging problems due to the disturbance of other extraneous illuminant sources coexisting with the vehicle lights. To improve the detection accuracy and robustness of vehicle detection, a novel method for vehicle detection and tracking at nighttime is proposed in this paper. The characteristics of taillights in the gray level are applied to determine the lower boundary of the threshold for taillights segmentation, and the optimal threshold for taillight segmentation is calculated using the OTSU algorithm between the lower boundary and the highest grayscale of the region of interest. The candidate taillight pairs are extracted based on the similarity between left and right taillights, and the non-vehicle taillight pairs are removed based on the relevance analysis of vehicle location between frames. To reduce the false negative rate of vehicle detection, a vehicle tracking method based on taillights estimation is applied. The taillight spot candidate is sought in the region predicted by Kalman filtering, and the disturbed taillight is estimated based on the symmetry and location of the other taillight of the same vehicle. Vehicle tracking is completed after estimating its location according to the two taillight spots. The results of experiments on a vehicle platform indicate that the proposed method could detect vehicles quickly, correctly and robustly in the actual traffic environments with illumination variation. PMID:25195855

  16. Adaptive Correlation Space Adjusted Open-Loop Tracking Approach for Vehicle Positioning with Global Navigation Satellite System in Urban Areas.

    PubMed

    Ruan, Hang; Li, Jian; Zhang, Lei; Long, Teng

    2015-08-28

    For vehicle positioning with Global Navigation Satellite System (GNSS) in urban areas, open-loop tracking shows better performance because of its high sensitivity and superior robustness against multipath. However, no previous study has focused on the effects of the code search grid size on the code phase measurement accuracy of open-loop tracking. Traditional open-loop tracking methods are performed by the batch correlators with fixed correlation space. The code search grid size, which is the correlation space, is a constant empirical value and the code phase measuring accuracy will be largely degraded due to the improper grid size, especially when the signal carrier-to-noise density ratio (C/N₀) varies. In this study, the Adaptive Correlation Space Adjusted Open-Loop Tracking Approach (ACSA-OLTA) is proposed to improve the code phase measurement dependent pseudo range accuracy. In ACSA-OLTA, the correlation space is adjusted according to the signal C/N₀. The novel Equivalent Weighted Pseudo Range Error (EWPRE) is raised to obtain the optimal code search grid sizes for different C/N₀. The code phase measuring errors of different measurement calculation methods are analyzed for the first time. The measurement calculation strategy of ACSA-OLTA is derived from the analysis to further improve the accuracy but reduce the correlator consumption. Performance simulation and real tests confirm that the pseudo range and positioning accuracy of ASCA-OLTA are better than the traditional open-loop tracking methods in the usual scenarios of urban area.

  17. A novel approach for state of charge estimation based on adaptive switching gain sliding mode observer in electric vehicles

    NASA Astrophysics Data System (ADS)

    Chen, Xiaopeng; Shen, Weixiang; Cao, Zhenwei; Kapoor, Ajay

    2014-01-01

    In this paper, a novel approach for battery state of charge (SOC) estimation in electric vehicles (EVs) based on an adaptive switching gain sliding mode observer (ASGSMO) has been presented. To design the ASGSMO for the SOC estimation, the state equations based on a battery equivalent circuit model (BECM) are derived to represent dynamic behaviours of a battery. Comparing with a conventional sliding mode observer, the ASGSMO has a capability of minimising chattering levels in the SOC estimation by using the self-adjusted switching gain while maintaining the characteristics of being able to compensate modelling errors caused by the parameter variations of the BECM. Lyapunov stability theory is adopted to prove the error convergence of the ASGSMO for the SOC estimation. The lithium-polymer battery (LiPB) is utilised to conduct experiments for determining the parameters of the BECM and verifying the effectiveness of the proposed ASGSMO in various discharge current profiles including EV driving conditions in both city and suburban.

  18. Power dissipation in automotive suspensions

    NASA Astrophysics Data System (ADS)

    Smith, Malcolm C.; Swift, Stuart J.

    2011-02-01

    For a standard quarter-car vehicle model and a road disturbance whose velocity profile is white noise, it is shown that the power dissipated in the suspension is proportional to the tyre vertical stiffness and the noise intensity, but is independent of all masses and suspension parameters. The dependence of this result on the modelling assumptions is explored. It is shown that the road disturbance model is ill-posed for the computation of power dissipation in the tyre and a modification is suggested. Computational results then indicate that the total power dissipation is still very insensitive to variations in vehicle and suspension parameters, but not tyre parameters, even though the suspension power dissipation and the tyre power dissipation vary individually. The extension of the result to half-car vehicle models is also considered. For both the pitch-plane and roll-plane models, it is found from numerical examples that the broad conclusion of large dependence of the total power dissipation on tyre parameters and small dependence on all other parameters remains. A brief discussion is included on the contribution to power loss due to rolling resistance.

  19. Self-powered suspension criterion and energy regeneration implementation scheme of motor-driven active suspension

    NASA Astrophysics Data System (ADS)

    Yan, Shuai; Sun, Weichao

    2017-09-01

    Active suspension systems have advantages on mitigating the effects of vehicle vibration caused by road roughness, which are one of the most important component parts in influencing the performances of vehicles. However, high amount of energy consumption restricts the application of active suspension systems. From the point of energy saving, this paper presents a self-powered criterion of the active suspension system to judge whether a motor-driven suspension can be self-powered or not, and then a motor parameter condition is developed as a reference to design a self-powered suspension. An energy regeneration implementation scheme is subsequently proposed to make the active suspension which has the potential to be self-powered achieve energy-saving target in the real application. In this implementation scheme, operating electric circuits are designed based on different working status of the actuator and power source and it is realizable to accumulate energy from road vibration and supply energy to the actuator by switching corresponding electric circuits. To apply the self-powered suspension criterion and energy regeneration implementation scheme, an active suspension system is designed with a constrained H∞ controller and calculation results indicate that it has the capability to be self-powered. Simulation results show that the performances of the self-powered active suspension are nearly the same as those of the active suspension with an external energy source and can achieve energy regeneration at the same time.

  20. Adaptation.

    PubMed

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  1. Design and analysis of an intelligent controller for active geometry suspension systems

    NASA Astrophysics Data System (ADS)

    Goodarzi, Avesta; Oloomi, Ehsan; Esmailzadeh, Ebrahim

    2011-02-01

    An active geometry suspension (AGS) system is a device to optimise suspension-related factors such as toe angle and roll centre height by controlling vehicle's suspension geometry. The suspension geometry could be changed through control of suspension mounting point's position. In this paper, analysis and control of an AGS system is addressed. First, the effects of suspension geometry change on roll centre height and toe angle are studied. Then, based on an analytical approach, the improvement of the vehicle's stability and handling due to the control of suspension geometry is investigated. In the next section, an eight-degree-of-freedom handling model of a sport utility vehicle equipped with an AGS system is introduced. Finally, a self-tuning proportional-integral controller has been designed, using the fuzzy control theory, to control the actuator that changes the geometry of the suspension system. The simulation results show that an AGS system can improve the handling and stability of the vehicle.

  2. Adaptive Correlation Space Adjusted Open-Loop Tracking Approach for Vehicle Positioning with Global Navigation Satellite System in Urban Areas

    PubMed Central

    Ruan, Hang; Li, Jian; Zhang, Lei; Long, Teng

    2015-01-01

    For vehicle positioning with Global Navigation Satellite System (GNSS) in urban areas, open-loop tracking shows better performance because of its high sensitivity and superior robustness against multipath. However, no previous study has focused on the effects of the code search grid size on the code phase measurement accuracy of open-loop tracking. Traditional open-loop tracking methods are performed by the batch correlators with fixed correlation space. The code search grid size, which is the correlation space, is a constant empirical value and the code phase measuring accuracy will be largely degraded due to the improper grid size, especially when the signal carrier-to-noise density ratio (C/N0) varies. In this study, the Adaptive Correlation Space Adjusted Open-Loop Tracking Approach (ACSA-OLTA) is proposed to improve the code phase measurement dependent pseudo range accuracy. In ACSA-OLTA, the correlation space is adjusted according to the signal C/N0. The novel Equivalent Weighted Pseudo Range Error (EWPRE) is raised to obtain the optimal code search grid sizes for different C/N0. The code phase measuring errors of different measurement calculation methods are analyzed for the first time. The measurement calculation strategy of ACSA-OLTA is derived from the analysis to further improve the accuracy but reduce the correlator consumption. Performance simulation and real tests confirm that the pseudo range and positioning accuracy of ASCA-OLTA are better than the traditional open-loop tracking methods in the usual scenarios of urban area. PMID:26343683

  3. Decoupling suspension controller based on magnetic flux feedback.

    PubMed

    Zhang, Wenqing; Li, Jie; Zhang, Kun; Cui, Peng

    2013-01-01

    The suspension module control system model has been established based on MIMO (multiple input and multiple output) state feedback linearization. We have completed decoupling between double suspension points, and the new decoupling method has been applied to CMS04 magnetic suspension vehicle in national mid-low-speed maglev experiment field of Tangshan city in China. Double suspension system model is very accurate for investigating stability property of maglev control system. When magnetic flux signal is taken back to the suspension control system, the suspension module's antijamming capacity for resisting suspension load variety has been proved. Also, the external force interference has been enhanced. As a result, the robustness and stability properties of double-electromagnet suspension control system have been enhanced.

  4. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  5. Design of the Electronic Brake Pressure Modulator Using a Direct Adaptive Fuzzy Controller in Commercial Vehicles for the Safety of Braking in Fail

    NASA Astrophysics Data System (ADS)

    Kim, Hunmo

    In the brake systems, it is important to reduce the rear brake pressure in order to secure the safety of the vehicle in braking. So, there was some research that reduced and controlled the rear brake pressure exactly like a L. S. P. V and a E. L. S. P. V. However, the previous research has some weaknesses: the L. S. P. V is a mechanical system and its brake efficiency is lower than the efficiency of E. L. S. P. V. But, the cost of E. L. S. P. V is very higher so its application to the vehicle is very difficult. Additionally, when a fail appears in the circuit which controls the valves, the fail results in some wrong operation of the valves. But, the previous researchers didn't take the effect of fail into account. Hence, the efficiency of them is low and the safety of the vehicle is not confirmed. So, in this paper we develop a new economical pressure modulator that exactly controls brake pressure and confirms the safety of the vehicle in any case using a direct adaptive fuzzy controller.

  6. Suspension and Debarment Regulations

    EPA Pesticide Factsheets

    Governmentwide Nonprocurement Suspension and Debarment Guidelines and EPA Implementation. Executive Order 12549 provides for a governmentwide system of nonprocurment (grants and cooperative agreements) debarment and suspension.

  7. Diesel Vehicle Maintenance Competencies.

    ERIC Educational Resources Information Center

    Braswell, Robert; And Others

    Designed to provide a model set of competencies, this manual presents tasks which were identified by employers, employees, and teachers as important in a postsecondary diesel vehicle maintenance curriculum. The tasks are divided into seven major component areas of instruction: chassis and suspension, diesel engines, diesel fuel, electrical,…

  8. Fluidic Technology Investigation - Suspension Damping Simulations

    DTIC Science & Technology

    1977-01-01

    IF (w (I LT’ CVM)~4$1 IF ( Wrf 1 0 i CmpY MX2)V?1112wW~ CALL ORPArIP:(Pcx) pP,i.,IERR) .......-or pi i v~,R4p CAlLA (QAI)Rr7,4,?,T.ERR) T F Z (I ~LT C V...Damper Damping Devices Suspension Systems Shock Absorbers Adaptive Suspension Systems Hydro -Fluidics 20. ABSTRACT (Continue on reverse side if necessary

  9. Electromagnetic suspension and levitation techniques

    NASA Astrophysics Data System (ADS)

    Jayawant, B. V.

    1988-04-01

    A comprehensive account is given of state-of-the-art and prospective electromagnetic and electromechanical suspension/levitation technologies, using both conventional and superconducting materials, with a view both to their performance improvements over differently grounded technologies and their economic feasibility. In addition to passenger-carrying vehicles, controlled DC electromagnet technologies have been applied to frictionless magnetic bearings, flow meters, conveyor systems, high-speed machine tool spindles, ultracentrifuges, turboalternators, corrosive-liquid pumps, gas compressors, high-vacuum pumps, and energy storage flywheels. Attention is given to the commercial prospects for devices based on superconducting magnets.

  10. The Stiffness Characteristics Study on an Interconnected Anti-Rolling Suspension System

    NASA Astrophysics Data System (ADS)

    Hou, Youshan; Song, Huixin; Ma, Ming; Xiao, Jie; Zhao, Ning

    The heavy-duty special vehicles easily roll during steering, anti-rolling technology becomes a critical technology to the heavy-duty vehicles. Aiming at the rolling problem of a full load heavy vehicle in the process of steering, an interconnected anti-rolling suspension system with adjustable damping was designed, the nonlinear stiffness mathematical model of interconnected anti-rolling suspension system was established. The stiffness characteristic was studied through digital simulation method, discussing the system parameter changes' affection on the stiffness performance of interconnected anti-rolling suspension system. The study results indicate that the interconnected anti-rolling suspension system betterly improves vehicles rolling resistance in contrast to the oil-gas mixed independent suspension, the study results provide theoretical basis for the anti-rolling's design of heavy-duty vehicles.

  11. EDITORIAL: Colloidal suspensions Colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Petukhov, Andrei; Kegel, Willem; van Duijneveldt, Jeroen

    2011-05-01

    Special issue in honour of Henk Lekkerkerker's 65th birthday Professor Henk N W Lekkerkerker is a world-leading authority in the field of experimental and theoretical soft condensed matter. On the occasion of his 65th birthday in the summer of 2011, this special issue celebrates his many contributions to science. Henk Lekkerkerker obtained his undergraduate degree in chemistry at the University of Utrecht (1968) and moved to Calgary where he received his PhD in 1971. He moved to Brussels as a NATO fellow at the Université Libre de Bruxelles and was appointed to an assistant professorship (1974), an associate professorship (1977) and a full professorship (1980) in physical chemistry at the Vrije Universiteit Brussel. In 1985 he returned to The Netherlands to take up a professorship at the Van 't Hoff Laboratory, where he has been ever since. He has received a series of awards during his career, including the Onsager Medal (1999) of the University of Trondheim, the Bakhuys Roozeboom Gold Medal (2003) of the Royal Dutch Academy of Arts and Sciences (KNAW), the ECIS-Rhodia European Colloid and Interface Prize (2003), and the Liquid Matter Prize of the European Physical Society (2008). He was elected a member of KNAW in 1996, was awarded an Academy Chair position in 2005, and has held several visiting lectureships. Henk's work focuses on phase transitions in soft condensed matter, and he has made seminal contributions to both the theoretical and experimental aspects of this field. Here we highlight three major themes running through his work, and a few selected publications. So-called depletion interactions may lead to phase separation in colloid-polymer mixtures, and Henk realised that the partitioning of polymer needs to be taken into account to describe the phase behaviour correctly [1]. Colloidal suspensions can be used as model fluids, with the time- and length-scales involved leading to novel opportunities, notably the direct observation of capillary waves at a

  12. Forestry Vehicle

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Power Pack II provides an economical means of moving a power source into remote roadless forest areas. It was developed by Prof. Miles and his associates, working in cooperation with the University of California's Department of Forestry. The team combined its own design of an all-terrain vehicle with a suspension system based on the NASA load equalization technology. Result is an intermediate-sized unit which carries a power source and the powered tools to perform a variety of forest management tasks which cannot be done economically with current equipment. Power Pack II can traverse very rough terrain and climb a 60 degree slope; any one of the wheels can move easily over an obstacle larger than itself. Work is being done on a more advanced Power Pack III.

  13. Scalable recombinant adeno-associated virus production using recombinant herpes simplex virus type 1 coinfection of suspension-adapted mammalian cells.

    PubMed

    Thomas, Darby L; Wang, Lijun; Niamke, Justine; Liu, Jilin; Kang, Wen; Scotti, Marina M; Ye, Guo-jie; Veres, Gabor; Knop, David R

    2009-08-01

    Recombinant adeno-associated virus (rAAV) production systems capable of meeting clinical or anticipated commercial-scale manufacturing needs have received relatively little scrutiny compared with the intense research activity afforded the in vivo and in vitro evaluation of rAAV for gene transfer. Previously we have reported a highly efficient recombinant herpes simplex virus type 1 (rHSV) complementation system for rAAV production in multiple adherent cell lines; however, production in a scalable format was not demonstrated. Here we report rAAV production by rHSV coinfection of baby hamster kidney (BHK) cells grown in suspension (sBHK cells), using two ICP27-deficient rHSV vectors, one harboring a transgene flanked by the AAV2 inverted terminal repeats and a second bearing the AAV rep2 and capX genes (where X is any rAAV serotype). The rHSV coinfection of sBHK cells produced similar rAAV1/AAT-specific yields (85,400 DNase-resistant particles [DRP]/cell) compared with coinfection of adherent HEK-293 cells (74,600 DRP/cell); however, sBHK cells permitted a 3-fold reduction in the rHSV-rep2/capX vector multiplicity of infection, grew faster than HEK-293 cells, retained specific yields (DRP/cell) at higher cell densities, and had a decreased virus production cycle. Furthermore, sBHK cells were able to produce AAV serotypes 1, 2, 5, and 8 at similar specific yields, using multiple therapeutic genes. rAAV1/AAT production in sBHK cells was scaled to 10-liter disposable bioreactors, using optimized spinner flask infection conditions, and resulted in average volumetric productivities as high as 2.4 x 10(14) DRP/liter.

  14. Urinary incontinence - retropubic suspension

    MedlinePlus

    ... Marchetti-Krantz (MMK) procedure; Laparoscopic retropubic colposuspension; Needle suspension; Burch colposuspension ... bladder. There are two ways to do retropubic suspension: open surgery or laparoscopic surgery. Either way, surgery ...

  15. Wear/comfort Pareto optimisation of bogie suspension

    NASA Astrophysics Data System (ADS)

    Milad Mousavi Bideleh, Seyed; Berbyuk, Viktor; Persson, Rickard

    2016-08-01

    Pareto optimisation of bogie suspension components is considered for a 50 degrees of freedom railway vehicle model to reduce wheel/rail contact wear and improve passenger ride comfort. Several operational scenarios including tracks with different curve radii ranging from very small radii up to straight tracks are considered for the analysis. In each case, the maximum admissible speed is applied to the vehicle. Design parameters are categorised into two levels and the wear/comfort Pareto optimisation is accordingly accomplished in a multistep manner to improve the computational efficiency. The genetic algorithm (GA) is employed to perform the multi-objective optimisation. Two suspension system configurations are considered, a symmetric and an asymmetric in which the primary or secondary suspension elements on the right- and left-hand sides of the vehicle are not the same. It is shown that the vehicle performance on curves can be significantly improved using the asymmetric suspension configuration. The Pareto-optimised values of the design parameters achieved here guarantee wear reduction and comfort improvement for railway vehicles and can also be utilised in developing the reference vehicle models for design of bogie active suspension systems.

  16. Flight Test of an L(sub 1) Adaptive Controller on the NASA AirSTAR Flight Test Vehicle

    NASA Technical Reports Server (NTRS)

    Gregory, Irene M.; Xargay, Enric; Cao, Chengyu; Hovakimyan, Naira

    2010-01-01

    This paper presents results of a flight test of the L-1 adaptive control architecture designed to directly compensate for significant uncertain cross-coupling in nonlinear systems. The flight test was conducted on the subscale turbine powered Generic Transport Model that is an integral part of the Airborne Subscale Transport Aircraft Research system at the NASA Langley Research Center. The results presented are for piloted tasks performed during the flight test.

  17. An adaptive dual-optimal path-planning technique for unmanned air vehicles with application to solar-regenerative high altitude long endurance flight

    NASA Astrophysics Data System (ADS)

    Whitfield, Clifford A.

    2009-12-01

    A multi-objective technique for Unmanned Air Vehicle (UAV) path and trajectory autonomy generation, through task allocation and sensor fusion has been developed. The Dual-Optimal Path-Planning (D-O.P-P.) Technique generates on-line adaptive flight paths for UAVs based on available flight windows and environmental influenced objectives. The environmental influenced optimal condition, known as the driver' determines the condition, within a downstream virtual window of possible vehicle destinations and orientation built from the UAV kinematics. The intermittent results are pursued by a dynamic optimization technique to determine the flight path. This sequential optimization technique is a multi-objective optimization procedure consisting of two goals, without requiring additional information to combine the conflicting objectives into a single-objective. An example case-study and additional applications are developed and the results are discussed; including the application to the field of Solar Regenerative (SR) High Altitude Long Endurance (HALE) UAV flight. Harnessing solar energy has recently been adapted for use on high altitude UAV platforms. An aircraft that uses solar panels and powered by the sun during the day and through the night by SR systems, in principle could sustain flight for weeks or months. The requirements and limitations of solar powered flight were determined. The SR-HALE UAV platform geometry and flight characteristics were selected from an existing aircraft that has demonstrated the capability for sustained flight through flight tests. The goals were to maintain continual Situational Awareness (SA) over a case-study selected Area of Interest (AOI) and existing UAV power and surveillance systems. This was done for still wind and constant wind conditions at altitude along with variations in latitude. The characteristics of solar flux and the dependence on the surface location and orientation were established along with fixed flight maneuvers for

  18. Propulsion and stabilization system for magnetically levitated vehicles

    DOEpatents

    Coffey, Howard T.

    1993-06-29

    A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.

  19. Design of a new adaptive fuzzy controller and its application to vibration control of a vehicle seat installed with an MR damper

    NASA Astrophysics Data System (ADS)

    Phu, Do Xuan; Shin, Do Kyun; Choi, Seung-Bok

    2015-08-01

    This paper presents a new adaptive fuzzy controller featuring a combination of two different control methodologies: H infinity control technique and sliding mode control. It is known that both controllers are powerful in terms of high performance and robust stability. However, both control methods require an accurate dynamic model to design a state variable based controller in order to maintain their advantages. Thus, in this work a fuzzy control method which does not require an accurate dynamic model is adopted and two control methodologies are integrated to maintain the advantages even in an uncertain environment of the dynamic system. After a brief explanation of the interval type 2 fuzzy logic, a new adaptive fuzzy controller associated with the H infinity control and sliding mode control is formulated on the basis of Lyapunov stability theory. Subsequently, the formulated controller is applied to vibration control of a vehicle seat equipped with magnetorheological fluid damper (MR damper in short). An experimental setup for realization of the proposed controller is established and vibration control performances such as acceleration at the driver’s seat are evaluated. In addition, in order to demonstrate the effectiveness of the proposed controller, a comparative work with two existing controllers is undertaken. It is shown through simulation and experiment that the proposed controller can provide much better vibration control performance than the two existing controllers.

  20. Parasite transmission through suspension feeding.

    PubMed

    Ben-Horin, Tal; Bidegain, Gorka; Huey, Lauren; Narvaez, Diego A; Bushek, David

    2015-10-01

    Suspension-feeding bivalve molluscs are confronted with a wide range of materials in the benthic marine environment. These materials include various sized plankton and the organic material derived from it, macroalgae, detritus and a diversity of microbial parasites that have adapted life stages to survive in the water column. For bivalve parasites to infect hosts though, they must first survive and remain infectious in the water column to make initial contact with hosts, and once in contact, enter and overcome elaborate pathways for particle sorting and selection. Even past these defenses, bivalve parasites are challenged with efficient systems of mechanical and chemical digestion and highly evolved systems of innate immunity. Here we review how bivalve parasites evade these hurdles to complete their life cycles and establish within bivalve hosts. We broadly cover significant viral, bacterial, and protozoan parasites of marine bivalve molluscs, and illustrate the emergent properties of these host-parasite systems where parasite transmission occurs through suspension feeding.

  1. Railway vehicle body structures

    SciTech Connect

    Not Available

    1985-01-01

    The strength and durability of railway vehicle structures is a major topic of engineering research and design. To reflect this importance the Railway Division of the Institution of Mechanical Engineers organised a conference to discuss all matters relating to railway vehicle design. This book presents the papers discussed in that conference. The contents include: Vehicle body design and the UIC's international contribution; LUL prototype 1986 stock - body structure; vehicle structure for the intermediate capacity transmit system vehicles; car body technology of advanced light rapid transit vehicles; concepts, techniques and experience in the idealization of car body structures for finite element analysis; Calcutta metropolitan railway; design for a lightweight diesel multiple unit body; the design of lightweight inter-city coal structures; the BREL international coach body shell structure; new concepts and design techniques versus material standards; structures of BR diesel electric freight locomotives; structural design philosophy for electric locomotives; suspension design for a locomotive with low structural frequencies; freight wagon structures; a finite element study of coal bodyside panels including the effects of joint flexibility; a fresh approach to the problem of car body design strength; energy absorption in automatic couplings and draw gear; passenger vehicle design loads and structural crashworthiness; design of the front part of railway vehicles (in case of frontal impact); the development of a theoretical technique for rail vehicle structural crashworthiness.

  2. New methods for state estimation and adaptive observation of environmental flow systems leveraging coordinated swarms of sensor vehicles

    NASA Astrophysics Data System (ADS)

    Bewley, Thomas

    2015-11-01

    Accurate long-term forecasts of the path and intensity of hurricanes are imperative to protect property and save lives. Accurate estimations and forecasts of the spread of large-scale contaminant plumes, such as those from Deepwater Horizon, Fukushima, and recent volcanic eruptions in Iceland, are essential for assessing environment impact, coordinating remediation efforts, and in certain cases moving folks out of harm's way. The challenges in estimating and forecasting such systems include: (a) environmental flow modeling, (b) high-performance real-time computing, (c) assimilating measured data into numerical simulations, and (d) acquiring in-situ data, beyond what can be measured from satellites, that is maximally relevant for reducing forecast uncertainty. This talk will focus on new techniques for addressing (c) and (d), namely, data assimilation and adaptive observation, in both hurricanes and large-scale environmental plumes. In particular, we will present a new technique for the energy-efficient coordination of swarms of sensor-laden balloons for persistent, in-situ, distributed, real-time measurement of developing hurricanes, leveraging buoyancy control only (coupled with the predictable and strongly stratified flowfield within the hurricane). Animations of these results are available at http://flowcontrol.ucsd.edu/3dhurricane.mp4 and http://flowcontrol.ucsd.edu/katrina.mp4. We also will survey our unique hybridization of the venerable Ensemble Kalman and Variational approaches to large-scale data assimilation in environmental flow systems, and how essentially the dual of this hybrid approach may be used to solve the adaptive observation problem in a uniquely effective and rigorous fashion.

  3. Nonlinear oscillatory processes in wheeled vehicles

    NASA Astrophysics Data System (ADS)

    Mikhlin, Yu. V.; Mitrokhin, S. G.

    2011-04-01

    The free damped vibrations of a wheeled vehicle with independent suspension are analyzed with allowance for the nonlinear characteristics of the suspension springs and shock absorbers. The vibrations of a wheeled vehicle with a suspension with smooth nonlinear characteristics are studied for a model with seven degrees of freedoms. The skeleton curves and nonlinear normal modes are obtained. For a model with two degrees of freedoms (quarter-car) that corresponds to axisymmetric vibrations, the nonlinear normal modes are found in the case of a shock absorber with nonsmooth nonlinear characteristic

  4. The Annular Suspension and Pointing System /ASPS/

    NASA Technical Reports Server (NTRS)

    Anderson, W. W.; Woolley, C. T.

    1978-01-01

    The Annular Suspension and Pointing System (ASPS) may be attached to a carrier vehicle for orientation, mechanical isolation, and fine pointing purposes applicable to space experiments. It has subassemblies for both coarse and vernier pointing. A fourteen-degree-of-freedom simulation of the ASPS mounted on a Space Shuttle has yielded initial performance data. The simulation describes: the magnetic actuators, payload sensors, coarse gimbal assemblies, control algorithms, rigid body dynamic models of the payload and Shuttle, and a control system firing model.

  5. Theoretical and FEM analysis of suspension and propulsion system with HTS hybrid electromagnets in an EMS Maglev model

    NASA Astrophysics Data System (ADS)

    Chung, Y. D.; Lee, C. Y.; Jang, J. Y.; Yoon, Y. S.; Ko, T. K.

    2011-11-01

    We have been constructed a proto-type electromagnetic suspension (EMS) based maglev vehicle system. The maglev concept utilizes magnetic forces for noncontact suspension, guidance and propulsion. The suspension system with high temperature superconducting (HTS) hybrid electromagnet (EM) is composed of HTS coils and normal coils, which consume little power to keep large suspension gap. The magnetic forces realize to guide the vehicle, propel the vehicle along the guide-way and assist in braking action. The proto-type EMS-based Maglev model is designed to keep the suspension gap of 20 mm. This paper presents the theoretical analysis of the maglev vehicle based on the EMS model to obtain the designing parameters for levitation and propulsion forces. The magnetic field distributions of the electromagnetic forces with hybrid EM and propulsion stator coils are analyzed based on three dimension (3D) finite element method (FEM) analysis. From the simulation results, appropriately design parameters of the suspension, guidance and propulsion were obtained.

  6. Independent wheel suspension system using constant velocity universal joints in combination with a single prop shaft joint and mounted differentials

    SciTech Connect

    Krude, W.

    1986-06-24

    An independent wheel suspension system is described for a vehicle having a chassis, vehicle support means for resiliently supporting the chassis for displacement with respect to a driving surface, a wheel assembly with a wheel rotatable about a wheel axis, and an engine adapted to provide driving torque about an engine output axis at an engine output, the independent wheel suspension system consists of: control arm means having a wheel end pivotably connected to the wheel assembly and a pair of frame ends pivotably connected to a respective pair of pivot bearings carried by the vehicle support means to define a swing axis therethrough; differential means comprising a differential housing, differential input means and differential output means within the differential housing establishing a respective differential input axis and a differential output axis substantially perpendicular thereto; transverse pivot means coupling the differential means and the vehicle support means for allowing the differential means to pivot relative to the vehicle support means about a transverse pivot axis substantially parallel to the differential output axis; and prop shaft means having a prop shaft axis and first and second prop shaft coupling means coupling, respectively, to the engine output and the differential input, the first prop shaft coupling means being a constant velocity universal joint, the second prop shaft coupling means being one of an axially splined joint or a fixed joint; whereby, as the first prop shaft coupling means undergoes articulation with respect to the prop shaft means as the chassis undergoes the displacement, the transverse pivot means allows the differential means to pivot relative to the vehicle support means about the transverse pivot axis to accommodate the articulation without articulation between the differential means and the prop shaft means.

  7. Collapsing granular suspensions.

    PubMed

    Kadau, D; Andrade, J S; Herrmann, H J

    2009-11-01

    A 2D contact dynamics model is proposed as a microscopic description of a collapsing suspension/soil to capture the essential physical processes underlying the dynamics of generation and collapse of the system. Our physical model is compared with real data obtained from in situ measurements performed with a natural collapsing/suspension soil. We show that the shear strength behavior of our collapsing suspension/soil model is very similar to the behavior of this collapsing suspension soil, for both the unperturbed and the perturbed phases of the material.

  8. Online state of charge and model parameters estimation of the LiFePO4 battery in electric vehicles using multiple adaptive forgetting factors recursive least-squares

    NASA Astrophysics Data System (ADS)

    Duong, Van-Huan; Bastawrous, Hany Ayad; Lim, KaiChin; See, Khay Wai; Zhang, Peng; Dou, Shi Xue

    2015-11-01

    This paper deals with the contradiction between simplicity and accuracy of the LiFePO4 battery states estimation in the electric vehicles (EVs) battery management system (BMS). State of charge (SOC) and state of health (SOH) are normally obtained from estimating the open circuit voltage (OCV) and the internal resistance of the equivalent electrical circuit model of the battery, respectively. The difficulties of the parameters estimation arise from their complicated variations and different dynamics which require sophisticated algorithms to simultaneously estimate multiple parameters. This, however, demands heavy computation resources. In this paper, we propose a novel technique which employs a simplified model and multiple adaptive forgetting factors recursive least-squares (MAFF-RLS) estimation to provide capability to accurately capture the real-time variations and the different dynamics of the parameters whilst the simplicity in computation is still retained. The validity of the proposed method is verified through two standard driving cycles, namely Urban Dynamometer Driving Schedule and the New European Driving Cycle. The proposed method yields experimental results that not only estimated the SOC with an absolute error of less than 2.8% but also characterized the battery model parameters accurately.

  9. Research on School Suspension

    ERIC Educational Resources Information Center

    Iselin, Anne-Marie

    2010-01-01

    Schools across the nation report increases in the use of punitive disciplinary methods (e.g., suspension). The need for these disciplinary practices to address serious student misconduct is undisputed. What research has questioned is why some students seem to be suspended more often than others, what effects suspension has on students, and whether…

  10. 32 CFR 935.51 - Motor vehicle violations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Motor vehicle violations. 935.51 Section 935.51... REGULATIONS WAKE ISLAND CODE Penalties § 935.51 Motor vehicle violations. Whoever is found guilty of a... than 30 days, or suspension or revocation of his motor vehicle operator's permit, or any combination...

  11. 32 CFR 935.51 - Motor vehicle violations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Motor vehicle violations. 935.51 Section 935.51... REGULATIONS WAKE ISLAND CODE Penalties § 935.51 Motor vehicle violations. Whoever is found guilty of a... than 30 days, or suspension or revocation of his motor vehicle operator's permit, or any combination...

  12. 32 CFR 935.51 - Motor vehicle violations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Motor vehicle violations. 935.51 Section 935.51... REGULATIONS WAKE ISLAND CODE Penalties § 935.51 Motor vehicle violations. Whoever is found guilty of a... than 30 days, or suspension or revocation of his motor vehicle operator's permit, or any combination...

  13. Hierarchical optimisation on scissor seat suspension characteristic and structure

    NASA Astrophysics Data System (ADS)

    Wang, Chunlei; Zhang, Xinjie; Guo, Konghui; Lv, Jiming; Yang, Yi

    2016-11-01

    Scissor seat suspension has been applied widely to attenuate the cab vibrations of commercial vehicles, while its design generally needs a trade-off between the seat acceleration and suspension travel, which creates a typical optimisation issue. A complexity for this issue is that the optimal dynamics parameters are not easy to approach solutions fast and unequivocally. Hence, the hierarchical optimisation on scissor seat suspension characteristic and structure is proposed, providing a top-down methodology with the globally optimal and fast convergent solutions to compromise these design contradictions. In details, a characteristic-oriented non-parametric dynamics model of the scissor seat suspension is formulated firstly via databases, describing its vertical dynamics accurately. Then, the ideal vertical stiffness-damping characteristic is cascaded via the characteristic-oriented model, and the structure parameters are optimised in accordance with a structure-oriented multi-body dynamics model of the scissor seat suspension. Eventually, the seat effective amplitude transmissibility factor, suspension travel and the CPU time for solving are evaluated. The results show the seat suspension performance and convergent speed of the globally optimal solutions are improved well. Hence, the proposed hierarchical optimisation methodology regarding characteristic and structure of the scissor seat suspension is promising for its virtual development.

  14. Apparatus for stopping a vehicle

    SciTech Connect

    Wattenburg, Willard H.; McCallen, David B.

    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.

  15. 32 CFR 636.3 - Suspension or revocation of driving privileges.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 4 2012-07-01 2011-07-01 true Suspension or revocation of driving privileges... INSTALLATIONS) Fort Stewart, Georgia § 636.3 Suspension or revocation of driving privileges. In addition to the... driving privileges applies to the operation of a motor vehicle on Fort Stewart/Hunter Army Airfield....

  16. 32 CFR 636.3 - Suspension or revocation of driving privileges.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 4 2013-07-01 2013-07-01 false Suspension or revocation of driving privileges... INSTALLATIONS) Fort Stewart, Georgia § 636.3 Suspension or revocation of driving privileges. In addition to the... driving privileges applies to the operation of a motor vehicle on Fort Stewart/Hunter Army Airfield....

  17. 32 CFR 636.3 - Suspension or revocation of driving privileges.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 4 2014-07-01 2013-07-01 true Suspension or revocation of driving privileges... INSTALLATIONS) Fort Stewart, Georgia § 636.3 Suspension or revocation of driving privileges. In addition to the... driving privileges applies to the operation of a motor vehicle on Fort Stewart/Hunter Army Airfield....

  18. 32 CFR 636.3 - Suspension or revocation of driving privileges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Suspension or revocation of driving privileges... INSTALLATIONS) Fort Stewart, Georgia § 636.3 Suspension or revocation of driving privileges. In addition to the... driving privileges applies to the operation of a motor vehicle on Fort Stewart/Hunter Army Airfield....

  19. 32 CFR 636.3 - Suspension or revocation of driving privileges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Suspension or revocation of driving privileges... INSTALLATIONS) Fort Stewart, Georgia § 636.3 Suspension or revocation of driving privileges. In addition to the... driving privileges applies to the operation of a motor vehicle on Fort Stewart/Hunter Army Airfield....

  20. 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.

  1. Design and modeling of new suspension system using direct drive servo-valve system actuated by piezostack actuator

    NASA Astrophysics Data System (ADS)

    Han, Chulhee; Kim, Wan Ho; Choi, Seung-Bok

    2016-04-01

    This paper proposes a new type of a direct-drive valve (DDV) suspension system for vehicle controlled by the piezostack actuator associated with displacement amplifier. In order to achieve this goal, a new type of controllable piezostack DDV damper is designed and its performance evaluation of damping force is undertaken. Next, a full vehicle suspension system consisting of sprung mass, spring, tire and the piezostack DDV damper is constructed. After deriving the governing equations of the motion for the proposed the piezostack DDV suspension system, the skyhook controller is implemented for the realization of the full vehicle. Analytical model of the whole suspension system is then derived and performance characteristics are analyzed through numerical simulation. Finally, vibration control responses of the vehicle suspension system such as vertical acceleration are evaluated under both bump and sine road conditions.

  2. Fragility in dense suspensions

    NASA Astrophysics Data System (ADS)

    Mari, Romain; Cates, Mike

    Dense suspensions can jam under shear when the volume fraction of solid material is large enough. In this work we investigate the mechanical properties of shear jammed suspensions with numerical simulations. In particular, we address the issue of the fragility of these systems, i.e., the type of mechanical response (elastic or plastic) they show when subject to a mechanical load differing from the one applied during their preparation history.

  3. Vehicle Rustproofing,

    DTIC Science & Technology

    1982-03-01

    Corrosion Areas - G.M.) 11. Vehicle Rustproofing Guide for Vehicle Maintenance Managers 12. Chart - Vehicle Buy Program FY 83-87 13. Vehicle ...on the Vehicle Buy Program. k. The impact of a total fleet rustproofing policy on industry. I. Potential problems in Quality Control and Warranty...FY83-87, the Air Force intends to buy $2.5 billion worth of vehicles (Atch 12); thus, a total fleet treatment program for that period could cost as

  4. Zero-Spring-Rate Mechanism/Air Suspension Cart

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Cooley, Victor M.

    1991-01-01

    Compact mechanism suspends articulating flexible structures with minimal constraints. Zero-spring-rate mechanism (ZSRM) air suspension cart used to suspend flexible, "mass-critical" articles like lightweight spacecraft undergoing such large motions as slewing, translation, and telescoping/retraction. Suspends flexible article undergoing large rigid-body motion concurrent with vibratory motion, with minimal interaction between suspended article and suspending hardware. Adaptive to active control, which reduces undesirable effects caused by friction, nonlinearity, and mass coupling. Practical for most suspension applications.

  5. Measurements and simulations of rail vehicle dynamics with respect to overturning risk

    NASA Astrophysics Data System (ADS)

    Thomas, Dirk; Berg, Mats; Stichel, Sebastian

    2010-01-01

    Rail vehicles are exposed to strong lateral influences through curves, track imperfections and crosswind leading to large deflections of the vehicle suspension systems and carbody displacements. In turn, this increases the risk of vehicle overturning. In the present work, multibody simulations are performed in order to study the motion in the secondary suspension. Suspension deflection measurements on a fast test train were carried out and used for validation of the simulations. The simulations show good agreement with the measurements and represent a good tool to predict the motion in the secondary suspension.

  6. Active control of an innovative seat suspension system with acceleration measurement based friction estimation

    NASA Astrophysics Data System (ADS)

    Ning, Donghong; Sun, Shuaishuai; Li, Hongyi; Du, Haiping; Li, Weihua

    2016-12-01

    In this paper, an innovative active seat suspension system for vehicles is presented. This seat suspension prototype is built with two low cost actuators each of which has one rotary motor and one gear reducer. A H∞ controller with friction compensation is designed for the seat suspension control system where the friction is estimated and compensated based on the measurement of seat acceleration. This principal aim of this research was to control the low frequency vibration transferred or amplified by the vehicle (chassis) suspension, and to maintain the passivity of the seat suspension at high frequency (isolation vibration) while taking into consideration the trade-off between the active seat suspension cost and its high frequency performance. Sinusoidal excitations of 1-4.5 Hz were applied to test the active seat suspension both when controlled and when uncontrolled and this is compared with a well-tuned passive heavy duty vehicle seat suspension. The results indicate the effectiveness of the proposed control algorithm within the tested frequencies. Further tests were conducted using the excitations generated from a quarter-car model under bump and random road profiles. The bump road tests indicate the controlled active seat suspension has good transient response performance. The Power Spectral Density (PSD) method and ISO 2631-1 standards were applied to analyse the seat suspension's acceleration under random road conditions. Although some low magnitude and high frequency noise will inevitably be introduced by the active system, the weighted-frequency Root Mean Square (RMS) acceleration shows that this may not have a large effect on ride comfort. In fact, the ride comfort is improved from being an 'a little uncomfortable' to a 'not uncomfortable' level when compared with the well-tuned passive seat suspension. This low cost active seat suspension design and the proposed controller with the easily measured feedback signals are very practical for real

  7. A simple and rapid method for purification of triamcinolone acetonide suspension for intravitreal injection.

    PubMed

    Hernaez-Ortega, Maria C; Soto-Pedre, Enrique

    2004-01-01

    Purification of triamcinolone acetonide suspension is important to avoid the potential toxic effects of the vehicle. The aim of this article is to describe a simple and rapid technique to remove the vehicle, instead of the long procedure described in the literature. Triamcinolone acetonide suspension was sedimented by density gradient centrifugation. In a few minutes, this new technique yielded a clear supernatant that was easily replaced by a nontoxic sterile solution. More prolonged procedures may not be convenient for unplanned treatments and may also contribute to a greater chance for contamination of the triamcinolone acetonide suspension.

  8. Vehicle body cover

    SciTech Connect

    Hirose, T.

    1987-01-13

    This patent describes a vehicle body covered with a vehicle body cover which comprises: a front cover part, a rear cover part, a pair of side cover parts, and a roof cover part: the front cover part having portions adapted to cover only a hood, an area around a windshield and tops of front fenders of a vehicle body. The portion covering the hood is separated from the portions covering the tops of the fenders by cuts in the front cover part, the front cover part having an un-cut portion corresponding to a position at which the hood is hinged to the car body. The front cover part has a cut-out at a position corresponding to the windshield of the vehicle body and the front cover part has at least one cut-out at a position corresponding to where a rear view mirror is attached to the vehicle body; and the rear cover part having portions adapted to cover an area around a rear window, a trunk lid and a rear end of the vehicle body, the portion covering the trunk lid separated from the rest of the rear cover part by cuts corresponding to three sides of the trunk lid and an un-cut portion corresponding to a position at which the trunk lid is hinged to the vehicle body. The rear cover part has a hole at position corresponding to a trunk lid lock, a cut-out portion at a position corresponding to the rear window of the vehicle body, a cut-out at a position corresponding to a license plate of the vehicle body and cut-outs at positions corresponding to rear taillights of the vehicle body.

  9. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXI, I--MAINTAINING THE AIR SYSTEM--CATERPILLAR DIESEL ENGINE, II--UNDERSTANDING REAR END SUSPENSION.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE AIR SYSTEM AND REAR AXLE SUSPENSION USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) AIR INDUCTION AND EXHAUST SYSTEM, (2) VALVE MECHANISM, (3) TROUBLESHOOTING THE AIR SYSTEM, (4) PURPOSE OF VEHICLE SUSPENSION, (5) TANDEM…

  10. Study on Dynamic Behaviour of Wishbone Suspension System

    NASA Astrophysics Data System (ADS)

    Kamal, M.; Rahman, M. M.

    2012-09-01

    This paper presents the characteristic model of the wishbone suspension system using the quarter car model approach. Suspension system in an automobile provides vehicle control and passenger comfort by providing isolation from road disturbances. This makes it essential that the detailed behavior of suspension should be known to optimize the performance. A kinetic study is performed using multi body system (MBS) analysis. The dirt road profile is considered as an applied loading. The spring constant, damping coefficient and sprung mass are studied on the performance of the suspension system. It can be observed that the spring constant is inversely related with time required to return to initial position and the amount of deformations. The damping ratio affects the suppression of spring oscillations, beyond a certain limit damping ration has the negligible effect. Sprung mass effected the equilibrium position of the suspension system with a small effect on its oscillation behavior. It is shown that the spring constant, damping ratio and sprung mass are significant parameters to design the suspension system. This study is essential for complete understanding of working of the suspension system and a future study with real geometries.

  11. Intelligent Vehicle Health Management

    NASA Technical Reports Server (NTRS)

    Paris, Deidre E.; Trevino, Luis; Watson, Michael D.

    2005-01-01

    As a part of the overall goal of developing Integrated Vehicle Health Management systems for aerospace vehicles, the NASA Faculty Fellowship Program (NFFP) at Marshall Space Flight Center has performed a pilot study on IVHM principals which integrates researched IVHM technologies in support of Integrated Intelligent Vehicle Management (IIVM). IVHM is the process of assessing, preserving, and restoring system functionality across flight and ground systems (NASA NGLT 2004). The framework presented in this paper integrates advanced computational techniques with sensor and communication technologies for spacecraft that can generate responses through detection, diagnosis, reasoning, and adapt to system faults in support of INM. These real-time responses allow the IIVM to modify the affected vehicle subsystem(s) prior to a catastrophic event. Furthermore, the objective of this pilot program is to develop and integrate technologies which can provide a continuous, intelligent, and adaptive health state of a vehicle and use this information to improve safety and reduce costs of operations. Recent investments in avionics, health management, and controls have been directed towards IIVM. As this concept has matured, it has become clear the INM requires the same sensors and processing capabilities as the real-time avionics functions to support diagnosis of subsystem problems. New sensors have been proposed, in addition, to augment the avionics sensors to support better system monitoring and diagnostics. As the designs have been considered, a synergy has been realized where the real-time avionics can utilize sensors proposed for diagnostics and prognostics to make better real-time decisions in response to detected failures. IIVM provides for a single system allowing modularity of functions and hardware across the vehicle. The framework that supports IIVM consists of 11 major on-board functions necessary to fully manage a space vehicle maintaining crew safety and mission

  12. Hybrid superconducting magnetic suspensions

    SciTech Connect

    Tixador, P.; Hiebel, P.; Brunet, Y.

    1996-07-01

    Superconductors, especially high T{sub c} ones, are the most attractive materials to design stable and fully passive magnetic suspensions which have to control five degrees of freedom. The hybrid superconducting magnetic suspensions present high performances and a simple cooling mode. They consist of a permanent magnet bearing, stabilized by a suitable magnet-superconductor structure. Several designs are given and compared in terms of forces and stiffnesses. The design of the magnet bearing plays an important part. The superconducting magnetic bearing participates less in levitation but must provide a high stabilizing stiffness. This is achieved by the magnet configuration, a good material in term of critical current density and field cooling. A hybrid superconducting suspension for a flywheel is presented. This system consists of a magnet thrust bearing stabilized by superconductors interacting with an alternating polarity magnet structure. First tests and results are reported. Superconducting materials are magnetically melt-textured YBaCuO.

  13. Identification of the technical state of suspension elements in railway systems

    NASA Astrophysics Data System (ADS)

    Martinod, Ronald Mauricio; René Betancur, German; Francisco Castañeda Heredia, Leonel

    2012-07-01

    The running safety and passenger comfort levels in a vehicle are tightly related to the technical state of the suspension elements. The technical state of the suspension depends of the service life time as its components become old and wear out. In this paper, a study on the dynamic behaviour of a railway vehicle is established in relation to the damping elements in one of its suspension stages. An experimental measurement model is developed, obtaining a set of useful signals for the identification of the dynamic parameters of the vehicle and developing a test through the application of the operational modal analysis technique, using least-squares complex exponential method as a basis to validate the numerical model of the multi-body system. Then, the study focuses on developing numerical simulations for the identification of the technical state of the dampers by the registration of dynamic variables under commercial service conditions and on estimating the state of the suspension elements.

  14. Modeling of concentrated suspensions

    NASA Astrophysics Data System (ADS)

    van den Brule, B. H. A. A.; Jongschaap, R. J. J.

    1991-03-01

    The constitutive equation of a concentrated suspension of spherical particles in a Newtonian medium is derived. To this end the method of local volume averaging is employed. To calculate the contribution of the particles to the stress tensor it is assumed that the stress generated in the interstitial holes between the particles is negligible compared to the stress generated in !he narrow gaps separating the particles. The use of the resulting expression is demonstrated with two examples on a cubical arrangement of particles: pure shear and simple shear. Furthermore, the validity of the lubrication approximation employed in this work is checked against the results derived by Nunan and Keller for periodic suspensions.

  15. Bacterial suspensions under flow

    NASA Astrophysics Data System (ADS)

    Clement, Eric; Lindner, Anke; Douarche, Carine; Auradou, Harold

    2016-11-01

    Fluids laden with motile bacteria enter in the category of active matter, a new field currently developing at the convergence of biology, hydrodynamics and statistical physics. Such suspensions were shown recently to exhibit singular macroscopic transport properties. In this paper we review some recent results, either theoretical or experimental, on the active fluid rheology. We focus principally on bacteria suspensions and the objective is to provide the basis for understanding the emergence of the singular constitutive relations characterizing the macroscopic transport properties of such an active fluid under flow.

  16. Magnetic Suspension Technology Workshop

    NASA Technical Reports Server (NTRS)

    Keckler, Claude R. (Editor); Groom, Nelson J. (Editor); Britcher, Colin P. (Editor)

    1993-01-01

    In order to identify the state of magnetic suspension technology in such areas as rotating systems, pointing of experiments or subsystems, payload isolation, and superconducting materials, a workshop on Magnetic Suspension Technology was held at the Langley Research Center in Hampton, Virginia, on 2-4 Feb. 1988. The workshop included five technical sessions in which a total of 24 papers were presented. The technical sessions covered the areas of pointing, isolation, and measurement, rotating systems, modeling and control, and superconductors. A list of attendees is provided.

  17. 40 CFR 86.612-97 - Suspension and revocation of certificates of conformity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... certificates of conformity. 86.612-97 Section 86.612-97 Protection of Environment ENVIRONMENTAL PROTECTION... Heavy-Duty Vehicles § 86.612-97 Suspension and revocation of certificates of conformity. (a) The certificate of conformity is immediately suspended with respect to any vehicle failing pursuant to §...

  18. 40 CFR 86.612-97 - Suspension and revocation of certificates of conformity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... certificates of conformity. 86.612-97 Section 86.612-97 Protection of Environment ENVIRONMENTAL PROTECTION... Heavy-Duty Vehicles § 86.612-97 Suspension and revocation of certificates of conformity. (a) The certificate of conformity is immediately suspended with respect to any vehicle failing pursuant to §...

  19. Combined control effects of brake and active suspension control on the global safety of a full-car nonlinear model

    NASA Astrophysics Data System (ADS)

    Tchamna, Rodrigue; Youn, Edward; Youn, Iljoong

    2014-05-01

    This paper focuses on the active safety of a full-vehicle nonlinear model during cornering. At first, a previously developed electronic stability controller (ESC) based on vehicle simplified model is applied to the full-car nonlinear model in order to control the vehicle yaw rate and side-slip angle. The ESC system was shown beneficial not only in tracking the vehicle path as close as possible, but it also helped in reducing the vehicle roll angle and influences ride comfort and road-holding capability; to tackle that issue and also to have better attitude motion, making use of optimal control theory the active suspension control gain is developed from a vehicle linear model and used to compute the active suspension control force of the vehicle nonlinear model. The active suspension control algorithm used in this paper includes the integral action of the suspension deflection in order to make zero the suspension deflection steady state and keep the vehicle chassis flat. Keeping the chassis flat reduces the vehicle load transfer and that is helpful for road holding and yaw rate tracking. The effects of the two controllers when they work together are analysed using various computer simulations with different steering wheel manoeuvres.

  20. Some cable suspension systems and their effects on the flexural frequencies of slender aerospace structures

    NASA Technical Reports Server (NTRS)

    Herr, R. W.

    1974-01-01

    The effects of several cable suspension configurations on the first free-free flexural frequency of uniform beams have been determined by experiment and analysis. The results of this study confirm that in general the larger the test vehicle the larger is the flexural frequency measurement error attributable to a given cable suspension configuration. For horizontally oriented beams representing modern aerospace vehicles of average size and flexibility, the restraining effects of all but the shortest support cables were minor. The restraining effects of support cables of moderate length attached near the base of vertically oriented vehicles were overshadowed by the effects of beam compression due to gravity.

  1. About the preliminary design of the suspension spring and shock absorber

    NASA Astrophysics Data System (ADS)

    Preda, I.

    2016-08-01

    The aim of this paper is to give some recommendation for the design of main-spring and shock absorber of motor vehicle suspensions. Starting from a 2DoF model, the suspension parameters are transferred on the real vehicle on the base of planar schemes for the linkage. For the coil spring, the equations that must be fulfilled simultaneously permit to calculate three geometrical parameters. The indications presented for the shock absorber permit to obtain the damping coefficients in the compression and rebound strokes and to calculate the power dissipated during the vehicle oscillatory movement.

  2. Keep solids in suspension

    SciTech Connect

    Gladki, H.Z.

    1997-10-01

    Mixing is an important operation in the CPI. It is not synonymous with agitation. Mixing is a random distribution into and through one another of two or more initially separate phases. Within that broad definition is the important specialty area of liquid-solid dispersion. This paper addresses the dispersion of solids in lower concentrations that don`t affect the rheological properties of the fluid. The just suspended condition represents the lowest grade of complete suspension, but this level of agitation is the most efficient for solids-liquid agitation. Higher mixing speeds waste energy. Undersized mixers need replacing. The top-entering mixer has a long history in the CPI and the environmental area. Many suspension studies were run with this type. These papers result in empirical correlations for just suspension conditions to scale up from laboratory measurement. Variables considered are the agitation speed, liquid and solids physical properties, solids concentration, system geometry and impeller type. Lately, submersible mixers are becoming more popular, but there are no published sizing methods. This article will explain how to define the critical hydraulic conditions in the tank to reach just solids suspension for a submersible agitator of the type described here as FJFA (Free Jet Flow Agitator).

  3. Flywheel Magnetic Suspension Developments

    NASA Technical Reports Server (NTRS)

    Palazzolo, Alan; Kenny, Andrew; Sifford, Curtiss; Thomas, Erwin; Bhuiyan, Mohammad; Provenza, Andrew; Kascak, Albert; Montague, Gerald; Lei, Shuliang; Kim, Yeonkyu; Sun, Guangyoung; Chon, ChonHee; Tucker, Randy; Preuss, Jason; Li, Ming; Minihan, Thomas

    2002-01-01

    The paper provides an overview of many areas of the flywheel magnetic suspension (MS) R&D being performed at the Texas A&M Vibration Control and Electromechanics Lab (TAMU-VCEL). This includes system response prediction, actuator optimization and redundancy, controller realizations and stages, sensor enhancements and backup bearing reliability.

  4. Crewbot Suspension Design

    NASA Technical Reports Server (NTRS)

    Wood, Nathan A.

    2005-01-01

    Planetary Surface Robot Work Crews (RWC) represent a new class of construction robots for future deployment in planetary exploration. Rovers currently being used for the RWC platform lack the load carrying capabilities required in regular work. Two new rovers, dubbed CrewBots, being designed in JPL's Planetary Robotics Lab specifically for RWC applications greatly increase the load carrying capabilities of the platform. A major component of the rover design was the design of the rocker type suspension, which increases rover mobility. The design of the suspension for the Crewbots departed from the design of recent rovers. While many previous rovers have used internal bevel gear differentials, the increased load requirements of the Crewbots calls for a more robust system. The solution presented is the use of an external modified three-bar, slider-linkage, rocker-style suspension that increases the moment arm of the differential. The final product is a suspension system capable of supporting the extreme loading cases the RWC platform presents, without consuming a large portion of the Crewbots' internal space.

  5. Alternatives to Student Suspension

    ERIC Educational Resources Information Center

    Robinett, David

    2012-01-01

    Seven years ago, James A. Garfield High School in East Los Angeles set a school record with 613 student suspensions, out of a total enrollment of 5,000 students. The school, made famous by the 1988 film "Stand and Deliver", was no stranger to the high rates of student discipline all too common within the Los Angeles Unified School…

  6. Viscosity of colloidal suspensions

    SciTech Connect

    Cohen, E.G.D.; Schepper, I.M. de

    1995-12-31

    Simple expressions are given for the effective Newtonian viscosity as a function of concentration as well as for the effective visco-elastic response as a function of concentration and imposed frequency, of monodisperse neutral colloidal suspensions over the entire fluid range. The basic physical mechanisms underlying these formulae are discussed. The agreement with existing experiments is very good.

  7. Clustering in Bubble Suspensions

    NASA Astrophysics Data System (ADS)

    Zenit, Roberto

    2000-11-01

    A monidisperse bubble suspension is studied experimentally for the limit in which the Weber number is small and the Reynolds number is large. For this regime the suspension can be modeled using potential flow theory to describe the dynamics of the interstitial fluid. Complete theoretical descriptions have been composed (Spelt and Sangani, 1998) to model the behavior of these suspensions. Bubble clustering is a natural instability that arises from the potential flow considerations, in which bubbles tend to align in horizontal rafts as they move upwards. The appearance of bubble clusters was recently corroborated experimentally by Zenit et al. (2000), who found that although clusters did appear, their strength was not as strong as the predictions. Experiments involving gravity driven shear flows are used to explain the nature of the clustering observed in these type of flows. Balances of the bubble phase pressure (in terms of a calculated diffusion coefficient) and the Maxwell pressure (from the potential flow description) are presented to predict the stability of the bubble suspension. The predictions are compared with experimental results.

  8. TRACKED VEHICLE Rev 75

    SciTech Connect

    Raby, Eric Y.

    2007-05-08

    Revision 75 of the Tracked Vehicle software is a soft real-time simulation of a differentially steered, tracked mobile robot, which, because of the track flippers, resembles the iRobot PackBot (http://www.irobot.com/). Open source libraries are used for the physics engine (http://www.ode.org/), the display and user interface (http://www.mathies.com/cpw/), and the program command line and configuration file parameters (http://www.boost.org/). The simulation can be controlled by a USB joystick or the keyboard. The configuration file contains demonstration model parameters of no particular vehicle. This simulation can be used as a starting point for those doing tracked vehicle simulations. This simulation software is essentially a research tool which can be modified and adapted for certain types of tracked vehicle research. An open source license allows an individual researchers to tailor the code to their specific research needs.

  9. Computer program for investigating effects of nonlinear suspension-system elastic properties on parachute inflation loads and motions

    NASA Technical Reports Server (NTRS)

    Poole, L. R.

    1972-01-01

    A computer program is presented by which the effects of nonlinear suspension-system elastic characteristics on parachute inflation loads and motions can be investigated. A mathematical elastic model of suspension-system geometry is coupled to the planar equations of motion of a general vehicle and canopy. Canopy geometry and aerodynamic drag characteristics and suspension-system elastic properties are tabular inputs. The equations of motion are numerically integrated by use of an equivalent fifth-order Runge-Kutta technique.

  10. Formulation and stability of diazepam suspension compounded from tablets.

    PubMed

    Strom, J G; Kalu, A U

    1986-06-01

    The stability of diazepam in an extemporaneous suspension compounded from tablets was studied. A diazepam 1 mg/mL suspension was prepared by levigating diazepam 10-mg tablets with ethanol and propylene glycol and incorporating them into a suspension vehicle containing magnesium aluminum silicate and carboxymethylcellulose sodium with flavoring and sweetening agents. Samples of the suspension were stored in amber glass bottles at 5, 22, and 40 degrees C. At various times during the 60-day study period, samples were inspected visually for signs of caking or color change and evaluated for ease of pouring and redispersion. Also at those times, the concentration of diazepam in each sample was determined by a stability-indicating, high-performance liquid chromatography procedure. The concentration of diazepam in each sample was at least 90% of the initial concentration throughout the 60-day storage period. All samples remained homogeneous and showed no signs of caking or settling. A diazepam suspension compounded from tablets was found to be pharmaceutically acceptable and easily pourable and redispersible. The suspension is stable for at least 60 days at room or refrigerated temperature.

  11. Space applications of diamagnetic suspensions

    NASA Technical Reports Server (NTRS)

    Pelrine, Ronald E.

    1992-01-01

    Conventional noncontact magnetic suspensions require power and sensor feedback to maintain stability of the levitated object. Magnetic suspensions using superconductors require neither power nor feedback for stability but must be maintained at low temperatures. This paper discusses a little known type of magnetic bearing that does not require power, sensor feedback, or cooling: diamagnetic suspension. While the bearing pressure for diamagnetic suspensions is typically limited to 1 g/sq cm, their simplicity, environmental tolerances, and wide range of material choices suggest that they may be useful for a number of space applications. This paper discusses the fundamentals of diamagnetic suspensions as well as their potential space applications.

  12. Optimization of damping in the passive automotive suspension system with using two quarter-car models

    NASA Astrophysics Data System (ADS)

    Lozia, Z.; Zdanowicz, P.

    2016-09-01

    The paper presents the optimization of damping in the passive suspension system of a motor vehicle moving rectilinearly with a constant speed on a road with rough surface of random irregularities, described according to the ISO classification. Two quarter-car 2DoF models, linear and non-linear, were used; in the latter, nonlinearities of spring characteristics of the suspension system and pneumatic tyres, sliding friction in the suspension system, and wheel lift-off were taken into account. The smoothing properties of vehicle tyres were represented in both models. The calculations were carried out for three roads of different quality, with simulating four vehicle speeds. Statistical measures of vertical vehicle body vibrations and of changes in the vertical tyre/road contact force were used as the criteria of system optimization and model comparison. The design suspension displacement limit was also taken into account. The optimum suspension damping coefficient was determined and the impact of undesirable sliding friction in the suspension system on the calculation results was estimated. The results obtained make it possible to evaluate the impact of the structure and complexity of the model used on the results of the optimization.

  13. Dense Suspension Splash

    NASA Astrophysics Data System (ADS)

    Zhang, Wendy; Dodge, Kevin M.; Peters, Ivo R.; Ellowitz, Jake; Klein Schaarsberg, Martin H.; Jaeger, Heinrich M.

    2014-03-01

    Upon impact onto a solid surface at several meters-per-second, a dense suspension plug splashes by ejecting liquid-coated particles. We study the mechanism for splash formation using experiments and a numerical model. In the model, the dense suspension is idealized as a collection of cohesionless, rigid grains with finite surface roughness. The grains also experience lubrication drag as they approach, collide inelastically and rebound away from each other. Simulations using this model reproduce the measured momentum distribution of ejected particles. They also provide direct evidence supporting the conclusion from earlier experiments that inelastic collisions, rather than viscous drag, dominate when the suspension contains macroscopic particles immersed in a low-viscosity solvent such as water. Finally, the simulations reveal two distinct routes for splash formation: a particle can be ejected by a single high momentum-change collision. More surprisingly, a succession of small momentum-change collisions can accumulate to eject a particle outwards. Supported by NSF through its MRSEC program (DMR-0820054) and fluid dynamics program (CBET-1336489).

  14. Stress in dilute suspensions

    NASA Technical Reports Server (NTRS)

    Passman, Stephen L.

    1989-01-01

    Generally, two types of theory are used to describe the field equations for suspensions. The so-called postulated equations are based on the kinetic theory of mixtures, which logically should give reasonable equations for solutions. The basis for the use of such theory for suspensions is tenuous, though it at least gives a logical path for mathematical arguments. It has the disadvantage that it leads to a system of equations which is underdetermined, in a sense that can be made precise. On the other hand, the so-called averaging theory starts with a determined system, but the very process of averaging renders the resulting system underdetermined. A third type of theory is proposed in which the kinetic theory of gases is used to motivate continuum equations for the suspended particles. This entails an interpretation of the stress in the particles that is different from the usual one. Classical theory is used to describe the motion of the suspending medium. The result is a determined system for a dilute suspension. Extension of the theory to more concentrated systems is discussed.

  15. The Tail Suspension Test

    PubMed Central

    Terrillion, Chantelle E.; Piantadosi, Sean C.; Bhat, Shambhu; Gould, Todd D.

    2012-01-01

    The tail-suspension test is a mouse behavioral test useful in the screening of potential antidepressant drugs, and assessing of other manipulations that are expected to affect depression related behaviors. Mice are suspended by their tails with tape, in such a position that it cannot escape or hold on to nearby surfaces. During this test, typically six minutes in duration, the resulting escape oriented behaviors are quantified. The tail-suspension test is a valuable tool in drug discovery for high-throughput screening of prospective antidepressant compounds. Here, we describe the details required for implementation of this test with additional emphasis on potential problems that may occur and how to avoid them. We also offer a solution to the tail climbing behavior, a common problem that renders this test useless in some mouse strains, such as the widely used C57BL/6. Specifically, we prevent tail climbing behaviors by passing mouse tails through a small plastic cylinder prior to suspension. Finally, we detail how to manually score the behaviors that are manifested in this test. PMID:22315011

  16. Air suspension characterisation and effectiveness of a variable area orifice

    NASA Astrophysics Data System (ADS)

    Alonso, A.; Giménez, J. G.; Nieto, J.; Vinolas, J.

    2010-12-01

    The air spring is one of the components that most affects vehicle comfort. This element usually makes up the main part of the secondary suspension, which introduces both stiffness and damping between the bogie and the car body. Therefore, a deep understanding of this element is necessary in order to study the comfort of a vehicle, the influence of different parameters and the ways to improve it. In this work, the effect of the air spring system on comfort is studied. To accomplish this, a typical pneumatic suspension composition is briefly studied as a first step. Then, the test bench developed to characterise air springs is described, presenting experimental results. Correlation of the results with some theoretical models is also addressed. Afterwards, the effect of the air spring system on comfort is analysed, and finally, improvements from introducing a variable area orifice in the pipe that joints the air spring and the surge reservoir are discussed.

  17. Novel oral suspensions: a review.

    PubMed

    Kathpalia, Harsha; Phadke, Chetan

    2014-01-01

    An oral pharmaceutical suspension has been one of the most favorable dosage forms for pediatric and geriatric patients or patients unable to tolerate solid dosage forms. The liquid form is preferred because of the ease of swallowing and flexibility in the administration of doses. This emerging area of suspensions as applied to the pharmaceutical field are discussed in the current article enlightening the vision of the readers towards pharmaceutical formulations including nanosuspensions, non-aqueous suspensions and modified release suspensions. The emphasis in the article focuses on the essential principles involved in the process of formation of different types of suspensions and their applications, since novel oral suspensions have potential to provide various strategy systems.

  18. Multiobjective optimisation of bogie suspension to boost speed on curves

    NASA Astrophysics Data System (ADS)

    Milad Mousavi-Bideleh, Seyed; Berbyuk, Viktor

    2016-01-01

    To improve safety and maximum admissible speed on different operational scenarios, multiobjective optimisation of bogie suspension components of a one-car railway vehicle model is considered. The vehicle model has 50 degrees of freedom and is developed in multibody dynamics software SIMPACK. Track shift force, running stability, and risk of derailment are selected as safety objective functions. The improved maximum admissible speeds of the vehicle on curves are determined based on the track plane accelerations up to 1.5 m/s2. To attenuate the number of design parameters for optimisation and improve the computational efficiency, a global sensitivity analysis is accomplished using the multiplicative dimensional reduction method (M-DRM). A multistep optimisation routine based on genetic algorithm (GA) and MATLAB/SIMPACK co-simulation is executed at three levels. The bogie conventional secondary and primary suspension components are chosen as the design parameters in the first two steps, respectively. In the last step semi-active suspension is in focus. The input electrical current to magnetorheological yaw dampers is optimised to guarantee an appropriate safety level. Semi-active controllers are also applied and the respective effects on bogie dynamics are explored. The safety Pareto optimised results are compared with those associated with in-service values. The global sensitivity analysis and multistep approach significantly reduced the number of design parameters and improved the computational efficiency of the optimisation. Furthermore, using the optimised values of design parameters give the possibility to run the vehicle up to 13% faster on curves while a satisfactory safety level is guaranteed. The results obtained can be used in Pareto optimisation and active bogie suspension design problems.

  19. Electric vehicles

    NASA Astrophysics Data System (ADS)

    1990-03-01

    Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. These concepts are discussed.

  20. Battery powererd electric motor vehicle

    SciTech Connect

    Muhlbacker, K.

    1984-02-28

    A battery powered vehicle is provided with a vehicle frame and an electric motor whose main shaft is connected to a differential gear by means of a gear train with a variable transmission ratio, the motor shaft and all gear shafts being parallel to the axle of the driving wheels. In order to achieve a compact design and to avoid power-consuming drive elements the electric motor and the variable transmission gear as well as a potential reducing gear mounted between the latter and the differential gear, are positioned on a subframe which is connected to the housing of the driving wheel axle on the one side whereas the other side carrying the electric motor is attached to the vehicle frame by means of a cardanic suspension.

  1. Effective Viscosity of Microswimmer Suspensions

    NASA Astrophysics Data System (ADS)

    Rafaï, Salima; Jibuti, Levan; Peyla, Philippe

    2010-03-01

    The measurement of a quantitative and macroscopic parameter to estimate the global motility of a large population of swimming biological cells is a challenge. Experiments on the rheology of active suspensions have been performed. Effective viscosity of sheared suspensions of live unicellular motile microalgae (Chlamydomonas Reinhardtii) is far greater than for suspensions containing the same volume fraction of dead cells. In addition, suspensions show shear thinning behavior. We relate these macroscopic measurements to the orientation of individual swimming cells under flow and discuss our results in the light of several existing models.

  2. Effective viscosity of microswimmer suspensions.

    PubMed

    Rafaï, Salima; Jibuti, Levan; Peyla, Philippe

    2010-03-05

    The measurement of a quantitative and macroscopic parameter to estimate the global motility of a large population of swimming biological cells is a challenge. Experiments on the rheology of active suspensions have been performed. Effective viscosity of sheared suspensions of live unicellular motile microalgae (Chlamydomonas Reinhardtii) is far greater than for suspensions containing the same volume fraction of dead cells. In addition, suspensions show shear thinning behavior. We relate these macroscopic measurements to the orientation of individual swimming cells under flow and discuss our results in the light of several existing models.

  3. 20 CFR 416.1320 - Suspensions; general.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Suspensions; general. 416.1320 Section 416..., BLIND, AND DISABLED Suspensions and Terminations § 416.1320 Suspensions; general. (a) When suspension is proper. Suspension of benefit payments is required when a recipient is alive but no longer meets...

  4. Aerodynamic Drag Reduction Apparatus For Wheeled Vehicles In Ground Effect

    DOEpatents

    Ortega, Jason M.; Salari, Kambiz

    2005-12-13

    An apparatus for reducing the aerodynamic drag of a wheeled vehicle in a flowstream, the vehicle having a vehicle body and a wheel assembly supporting the vehicle body. The apparatus includes a baffle assembly adapted to be positioned upstream of the wheel assembly for deflecting airflow away from the wheel assembly so as to reduce the incident pressure on the wheel assembly.

  5. A nonlinear kinematic and dynamic modeling of Macpherson suspension systems with a magneto-rheological damper

    NASA Astrophysics Data System (ADS)

    Dutta, Saikat; Choi, Seung-Bok

    2016-03-01

    It is well known that Macpherson strut suspension systems are widely used in light and medium weight vehicles. The performance of these suspension systems can be enriched by incorporating magneto-rheological (MR) dampers and an appropriate dynamic model is required in order to find out the ride comfort and other performances properly in the sense of practical environment conditions. Therefore, in this work the kinematic and dynamic modeling of Macpherson strut suspension system with MR damper is presented and its responses are evaluated. The governing equations are formulated using the kinematic properties of the suspension system and adopting Lagrange’s equation. In the formulation of the model, both the rotation of the wheel assembly and the lateral stiffness of the tire are considered to represent the nonlinear characteristic of Macpherson type suspension system. The formulated mathematical model is then compared with equivalent conventional quarter car suspension model and the different dynamic responses such as the displacement of the sprung mass are compared to emphasize the effectiveness of the proposed model. Additionally, in this work the important kinematic properties of suspension system such as camber angle, king-pin angle and track width alteration, which cannot be obtained from conventional quarter car suspension model, are evaluated in time and frequency domains. Finally, vibration control responses of the proposed suspension system are presented in time and frequency domains which are achieved from the semi-active sky-hook controller.

  6. The Enabler: A concept for a lunar work vehicle

    NASA Technical Reports Server (NTRS)

    Brazell, James W.; Campbell, Craig; Kaser, Ken; Austin, James A.; Beard, Clark; Ceniza, Glenn; Hamby, Thomas; Robinson, Anne; Wooters, Dana

    1992-01-01

    The Enabler is an earthbound prototype designed to model an actual lunar work vehicle and is able to perform many of the tasks that might be expected of a lunar work vehicle. The vehicle will be constructed entirely from parts made by students and from standard stock parts. The design utilizes only four distinct chassis pieces and sixteen moving parts. The Enabler has non-orthogonal articulating joints that give the vehicle a wide range of mobility and reduce the total number of parts. Composite wheels provide the primary suspension system for the vehicle.

  7. On-track tests of active vertical suspension on a passenger train

    NASA Astrophysics Data System (ADS)

    Qazizadeh, Alireza; Persson, Rickard; Stichel, Sebastian

    2015-06-01

    The classic way to design the suspension of a rail vehicle is to use passive elements such as dampers and springs; however, as sensors and actuators are getting more affordable and reliable, their potential benefit in the suspension system is increasingly studied. Active suspension can be used to keep ride comfort at an acceptable level or even improve it, while allowing tougher operation conditions or usage of lighter carbodies. Tougher conditions could be interpreted as higher speed or lower track quality, and lighter carbody means higher level of elastic vibrations. This paper is focused on the implementation and tests of active vertical suspension on the secondary suspension of a high-speed passenger electric multiple unit using hydraulic actuators and the skyhook method as the controller. Results from on-track tests indicate large ride comfort improvements.

  8. Comfort improvement of a nonlinear suspension using global optimization and in situ measurements

    NASA Astrophysics Data System (ADS)

    Deprez, K.; Moshou, D.; Ramon, H.

    2005-06-01

    The health problems encountered by operators of off-road vehicles demonstrate that a lot of effort still has to be put into the design of effective seat and cabin suspensions. Owing to the nonlinear nature of the suspensions and the use of in situ measurements for the optimization, classical local optimization techniques are prone to getting stuck in local minima. Therefore this paper develops a method for optimizing nonlinear suspension systems based on in situ measurements, using the global optimization technique DIRECT to avoid local minima. Evaluation of the comfort improvement of the suspension was carried out using the objective comfort parameters used in standards. As a test case, the optimization of a hydropneumatic element that can serve as part of a cabin suspension for off-road machinery was performed.

  9. Vehicle Characteristics

    DTIC Science & Technology

    2008-02-14

    Dimensions. Pertinent physical dimensions are determined using standard mensurative instrumentation such as steel tape measures, plumb bobs...vehicles use ITOP 2-2- 801(1)5. 4.2.3 Center of Gravity (CG). Determine the center of gravity of the test vehicle in accordance with TOP 2-2...8006. For tracked vehicles use ITOP 2-2-800(1)7. 4.2.4 Ground Pressure. Determine ground pressure in accordance with TOP 2-2-801. For tracked

  10. Launch vehicle

    NASA Astrophysics Data System (ADS)

    Rutledge, William S.

    1994-06-01

    Concentrated efforts by NASA and the DOD to begin development of a new large launch vehicle have been under way for over a decade. Options include the National Launch System, Advanced Launch System, a heavy lift vehicle, a Shuttle-derived vehicle, a Titan-derived vehicle, Single stage To Orbit, NASP and Spacelifter, to name a few. All initially promised low operations costs achieved at development costs in the $5 billion - $10 billion range. However, none has obtained approval for development, primarily because it became apparent that these cost goals could not realistically be met.

  11. Magnetic Suspension Technology Development

    NASA Technical Reports Server (NTRS)

    Britcher, Colin

    1998-01-01

    This Cooperative Agreement, intended to support focused research efforts in the area of magnetic suspension systems, was initiated between NASA Langley Research Center (LaRC) and Old Dominion University (ODU) starting January 1, 1997. The original proposal called for a three-year effort, but funding for the second year proved to be unavailable, leading to termination of the agreement following a 5-month no-cost extension. This report covers work completed during the entire 17-month period of the award. This research built on work that had taken place over recent years involving both NASA LARC and the Principal Investigator (PI). The research was of a rather fundamental nature, although specific applications were kept in mind at all times, such as wind tunnel Magnetic Suspension and Balance Systems (MSBS), space payload pointing and vibration isolation systems, magnetic bearings for unconventional applications, magnetically levitated ground transportation and electromagnetic launch systems. Fundamental work was undertaken in areas such as the development of optimized magnetic configurations, analysis and modelling of eddy current effects, control strategies for magnetically levitated wind tunnel models and system calibration procedures. Despite the termination of this Cooperative Agreement, several aspects of the research work are currently continuing with alternative forms of support.

  12. Dense suspension splash

    NASA Astrophysics Data System (ADS)

    Dodge, Kevin M.; Peters, Ivo R.; Ellowitz, Jake; Schaarsberg, Martin H. Klein; Jaeger, Heinrich M.; Zhang, Wendy W.

    2014-11-01

    Impact of a dense suspension drop onto a solid surface at speeds of several meters-per-second splashes by ejecting individual liquid-coated particles. Suppression or reduction of this splash is important for thermal spray coating and additive manufacturing. Accomplishing this aim requires distinguishing whether the splash is generated by individual scattering events or by collective motion reminiscent of liquid flow. Since particle inertia dominates over surface tension and viscous drag in a strong splash, we model suspension splash using a discrete-particle simulation in which the densely packed macroscopic particles experience inelastic collisions but zero friction or cohesion. Numerical results based on this highly simplified model are qualitatively consistent with observations. They also show that approximately 70% of the splash is generated by collective motion. Here an initially downward-moving particle is ejected into the splash because it experiences a succession of low-momentum-change collisions whose effects do not cancel but instead accumulate. The remainder of the splash is generated by scattering events in which a small number of high-momentum-change collisions cause a particle to be ejected upwards. Current Address: Physics of Fluids Group, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

  13. Roll and pitch independently tuned interconnected suspension: modelling and dynamic analysis

    NASA Astrophysics Data System (ADS)

    Xu, Guangzhong; Zhang, Nong; Roser, Holger M.

    2015-12-01

    In this paper, a roll and pitch independently tuned hydraulically interconnected passive suspension is presented. Due to decoupling of vibration modes and the improved lateral and longitudinal stability, the stiffness of individual suspension spring can be reduced for improving ride comfort and road grip. A generalised 14 degree-of-freedom nonlinear vehicle model with anti-roll bars is established to investigate the vehicle ride and handling dynamic responses. The nonlinear fluidic model of the hydraulically interconnected suspension is developed and integrated with the full vehicle model to investigate the anti-roll and anti-pitch characteristics. Time domain analysis of the vehicle model with the proposed suspension is conducted under different road excitations and steering/braking manoeuvres. The dynamic responses are compared with conventional suspensions to demonstrate the potential of enhanced ride and handling performance. The results illustrate the model-decoupling property of the hydraulically interconnected system. The anti-roll and anti-pitch performance could be tuned independently by the interconnected systems. With the improved anti-roll and anti-pitch characteristics, the bounce stiffness and ride damping can be optimised for better ride comfort and tyre grip.

  14. Frequency analysis of a semi-active suspension with magneto-rheological dampers

    NASA Astrophysics Data System (ADS)

    Andronic, Florin; Mihai, Ioan; Suciu, Cornel; Beniuga, Marius

    2015-02-01

    Suspension systems for motor vehicles are constantly evolving in order to ensure vehicle stability and traffic safety under all driving conditions. The present work aims to highlight the influence factors in the case of a quarter car model for semi-active suspensions. The functions that must be met by such suspension systems are first presented. Mathematical models for passive systems are first illustrated and then customized for the semi-active case. A simulation diagram was conceived for Matlab Simulink. The obtained simulation results allow conducting a frequency analysis of the passive and semi-active cases of the quarter car model. Various charts for Passive Suspension Transmissibility and for the Effect of Damping on Vertical Acceleration Response were obtained for both passive and semi-active situations. Analysis of obtained results allowed evaluating of the suspension systems behavior and their frequency dependence. Significant differences were found between the behaviors of passive and semi-active suspensions. It was found that semi-active suspensions ensure damping in accordance to the chosen control method, and are much more efficient than passive ones.

  15. 48 CFR 209.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Suspension. 209.407... OF DEFENSE ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 209.407 Suspension....

  16. 75 FR 27923 - Nonprocurement Debarment and Suspension

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-19

    ... 3150-AI76 Nonprocurement Debarment and Suspension AGENCY: Nuclear Regulatory Commission. ACTION: Final... nonprocurement debarment and suspension. These regulations cover grants, cooperative agreements and other...) guidance on nonprocurement debarment and suspension found in OMB's regulations. DATES: Effective June...

  17. Flow properties of concentrated suspensions

    NASA Technical Reports Server (NTRS)

    Hattori, K.; Izumi, K.

    1984-01-01

    The viscosity and flow behavior of a concentrated suspension, with special emphasis on fresh concrete containing a superplasticizer, is analyzed according to Newton's law of viscosity. The authors interpreted Newton's law in a new way, and explain non-Newton flow from Newton's law. The outline of this new theory is given. Viscosity of suspensions, and the effect of dispersants are analyzed.

  18. Diesel Technology: Steering and Suspension.

    ERIC Educational Resources Information Center

    Miller, Roger; Scarberry, Terry; Tesch, Carl; Kellum, Mary

    Competency-based teacher and student materials on steering and suspension are provided for a diesel technology curriculum. Eleven units of instruction cover the following topics: chassis, tires, and wheels; steering; and suspension. The materials are based on the curriculum-alignment concept of first stating the objectives, then developing…

  19. Vehicle systems: coupled and interactive dynamics analysis

    NASA Astrophysics Data System (ADS)

    Vantsevich, Vladimir V.

    2014-11-01

    This article formulates a new direction in vehicle dynamics, described as coupled and interactive vehicle system dynamics. Formalised procedures and analysis of case studies are presented. An analytical consideration, which explains the physics of coupled system dynamics and its consequences for dynamics of a vehicle, is given for several sets of systems including: (i) driveline and suspension of a 6×6 truck, (ii) a brake mechanism and a limited slip differential of a drive axle and (iii) a 4×4 vehicle steering system and driveline system. The article introduces a formal procedure to turn coupled system dynamics into interactive dynamics of systems. A new research direction in interactive dynamics of an active steering and a hybrid-electric power transmitting unit is presented and analysed to control power distribution between the drive axles of a 4×4 vehicle. A control strategy integrates energy efficiency and lateral dynamics by decoupling dynamics of the two systems thus forming their interactive dynamics.

  20. Utilisation of optimisation solutions to control active suspension for decreased braking distance

    NASA Astrophysics Data System (ADS)

    Edrén, Johannes; Jonasson, Mats; Jerrelind, Jenny; Stensson Trigell, Annika; Drugge, Lars

    2015-02-01

    This work deals with how to utilise active suspension on individual vehicle wheels in order to improve the vehicle performance during straight-line braking. Through numerical optimisation, solutions have been found as regards how active suspension should be controlled and coordinated with friction brakes to shorten the braking distance. The results show that, for the studied vehicle, the braking distance can be shortened by more than 1 m when braking from 100 km/h. The applicability of these results is studied by investigating the approach for different vehicle speeds and actuator stroke limitations. It is shown that substantial improvements in the braking distance can also be found for lower velocities, and that the actuator strokes are an important parameter. To investigate the potential of implementing these findings in a real vehicle, a validated detailed vehicle model equipped with active struts is analysed. Simplified control laws, appropriate for on-board implementation and based on knowledge of the optimised solution, are proposed and evaluated. The results show that substantial improvements of the braking ability, and thus safety, can be made using this simplified approach. Particle model simulations have been made to explain the underlying physical mechanisms and limitations of the approach. These results provide valuable guidance on how active suspension can be used to achieve significant improvements in vehicle performance with reasonable complexity and energy consumption.

  1. Suspension-Feeding Vertebrates.

    ERIC Educational Resources Information Center

    Sanderson, S. Laurie; Wassersug, Richard

    1990-01-01

    Described are animals that can filter their food out of the water. Various structures modified to strain plankton and small animals from water are detailed. The adaptive significance of these structures is discussed. (CW)

  2. Vehicle systems

    NASA Technical Reports Server (NTRS)

    Bales, Tom; Modlin, Tom; Suddreth, Jack; Wheeler, Tom; Tenney, Darrel R.; Bayless, Ernest O.; Lisagor, W. Barry; Bolstad, Donald A.; Croop, Harold; Dyer, J.

    1993-01-01

    Perspectives of the subpanel on expendable launch vehicle structures and cryotanks are: (1) new materials which provide the primary weight savings effect on vehicle mass/size; (2) today's investment; (3) typically 10-20 years to mature and fully characterize new materials.

  3. Descent vehicles

    NASA Technical Reports Server (NTRS)

    Popov, Y. I.

    1985-01-01

    The creation of descent vehicles marked a new stage in the development of cosmonautics, involving the beginning of manned space flight and substantial progress in space research on the distant bodies of the Solar System. This booklet describes these vehicles and their structures, systems, and purposes. It is intended for the general public interested in modern problems of space technology.

  4. Physics of colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Huang, Jiping

    Colloidal suspensions are complex fluids that consist of mesoscopic particles suspended in a solvent, e.g. water, oil, etc. In this thesis, the objective is to investigate the four aspects of colloidal suspensions: electrorotation, dielectrophoresis, dielectric dispersion spectrum, and nonlinear alternating current (AC) response. The traditional theories failed to fit the recent experimental data, and hence, for the purpose of a better fitting, we aim to develop new theories. In addition, our theories also predicted some new phenomena which are expected to be verified in experiments. Electrorotation has been increasingly employed as a sensitive tool for non-invasive studies of a broad variety of microparticles, ranging from living cells to spores and seeds, as well as synthetic materials. In order to analyze the abundant experimental data, we extend here the existing theory by taking into account crucial elements, such as inhomogeneities, multipolar interactions, nonspherical shapes as well as many-body (local-field) effects. Good agreement is shown between our theoretical results and the experimental data. Dielectrophoresis is typically used for micromanipulation and separation of biological cellular size particles, and it has recently been successfully applied to submicron size particles as well. Specific applications include diverse problems in medicine, colloidal science and nanotechnology. To analyze the recent experimental observations, we present a theory which includes the effects of both charging and multipolar interactions. Our theoretical results are favorably compared with the recent experimental observations. Recent experiments revealed that the dielectric dispersion spectrum of fission yeast cells in a suspension was mainly composed of two sub-dispersions. The low-frequency sub-dispersion depended on the cell length, while the high-frequency one was independent of it. However, the existing theory does not fit the experimental data. Hence, we here put

  5. Suspension Needn't Arrest Learning.

    ERIC Educational Resources Information Center

    Seegrist, Ruth

    1985-01-01

    An inschool suspension program at a Pennsylvania school district is described. Students spend suspension time completing classroom assignments under strict teacher supervision in detention halls. (TE)

  6. State observer-based sliding mode control for semi-active hydro-pneumatic suspension

    NASA Astrophysics Data System (ADS)

    Ren, Hongbin; Chen, Sizhong; Zhao, Yuzhuang; Liu, Gang; Yang, Lin

    2016-02-01

    This paper proposes an improved virtual reference model for semi-active suspension to coordinate the vehicle ride comfort and handling stability. The reference model combines the virtues of sky-hook with ground-hook control logic, and the hybrid coefficient is tuned according to the longitudinal and lateral acceleration so as to improve the vehicle stability especially in high-speed condition. Suspension state observer based on unscented Kalman filter is designed. A sliding mode controller (SMC) is developed to track the states of the reference model. The stability of the SMC strategy is proven by means of Lyapunov function taking into account the nonlinear damper characteristics and sprung mass variation of the vehicle. Finally, the performance of the controller is demonstrated under three typical working conditions: the random road excitation, speed bump road and sharp acceleration and braking. The simulation results indicated that, compared with the traditional passive suspension, the proposed control algorithm can offer a better coordination between vehicle ride comfort and handling stability. This approach provides a viable alternative to costlier active suspension control systems for commercial vehicles.

  7. Dielectric Constant of Suspensions

    NASA Astrophysics Data System (ADS)

    Mendelson, Kenneth S.; Ackmann, James J.

    1997-03-01

    We have used a finite element method to calculate the dielectric constant of a cubic array of spheres. Extensive calculations support preliminary conclusions reported previously (K. Mendelson and J. Ackmann, Bull. Am. Phys. Soc. 41), 657 (1996).. At frequencies below 100 kHz the real part of the dielectric constant (ɛ') shows oscillations as a function of the volume fraction of suspension. These oscillations disappear at low conductivities of the suspending fluid. Measurements of the dielectric constant (J. Ackmann, et al., Ann. Biomed. Eng. 24), 58 (1996). (H. Fricke and H. Curtis, J. Phys. Chem. 41), 729 (1937). are not sufficiently sensitive to show oscillations but appear to be consistent with the theoretical results.

  8. Electrorheology of nanofiber suspensions

    PubMed Central

    2011-01-01

    Electrorheological (ER) fluid, which can be transformed rapidly from a fluid-like state to a solid-like state under an external electric field, is considered to be one of the most important smart fluids. However, conventional ER fluids based on microparticles are subjected to challenges in practical applications due to the lack of versatile performances. Recent researches of using nanoparticles as the dispersal phase have led to new interest in the development of non-conventional ER fluids with improved performances. In this review, we especially focus on the recent researches on electrorheology of various nanofiber-based suspensions, including inorganic, organic, and inorganic/organic composite nanofibers. Our goal is to highlight the advantages of using anisotropic nanostructured materials as dispersal phases to improve ER performances. PMID:21711790

  9. Dynamic Performance of Subway Vehicle with Linear Induction Motor System

    NASA Astrophysics Data System (ADS)

    Wu, Pingbo; Luo, Ren; Hu, Yan; Zeng, Jing

    The light rail vehicle with Linear Induction Motor (LIM) bogie, which is a new type of urban rail traffic tool, has the advantages of low costs, wide applicability, low noise, simple maintenance and better dynamic behavior. This kind of vehicle, supported and guided by the wheel and rail, is not driven by the wheel/rail adhesion force, but driven by the electromagnetic force between LIM and reaction plate. In this paper, three different types of suspensions and their characteristic are discussed with considering the interactions both between wheel and rail and between LIM and reaction plate. A nonlinear mathematical model of the vehicle with LIM bogie is set up by using the software SIMPACK, and the electromechanical model is also set up on Simulink roof. Then the running behavior of the LIM vehicle is simulated, and the influence of suspension on the vehicle dynamic performance is investigated.

  10. Technical analysis of alternative fueled vehicles

    NASA Astrophysics Data System (ADS)

    1993-03-01

    The current status of alternative fueled vehicles, such as methanol fueled, compressed natural gas (CNG) fueled, and electric vehicles, that have feasibility to take the place of oil fueled ones is analyzed from the viewpoints of environmental pollution control, energy resources conservation, and economic performances. As for environmental pollution control, these three vehicles are compared by such items as nitrogen oxides, photochemical reactivity, adaptability to future regulations, earth warming substances, and toxicity. As for practical applicability, the following items are compared: power density (torque, power, acceleration performance), energy density, range, energy consumption, vehicle initial costs, energy costs, freight transportation energy costs (yen/ton/km), and energy supply suitability. Conclusions include: methanol vehicles have the problem of fueling stations to be arranged; since CNG vehicles are considered to be loaded with CNG fuel tanks on the top of vehicles, safety must be ensured; electric vehicles still have many problems in spite of their many advantages.

  11. Fault detection in electromagnetic suspension systems with state estimation methods

    SciTech Connect

    Sinha, P.K.; Zhou, F.B.; Kutiyal, R.S. . Dept. of Engineering)

    1993-11-01

    High-speed maglev vehicles need a high level of safety that depends on the whole vehicle system's reliability. There are many ways of attaining high reliability for the system. Conventional method uses redundant hardware with majority vote logic circuits. Hardware redundancy costs more, weigh more and occupy more space than that of analytically redundant methods. Analytically redundant systems use parameter identification and state estimation methods based on the system models to detect and isolate the fault of instruments (sensors), actuator and components. In this paper the authors use the Luenberger observer to estimate three state variables of the electromagnetic suspension system: position (airgap), vehicle velocity, and vertical acceleration. These estimates are compared with the corresponding sensor outputs for fault detection. In this paper, they consider FDI of the accelerometer, the sensor which provides the ride quality.

  12. Dynamic stability of repulsive-force maglev suspension systems

    SciTech Connect

    Cai, Y.; Rote, D.M.; Mulcahy, T.M.; Wang, Z.

    1996-11-01

    This report summarizes the research performed on maglev vehicle dynamic stability at Argonne National Laboratory during the past few years. It also documents both measured and calculated magnetic-force data. Because dynamic instability is not acceptable for any commercial maglev system, it is important to consider this phenomenon in the development of all maglev systems. This report presents dynamic stability experiments on maglev systems and compares the results with predictions calculated by a nonlinear-dynamics computer code. Instabilities of an electrodynamic-suspension system type vehicle model were obtained by experimental observation and computer simulation of a five-degree-of-freedom maglev vehicle moving on a guideway that consists of a pair of L-shaped aluminum conductors attached to a rotating wheel. The experimental and theoretical analyses developed in this study identify basic stability characteristics and future research needs of maglev systems.

  13. Space vehicle

    NASA Technical Reports Server (NTRS)

    Vonpragenau, G. L. (Inventor)

    1975-01-01

    A space vehicle having an improved ascent configuration for use in traveling in space is presented. Components of the vehicle are: (1) a winged orbiter having an elongater fuselage and rearwardly directed main engines fixed to the fuselage; (2) an elongated tank assembly of an improved configuration disposed forwardly of the fuselage and connected with the main engines of the vehicle for supplying liquid propellants; and (3) a booster stage comprising a pair of integrated solid rocket boosters connected with the orbiter immediately beneath the fuselage and extended in substantial parallelism.

  14. Passive detection of vehicle loading

    NASA Astrophysics Data System (ADS)

    McKay, Troy R.; Salvaggio, Carl; Faulring, Jason W.; Salvaggio, Philip S.; McKeown, Donald M.; Garrett, Alfred J.; Coleman, David H.; Koffman, Larry D.

    2012-01-01

    The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

  15. PASSIVE DETECTION OF VEHICLE LOADING

    SciTech Connect

    Garrett, A.

    2012-01-03

    The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

  16. Unifying suspension and granular rheology.

    PubMed

    Boyer, François; Guazzelli, Élisabeth; Pouliquen, Olivier

    2011-10-28

    Using an original pressure-imposed shear cell, we study the rheology of dense suspensions. We show that they exhibit a viscoplastic behavior similarly to granular media successfully described by a frictional rheology and fully characterized by the evolution of the friction coefficient μ and the volume fraction ϕ with a dimensionless viscous number I(v). Dense suspension and granular media are thus unified under a common framework. These results are shown to be compatible with classical empirical models of suspension rheology and provide a clear determination of constitutive laws close to the jamming transition.

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

    DOEpatents

    Bockelmann, Thomas R.; Hope, Mark E.; Zou, Zhanjiang; Kang, Xiaosong

    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.

  18. Development of an air pneumatic suspension system for transtibial prostheses.

    PubMed

    Pirouzi, Gholamhossein; Abu Osman, Noor Azuan; Oshkour, Azim Ataollahi; Ali, Sadeeq; Gholizadeh, Hossein; Abas, Wan A B Wan

    2014-09-09

    The suspension system and socket fitting of artificial limbs have major roles and vital effects on the comfort, mobility, and satisfaction of amputees. This paper introduces a new pneumatic suspension system that overcomes the drawbacks of current suspension systems in donning and doffing, change in volume during daily activities, and pressure distribution in the socket-stump interface. An air pneumatic suspension system (APSS) for total-contact sockets was designed and developed. Pistoning and pressure distribution in the socket-stump interface were tested for the new APSS. More than 95% of the area between each prosthetic socket and liner was measured using a Tekscan F-Scan pressure measurement which has developed matrix-based pressure sensing systems. The variance in pressure around the stump was 8.76 kPa. APSS exhibits less pressure concentration around the stump, improved pressure distribution, easy donning and doffing, adjustability to remain fitted to the socket during daily activities, and more adaptability to the changes in stump volume. The volume changes were adjusted by utility of air pressure sensor. The vertical displacement point and reliability of suspension were assessed using a photographic method. The optimum pressure in every level of loading weight was 55 kPa, and the maximum displacement was 6 mm when 90 N of weight was loaded.

  19. A suspension-feeding anomalocarid from the Early Cambrian.

    PubMed

    Vinther, Jakob; Stein, Martin; Longrich, Nicholas R; Harper, David A T

    2014-03-27

    Large, actively swimming suspension feeders evolved several times in Earth's history, arising independently from groups as diverse as sharks, rays and stem teleost fishes, and in mysticete whales. However, animals occupying this niche have not been identified from the early Palaeozoic era. Anomalocarids, a group of stem arthropods that were the largest nektonic animals of the Cambrian and Ordovician periods, are generally thought to have been apex predators. Here we describe new material from Tamisiocaris borealis, an anomalocarid from the Early Cambrian (Series 2) Sirius Passet Fauna of North Greenland, and propose that its frontal appendage is specialized for suspension feeding. The appendage bears long, slender and equally spaced ventral spines furnished with dense rows of long and fine auxiliary spines. This suggests that T. borealis was a microphagous suspension feeder, using its appendages for sweep-net capture of food items down to 0.5 mm, within the size range of mesozooplankton such as copepods. Our observations demonstrate that large, nektonic suspension feeders first evolved during the Cambrian explosion, as part of an adaptive radiation of anomalocarids. The presence of nektonic suspension feeders in the Early Cambrian, together with evidence for a diverse pelagic community containing phytoplankton and mesozooplankton, indicate the existence of a complex pelagic ecosystem supported by high primary productivity and nutrient flux. Cambrian pelagic ecosystems seem to have been more modern than previously believed.

  20. Development of an Air Pneumatic Suspension System for Transtibial Prostheses

    PubMed Central

    Pirouzi, Gholamhossein; Osman, Noor Azuan Abu; Oshkour, Azim Ataollahi; Ali, Sadeeq; Gholizadeh, Hossein; Wan Abas, Wan A. B.

    2014-01-01

    The suspension system and socket fitting of artificial limbs have major roles and vital effects on the comfort, mobility, and satisfaction of amputees. This paper introduces a new pneumatic suspension system that overcomes the drawbacks of current suspension systems in donning and doffing, change in volume during daily activities, and pressure distribution in the socket-stump interface. An air pneumatic suspension system (APSS) for total-contact sockets was designed and developed. Pistoning and pressure distribution in the socket-stump interface were tested for the new APSS. More than 95% of the area between each prosthetic socket and liner was measured using a Tekscan F-Scan pressure measurement which has developed matrix-based pressure sensing systems. The variance in pressure around the stump was 8.76 kPa. APSS exhibits less pressure concentration around the stump, improved pressure distribution, easy donning and doffing, adjustability to remain fitted to the socket during daily activities, and more adaptability to the changes in stump volume. The volume changes were adjusted by utility of air pressure sensor. The vertical displacement point and reliability of suspension were assessed using a photographic method. The optimum pressure in every level of loading weight was 55 kPa, and the maximum displacement was 6 mm when 90 N of weight was loaded. PMID:25207872

  1. Robotic vehicle

    DOEpatents

    Box, W.D.

    1998-08-11

    A robotic vehicle is described for travel through a conduit. The robotic vehicle includes forward and rear housings each having a hub portion, and each being provided with surface engaging mechanisms for selectively engaging the walls of the conduit such that the housings can be selectively held in stationary positions within the conduit. The surface engaging mechanisms of each housing includes a plurality of extendible appendages, each of which is radially extendible relative to the operatively associated hub portion between a retracted position and a radially extended position. The robotic vehicle also includes at least three selectively extendible members extending between the forward and rear housings, for selectively changing the distance between the forward and rear housings to effect movement of the robotic vehicle. 20 figs.

  2. Robotic vehicle

    DOEpatents

    Box, W.D.

    1997-02-11

    A robotic vehicle is described for travel through a conduit. The robotic vehicle includes forward and rear housings each having a hub portion, and each being provided with surface engaging mechanisms for selectively engaging the walls of the conduit such that the housings can be selectively held in stationary positions within the conduit. The surface engaging mechanisms of each housing includes a plurality of extendable appendages, each of which is radially extendable relative to the operatively associated hub portion between a retracted position and a radially extended position. The robotic vehicle also includes at least three selectively extendable members extending between the forward and rear housings, for selectively changing the distance between the forward and rear housings to effect movement of the robotic vehicle. 20 figs.

  3. Robotic vehicle

    DOEpatents

    Box, W. Donald

    1998-01-01

    A robotic vehicle for travel through a conduit. The robotic vehicle includes forward and rear housings each having a hub portion, and each being provided with surface engaging mechanisms for selectively engaging the walls of the conduit such that the housings can be selectively held in stationary positions within the conduit. The surface engaging mechanisms of each housing includes a plurality of extendable appendages, each of which is radially extendable relative to the operatively associated hub portion between a retracted position and a radially extended position. The robotic vehicle also includes at least three selectively extendable members extending between the forward and rear housings, for selectively changing the distance between the forward and rear housings to effect movement of the robotic vehicle.

  4. Robotic vehicle

    DOEpatents

    Box, W. Donald

    1997-01-01

    A robotic vehicle for travel through a conduit. The robotic vehicle includes forward and rear housings each having a hub portion, and each being provided with surface engaging mechanisms for selectively engaging the walls of the conduit such that the housings can be selectively held in stationary positions within the conduit. The surface engaging mechanisms of each housing includes a plurality of extendable appendages, each of which is radially extendable relative to the operatively associated hub portion between a retracted position and a radially extended position. The robotic vehicle also includes at least three selectively extendable members extending between the forward and rear housings, for selectively changing the distance between the forward and rear housings to effect movement of the robotic vehicle.

  5. 76 FR 70899 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  6. 78 FR 65212 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  7. 77 FR 41320 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  8. 76 FR 58405 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this ] rule, the suspension will not occur and...

  9. 2 CFR 182.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Suspension. 182.670 Section 182.670 Grants... Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a recipient from... guidance on nonprocurement debarment and suspension (2 CFR part 180, which implements Executive...

  10. 13 CFR 147.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Suspension. 147.670 Section 147...-FREE WORKPLACE (NONPROCUREMENT) Definitions § 147.670 Suspension. Suspension means an action taken by a..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  11. 75 FR 60 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-04

    ... Part 64 [Docket ID FEMA-2008-0020; Internal Agency Docket No. FEMA-8111] Suspension of Community... Insurance Program (NFIP), that are scheduled for suspension on the effective dates listed within this rule... floodplain management measures prior to the effective suspension date given in this rule, the suspension...

  12. 45 CFR 1173.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Suspension. 1173.670 Section 1173.670 Public... (FINANCIAL ASSISTANCE) Definitions § 1173.670 Suspension. Suspension means an action taken by a Federal..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  13. 77 FR 20988 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-09

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  14. 78 FR 70235 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  15. 78 FR 17130 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  16. 49 CFR 32.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Suspension. 32.670 Section 32.670 Transportation... ASSISTANCE) Definitions § 32.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  17. 34 CFR 682.705 - Suspension proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Suspension proceedings. 682.705 Section 682.705... EDUCATION, DEPARTMENT OF EDUCATION FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM Limitation, Suspension, or....705 Suspension proceedings. (a) Scope. (1) A suspension by the Secretary removes a...

  18. 77 FR 68697 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-16

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  19. 22 CFR 1509.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 1509.670 Section 1509.670 Foreign... ASSISTANCE) Definitions § 1509.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  20. 76 FR 5284 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  1. 77 FR 13010 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-05

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  2. 77 FR 57032 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-17

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  3. 78 FR 57523 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-19

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  4. 78 FR 75485 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-12

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  5. 77 FR 28282 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  6. 22 CFR 312.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 312.670 Section 312.670 Foreign... § 312.670 Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a... Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and Executive Order...

  7. 78 FR 57525 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-19

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  8. 78 FR 69001 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  9. 75 FR 49417 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  10. 78 FR 2624 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  11. 29 CFR 1471.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Suspension. 1471.1015 Section 1471.1015 Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1471.1015 Suspension. Suspension is an action taken by a...

  12. 78 FR 5736 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  13. 15 CFR 29.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Suspension. 29.670 Section 29.670... WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 29.670 Suspension. Suspension means an action taken by a..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  14. 76 FR 39782 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  15. 76 FR 14293 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-16

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the ] effective suspension date given in this rule, the suspension will not occur and...

  16. 78 FR 65882 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  17. 76 FR 61954 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-06

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  18. 76 FR 59266 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  19. 78 FR 33989 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  20. 76 FR 45200 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-28

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  1. 29 CFR 98.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Suspension. 98.1015 Section 98.1015 Labor Office of the Secretary of Labor GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 98.1015 Suspension. Suspension is an action taken by a suspending official under subpart G of this part that...

  2. 31 CFR 20.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Suspension. 20.670 Section 20.670...-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.670 Suspension. Suspension means an action taken..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  3. 77 FR 69564 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  4. 77 FR 7537 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-13

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  5. 77 FR 75891 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  6. 29 CFR 1472.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Suspension. 1472.670 Section 1472.670 Labor Regulations... DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1472.670 Suspension. Suspension means an... CFR part 9, subpart 9.4) and the common rule, Government-wide Debarment and Suspension...

  7. 78 FR 17133 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  8. 28 CFR 83.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Suspension. 83.670 Section 83.670... WORKPLACE (GRANTS) Definitions § 83.670 Suspension. Suspension means an action taken by a Federal agency..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  9. 75 FR 24820 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  10. 50 CFR 13.27 - Permit suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Permit suspension. 13.27 Section 13.27... GENERAL PERMIT PROCEDURES Permit Administration § 13.27 Permit suspension. (a) Criteria for suspension... Government. Such suspension shall remain in effect until the issuing officer determines that the...

  11. 24 CFR 1710.45 - Suspensions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Suspensions. 1710.45 Section 1710... Suspensions. (a) Suspension notice—prior to effective date. (1) If it appears to the Secretary that a... Secretary shall so advise the developer, by issuing a suspension notice, within a reasonable time after...

  12. 20 CFR 439.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Suspension. 439.670 Section 439.670 Employees... ASSISTANCE) Definitions § 439.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  13. 78 FR 25582 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-02

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  14. 75 FR 52861 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  15. 78 FR 68999 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  16. 76 FR 9666 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-22

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  17. 76 FR 78164 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-16

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  18. 45 CFR 1155.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Suspension. 1155.670 Section 1155.670 Public... ASSISTANCE) Definitions § 1155.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  19. 78 FR 51076 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-20

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  20. 7 CFR 3021.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Suspension. 3021.670 Section 3021.670 Agriculture... Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a recipient from... Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and Executive Order...

  1. 76 FR 74717 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-01

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  2. 78 FR 2622 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  3. 75 FR 71357 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-23

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  4. 48 CFR 2909.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Suspension. 2909.407... CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 2909.407 Suspension. (a) The Senior... authorized to make an exception, regarding suspension by another agency suspending official under...

  5. 31 CFR 19.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Suspension. 19.1015 Section 19.1015 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 19.1015 Suspension. Suspension is an action taken by a...

  6. 21 CFR 1404.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Suspension. 1404.1015 Section 1404.1015 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1404.1015 Suspension. Suspension is an action taken by a suspending official under subpart G...

  7. 78 FR 54766 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  8. 78 FR 14694 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-07

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  9. 77 FR 43004 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-23

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  10. 49 CFR 570.8 - Suspension systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Suspension systems. 570.8 Section 570.8... Pounds or Less § 570.8 Suspension systems. (a) Suspension condition. Ball joint seals shall not be cut or... out from or missing from suspension joints. Radius rods shall not be missing or damaged....

  11. 78 FR 45460 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-29

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  12. 78 FR 25585 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-02

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  13. 39 CFR 957.27 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Suspension. 957.27 Section 957.27 Postal Service... SUSPENSION FROM CONTRACTING § 957.27 Suspension. (a) Any firm or individual suspended under chapter 3, section 7 of the Postal Service Purchasing Manual who believes that the suspension has not been...

  14. 77 FR 59764 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  15. 78 FR 25589 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-02

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  16. 76 FR 23498 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-27

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  17. 75 FR 63399 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-15

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  18. 75 FR 18408 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-12

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  19. 77 FR 46968 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-07

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  20. 22 CFR 1006.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 1006.1015 Section 1006.1015 Foreign Relations INTER-AMERICAN FOUNDATION GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1006.1015 Suspension. Suspension is an action taken by a suspending official under subpart G of...

  1. 43 CFR 43.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Suspension. 43.670 Section 43.670 Public... WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 43.670 Suspension. Suspension means an action taken by a..., subpart 9.4) and 2 CFR part 180. Suspension of a recipient is a distinct and separate action...

  2. 41 CFR 105-68.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Suspension. 105-68.1015 Section 105-68.1015 Public Contracts and Property Management Federal Property Management Regulations...-GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 105-68.1015 Suspension. Suspension is...

  3. 75 FR 35666 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  4. 75 FR 14356 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-25

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  5. 14 CFR 1267.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Suspension. 1267.670 Section 1267.670... WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1267.670 Suspension. Suspension means an action taken by a..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  6. 78 FR 5734 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  7. 77 FR 59762 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  8. 49 CFR 238.427 - Suspension system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Suspension system. 238.427 Section 238.427... Equipment § 238.427 Suspension system. (a) General requirements. (1) Suspension systems shall be designed to... equipment. (2) Passenger equipment shall meet the safety performance standards for suspension...

  9. 2 CFR 180.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Suspension. 180.1015 Section 180.1015 Grants... Reserved OMB GUIDELINES TO AGENCIES ON GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 180.1015 Suspension. Suspension is an action taken by a suspending official under subpart G of...

  10. 77 FR 36172 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  11. 76 FR 67372 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-01

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  12. 78 FR 79324 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  13. 76 FR 2596 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  14. 75 FR 55683 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  15. 77 FR 2646 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-19

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  16. 77 FR 2650 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-19

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  17. 34 CFR 85.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Suspension. 85.1015 Section 85.1015 Education Office of the Secretary, Department of Education GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 85.1015 Suspension. Suspension is an action taken by a suspending official under subpart G...

  18. 78 FR 45462 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-29

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  19. 45 CFR 1206.1-4 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Suspension. 1206.1-4 Section 1206.1-4 Public... GRANTS AND CONTRACTS-SUSPENSION AND TERMINATION AND DENIAL OF APPLICATION FOR REFUNDING Suspension and Termination of Assistance § 1206.1-4 Suspension. (a) General. The responsible Corporation official may...

  20. 78 FR 54770 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  1. 77 FR 24858 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  2. 75 FR 9111 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-01

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  3. 22 CFR 208.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Suspension. 208.1015 Section 208.1015 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 208.1015 Suspension. Suspension is an action taken by a suspending official under subpart G...

  4. 29 CFR 94.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Suspension. 94.670 Section 94.670 Labor Office of the... § 94.670 Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a... Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and Executive Order...

  5. 76 FR 56117 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-12

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  6. 7 CFR 3017.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Suspension. 3017.1015 Section 3017.1015 Agriculture... AGRICULTURE GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 3017.1015 Suspension. Suspension is an action taken by a suspending official under subpart G of this part that...

  7. 31 CFR 10.82 - Expedited suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Expedited suspension. 10.82 Section... INTERNAL REVENUE SERVICE Rules Applicable to Disciplinary Proceedings § 10.82 Expedited suspension. (a... suspension. A suspension under this section will commence on the date that written notice of the...

  8. 78 FR 37978 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-25

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  9. 24 CFR 21.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Suspension. 21.670 Section 21.670... GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (GRANTS) Definitions § 21.670 Suspension. Suspension means an... CFR part 9, subpart 9.4) and the common rule, Government-wide Debarment and Suspension...

  10. 21 CFR 1405.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Suspension. 1405.670 Section 1405.670 Food and... (FINANCIAL ASSISTANCE) Definitions § 1405.670 Suspension. Suspension means an action taken by a Federal..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  11. 75 FR 44152 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-28

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  12. 76 FR 18934 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-06

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  13. 75 FR 28492 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-21

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  14. 77 FR 9856 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  15. 5 CFR 919.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Suspension. 919.1015 Section 919.1015 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 919.1015 Suspension. Suspension is...

  16. 75 FR 32302 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  17. 75 FR 19891 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-16

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  18. 22 CFR 1508.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 1508.1015 Section 1508.1015 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1508.1015 Suspension. Suspension is an action taken by a suspending official under subpart G...

  19. 75 FR 5890 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-05

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  20. 75 FR 52865 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  1. 22 CFR 210.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Suspension. 210.670 Section 210.670 Foreign... (FINANCIAL ASSISTANCE) Definitions § 210.670 Suspension. Suspension means an action taken by a Federal agency..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  2. 45 CFR 1641.11 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Suspension. 1641.11 Section 1641.11 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES CORPORATION DEBARMENT, SUSPENSION AND REMOVAL OF RECIPIENT AUDITORS Suspension § 1641.11 Suspension. (a) IPAs suspended from providing...

  3. 49 CFR 570.61 - Suspension system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Suspension system. 570.61 Section 570.61... 10,000 Pounds § 570.61 Suspension system. (a) Suspension condition. Ball joint seals shall not be cut... bushings shall not be cracked, extruded out from or missing from suspension joints. Radius rods shall...

  4. 22 CFR 133.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Suspension. 133.670 Section 133.670 Foreign... ASSISTANCE) Definitions § 133.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  5. 76 FR 34611 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  6. 22 CFR 1008.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 1008.670 Section 1008.670 Foreign... ASSISTANCE) Definitions § 1008.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  7. 10 CFR 607.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Suspension. 607.670 Section 607.670 Energy DEPARTMENT OF... ASSISTANCE) Definitions § 607.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  8. 45 CFR 630.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Suspension. 630.670 Section 630.670 Public Welfare... DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 630.670 Suspension. Suspension means an action... CFR part 9, subpart 9.4) and the common rule, Government-wide Debarment and Suspension...

  9. 75 FR 80351 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-22

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  10. 75 FR 57688 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-22

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  11. 77 FR 53775 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  12. 34 CFR 84.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Suspension. 84.670 Section 84.670 Education Office of... ASSISTANCE) Definitions § 84.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  13. Interagency Suspension and Debarment Committee

    EPA Pesticide Factsheets

    The Interagency Suspension and Debarment Committee (ISDC) was created, as an Office of Management and Budget (OMB) committee, by Executive Order 12549 for the purpose of monitoring the implementation of the Order.

  14. Suspension of Registrations under FIFRA

    EPA Pesticide Factsheets

    Under FIFRA Section 3(c)(2)(B), this generally halts further distribution and sale of the suspended pesticide product by the registrant. Find suspension listings by product name, active ingredient, registrant name, date, and contact information.

  15. Extensional rheology of active suspensions

    NASA Astrophysics Data System (ADS)

    Saintillan, David

    2010-05-01

    A simple model is presented for the effective extensional rheology of a dilute suspension of active particles, such as self-propelled microswimmers, extending previous classical studies on suspensions of passive rodlike particles. Neglecting particle-particle hydrodynamic interactions, we characterize the configuration of the suspension by an orientation distribution, which satisfies a Fokker-Planck equation including the effects of an external flow field and of rotary diffusion. Knowledge of this orientation distribution then allows the determination of the particle extra stress as a configurational average of the force dipoles exerted by the particles on the fluid, which involve contributions from the imposed flow, rotary diffusion, and the permanent dipoles resulting from activity. Analytical expressions are obtained for the stress tensor in uniaxial extensional and compressional flows, as well as in planar extensional flow. In all types of flows, the effective viscosity is found to increase as a result of activity in suspensions of head-actuated swimmers (pullers) and to decrease in suspensions of tail-actuated swimmers (pushers). In the latter case, a negative particle viscosity is found to occur in weak flows. In planar extensional flow, we also characterize normal stresses, which are enhanced by activity in suspensions of pullers but reduced in suspensions of pushers. Finally, an energetic interpretation of the seemingly unphysical decrease in viscosity predicted in suspensions of pushers is proposed, where the decrease is explained as a consequence of the active power input generated by the swimming particles and is shown not to be directly related to viscous dissipative processes.

  16. Debarment and suspension. [of contractors

    NASA Technical Reports Server (NTRS)

    Whelan, Thomas J.

    1987-01-01

    The changing Government attitude toward contractor debarment and suspension is examined, with emphasis on the fact that the Government is more alert to fraud, waste, and abuse. Consideration is given to causes of debarment or suspension, procedures and due process hearings, settlement agreements, compliance programs, and recent related legislation. It is concluded that the change in the Government contracting environment in recent years should be sufficient incentive for contractors to monitor their operations more closely.

  17. Extensional rheology of active suspensions.

    PubMed

    Saintillan, David

    2010-05-01

    A simple model is presented for the effective extensional rheology of a dilute suspension of active particles, such as self-propelled microswimmers, extending previous classical studies on suspensions of passive rodlike particles. Neglecting particle-particle hydrodynamic interactions, we characterize the configuration of the suspension by an orientation distribution, which satisfies a Fokker-Planck equation including the effects of an external flow field and of rotary diffusion. Knowledge of this orientation distribution then allows the determination of the particle extra stress as a configurational average of the force dipoles exerted by the particles on the fluid, which involve contributions from the imposed flow, rotary diffusion, and the permanent dipoles resulting from activity. Analytical expressions are obtained for the stress tensor in uniaxial extensional and compressional flows, as well as in planar extensional flow. In all types of flows, the effective viscosity is found to increase as a result of activity in suspensions of head-actuated swimmers (pullers) and to decrease in suspensions of tail-actuated swimmers (pushers). In the latter case, a negative particle viscosity is found to occur in weak flows. In planar extensional flow, we also characterize normal stresses, which are enhanced by activity in suspensions of pullers but reduced in suspensions of pushers. Finally, an energetic interpretation of the seemingly unphysical decrease in viscosity predicted in suspensions of pushers is proposed, where the decrease is explained as a consequence of the active power input generated by the swimming particles and is shown not to be directly related to viscous dissipative processes.

  18. Time response analysis in suspension system design of a high-speed car

    NASA Astrophysics Data System (ADS)

    Pagwiwoko, Cosmas Pandit

    2010-03-01

    A land speed record vehicle is designed to run on a flat surface like salt lake where the wheels are normally made from solid metal with a special suspension system. The suspension is designed to provide a stable platform to keep the wheel treads on tract, to insulate the car and the driver from the surface irregularities and to take part of good handling properties. The surface condition of the lake beds is basically flat without undulations but with inconsistent surface textures and ridges. Spring with nonlinear rate is used with the reason that the resistance builds up roughly proportional to the aerodynamic download for keeping the height more nearly constant. The objective of the work is to produce an efficient method for assisting the design of suspension system. At the initial step, the stiffness and the damping constants are determined based on RMS optimization by following the optimization strategy i.e. to minimize the absolute acceleration respect to the relative displacement of the suspension. Power bond graph technique is then used to model the nonlinearity of the components i.e. spring and dashpot of the suspension system. This technique also enables to incorporate the interactions of dynamic response of the vehicle's body with aerodynamic flow as a result of the base excitation of the ground to the wheels. The simulation is conducted on the platform of Simulink-MATLAB and the interactions amongst the components within the system are observed in time domain to evaluate the effectiveness of the suspension.

  19. Time response analysis in suspension system design of a high-speed car

    NASA Astrophysics Data System (ADS)

    Pagwiwoko, Cosmas Pandit

    2009-12-01

    A land speed record vehicle is designed to run on a flat surface like salt lake where the wheels are normally made from solid metal with a special suspension system. The suspension is designed to provide a stable platform to keep the wheel treads on tract, to insulate the car and the driver from the surface irregularities and to take part of good handling properties. The surface condition of the lake beds is basically flat without undulations but with inconsistent surface textures and ridges. Spring with nonlinear rate is used with the reason that the resistance builds up roughly proportional to the aerodynamic download for keeping the height more nearly constant. The objective of the work is to produce an efficient method for assisting the design of suspension system. At the initial step, the stiffness and the damping constants are determined based on RMS optimization by following the optimization strategy i.e. to minimize the absolute acceleration respect to the relative displacement of the suspension. Power bond graph technique is then used to model the nonlinearity of the components i.e. spring and dashpot of the suspension system. This technique also enables to incorporate the interactions of dynamic response of the vehicle's body with aerodynamic flow as a result of the base excitation of the ground to the wheels. The simulation is conducted on the platform of Simulink-MATLAB and the interactions amongst the components within the system are observed in time domain to evaluate the effectiveness of the suspension.

  20. Stowable Energy-Absorbing Rocker-Bogie Suspensions

    NASA Technical Reports Server (NTRS)

    Harrington, Brian; Voorhees, Christopher

    2007-01-01

    A report discusses the design of the rocker-bogie suspensions of the Mars Exploration Rover vehicles, which were landed on Mars in January 2004. Going beyond the basic requirements regarding mobility on uneven terrain, the design had to satisfy requirements (1) to enable each suspension to contort so that the rover could be stowed within limited space in a tetrahedral lander prior to deployment and (2) that the suspension be able to absorb appreciable impact loads, with limited deflection, during egress from the lander and traversal of terrain. For stowability, six joints (three on the right, three on the left) were added to the basic rocker-bogie mechanism. One of the joints on each side was a yoke-and-clevis joint at the suspension/differential interface, one was a motorized twist joint in the forward portion of the rocker, and one was a linear joint created by modifying a fixed-length bogie member into a telescoping member. For absorption of impact, the structural members were in the form of box beams made by electron-beam welding of machined, thin-walled, C-channel, titanium components. The box beams were very lightweight and could withstand high bending and torsional loads.

  1. The suspension balance model revisited

    NASA Astrophysics Data System (ADS)

    Nott, Prabhu R.; Guazzelli, Elisabeth; Pouliquen, Olivier

    2011-04-01

    This paper addresses a fundamental discrepancy between the suspension balance model and other two-phase flow formulations. The former was proposed to capture the shear-induced migration of particles in Stokesian suspensions, and hinges on the presence of a particle phase stress to drive particle migration. This stress is taken to be the "particle stress," defined as the particle contribution to the suspension stress. On the other hand, the two-phase flow equations derived in several studies show only a force acting on the particle phase, but no stress. We show that the identification of the particle phase stress with the particle contribution to the suspension stress in the suspension balance model is incorrect, but there exists a well-defined particle phase stress. Following the rigorous method of volume averaging, we show that the force on the particle phase may be written as the sum of an interphase drag and the divergence of the particle phase stress. We derive exact micromechanical relations for these quantities. We also comment on the interpretations and results of previous studies that are based on the identification of the particle phase stress with the particle contribution to the suspension stress.

  2. Railway vehicle performance optimisation using virtual homologation

    NASA Astrophysics Data System (ADS)

    Magalhães, H.; Madeira, J. F. A.; Ambrósio, J.; Pombo, J.

    2016-09-01

    Unlike regular automotive vehicles, which are designed to travel in different types of roads, railway vehicles travel mostly in the same route during their life cycle. To accept the operation of a railway vehicle in a particular network, a homologation process is required according to local standard regulations. In Europe, the standards EN 14363 and UIC 518, which are used for railway vehicle acceptance, require on-track tests and/or numerical simulations. An important advantage of using virtual homologation is the reduction of the high costs associated with on-track tests by studying the railway vehicle performance in different operation conditions. This work proposes a methodology for the improvement of railway vehicle design with the objective of its operation in selected railway tracks by using optimisation. The analyses required for the vehicle improvement are performed under control of the optimisation method global and local optimisation using direct search. To quantify the performance of the vehicle, a new objective function is proposed, which includes: a Dynamic Performance Index, defined as a weighted sum of the indices obtained from the virtual homologation process; the non-compensated acceleration, which is related to the operational velocity; and a penalty associated with cases where the vehicle presents an unacceptable dynamic behaviour according to the standards. Thus, the optimisation process intends not only to improve the quality of the vehicle in terms of running safety and ride quality, but also to increase the vehicle availability via the reduction of the time for a journey while ensuring its operational acceptance under the standards. The design variables include the suspension characteristics and the operational velocity of the vehicle, which are allowed to vary in an acceptable range of variation. The results of the optimisation lead to a global minimum of the objective function in which the suspensions characteristics of the vehicle are

  3. 32 CFR 634.11 - Administrative due process for suspensions and revocations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... drunk driving or driving under the influence offenses, reliable evidence readily available will be.... (9) Hearing on suspension actions under § 634.9(a) for drunk or impaired driving pending resolution... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving...

  4. 32 CFR 634.11 - Administrative due process for suspensions and revocations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... drunk driving or driving under the influence offenses, reliable evidence readily available will be.... (9) Hearing on suspension actions under § 634.9(a) for drunk or impaired driving pending resolution... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving...

  5. 32 CFR 634.11 - Administrative due process for suspensions and revocations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... drunk driving or driving under the influence offenses, reliable evidence readily available will be.... (9) Hearing on suspension actions under § 634.9(a) for drunk or impaired driving pending resolution... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving...

  6. 32 CFR 634.11 - Administrative due process for suspensions and revocations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... drunk driving or driving under the influence offenses, reliable evidence readily available will be.... (9) Hearing on suspension actions under § 634.9(a) for drunk or impaired driving pending resolution... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving...

  7. 32 CFR 634.11 - Administrative due process for suspensions and revocations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... drunk driving or driving under the influence offenses, reliable evidence readily available will be.... (9) Hearing on suspension actions under § 634.9(a) for drunk or impaired driving pending resolution... (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving...

  8. Pre-Alignment Checks. Automotive Mechanics. Steering & Suspension. Instructor's Guide [and] Student Guide.

    ERIC Educational Resources Information Center

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automotive steering and suspension, consists of a student guide and an instructor guide dealing with prealignment checks. Covered in the module are the following steps in a prealignment check: checking the ride height of a vehicle, checking the ball joints and the…

  9. Hydraulic actuation technology for full- and semi-active railway suspensions

    NASA Astrophysics Data System (ADS)

    Goodall, Roger; Freudenthaler, Gerhard; Dixon, Roger

    2014-12-01

    The paper describes a simulation study that provides a comprehensive comparison between full-active and semi-active suspensions for improving the vertical ride quality of railway vehicles. It includes an assessment of the ride quality benefits that can theoretically be achieved with idealised devices, and also examines the impact of real devices based upon hydraulic actuation technology.

  10. Method and apparatus for analyzing particle-containing gaseous suspensions

    DOEpatents

    Solomon, Peter R.; Carangelo, Robert M.; Best, Philip E.

    1987-01-01

    The method and apparatus permit analyses, by optical means, of properties of gaseous suspensions of particles, by measuring radiation that is emitted, transmitted or scattered by the particles. Determinations of composition, size, temperature and spectral emittance can be performed either in-situ or by sampling, and Fourier-transform infrared spectrometric techniques are most effectively used. Apparatus specifically adapted for performing radiation scattering analyses, and for collecting radiation from different sources, are provided.

  11. Method and apparatus for analyzing particle-containing gaseous suspensions

    DOEpatents

    Solomon, P.R.; Carangelo, R.M.; Best, P.E.

    1987-03-24

    The method and apparatus permit analyses, by optical means, of properties of gaseous suspensions of particles, by measuring radiation that is emitted, transmitted or scattered by the particles. Determinations of composition, size, temperature and spectral emittance can be performed either in-situ or by sampling, and Fourier-transform infrared spectrometric techniques are most effectively used. Apparatus specifically adapted for performing radiation scattering analyses, and for collecting radiation from different sources, are provided. 51 figs.

  12. The Challenges of Designing the Rocker-Bogie Suspension for the Mars Exploration Rover

    NASA Technical Reports Server (NTRS)

    Harrington, Brian D.; Voorhees, Chris

    2004-01-01

    Over the past decade, the rocker-bogie suspension design has become a proven mobility application known for its superior vehicle stability and obstacle-climbing capability. Following several technology and research rover implementations, the system was successfully flown as part of Mars Pathfinder s Sojourner rover. When the Mars Exploration Rover (MER) Project was first proposed, the use of a rocker-bogie suspension was the obvious choice due to its extensive heritage. The challenge posed by MER was to design a lightweight rocker-bogie suspension that would permit the mobility to stow within the limited space available and deploy into a configuration that the rover could then safely use to egress from the lander and explore the Martian surface. This paper will describe how the MER rocker-bogie suspension subsystem was able to meet these conflicting design requirements while highlighting the variety of deployment and latch mechanisms employed in the design.

  13. Suspension biomechanics of swimming microbes

    PubMed Central

    Ishikawa, Takuji

    2009-01-01

    Micro-organisms play a vital role in many biological, medical and engineering phenomena. Some recent research efforts have demonstrated the importance of biomechanics in understanding certain aspects of micro-organism behaviours such as locomotion and collective motions of cells. In particular, spatio-temporal coherent structures found in a bacterial suspension have been the focus of many research studies over the last few years. Recent studies have shown that macroscopic properties of a suspension, such as rheology and diffusion, are strongly affected by meso-scale flow structures generated by swimming microbes. Since the meso-scale flow structures are strongly affected by the interactions between microbes, a bottom-up strategy, i.e. from a cellular level to a continuum suspension level, represents the natural approach to the study of a suspension of swimming microbes. In this paper, we first provide a summary of existing biomechanical research on interactions between a pair of swimming micro-organisms, as a two-body interaction is the simplest many-body interaction. We show that interactions between two nearby swimming micro-organisms are described well by existing mathematical models. Then, collective motions formed by a group of swimming micro-organisms are discussed. We show that some collective motions of micro-organisms, such as coherent structures of bacterial suspensions, are satisfactorily explained by fluid dynamics. Lastly, we discuss how macroscopic suspension properties are changed by the microscopic characteristics of the cell suspension. The fundamental knowledge we present will be useful in obtaining a better understanding of the behaviour of micro-organisms. PMID:19674997

  14. Automated Vehicle Regulation: An Energy and Emissions Perspective

    SciTech Connect

    Levine, Aaron

    2016-05-18

    This presentation provides a summary of the current automated vehicles polices in the United States and how they related to reducing greenhouse gas (GHG) emissions. The presentation then looks at future automated vehicle trends that will increase and reduce GHG emissions and what current policies utilized in other areas of law could be adapted for automated vehicle GHG emissions.

  15. Heavy and Overweight Vehicle Defects Interim Report

    SciTech Connect

    Siekmann, Adam; Capps, Gary J

    2012-12-01

    The Federal Highway Administration (FHWA), along with the Federal Motor Carrier Safety Administration (FMCSA), has an interest in overweight commercial motor vehicles, how they affect infrastructure, and their impact on safety on the nation s highways. To assist both FHWA and FMCSA in obtaining more information related to this interest, data was collected and analyzed from two separate sources. A large scale nationwide data collection effort was facilitated by the Commercial Vehicle Safety Alliance as part of a special study on overweight vehicles and an additional, smaller set, of data was collected from the state of Tennessee which included a much more detailed set of data. Over a six-month period, 1,873 Level I inspections were performed in 18 different states that volunteered to be a part of this study. Of the 1,873 inspections, a vehicle out-of-service (OOS) violation was found on 44.79% of the vehicles, a rate significantly higher than the national OOS rate of 27.23%. The main cause of a vehicle being placed OOS was brake-related defects, with approximately 30% of all vehicles having an OOS brake violation. Only about 4% of vehicles had an OOS tire violation, and even fewer had suspension and wheel violations. Vehicle weight violations were most common on an axle group as opposed to a gross vehicle weight violation. About two thirds of the vehicles cited with a weight violation were overweight on an axle group with an average amount of weight over the legal limit of about 2,000 lbs. Data collection is scheduled to continue through January 2014, with more potentially more states volunteering to collect data. More detailed data collections similar to the Tennessee data collection will also be performed in multiple states.

  16. Robotic vehicle

    DOEpatents

    Box, W.D.

    1994-03-15

    A robotic vehicle is described for travel through an enclosed or partially enclosed conduit or pipe including vertical and/or horizontal conduit or pipe. The robotic vehicle comprises forward and rear housings each provided with a surface engaging mechanism for selectively engaging the walls of the conduit through which the vehicle is travelling, whereby the housings are selectively held in a stationary position within the conduit. The vehicle also includes at least three selectively extendable members, each of which defines a cavity therein. The forward end portion of each extendable member is secured to the forward housing and the rear end portion of each housing is secured to the rear housing. Each of the extendable members is independently extendable from a retracted position to an extended position upon the injection of a gas under pressure into the cavity of the extendable member such that the distance between the forward housing and the rear housing can be selectively increased. Further, each of the extendable members is independently retractable from the extended position to the retracted position upon the application of a vacuum to the cavity of the extendable member such that the distance between the forward housing and the rear housing can be selectively decreased. 11 figures.

  17. Robotic vehicle

    DOEpatents

    Box, W.D.

    1996-03-12

    A robotic vehicle is described for travel through an enclosed or partially enclosed conduit or pipe including vertical and/or horizontal conduit or pipe. The robotic vehicle comprises forward and rear housings each provided with a surface engaging mechanism for selectively engaging the walls of the conduit through which the vehicle is travelling, whereby the housings are selectively held in a stationary position within the conduit. The vehicle also includes at least three selectively extendable members, each of which defines a cavity therein. The forward end portion of each extendable member is secured to the forward housing and the rear end portion of each housing is secured to the rear housing. Each of the extendable members is independently extendable from a retracted position to an extended position upon the injection of a gas under pressure into the cavity of the extendable member such that the distance between the forward housing and the rear housing can be selectively increased. Further, each of the extendable members is independently retractable from the extended position to the retracted position upon the application of a vacuum to the cavity of the extendable member such that the distance between the forward housing and the rear housing can be selectively decreased. 14 figs.

  18. Robotic vehicle

    DOEpatents

    Box, W. Donald

    1996-01-01

    A robotic vehicle (10) for travel through an enclosed or partially enclosed conduit or pipe including vertical and/or horizontal conduit or pipe. The robotic vehicle (10) comprises forward and rear housings (32 and 12) each provided with a surface engaging mechanism for selectively engaging the walls of the conduit through which the vehicle is travelling, whereby the housings (32 and 12) are selectively held in a stationary position within the conduit. The vehicle (10) also includes at least three selectively extendable members (46), each of which defines a cavity (56) therein. The forward end portion (50) of each extendable member (46) is secured to the forward housing (32) and the rear end portion (48) of each housing is secured to the rear housing (12). Each of the extendable members (46) is independently extendable from a retracted position to an extended position upon the injection of a gas under pressure into the cavity (56) of the extendable member such that the distance between the forward housing (32 ) and the rear housing (12) can be selectively increased. Further, each of the extendable members (46) is independently retractable from the extended position to the retracted position upon the application of a vacuum to the cavity (56) of the extendable member (46) such that the distance between the forward housing (32) and the rear housing (12) can be selectively decreased.

  19. Robotic vehicle

    DOEpatents

    Box, W. Donald

    1994-01-01

    A robotic vehicle (10) for travel through an enclosed or partially enclosed conduit or pipe including vertical and/or horizontal conduit or pipe. The robotic vehicle (10) comprises forward and rear housings (32 and 12) each provided with a surface engaging mechanism for selectively engaging the walls of the conduit through which the vehicle is travelling, whereby the housings (32 and 12) are selectively held in a stationary position within the conduit. The vehicle (10) also includes at least three selectively extendable members (46), each of which defines a cavity (56) therein. The forward end portion (50) of each extendable member (46) is secured to the forward housing (32) and the rear end portion (48) of each housing is secured to the rear housing (12). Each of the extendable members (46) is independently extendable from a retracted position to an extended position upon the injection of a gas under pressure into the cavity (56) of the extendable member such that the distance between the forward housing (32 ) and the rear housing (12) can be selectively increased. Further, each of the extendable members (46) is independently retractable from the extended position to the retracted position upon the application of a vacuum to the cavity (56) of the extendable member (46) such that the distance between the forward housing (32) and the rear housing (12) can be selectively decreased.

  20. A Multidisciplinary Optimization Framework for Occupant Centric Ground Vehicle System Design. Part 1: Vehicle Design Parameter Screening Study

    DTIC Science & Technology

    2014-08-01

    shell components. The effects of suspension components on blast loading to a vehicle structure are assumed to be minimal. Therefore, the vehicle...seating mount position rigidly. There is no foot rest included in the model. In the underbody blast modeling and simulation, the cylindrical charge is...assembly and reinforcement structure. The crew cabin is a hull of a box shape with four side walls, a roof attached to the top of the box, and a crew