Science.gov

Sample records for actual vehicle speed

  1. Vehicle speed control device

    SciTech Connect

    Thornton-Trump, W.E.

    1987-03-10

    An apparatus is described for automatically limiting the speed of a vehicle powered by an internal combustion engine having a spark ignition system with an ignition coil, comprising: sensor means for generating a speed signal directly representative of the speed of the vehicle comprising a series of speed signal pulses having a pulse repetition frequency proportional to the speed of the vehicle; control means for converting speed signal pulses into a DC voltage proportional to the vehicle speed; means for comparing the DC voltage to a predetermined DC voltage having substantially zero AC components representative of a predetermined maximum speed and for generating a difference signal in response thereto; and means for generating a pulse-width modulated control signal responsive to the difference signal; power means responsive to the control signal for intermittently interrupting the ignition system.

  2. Systems and methods for vehicle speed management

    DOEpatents

    Sujan, Vivek Anand; Vajapeyazula, Phani; Follen, Kenneth; Wu, An; Forst, Howard Robert

    2016-03-01

    Controlling a speed of a vehicle based on at least a portion of a route grade and a route distance divided into a plurality of route sections, each including at least one of a section grade and section length. Controlling the speed of the vehicle is further based on determining a cruise control speed mode for the vehicle for each of the plurality of route sections and determining a speed reference command of the vehicle based on at least one of the cruise control speed mode, the section length, the section grade, and a current speed.

  3. An inexpensive vehicle speed detector

    NASA Technical Reports Server (NTRS)

    Broussard, P., Jr.

    1973-01-01

    Low-power minicomputer can plug into automobile cigarette lighter. It measures time it takes observed car to travel premeasured distance and provides immediate readout of speed. Potentially, detector could be manufactured for less than $200 per unit and would have very low maintenance cost.

  4. Enforcement of speed limits--actual policy and drivers' knowledge.

    PubMed

    Jørgensen, Finn; Pedersen, Hassa

    2005-01-01

    This paper reviews the penalty rules and examines drivers' perceptions of enforcement of speed limits. The survey was carried out using a sample of 204 Norwegian drivers, answering questions in a setting closely associated with their driving situation. For minor speeding offences drivers overestimated on average their fines. For serious speeding offences drivers significantly underestimated how many kilometers per hour they could exceed the speed limits before losing their driving license. They also overestimated the probability of being caught speeding. This resulted in a perceived expected penalty twice the real one. The paper also examines the relationship between different driver characteristics and their knowledge of the enforcement policy for speeding. Older drivers had less knowledge about the threshold level for serious speeding but more knowledge about the detection rate than younger drivers do. Experienced drivers had more knowledge about the threshold level for serious speeding than inexperienced drivers. The number of times drivers were stopped due to speeding offences increased their knowledge of fines for minor speeding.

  5. 40 CFR 1037.640 - Variable vehicle speed limiters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Variable vehicle speed limiters. 1037... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Special Compliance Provisions § 1037.640 Variable vehicle speed limiters. This section specifies provisions that apply for...

  6. 40 CFR 1037.640 - Variable vehicle speed limiters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Variable vehicle speed limiters. 1037... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES Special Compliance Provisions § 1037.640 Variable vehicle speed limiters. This section specifies provisions that apply for...

  7. Discrepancy between actual and estimated speeds of drivers in the presence of child pedestrians

    PubMed Central

    Harre, N

    2003-01-01

    Objectives: First, to measure the speeds of vehicles with and without children on the footpath, and second to compare these with drivers' estimates of how fast they would go in these conditions. Design: The speeds of vehicles in three conditions: control (no children present), children playing with a ball on the footpath, and children waiting to cross the road, were measured using speed tubes during two 55 minute sessions. Drivers' estimates of their speeds were measured with a questionnaire. Setting: Speeds were measured on a main road in Auckland, New Zealand. The questionnaire was conducted at another time with drivers stopping for petrol approximately 500 metres from the measurement site. Subjects: A total of 1446 speed measurements were taken and 93 drivers‘ questionnaire responses were analysed. Results: The mean free speed of vehicles in the control condition was 55.60 kph, with drivers‘ estimates being 56.37 kph. When children were playing with a ball the measured speed was 54.29 kph and the estimated speed 39.27 kph. When children were waiting to cross the measured speed was 52.78 kph, estimated speed 34.02 kph. Analyses indicated that there were significant differences between measured and estimated speeds. Conclusions: New Zealand drivers make inadequate speed adjustments in the presence of children, despite probably believing they do so. Establishing specific rules about appropriate speeds around children and highlighting to drivers the discrepancy between their attitudes and behaviour are two intervention strategies suggested. PMID:12642557

  8. Two speed drive system. [mechanical device for changing speed on rotating vehicle wheel

    NASA Technical Reports Server (NTRS)

    Burch, J. L. (Inventor)

    1972-01-01

    A two speed drive system for a wheel of a vehicle by which shifting from one speed to the other is accomplished by the inherent mechanism of the wheel is described. A description of the speed shifting operation is provided and diagrams of the mechanism are included. Possible application to lunar roving vehicles is proposed.

  9. Research on motor rotational speed measurement in regenerative braking system of electric vehicle

    NASA Astrophysics Data System (ADS)

    Pan, Chaofeng; Chen, Liao; Chen, Long; Jiang, Haobin; Li, Zhongxing; Wang, Shaohua

    2016-01-01

    Rotational speed signals acquisition and processing techniques are widely used in rotational machinery. In order to realized precise and real-time control of motor drive and regenerative braking process, rotational speed measurement techniques are needed in electric vehicles. Obtaining accurate motor rotational speed signal will contribute to the regenerative braking force control steadily and realized higher energy recovery rate. This paper aims to develop a method that provides instantaneous speed information in the form of motor rotation. It addresses principles of motor rotational speed measurement in the regenerative braking systems of electric vehicle firstly. The paper then presents ideal and actual Hall position sensor signals characteristics, the relation between the motor rotational speed and the Hall position sensor signals is revealed. Finally, Hall position sensor signals conditioning and processing circuit and program for motor rotational speed measurement have been carried out based on measurement error analysis.

  10. Speed kills: ineffective avian escape responses to oncoming vehicles

    PubMed Central

    DeVault, Travis L.; Blackwell, Bradley F.; Seamans, Thomas W.; Lima, Steven L.; Fernández-Juricic, Esteban

    2015-01-01

    Animal–vehicle collisions cause high levels of vertebrate mortality worldwide, and what goes wrong when animals fail to escape and ultimately collide with vehicles is not well understood. We investigated alert and escape behaviours of captive brown-headed cowbirds (Molothrus ater) in response to virtual vehicle approaches of different sizes and at speeds ranging from 60 to 360 km h−1. Alert and flight initiation distances remained similar across vehicle speeds, and accordingly, alert and flight initiation times decreased at higher vehicle speeds. Thus, avoidance behaviours in cowbirds appeared to be based on distance rather than time available for escape, particularly at 60–150 km h−1; however, at higher speeds (more than or equal to 180 km h−1) no trend in response behaviour was discernible. As vehicle speed increased, cowbirds did not have enough time to assess the approaching vehicle, and cowbirds generally did not initiate flight with enough time to avoid collision when vehicle speed exceeded 120 km h−1. Although potentially effective for evading predators, the decision-making process used by cowbirds in our study appears maladaptive in the context of avoiding fast-moving vehicles. Our methodological approach and findings provide a framework to assess how novel management strategies could affect escape rules, and the sensory and cognitive abilities animals use to avoid vehicle collisions. PMID:25567648

  11. Penetrating injury from high-speed motor vehicle collision.

    PubMed

    Daniels, Alan H

    2015-01-01

    We present the case history of a post motor vehicle crash victim with lower extremity fractures and decreased blood flow. Emergent Angipgraphy revealed a foreign body which was later operated and removed. The case emphasizes that High-speed motor vehicle accidents commonly lead to penetrating injury from objects within and outside of the vehicle.

  12. Calibration of GPS based high accuracy speed meter for vehicles

    NASA Astrophysics Data System (ADS)

    Bai, Yin; Sun, Qiao; Du, Lei; Yu, Mei; Bai, Jie

    2015-02-01

    GPS based high accuracy speed meter for vehicles is a special type of GPS speed meter which uses Doppler Demodulation of GPS signals to calculate the speed of a moving target. It is increasingly used as reference equipment in the field of traffic speed measurement, but acknowledged standard calibration methods are still lacking. To solve this problem, this paper presents the set-ups of simulated calibration, field test signal replay calibration, and in-field test comparison with an optical sensor based non-contact speed meter. All the experiments were carried out on particular speed values in the range of (40-180) km/h with the same GPS speed meter. The speed measurement errors of simulated calibration fall in the range of +/-0.1 km/h or +/-0.1%, with uncertainties smaller than 0.02% (k=2). The errors of replay calibration fall in the range of +/-0.1% with uncertainties smaller than 0.10% (k=2). The calibration results justify the effectiveness of the two methods. The relative deviations of the GPS speed meter from the optical sensor based noncontact speed meter fall in the range of +/-0.3%, which validates the use of GPS speed meter as reference instruments. The results of this research can provide technical basis for the establishment of internationally standard calibration methods of GPS speed meters, and thus ensures the legal status of GPS speed meters as reference equipment in the field of traffic speed metrology.

  13. Design criteria for light high speed desert air cushion vehicles

    NASA Astrophysics Data System (ADS)

    Abulnaga, B. E.

    An evaluation is made of the applicability and prospective performance of ACVs in trans-Saharan cargo transport, in view of the unique characteristics of the dry sand environment. The lightweight/high-speed ACV concept envisioned is essentially ground effect aircraftlike, with conventional wheels as a low-speed backup suspension system. A propeller is used in ground effect cruise. Attention is given to the effects on vehicle stability and performance of sandy surface irregularities of the desert topography and of cross-winds from various directions relative to vehicle movement.

  14. Changes in speed distribution: Applying aggregated safety effect models to individual vehicle speeds.

    PubMed

    Vadeby, Anna; Forsman, Åsa

    2017-03-31

    This study investigated the effect of applying two aggregated models (the Power model and the Exponential model) to individual vehicle speeds instead of mean speeds. This is of particular interest when the measure introduced affects different parts of the speed distribution differently. The aim was to examine how the estimated overall risk was affected when assuming the models are valid on an individual vehicle level. Speed data from two applications of speed measurements were used in the study: an evaluation of movable speed cameras and a national evaluation of new speed limits in Sweden. The results showed that when applied on individual vehicle speed level compared with aggregated level, there was essentially no difference between these for the Power model in the case of injury accidents. However, for fatalities the difference was greater, especially for roads with new cameras where those driving fastest reduced their speed the most. For the case with new speed limits, the individual approach estimated a somewhat smaller effect, reflecting that changes in the 15th percentile (P15) were somewhat larger than changes in P85 in this case. For the Exponential model there was also a clear, although small, difference between applying the model to mean speed changes and individual vehicle speed changes when speed cameras were used. This applied both for injury accidents and fatalities. There were also larger effects for the Exponential model than for the Power model, especially for injury accidents. In conclusion, applying the Power or Exponential model to individual vehicle speeds is an alternative that provides reasonable results in relation to the original Power and Exponential models, but more research is needed to clarify the shape of the individual risk curve. It is not surprising that the impact on severe traffic crashes was larger in situations where those driving fastest reduced their speed the most. Further investigations on use of the Power and/or the

  15. Effects of vehicle speed on flight initiation by Turkey vultures: implications for bird-vehicle collisions.

    PubMed

    DeVault, Travis L; Blackwell, Bradley F; Seamans, Thomas W; Lima, Steven L; Fernández-Juricic, Esteban

    2014-01-01

    The avoidance of motorized vehicles is a common challenge for birds in the modern world. Birds appear to rely on antipredator behaviors to avoid vehicles, but modern vehicles (automobiles and aircraft) are faster than natural predators. Thus, birds may be relatively ill-equipped, in terms of sensory capabilities and behaviors, to avoid vehicles. We examined the idea that birds may be unable to accurately assess particularly high speeds of approaching vehicles, which could contribute to miscalculations in avoidance behaviors and ultimately cause collisions. We baited turkey vultures (Cathartes aura) to roads with animal carcasses and measured flight initiation distance and effective time-to-collision in response to a truck driving directly towards vultures from a starting distance of 1.13 km and at one of three speeds: 30, 60, or 90 kph (no vultures were struck). Flight initiation distance of vultures increased by a factor of 1.85 as speed increased from 30 to 90 kph. However, for 90-kph approaches there was no clear trend in flight initiation distance across replicates: birds appeared equally likely to initiate escape behavior at 40 m as at 220 m. Time-to-collision decreased by a factor of 0.62 with approach speeds from 30 to 90 kph. Also, at 90 kph, four vehicle approaches (17%) resulted in near collisions with vultures (time-to-collision ≤ 1.7 s), compared to none during 60 kph approaches and one during 30 kph approaches (4%). Our findings suggest that antipredator behaviors in turkey vultures, particularly stimulus processing and response, might not be well tuned to vehicles approaching at speeds ≥ 90 kph. The possible inability of turkey vultures to react appropriately to high-speed vehicles could be common among birds, and might represent an important determinant of bird-vehicle collisions.

  16. Effects of Vehicle Speed on Flight Initiation by Turkey Vultures: Implications for Bird-Vehicle Collisions

    PubMed Central

    DeVault, Travis L.; Blackwell, Bradley F.; Seamans, Thomas W.; Lima, Steven L.; Fernández-Juricic, Esteban

    2014-01-01

    The avoidance of motorized vehicles is a common challenge for birds in the modern world. Birds appear to rely on antipredator behaviors to avoid vehicles, but modern vehicles (automobiles and aircraft) are faster than natural predators. Thus, birds may be relatively ill-equipped, in terms of sensory capabilities and behaviors, to avoid vehicles. We examined the idea that birds may be unable to accurately assess particularly high speeds of approaching vehicles, which could contribute to miscalculations in avoidance behaviors and ultimately cause collisions. We baited turkey vultures (Cathartes aura) to roads with animal carcasses and measured flight initiation distance and effective time-to-collision in response to a truck driving directly towards vultures from a starting distance of 1.13 km and at one of three speeds: 30, 60, or 90 kph (no vultures were struck). Flight initiation distance of vultures increased by a factor of 1.85 as speed increased from 30 to 90 kph. However, for 90-kph approaches there was no clear trend in flight initiation distance across replicates: birds appeared equally likely to initiate escape behavior at 40 m as at 220 m. Time-to-collision decreased by a factor of 0.62 with approach speeds from 30 to 90 kph. Also, at 90 kph, four vehicle approaches (17%) resulted in near collisions with vultures (time-to-collision ≤1.7 s), compared to none during 60 kph approaches and one during 30 kph approaches (4%). Our findings suggest that antipredator behaviors in turkey vultures, particularly stimulus processing and response, might not be well tuned to vehicles approaching at speeds ≥90 kph. The possible inability of turkey vultures to react appropriately to high-speed vehicles could be common among birds, and might represent an important determinant of bird-vehicle collisions. PMID:24503622

  17. Lunar Roving Vehicle gets speed workout by Astronaut John Young

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Lunar Roving Vehicle (LRV) gets a speed workout by Astronaut John W. Young in the 'Grand Prix' run during the third Apollo 16 extravehicular activity (EVA-3) at the Descartes landing site. This view is a frame from motion picture film exposed by a 16mm Maurer camera held by Astronaut Charels M. Duke Jr.

  18. Lunar Roving Vehicle gets speed workout by Astronaut John Young

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Lunar Roving Vehicle (LRV) gets a speed workout by Astronaut John W. Young in the 'Grand Prix' run during the third Apollo 16 extravehicular activity (EVA-3) at the Descartes landing site. Note the front wheels of the LRV are off the ground. This view is a frame from motion picture film exposed by a 16mm Maurer camera held by Astronaut Charles M. Duke Jr.

  19. The Effects of a Rectangular Rapid-Flashing Beacon on Vehicle Speed

    ERIC Educational Resources Information Center

    VanWagner, Michelle; Van Houten, Ron; Betts, Brian

    2011-01-01

    In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal…

  20. Analysis and control of high-speed wheeled vehicles

    NASA Astrophysics Data System (ADS)

    Velenis, Efstathios

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

  1. The preferred walk to run transition speed in actual lunar gravity.

    PubMed

    De Witt, John K; Edwards, W Brent; Scott-Pandorf, Melissa M; Norcross, Jason R; Gernhardt, Michael L

    2014-09-15

    Quantifying the preferred transition speed (PTS) from walking to running has provided insight into the underlying mechanics of locomotion. The dynamic similarity hypothesis suggests that the PTS should occur at the same Froude number across gravitational environments. In normal Earth gravity, the PTS occurs at a Froude number of 0.5 in adult humans, but previous reports found the PTS occurred at Froude numbers greater than 0.5 in simulated lunar gravity. Our purpose was to (1) determine the Froude number at the PTS in actual lunar gravity during parabolic flight and (2) compare it with the Froude number at the PTS in simulated lunar gravity during overhead suspension. We observed that Froude numbers at the PTS in actual lunar gravity (1.39±0.45) and simulated lunar gravity (1.11±0.26) were much greater than 0.5. Froude numbers at the PTS above 1.0 suggest that the use of the inverted pendulum model may not necessarily be valid in actual lunar gravity and that earlier findings in simulated reduced gravity are more accurate than previously thought.

  2. Maxillofacial injuries in moose-motor vehicle collisions versus other high-speed motor vehicle collisions

    PubMed Central

    Kim, Sharon; Harrop, A Robertson

    2005-01-01

    BACKGROUND: Anecdotal experience has suggested that there is a higher frequency of maxillofacial injuries among motor vehicle collisions involving moose. OBJECTIVES: A retrospective cohort study design was used to investigate the incidence of various injuries resulting from moose-motor vehicle collisions versus other high-speed motor vehicle collisions. METHODS: A chart review was conducted among patients presenting to a Canadian regional trauma centre during the five-year period from 1996 to 2000. RESULTS: Fifty-seven moose-motor vehicle collisions were identified; 121 high-speed collisions were randomly selected as a control group. Demographic, collision and injury data were collected from these charts and statistically analyzed. The general demographic features of the two groups were similar. Moose collisions were typically frontal impact resulting in windshield damage. The overall injury severity was similar in both groups. Likewise, the frequency of intracranial, spinal, thoracic and extremity injuries was similar for both groups. The group involved in collisions with moose, however, was 1.8 times more likely then controls to sustain a maxillofacial injury (P=0.004) and four times more likely to sustain a maxillofacial fracture (P=0.006). CONCLUSIONS: Occupants of motor vehicles colliding with moose are more likely to sustain maxillofacial injuries than those involved in other types of motor vehicle collisions. It is speculated that this distribution of injuries relates to the mechanism of collision with these large mammals with a high centre of gravity. PMID:24227930

  3. Braking hazards of golf cars and low speed vehicles.

    PubMed

    Seluga, K J; Ojalvo, I U

    2006-11-01

    Research and analysis of braking issues for golf cars and other low speed vehicles (LSVs) are reported in this study. It is shown that many such vehicles only provide braking for their rear wheels, which can lead to a driver losing control during travel on typical steep downgrades. The braking performance of a golf car equipped with brakes on two or four wheels was analyzed to determine the effects of two and four wheel brake designs on braking efficiency and vehicle yaw stability. Besides reducing braking efficiency, it is demonstrated that installing brakes on only the rear wheels can lead to directional instability (fishtailing) and rollover when the rear wheels are braked until skidding occurs. The nonexistence of golf course standards and the inadequacy of golf car and LSV standards are noted and a connection between this and the comparatively high level of accidents with such vehicles is inferred. Based on these results, it is advisable to install brakes on all four wheels of golf cars and LSVs. In addition, new safety standards should be considered to reduce the occurrence of golf car accidents on steep downhill slopes.

  4. Measurement of vehicles speed with full waveform lidar

    NASA Astrophysics Data System (ADS)

    Muzal, Michał; Mierczyk, Zygmunt; Zygmunt, Marek; Wojtanowski, Jacek; Piotrowski, Wiesław

    2016-12-01

    Measurement of vehicles speed by means of displacement measurement with "time of flight" lidar requires gathering of accurate information about distance to the vehicle in a set time interval. As with any pulsed laser lidar, its maximum range is limited by available incoming signal to noise ratio. That ratio determines not only maximum range, but also accuracy of measurement. For fast and precise measurements of speed of the vehicles their displacement should bee measured with centimeter accuracy. However that demand is hard to reach on long distances and poor quality of the echo signal. Improving accuracy beyond given by a single pulse probing requires emission of several probing pulses. Total displacement error will than fall with the square root of the number of executed measurements. Yet this method will not extend available distance beyond the limit set by threshold detection systems. Acquisition of the full waveform of received signals is a method that allows extension of maximum range through synchronic addition of subsequent waveforms. Doing so improves SNR by a well-known factor of square root of the number of carried additions. Disadvantage of this method is that it requires use of fast analog to digital converters for data acquisition, and simple distance calculation algorithms may not give the adequate accuracy due to relatively long sampling period of reasonable priced ADC's. In this article more advanced algorithms of distance calculations that base on ADC raw data are presented and analyzed. Practical implementation of algorithm in prototype design of laser speed gun is shown along with real life test results.

  5. THE EFFECTS OF A RECTANGULAR RAPID-FLASHING BEACON ON VEHICLE SPEED

    PubMed Central

    Van Wagner, Michelle; Van Houten, Ron; Betts, Brian

    2011-01-01

    In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal design. The percentage of vehicles traveling above 41 mph (66 km per hour) decreased by 20%, and speed distributions showed a shift toward lower speeds during the RRFB condition. PMID:21941395

  6. Influence of vehicle parameters on critical hunting speed based on Ruzicka model

    NASA Astrophysics Data System (ADS)

    Cui, Dabin; Li, Li; Jin, Xuesong; Xiao, Xinbiao; Ding, Junjun

    2012-05-01

    While introducing foreign advanced technology and cooperating with Chinese famous research institutes, the high-speed vehicles are designed and take the major task of passenger transport in China. In high-speed vehicle, the characteristic of shock absorber is an important parameter which determines overall behavior of the vehicle. The most existing researches neglect the influence of the series stiffness of the shock absorber on the vehicle dynamic behavior and have one-sided views on the equivalent conicity of wheel tread. In this paper, a high speed passenger vehicle in China is modeled to investigate the effect of the parameters taking series hydraulic shock absorber stiffness into consideration on Ruzicka model. Using the vehicle dynamic model, the effect of main suspension parameters on critical speed is studied. In order to verify the reasonableness of shock absorber parameter settings, vibration isolation characteristics are calculated and the relationship between suspension parameters and the vehicle critical hunting speed is studied. To study the influence of equivalent conicity on vehicle dynamic behavior, a series of wheel treads with different conicities are set and the vehicle critical hunting speeds with different wheel treads are calculated. The discipline between the equivalent conicity of wheel tread and critical speed are obtained in vehicle nonlinear system. The research results show that the critical speed of vehicle much depends on wheelset positioning stiffness and anti-hunting motion damper, and the series stiffness produces notable effect on the vehicle dynamic behavior. The critical speed has a peak value with the equivalent conicity increasing, which is different from the traditional opinion in which the critical speed will decrease with the conicity increasing. The relationship between critical speed and conicity of wheel tread is effected by the suspension parameters of the vehicle. The study results obtained offer a method and useful

  7. 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

  8. 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.

  9. Power-based Shift Schedule for Pure Electric Vehicle with a Two-speed Automatic Transmission

    NASA Astrophysics Data System (ADS)

    Wang, Jiaqi; Liu, Yanfang; Liu, Qiang; Xu, Xiangyang

    2016-11-01

    This paper introduces a comprehensive shift schedule for a two-speed automatic transmission of pure electric vehicle. Considering about driving ability and efficiency performance of electric vehicles, the power-based shift schedule is proposed with three principles. This comprehensive shift schedule regards the vehicle current speed and motor load power as input parameters to satisfy the vehicle driving power demand with lowest energy consumption. A simulation model has been established to verify the dynamic and economic performance of comprehensive shift schedule. Compared with traditional dynamic and economic shift schedules, simulation results indicate that the power-based shift schedule is superior to traditional shift schedules.

  10. 40 CFR 1037.640 - Variable vehicle speed limiters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... soft-top speed limit. You may also design your VSL to expire after accumulation of a predetermined number of miles. However, designs with soft tops or expiration features are subject to proration...) of this section. (ii) For VSLs with soft tops, the default speed does not include speeds...

  11. Impact characteristics of a vehicle population in low speed front to rear collisions.

    PubMed

    Nishimura, Naoya; Simms, Ciaran K; Wood, Denis P

    2015-06-01

    Rear impact collisions are mostly low severity, but carry a very high societal cost due to reported symptoms of whiplash and related soft tissue injuries. Given the difficulty in physiological measurement of damage in whiplash patients, there is a significant need to assess rear impact severity on the basis of vehicle damage. This paper presents fundamental impact equations on the basis of an equivalent single vehicle to rigid barrier collision in order to predict relationships between impact speed, maximum dynamic crush, mean and peak acceleration, time to common velocity and vehicle stiffness. These are then applied in regression analysis of published staged low speed rear impact tests. The equivalent mean and peak accelerations are linear functions of the collision closing speed, while the time to common velocity is independent of the collision closing speed. Furthermore, the time to common velocity can be used as a surrogate measure of the normalized vehicle stiffness, which provides opportunity for future accident reconstruction.

  12. Vehicle travel speeds and the incidence of fatal pedestrian crashes.

    PubMed

    Anderson, R W; McLean, A J; Farmer, M J; Lee, B H; Brooks, C G

    1997-09-01

    The aim of this study was to estimate the likely effect of reduced travel speeds on the incidence of pedestrian fatalities in Adelaide, Australia. The study was based on the results of detailed investigations of 176 fatal pedestrian crashes in the Adelaide area between 1983 and 1991. The method developed to estimate the effect of reduced travelling speed is described and supported by references to the published literature. A reduction in the speed limit from 60 to 50 km/h was one of four speed reduction scenarios considered. The smallest estimated reduction in fatal pedestrian collisions in the selection presented was 13%, for a scenario in which all drivers obeyed the existing speed limit. The largest estimated reduction was 48% for a scenario in which all drivers were travelling 10 km/h slower. The estimated reductions in fatalities obtained in this study are compared with those observed in places where the urban area speed limit has been lowered.

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

    PubMed

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

    2010-01-01

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

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

    PubMed Central

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

    2010-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Yoshida, Kinjiro; Egashira, Tatsuya; Hirai, Ryuichi

    1996-01-01

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

  16. Navigation and Hazard Avoidance for High-Speed Unmanned Ground Vehicles in Rough Terrain

    DTIC Science & Technology

    2008-07-07

    Potential Field Navigation of High Speed Vehicles on Rough Terrain,” Robotica , Vol. 25, No. 4, pp 409-424, July 2007 Udengaard, M., and Iagnemma, K...Navigation of Unmanned Ground Vehicles on Uneven Terrain using Potential Fields," to appear in Robotica , 2007 [16] Spenko, M., Kuroda, Y., Dubowsky, S

  17. Effects of weather conditions, light conditions, and road lighting on vehicle speed.

    PubMed

    Jägerbrand, Annika K; Sjöbergh, Jonas

    2016-01-01

    Light conditions are known to affect the number of vehicle accidents and fatalities but the relationship between light conditions and vehicle speed is not fully understood. This study examined whether vehicle speed on roads is higher in daylight and under road lighting than in darkness, and determined the combined effects of light conditions, posted speed limit and weather conditions on driving speed. The vehicle speed of passenger cars in different light conditions (daylight, twilight, darkness, artificial light) and different weather conditions (clear weather, rain, snow) was determined using traffic and weather data collected on an hourly basis for approximately 2 years (1 September 2012-31 May 2014) at 25 locations in Sweden (17 with road lighting and eight without). In total, the data included almost 60 million vehicle passes. The data were cleaned by removing June, July, and August, which have different traffic patterns than the rest of the year. Only data from the periods 10:00 A.M.-04:00 P.M. and 06:00 P.M.-10:00 P.M. were used, to remove traffic during rush hour and at night. Multivariate adaptive regression splines was used to evaluate the overall influence of independent variables on vehicle speed and nonparametric statistical testing was applied to test for speed differences between dark-daylight, dark-twilight, and twilight-daylight, on roads with and without road lighting. The results show that vehicle speed in general depends on several independent variables. Analyses of vehicle speed and speed differences between daylight, twilight and darkness, with and without road lighting, did not reveal any differences attributable to light conditions. However, vehicle speed decreased due to rain or snow and the decrease was higher on roads without road lighting than on roads with lighting. These results suggest that the strong association between traffic accidents and darkness or low light conditions could be explained by drivers failing to adjust their

  18. Status of hydrodynamic technology as related to model tests of high speed marine vehicles

    NASA Astrophysics Data System (ADS)

    Wilson, R. A.; Savitsky, D.; Stevens, M. J.; Balquet, R. J.; Muller-Graf, B.; Murakami, T.; Prokohorov, S. D.; Vanoossanen, P.

    1981-07-01

    The High Speed Marine Vehicle Panel of the 16th International Towing Tank Conference prepared hydrodynamic technology status reports related to model tank tests of SWATH, semidisplacement round bilge hulls, planing hulls, semisubmerged hydrofoils, surface effect ships, and air cushion vehicles. Each status report, plus the results of an initial survey of worldwide towing tanks conducting model experiments of high speed vessels, are contained herein. Hydrodynamic problems related to model testing and the full-scale extrapolation of the data for these vehicle types are also presented.

  19. Wind plant capacity credit variations: A comparison of results using multiyear actual and simulated wind-speed data

    SciTech Connect

    Milligan, M.R.

    1997-12-31

    Although it is widely recognized that variations in annual wind energy capture can be significant, it is not clear how significant this effect is on accurately calculating the capacity credit of a wind plant. An important question is raised concerning whether one year of wind data is representative of long-term patterns. This paper calculates the range of capacity credit measures based on 13 years of actual wind-speed data. The results are compared to those obtained with synthetic data sets that are based on one year of data. Although the use of synthetic data sets is a considerable improvement over single-estimate techniques, this paper finds that the actual inter-annual variation in capacity credit is still understated by the synthetic data technique.

  20. Development of an Evaluation System for Vertical Vibration of Railway Vehicles with Field-Portable Actuators (2nd Report, Excitation Tests of an Actual Commuter Vehicle)

    NASA Astrophysics Data System (ADS)

    Takigami, Tadao; Tomioka, Takahiro

    Bending vibration characteristics of railway vehicles have been investigated in general under excitation tests, in which a carbody was directly excited by a shaker. It is however very difficult with their results to evaluate the ride quality of passengers under conditions that the vehicle runs on a certain track. The authors are therefore developing an evaluation system for vertical vibration of railway vehicles. This system consists of an excitation system equipped with linear actuators, the elastic supporting device installed between wheels and rails, and analytical techniques to estimate the power spectral density (PSD) and the ride quality level (LT) which feature the ride quality. In this paper, we describe the excitation tests performed using an actual commuter car and the estimated PSD and LT are compared with what substantially measured under the running conditions.

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

    PubMed

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

    2016-02-19

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

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

    PubMed Central

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

    2016-01-01

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

  3. Aerodynamic braking of high speed ground transportation vehicles.

    NASA Technical Reports Server (NTRS)

    Marte, J. E.; Marko, W. J.

    1973-01-01

    The drag effectiveness of aerodynamic brakes arranged in series on a train-like vehicle was investigated. Fixed- and moving-model testing techniques were used in order to determine the importance of proper vehicle-ground interference simulation. Fixed-model tests were carried out on a sting-mounted model: alone; with a fixed ground plane; and in proximity to an image model. Moving-model tests were conducted in a vertical slide-wire facility with and without a ground plane. Results from investigations of one brake configuration are presented which show the effect of the number of brakes in the set and of spacing between brakes.

  4. Robust/optimal temperature profile control of a high-speed aerospace vehicle using neural networks.

    PubMed

    Yadav, Vivek; Padhi, Radhakant; Balakrishnan, S N

    2007-07-01

    An approximate dynamic programming (ADP)-based suboptimal neurocontroller to obtain desired temperature for a high-speed aerospace vehicle is synthesized in this paper. A 1-D distributed parameter model of a fin is developed from basic thermal physics principles. "Snapshot" solutions of the dynamics are generated with a simple dynamic inversion-based feedback controller. Empirical basis functions are designed using the "proper orthogonal decomposition" (POD) technique and the snapshot solutions. A low-order nonlinear lumped parameter system to characterize the infinite dimensional system is obtained by carrying out a Galerkin projection. An ADP-based neurocontroller with a dual heuristic programming (DHP) formulation is obtained with a single-network-adaptive-critic (SNAC) controller for this approximate nonlinear model. Actual control in the original domain is calculated with the same POD basis functions through a reverse mapping. Further contribution of this paper includes development of an online robust neurocontroller to account for unmodeled dynamics and parametric uncertainties inherent in such a complex dynamic system. A neural network (NN) weight update rule that guarantees boundedness of the weights and relaxes the need for persistence of excitation (PE) condition is presented. Simulation studies show that in a fairly extensive but compact domain, any desired temperature profile can be achieved starting from any initial temperature profile. Therefore, the ADP and NN-based controllers appear to have the potential to become controller synthesis tools for nonlinear distributed parameter systems.

  5. High Speed Lunar Navigation for Crewed and Remotely Piloted Vehicles

    NASA Technical Reports Server (NTRS)

    Pedersen, L.; Allan, M.; To, V.; Utz, H.; Wojcikiewicz, W.; Chautems, C.

    2010-01-01

    Increased navigation speed is desirable for lunar rovers, whether autonomous, crewed or remotely operated, but is hampered by the low gravity, high contrast lighting and rough terrain. We describe lidar based navigation system deployed on NASA's K10 autonomous rover and to increase the terrain hazard situational awareness of the Lunar Electric Rover crew.

  6. Predicting Light-Duty Vehicle Fuel Economy as a Function of Highway Speed

    SciTech Connect

    Thomas, John F; Hwang, Ho-Ling; West, Brian H; Huff, Shean P

    2013-01-01

    The www.fueleconomy.gov website offers information such as window label fuel economy for city, highway, and combined driving for all U.S.-legal light-duty vehicles from 1984 to the present. The site is jointly maintained by the U.S. Department of Energy and the U.S. Environmental Protection Agency (EPA), and also offers a considerable amount of consumer information and advice pertaining to vehicle fuel economy and energy related issues. Included with advice pertaining to driving styles and habits is information concerning the trend that as highway cruising speed is increased, fuel economy will degrade. An effort was undertaken to quantify this conventional wisdom through analysis of dynamometer testing results for 74 vehicles at steady state speeds from 50 to 80 mph. Using this experimental data, several simple models were developed to predict individual vehicle fuel economy and its rate of change over the 50-80 mph speed range interval. The models presented require a minimal number of vehicle attributes. The simplest model requires only the EPA window label highway mpg value (based on the EPA specified estimation method for 2008 and beyond). The most complex of these simple model uses vehicle coast-down test coefficients (from testing prescribed by SAE Standard J2263) known as the vehicle Target Coefficients, and the raw fuel economy result from the federal highway test. Statistical comparisons of these models and discussions of their expected usefulness and limitations are offered.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-03-11

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

  9. A novel car following model considering average speed of preceding vehicles group

    NASA Astrophysics Data System (ADS)

    Sun, Dihua; Kang, Yirong; Yang, Shuhong

    2015-10-01

    In this paper, a new car following model is presented by considering the average speed effect of preceding vehicles group in cyber-physical systems (CPS) environment. The effect of this new consideration upon the stability of traffic flow is examined through linear stability analysis. A modified Korteweg-de Vries (mKdV) equation was derived via nonlinear analysis to describe the propagating behavior of traffic density wave near the critical point. Good agreement between the simulation and the analytical results shows that average speed of preceding vehicles group leads to the stabilization of traffic systems, and thus can efficiently suppress the emergence of traffic jamming.

  10. Dynamic Analysis of Coupled Vehicle-Bridge System with Uniformly Variable Speed

    NASA Astrophysics Data System (ADS)

    Wei-zhen, Li; Chang-ping, Chen; Yi-qi, Mao; Chang-zhao, Qian

    2016-09-01

    In this paper, a planar biaxial vehicle model with four degrees of freedom is presented based on spring-damping-mass system theory. By using Runge-Kutta method, the dynamic characteristics of a simply support bridge acting by moving vehicle with uniform variable speed are analyzed, and the effects of inertia force, relative acceleration and initial velocity are taken into consideration in the present research. The time-deflection response curves of the bridge under the variation of initial speed and acceleration are analyzed. Some valuable results are found which can provide a theoretical direction for the consideration of dynamical characteristics in design of bridge system.

  11. Gear ratio optimization and shift control of 2-speed I-AMT in electric vehicle

    NASA Astrophysics Data System (ADS)

    Gao, Bingzhao; Liang, Qiong; Xiang, Yu; Guo, Lulu; Chen, Hong

    2015-01-01

    Connecting a 2-speed transmission with the drive motor improves the dynamic and economic performance of electric passenger vehicles. A novel 2-speed I-AMT (Inverse Automated Manual Transmission) is studied, and the dry clutch is located at the rear of the transmission so that the traction interruption of traditional AMT can be cancelled. After the gear ratios are optimized using Dynamic Programming, gear shift control is addressed, and smooth shift process without torque hole is achieved through feed-forward and feed-back control of the clutch and the motor. Finally the proposed electric vehicle (EV) is compared with an EV with fixed-ratio gear box, and it is shown that the 2-speed AMT with a rear-mounted dry clutch has much better performance in terms of acceleration time, maximum speed and energy economy. The effect of clutch friction loss during shifting on the energy efficiency of the whole driving range is analyzed as well.

  12. Effects of vehicle-pedestrian interaction and speed limit on traffic performance of intersections

    NASA Astrophysics Data System (ADS)

    Li, Xiang; Sun, Jian-Qiao

    2016-10-01

    The intersection model consisting of vehicle model, pedestrian model, pedestrian-vehicle interaction model and intersection rules has been presented in this paper. The well-established vehicle and pedestrian movement models in the literature are combined and applied to the intersection system with additional rules. Extensive numerical simulations with different scenarios are carried out. The effects of road speed limit, vehicle arrival rate, pedestrian regularity rate and vehicle rational rate on the intersection performance are quantitatively investigated. Three measures of the traffic performance are studied including transportation efficiency, energy economy and traffic safety. We have found that the energy economy can be achieved with the high transportation efficiency, and that the traffic safety is in conflict with the efficiency. Furthermore, we have found that the pedestrian interference makes the intersection performance worse, resulting in lower transportation efficiency, more energy consumptions and higher safety risk.

  13. Aerothermodynamics of expert ballistic vehicle at hypersonic speeds

    NASA Astrophysics Data System (ADS)

    Kharitonov, A. M.; Adamov, N. P.; Chirkashenko, V. F.; Mazhul, I. I.; Shpak, S. I.; Shiplyuk, A. N.; Vasenyov, L. G.; Zvegintsev, V. I.; Muylaert, J. M.

    2012-01-01

    The European EXPErimental Re-entry Test bed (EXPERT) vehicle is intended for studying various basic phenomena, such as the boundary-layer transition on blunted bodies, real gas effects during shock wave/boundary layer interaction, and effect of surface catalycity. Another task is to develop methods for recalculating the results of windtunnel experiments to flight conditions. The EXPERT program implies large-scale preflight research, in particular, various calculations with the use of advanced numerical methods, experimental studies of the models in various wind tunnels, and comparative analysis of data obtained for possible extrapolation of data to in-flight conditions. The experimental studies are performed in various aerodynamic centers of Europe and Russia under contracts with ESA-ESTEC. In particular, extensive experiments are performed at the Von Karman Institute for Fluid Dynamics (VKI, Belgium) and also at the DLR aerospace center in Germany. At ITAM SB RAS, the experimental studies of the EXPERT model characteristic were performed under ISTC Projects 2109, 3151, and 3550, in the T-313 supersonic wind tunnel and AT-303 hypersonic wind tunnel.

  14. The Effectiveness of School Signs with Flashing Beacons in Reducing Vehicle Speeds. Research Report No. 429.

    ERIC Educational Resources Information Center

    Zegeer, Charles V.

    A detailed study of warning signs with flashers in school zones was conducted by the Kentucky Department of Transportation to determine the signs' effectiveness in reducing the speeds of vehicles during times of pedestrian activity. Field investigations were conducted at all of the 120 flasher locations in Kentucky Highway Districts 6, 7, and 9.…

  15. 75 FR 25927 - Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-10

    ... Transportation Federal Railroad Administration 49 CFR Parts 213 and 238 Vehicle/Track Interaction Safety... Administration 49 CFR Parts 213 and 238 RIN 2130-AC09 Vehicle/Track Interaction Safety Standards; High-Speed and... Safety Standards and Passenger Equipment Safety Standards applicable to high-speed and high...

  16. Influences of aerodynamic loads on hunting stability of high-speed railway vehicles and parameter studies

    NASA Astrophysics Data System (ADS)

    Zeng, Xiao-Hui; Wu, Han; Lai, Jiang; Sheng, Hong-Zhi

    2014-12-01

    The influences of steady aerodynamic loads on hunting stability of high-speed railway vehicles were investigated in this study. A mechanism is suggested to explain the change of hunting behavior due to actions of aerodynamic loads: the aerodynamic loads can change the position of vehicle system (consequently the contact relations), the wheel/rail normal contact forces, the gravitational restoring forces/moments and the creep forces/moments. A mathematical model for hunting stability incorporating such influences was developed. A computer program capable of incorporating the effects of aerodynamic loads based on the model was written, and the critical speeds were calculated using this program. The dependences of linear and nonlinear critical speeds on suspension parameters considering aerodynamic loads were analyzed by using the orthogonal test method, the results were also compared with the situations without aerodynamic loads. It is shown that the most dominant factors affecting linear and nonlinear critical speeds are different whether the aerodynamic loads considered or not. The damping of yaw damper is the most dominant influencing factor for linear critical speeds, while the damping of lateral damper is most dominant for nonlinear ones. When the influences of aerodynamic loads are considered, the linear critical speeds decrease with the rise of crosswind velocity, whereas it is not the case for the nonlinear critical speeds. The variation trends of critical speeds with suspension parameters can be significantly changed by aerodynamic loads. Combined actions of aerodynamic loads and suspension parameters also affect the critical speeds. The effects of such joint action are more obvious for nonlinear critical speeds.

  17. Coupled vibration analysis of Maglev vehicle-guideway while standing still or moving at low speeds

    NASA Astrophysics Data System (ADS)

    Kim, Ki-Jung; Han, Jong-Boo; Han, Hyung-Suk; Yang, Seok-Jo

    2015-04-01

    Dynamic instability, that is, resonance, may occur on an electromagnetic suspension-type Maglev that runs over the elevated guideway, particularly at very low speeds, due to the flexibility of the guideway. An analysis of the dynamic interaction between the vehicle and guideway is required at the design stage to investigate such instability, setting slender guideway in design direction for reducing construction costs. In addition, it is essential to design an effective control algorithm to solve the problem of instability. In this article, a more detailed model for the dynamic interaction of vehicle/guideway is proposed. The proposed model incorporates a 3D full vehicle model based on virtual prototyping, flexible guideway by a modal superposition method and levitation electromagnets including feedback controller into an integrated model. By applying the proposed model to an urban Maglev vehicle newly developed for commercial application, an analysis of the instability phenomenon and an investigation of air gap control performance are carried out through a simulation.

  18. A Ground-Based Research Vehicle for Base Drag Studies at Subsonic Speeds

    NASA Technical Reports Server (NTRS)

    Diebler, Corey; Smith, Mark

    2002-01-01

    A ground research vehicle (GRV) has been developed to study the base drag on large-scale vehicles at subsonic speeds. Existing models suggest that base drag is dependent upon vehicle forebody drag, and for certain configurations, the total drag of a vehicle can be reduced by increasing its forebody drag. Although these models work well for small projectile shapes, studies have shown that they do not provide accurate predictions when applied to large-scale vehicles. Experiments are underway at the NASA Dryden Flight Research Center to collect data at Reynolds numbers to a maximum of 3 x 10(exp 7), and to formulate a new model for predicting the base drag of trucks, buses, motor homes, reentry vehicles, and other large-scale vehicles. Preliminary tests have shown errors as great as 70 percent compared to Hoerner's two-dimensional base drag prediction. This report describes the GRV and its capabilities, details the studies currently underway at NASA Dryden, and presents preliminary results of both the effort to formulate a new base drag model and the investigation into a method of reducing total drag by manipulating forebody drag.

  19. Modeling and nonlinear hunting stability analysis of high-speed railway vehicle moving on curved tracks

    NASA Astrophysics Data System (ADS)

    Cheng, Yung-Chang; Lee, Sen-Yung; Chen, Hsing-Hao

    2009-07-01

    A heuristic nonlinear creep model is used to derive the nonlinear coupled differential equations of motion of a high-speed railway vehicle traveling on a curved track. The vehicle dynamics are modeled using a 21 degree-of-freedom (21-DOF) system which takes account of the lateral displacement and yaw angle of each wheelset, the lateral displacement, vertical displacement, roll angle and yaw angle of the truck frames, and the lateral displacement, vertical displacement, roll angle, pitch angle and yaw angle of the car body. To analyze the respective effects of the major system parameters on the vehicle dynamics, the 21-DOF system is reduced to 20-DOF, 14-DOF and 6-DOF models, respectively, by excluding designated subsets of the system parameters. The validity of the analytical models and the numerical solution procedure is confirmed by comparing the result obtained using the 6-DOF model for the critical velocity of a railway vehicle traveling on a tangent track with the solution presented in the literature. In general, the results obtained in this study show that the critical hunting speed derived using the 6-DOF or 14-DOF model is generally higher than that evaluated using the 20-DOF model. In addition, the critical hunting speed evaluated via the heuristic nonlinear creep model is lower than that derived using a linear creep model.

  20. Improvement of speed control performance using PID type neurocontroller in an electric vehicle system

    SciTech Connect

    Matsumura, S.; Omatu, S.; Higasa, H.

    1994-12-31

    In order to develop an efficient driving system for electric vehicle (EV), a testing system using motors has been built to simulate the driving performance of EVs. In the testing system, the PID (Proportional Integral Derivative) controller is used to control rotating speed of motor when the EV drives. In this paper, in order to improve the performance of speed control, a neural network is applied to tuning parameters of PID controller. It is shown, through experiments that a neural network can reduce output error effectively while the PID controller parameters are being tuned online. 6 refs.

  1. Development of Permanent Magnet Reluctance Motor Suitable for Variable-Speed Drive for Electric Vehicle

    NASA Astrophysics Data System (ADS)

    Sakai, Kazuto; Takahashi, Norio; Shimomura, Eiji; Arata, Masanobu; Nakazawa, Yousuke; Tajima, Toshinobu

    Regarding environmental and energy issues, increasing importance has been placed on energy saving in various systems. To save energy, it would be desirable if the total efficiency of various types of equipment were increased.Recently, a hybrid electric vehicle (HEV) and an electric vehicle (EV) have been developed. The use of new technologies will eventually lead to the realization of the new- generation vehicle with high efficiency. One new technology is the variable-speed drive over a wide range of speeds. The motor driving systems of the EV or the HEV must operate in the variable-speed range of up to 1:5. This has created the need for a high-efficiency motor that is capable of operation over a wide speed range. In this paper, we describe the concept of a novel permanent magnet reluctance motor (PRM) and discuss its characteristics. We developed the PRM, which has the capability of operating over a wide speed range with high efficiency. The PRM has a rotor with a salient pole, which generates magnetic anisotropy. In addition, the permanent magnets embedded in the rotor core counter the q-axis flux by the armature reaction. Then, the power density and the power factor increase. The PRM produces reluctance torque and torque by permanent magnet (PM) flux. The reluctance torque is 1 to 2 times larger than the PM torque. When the PRM operates over a constant-power speed range, the field component of the current will be regulated to maintain a constant voltage. The output power of the developed PRM is 8 to 250kW. It is clarified that the PRM operates at a wide variable-speed range (1:5) with high efficiency (92-97%). It is concluded that the PRM has high performance over a wide constant-power speed range. In addition, the PRM is constructed using a small PM, so that we can solve the problem of cost. Thus, the PRM is a superior machine that is suited for variable-speed drive applications.

  2. A methodology for analysing lateral coupled behavior of high speed railway vehicles and structures

    NASA Astrophysics Data System (ADS)

    Antolín, P.; Goicolea, J. M.; Astiz, M. A.; Alonso, A.

    2010-06-01

    Continuous increment of the speed of high speed trains entails the increment of kinetic energy of the trains. The main goal of this article is to study the coupled lateral behavior of vehicle-structure systems for high speed trains. Non linear finite element methods are used for structures whereas multibody dynamics methods are employed for vehicles. Special attention must be paid when dealing with contact rolling constraints for coupling bridge decks and train wheels. The dynamic models must include mixed variables (displacements and creepages). Additionally special attention must be paid to the contact algorithms adequate to wheel-rail contact. The coupled vehicle-structure system is studied in a implicit dynamic framework. Due to the presence of very different systems (trains and bridges), different frequencies are involved in the problem leading to stiff systems. Regarding to contact methods, a main branch is studied in normal contact between train wheels and bridge decks: penalty method. According to tangential contact FastSim algorithm solves the tangential contact at each time step solving a differential equation involving relative displacements and creepage variables. Integration for computing the total forces in the contact ellipse domain is performed for each train wheel and each solver iteration. Coupling between trains and bridges requires a special treatment according to the kinetic constraints imposed in the wheel-rail pair and the load transmission. A numerical example is performed.

  3. Testing of Lightweight Fuel Cell Vehicles System at Low Speeds with Energy Efficiency Analysis

    NASA Astrophysics Data System (ADS)

    Mustaffa, Muhammad Rizuwan B.; Mohamed, Wan Ahmad Najmi B. Wan

    2013-12-01

    A fuel cell vehicle power train mini test bench was developed which consists of a 1 kW open cathode hydrogen fuel cell, electric motor, wheel, gearing system, DC/DC converter and vehicle control system (VCS). Energy efficiency identification and energy flow evaluation is a useful tool in identifying a detail performance of each component and sub-systems in a fuel cell vehicle system configuration. Three artificial traction loads was simulated at 30 kg, 40 kg and 50 kg force on a single wheel drive configuration. The wheel speed range reported here covers from idle to 16 km/h (low speed range) as a preliminary input in the research work frame. The test result shows that the system efficiency is 84.5 percent when the energy flow is considered from the fuel cell to the wheel and 279 watts of electrical power was produced by the fuel cell during that time. Dynamic system responses was also identified as the load increases beyond the motor traction capabilities where the losses at the converter and motor controller increased significantly as it tries to meet the motor traction power demands. This work is currently being further expanded within the work frame of developing a road-worthy fuel cell vehicle.

  4. Design and control of a novel two-speed Uninterrupted Mechanical Transmission for electric vehicles

    NASA Astrophysics Data System (ADS)

    Fang, Shengnan; Song, Jian; Song, Haijun; Tai, Yuzhuo; Li, Fei; Sinh Nguyen, Truong

    2016-06-01

    Conventional all-electric vehicles (EV) adopt single-speed transmission due to its low cost and simple construction. However, with the adoption of this type of driveline system, development of EV technology leads to the growing performance requirements of drive motor. Introducing a multi-speed or two-speed transmission to EV offers the possibility of efficiency improvement of the whole powertrain. This paper presents an innovative two-speed Uninterrupted Mechanical Transmission (UMT), which consists of an epicyclic gearing system, a centrifugal clutch and a brake band, allowing the seamless shifting between two gears. Besides, driver's intention is recognized by the control system which is based on fuzzy logic controller (FLC), utilizing the signals of vehicle velocity and accelerator pedal position. The novel UMT shows better dynamic and comfort performance in compare with the optimized AMT with the same gear ratios. Comparison between the control strategy with recognition of driver intention and the conventional two-parameter gear shifting strategy is presented. And the simulation and analysis of the middle layer of optimal gearshift control algorithm is detailed. The results indicate that the UMT adopting FLC and optimal control method provides a significant improvement of energy efficiency, dynamic performance and shifting comfort for EV.

  5. Powertrain dynamics and control of a two speed dual clutch transmission for electric vehicles

    NASA Astrophysics Data System (ADS)

    Walker, Paul; Zhu, Bo; Zhang, Nong

    2017-02-01

    The purpose of this paper is to demonstrate the application of torque based powertrain control for multi-speed power shifting capable electric vehicles. To do so simulation and experimental studies of the shift transient behaviour of dual clutch transmission equipped electric vehicle powertrains is undertaken. To that end a series of power-on and power-off shift control strategies are then developed for both up and down gear shifts, taking note of the friction load requirements to maintain positive driving load for power-on shifting. A mathematical model of an electric vehicle powertrain is developed including a DC equivalent circuit model for the electric machine and multi-body dynamic model of the powertrain system is then developed and integrated with a hydraulic clutch control system model. Integral control of the powertrain is then performed through simulations on the develop powertrain system model for each of the four shift cases. These simulation results are then replicated on a full scale powertrain test rig. To evaluate the performance of results shift duration and vehicle jerk are used as metrics to demonstrate that the presented strategies are effective for shift control in electric vehicles. Qualitative comparison of both theoretical and experimental results demonstrates reasonable agreement between simulated and experimental outcomes.

  6. Multi-point contact of the high-speed vehicle-turnout system dynamics

    NASA Astrophysics Data System (ADS)

    Ren, Zunsong

    2013-05-01

    The wheel-rail contact problems, such as the number, location and the track of contact patches, are very important for optimizing the spatial structure of the rails and lowering the vehicle-turnout system dynamics. However, the above problems are not well solved currently because of having the difficulties in how to determine the multi-contact, to preciously present the changeable profiles of the rails and to establish an accurate spatial turnout system dynamics model. Based on a high-speed vehicle-turnout coupled model in which the track is modeled as flexible with rails and sleepers represented by beams, the line tracing extreme point method is introduced to investigate the wheel-rail multiple contact conditions and the key sections of the blade rail, longer nose rail, shorter rail in the switch and nose rail area are discretized to represent the varying profiles of rails in the turnout. The dynamic interaction between the vehicle and turnout is simulated for cases of the vehicle divergently passing the turnout and the multi-point contact is obtained. The tracks of the contact patches on the top of the rails are presented and the wheel-rail impact forces are offered in comparison with the contact patches transference on the rails. The numerical simulation results indicate that the length of two-point contact occurrence of a worn wheel profile and rails is longer than that of the new wheel profile and rails; The two-point contact definitely occurs in the switch and crossing area. Generally, three-point contact doesn't occur for the new rail profile, which is testified by the wheel-rails interpolation distance and the first order derivative function of the tracing line extreme points. The presented research is not only helpful to optimize the structure of the turnout, but also useful to lower the dynamics of the high speed vehicle-turnout system.

  7. Reduced sensitivity to visual looming inflates the risk posed by speeding vehicles when children try to cross the road.

    PubMed

    Wann, John P; Poulter, Damian R; Purcell, Catherine

    2011-04-01

    Almost all locomotor animals respond to visual looming or to discrete changes in optical size. The need to detect and process looming remains critically important for humans in everyday life. Road traffic statistics confirm that children up to 15 years old are overrepresented in pedestrian casualties. We demonstrate that, for a given pedestrian crossing time, vehicles traveling faster loom less than slower vehicles, which creates a dangerous illusion in which faster vehicles may be perceived as not approaching. Our results from perceptual tests of looming thresholds show strong developmental trends in sensitivity, such that children may not be able to detect vehicles approaching at speeds in excess of 20 mph. This creates a risk of injudicious road crossing in urban settings when traffic speeds are higher than 20 mph. The risk is exacerbated because vehicles moving faster than this speed are more likely to result in pedestrian fatalities.

  8. Unmanned air vehicle flow separation control using dielectric barrier discharge plasma at high wind speed

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Huang, Yong; Wang, WanBo; Wang, XunNian; Li, HuaXing

    2014-06-01

    The present paper described an experimental investigation of separation control of an Unmanned Aerial Vehicle (UAV) at high wind speeds. The plasma actuator was based on Dielectric Barrier Discharge (DBD) and operated in a steady manner. The flow over a wing of UAV was performed with smoke flow visualization in the ϕ0.75 m low speed wind tunnel to reveal the flow structure over the wing so that the locations of plasma actuators could be optimized. A full model of the UAV was experimentally investigated in the ϕ3.2 m low speed wind tunnel using a six-component internal strain gauge balance. The effects of the key parameters, including the locations of the plasma actuators, the applied voltage amplitude and the operating frequency, were obtained. The whole test model was made of aluminium and acted as a cathode of the actuator. The results showed that the plasma acting on the surface of UAV could obviously suppress the boundary layer separation and reduce the model vibration at the high wind speeds. It was found that the maximum lift coefficient of the UAV was increased by 2.5% and the lift/drag ratio was increased by about 80% at the wind speed of 100 m/s. The control mechanism of the plasma actuator at the test configuration was also analyzed.

  9. 78 FR 29808 - Notice of Receipt of Petition for Decision That Nonconforming 2012 Lita GLE-6 Low-Speed Vehicles...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... with, or are capable of being altered to comply with, all applicable FMVSS based on destructive test... requirement must have its control system reprogrammed to ensure that the vehicle meets the maximum speed... requirement. Any vehicle that does not meet the requirement must have its control system reprogramed to...

  10. Risk Factors Associated with Injury and Mortality from Paediatric Low Speed Vehicle Incidents: A Systematic Review

    PubMed Central

    Paul Anthikkat, Anne; Page, Andrew; Barker, Ruth

    2013-01-01

    Objective. This study reviews modifiable risk factors associated with fatal and nonfatal injury from low-speed vehicle runover (LSVRO) incidents involving children aged 0–15 years. Data Sources. Electronic searches for child pedestrian and driveway injuries from the peer-reviewed literature and transport-related websites from 1955 to 2012. Study Selection. 41 studies met the study inclusion criteria. Data Extraction. A systematic narrative summary was conducted that included study design, methodology, risk factors, and other study variables. Results. The most commonly reported risk factors for LSVRO incidents included age under 5 years, male gender, and reversing vehicles. The majority of reported incidents involved residential driveways, but several studies identified other traffic and nontraffic locations. Low socioeconomic status and rental accommodation were also associated with LSVRO injury. Vehicles were most commonly driven by a family member, predominantly a parent. Conclusion. There are a number of modifiable vehicular, environmental, and behavioural factors associated with LSVRO injuries in young children that have been identified in the literature to date. Strategies relating to vehicle design (devices for increased rearward visibility and crash avoidance systems), housing design (physical separation of driveway and play areas), and behaviour (driver behaviour, supervision of young children) are discussed. PMID:23781251

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  12. Method of measuring speed of LOS for optics-electricity system of unmanned aerial vehicle

    NASA Astrophysics Data System (ADS)

    Li, Hong-guang; Ji, Ming; Zhao, Miyang; Zhang, Tingting; Jia, Tao

    2016-10-01

    In order to resolve issue of azimuth framework stability of optics-electricity system for unmanned aerial vehicle depressing, reason of azimuth platform stability depressing and noise caused by secant compensation was analyzed, which work in big pitching angle with tradition mode of measuring speed. Stabilization controlling method with big pitching angle is designed in which azimuth platform install azimuth and roll gyro which was apeaked mutual, and azimuth angle velocity of line of sight was calculated. In the end, simulate experiment validate that, azimuth platform stability controlling performance of two axes platform with big pitching angle was advanced, and influence of gyro noise on controlling performance was depressed.

  13. 78 FR 16051 - Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-13

    ... 238 Vehicle/Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations; Final.../Track Interaction Safety Standards; High-Speed and High Cant Deficiency Operations AGENCY: Federal... amending the Track Safety Standards and Passenger Equipment Safety Standards to promote the...

  14. Dielectric barrier discharge actuator for vehicle drag reduction at highway speeds

    NASA Astrophysics Data System (ADS)

    Roy, Subrata; Zhao, Pengfei; DasGupta, Arnob; Soni, Jignesh

    2016-02-01

    We propose and demonstrate reduction of aerodynamic drag for a realistic geometry at highway speeds using serpentine dielectric barrier discharge actuators. A comparable linear plasma actuator fails to reduce the drag at these speeds. Experimental data collected for linear and serpentine plasma actuators under quiescent operating conditions show that the serpentine design has profound effect on near wall flow structure and resulting drag. For certain actuator arrangement, the measured drag reduced by over 14% at 26.8 m/s (60 mph) and over 10% at 31.3 m/s (70 mph) opening up realistic possibility of reasonable energy savings for full scale ground vehicles. In addition, the power consumption data and drag reduction effectiveness for different input signals are also presented.

  15. Orbit transfer vehicle engine technology program. Task B-6 high speed turbopump bearings

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Bearing types were evaluated for use on the Orbit Transfer Vehicle (OTV) high pressure fuel pump. The high speed, high load, and long bearing life requirements dictated selection of hydrostatic bearings as the logical candidate for this engine. Design and fabrication of a bearing tester to evaluate these cryogenic hydrostatic bearings was then conducted. Detailed analysis, evaluation of bearing materials, and design of the hydrostatic bearings were completed resulting in fabrication of Carbon P5N and Kentanium hydrostatic bearings. Rotordynamic analyses determined the exact bearing geometry chosen. Instrumentation was evaluated and data acquisition methods were determined for monitoring shaft motion up to speeds in excess of 200,000 RPM in a cryogenic atmosphere. Fabrication of all hardware was completed, but assembly and testing was conducted outside of this contract.

  16. Analysis and Test Correlation of Proof of Concept Box for Blended Wing Body-Low Speed Vehicle

    NASA Technical Reports Server (NTRS)

    Spellman, Regina L.

    2003-01-01

    The Low Speed Vehicle (LSV) is a 14.2% scale remotely piloted vehicle of the revolutionary Blended Wing Body concept. The design of the LSV includes an all composite airframe. Due to internal manufacturing capability restrictions, room temperature layups were necessary. An extensive materials testing and manufacturing process development effort was underwent to establish a process that would achieve the high modulus/low weight properties required to meet the design requirements. The analysis process involved a loads development effort that incorporated aero loads to determine internal forces that could be applied to a traditional FEM of the vehicle and to conduct detailed component analyses. A new tool, Hypersizer, was added to the design process to address various composite failure modes and to optimize the skin panel thickness of the upper and lower skins for the vehicle. The analysis required an iterative approach as material properties were continually changing. As a part of the material characterization effort, test articles, including a proof of concept wing box and a full-scale wing, were fabricated. The proof of concept box was fabricated based on very preliminary material studies and tested in bending, torsion, and shear. The box was then tested to failure under shear. The proof of concept box was also analyzed using Nastran and Hypersizer. The results of both analyses were scaled to determine the predicted failure load. The test results were compared to both the Nastran and Hypersizer analytical predictions. The actual failure occurred at 899 lbs. The failure was predicted at 1167 lbs based on the Nastran analysis. The Hypersizer analysis predicted a lower failure load of 960 lbs. The Nastran analysis alone was not sufficient to predict the failure load because it does not identify local composite failure modes. This analysis has traditionally been done using closed form solutions. Although Hypersizer is typically used as an optimizer for the design

  17. Numerical analysis of flow induced noise propagation in supercavitating vehicles at subsonic speeds.

    PubMed

    Ramesh, Sai Sudha; Lim, Kian Meng; Zheng, Jianguo; Khoo, Boo Cheong

    2014-04-01

    Flow supercavitation begins when fluid is accelerated over a sharp edge, usually at the nose of an underwater vehicle, where phase change occurs and causes low density gaseous cavity to gradually envelop the whole object (supercavity) and thereby enabling higher speeds of underwater vehicles. The process of supercavity inception/development by means of "natural cavitation" and its sustainment through ventilated cavitation result in turbulence and fluctuations at the water-vapor interface that manifest themselves as major sources of hydrodynamic noise. Therefore in the present context, three main sources are investigated, namely, (1) flow generated noise due to turbulent pressure fluctuations around the supercavity, (2) small scale pressure fluctuations at the vapor-water interface, and (3) pressure fluctuations due to direct impingement of ventilated gas-jets on the supercavity wall. An understanding of their relative contributions toward self-noise is very crucial for the efficient operation of high frequency acoustic sensors that facilitate the vehicle's guidance system. Qualitative comparisons of acoustic pressure distribution resulting from aforementioned sound sources are presented by employing a recently developed boundary integral method. By using flow data from a specially developed unsteady computational fluid dynamics solver for simulating supercavitating flows, the boundary-element method based acoustic solver was developed for computing flow generated sound.

  18. Real Time Speed Estimation of Moving Vehicles from Side View Images from an Uncalibrated Video Camera

    PubMed Central

    Doğan, Sedat; Temiz, Mahir Serhan; Külür, Sıtkı

    2010-01-01

    In order to estimate the speed of a moving vehicle with side view camera images, velocity vectors of a sufficient number of reference points identified on the vehicle must be found using frame images. This procedure involves two main steps. In the first step, a sufficient number of points from the vehicle is selected, and these points must be accurately tracked on at least two successive video frames. In the second step, by using the displacement vectors of the tracked points and passed time, the velocity vectors of those points are computed. Computed velocity vectors are defined in the video image coordinate system and displacement vectors are measured by the means of pixel units. Then the magnitudes of the computed vectors in image space should be transformed to the object space to find the absolute values of these magnitudes. This transformation requires an image to object space information in a mathematical sense that is achieved by means of the calibration and orientation parameters of the video frame images. This paper presents proposed solutions for the problems of using side view camera images mentioned here. PMID:22399909

  19. Estimation of longitudinal speed robust to road conditions for ground vehicles

    NASA Astrophysics Data System (ADS)

    Hashemi, Ehsan; Kasaiezadeh, Alireza; Khosravani, Saeid; Khajepour, Amir; Moshchuk, Nikolai; Chen, Shih-Ken

    2016-08-01

    This article seeks to develop a longitudinal vehicle velocity estimator robust to road conditions by employing a tyre model at each corner. Combining the lumped LuGre tyre model and the vehicle kinematics, the tyres internal deflection state is used to gain an accurate estimation. Conventional kinematic-based velocity estimators use acceleration measurements, without correction with the tyre forces. However, this results in inaccurate velocity estimation because of sensor uncertainties which should be handled with another measurement such as tyre forces that depend on unknown road friction. The new Kalman-based observer in this paper addresses this issue by considering tyre nonlinearities with a minimum number of required tyre parameters and the road condition as uncertainty. Longitudinal forces obtained by the unscented Kalman filter on the wheel dynamics is employed as an observation for the Kalman-based velocity estimator at each corner. The stability of the proposed time-varying estimator is investigated and its performance is examined experimentally in several tests and on different road surface frictions. Road experiments and simulation results show the accuracy and robustness of the proposed approach in estimating longitudinal speed for ground vehicles.

  20. An Airbreathing Launch Vehicle Design with Turbine-Based Low-Speed Propulsion and Dual Mode Scramjet High-Speed Propulsion

    NASA Technical Reports Server (NTRS)

    Moses, P. L.; Bouchard, K. A.; Vause, R. F.; Pinckney, S. Z.; Ferlemann, S. M.; Leonard, C. P.; Taylor, L. W., III; Robinson, J. S.; Martin, J. G.; Petley, D. H.

    1999-01-01

    Airbreathing launch vehicles continue to be a subject of great interest in the space access community. In particular, horizontal takeoff and horizontal landing vehicles are attractive with their airplane-like benefits and flexibility for future space launch requirements. The most promising of these concepts involve airframe integrated propulsion systems, in which the external undersurface of the vehicle forms part of the propulsion flowpath. Combining of airframe and engine functions in this manner involves all of the design disciplines interacting at once. Design and optimization of these configurations is a most difficult activity, requiring a multi-discipline process to analytically resolve the numerous interactions among the design variables. This paper describes the design and optimization of one configuration in this vehicle class, a lifting body with turbine-based low-speed propulsion. The integration of propulsion and airframe, both from an aero-propulsive and mechanical perspective are addressed. This paper primarily focuses on the design details of the preferred configuration and the analyses performed to assess its performance. The integration of both low-speed and high-speed propulsion is covered. Structural and mechanical designs are described along with materials and technologies used. Propellant and systems packaging are shown and the mission-sized vehicle weights are disclosed.

  1. Influence of road markings, lane widths and driver behaviour on proximity and speed of vehicles overtaking cyclists.

    PubMed

    Shackel, Stella C; Parkin, John

    2014-12-01

    The proximity and speed of motor traffic passing cyclists in non-separated conditions may be so close and so great as to cause discomfort. A variety of road design and driver behaviour factors may affect overtaking speeds and distances. The investigation presented in this paper builds on previous research and fills gaps in that research by considering the presence of cycle lanes on 20 mph and 30 mph roads, different lane widths, different lane markings, vehicle type, vehicle platooning and oncoming traffic. Data were collected from a bicycle ridden a distance of one metre from the kerb fitted with an ultrasonic distance detector and forward and sideways facing cameras. Reduced overtaking speeds correlate with narrower lanes, lower speed limits, and the absence of centre-line markings. Drivers passed slower if driving a long vehicle, driving in a platoon, and when approaching vehicles in the opposing carriageway were within five seconds of the passing point. Increased passing distances were found where there were wider or dual lane roads, and in situations where oncoming vehicles were further away and not in a platoon. In mixed traffic conditions, cyclists will be better accommodated by wider cross-sections, lower speed limits and the removal of the centre-line marking.

  2. 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.

  3. Car ADR/EDR recorders - uncertainty of vehicle's speed and trajectory determination

    NASA Astrophysics Data System (ADS)

    Guzek, Marek

    2010-01-01

    One of the basic tasks of the accident reconstruction is to define values of parameters of participants of the accident before its actual occurrence. The assessment of correct behaviours is made and the court decides whether the accident participants are guilty or innocent. Therefore, the credibility of specific values is essential. The use of socalled accident recorders - EDR/ADR type of devices, as an alternative compared to classical methods for accidents reconstruction - has become more common over the past years. The paper includes basic notions related to his type of devices, describes potential sources of uncertainty of the car motion reconstruction results obtained on the basis of their records. The examples presented confirm their usefulness, however, they also indicate possible significant errors in the motion parameters assessment if simplified devices are used (where vehicle body lean movements in motion are not analysed).

  4. Simultaneous measurements of on-road/in-vehicle nanoparticles and NOx while driving: Actual situations, passenger exposure and secondary formations.

    PubMed

    Yamada, Hiroyuki; Hayashi, Rumiko; Tonokura, Kenichi

    2016-09-01

    Simultaneous measurements of on-road and in-vehicle NO and NO2 levels, particle number concentrations (PNCs), and particles size distributions were performed while driving using a test vehicle equipped with real-time sensors. The results obtained on regional roads showed that heavy-duty vehicles in traffic seem to have a major impact on on-road air quality. Measurements on highways that included a 10km tunnel and a 2km uphill section of road indicated that sub-50nm particles have different features from the other species because of their higher volatility. The other species showed quite high on-road concentrations in the tunnel. In-vehicle conditions were made similar to the on-road ones by setting the air conditioning (AC) mode to the fresh air mode. The in-vehicle NO2 concentration in the tunnel was over 0.50ppmV, which is almost five times higher than the 1-hour ambient air quality standard proposed by the World Health Organization (WHO). In sections other than the tunnel, the in-vehicle NO2 concentration was almost the same as the 1-hour WHO standard. Higher on-road NO2/NOx ratios than those of exhaust gases and different behavior of sub-50nm particles from other species suggested that NO2 and sub-50nm particles were mainly due to secondary products formed by atmospheric reactions.

  5. Effects of parallelogram-shaped pavement markings on vehicle speed and safety of pedestrian crosswalks on urban roads in China.

    PubMed

    Guo, Yanyong; Liu, Pan; Liang, Qiyu; Wang, Wei

    2016-10-01

    The primary objective of this study was to evaluate the effects of parallelogram-shaped pavement markings on vehicle speed and crashes in the vicinity of urban pedestrian crosswalks. The research team measured speed data at twelve sites, and crash data at eleven sites. Observational cross-sectional studies were conducted to identify if the effects of parallelogram-shaped pavement markings on vehicle speeds and speed violations were statistically significant. The results showed that parallelogram-shaped pavement markings significantly reduced vehicle speeds and speed violations in the vicinity of pedestrian crosswalks. More specifically, the speed reduction effects varied from 1.89km/h to 4.41km/h with an average of 3.79km/h. The reduction in the 85th percentile speed varied from 0.81km/h to 5.34km/h with an average of 4.19km/h. Odds ratios (OR) showed that the parallelogram-shaped pavement markings had effects of a 7.1% reduction in the mean speed and a 6.9% reduction in the 85th percentile speed at the pedestrian crosswalks. The reduction of proportion of drivers exceeding the speed limit varied from 8.64% to 14.15% with an average of 11.03%. The results of the crash data analysis suggested that the use of parallelogram-shaped pavement markings reduced both the frequency and severity of crashes at pedestrian crosswalks. The parallelogram-shaped pavement markings had a significant effect on reducing the vehicle-pedestrian crashes. Two crash prediction models were developed for vehicle-pedestrian crashes and rear-end crashes. According to the crash models, the presence of parallelogram-shaped pavement markings reduced vehicle-pedestrian crashes at pedestrian crosswalks by 24.87% with a 95% confidence interval of [10.06-30.78%]. However, the model results also showed that the presence of parallelogram-shaped pavement markings increased rear-end crashes at pedestrian crosswalks by 5.4% with a 95% confidence interval of [0-11.2%].

  6. Effect Of Platooning on Fuel Consumption of Class 8 Vehicles Over a Range of Speeds, Following Distances, and Mass

    SciTech Connect

    Lammert, M. P.; Duran, A.; Diez, J.; Burton, K.; Nicholson, A.

    2014-10-01

    This research project evaluates fuel consumption results of two Class 8 tractor-trailer combinations platooned together compared to their standalone fuel consumption. A series of ten modified SAE Type II J1321 fuel consumption track tests were performed to document fuel consumption of two platooned vehicles and a control vehicle at varying steady-state speeds, following distances, and gross vehicle weights (GVWs). The steady-state speeds ranged from 55 mph to 70 mph, the following distances ranged from a 20-ft following distance to a 75-ft following distance, and the GVWs were 65K lbs and 80K lbs. All tractors involved had U.S. Environmental Protection Agency (EPA) SmartWay-compliant aerodynamics packages installed, and the trailers were equipped with side skirts. Effects of vehicle speed, following distance, and GVW on fuel consumption were observed and analyzed. The platooning demonstration system used in this study consisted of radar systems, Dedicated Short-Range Communication (DSRC) vehicle-to-vehicle (V2V) communications, vehicle braking and torque control interface, cameras and driver displays. The lead tractor consistently demonstrated an improvement in average fuel consumption reduction as following distance decreased, with results showing 2.7% to 5.3% fuel savings at a GVW of 65k. The trailing vehicle achieved fuel consumption savings ranging from 2.8% to 9.7%; tests during which the engine cooling fan did not operate achieved savings of 8.4% to 9.7%. 'Team' fuel savings, considering the platooned vehicles as one, ranged from 3.7% to 6.4%, with the best combined result being for 55 mph, 30-ft following distance, and 65k GVW.

  7. Appending High-Resolution Elevation Data to GPS Speed Traces for Vehicle Energy Modeling and Simulation

    SciTech Connect

    Wood, E.; Burton, E.; Duran, A.; Gonder, J.

    2014-06-01

    Accurate and reliable global positioning system (GPS)-based vehicle use data are highly valuable for many transportation, analysis, and automotive considerations. Model-based design, real-world fuel economy analysis, and the growing field of autonomous and connected technologies (including predictive powertrain control and self-driving cars) all have a vested interest in high-fidelity estimation of powertrain loads and vehicle usage profiles. Unfortunately, road grade can be a difficult property to extract from GPS data with consistency. In this report, we present a methodology for appending high-resolution elevation data to GPS speed traces via a static digital elevation model. Anomalous data points in the digital elevation model are addressed during a filtration/smoothing routine, resulting in an elevation profile that can be used to calculate road grade. This process is evaluated against a large, commercially available height/slope dataset from the Navteq/Nokia/HERE Advanced Driver Assistance Systems product. Results will show good agreement with the Advanced Driver Assistance Systems data in the ability to estimate road grade between any two consecutive points in the contiguous United States.

  8. Analysis and design of a speed and position system for maglev vehicles.

    PubMed

    Dai, Chunhui; Dou, Fengshan; Song, Xianglei; Long, Zhiqiang

    2012-01-01

    This paper mainly researches one method of speed and location detection for maglev vehicles. As the maglev train doesn't have any physical contact with the rails, it has to use non-contact measuring methods. The technology based on the inductive loop-cable could fulfill the requirement by using an on-board antenna which could detect the alternating magnetic field produced by the loop-cable on rails. This paper introduces the structure of a speed and position system, and analyses the electromagnetic field produced by the loop-cable. The equivalent model of the loop-cable is given and the most suitable component of the magnetic flux density is selected. Then the paper also compares the alternating current (AC) resistance and the quality factor between two kinds of coils which the antenna is composed of. The effect of the rails to the signal receiving is also researched and then the structure of the coils is improved. Finally, considering the common-mode interference, 8-word coils are designed and analyzed.

  9. Consideration of nonlinear wheel-rail contact forces for dynamic vehicle-bridge interaction in high-speed railways

    NASA Astrophysics Data System (ADS)

    Antolín, Pablo; Zhang, Nan; Goicolea, José M.; Xia, He; Astiz, Miguel Á.; Oliva, Javier

    2013-03-01

    In this work models with nonlinear wheel-rail contact forces are considered for analysing the dynamic interaction between high speed trains and bridges, in order to study dynamic effects both in the bridge and in the vehicles resulting from the coupling. Nonlinear contact models may be necessary for evaluating the stability and the safety of running traffic in situations such as vehicle overturn when the train is crossing a bridge under strong lateral winds or when an earthquake occurs. For studying the coupled dynamic response of trains and bridges, models of multibody dynamics are used for vehicles and the finite element method for structures. Special relevance is given here to the consideration of contact interaction forces between railway vehicles and the track. Four different interaction models are compared in this work: (1) a model where the vehicle wheelset is considered to be rigidly coupled to the track; (2) a staggered uncoupled method in which vehicle and structure are analysed separately; (3) a linear contact model in which lateral relative displacements between rails and train wheels are allowed, assuming biconic wheel and rail profiles and linear Kalker theory for tangential contact; (4) a nonlinear model in which realistic wheel and rail profiles, Hertz's nonlinear theory for normal contact and Kalker's nonlinear theory for tangential contact are used. The different models are applied and compared to experimental measurements for a test case of a high-speed train in China.

  10. Modelling road dust emission abatement measures using the NORTRIP model: Vehicle speed and studded tyre reduction

    NASA Astrophysics Data System (ADS)

    Norman, M.; Sundvor, I.; Denby, B. R.; Johansson, C.; Gustafsson, M.; Blomqvist, G.; Janhäll, S.

    2016-06-01

    Road dust emissions in Nordic countries still remain a significant contributor to PM10 concentrations mainly due to the use of studded tyres. A number of measures have been introduced in these countries in order to reduce road dust emissions. These include speed reductions, reductions in studded tyre use, dust binding and road cleaning. Implementation of such measures can be costly and some confidence in the impact of the measures is required to weigh the costs against the benefits. Modelling tools are thus required that can predict the impact of these measures. In this paper the NORTRIP road dust emission model is used to simulate real world abatement measures that have been carried out in Oslo and Stockholm. In Oslo both vehicle speed and studded tyre share reductions occurred over a period from 2004 to 2006 on a major arterial road, RV4. In Stockholm a studded tyre ban on Hornsgatan in 2010 saw a significant reduction in studded tyre share together with a reduction in traffic volume. The model is found to correctly simulate the impact of these measures on the PM10 concentrations when compared to available kerbside measurement data. Importantly meteorology can have a significant impact on the concentrations through both surface and dispersion conditions. The first year after the implementation of the speed reduction on RV4 was much drier than the previous year, resulting in higher mean concentrations than expected. The following year was much wetter with significant rain and snow fall leading to wet or frozen road surfaces for 83% of the four month study period. This significantly reduced the net PM10 concentrations, by 58%, compared to the expected values if meteorological conditions had been similar to the previous years. In the years following the studded tyre ban on Hornsgatan road wear production through studded tyres decreased by 72%, due to a combination of reduced traffic volume and reduced studded tyre share. However, after accounting for exhaust

  11. T-S fuzzy model predictive speed control of electrical vehicles.

    PubMed

    Khooban, Mohammad Hassan; Vafamand, Navid; Niknam, Taher

    2016-09-01

    This paper proposes a novel nonlinear model predictive controller (MPC) in terms of linear matrix inequalities (LMIs). The proposed MPC is based on Takagi-Sugeno (TS) fuzzy model, a non-parallel distributed compensation (non-PDC) fuzzy controller and a non-quadratic Lyapunov function (NQLF). Utilizing the non-PDC controller together with the Lyapunov theorem guarantees the stabilization issue of this MPC. In this approach, at each sampling time a quadratic cost function with an infinite prediction and control horizon is minimized such that constraints on the control input Euclidean norm are satisfied. To show the merits of the proposed approach, a nonlinear electric vehicle (EV) system with parameter uncertainty is considered as a case study. Indeed, the main goal of this study is to force the speed of EV to track a desired value. The experimental data, a new European driving cycle (NEDC), is used in order to examine the performance of the proposed controller. First, the equivalent TS model of the original nonlinear system is derived. After that, in order to evaluate the proficiency of the proposed controller, the achieved results of the proposed approach are compared with those of the conventional MPC controller and the optimal Fuzzy PI controller (OFPI), which are the latest research on the problem in hand.

  12. Experimental studies on boundary-layer transition on a reentry vehicle at transonic and supersonic speeds

    NASA Astrophysics Data System (ADS)

    Suzuki, Kojiro; Abe, Takashi

    1995-03-01

    The boundary-layer transition on the EXPRESS reentry capsule at transonic and supersonic speeds is studied experimentally by the wind tunnel tests. For the diagnostic of the turbulent transition of the boundary layer, the China-clay method is used. The experimental results clarify that when the freestream Mach number increases, the transition point moves downstream on the body surface and the distance between the beginning of the transition and its completion to the fully turbulent flow becomes larger. The effects of the freestream Mach number on the location of the boundary-layer transition are described successfully in terms of two nondimensional quantities, that is, the transition Reynolds number and the local Mach number at the boundary-layer edge. The oil-flow pictures reveal that in the transonic regime, the separation bubble is formed at the junction between the blunt nose and the conical part of the body and therefore the transition begins behind the reattachment point of the separation bubble. The effects of the turbulent transition on the aerodynamic characteristics of the reentry body are investigated by using the technique of the boundary-layer trip and the experimental results show that the aerodynamic characteristics of the EXPRESS reentry vehicle are not sensitive to the boundary-layer transition.

  13. Research on Streamlines and Aerodynamic Heating for Unstructured Grids on High-Speed Vehicles

    NASA Technical Reports Server (NTRS)

    DeJarnette, Fred R.; Hamilton, H. Harris (Technical Monitor)

    2001-01-01

    Engineering codes are needed which can calculate convective heating rates accurately and expeditiously on the surfaces of high-speed vehicles. One code which has proven to meet these needs is the Langley Approximate Three-Dimensional Convective Heating (LATCH) code. It uses the axisymmetric analogue in an integral boundary-layer method to calculate laminar and turbulent heating rates along inviscid surface streamlines. It requires the solution of the inviscid flow field to provide the surface properties needed to calculate the streamlines and streamline metrics. The LATCH code has been used with inviscid codes which calculated the flow field on structured grids, Several more recent inviscid codes calculate flow field properties on unstructured grids. The present research develops a method to calculate inviscid surface streamlines, the streamline metrics, and heating rates using the properties calculated from inviscid flow fields on unstructured grids. Mr. Chris Riley, prior to his departure from NASA LaRC, developed a preliminary code in the C language, called "UNLATCH", to accomplish these goals. No publication was made on his research. The present research extends and improves on the code developed by Riley. Particular attention is devoted to the stagnation region, and the method is intended for programming in the FORTRAN 90 language.

  14. Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system

    SciTech Connect

    Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

    1989-04-01

    This study was undertaken to (1) evaluate the potential contribution of high-temperature superconductors (HTSCs) to the technical and economic feasibility of magnetically levitated (maglev) vehicles, (2) determine the status of maglev transportation research in the United States and abroad, (3) identify the likelihood of a significant transportation market for high-speed maglev vehicles, and (4) provide a preliminary assessment of the potential energy and economic benefits of maglev systems. HTSCs should be considered as an enhancing, rather than an enabling, development for maglev transportation because they should improve reliability and reduce energy and maintenance costs. Superconducting maglev transportation technologies were developed in the United States in the late 1960s and early 1970s. Federal support was withdrawn in 1975, but major maglev transportation programs were continued in Japan and West Germany, where full-scale prototypes now carry passengers at speeds of 250 mi/h in demonstration runs. Maglev systems are generally viewed as very-high-speed train systems, but this study shows that the potential market for maglev technology as a train system, e.g., from one downtown to another, is limited. Rather, aircraft and maglev vehicles should be seen as complementing rather than competing transportation systems. If maglev systems were integrated into major hub airport operations, they could become economical in many relatively high-density US corridors. Air traffic congestion and associated noise and pollutant emissions around airports would also be reduced. 68 refs., 26 figs., 16 tabs.

  15. Optimal Predictive Control for Path Following of a Full Drive-by-Wire Vehicle at Varying Speeds

    NASA Astrophysics Data System (ADS)

    SONG, Pan; GAO, Bolin; XIE, Shugang; FANG, Rui

    2017-03-01

    The current research of the global chassis control problem for the full drive-by-wire vehicle focuses on the control allocation (CA) of the four-wheel-distributed traction/braking/steering systems. However, the path following performance and the handling stability of the vehicle can be enhanced a step further by automatically adjusting the vehicle speed to the optimal value. The optimal solution for the combined longitudinal and lateral motion control (MC) problem is given. First, a new variable step-size spatial transformation method is proposed and utilized in the prediction model to derive the dynamics of the vehicle with respect to the road, such that the tracking errors can be explicitly obtained over the prediction horizon at varying speeds. Second, a nonlinear model predictive control (NMPC) algorithm is introduced to handle the nonlinear coupling between any two directions of the vehicular planar motion and computes the sequence of the optimal motion states for following the desired path. Third, a hierarchical control structure is proposed to separate the motion controller into a NMPC based path planner and a terminal sliding mode control (TSMC) based path follower. As revealed through off-line simulations, the hierarchical methodology brings nearly 1700% improvement in computational efficiency without loss of control performance. Finally, the control algorithm is verified through a hardware in-the-loop simulation system. Double-lane-change (DLC) test results show that by using the optimal predictive controller, the root-mean-square (RMS) values of the lateral deviations and the orientation errors can be reduced by 41% and 30%, respectively, comparing to those by the optimal preview acceleration (OPA) driver model with the non-preview speed-tracking method. Additionally, the average vehicle speed is increased by 0.26 km/h with the peak sideslip angle suppressed to 1.9°. This research proposes a novel motion controller, which provides the full drive

  16. A study on model fidelity for model predictive control-based obstacle avoidance in high-speed autonomous ground vehicles

    NASA Astrophysics Data System (ADS)

    Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

    2016-11-01

    This paper investigates the level of model fidelity needed in order for a model predictive control (MPC)-based obstacle avoidance algorithm to be able to safely and quickly avoid obstacles even when the vehicle is close to its dynamic limits. The context of this work is large autonomous ground vehicles that manoeuvre at high speed within unknown, unstructured, flat environments and have significant vehicle dynamics-related constraints. Five different representations of vehicle dynamics models are considered: four variations of the two degrees-of-freedom (DoF) representation as lower fidelity models and a fourteen DoF representation with combined-slip Magic Formula tyre model as a higher fidelity model. It is concluded that the two DoF representation that accounts for tyre nonlinearities and longitudinal load transfer is necessary for the MPC-based obstacle avoidance algorithm in order to operate the vehicle at its limits within an environment that includes large obstacles. For less challenging environments, however, the two DoF representation with linear tyre model and constant axle loads is sufficient.

  17. A high speed telemetry data link for an autonomous roving vehicle

    NASA Technical Reports Server (NTRS)

    Cipolle, D. J.

    1980-01-01

    A data link system used on a prototype autonomous roving vehicle is described. This system provides a means of acquiring, formatting, and transmitting information on board the vehicle to a controlling computer. Included is a statement of requirements and the design philosophy. Additionally, interfacing with the rover systems is discussed, along with the overall performance of the telemetry link.

  18. A new semi-active safety control strategy for high-speed railway vehicles

    NASA Astrophysics Data System (ADS)

    Guo, Jin; Xu, Zhengguo; Sun, Youxian

    2015-12-01

    This paper focuses on the safety of railway vehicles. A new semi-active control strategy is proposed based on the skyhook control theory. In view of the main railway vehicle safety performance indicators, the new control strategy aims at reducing the derailment coefficient of railway vehicles by restraining the lateral vibrations of the bogie and the wheelset. Furthermore, to evaluate the improvement of the safety performance brought about by the new control strategy, a complete railway vehicle model is established using the ADAMS/Rail software package. In further co-simulations, five conventional control methods are compared with the proposed approach under the same conditions. Co-simulation results indicate that the new control strategy is effective in improving the safety performance of railway vehicles.

  19. Exhaust emissions of volatile organic compounds of powered two-wheelers: effect of cold start and vehicle speed. Contribution to greenhouse effect and tropospheric ozone formation.

    PubMed

    Costagliola, M Antonietta; Murena, Fabio; Prati, M Vittoria

    2014-01-15

    Powered two-wheeler (PTW) vehicles complying with recent European type approval standards (stages Euro 2 and Euro 3) were tested on chassis dynamometer in order to measure exhaust emissions of about 25 volatile organic compounds (VOCs) in the range C1-C7, including carcinogenic compounds as benzene and 1,3-butadiene. The fleet consists of a moped (engine capacity ≤ 50 cm(3)) and three fuel injection motorcycles of different engine capacities (150, 300 and 400 cm(3)). Different driving conditions were tested (US FPT cycle, constant speed). Due to the poor control of the combustion and catalyst efficiency, moped is the highest pollutant emitter. In fact, fuel injection strategy and three way catalyst with lambda sensor are able to reduce VOC motorcycles' emission of about one order of magnitude with respect to moped. Cold start effect, that is crucial for the assessment of actual emission of PTWs in urban areas, was significant: 30-51% of extra emission for methane. In the investigated speed range, moped showed a significant maximum of VOC emission factor at minimum speed (10 km/h) and a slightly decreasing trend from 20 to 60 km/h; motorcycles showed on the average a less significant peak at 10 km/h, a minimum at 30-40 km/h and then an increasing trend with a maximum emission factor at 90 km/h. Carcinogenic VOCs show the same pattern of total VOCs. Ozone Formation Potential (OFP) was estimated by using Maximum Incremental Reactivity scale. The greatest contribution to tropospheric ozone formation comes from alkenes group which account for 50-80% to the total OFP. VOC contribution effect on greenhouse effect is negligible with respect to CO2 emitted.

  20. Modification of a Nose Cone for a REMUS 100 Autonomous Underwater Vehicle to Improve Low-Speed Stability

    DTIC Science & Technology

    2009-10-01

    In support of these activities, DSTO has purchased a ‘REMUS 100’ hand-deployable AUV fitted with high-resolution sidescan sonar and a high-accuracy...track to across-track ‘aspect’ ratio in the sidescan sonar imagery. The REMUS operator’s manual advises that the vehicle is operable at speeds between...frequency (900/1800 kHz) sidescan sonar , 13 DSTO-TN-0876 14  A Kearfott T-16 Inertial Navigation System,  A Woods Hole Oceanographic Institute

  1. Generic vehicle speed models based on traffic simulation: Development and application

    SciTech Connect

    Margiotta, R.; Cohen, H.; Elkins, G.; Rathi, A.; Venigalla, M.

    1994-12-15

    This paper summarizes the findings of a research project to develop new methods of estimating speeds for inclusion in the Highway Performance Monitoring System (HPMS) Analytical Process. The paper focuses on the effects of traffic conditions excluding incidents (recurring congestion) on daily average ed and excess fuel consumption. A review of the literature revealed that many techniques have been used to predict speeds as a function of congestion but most fail to address the effects of queuing. However, the method of Dowling and Skabardonis avoids this limitation and was adapted to the research. The methodology used the FRESIM and NETSIM microscopic traffic simulation models to develop uncongested speed functions and as a calibration base for the congested flow functions. The chief contributions of the new speed models are the simplicity of application and their explicit accounting for the effects of queuing. Specific enhancements include: (1) the inclusion of a queue discharge rate for freeways; (2) use of newly defined uncongested flow speed functions; (3) use of generic temporal distributions that account for peak spreading; and (4) a final model form that allows incorporation of other factors that influence speed, such as grades and curves. The main limitation of the new speed models is the fact that they are based on simulation results and not on field observations. They also do not account for the effect of incidents on speed. While appropriate for estimating average national conditions, the use of fixed temporal distributions may not be suitable for analyzing specific facilities, depending on observed traffic patterns. Finally, it is recommended that these and all future speed models be validated against field data where incidents can be adequately identified in the data.

  2. 76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-03

    ... speeding, tailgating, and abrupt lane changes. These commenters expressed the belief that limiting the... time that will allow manufacturers to undergo a systems integration process. The change to the...

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  4. An MPC Algorithm with Combined Speed and Steering Control for Obstacle Avoidance in Autonomous Ground Vehicles

    DTIC Science & Technology

    2015-04-24

    Borrelli, “A unified approach to threat assessment and control for automotive active safety,” IEEE Transactions On Intelligent Transportation Systems , vol...Proceedings of ASME 2015 Dynamic Systems and Control Conference DSCC 2015 October 28-30, 2015, Ohio, USA DSCC2015 - 9747 AN MPC ALGORITHM WITH... INTRODUCTION Obstacle avoidance is a critical capability for autonomous ground vehicles (AGVs). It refers to the task of sensing the vehicle’s

  5. 49 CFR 571.500 - Standard No. 500; Low-speed vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Reflex reflectors: one red on each side as far to the rear as practicable, and one red on the rear, (6... Paved Surfaces Using a Standard Reference Test Tire,” at a speed of 64.4 km/h (40.0 mph), without...

  6. 49 CFR 571.500 - Standard No. 500; Low-speed vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Reflex reflectors: one red on each side as far to the rear as practicable, and one red on the rear, (6... Paved Surfaces Using a Standard Reference Test Tire,” at a speed of 64.4 km/h (40.0 mph), without...

  7. 49 CFR 571.500 - Standard No. 500; Low-speed vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Reflex reflectors: one red on each side as far to the rear as practicable, and one red on the rear, (6... Paved Surfaces Using a Standard Reference Test Tire,” at a speed of 64.4 km/h (40.0 mph), without...

  8. Effect of In-Vehicle Audio Warning System on Driver’s Speed Control Performance in Transition Zones from Rural Areas to Urban Areas

    PubMed Central

    Yan, Xuedong; Wang, Jiali; Wu, Jiawei

    2016-01-01

    Speeding is a major contributing factor to traffic crashes and frequently happens in areas where there is a mutation in speed limits, such as the transition zones that connect urban areas from rural areas. The purpose of this study is to investigate the effects of an in-vehicle audio warning system and lit speed limit sign on preventing drivers’ speeding behavior in transition zones. A high-fidelity driving simulator was used to establish a roadway network with the transition zone. A total of 41 participants were recruited for this experiment, and the driving speed performance data were collected from the simulator. The experimental results display that the implementation of the audio warning system could significantly reduce drivers’ operating speed before they entered the urban area, while the lit speed limit sign had a minimal effect on improving the drivers’ speed control performance. Without consideration of different types of speed limit signs, it is found that male drivers generally had a higher operating speed both upstream and in the transition zones and have a larger maximum deceleration for speed reduction than female drivers. Moreover, the drivers who had medium-level driving experience had the higher operating speed and were more likely to have speeding behaviors in the transition zones than those who had low-level and high-level driving experience in the transition zones. PMID:27347990

  9. Hunting stability analysis of high-speed railway vehicle trucks on tangent tracks

    NASA Astrophysics Data System (ADS)

    Lee, Sen-Yung; Cheng, Yung-Chang

    2005-04-01

    Using the linear creep model, this paper derives the governing differential equations of motion for a truck moving on tangent tracks. The truck is modeled by a 10 degree-of-freedom (DOF) system which considers the lateral displacement, vertical displacement, roll angle and yaw angle of each wheelset and the lateral displacement and yaw angle of the truck frame. It is shown that the critical hunting speeds evaluated using the 10-DOF system differ significantly from those calculated using a system with six-DOF. The influences on the critical hunting speeds of certain physical parameters not considered in the six-DOF system are evaluated for wheels of different conicities. The accuracy of the present analysis is verified by comparing the limiting case and the current numerical results with the findings available in published literature.

  10. In-flight flow visualization with pressure measurements at low speeds on the NASA F-18 high alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Delfrate, John H.; Fisher, David F.; Zuniga, Fanny A.

    1990-01-01

    In-flight results from surface and off-surface flow visualizations and from extensive pressure distributions document the vortical flow on the leading edge extensions (LEX) and forebody of the NASA F-18 high alpha research vehicle for low speeds and angles of attack up to 50 degs. Surface flow visualization data, obtained using the emitted fluid technique, were used to define separation lines and laminar separation bubbles. Off-surface flow visualization data, obtained by smoke injection, were used to document both the path of the vortex cores and the location of vortex core breakdown. The location of vortex core breakdown correlated well with the loss of suction pressure on the LEX and with the flow visualization results from ground facilities. Surface flow separation lines on the LEX and forebody corresponded well with the end of pressure recovery under the vortical flows. Correlation of the pressures with wind tunnel results show fair to good correlation.

  11. Thermostructural applications of heat pipes for cooling leading edges of high-speed aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Camarda, Charles J.; Glass, David E.

    1992-01-01

    Heat pipes have been considered for use on wing leading edge for over 20 years. Early concepts envisioned metal heat pipes cooling a metallic leading edge. Several superalloy/sodium heat pipes were fabricated and successfully tested for wing leading edge cooling. Results of radiant heat and aerothermal testing indicate the feasibility of using heat pipes to cool the stagnation region of shuttle-type space transportation systems. The test model withstood a total seven radiant heating tests, eight aerothermal tests, and twenty-seven supplemental radiant heating tests. Cold-wall heating rates ranged from 21 to 57 Btu/sq ft-s and maximum operating temperatures ranged from 1090 to 1520 F. Follow-on studies investigated the application of heat pipes to cool the stagnation regions of single-stage-to-orbit and advanced shuttle vehicles. Results of those studies indicate that a 'D-shaped' structural design can reduce the mass of the heat-pipe concept by over 44 percent compared to a circular heat-pipe geometry. Simple analytical models for heat-pipe startup from the frozen state (working fluid initially frozen) were adequate to approximate transient, startup, and steady-state heat-pipe performance. Improvement in analysis methods has resulted in the development of a finite-element analysis technique to predict heat-pipe startup from the frozen state. However, current requirements of light-weight design and reliability suggest that metallic heat pipes embedded in a refractory composite material should be used. This concept is the concept presently being evaluated for NASP. A refractory-composite/heat-pipe-cooled wing leading edge is currently being considered for the National Aero-Space Plane (NASP). This concept uses high-temperature refractory-metal/lithium heat pipes embedded within a refractory-composite structure and is significantly lighter than an actively cooled wing leading edge because it eliminates the need for active cooling during ascent and descent. Since the

  12. Advanced weigh-in-motion system for weighing vehicles at high speed

    SciTech Connect

    Beshears, D.L.; Muhs, J.D.; Scudiere, M.B.

    1998-02-01

    A state-of-the-art, Advanced Weigh-In-Motion (WIM) system has been designed, installed, and tested on the west bound side of Interstate I-75/I-40 near the Knox County Weigh Station. The project is a Cooperative Research and Development Agreement (CRADA) between Oak Ridge National Laboratory (ORNL) and International Road Dynamics, Inc. (IRD) sponsored by the Office of Uranium Programs, Facility and Technology Management Division of the Department of Energy under CRADA No. ORNL95-0364. ORNL, IRD, the Federal Highway Administration, the Tennessee Department of Safety and the Tennessee Department of Transportation have developed a National High Speed WIM Test Facility for test and evaluation of high-speed WIM systems. The WIM system under evaluation includes a Single Load Cell WIM scale system supplied and installed by IRD. ORNL developed a stand-alone, custom data acquisition system, which acquires the raw signals from IRD`s in-ground single load cell transducers. Under a separate contract with the Federal Highway Administration, ORNL designed and constructed a laboratory scale house for data collection, analysis and algorithm development. An initial advanced weight-determining algorithm has been developed. The new advanced WIM system provides improved accuracy and can reduce overall system variability by up to 30% over the existing high accuracy commercial WIM system.

  13. Effects of major-road vehicle speed and driver age and gender on left-turn gap acceptance.

    PubMed

    Yan, Xuedong; Radwan, Essam; Guo, Dahai

    2007-07-01

    Because the driver's gap-acceptance maneuver is a complex and risky driving behavior, it is a highly concerned topic for traffic safety and operation. Previous studies have mainly focused on the driver's gap acceptance decision itself but did not pay attention to the maneuver process and driving behaviors. Using a driving simulator experiment for left-turn gap acceptance at a stop-controlled intersection, this study evaluated the effects of major traffic speed and driver age and gender on gap acceptance behaviors. The experiment results illustrate relationships among drivers' left-turn gap decision, driver's acceleration rate, steering action, and the influence of the gap-acceptance maneuver on the vehicles in the major traffic stream. The experiment results identified an association between high crash risk and high traffic speed at stop-controlled intersections. The older drivers, especially older female drivers, displayed a conservative driving attitude as a compensation for reduced driving ability, but also showed to be the most vulnerable group for the relatively complex driving maneuvers.

  14. Emissions from US waste collection vehicles

    SciTech Connect

    Maimoun, Mousa A.; Reinhart, Debra R.; Gammoh, Fatina T.; McCauley Bush, Pamela

    2013-05-15

    Highlights: ► Life-cycle emissions for alternative fuel technologies. ► Fuel consumption of alternative fuels for waste collection vehicles. ► Actual driving cycle of waste collection vehicles. ► Diesel-fueled waste collection vehicle emissions. - Abstract: This research is an in-depth environmental analysis of potential alternative fuel technologies for waste collection vehicles. Life-cycle emissions, cost, fuel and energy consumption were evaluated for a wide range of fossil and bio-fuel technologies. Emission factors were calculated for a typical waste collection driving cycle as well as constant speed. In brief, natural gas waste collection vehicles (compressed and liquid) fueled with North-American natural gas had 6–10% higher well-to-wheel (WTW) greenhouse gas (GHG) emissions relative to diesel-fueled vehicles; however the pump-to-wheel (PTW) GHG emissions of natural gas waste collection vehicles averaged 6% less than diesel-fueled vehicles. Landfill gas had about 80% lower WTW GHG emissions relative to diesel. Biodiesel waste collection vehicles had between 12% and 75% lower WTW GHG emissions relative to diesel depending on the fuel source and the blend. In 2011, natural gas waste collection vehicles had the lowest fuel cost per collection vehicle kilometer travel. Finally, the actual driving cycle of waste collection vehicles consists of repetitive stops and starts during waste collection; this generates more emissions than constant speed driving.

  15. Two-Speed Epicyclic Final Drives for 14-Ton Amphibious Vehicle

    DTIC Science & Technology

    1985-01-18

    inside F’.D.(oF) 17:45:01 13:50:01 13:55:01 14:00:00 14z05z00 FD Output Fowe- (hp) 32 31 31 32 31 Output T orque (lb-ft) 1674 1663 1645 1475 1448 FD Output...Output T orque (lb-f!) -47) -486 -430 -387 -509 FD Output Saeed(rp) 367 36. 367 Z66 367 FD Input Speed (rpm) 1642 1642 1642 1645 1644 Pump Spend (rpm...08s24,12 08&25CO0 08:30:01 08:37g17 0840,01 FD Output Power (hp) 42 62 30 71 63 OutFut ’ orque (lb-fL) 471 706 i01e 1607 1407 FD Out.ut Soeed ipm) 465

  16. Effectiveness of a Program Using a Vehicle Tracking System, Incentives, and Disincentives to Reduce the Speeding Behavior of Drivers with ADHD

    ERIC Educational Resources Information Center

    Markham, Paula T.; Porter, Bryan E.; Ball, J. D.

    2013-01-01

    Objective: In this article, the authors investigated the effectiveness of a behavior modification program using global positioning system (GPS) vehicle tracking devices with contingency incentives and disincentives to reduce the speeding behavior of drivers with ADHD. Method: Using an AB multiple-baseline design, six participants drove a 5-mile…

  17. Study of Aerothermodynamic Modeling Issues Relevant to High-Speed Sample Return Vehicles

    NASA Technical Reports Server (NTRS)

    Johnston, Christopher O.

    2014-01-01

    This paper examines the application of state-of-the-art coupled ablation and radiation simulations to highspeed sample return vehicles, such as those returning from Mars or an asteroid. A defining characteristic of these entries is that the surface recession rates and temperatures are driven by nonequilibrium convective and radiative heating through a boundary layer with significant surface blowing and ablation products. Measurements relevant to validating the simulation of these phenomena are reviewed and the Stardust entry is identified as providing the best relevant measurements. A coupled ablation and radiation flowfield analysis is presented that implements a finite-rate surface chemistry model. Comparisons between this finite-rate model and a equilibrium ablation model show that, while good agreement is seen for diffusion-limited oxidation cases, the finite-rate model predicts up to 50% lower char rates than the equilibrium model at sublimation conditions. Both the equilibrium and finite rate models predict significant negative mass flux at the surface due to sublimation of atomic carbon. A sensitivity analysis to flowfield and surface chemistry rates show that, for a sample return capsule at 10, 12, and 14 km/s, the sublimation rates for C and C3 provide the largest changes to the convective flux, radiative flux, and char rate. A parametric uncertainty analysis of the radiative heating due to radiation modeling parameters indicates uncertainties ranging from 27% at 10 km/s to 36% at 14 km/s. Applying the developed coupled analysis to the Stardust entry results in temperatures within 10% of those inferred from observations, and final recession values within 20% of measurements, which improves upon the 60% over-prediction at the stagnation point obtained through an uncoupled analysis. Emission from CN Violet is shown to be over-predicted by nearly and order-of-magnitude, which is consistent with the results of previous independent analyses. Finally, the

  18. [Airborne Japanese cedar allergens studied by immunoblotting technique using anti-Cry j I monoclonal antibody--comparison with actual pollen counts and effect of wind speed and directions].

    PubMed

    Iwaya, M; Murakami, G; Matsuno, M; Onoue, Y; Takayanagi, M; Kayahara, M; Adachi, Y; Adachi, Y; Okada, T; Kenda, S

    1995-07-01

    We collected airborne particles of Japanese cedar pollen with Burkard's sampling tape in Toyama from February to April 1992. The tape was cut into two pieces in parallel to time axis. The one of piece of the tapes was stained with glycerin-jerry and stained pollens were counted with a microscope. The other piece was treated according to the immunoblotting technique. The airborne pollen allergens, reacting with anti-Cry j I monoclonal antibody, were stained as blue spots. The spots were classified by diameter into two groups, large spots (> 50 microns) and small spots (< 50 microns). There were significant correlations found between the airborne Cry j I allergen spots (in large and small) and actual pollen counts obtained with the Burkard's sampler and the Durham's sampler (r = 0.729, 0.586 in large spots and r = 0.676, 0.489 in small spots, p < 0.001). The counts of small spots stayed in high level even in April when actual pollen counts decreased. We concluded that this discrepancy was caused by allergenic crushed cedar pollen particles staying floating longer than actual pollens. Secondly we set a gauge of wind speed and direction at the same point as the samplers. The actual pollen counts and large spots counts were significantly larger in the wind (SE wind in Toyama city) from cedar trees blooming area than other areas. However small spots counts did not differ significantly according to wind directions. Wind speed did not effect on actual pollen counts, large spots counts and small spots count.

  19. Potential of spark ignition engine, effect of vehicle design variables on top speed, performance, and fuel economy. Final report

    SciTech Connect

    Zub, R.W.; Neckyfarow, C.M.; Lew, W.M.; Colello, R.G.

    1980-03-01

    The purpose of this report is to evaluate the effect of vehicle characteristics on vehicle performance and fuel economy. The studies were performed using the VEHSIM (vehicle simulation) program at the Transportation Systems Center. The computer simulation offers repeatability and can predict minute changes in fuel economy based on relatively small vehicle alterations. The degree to which each vehicle parameter is modified is based upon projections presented in current literature. The results are assessed and an explanation of the interaction of the vehicle design characteristics on performance is presented.

  20. [Dose loads on and radiation risk values for cosmonauts on a mission to Mars estimated from actual Martian vehicle engineering development].

    PubMed

    Shafirkin, A V; Kolomenskiĭ, A V; Mitrikas, V G; Petrov, V M

    2010-01-01

    The current design philosophy of a Mars orbiting vehicle, takeoff and landing systems and the transport return vehicle was taken into consideration for calculating the equivalent doses imparted to cosmonaut's organs and tissues by galactic cosmic rays, solar rays and the Earth's radiation belts, values of the total radiation risk over the lifespan following the mission and over the whole career period, and possible shortening of life expectancy. There are a number of uncertainties that should be evaluated, and radiation limits specified before setting off to Mars.

  1. Effect of stiffness and movement speed on selected dynamic torque characteristics of hydraulic-actuation joystick controls for heavy vehicles.

    PubMed

    Oliver, Michele; Rogers, Robert; Rickards, Jeremy; Tingley, Maureen; Biden, Edmund

    2006-02-22

    The purpose of this work was to quantify the effects of joystick stiffness and movement speed on the dynamic torque characteristics of hydraulic-actuation joystick controls, as found in off-road vehicles, as one of the initial steps towards the development of a joystick design protocol. Using a previously developed mathematical model in which a hydraulic-actuation joystick is assumed to rotate about two axes where the rotation origin is a universal joint, the dynamic torque characteristics incurred by an operator were predicted. Utilizing a laboratory mock-up of an excavator cab environment, three actuation torque characteristics (peak torque, angular impulse and deceleration at the hard endpoint) were quantified for nine unskilled joystick operators during the use of a commonly used North American hydraulic-actuation joystick. The six different experimental conditions included combinations of three joystick stiffnesses and two movement speeds. The highest instantaneous input torque over the course of the joystick movement (not including the hard endpoint) was evaluated using the peak torque value. Angular impulse provided an indication of the sustained exposure to force. The third indicator, deceleration at the hard endpoint, was included to provide a description of impact loading on the hand as the joystick came to a sudden stop. The most important result of this work is that the dynamic torque characteristics incurred during hydraulic-actuation joystick use are substantial. While the peak torque values were not very different between the fast and slow motion conditions, the high decelerations even for slow movements observed at maximum excursion of the joystick indicate that the dynamics do matter. On the basis of deceleration at the hard endpoint and peak torque, the joystick movements that require the highest values for a combination of torque variables are the side-to-side ones. This suggests that less stiff balance and return springs should be considered for

  2. Effects of Pay-As-You-Drive vehicle insurance on young drivers' speed choice: results of a Dutch field experiment.

    PubMed

    Bolderdijk, J W; Knockaert, J; Steg, E M; Verhoef, E T

    2011-05-01

    Speeding is an important cause for young drivers' involvement in traffic accidents. A reduction in driving speeds of this group could result in fewer accidents. One way of reducing driving speed is offering explicit financial incentives. In collaboration with five Dutch car insurance companies, we tested the effects of a Pay-As-You-Drive insurance fee on driving speed. A group of young drivers could save money on their monthly insurance fee by keeping the speed limit. Driving speed was monitored through GPS technology during one year. Analyses showed that, relative to pre- and post-measurement, as well as a control group, the introduction of a Pay-As-You-Drive insurance fee significantly reduced speed violations of young drivers.

  3. Attenuation of low-frequency electromagnetic wave in the thin sheath enveloping a high-speed vehicle upon re-entry

    NASA Astrophysics Data System (ADS)

    Liu, DongLin; Li, XiaoPing; Liu, YanMing; Xie, Kai; Bai, BoWen

    2017-02-01

    Low-frequency (LF) electromagnetic (EM) waves are suggested as potentially solving "radio blackout" caused by a plasma sheath enveloping a high-speed vehicle on re-entry. However, the traditional plasma absorption theory neglects the fact that the plasma sheath is electrically small compared to LF EM wavelengths. To understand clearly the attenuation of such waves through the plasma sheath, different attenuation mechanisms for the electric field (SE) and magnetic field (SH) were studied using the equivalent circuit approach. Analytical expressions were derived by modeling the plasma sheath as a spherical shell, and numerical simulations were performed to validate the effectiveness of the expressions. SE and SH are calculated for various plasma parameter settings; the EM wave attenuations obtained from plasma absorption theory are used for comparison. Results show that, instead of SE and SH being equal in the plasma absorption theory, SE and SH are no longer the same for electrically small sizes. Whereas |SH| is close to that from plasma absorption theory, |SE| is much higher. Further analysis shows that |SH| is a function of the ratio of electron density (ne) and collision frequency (ve) and increases with increasing ne/ve. Numerical simulations with radio-attenuation-measurement-C-like vehicle's plasma sheath parameters are performed and the results show that the magnetic field attenuation in the front part of the vehicle is much lower than in the rear. So it is suggested to place the magnetic loop antenna in the very front part of the vehicle. Finally, SH at different frequencies are calculated using plasma sheath parameter values simulating the re-entry phase of a radio-attenuation measurement-C vehicle and results show that such a vehicle might overcome radio blackout during the entire re-entry phase if systems operating below 3 MHz and above the L-band are combined with a lower-frequency system working below Earth's ionosphere and a higher-frequency system

  4. A Simulation Study of a Speed Control System for Autonomous On-Road Operation of Automotive Vehicles.

    DTIC Science & Technology

    1987-06-01

    control signals sent to the vehicle.[Ref. 81 In another study of vehicle automatic longitudinal control, Bender, Fenton, and Olson investigated a car ...includes all types of driverless industrial trucks, such as fork trucks and electric tractors. Due to industrial demands. AGV’s also include different...types of conveyor assemblies and trolleys. However. the discussion to follow is limited to driverless industrial trucks. Successful research with

  5. An estimation of vehicle kilometer traveled and on-road emissions using the traffic volume and travel speed on road links in Incheon City.

    PubMed

    Jung, Sungwoon; Kim, Jounghwa; Kim, Jeongsoo; Hong, Dahee; Park, Dongjoo

    2017-04-01

    The objective of this study is to estimate the vehicle kilometer traveled (VKT) and on-road emissions using the traffic volume in urban. We estimated two VKT; one is based on registered vehicles and the other is based on traffic volumes. VKT for registered vehicles was 2.11 times greater than that of the applied traffic volumes because each VKT estimation method is different. Therefore, we had to define the inner VKT is moved VKT inner in urban to compare two values. Also, we focused on freight modes because these are discharged much air pollutant emissions. From analysis results, we found middle and large trucks registered in other regions traveled to target city in order to carry freight, target city has included many industrial and logistics areas. Freight is transferred through the harbors, large logistics centers, or via locations before being moved to the final destination. During this process, most freight is moved by middle and large trucks, and trailers rather than small trucks for freight import and export. Therefore, these trucks from other areas are inflow more than registered vehicles. Most emissions from diesel trucks had been overestimated in comparison to VKT from applied traffic volumes in target city. From these findings, VKT is essential based on traffic volume and travel speed on road links in order to estimate accurately the emissions of diesel trucks in target city. Our findings support the estimation of the effect of on-road emissions on urban air quality in Korea.

  6. Incidence of paediatric fatal and non-fatal low speed vehicle run over events in Queensland, Australia: eleven year analysis

    PubMed Central

    2014-01-01

    Background The purpose of this study was to estimate the incidence of fatal and non-fatal Low Speed Vehicle Run Over (LSVRO) events among children aged 0–15 years in Queensland, Australia, at a population level. Methods Fatal and non-fatal LSVRO events that occurred in children resident in Queensland over eleven calendar years (1999-2009) were identified using ICD codes, text description, word searches and medical notes clarification, obtained from five health related data bases across the continuum of care (pre-hospital to fatality). Data were manually linked. Population data provided by the Australian Bureau of Statistics were used to calculate crude incidence rates for fatal and non-fatal LSVRO events. Results There were 1611 LSVROs between 1999–2009 (IR = 16.87/100,000/annum). Incidence of non-fatal events (IR = 16.60/100,000/annum) was 61.5 times higher than fatal events (IR = 0.27/100,000/annum). LSVRO events were more common in boys (IR = 20.97/100,000/annum) than girls (IR = 12.55/100,000/annum), and among younger children aged 0–4 years (IR = 21.45/100000/annum; 39% or all events) than older children (5–9 years: IR = 16.47/100,000/annum; 10–15 years IR = 13.59/100,000/annum). A total of 896 (56.8%) children were admitted to hospital for 24 hours of more following an LSVRO event (IR = 9.38/100,000/annum). Total LSVROs increased from 1999 (IR = 14.79/100,000) to 2009 (IR = 18.56/100,000), but not significantly. Over the 11 year period, there was a slight (non –significant) increase in fatalities (IR = 0.37-0.42/100,000/annum); a significant decrease in admissions (IR = 12.39–5.36/100,000/annum), and significant increase in non-admissions (IR = 2.02-12.77/100,000/annum). Trends over time differed by age, gender and severity. Conclusion This is the most comprehensive, population-based epidemiological study on fatal and non-fatal LSVRO events to date. Results from this study indicate

  7. Automatic speed control of highway traffic

    NASA Technical Reports Server (NTRS)

    Klingman, E. E.

    1973-01-01

    Vehicle control system monitors all vehicles in its range, and automatically slows down speeding vehicles by activating governor in vehicle. System determines only maximum speed; speeds below maximum are controlled by vehicle operator. Loss of transmitted signal or activation of emergency over-ride will open fuel line and return control to operator.

  8. Controlled Speed Accessory Drive demonstration program

    NASA Technical Reports Server (NTRS)

    Hoehn, F. W.

    1981-01-01

    A Controlled Speed Accessory Drive System was examined in an effort to improve the fuel economy of passenger cars. Concept feasibility and the performance of a typical system during actual road driving conditions were demonstrated. The CSAD system is described as a mechanical device which limits engine accessory speeds, thereby reducing parasitic horsepower losses and improving overall vehicle fuel economy. Fuel consumption data were compiled for fleets of GSA vehicles. Various motor pool locations were selected, each representing different climatic conditions. On the basis of a total accumulated fleet usage of nearly three million miles, an overall fuel economy improvement of 6 percent to 7 percent was demonstrated. Coincident chassis dynamometer tests were accomplished on selected vehicles to establish the effect of different accessory drive systems on exhaust emissions, and to evaluate the magnitude of the mileage benefits which could be derived.

  9. Effect of joystick stiffness, movement speed and movement direction on joystick and upper limb kinematics when using hydraulic-actuation joystick controls in heavy vehicles.

    PubMed

    Oliver, M; Tingley, M; Rogers, R; Rickards, J; Biden, E

    2007-06-01

    Despite the widespread use of hydraulic-actuation joysticks in mobile North American construction, mining and forestry vehicles, the biomechanical effects that joysticks have on their human operators has not been studied extensively. Using nine unskilled joystick operators and a laboratory mock-up with a commonly used North American heavy off-road equipment hydraulic-actuation joystick and operator seat, the purpose of this work was to quantify and compare the effects of three hydraulic-actuation joystick stiffnesses and two movement speeds on upper limb and joystick kinematics as one of the initial steps towards the development of a hydraulic-actuation joystick design protocol. In addition to providing a detailed description of the kinematics of a constrained occupational task, coupled with the corresponding effects of the task on operator upper limb kinematics, results from principal component analysis and ANOVA procedures revealed a number of differences in joystick and upper limb angle ranges and movement curve shapes resulting from the various joystick stiffness-speed combinations tested. For the most part, these joystick motion alterations were caused by small, insignificant changes in one or more upper limb joint angles. The two exceptions occurred for forward movements of the joystick; the fast speed - light stiffness condition movement pattern shape change was caused primarily by an alteration of the elbow flexion-extension movement pattern. Similarly, the fast speed - normal stiffness condition movement curve shape perturbation - was caused principally by a combination of significant movement curve shape alterations to elbow flexion-extension, external-internal shoulder rotation and flexion-extension of the shoulder. The finding that joystick stiffness and speed alterations affect joystick and upper limb kinematics minimally indicates that the joystick design approach of modelling the joystick and operator upper limb as a closed linkage system should be

  10. Flight-determined aerodynamic stability and control derivatives of the M2-F2 lifting body vehicle at subsonic speeds

    NASA Technical Reports Server (NTRS)

    Kempel, R. W.; Thompson, R. C.

    1971-01-01

    Aerodynamic derivatives were obtained for the M2-F2 lifting body flight vehicle in the subsonic flight region between Mach numbers of 0.41 and 0.64 and altitudes of 7000 feet to 45,000 feet. The derivatives were determined by a flight time history curve-fitting process utilizing a hybrid computer. The flight-determined derivatives are compared with wind-tunnel and predicted values. Modal-response characteristics, calculated from the flight derivatives, are presented.

  11. Vehicle-based road dust emission measurement (III):. effect of speed, traffic volume, location, and season on PM 10 road dust emissions in the Treasure Valley, ID

    NASA Astrophysics Data System (ADS)

    Etyemezian, V.; Kuhns, H.; Gillies, J.; Chow, J.; Hendrickson, K.; McGown, M.; Pitchford, M.

    The testing re-entrained aerosol kinetic emissions from roads (TRAKER) road dust measurement system was used to survey more than 400 km of paved roads in southwestern Idaho during 3-week sampling campaigns in winter and summer, 2001. Each data point, consisting of a 1-s measurement of particle light scattering sampled behind the front tire, was associated with a link (section of road) in the traffic demand model network for the Treasure Valley, ID. Each link was in turn associated with a number of characteristics including posted speed limit, vehicle kilometers traveled (vkt), road class (local/residential, collector, arterial, and interstate), county, and land use (urban vs. rural). Overall, the TRAKER-based emission factors based on location, setting, season, and speed spanned a narrow range from 3.6 to 8.0 g/vkt. Emission factors were higher in winter compared to summer, higher in urban areas compared to rural, and lower for roads with fast travel speeds compared to slower roads. The inherent covariance between traffic volume and traffic speed obscured the assessment of the effect of traffic volume on emission potentials. Distance-based emission factors expressed in grams per kilometer traveled (g/vkt) for roads with low travel speeds (˜11 m/s residential roads) compared to those with high travel speeds (˜25 m/s interstates) were higher (5.2 vs. 3.0 g/vkt in summer and 5.9 vs. 4.9 g/vkt in winter). However, emission potentials which characterize the amount of suspendable material on a road were substantially higher on roads with low travel speeds (0.71 vs. 0.13 g/vkt/(m/s) in summer and 0.78 vs. 0.21 g/vkt/(m/s) in winter). This suggested that while high speed roads are much cleaner (factor of 5.4 in summer), on a vehicle kilometer traveled basis, emissions from high and low speed roads are of the same order. Emission inventories based on the TRAKER method, silt loadings obtained during the field study, and US EPA's AP-42 default values of silt loading were

  12. Developing a high-resolution vehicular emission inventory by integrating an emission model and a traffic model: Part 1--Modeling fuel consumption and emissions based on speed and vehicle-specific power.

    PubMed

    Wang, Haikun; Fu, Lixin

    2010-12-01

    To improve the accuracy and applicability of vehicular emission models, this study proposes a speed and vehicle-specific power (VSP) modeling method to estimate vehicular emissions and fuel consumption using data gathered by a portable emissions monitoring system (PEMS). The PEMS data were categorized into discrete speed-VSP bins on the basis of the characteristics of vehicle driving conditions and emissions in Chinese cities. Speed-VSP modal average rates of emissions (or fuel consumption) and the time spent in the corresponding speed-VSP bins were then used to calculate the total trip emissions (or fuel consumption) and emission factors (or fuel economy) under specific average link speeds. The model approach was validated by comparing it against measured data with prediction errors within 20% for trip emissions and link-speed-based emission factors. This analysis is based on the data of light-duty gasoline vehicles in China; however, this research approach could be generalized to other vehicle fleets in other countries. This modeling method could also be coupled with traffic demand models to establish high-resolution emissions inventories and evaluate the impacts of traffic-related emission control measures.

  13. A cycle timer for testing electric vehicles

    NASA Technical Reports Server (NTRS)

    Soltis, R. F.

    1978-01-01

    A cycle timer was developed to assist the driver of an electric vehicle in more accurately following and repeating SAE driving schedules. These schedules require operating an electric vehicle in a selected stop-and-go driving cycle and repeating this cycle pattern until the vehicle ceases to meet the requirements of the cycle. The heart of the system is a programmable read-only memory (PROM) that has the required test profiles permanently recorded on plug-in cards, one card for each different driving schedule. The PROM generates a direct current analog signal that drives a speedometer displayed on one scale of a dual movement meter. The second scale of the dual movement meter displays the actual speed of the vehicle as recorded by the fifth wheel. The vehicle operator controls vehicle speed to match the desired profile speed. The PROM controls the recycle start time as well as the buzzer activation. The cycle programmer is powered by the test vehicle's 12-volt accessory battery, through a 5-volt regulator and a 12-volt dc-to-dc converter.

  14. Low-Subsonic-Speed Static Longitudinal Stability and Control Characteristics of a Winged Reentry-Vehicle Configuration Having Wingtip Panels that Fold up for High-Drag Reentry

    NASA Technical Reports Server (NTRS)

    Ware, George M.

    1960-01-01

    An investigation of the low-subsonic-speed static longitudinal stability and control characteristics of a model of a manned reentry-vehicle configuration capable of high-drag reentry and glide landing has been a made in the Langley free-flight tunnel. The model had a modified 63 deg delta plan-form wing with a fuselage on the upper surface. This configuration had wingtip panels designed to fold up 90 deg for the high-drag reentry phase of the flight and to extend horizontally for the glide landing. Data for the basic configurations and modifications to determine the effects of plan form, wingtip panel incidence, dihedral, and vertical position of the wingtip panels are presented without analysis.

  15. A method of predicting quasi-steady aerodynamics for flutter analysis of high speed vehicles using steady CFD calculations

    NASA Technical Reports Server (NTRS)

    Scott, Robert C.; Pototzky, Anthony S.

    1993-01-01

    High speed linear aerodynamic theories like piston theory and Newtonian impact theory are relatively inexpensive to use for flutter analysis. These theories have limited areas of applicability depending on the configuration and the flow conditions. In addition, these theories lack the ability to capture viscous, shock, and real gas effects. CFD methods can model all of these effects accurately, but the unsteady calculations required for flutter are expensive and often impractical. This paper describes a method for using steady CFD calculations to approximate the generalized aerodynamic forces for a flutter analysis. Example two-and three-dimensional aerodynamic force calculations are provided. In addition, a flutter analysis of a NASP-type wing will be discussed.

  16. Flight Investigation using Variable-Stability Airplanes of Minimum Stability Requirements for High-Speed, High-Altitude Vehicles

    NASA Technical Reports Server (NTRS)

    McFadden, Norman M.; Vomaske, Richard F.; Heinle, Donovan R.

    1961-01-01

    The pilot opinion of the flying qualities of vehicles covering a wide range of longitudinal dynamic characteristics has been determined by the use of a variable-stability airplane. Particular emphasis has been placed on determining the minimum level of stability and control characteristics that the pilot can cope with. There was considerable pilot learning associated with operation in the regions of poor stability characteristics. In the statically stable region the maximum acceptable value of time to damp to half amplitude of the longitudinal mode for normal operation was about 1 second. For emergency conditions the damping could be reduced to zero over most of the frequency range. The extreme lim it of controllability corresponded to a time to double amplitude of the oscillation of about 1 - 1/2 seconds. In the statically unstable region somewhat shorter times to double amplitude were acceptable to the pilots. The boundary for emergency operation corresponded roughly to time to double amplitude of about 2/3 second and the limit of controllability of about l/3 second.

  17. Emissions from U.S. waste collection vehicles.

    PubMed

    Maimoun, Mousa A; Reinhart, Debra R; Gammoh, Fatina T; McCauley Bush, Pamela

    2013-05-01

    This research is an in-depth environmental analysis of potential alternative fuel technologies for waste collection vehicles. Life-cycle emissions, cost, fuel and energy consumption were evaluated for a wide range of fossil and bio-fuel technologies. Emission factors were calculated for a typical waste collection driving cycle as well as constant speed. In brief, natural gas waste collection vehicles (compressed and liquid) fueled with North-American natural gas had 6-10% higher well-to-wheel (WTW) greenhouse gas (GHG) emissions relative to diesel-fueled vehicles; however the pump-to-wheel (PTW) GHG emissions of natural gas waste collection vehicles averaged 6% less than diesel-fueled vehicles. Landfill gas had about 80% lower WTW GHG emissions relative to diesel. Biodiesel waste collection vehicles had between 12% and 75% lower WTW GHG emissions relative to diesel depending on the fuel source and the blend. In 2011, natural gas waste collection vehicles had the lowest fuel cost per collection vehicle kilometer travel. Finally, the actual driving cycle of waste collection vehicles consists of repetitive stops and starts during waste collection; this generates more emissions than constant speed driving.

  18. 36 CFR 4.21 - Speed limits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... devices. (c) Operating a vehicle at a speed in excess of the speed limit is prohibited. (d) An authorized person may utilize radiomicrowaves or other electrical devices to determine the speed of a vehicle on a....21 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR VEHICLES...

  19. A comparison of high-speed flywheels, batteries, and ultracapacitors on the bases of cost and fuel economy as the energy storage system in a fuel cell based hybrid electric vehicle

    NASA Astrophysics Data System (ADS)

    Doucette, Reed T.; McCulloch, Malcolm D.

    Fuel cells aboard hybrid electric vehicles (HEVs) are often hybridized with an energy storage system (ESS). Batteries and ultracapacitors are the most common technologies used in ESSs aboard HEVs. High-speed flywheels are an emerging technology with traits that have the potential to make them competitive with more established battery and ultracapacitor technologies in certain vehicular applications. This study compares high-speed flywheels, ultracapacitors, and batteries functioning as the ESS in a fuel cell based HEV on the bases of cost and fuel economy. In this study, computer models were built to simulate the powertrain of a fuel cell based HEV where high-speed flywheels, batteries, and ultracapacitors of a range of sizes were used as the ESS. A simulated vehicle with a powertrain using each of these technologies was run over two different drive cycles in order to see how the different ESSs performed under different driving patterns. The results showed that when cost and fuel economy were both considered, high-speed flywheels were competitive with batteries and ultracapacitors.

  20. Do speed cameras reduce speeding in urban areas?

    PubMed

    Oliveira, Daniele Falci de; Friche, Amélia Augusta de Lima; Costa, Dário Alves da Silva; Mingoti, Sueli Aparecida; Caiaffa, Waleska Teixeira

    2015-11-01

    This observational study aimed to estimate the prevalence of speeding on urban roadways and to analyze associated factors. The sample consisted of 8,565 vehicles circulating in areas with and without fixed speed cameras in operation. We found that 40% of vehicles 200 meters after the fixed cameras and 33.6% of vehicles observed on roadways without speed cameras were moving over the speed limit (p < 0.001). Motorcycles showed the highest recorded speed (126km/h). Most drivers were men (87.6%), 3.3% of all drivers were using their cell phones, and 74.6% of drivers (not counting motorcyclists) were wearing their seatbelts. On roadway stretches without fixed speed cameras, more women drivers were talking on their cell phones and wearing seatbelts when compared to men (p < 0.05 for both comparisons), independently of speed limits. The results suggest that compliance with speed limits requires more than structural interventions.

  1. The Course of Actualization

    ERIC Educational Resources Information Center

    De Smet, Hendrik

    2012-01-01

    Actualization is traditionally seen as the process following syntactic reanalysis whereby an item's new syntactic status manifests itself in new syntactic behavior. The process is gradual in that some new uses of the reanalyzed item appear earlier or more readily than others. This article accounts for the order in which new uses appear during…

  2. 36 CFR 1004.21 - Speed limits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 1004.21 Parks, Forests, and Public Property PRESIDIO TRUST VEHICLES AND TRAFFIC SAFETY § 1004.21 Speed... traffic control devices. (c) Operating a vehicle at a speed in excess of the speed limit is prohibited. (d) An authorized person may utilize radiomicrowaves or other electrical devices to determine the...

  3. 32 CFR 935.132 - Speed limits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Speed limits. 935.132 Section 935.132 National... WAKE ISLAND CODE Motor Vehicle Code § 935.132 Speed limits. Each person operating a motor vehicle on..., or both; and (b) That does not exceed 40 miles an hour or such lesser speed limit as may be posted....

  4. Nonintrusive shaft speed sensor

    NASA Technical Reports Server (NTRS)

    Barkhoudarian, S.; Wyett, L.; Maram, J.

    1985-01-01

    Reusable rocket engines such as the Space Shuttle Main Engines (SSME), the Orbital Transfer Vehicles (OTV), etc., have throttling capabilities that require real-time, closed-loop control systems of engine propellant flows, combustion temperatures and pressures, and turbopump rotary speeds. In the case of the SSME, there are four turbopumps that require real-time measurement and control of their rotary speeds. Variable-reluctance magnetic speed sensors were designed, fabricated, and tested for all four turbopumps, resulting in the successful implementation and operation of three of these speed sensors during each of the 12 Shuttle flights.

  5. Elevation scanning laser/multi-sensor hazard detection system controller and mirror/mast speed control components. [roving vehicle electromechanical devices

    NASA Technical Reports Server (NTRS)

    Craig, J.; Yerazunis, S. W.

    1978-01-01

    The electro-mechanical and electronic systems involved with pointing a laser beam from a roving vehicle along a desired vector are described. A rotating 8 sided mirror, driven by a phase-locked dc motor servo system, and monitored by a precision optical shaft encoder is used. This upper assembly is then rotated about an orthogonal axis to allow scanning into all 360 deg around the vehicle. This axis is also driven by a phase locked dc motor servo-system, and monitored with an optical shaft encoder. The electronics are realized in standard TTL integrated circuits with UV-erasable proms used to store desired coordinates of laser fire. Related topics such as the interface to the existing test vehicle are discussed.

  6. An Exercise in Vehicle Kinematics and Energetics

    NASA Astrophysics Data System (ADS)

    Fischer, Solomon; Gluck, Paul

    2009-03-01

    We physics teachers are forever in search of real-life applications of the theoretical concepts we teach. In mechanics we often utilize vehicle motion exercises, yet most textbook problems involving these are rather tame and deal with constant acceleration. What often captures the imagination of students is the actual performance of cars they drive: times for accelerating from zero to 100 km/h, top speed, energy consumption, power, and so on. Such data, of major concern to car designers and salesmen, are now readily available on the Internet and in magazines such as Car & Driver and Road & Track for a wide spectrum of vehicles. Their use in the classroom has been recommended in several articles that appeared in this journal.2 When reporting acceleration of vehicles, the first (high-acceleration) stage, as the engine "revs up" to its full power, is usually omitted. A glance at a typical velocity-versus-time curve (Fig. 1, for a MINI Cooper S1a; these data are also used in Figs. 3 and 5) shows that as the velocity increases toward the maximum attainable speed in a finite time, the acceleration decreases. Thus, overtaking a car at high speeds takes much longer than the initial acceleration might suggest—this is most unlike a constant acceleration scenario.

  7. Motor Vehicle Safety

    MedlinePlus

    ... these crashes is one part of motor vehicle safety. Here are some things you can do to ... speed or drive aggressively Don't drive impaired Safety also involves being aware of others. Share the ...

  8. On the hazard of quiet vehicles to pedestrians and drivers.

    PubMed

    Wogalter, Michael S; Lim, Raymond W; Nyeste, Patrick G

    2014-09-01

    The need to produce more efficient and less polluting vehicles has encouraged mass production of alternative energy vehicles, such as hybrid and electric cars. Many of these vehicles are capable of very quiet operation. While reducing noise pollution is desirable, quieter vehicles could negatively affect pedestrian safety because of reduced sound cues compared to louder internal combustion engines. Three studies were performed to investigate people's concern about this issue. In Study 1, a questionnaire completed by 378 people showed substantial positive interest in quiet hybrid and electric cars. However, they also indicated concern about the reduced auditory cues of quiet vehicles. In Study 2, 316 participants rated 14 sounds that could be potentially added to quiet alternative-energy vehicles. The data showed that participants did not want annoying sounds, but preferred adding "engine" and "hum" sounds relative to other types of sounds. In Study 3, 24 persons heard and rated 18 actual sounds within 6 categories that were added to a video of a hybrid vehicle driving by. The sounds most preferred were "engine" followed by "white noise" and "hum". Implications for adding sounds to facilitate pedestrians' detection of moving vehicles and for aiding drivers' awareness of speed are discussed.

  9. Upgraded demonstration vehicle task report

    NASA Technical Reports Server (NTRS)

    Bryant, J.; Hardy, K.; Livingston, R.; Sandberg, J.

    1981-01-01

    Vehicle/battery performance capabilities and interface problems that occurred when upgraded developmental batteries were integrated with upgraded versions of comercially available electric vehicles were investigated. Developmental batteries used included nickel zinc batteries, a nickel iron battery, and an improved lead acid battery. Testing of the electric vehicles and upgraded batteries was performed in the complete vehicle system environment to characterize performance and identify problems unique to the vehicle/battery system. Constant speed tests and driving schedule range tests were performed on a chassis dynamometer. The results from these tests of the upgraded batteries and vehicles were compared to performance capabilities for the same vehicles equipped with standard batteries.

  10. Emergency-vehicle VHF antenna

    NASA Technical Reports Server (NTRS)

    Anderson, R. E.; Carlson, A. W.; Lewis, J.

    1977-01-01

    Helical VHF antenna mounts on roof of moving vehicle to communicate with distant stations via earth satellites. Antenna requires no pointing and can provide two-way communication while vehicle moves at high speed. Device has proved extremely successful in electrocardiogram transmission tests between medical services vehicle and hospital emergency room.

  11. Do speed cameras reduce collisions?

    PubMed

    Skubic, Jeffrey; Johnson, Steven B; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

    2013-01-01

    We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods - before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not independently affect the incidence of motor vehicle collisions.

  12. Monitoring speed before and during a speed publicity campaign.

    PubMed

    van Schagen, Ingrid; Commandeur, Jacques J F; Goldenbeld, Charles; Stipdonk, Henk

    2016-12-01

    Driving speeds were monitored during a period of 16 weeks encompassing different stages of an anti-speeding campaign in the Netherlands. This campaign targeted speed limit violations in built-up areas. The observation periods differed in terms of intensity and media used for the campaign. Small road-side radars, mounted in light poles, were used and registered the speeds on 20 locations in built-up areas. Speeds of over 10 million vehicles were measured. Ten locations had a posted speed limit of 50km/h; the other ten had a posted speed limit of 30km/h. Posters were placed at half of each group of locations to remind drivers of the speed limit. The average speed on the 50km/h roads was 46.2km/h, and 36.1km/h on the 30km/h roads. The average proportions of vehicles exceeding the speed limit were 33.3% and 70.1% respectively. For the 30km/h roads, the data shows differences in speed and speeding behaviour between the six distinguished observation periods, but overall these differences cannot be logically linked to the contents of the phases and, hence, cannot be explained as an effect of the campaign. The only exception was an effect of local speed limit reminders on the 30km/h roads. This effect, however, was temporary and had disappeared within a week.

  13. 15 CFR 265.12 - Speeding or reckless driving.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Speeding or reckless driving. 265.12... Speeding or reckless driving. (a) No person shall drive a motor vehicle on the site at a speed greater than... posted, and no person shall drive a motor vehicle on the site in excess of the speed limit....

  14. 15 CFR 265.12 - Speeding or reckless driving.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Speeding or reckless driving. 265.12... Speeding or reckless driving. (a) No person shall drive a motor vehicle on the site at a speed greater than... posted, and no person shall drive a motor vehicle on the site in excess of the speed limit....

  15. 15 CFR 265.12 - Speeding or reckless driving.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Speeding or reckless driving. 265.12... Speeding or reckless driving. (a) No person shall drive a motor vehicle on the site at a speed greater than... posted, and no person shall drive a motor vehicle on the site in excess of the speed limit....

  16. 15 CFR 265.12 - Speeding or reckless driving.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Speeding or reckless driving. 265.12... Speeding or reckless driving. (a) No person shall drive a motor vehicle on the site at a speed greater than... posted, and no person shall drive a motor vehicle on the site in excess of the speed limit....

  17. 15 CFR 265.12 - Speeding or reckless driving.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Speeding or reckless driving. 265.12... Speeding or reckless driving. (a) No person shall drive a motor vehicle on the site at a speed greater than... posted, and no person shall drive a motor vehicle on the site in excess of the speed limit....

  18. Judging arrival times of incoming traffic vehicles is not a prerequisite for safely crossing an intersection: Differential effects of vehicle size and type in passive judgment and active driving tasks.

    PubMed

    Mathieu, Julie; Bootsma, Reinoud J; Berthelon, Catherine; Montagne, Gilles

    2017-02-01

    Using a fixed-base driving simulator we compared the effects of the size and type of traffic vehicles (i.e., normal-sized or double-sized cars or motorcycles) approaching an intersection in two different tasks. In the perceptual judgment task, passively moving participants estimated when a traffic vehicle would reach the intersection for actual arrival times (ATs) of 1, 2, or 3s. In line with earlier findings, ATs were generally underestimated, the more so the longer the actual AT. Results revealed that vehicle size affected judgments in particular for the larger actual ATs (2 and 3s), with double-sized vehicles then being judged as arriving earlier than normal-sized vehicles. Vehicle type, on the other hand, affected judgments at the smaller actual ATs (1 and 2s), with cars then being judged as arriving earlier than motorcycles. In the behavioral task participants actively drove the simulator to cross the intersection by passing through a gap in a train of traffic. Analyses of the speed variations observed during the active intersection-crossing task revealed that the size and type of vehicles in the traffic train did not affect driving behavior in the same way as in the AT judgment task. First, effects were considerably smaller, affecting driving behavior only marginally. Second, effects were opposite to expectations based on AT judgments: driver approach speeds were smaller (rather than larger) when confronted with double-sized vehicles as compared to their normal-sized counterparts and when confronted with cars as compared to motorcycles. Finally, the temporality of the effects was different on the two tasks: vehicle size affected driver approach speed in the final stages of approach rather than early on, while vehicle type affected driver approach speed early on rather than later. Overall, we conclude that the active control of approach to the intersection is not based on successive judgments of traffic vehicle arrival times. These results thereby question the

  19. Electric vehicle test report Cutler-Hammer Corvette

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Vehicles were characterized for the state of the art assessment of electric vehicles. The vehicle evaluated was a Chevrolet Corvette converted to electric operation. The original internal combustion engine was replaced by an electric traction motor. Eighteen batteries supplied the electrical energy. A controller, an onboard battery charger, and several dashboard instruments completed the conversion. The emphasis was on the electrical portion of the drive train, although some analysis and discussion of the mechanical elements are included. Tests were conducted both on the road (actually a mile long runway) and in a chassis dynamometer equipped laboratory. The majority of the tests performed were according to SAE Procedure J227a and included maximum effort accelerations, constant speed range, and cyclic range. Some tests that are not a part of the SAE Procedure J227a are described and the analysis of the data from all tests is discussed.

  20. Vehicle capture system

    NASA Astrophysics Data System (ADS)

    Tacke, Kenneth L.

    1998-12-01

    Primex Aerospace Company, under contract with the U.S. Army Armament Research Development & Engineering Center (ARDEC), has developed a portable vehicle capture system for use at vehicle checkpoints. Currently when a vehicle does not stop at a checkpoint, there are three possible reactions: let the vehicle go unchallenged, pursue the vehicle or stop the vehicle with lethal force. This system provides a non-lethal alternative that will stop and contain the vehicle. The system is completely portable with the heaviest component weighing less than 120 pounds. It can be installed with no external electrical power or permanent anchors required. In its standby mode, the system does not impede normal traffic, but on command erects a barrier in less than 1.5 seconds. System tests have been conducted using 5,100 and 8.400 pound vehicles, traveling at speeds up to 45 mph. The system is designed to minimize vehicle damage and occupant injury, typically resulting in deceleration forces of less than 2.5 gs on the vehicle. According to the drivers involved in tests at 45 mph, the stopping forces feel similar to a panic stop with the vehicle brakes locked. The system is completely reusable and be rapidly reset.

  1. Vehicle longitudinal velocity estimation during the braking process using unknown input Kalman filter

    NASA Astrophysics Data System (ADS)

    Moaveni, Bijan; Khosravi Roqaye Abad, Mahdi; Nasiri, Sayyad

    2015-10-01

    In this paper, vehicle longitudinal velocity during the braking process is estimated by measuring the wheels speed. Here, a new algorithm based on the unknown input Kalman filter is developed to estimate the vehicle longitudinal velocity with a minimum mean square error and without using the value of braking torque in the estimation procedure. The stability and convergence of the filter are analysed and proved. Effectiveness of the method is shown by designing a real experiment and comparing the estimation result with actual longitudinal velocity computing from a three-axis accelerometer output.

  2. Differences between vehicle lateral displacement on the road and in a fixed-base simulator.

    PubMed

    Blana, Evi; Golias, John

    2002-01-01

    This work investigates differences in lateral displacement when driving on curved and straight road sections in real-road and simulator conditions. We observed 100 licensed drivers on a rural road and 100 in a fixed-base simulator. Speed and lateral position on the real road were measured using videocameras. The analysis indicates that the mean vehicle lateral displacement is in general higher on the real road than in the simulator. However, these differences decrease for higher speeds at curved sections and for lower speeds at straight sections. It was also found that the standard deviation of the vehicle lateral displacement is significantly lower on the real road than the corresponding values in the simulator, at either curved or straight sections. Actual or potential applications of this research are related to a more realistic assessment of driving behavior scenarios derived on the basis of simulation experiment results.

  3. An ultrasonic sensor system based on a two-dimensional state method for highway vehicle violation detection applications.

    PubMed

    Liu, Jun; Han, Jiuqiang; Lv, Hongqiang; Li, Bing

    2015-04-16

    With the continuing growth of highway construction and vehicle use expansion all over the world, highway vehicle traffic rule violation (TRV) detection has become more and more important so as to avoid traffic accidents and injuries in intelligent transportation systems (ITS) and vehicular ad hoc networks (VANETs). Since very few works have contributed to solve the TRV detection problem by moving vehicle measurements and surveillance devices, this paper develops a novel parallel ultrasonic sensor system that can be used to identify the TRV behavior of a host vehicle in real-time. Then a two-dimensional state method is proposed, utilizing the spacial state and time sequential states from the data of two parallel ultrasonic sensors to detect and count the highway vehicle violations. Finally, the theoretical TRV identification probability is analyzed, and actual experiments are conducted on different highway segments with various driving speeds, which indicates that the identification accuracy of the proposed method can reach about 90.97%.

  4. Safety of high speed magnetic levitation transportation systems. Magnetic field testing of the TR07 Maglev vehicle and system. Volume 1: Analysis

    NASA Astrophysics Data System (ADS)

    Dietrich, Fred; Feero, William E.

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic field (EMF) emissions, both steady (dc) and produced by alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposure to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Analysis summarizes the experimental findings and compares results to common home, work, and power lines emissions for selected spectral bands.

  5. Safety of high speed magnetic levitation transportation systems. Magnetic field testing of the TR07 Maglev vehicle and system. Volume 2: Appendices

    NASA Astrophysics Data System (ADS)

    Dietrich, Fred; Robertson, David; Steiner, George

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) emissions, both steady (dc) and produced by alternating current (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposures to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Appendices include catalogs and documents detailing magnetic field data files and their specifics (static fields, spectral waveforms, and temporal and spatial information) by location.

  6. An Experimental Study of Launch Vehicle Propellant Tank Fragmentation

    NASA Technical Reports Server (NTRS)

    Richardson, Erin; Jackson, Austin; Hays, Michael; Bangham, Mike; Blackwood, James; Skinner, Troy; Richman, Ben

    2014-01-01

    In order to better understand launch vehicle abort environments, Bangham Engineering Inc. (BEi) built a test assembly that fails sample materials (steel and aluminum plates of various alloys and thicknesses) under quasi-realistic vehicle failure conditions. Samples are exposed to pressures similar to those expected in vehicle failure scenarios and filmed at high speed to increase understanding of complex fracture mechanics. After failure, the fragments of each test sample are collected, catalogued and reconstructed for further study. Post-test analysis shows that aluminum samples consistently produce fewer fragments than steel samples of similar thickness and at similar failure pressures. Video analysis shows that there are several failure 'patterns' that can be observed for all test samples based on configuration. Fragment velocities are also measured from high speed video data. Sample thickness and material are analyzed for trends in failure pressure. Testing is also done with cryogenic and noncryogenic liquid loading on the samples. It is determined that liquid loading and cryogenic temperatures can decrease material fragmentation for sub-flight thicknesses. A method is developed for capture and collection of fragments that is greater than 97 percent effective in recovering sample mass, addressing the generation of tiny fragments. Currently, samples tested do not match actual launch vehicle propellant tank material thicknesses because of size constraints on test assembly, but test findings are used to inform the design and build of another, larger test assembly with the purpose of testing actual vehicle flight materials that include structural components such as iso-grid and friction stir welds.

  7. Rapid road repair vehicle

    DOEpatents

    Mara, Leo M.

    1999-01-01

    Disclosed are improvments to a rapid road repair vehicle comprising an improved cleaning device arrangement, two dispensing arrays for filling defects more rapidly and efficiently, an array of pre-heaters to heat the road way surface in order to help the repair material better bond to the repaired surface, a means for detecting, measuring, and computing the number, location and volume of each of the detected surface imperfection, and a computer means schema for controlling the operation of the plurality of vehicle subsystems. The improved vehicle is, therefore, better able to perform its intended function of filling surface imperfections while moving over those surfaces at near normal traffic speeds.

  8. 32 CFR 263.6 - Speeding or reckless driving.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Speeding or reckless driving. 263.6 Section 263... driving. (a) No person shall drive a motor vehicle on the site at a speed greater than or in a manner... another speed limit has been duly posted, and no person shall drive a motor vehicle on the site in...

  9. 32 CFR 263.6 - Speeding or reckless driving.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Speeding or reckless driving. 263.6 Section 263... driving. (a) No person shall drive a motor vehicle on the site at a speed greater than or in a manner... another speed limit has been duly posted, and no person shall drive a motor vehicle on the site in...

  10. 32 CFR 263.6 - Speeding or reckless driving.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Speeding or reckless driving. 263.6 Section 263... driving. (a) No person shall drive a motor vehicle on the site at a speed greater than or in a manner... another speed limit has been duly posted, and no person shall drive a motor vehicle on the site in...

  11. 32 CFR 263.6 - Speeding or reckless driving.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Speeding or reckless driving. 263.6 Section 263... driving. (a) No person shall drive a motor vehicle on the site at a speed greater than or in a manner... another speed limit has been duly posted, and no person shall drive a motor vehicle on the site in...

  12. 32 CFR 263.6 - Speeding or reckless driving.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Speeding or reckless driving. 263.6 Section 263... driving. (a) No person shall drive a motor vehicle on the site at a speed greater than or in a manner... another speed limit has been duly posted, and no person shall drive a motor vehicle on the site in...

  13. City motor vehicle management system based on RFID

    NASA Astrophysics Data System (ADS)

    Yi, Zheng-jiang; Liu, San-jun

    2013-03-01

    Aiming at the shortcomings of the traditional vehicle management, a new motor vehicle management solutions is provided. The system manage the vehicles using the radio frequency long-range identification based on RFID technology.The system can identify the vehicles in 12 meters with a maximum speed of 100km/h and provides a new solution for the city motor vehicle management.

  14. Reading Speed as a Constraint of Accuracy of Self-Perception of Reading Skill

    ERIC Educational Resources Information Center

    Kwon, Heekyung; Linderholm, Tracy

    2015-01-01

    We hypothesised that college students take reading speed into consideration when evaluating their own reading skill, even if reading speed does not reliably predict actual reading skill. To test this hypothesis, we measured self-perception of reading skill, self-perception of reading speed, actual reading skill and actual reading speed to…

  15. High Speed Vortex Flows

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Wilcox, Floyd J., Jr.; Bauer, Steven X. S.; Allen, Jerry M.

    2000-01-01

    A review of the research conducted at the National Aeronautics and Space Administration (NASA), Langley Research Center (LaRC) into high-speed vortex flows during the 1970s, 1980s, and 1990s is presented. The data reviewed is for flat plates, cavities, bodies, missiles, wings, and aircraft. These data are presented and discussed relative to the design of future vehicles. Also presented is a brief historical review of the extensive body of high-speed vortex flow research from the 1940s to the present in order to provide perspective of the NASA LaRC's high-speed research results. Data are presented which show the types of vortex structures which occur at supersonic speeds and the impact of these flow structures to vehicle performance and control is discussed. The data presented shows the presence of both small- and large scale vortex structures for a variety of vehicles, from missiles to transports. For cavities, the data show very complex multiple vortex structures exist at all combinations of cavity depth to length ratios and Mach number. The data for missiles show the existence of very strong interference effects between body and/or fin vortices and the downstream fins. It was shown that these vortex flow interference effects could be both positive and negative. Data are shown which highlights the effect that leading-edge sweep, leading-edge bluntness, wing thickness, location of maximum thickness, and camber has on the aerodynamics of and flow over delta wings. The observed flow fields for delta wings (i.e. separation bubble, classical vortex, vortex with shock, etc.) are discussed in the context of' aircraft design. And data have been shown that indicate that aerodynamic performance improvements are available by considering vortex flows as a primary design feature. Finally a discussing of a design approach for wings which utilize vortex flows for improved aerodynamic performance at supersonic speed is presented.

  16. On-board emission measurement of high-loaded light-duty vehicles in Algeria.

    PubMed

    Boughedaoui, Ménouèr; Kerbachi, Rabah; Joumard, Robert

    2008-01-01

    A sample of eight private gasoline and diesel conventional light-duty vehicles (LDVs) in use with various ages, carrying a load of 460 kg, were tested on a representative trip in the traffic flow of the city of Blida to obtain emission factors representing the actual use conditions of Algerian LDVs. The gas sampling system (mini-constant volume sampling) as well as the analyzers are carried on-board the vehicle. Around 55 tests were conducted during 3 months covering more than 480 km under various real driving conditions. The mean speed downtown is about 16.1 km/hr with a rather low acceleration, an average of 0.60 m/sec2. For each test, kinematics are recorded as well as the analysis of the four emitted pollutants carbon dioxide, carbon monoxide, oxides of nitrogen, and total hydrocarbons. Emission factors were evaluated according to speed for each category of gasoline and diesel engines. The influence of some parameters such as cold/hot start, age of vehicle and its state of maintenance are discussed. Results are compared with the European database ARTEMIS for comparable vehicles. These measurements contribute to the development of unit emission of the vehicles used in Algeria, which are necessary for the calculation of emission inventory of pollutants and greenhouse gases from the road transportation sector. The unit emissions constitute a tool of decisionmaking aid regarding the conception of new regulations of vehicle control and inspection in Algeria and even in similar developing countries.

  17. Systems Challenges for Hypersonic Vehicles

    NASA Technical Reports Server (NTRS)

    Hunt, James L.; Laruelle, Gerard; Wagner, Alain

    1997-01-01

    This paper examines the system challenges posed by fully reusable hypersonic cruise airplanes and access to space vehicles. Hydrocarbon and hydrogen fueled airplanes are considered with cruise speeds of Mach 5 and 10, respectively. The access to space matrix is examined. Airbreathing and rocket powered, single- and two-stage vehicles are considered. Reference vehicle architectures are presented. Major systems/subsystems challenges are described. Advanced, enhancing systems concepts as well as common system technologies are discussed.

  18. Vehicle/guideway interaction and ride comfort in maglev systems

    SciTech Connect

    Cai, Y.; Chen, S.S.; Rote, D.M.; Coffey, H.T.

    1993-10-01

    The importance of vehicle/guideway dynamics in maglev systems is discussed. The particular interest associated with modeling vehicle guide-way interactions and explaining response characteristics of maglev systems for a multicar, multiload vehicle traversing on a single- or double-span flexible guideway are considered, with an emphasis on vehicle/guideway coupling effects, comparison of concentrated and distributed loads, and ride comfort. Coupled effects of vehicle/guideway interactions over a wide range of vehicle speeds with various vehicle and guideway parameters are investigated, and appropriate critical vehicle speeds or crossing frequencies are identified.

  19. Batteries for Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Conover, R. A.

    1985-01-01

    Report summarizes results of test on "near-term" electrochemical batteries - (batteries approaching commercial production). Nickel/iron, nickel/zinc, and advanced lead/acid batteries included in tests and compared with conventional lead/acid batteries. Batteries operated in electric vehicles at constant speed and repetitive schedule of accerlerating, coasting, and braking.

  20. Do Speed Cameras Reduce Collisions?

    PubMed Central

    Skubic, Jeffrey; Johnson, Steven B.; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

    2013-01-01

    We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods – before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not independently affect the incidence of motor vehicle collisions. PMID:24406979

  1. 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

  2. Calculating Speed of Sound

    NASA Astrophysics Data System (ADS)

    Bhatnagar, Shalabh

    2017-01-01

    Sound is an emerging source of renewable energy but it has some limitations. The main limitation is, the amount of energy that can be extracted from sound is very less and that is because of the velocity of the sound. The velocity of sound changes as per medium. If we could increase the velocity of the sound in a medium we would be probably able to extract more amount of energy from sound and will be able to transfer it at a higher rate. To increase the velocity of sound we should know the speed of sound. If we go by the theory of classic mechanics speed is the distance travelled by a particle divided by time whereas velocity is the displacement of particle divided by time. The speed of sound in dry air at 20 °C (68 °F) is considered to be 343.2 meters per second and it won't be wrong in saying that 342.2 meters is the velocity of sound not the speed as it's the displacement of the sound not the total distance sound wave covered. Sound travels in the form of mechanical wave, so while calculating the speed of sound the whole path of wave should be considered not just the distance traveled by sound. In this paper I would like to focus on calculating the actual speed of sound wave which can help us to extract more energy and make sound travel with faster velocity.

  3. Rapid road repair vehicle

    DOEpatents

    Mara, Leo M.

    1998-01-01

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find an the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was was heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past.

  4. Rapid road repair vehicle

    DOEpatents

    Mara, L.M.

    1998-05-05

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find at the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was not heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past. 2 figs.

  5. Preliminary aerothermodynamic design method for hypersonic vehicles

    NASA Technical Reports Server (NTRS)

    Harloff, G. J.; Petrie, S. L.

    1987-01-01

    Preliminary design methods are presented for vehicle aerothermodynamics. Predictions are made for Shuttle orbiter, a Mach 6 transport vehicle and a high-speed missile configuration. Rapid and accurate methods are discussed for obtaining aerodynamic coefficients and heat transfer rates for laminar and turbulent flows for vehicles at high angles of attack and hypersonic Mach numbers.

  6. 43 CFR 8365.1-3 - Vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Vehicles. 8365.1-3 Section 8365.1-3 Public... OF THE INTERIOR RECREATION PROGRAMS VISITOR SERVICES Rules of Conduct § 8365.1-3 Vehicles. (a) When operating a vehicle on the public lands, no person shall exceed posted speed limits, willfully...

  7. 43 CFR 8365.1-3 - Vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Vehicles. 8365.1-3 Section 8365.1-3 Public... OF THE INTERIOR RECREATION PROGRAMS VISITOR SERVICES Rules of Conduct § 8365.1-3 Vehicles. (a) When operating a vehicle on the public lands, no person shall exceed posted speed limits, willfully...

  8. 43 CFR 8365.1-3 - Vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Vehicles. 8365.1-3 Section 8365.1-3 Public... OF THE INTERIOR RECREATION PROGRAMS VISITOR SERVICES Rules of Conduct § 8365.1-3 Vehicles. (a) When operating a vehicle on the public lands, no person shall exceed posted speed limits, willfully...

  9. 43 CFR 8365.1-3 - Vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Vehicles. 8365.1-3 Section 8365.1-3 Public... OF THE INTERIOR RECREATION PROGRAMS VISITOR SERVICES Rules of Conduct § 8365.1-3 Vehicles. (a) When operating a vehicle on the public lands, no person shall exceed posted speed limits, willfully...

  10. Vehicle transmission with forward and reverse speeds

    SciTech Connect

    Keenan, T.F.; Kass, J.J.

    1986-05-20

    A low profile transmission is described comprising: a casing having forward, rear and side walls, the rear wall containing ports, an output shaft rotatably mounted in the forward and rear walls of the casing carrying a first and second gear fixably mounted to the output shaft, and a spiral pinion fixably mounted to the end of the output shaft extending forward of the forward wall communicating with the steering drive mechanism; a first gear shaft rotatably mounted in the forward and rear wall off the casing carrying a third gear fixably mounted to the first gear shaft in constant mesh with the first gear, a plurality of fourth gears rotatably mounted to the first gear shaft, first clutching means for selectively coupling one of the fourth gears to the first gear shaft; a second gear shaft rotatably mounted in the forward and rear wall of the casing carrying a fifth gear fixably mounted to the second gear shaft and in constant mesh with the second gear; sixth gears rotatably mounted to the second gear shaft; second clutching means for selectively coupling one of sixth gears to the second gear shaft.

  11. Intravehicular, Short- and Long-Range Communication Information Fusion for Providing Safe Speed Warnings

    PubMed Central

    Jiménez, Felipe; Naranjo, Jose Eugenio; Serradilla, Francisco; Pérez, Elisa; Hernández, María Jose; Ruiz, Trinidad; Anaya, José Javier; Díaz, Alberto

    2016-01-01

    Inappropriate speed is a relevant concurrent factor in many traffic accidents. Moreover, in recent years, traffic accidents numbers in Spain have fallen sharply, but this reduction has not been so significant on single carriageway roads. These infrastructures have less equipment than high-capacity roads, therefore measures to reduce accidents on them should be implemented in vehicles. This article describes the development and analysis of the impact on the driver of a warning system for the safe speed on each road section in terms of geometry, the presence of traffic jams, weather conditions, type of vehicle and actual driving conditions. This system is based on an application for smartphones and includes knowledge of the vehicle position via Ground Positioning System (GPS), access to intravehicular information from onboard sensors through the Controller Area Network (CAN) bus, vehicle data entry by the driver, access to roadside information (short-range communications) and access to a centralized server with information about the road in the current and following sections of the route (long-range communications). Using this information, the system calculates the safe speed, recommends the appropriate speed in advance in the following sections and provides warnings to the driver. Finally, data are sent from vehicles to a server to generate new information to disseminate to other users or to supervise drivers’ behaviour. Tests in a driving simulator have been used to define the system warnings and Human Machine Interface (HMI) and final tests have been performed on real roads in order to analyze the effect of the system on driver behavior. PMID:26805839

  12. The impact of speed and other variables on pedestrian safety in Maine.

    PubMed

    Gårder, Per E

    2004-07-01

    The aim of this paper is to analyze pedestrian crashes with an emphasis on how actual travel speeds and characteristics of the locations influence crash numbers. Statewide data from Maine was analyzed. Descriptive crash and behavioral statistics are presented in the paper. Pedestrian and vehicle volumes were gathered for 122 locations in varying environments throughout Maine and crash numbers were predicted and compared to outcomes. Prediction models from Sweden and the UK were used since US models are nonexistant. It was found that high speeds and wide roads lead to more crashes and that the focus of safety improvement should be on arterials and major collectors. A strong relationship was also found between crash severity and speed.

  13. Electric vehicle drive train with rollback detection and compensation

    DOEpatents

    Konrad, C.E.

    1994-12-27

    An electric vehicle drive train includes a controller for detecting and compensating for vehicle rollback, as when the vehicle is started upward on an incline. The vehicle includes an electric motor rotatable in opposite directions corresponding to opposite directions of vehicle movement. A gear selector permits the driver to select an intended or desired direction of vehicle movement. If a speed and rotational sensor associated with the motor indicates vehicle movement opposite to the intended direction of vehicle movement, the motor is driven to a torque output magnitude as a nonconstant function of the rollback speed to counteract the vehicle rollback. The torque function may be either a linear function of speed or a function of the speed squared. 6 figures.

  14. Electric vehicle drive train with rollback detection and compensation

    DOEpatents

    Konrad, Charles E.

    1994-01-01

    An electric vehicle drive train includes a controller for detecting and compensating for vehicle rollback, as when the vehicle is started upward on an incline. The vehicle includes an electric motor rotatable in opposite directions corresponding to opposite directions of vehicle movement. A gear selector permits the driver to select an intended or desired direction of vehicle movement. If a speed and rotational sensor associated with the motor indicates vehicle movement opposite to the intended direction of vehicle movement, the motor is driven to a torque output magnitude as a nonconstant function of the rollback speed to counteract the vehicle rollback. The torque function may be either a linear function of speed or a function of the speed squared.

  15. 32 CFR 636.22 - Speed regulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION (SPECIFIC INSTALLATIONS) Fort Stewart, Georgia § 636.22 Speed.... (iii) The flashing, yellow, caution lights are in operation. (3) Fort Stewart housing areas, 20...

  16. 36 CFR 4.3 - Authorized emergency vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Authorized emergency vehicles... INTERIOR VEHICLES AND TRAFFIC SAFETY § 4.3 Authorized emergency vehicles. (a) The operator of an authorized emergency vehicle, when responding to an emergency or when pursuing or apprehending an actual or...

  17. 36 CFR 4.3 - Authorized emergency vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Authorized emergency vehicles... INTERIOR VEHICLES AND TRAFFIC SAFETY § 4.3 Authorized emergency vehicles. (a) The operator of an authorized emergency vehicle, when responding to an emergency or when pursuing or apprehending an actual or...

  18. 36 CFR 4.3 - Authorized emergency vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Authorized emergency vehicles... INTERIOR VEHICLES AND TRAFFIC SAFETY § 4.3 Authorized emergency vehicles. (a) The operator of an authorized emergency vehicle, when responding to an emergency or when pursuing or apprehending an actual or...

  19. 36 CFR 4.3 - Authorized emergency vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Authorized emergency vehicles... INTERIOR VEHICLES AND TRAFFIC SAFETY § 4.3 Authorized emergency vehicles. (a) The operator of an authorized emergency vehicle, when responding to an emergency or when pursuing or apprehending an actual or...

  20. Improved road traffic emission inventories by adding mean speed distributions

    NASA Astrophysics Data System (ADS)

    Smit, Robin; Poelman, Muriel; Schrijver, Jeroen

    Does consideration of average speed distributions on roads—as compared to single mean speed—lead to different results in emission modelling of large road networks? To address this question, a post-processing method is developed to predict mean speed distributions using available traffic data from a dynamic macroscopic traffic model (Indy) that was run for an actual test network (Amsterdam). Two emission models are compared: a continuous (COPERT IV) and a discrete model (VERSIT+ macro). Computations show that total network emissions of CO, HC, NO x, PM 10 and CO 2 are generally (but not always) increased after application of the mean speed distribution method up to +9%, and even up to +24% at sub-network level (urban, rural, motorway). Conventional computation methods thus appear to produce biased results (underestimation). The magnitude and direction of the effect is a function of emission model (type), shape of the composite emission factor curve and change in the joint distribution of (sub)-network VKT (vehicle kilometres travelled) and speed. Differences between the two emission models in predicted total network emissions are generally larger, which indicates that other issues (e.g., emission model validation, model choice) are more relevant.

  1. Electric Vehicles at Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Chesson, Bruce E.

    2007-01-01

    The story of how the transportation office began by introducing low speed electric cars (LSEV) to the fleet managers and employees. This sparked and interest in purchasing some of these LSEV and the usage on KSC. Transportation was approached by a vender of High Speed Electric Vehicle (HSEV) we decided to test the HSEV to see if they would meet our fleet vehicle needs. Transportation wrote a Space Act Agreement (SAA) for the loan of three Lithium Powered Electric vehicles for a one year test. The vehicles have worked very well and we have extended the test for another year. The use of HSEV has pushed for an independent Electric Vehicle Study to be performed to consider ways to effectively optimize the use of electric vehicles in replacement of gasoline vehicles in the KSC vehicle fleet. This will help the center to move closer to meeting the Executive Order 13423.

  2. Motor vehicle drivers' injuries in train-motor vehicle crashes.

    PubMed

    Zhao, Shanshan; Khattak, Aemal

    2015-01-01

    The objectives of this research were to: (1) identify a more suitable model for modeling injury severity of motor vehicle drivers involved in train-motor vehicle crashes at highway-rail grade crossings from among three commonly used injury severity models and (2) to investigate factors associated with injury severity levels of motor vehicle drivers involved in train-motor vehicle crashes at such crossings. The 2009-2013 highway-rail grade crossing crash data and the national highway-rail crossing inventory data were combined to produce the analysis dataset. Four-year (2009-2012) data were used for model estimation while 2013 data were used for model validation. The three injury severity levels-fatal, injury and no injury-were based on the reported intensity of motor-vehicle drivers' injuries at highway-rail grade crossings. The three injury severity models evaluated were: ordered probit, multinomial logit and random parameter logit. A comparison of the three models based on different criteria showed that the random parameter logit model and multinomial logit model were more suitable for injury severity analysis of motor vehicle drivers involved in crashes at highway-rail grade crossings. Some of the factors that increased the likelihood of more severe crashes included higher train and vehicle speeds, freight trains, older drivers, and female drivers. Where feasible, reducing train and motor vehicle speeds and nighttime lighting may help reduce injury severities of motor vehicle drivers.

  3. Linguistic Theory and Actual Language.

    ERIC Educational Resources Information Center

    Segerdahl, Par

    1995-01-01

    Examines Noam Chomsky's (1957) discussion of "grammaticalness" and the role of linguistics in the "correct" way of speaking and writing. It is argued that the concern of linguistics with the tools of grammar has resulted in confusion, with the tools becoming mixed up with the actual language, thereby becoming the central…

  4. Launch of a Vehicle from a Ramp

    ERIC Educational Resources Information Center

    Cross, Rod

    2011-01-01

    A vehicle proceeding up an inclined ramp will become airborne if the ramp comes to a sudden end and if the vehicle fails to stop before it reaches the end of the ramp. A vehicle may also become airborne if it passes over the top of a hill at sufficient speed. In both cases, the vehicle becomes airborne if the point of support underneath the…

  5. Performance of an Automated-Mixed-Traffic-Vehicle /AMTV/ System. [urban people mover

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

    This study analyzes the operation and evaluates the expected performance of a proposed automatic guideway transit system which uses low-speed Automated Mixed Traffic Vehicles (AMTV's). Vehicle scheduling and headway control policies are evaluated with a transit system simulation model. The effect of mixed-traffic interference on the average vehicle speed is examined with a vehicle-pedestrian interface model. Control parameters regulating vehicle speed are evaluated for safe stopping and passenger comfort.

  6. Estimating the ride quality characteristics of vehicles with random decrement analysis of on-the-road vibration response data

    NASA Astrophysics Data System (ADS)

    Ainalis, Daniel; Rouillard, Vincent; Sek, Michael

    2016-06-01

    This paper describes the application of a practical analytical technique based on the random decrement method to estimate the rigid sprung mass dynamic characteristics (frequency response function) of road vehicles using only vibration response data during constant-speed operation. A brief history and development of the random decrement technique is presented, along with a summary of work undertaken on optimal parameter selection to establish the random decrement signature. Two approaches to estimate the dynamic characteristics from the random decrement signature are described and evaluated. A custom, single-wheeled vehicle (physical quarter car) was commissioned to undertake a series of on-the-road experiments at various nominally constant operating speeds. The vehicle, also instrumented as an inertial profilometer, simultaneously measured the longitudinal pavement profile to establish the vehicle's actual dynamic characteristics during operation. The main outcome of the paper is that the random decrement technique can be used to provide accurate estimates of the sprung mass mode of the vehicle's dynamic characteristics for both linear and nonlinear suspension systems of an idealised vehicle.

  7. Preventing passenger vehicle occupant injuries by vehicle design--a historical perspective from IIHS.

    PubMed

    O'Neill, Brian

    2009-04-01

    Motor vehicle crashes result in some 1.2 million deaths and many more injuries worldwide each year and is one of the biggest public health problems facing societies today. This article reviews the history of, and future potential for, one important countermeasure-designing vehicles that reduce occupant deaths and injuries. For many years, people had urged automakers to add design features to reduce crash injuries, but it was not until the mid-1960s that the idea of pursuing vehicle countermeasures gained any significant momentum. In 1966, the U.S. Congress passed the National Traffic and Motor Vehicle Safety Act, requiring the government to issue a comprehensive set of vehicle safety standards. This was the first broad set of requirements issued anywhere in the world, and within a few years similar standards were adopted in Europe and Australia. Early vehicle safety standards specified a variety of safety designs resulting in cars being equipped with lap/shoulder belts, energy-absorbing steering columns, crash-resistant door locks, high-penetration-resistant windshields, etc. Later, the standards moved away from specifying particular design approaches and instead used crash tests and instrumented dummies to set limits on the potential for serious occupant injuries by crash mode. These newer standards paved the way for an approach that used the marketplace, in addition to government regulation, to improve vehicle safety designs-using crash tests and instrumented dummies to provide consumers with comparative safety ratings for new vehicles. The approach began in the late 1970s, when NHTSA started publishing injury measures from belted dummies in new passenger vehicles subjected to frontal barrier crash tests at speeds somewhat higher than specified in the corresponding regulation. This program became the world's first New Car Assessment Program (NCAP) and rated frontal crashworthiness by awarding stars (five stars being the best and one the worst) derived from head

  8. Vehicle test report: Electric Vehicle Associates electric conversion of an AMC Pacer

    NASA Technical Reports Server (NTRS)

    Price, T. W.; Wirth, V. A., Jr.; Pompa, M. F.

    1981-01-01

    Tests were performed to characterize certain parameters of the EVA Pacer and to provide baseline data that can be used for the comparison of improved batteries that may be incorporated into the vehicle at a later time. The vehicle tests were concentrated on the electrical drive subsystem; i.e., the batteries, controller and motor. The tests included coastdowns to characterize the road load, and range evaluations for both cyclic and constant speed conditions. A qualitative evaluation of the vehicle's performance was made by comparing its constant speed range performance with other electric and hybrid vehicles. The Pacer performance was approximately equal to the majority of those vehicles assessed in 1977.

  9. Efficient Low-Speed Flight in a Wind Field

    NASA Technical Reports Server (NTRS)

    Feldman, Michael A.

    1996-01-01

    A new software tool was needed for flight planning of a high altitude, low speed unmanned aerial vehicle which would be flying in winds close to the actual airspeed of the vehicle. An energy modeled NLP (non-linear programming) formulation was used to obtain results for a variety of missions and wind profiles. The energy constraint derived included terms due to the wind field and the performance index was a weighted combination of the amount of fuel used and the final time. With no emphasis on time and with no winds the vehicle was found to fly at maximum lift to drag velocity, V(sub md). When flying in tail winds the velocity was less than V(sub md), while flying in head winds the velocity was higher than V(sub md). A family of solutions was found with varying times of flight and varying fuel amounts consumed which will aid the operator in choosing a flight plan depending on a desired landing time. At certain parts of the flight, the turning terms in the energy constraint equation were found to be significant. An analysis of a simpler vertical plane cruise optimal control problem was used to explain some of the characteristics of the vertical plane NLP results.

  10. Electric Vehicle Power Controller.

    DTIC Science & Technology

    1981-12-01

    combustion engine are coupled in parallel to the drive train, as shown in Figure 2. In this configuration the speed of a series DC motor is governed by the...internal Hyrine Drive Train Fig. 2. Parallel Hybrid Vehicle Block Diagram (Ref. 2) 12 combustion engine is coupled to the drive shaft of the DC motor by a...V- belt and electric clutch assembly. The engine is manually engaged during high speed cruising to reduce the current demand of the DC motor (Ref. 3

  11. Effects of average speed enforcement on speed compliance and crashes: a review of the literature.

    PubMed

    Soole, David W; Watson, Barry C; Fleiter, Judy J

    2013-05-01

    Average speed enforcement is a relatively new approach gaining popularity throughout Europe and Australia. This paper reviews the evidence regarding the impact of this approach on vehicle speeds, crash rates and a number of additional road safety and public health outcomes. The economic and practical viability of the approach as a road safety countermeasure is also explored. A literature review, with an international scope, of both published and grey literature was conducted. There is a growing body of evidence to suggest a number of road safety benefits associated with average speed enforcement, including high rates of compliance with speed limits, reductions in average and 85th percentile speeds and reduced speed variability between vehicles. Moreover, the approach has been demonstrated to be particularly effective in reducing excessive speeding behaviour. Reductions in crash rates have also been reported in association with average speed enforcement, particularly in relation to fatal and serious injury crashes. In addition, the approach has been shown to improve traffic flow, reduce vehicle emissions and has also been associated with high levels of public acceptance. Average speed enforcement offers a greater network-wide approach to managing speeds that reduces the impact of time and distance halo effects associated with other automated speed enforcement approaches. Although comparatively expensive it represents a highly reliable approach to speed enforcement that produces considerable returns on investment through reduced social and economic costs associated with crashes.

  12. A hybrid positioning strategy for vehicles in a tunnel based on RFID and in-vehicle sensors.

    PubMed

    Song, Xiang; Li, Xu; Tang, Wencheng; Zhang, Weigong; Li, Bin

    2014-12-05

    Many intelligent transportation system applications require accurate, reliable, and continuous vehicle positioning. How to achieve such positioning performance in extended GPS-denied environments such as tunnels is the main challenge for land vehicles. This paper proposes a hybrid multi-sensor fusion strategy for vehicle positioning in tunnels. First, the preliminary positioning algorithm is developed. The Radio Frequency Identification (RFID) technology is introduced to achieve preliminary positioning in the tunnel. The received signal strength (RSS) is used as an indicator to calculate the distances between the RFID tags and reader, and then a Least Mean Square (LMS) federated filter is designed to provide the preliminary position information for subsequent global fusion. Further, to improve the positioning performance in the tunnel, an interactive multiple model (IMM)-based global fusion algorithm is developed to fuse the data from preliminary positioning results and low-cost in-vehicle sensors, such as electronic compasses and wheel speed sensors. In the actual implementation of IMM, the strong tracking extended Kalman filter (STEKF) algorithm is designed to replace the conventional extended Kalman filter (EKF) to achieve model individual filtering. Finally, the proposed strategy is evaluated through experiments. The results validate the feasibility and effectiveness of the proposed strategy.

  13. A Hybrid Positioning Strategy for Vehicles in a Tunnel Based on RFID and In-Vehicle Sensors

    PubMed Central

    Song, Xiang; Li, Xu; Tang, Wencheng; Zhang, Weigong; Li, Bin

    2014-01-01

    Many intelligent transportation system applications require accurate, reliable, and continuous vehicle positioning. How to achieve such positioning performance in extended GPS-denied environments such as tunnels is the main challenge for land vehicles. This paper proposes a hybrid multi-sensor fusion strategy for vehicle positioning in tunnels. First, the preliminary positioning algorithm is developed. The Radio Frequency Identification (RFID) technology is introduced to achieve preliminary positioning in the tunnel. The received signal strength (RSS) is used as an indicator to calculate the distances between the RFID tags and reader, and then a Least Mean Square (LMS) federated filter is designed to provide the preliminary position information for subsequent global fusion. Further, to improve the positioning performance in the tunnel, an interactive multiple model (IMM)-based global fusion algorithm is developed to fuse the data from preliminary positioning results and low-cost in-vehicle sensors, such as electronic compasses and wheel speed sensors. In the actual implementation of IMM, the strong tracking extended Kalman filter (STEKF) algorithm is designed to replace the conventional extended Kalman filter (EKF) to achieve model individual filtering. Finally, the proposed strategy is evaluated through experiments. The results validate the feasibility and effectiveness of the proposed strategy. PMID:25490581

  14. Vehicle test report: Battronic pickup truck

    NASA Technical Reports Server (NTRS)

    Price, T. W.; Shain, T. W.; Freeman, R. J.; Pompa, M. F.

    1982-01-01

    An electric pickup truck was tested to characterize certain parameters and to provide baseline data that can be used for the comparison of improved batteries that may be incorporated into the vehicle at a later time. The vehicle tests were concentrated on the electrical drive subsystem; i.e., the batteries, controller, and motor. The tests included coastdowns to characterize the road load and range evaluations for both cyclic and constant speed conditions. A qualitative evaluation of the vehicle's performance was made by comparing its constant speed range performance with other vehicles.

  15. Vehicular enginee idel speed and cruise control system

    SciTech Connect

    Kenny, A.A.; Sokalski, R.G.

    1986-02-11

    This patent describes a vehicular cruise and engine idling speed control system. This system consists of: 1.) An actuator adapted for engagement to a vehicular engine throttle that in a first engaged condition is operable upon receipt of a first control signal to move the throttle to regulate the vehicle speed. In a second engaged condition the engine throttle is operable upon receipt of a second control signal to regulate engine idling speed independent of the vehicle speed, 2.) A controller which responds to a sensed vehicle speed and an operator selected vehicle speed to provide the first and second control signal from at least one sensed engine operating condition upon establishment of the second engaged condition, 3.) An operator control for establishment of the first and second engaged conditions, 4.) A sensor throttle, actuated by the operator, is functionally effective for switching the controller output from the second control signal to the first control signal and causes the actuator to position the throttle at an advanced engine idle speed pick-up position, 5.) A device for differentiating between the operator selected vehicle speed throttle position and the regulated engine idle speed pick-up throttle position, 6.) A mechanism for insuring that the engine speed decreases in a uniform manner from the engine idle speed pick-up throttle position to the regulated engine idle speed throttle position.

  16. Automated mixed traffic vehicle control and scheduling study

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  17. Smart Vehicle System

    NASA Astrophysics Data System (ADS)

    Pahadiya, Pallavi; Gupta, Rajni

    2010-11-01

    An approach to overcome the accidental problem happens in the night, while the driver is drunk or feels sleepy. This system controls the speed of the vehicle at steep turns. It is designed, to provide the information to the driver, whether the next turn is right/left, is there any traffic jam or land sliding in the coming way. It also assists during heavy rains and mist conditions. It may be implemented by using computer or by using a dedicated microcontroller. If we have a group of vehicles connected with the system then we can locate them by using the cameras, at different places. Information regarding any vehicle can be transmitted anywhere using Internet provided at the monitoring system, so as to prevent accidents or provide information during any calamity.

  18. Hybrid Turbine Electric Vehicle

    NASA Technical Reports Server (NTRS)

    Viterna, Larry A.

    1997-01-01

    Hybrid electric power trains may revolutionize today's ground passenger vehicles by significantly improving fuel economy and decreasing emissions. The NASA Lewis Research Center is working with industry, universities, and Government to develop and demonstrate a hybrid electric vehicle. Our partners include Bowling Green State University, the Cleveland Regional Transit Authority, Lincoln Electric Motor Division, the State of Ohio's Department of Development, and Teledyne Ryan Aeronautical. The vehicle will be a heavy class urban transit bus offering double the fuel economy of today's buses and emissions that are reduced to 1/10th of the Environmental Protection Agency's standards. At the heart of the vehicle's drive train is a natural-gas-fueled engine. Initially, a small automotive engine will be tested as a baseline. This will be followed by the introduction of an advanced gas turbine developed from an aircraft jet engine. The engine turns a high-speed generator, producing electricity. Power from both the generator and an onboard energy storage system is then provided to a variable-speed electric motor attached to the rear drive axle. An intelligent power-control system determines the most efficient operation of the engine and energy storage system.

  19. Vehicle health management technology needs

    NASA Technical Reports Server (NTRS)

    Hammond, Walter E.; Jones, W. G.

    1992-01-01

    Background material on vehicle health management (VHM) and health monitoring/control is presented. VHM benefits are described and a list of VHM technology needs that should be pursued is presented. The NASA funding process as it impacts VHM technology funding is touched upon, and the VHM architecture guidelines for generic launch vehicles are described. An example of a good VHM architecture, design, and operational philosophy as it was conceptualized for the National Launch System program is presented. Consideration is given to the Strategic Avionics Technology Working Group's role in VHM, earth-to-orbit, and space vehicle avionics technology development considerations, and some actual examples of VHM benefits for checkout are given.

  20. Aeroacoustics of Space Vehicles

    NASA Technical Reports Server (NTRS)

    Panda, Jayanta

    2014-01-01

    While for airplanes the subject of aeroacoustics is associated with community noise, for space vehicles it is associated with vibro-acoustics and structural dynamics. Surface pressure fluctuations encountered during launch and travel through lower part of the atmosphere create intense vibro-acoustics environment for the payload, electronics, navigational equipment, and a large number of subsystems. All of these components have to be designed and tested for flight-certification. This presentation will cover all three major sources encountered in manned and unmanned space vehicles: launch acoustics, ascent acoustics and abort acoustics. Launch pads employ elaborate acoustic suppression systems to mitigate the ignition pressure waves and rocket plume generated noise during the early part of the liftoff. Recently we have used large microphone arrays to identify the noise sources during liftoff and found that the standard model by Eldred and Jones (NASA SP-8072) to be grossly inadequate. As the vehicle speeds up and reaches transonic speed in relatively denser part of the atmosphere, various shock waves and flow separation events create unsteady pressure fluctuations that can lead to high vibration environment, and occasional coupling with the structural modes, which may lead to buffet. Examples of wind tunnel tests and computational simulations to optimize the outer mold line to quantify and reduce the surface pressure fluctuations will be presented. Finally, a manned space vehicle needs to be designed for crew safety during malfunctioning of the primary rocket vehicle. This brings the subject of acoustic environment during abort. For NASAs Multi-Purpose Crew Vehicle (MPCV), abort will be performed by lighting rocket motors atop the crew module. The severe aeroacoustics environments during various abort scenarios were measured for the first time by using hot helium to simulate rocket plumes in the Ames unitary plan wind tunnels. Various considerations used for the

  1. How People Actually Use Thermostats

    SciTech Connect

    Meier, Alan; Aragon, Cecilia; Hurwitz, Becky; Mujumdar, Dhawal; Peffer, Therese; Perry, Daniel; Pritoni, Marco

    2010-08-15

    Residential thermostats have been a key element in controlling heating and cooling systems for over sixty years. However, today's modern programmable thermostats (PTs) are complicated and difficult for users to understand, leading to errors in operation and wasted energy. Four separate tests of usability were conducted in preparation for a larger study. These tests included personal interviews, an on-line survey, photographing actual thermostat settings, and measurements of ability to accomplish four tasks related to effective use of a PT. The interviews revealed that many occupants used the PT as an on-off switch and most demonstrated little knowledge of how to operate it. The on-line survey found that 89% of the respondents rarely or never used the PT to set a weekday or weekend program. The photographic survey (in low income homes) found that only 30% of the PTs were actually programmed. In the usability test, we found that we could quantify the difference in usability of two PTs as measured in time to accomplish tasks. Users accomplished the tasks in consistently shorter times with the touchscreen unit than with buttons. None of these studies are representative of the entire population of users but, together, they illustrate the importance of improving user interfaces in PTs.

  2. Speed limits, enforcement, and health consequences.

    PubMed

    Elvik, Rune

    2012-04-01

    This review summarizes current knowledge regarding the effects of speed limit enforcement on public health. Speed limits are commonly used around the world to regulate the maximum speed at which motor vehicles can be operated on public roads. Speed limits are statutory, and violations of them are normally sanctioned by means of fixed penalties (traffic tickets) or, in the event of serious violations, suspension of the driver's license and imposition of prison sentences. Speed limit violations are widespread in all countries for which statistics can be found. Speeding contributes more to the risk of traffic injury than do other risk factors for which estimates of population-attributable risk are available. Traffic speed strongly influences impact speed in crashes and therefore has major implications for public health.

  3. Unmanned vehicle mobility: Limits of autonomous navigation

    NASA Astrophysics Data System (ADS)

    McCormac, A. W.; Hanna, D. M.; McFee, J.

    Considerable research is being conducted on the development of unmanned vehicles for military and civilian applications, particularly for hostile environments. It is desirable to produce a vehicle which can select its own route, not requiring remote navigation, but then it would be required to sense its surroundings. Although imaging systems and modern computers make this possible, the extreme data processing demands usually make it impractical. It is suggested that an inverse relationship exists between vehicle mobility and the complexity of the autonomous navigation system required for an unmanned vehicle. An overview of vehicle navigation is presented which shows the degree to which navigation is affected by increasing inherent mobility. If the inherent mobility of a vehicle is greatly enhanced, the scene image processing requirements and navigational computations are greatly simplified. This means the vehicle path selection and speed and steering adjustments may be made more quickly, resulting in higher vehicle speeds whenever possible. Combined with reduced deviation from the intended path, this would greatly increase the speed of the vehicle from one given point to another, suggesting that high speed autonomous navigation may be feasible.

  4. 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.

  5. Unsafe at Any (Wind) Speed?.

    NASA Astrophysics Data System (ADS)

    Schmidlin, Thomas; Hammer, Barbara; King, Paul; Ono, Yuichi; Miller, L. Scott; Thumann, Gregory

    2002-12-01

    The goal of this research was to examine the relative safety and stability of stationary motor vehicles exposed to severe winds. The focus was on private passenger vehicles. 1) The behavior of two instrumented storm-chase vehicles that were exposed to severe winds, 2) the behavior of 291 vehicles exposed to a tornado, and 3) the wind speed required to upset a sedan and a minivan exposed to winds in a wind tunnel were studied. A wind as strong as 47 m s1 (105 mph) has been measured by a storm-chase pickup truck and 44 m s1 (98 mph) by a storm chase sedan. The vehicles were not adversely affected by the wind. Also studied were 291 vehicles parked outdoors at homes struck by tornadoes, and the behavior of the vehicles was compared to the F-scale damage to the house. At sites with F1 or F2 damage, 72% of the vehicles were not moved by the wind and 96% were not tipped over. At sites with F3 or F4 damage, 50% were not moved by the wind and 82% were not tipped over. Wind tunnel tests on a sedan and minivan showed they were most vulnerable to upset (lifting of one tire from the ground) with wind directions near 45° and 135°, as measured from the front. When modeled with 5° of suspension tilt to the side, the sedan was found to be upset at wind speeds of 51-67 m s1 (115-150 mph), and the minivan was upset at wind speeds of 58-80 m s1 (130-180 mph). Although an underground shelter or sturdy building offer the best protection from severe winds, it is found that a vehicle may be a relatively stable place and may be safer than a mobile home or the outdoors. These findings may warrant changes to public recommendations made during tornado warnings and other severe storm situations.

  6. Comparison of high speed impact test of solder joints with board level drop test

    NASA Astrophysics Data System (ADS)

    Guruprasad, Pradosh

    Efforts have been made in this study to evaluate the characteristics of solder joint failure by using a new high speed impact tester. First, the dynamics and characteristics of the test vehicle in a board level drop test have been evaluated. A thorough understanding of the behavior of the test vehicle is examined by characterizing its response under different test profiles and board dimensions. This is done in an attempt to optimize the test procedure used to qualify electronic products subjected to high strain rate drop/shock environment. The effects of peak acceleration and change in velocity of the impact pulse on the reliability of the test vehicle have been studied. In situ strain measurements have been used to aid us in characterizing the board response under high strain rate loading conditions. Also finite element analysis has been used to better understand the board response under different loading conditions. Based on the experimental results and analysis, ways to improvise the drop test setup have been discussed. A more thorough understanding of the solder joint behavior is examined by characterizing the behavior with respect to varying impact profiles on a new pendulum fatigue and a high speed impact tester. This is done in an attempt to address solder joint failures in actual product that may be operating under high strain rate or shock environments and to reduce the actual test time needed for a board level drop test. Comparison between the high speed pendulum impact test and drop test was primarily made by evaluating the failure modes from these two tests. Energy absorbed by the solder in a single impact has been used to predict the reliability in a board level test.

  7. Two-speed transaxle

    DOEpatents

    Kalns, Ilmars

    1981-01-01

    Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

  8. Research on Hybrid Vehicle Drivetrain

    NASA Astrophysics Data System (ADS)

    Xie, Zhongzhi

    Hybrid cars as a solution to energy saving, emission reduction measures, have received widespread attention. Motor drive system as an important part of the hybrid vehicles as an important object of study. Based on the hybrid electric vehicle powertrain control system for permanent magnet synchronous motor as the object of study. Can be applied to hybrid car compares the characteristics of traction motors, chose permanent magnet synchronous Motors as drive motors for hybrid vehicles. Building applications in hybrid cars in MATLAB/Simulink simulation model of permanent-magnet synchronous motor speed control system and analysis of simulation results.

  9. Dazzle Camouflage Affects Speed Perception

    PubMed Central

    Scott-Samuel, Nicholas E.; Baddeley, Roland; Palmer, Chloe E.; Cuthill, Innes C.

    2011-01-01

    Movement is the enemy of camouflage: most attempts at concealment are disrupted by motion of the target. Faced with this problem, navies in both World Wars in the twentieth century painted their warships with high contrast geometric patterns: so-called “dazzle camouflage”. Rather than attempting to hide individual units, it was claimed that this patterning would disrupt the perception of their range, heading, size, shape and speed, and hence reduce losses from, in particular, torpedo attacks by submarines. Similar arguments had been advanced earlier for biological camouflage. Whilst there are good reasons to believe that most of these perceptual distortions may have occurred, there is no evidence for the last claim: changing perceived speed. Here we show that dazzle patterns can distort speed perception, and that this effect is greatest at high speeds. The effect should obtain in predators launching ballistic attacks against rapidly moving prey, or modern, low-tech battlefields where handheld weapons are fired from short ranges against moving vehicles. In the latter case, we demonstrate that in a typical situation involving an RPG7 attack on a Land Rover the reduction in perceived speed is sufficient to make the grenade miss where it was aimed by about a metre, which could be the difference between survival or not for the occupants of the vehicle. PMID:21673797

  10. Power Sources for Micro-Autonomous Vehicles- Challenges and Prospects

    NASA Technical Reports Server (NTRS)

    Narayan, S. R.; Kisor, A.; Valdez, T. I.; Manohara, H.

    2009-01-01

    Micro-autonomous vehicle systems are expected to have expanded role in military missions by providing full spectrum intelligence, surveillance and reconnaissance support on the battlefield, suppression of enemy defenses, and enabling co-operative (swarm-like) configurations. Of the numerous demanding requirements of autonomy, sensing, navigation, mobility, etc., meeting the requirement of mission duration or endurance is a very challenging one. This requirement is demanding because of the constraints of mass and volume that limit the quantity of energy that can be stored on-board. Energy is required for mobility, payload operation, information processing, and communication. Mobility requirements typically place an extraordinary demand on the specific energy (Wh/kg) and specific power (W/kg) of the power source; the actual distribution of the energy between mobility and other system functions could vary substantially with the mission type. The power requirements for continuous mobility can vary from 100-1000 W/kg depending on the terrain, ground speed and flight speed. Even with the power source accounting for 30% of the mass of the vehicle, the best of rechargeable batteries can provide only up to 1-2 hours of run-time for a continuous power demand at 100W/kg. In the case of micro-aerial vehicles with flight speed requirements in the range of 5-15 m s-1, the mission times rarely exceed 20 minutes [2]. Further, the power required during take-off and hover can be twice or thrice that needed for steady level flight, and thus the number and sequence of such events is also limited by the mass and size of the power source. For operations such as "perch and stare" or "silent watch" the power demand is often only a tenth of that required during continuous flight. Thus, variation in power demand during various phases of the mission importantly affects the power source selection.

  11. Response Surface Energy Modeling of an Electric Vehicle over a Reduced Composite Drive Cycle

    SciTech Connect

    Jehlik, Forrest; LaClair, Tim J.

    2014-04-01

    Response surface methodology (RSM) techniques were applied to develop a predictive model of electric vehicle (EV) energy consumption over the Environmental Protection Agency's (EPA) standardized drive cycles. The model is based on measurements from a synthetic composite drive cycle. The synthetic drive cycle is a minimized statistical composite of the standardized urban (UDDS), highway (HWFET), and US06 cycles. The composite synthetic drive cycle is 20 minutes in length thereby reducing testing time of the three standard EPA cycles by over 55%. Vehicle speed and acceleration were used as model inputs for a third order least squared regression model predicting vehicle battery power output as a function of the drive cycle. The approach reduced three cycles and 46 minutes of drive time to a single test of 20 minutes. Application of response surface modeling to the synthetic drive cycle is shown to predict energy consumption of the three EPA cycles within 2.6% of the actual measured values. Additionally, the response model may be used to predict energy consumption of any cycle within the speed/acceleration envelope of the synthetic cycle. This technique results in reducing test time, which additionally provides a model that may be used to expand the analysis and understanding of the vehicle under consideration.

  12. 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

  13. 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.

  14. Vehicle test report: Electric Vehicle Associates electric conversion of an AMC Pacer

    NASA Technical Reports Server (NTRS)

    Price, T. W.; Wirth, V. A., Jr.; Pampa, M. F.

    1981-01-01

    The change of pace, an electric vehicle was tested. These tests were performed to characterize certain parameters of the electric vehicle pacer and to provide baseline data that can be used for the comparison of improved batteries that may be incorporated into the vehicle at a later time. The vehicle tests were concentrated on the electrical drive subsystem, the batteries, controller and motor. Coastdowns to characterize the road load, and range evaluations for both cyclic and constant speed conditions were performed. The vehicle's performance was evaluated by comparing its constant speed range performance with described vehicles. It is found that the pacer performance is approximately equal to the majority of the vehicles tested in the 1977 assessment.

  15. 36 CFR 1192.175 - High-speed rail cars, monorails and systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false High-speed rail cars... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems, including but not limited to those using “maglev” or high...

  16. 36 CFR 1192.175 - High-speed rail cars, monorails and systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true High-speed rail cars... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems, including but not limited to those using “maglev” or high...

  17. 36 CFR 1192.175 - High-speed rail cars, monorails and systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false High-speed rail cars... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems, including but not limited to those using “maglev” or high...

  18. 36 CFR 1192.175 - High-speed rail cars, monorails and systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false High-speed rail cars... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.175 High-speed rail cars, monorails and systems. (a) All cars for high-speed rail systems, including but not limited to those using “maglev” or high...

  19. 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.

  20. 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.

  1. Amphibious Vehicle Propulsion System. Volume 1

    DTIC Science & Technology

    1990-01-30

    7 COSATI CODES 18 SUBJECT TERMS (Continue on reverse if necessary and identify by block number) ;’ELD GROUP SUB-GROUP ELECTRIC DRIVE MILITARY VEHICLE ...RPM. The control- the vehicle prime mover and supplies electrical power to ler is used to start and stop the motor and senses faulti the motor. The...REPORT FOR ELECTRIC WATER PROPULSION SYSTEM FOR A HIGH SPEED TRACKED AMPHIBIOUS VEHICLE TABLE OF CONTENTS SECTION TITLE PAGE 1. Introduction

  2. The Study of the Rapid Acquisition Mine Resistant Ambush Protected (MRAP) Vehicle Program and Its Impact on the Warfighter

    DTIC Science & Technology

    2013-06-01

    20 D. FIELDING SPEED ........................................................................................ 21 E...Chart .....................................19 Figure 8. The MRAP Family of Vehicles (From Johnson, 2013?) ................................. 21 Figure 9...Vehicle (Unit) Costs by LRIP ......................................................53 Figure 21 . RG-31 Per Vehicle (Unit) Costs by LRIP

  3. The actual goals of geoethics

    NASA Astrophysics Data System (ADS)

    Nemec, Vaclav

    2014-05-01

    The most actual goals of geoethics have been formulated as results of the International Conference on Geoethics (October 2013) held at the geoethics birth-place Pribram (Czech Republic): In the sphere of education and public enlightenment an appropriate needed minimum know how of Earth sciences should be intensively promoted together with cultivating ethical way of thinking and acting for the sustainable well-being of the society. The actual activities of the Intergovernmental Panel of Climate Changes are not sustainable with the existing knowledge of the Earth sciences (as presented in the results of the 33rd and 34th International Geological Congresses). This knowledge should be incorporated into any further work of the IPCC. In the sphere of legislation in a large international co-operation following steps are needed: - to re-formulate the term of a "false alarm" and its legal consequences, - to demand very consequently the needed evaluation of existing risks, - to solve problems of rights of individuals and minorities in cases of the optimum use of mineral resources and of the optimum protection of the local population against emergency dangers and disasters; common good (well-being) must be considered as the priority when solving ethical dilemmas. The precaution principle should be applied in any decision making process. Earth scientists presenting their expert opinions are not exempted from civil, administrative or even criminal liabilities. Details must be established by national law and jurisprudence. The well known case of the L'Aquila earthquake (2009) should serve as a serious warning because of the proven misuse of geoethics for protecting top Italian seismologists responsible and sentenced for their inadequate superficial behaviour causing lot of human victims. Another recent scandal with the Himalayan fossil fraud will be also documented. A support is needed for any effort to analyze and to disclose the problems of the deformation of the contemporary

  4. High speed nozzles task

    NASA Technical Reports Server (NTRS)

    Hamed, Awatef

    1995-01-01

    Supersonic cruise exhaust nozzles for advanced applications are optimized for a high nozzle pressure ratio (NPR) at design supersonic cruise Mach number and altitude. The performance of these nozzles with large expansion ratios are severely degraded for operations at subsonic speeds near sea level for NPR significantly less than the design values. The prediction of over-expanded 2DCD nozzles performance is critical to evaluating the internal losses and to the optimization of the integrated vehicle and propulsion system performance. The reported research work was aimed at validating and assessing existing computational methods and turbulence models for predicting the flow characteristics and nozzle performance at over-expanded conditions. Flow simulations in 2DCD nozzles were performed using five different turbulence models. The results are compared with the experimental data for the wall pressure distribution and thrust and flow coefficients at over-expanded static conditions.

  5. Analyzing the influence of median cross-section design on highway safety using vehicle dynamics simulations.

    PubMed

    Stine, Jason S; Hamblin, Bridget C; Brennan, Sean N; Donnell, Eric T

    2010-11-01

    Although vehicle dynamics simulations have long been used in vehicle design and crash reconstruction, their use for highway design is rare. This paper investigates the safety of highway medians through iterative simulations of off-road median encroachments. The commercially available software CarSim was used to simulate over one hundred thousand encroachments, representing the entire passenger vehicle fleet and a wide range of encroachment angles, departure speeds, steering inputs, and braking inputs. Each individual simulation output was then weighted using data from previous studies to reflect the probability of each specific accident scenario occurring in a real-life median encroachment. Results of this analysis illustrate the relative influence of median cross-section geometry on the resulting accident outcomes. The simulations indicate that the overall safety of a highway median depends on the occurrence of both vehicle rollover and median crossover events, and the cross-section shape, slope, and width are all shown to greatly affect each of these incidents. An evaluation of the simulation results was conducted with vehicle trajectories from previous experimental crash tests. Further assessment of the aggregate simulation results to actual crash data was achieved through comparison with several databases of crash statistics. Both efforts showed a strong agreement between the simulations and the real-life crash data.

  6. Study for Air Vehicles at High Speeds, Identifying the Potential Benefits to Transport Aircraft of a Continuously Variable Geometry Trailing-Edge Structure that can be Utilized for Aircraft Control, Trim, Load-Alleviation, and High Lift

    DTIC Science & Technology

    2011-08-01

    1.58 for deltas , Ref.16. The GR is a function of CLmax, wing loading (W/S), rolling friction (µ), Thrust (T) and Lift Induced Drag factor (k). VSTALL...5.2.10 L/D – CL, M 0.75, AR 6 WING + TAILPLANE, Effect of Flap Angle (Plain Flap ) CDi Wing CDi Tail CDo PITCH TRIMMED CASES δTE CL...Geometry and Modelling 6.2. High Speed (M 0.75) Performance, Clean Wing , Plain Flaps and Variable TE 6.3. Low Speed (M 0.20) Performance 6.4. Stability

  7. 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.

  8. Low speed phaselock speed control system. [for brushless dc motor

    NASA Technical Reports Server (NTRS)

    Fulcher, R. W.; Sudey, J. (Inventor)

    1975-01-01

    A motor speed control system for an electronically commutated brushless dc motor is provided which includes a phaselock loop with bidirectional torque control for locking the frequency output of a high density encoder, responsive to actual speed conditions, to a reference frequency signal, corresponding to the desired speed. The system includes a phase comparator, which produces an output in accordance with the difference in phase between the reference and encoder frequency signals, and an integrator-digital-to-analog converter unit, which converts the comparator output into an analog error signal voltage. Compensation circuitry, including a biasing means, is provided to convert the analog error signal voltage to a bidirectional error signal voltage which is utilized by an absolute value amplifier, rotational decoder, power amplifier-commutators, and an arrangement of commutation circuitry.

  9. 40 CFR 205.52 - Vehicle noise emission standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Vehicle noise emission standards. 205... ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Medium and Heavy Trucks § 205.52 Vehicle noise emission standards. (a) Low Speed Noise Emission Standard. Vehicles which are manufactured...

  10. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part I. Black carbon.

    PubMed

    Wang, Yang; Xing, Zhenyu; Xu, Hui; Du, Ke

    2016-12-01

    Compressed natural gas (CNG) is considered to be a "cleaner" fuel compared to other fossil fuels. Therefore, it is used as an alternative fuel in motor vehicles to reduce emissions of air pollutants in transportation. To quantify "how clean" burning CNG is compared to burning gasoline, quantification of pollutant emissions under the same driving conditions for motor vehicles with different fuels is needed. In this study, a fleet of bi-fuel vehicles was selected to measure the emissions of black carbon (BC), carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) for driving in CNG mode and gasoline mode respectively under the same set of constant speeds and accelerations. Comparison of emission factors (EFs) for the vehicles burning CNG and gasoline are discussed. This part of the paper series reports BC EFs for bi-fuel vehicles driving on the real road, which were measured using an in situ method. Our results show that burning CNG will lead to 54%-83% reduction in BC emissions per kilometer, depending on actual driving conditions. These comparisons show that CNG is a cleaner fuel than gasoline for motor vehicles in terms of BC emissions and provide a viable option for reducing BC emissions cause by transportation.

  11. Further validation of artificial neural network-based emissions simulation models for conventional and hybrid electric vehicles.

    PubMed

    Tóth-Nagy, Csaba; Conley, John J; Jarrett, Ronald P; Clark, Nigel N

    2006-07-01

    With the advent of hybrid electric vehicles, computer-based vehicle simulation becomes more useful to the engineer and designer trying to optimize the complex combination of control strategy, power plant, drive train, vehicle, and driving conditions. With the desire to incorporate emissions as a design criterion, researchers at West Virginia University have developed artificial neural network (ANN) models for predicting emissions from heavy-duty vehicles. The ANN models were trained on engine and exhaust emissions data collected from transient dynamometer tests of heavy-duty diesel engines then used to predict emissions based on engine speed and torque data from simulated operation of a tractor truck and hybrid electric bus. Simulated vehicle operation was performed with the ADVISOR software package. Predicted emissions (carbon dioxide [CO2] and oxides of nitrogen [NO(x)]) were then compared with actual emissions data collected from chassis dynamometer tests of similar vehicles. This paper expands on previous research to include different driving cycles for the hybrid electric bus and varying weights of the conventional truck. Results showed that different hybrid control strategies had a significant effect on engine behavior (and, thus, emissions) and may affect emissions during different driving cycles. The ANN models underpredicted emissions of CO2 and NO(x) in the case of a class-8 truck but were more accurate as the truck weight increased.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Actualizing Flexible National Security Space Systems

    DTIC Science & Technology

    2011-01-01

    single launch vehicle is a decision unique to small satellites that adds an extra dimension to the launch risk calculation. While bundling...following a launch failure. The ability to bundle multiple payloads on a single launch vehicle is a decision unique to small satellites that adds an extra ... dimension to the launch risk calculation. While bundling multiple small satellites on a single launch vehicle spreads the initial launch cost across

  17. Speed Management Strategies; A Systematic Review

    PubMed Central

    Sadeghi-Bazargani, Homayoun; Saadati, Mohammad

    2016-01-01

    Objective: To systematically identify the various methods of speed management and their effects. Methods: A systematic search was performed in Science Direct, Ovid Medline, Scopus, PubMed and ProQuest databases from April to June 2015. Hand searching and reference of selected articles were used to improve article identification. Articles published after 1990 which had reported on efficacy/effectiveness of speed management strategies were included. Data were extracted using pre-defined extraction table. Results: Of the 803 retrieved articles, 22 articles were included in this review. Most of the included articles (63%) had before-after design and were done in European countries. Speed cameras, engineering schemes, intelligent speed adaption (ISA), speed limits and zones, vehicle activated sign and integrated strategies were the most common strategies reported in the literature. Various strategies had different effects on mean speed of the vehicles ranging from 1.6 to 10 km/h. Moreover, 8-65% and 11-71% reduction was reported in person injured accidents and fatal accidents, respectively as a result of employing various strategies. Conclusion: Literature revealed positive effects of various speed management strategies. Using various strategies was mostly dependent on road characteristics, driver’s attitude about the strategy as well as economic and technological capabilities of the country. Political support is considered as a main determinant in selecting speed management strategies. PMID:27540546

  18. Electric Vehicle Site Operator Program

    NASA Astrophysics Data System (ADS)

    1992-05-01

    Kansas State University, with funding support from federal, state, public, and private companies, is participating in the Department of Energy's Electric Vehicle Site Operator Program. Through participation is this program, Kansas State is demonstrating, testing, and evaluating electric or hybrid vehicle technology. This participation will provide organizations the opportunity to examine the latest EHV prototypes under actual operating conditions. KSU proposes to purchase one electric or hybrid van and four electric cars during the first two years of this five year program. KSU has purchased one G-Van built by Conceptor Industries, Toronto, Canada and has initiated a procurement order to purchase two Soleq 1992 Ford EVcort stationwagons.

  19. Electric Vehicle Site Operator Program

    SciTech Connect

    Not Available

    1992-01-01

    Kansas State University, with funding support from federal, state, public, and private companies, is participating in the Department of Energy's Electric Vehicle Site Operator Program. Through participation is this program, Kansas State is demonstrating, testing, and evaluating electric or hybrid vehicle technology. This participation will provide organizations the opportunity to examine the latest EHV prototypes under actual operating conditions. KSU proposes to purchase one (1) electric or hybrid van and four (4) electric cars during the first two years of this five year program. KSU has purchased one G-Van built by Conceptor Industries, Toronto, Canada and has initiated a procurement order to purchase two (2) Soleq 1992 Ford EVcort stationwagons.

  20. X-34 Vehicle Aerodynamic Characteristics

    NASA Technical Reports Server (NTRS)

    Brauckmann, Gregory J.

    1998-01-01

    The X-34, being designed and built by the Orbital Sciences Corporation, is an unmanned sub-orbital vehicle designed to be used as a flying test bed to demonstrate key vehicle and operational technologies applicable to future reusable launch vehicles. The X-34 will be air-launched from an L-1011 carrier aircraft at approximately Mach 0.7 and 38,000 feet altitude, where an onboard engine will accelerate the vehicle to speeds above Mach 7 and altitudes to 250,000 feet. An unpowered entry will follow, including an autonomous landing. The X-34 will demonstrate the ability to fly through inclement weather, land horizontally at a designated site, and have a rapid turn-around capability. A series of wind tunnel tests on scaled models was conducted in four facilities at the NASA Langley Research Center to determine the aerodynamic characteristics of the X-34. Analysis of these test results revealed that longitudinal trim could be achieved throughout the design trajectory. The maximum elevon deflection required to trim was only half of that available, leaving a margin for gust alleviation and aerodynamic coefficient uncertainty. Directional control can be achieved aerodynamically except at combined high Mach numbers and high angles of attack, where reaction control jets must be used. The X-34 landing speed, between 184 and 206 knots, is within the capabilities of the gear and tires, and the vehicle has sufficient rudder authority to control the required 30-knot crosswind.

  1. Vortex Flows at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Wilcox, Floyd J., Jr.; Bauer, Steven X. S.; Allen, Jerry M.

    2003-01-01

    A review of research conducted at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) into high-speed vortex flows during the 1970s, 1980s, and 1990s is presented. The data are for flat plates, cavities, bodies, missiles, wings, and aircraft with Mach numbers of 1.5 to 4.6. Data are presented to show the types of vortex structures that occur at supersonic speeds and the impact of these flow structures on vehicle performance and control. The data show the presence of both small- and large-scale vortex structures for a variety of vehicles, from missiles to transports. For cavities, the data show very complex multiple vortex structures exist at all combinations of cavity depth to length ratios and Mach number. The data for missiles show the existence of very strong interference effects between body and/or fin vortices. Data are shown that highlight the effect of leading-edge sweep, leading-edge bluntness, wing thickness, location of maximum thickness, and camber on the aerodynamics of and flow over delta wings. Finally, a discussion of a design approach for wings that use vortex flows for improved aerodynamic performance at supersonic speeds is presented.

  2. Calibration of Speed Enforcement Down-The-Road Radars.

    PubMed

    Jendzurski, John; Paulter, Nicholas G

    2009-01-01

    We examine the measurement uncertainty associated with different methods of calibrating the ubiquitous down-the-road (DTR) radar used in speed enforcement. These calibration methods include the use of audio frequency sources, tuning forks, a fifth wheel attached to the rear of the vehicle with the radar unit, and the speedometer of the vehicle. We also provide an analysis showing the effect of calibration uncertainty on DTR-radar speed measurement uncertainty.

  3. Results of a space shuttle vehicle ferry configuration afterbody fairing optimization study using a 140A/B 0.0405-scale model orbiter (43-0) in the Rockwell International 7.75 by 11.0 ft low speed wind tunnel (OA124)

    NASA Technical Reports Server (NTRS)

    Houlihan, S. R.

    1975-01-01

    Experimental aerodynamic investigations were conducted on a dual-strut mounted 0.0405-scale representation of the 140A/B outer mold line space shuttle orbiter vehicle. The tests, conducted from 11 Oct., 1974 through 22 Oct., 1974, were primarily to investigate aerodynamic stability and control characteristics of the space shuttle orbiter ferry configuration. Four afterbody fairing configurations and various additions to them in the form of horizontal and ventral fins strakes and other aerodynamic protuberances were tested. Base line data on the basic orbiter with MPS nozzles and bodyflap were recorded. The drag of the optimum ferry configuration was increased to the level of the basic orbiter for possible flight test configurations by the addition of two sizes of perforated speed brakes on the tail cone surface.

  4. Gearbox assembly for vehicles

    SciTech Connect

    Imaizumi, M.; Masumura, M.; Ishikawa, T.; Hosoya, E.

    1987-01-13

    A gearbox assembly is described for a vehicle for transmitting an output of an engine to driving wheels of the vehicle, comprising: a main gearbox receiving the output and having plural forward gear-shift steps; a shift lever; a sub gearbox coupled to an output of the main gearbox having at least two relatively high and low speed gearshift steps (GH,GL) and a reverse transmission system (GR), the two steps and the reverse transmission system being selectively established through switching operation of the shift lever; wherein the sub gearbox further comprises: a rotary member connected to the shift lever for selecting one of the steps and the reverse transmission system according to its rotation; a stopper mechanism engaging the rotary member for preventing the rotary member from rotating to a position where the reverse transmission system is established; and interlinking means between the stopper mechanism and the main gearbox for releasing the stopper mechanism only when the main gearbox is in neutral or in a low speed gear-shift step; wherein the stopper mechanism comprises: a cam rotatable in response to the gear-shift operation of the main gearbox; a stopper lever one end of which faces the periphery of the cam and the other end facing the rotary member, the stopper lever being pivotally supported at its middle portion; and a spring urging the stopper level to abut against the periphery of the cam.

  5. 32 CFR 636.22 - Speed regulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... (iii) The flashing, yellow, caution lights are in operation. (3) Fort Stewart housing areas, 20 miles... vehicles and will obey the following off-road driving speeds: Day Driving: Trails, 16 MPH Cross County, 6 MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving: Trails, 4...

  6. 32 CFR 636.22 - Speed regulations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... (iii) The flashing, yellow, caution lights are in operation. (3) Fort Stewart housing areas, 20 miles... vehicles and will obey the following off-road driving speeds: Day Driving: Trails, 16 MPH Cross County, 6 MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving: Trails, 4...

  7. 32 CFR 636.22 - Speed regulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the area. (iii) The flashing, yellow, caution lights are in operation. (3) Fort Stewart housing areas... tactical vehicles and will obey the following off-road driving speeds: Day Driving: Trails, 16 MPH Cross County, 6 MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving:...

  8. 32 CFR 636.22 - Speed regulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the area. (iii) The flashing, yellow, caution lights are in operation. (3) Fort Stewart housing areas... tactical vehicles and will obey the following off-road driving speeds: Day Driving: Trails, 16 MPH Cross County, 6 MPH Night Driving: Trails, 5 MPH (with headlights) Cross Country, 5 MPH Night Driving:...

  9. Hybrid Control of Electric Vehicle Lateral Dynamics Stabilization

    NASA Astrophysics Data System (ADS)

    Tabti, Khatir; Bourahla, Mohamend; Mostefai, Lotfi

    2013-01-01

    This paper presents a novel method for motion control applied to driver stability system of an electric vehicle with independently driven wheels. By formulating the vehicle dynamics using an approximating the tire-force characteristics into piecewise affine functions, the vehicle dynamics cen be described as a linear hybrid dynamical system to design a hybrid model predictive controller. This controller is expected to make the yaw rate follow the reference ensuring the safety of the car passengers. The vehicle speed is estimated using a multi-sensor data fusion method. Simulation results in Matlab/Simulink have shown that the proposed control scheme takes advantages of electric vehicle and enhances the vehicle stability.

  10. Heel and toe driving on fuel cell vehicle

    DOEpatents

    Choi, Tayoung; Chen, Dongmei

    2012-12-11

    A system and method for providing nearly instantaneous power in a fuel cell vehicle. The method includes monitoring the brake pedal angle and the accelerator pedal angle of the vehicle, and if the vehicle driver is pressing both the brake pedal and the accelerator pedal at the same time and the vehicle is in a drive gear, activating a heel and toe mode. When the heel and toe mode is activated, the speed of a cathode compressor is increased to a predetermined speed set-point, which is higher than the normal compressor speed for the pedal position. Thus, when the vehicle brake is removed, the compressor speed is high enough to provide enough air to the cathode, so that the stack can generate nearly immediate power.

  11. Time optimal paths for high speed maneuvering

    SciTech Connect

    Reister, D.B.; Lenhart, S.M.

    1993-01-01

    Recent theoretical results have completely solved the problem of determining the minimum length path for a vehicle with a minimum turning radius moving from an initial configuration to a final configuration. Time optimal paths for a constant speed vehicle are a subset of the minimum length paths. This paper uses the Pontryagin maximum principle to find time optimal paths for a constant speed vehicle. The time optimal paths consist of sequences of axes of circles and straight lines. The maximum principle introduces concepts (dual variables, bang-bang solutions, singular solutions, and transversality conditions) that provide important insight into the nature of the time optimal paths. We explore the properties of the optimal paths and present some experimental results for a mobile robot following an optimal path.

  12. Downhill simplex approach for vehicle headlights detection

    NASA Astrophysics Data System (ADS)

    Kang, Ho-Joong; Kim, Ho-Kun; Oh, Il-Whan; Choi, Kyoung-Ho

    2014-03-01

    Nighttime vehicle detection is an essential problem to be solved in the development of highway surveillance systems that provide information about the vehicle speed, traffic volume, and traffic jams, and so on. In this paper, a novel downhill simplex approach for vehicle headlights detection is presented. In the proposed approach, a rough position of vehicle headlights is detected first. Then, a downhill simplex optimization approach is adopted to find the accurate location of vehicle headlights. For the optimization process, a novel cost function is designed and various headlights are evaluated for possible headlight positions on the detected vehicles, locating an optimal headlight position. Simulation results are provided to show the robustness of the proposed approach for headlights detection.

  13. Experimental Evaluation of the Effect of Angle-of-attack on the External Aerodynamics and Mass Capture of a Symmetric Three-engine Air-breathing Launch Vehicle Configuration at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Kim, Hyun D.; Frate, Franco C.

    2001-01-01

    A subscale aerodynamic model of the GTX air-breathing launch vehicle was tested at NASA Glenn Research Center's 10- by 10-Foot Supersonic Wind Tunnel from Mach 2.0 to 3.5 at various angles-of-attack. The objective of the test was to investigate the effect of angle-of-attack on inlet mass capture, inlet diverter effectiveness, and the flowfield at the cowl lip plane. The flow-through inlets were tested with and without boundary-layer diverters. Quantitative measurements such as inlet mass flow rates and pitot-pressure distributions in the cowl lip plane are presented. At a 3deg angle-of-attack, the flow rates for the top and side inlets were within 8 percent of the zero angle-of-attack value, and little distortion was evident at the cowl lip plane. Surface oil flow patterns showing the shock/boundary-layer interaction caused by the inlet spikes are shown. In addition to inlet data, vehicle forebody static pressure distributions, boundary-layer profiles, and temperature-sensitive paint images to evaluate the boundary-layer transition are presented. Three-dimensional parabolized Navier-Stokes computational fluid dynamics calculations of the forebody flowfield are presented and show good agreement with the experimental static pressure distributions and boundary-layer profiles. With the boundary-layer diverters installed, no adverse aerodynamic phenomena were found that would prevent the inlets from operating at the required angles-of-attack. We recommend that phase 2 of the test program be initiated, where inlet contraction ratio and diverter geometry variations will be tested.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Sensor study for high speed autonomous operations

    NASA Astrophysics Data System (ADS)

    Schneider, Anne; La Celle, Zachary; Lacaze, Alberto; Murphy, Karl; Del Giorno, Mark; Close, Ryan

    2015-06-01

    As robotic ground systems advance in capabilities and begin to fulfill new roles in both civilian and military life, the limitation of slow operational speed has become a hindrance to the wide-spread adoption of these systems. For example, military convoys are reluctant to employ autonomous vehicles when these systems slow their movement from 60 miles per hour down to 40. However, these autonomous systems must operate at these lower speeds due to the limitations of the sensors they employ. Robotic Research, with its extensive experience in ground autonomy and associated problems therein, in conjunction with CERDEC/Night Vision and Electronic Sensors Directorate (NVESD), has performed a study to specify system and detection requirements; determined how current autonomy sensors perform in various scenarios; and analyzed how sensors should be employed to increase operational speeds of ground vehicles. The sensors evaluated in this study include the state of the art in LADAR/LIDAR, Radar, Electro-Optical, and Infrared sensors, and have been analyzed at high speeds to study their effectiveness in detecting and accounting for obstacles and other perception challenges. By creating a common set of testing benchmarks, and by testing in a wide range of real-world conditions, Robotic Research has evaluated where sensors can be successfully employed today; where sensors fall short; and which technologies should be examined and developed further. This study is the first step to achieve the overarching goal of doubling ground vehicle speeds on any given terrain.

  19. Bendix Lunar Roving Vehicle (LRV) Test Article

    NASA Technical Reports Server (NTRS)

    1966-01-01

    An engineer demonstrates a Mobility Test Article (MTA) at NASA's Marshall Space Flight Center (MSFC). This unit, weighing 1/6th as much as an actual vehicle, was built by the Bendix Corporation and was one of the concepts of a possible Lunar Roving Vehicle (LRV). The data provided by the MTA helped in designing the LRV, developed under the direction of MSFC. The LRV was designed to allow Apollo astronauts a greater range of mobility during lunar exploration missions.

  20. The Effect of a Low-Speed Automatic Brake System Estimated From Real Life Data

    PubMed Central

    Isaksson-Hellman, Irene; Lindman, Magdalena

    2012-01-01

    A substantial part of all traffic accidents involving passenger cars are rear-end collisions and most of them occur at low speed. Auto Brake is a feature that has been launched in several passenger car models during the last few years. City Safety is a technology designed to help the driver mitigate, and in certain situations avoid, rear-end collisions at low speed by automatically braking the vehicle. Studies have been presented that predict promising benefits from these kinds of systems, but few attempts have been made to show the actual effect of Auto Brake. In this study, the effect of City Safety, a standard feature on the Volvo XC60 model, is calculated based on insurance claims data from cars in real traffic crashes in Sweden. The estimated claim frequency of rear-end frontal collisions measured in claims per 1,000 insured vehicle years was 23% lower for the City Safety equipped XC60 model than for other Volvo models without the system. PMID:23169133

  1. The effect of a low-speed automatic brake system estimated from real life data.

    PubMed

    Isaksson-Hellman, Irene; Lindman, Magdalena

    2012-01-01

    A substantial part of all traffic accidents involving passenger cars are rear-end collisions and most of them occur at low speed. Auto Brake is a feature that has been launched in several passenger car models during the last few years. City Safety is a technology designed to help the driver mitigate, and in certain situations avoid, rear-end collisions at low speed by automatically braking the vehicle.Studies have been presented that predict promising benefits from these kinds of systems, but few attempts have been made to show the actual effect of Auto Brake. In this study, the effect of City Safety, a standard feature on the Volvo XC60 model, is calculated based on insurance claims data from cars in real traffic crashes in Sweden. The estimated claim frequency of rear-end frontal collisions measured in claims per 1,000 insured vehicle years was 23% lower for the City Safety equipped XC60 model than for other Volvo models without the system.

  2. An Ultrasonic Sensor System Based on a Two-Dimensional State Method for Highway Vehicle Violation Detection Applications

    PubMed Central

    Liu, Jun; Han, Jiuqiang; Lv, Hongqiang; Li, Bing

    2015-01-01

    With the continuing growth of highway construction and vehicle use expansion all over the world, highway vehicle traffic rule violation (TRV) detection has become more and more important so as to avoid traffic accidents and injuries in intelligent transportation systems (ITS) and vehicular ad hoc networks (VANETs). Since very few works have contributed to solve the TRV detection problem by moving vehicle measurements and surveillance devices, this paper develops a novel parallel ultrasonic sensor system that can be used to identify the TRV behavior of a host vehicle in real-time. Then a two-dimensional state method is proposed, utilizing the spacial state and time sequential states from the data of two parallel ultrasonic sensors to detect and count the highway vehicle violations. Finally, the theoretical TRV identification probability is analyzed, and actual experiments are conducted on different highway segments with various driving speeds, which indicates that the identification accuracy of the proposed method can reach about 90.97%. PMID:25894940

  3. Green Vehicle Guide

    MedlinePlus

    ... United States Environmental Protection Agency Search Search Green Vehicle Guide Share Facebook Twitter Google+ Pinterest Contact Us ... your needs. Search for a SmartWay Vehicle Green Vehicle Guide ​What is a green vehicle? Alternative fuels ...

  4. Baseline test data for the EVA electric vehicle. [low energy consumption automobiles

    NASA Technical Reports Server (NTRS)

    Harhay, W. C.; Bozek, J.

    1976-01-01

    Two electric vehicles from Electric Vehicle Associates were evaluated for ERDA at the Transportation Research Center of Ohio. The vehicles, loaded to a gross vehicle weight of 3750 pounds, had a range of 56.3 miles at a steady speed of 25 mph and a 27.4 miles range during acceleration-deceleration tests to a top speed of 30 mph. Energy consumption varied from 0.48 kw-hr/mi. to 0.59 kw-hr/mi.

  5. Analysis of dynamic interaction between catenary and pantograph with experimental verification and performance evaluation in new high-speed line

    NASA Astrophysics Data System (ADS)

    Lee, Jin Hee; Park, Tae Won; Oh, Hyuck Keun; Kim, Young Guk

    2015-08-01

    Understanding the dynamic interaction between the catenary and pantograph of a high-speed train is the one of the most important technical issues in the railway industry. This is because the catenary-pantograph system plays a crucial role in providing electric power to the railway vehicle for stable operation. The aim of the present paper is to estimate the current-collection performance of this system by using numerical analysis, in particular, the flexible multibody dynamic analysis technique. To implement large deformable catenary wires, an absolute nodal coordinate formulation is used for the cable element. Additionally, an efficient contact element and an interactive model for the catenary-pantograph system are introduced. Each developed model is then used for analytical and experimental verification. Actual on-line test results of existing high-speed railway vehicles are presented and used to verify the analysis model. Finally, the performance characteristics of a new 400 km/h-class high-speed line are estimated and evaluated on the basis of international standards.

  6. System and method of vehicle operating condition management

    DOEpatents

    Sujan, Vivek A.; Vajapeyazula, Phani; Follen, Kenneth; Wu, An; Moffett, Barty L.

    2015-10-20

    A vehicle operating condition profile can be determined over a given route while also considering imposed constraints such as deviation from time targets, deviation from maximum governed speed limits, etc. Given current vehicle speed, engine state and transmission state, the present disclosure optimally manages the engine map and transmission to provide a recommended vehicle operating condition that optimizes fuel consumption in transitioning from one vehicle state to a target state. Exemplary embodiments provide for offline and online optimizations relative to fuel consumption. The benefit is increased freight efficiency in transporting cargo from source to destination by minimizing fuel consumption and maintaining drivability.

  7. Ground Vehicle Power and Mobility

    DTIC Science & Technology

    2010-11-17

    foreign oil – Alternative sources sought – wind, solar , bio-mass, waste to energy • Operational issues – Battery usage & limitations – energy & power...Inefficient management/ distribution of power – Demand for soldier- wearable power • Increased emphasis on system power metrics (KPPs, low consumption...Full Vehicle Environmental Test Cell – Ambient temperature control to 160°F – Solar load simulation – Wind speeds up to 20mph in eight possible

  8. Vehicle bridge interaction dynamics and potential applications

    NASA Astrophysics Data System (ADS)

    Yang, Y. B.; Lin, C. W.

    2005-06-01

    The dynamic interaction between a moving vehicle and the sustaining bridge is studied. By the method of modal superposition, closed-form solutions are obtained for the vertical responses of both the bridge and moving vehicle, assuming the vehicle/bridge mass ratio to be small. For both the bridge and vehicle responses, it is confirmed that rather accurate solutions can be obtained by considering only the first mode. The displacement, velocity, and acceleration of the bridge are governed at different extents by two sets of frequencies, i.e., the driving frequency of the vehicle and natural frequencies of the bridge. From the spectrum for the bridge displacement, the vehicle speeds can be shown to be associated with some low-frequency pikes. On the other hand, the vehicle responses are governed by five distinct frequencies that appear as driving frequencies, vehicle frequency, and bridge frequencies with shift. From the vehicle's acceleration spectrum, the first bridge frequency (with shift) is shown to have rather high visibility and can be easily identified. The effects of damping of the vehicle and bridge are evaluated in the numerical studies. Potential applications of the present results, as well as further researches required, are also indicated in the paper.

  9. Monocular precrash vehicle detection: features and classifiers.

    PubMed

    Sun, Zehang; Bebis, George; Miller, Ronald

    2006-07-01

    Robust and reliable vehicle detection from images acquired by a moving vehicle (i.e., on-road vehicle detection) is an important problem with applications to driver assistance systems and autonomous, self-guided vehicles. The focus of this work is on the issues of feature extraction and classification for rear-view vehicle detection. Specifically, by treating the problem of vehicle detection as a two-class classification problem, we have investigated several different feature extraction methods such as principal component analysis, wavelets, and Gabor filters. To evaluate the extracted features, we have experimented with two popular classifiers, neural networks and support vector machines (SVMs). Based on our evaluation results, we have developed an on-board real-time monocular vehicle detection system that is capable of acquiring grey-scale images, using Ford's proprietary low-light camera, achieving an average detection rate of 10 Hz. Our vehicle detection algorithm consists of two main steps: a multiscale driven hypothesis generation step and an appearance-based hypothesis verification step. During the hypothesis generation step, image locations where vehicles might be present are extracted. This step uses multiscale techniques not only to speed up detection, but also to improve system robustness. The appearance-based hypothesis verification step verifies the hypotheses using Gabor features and SVMs. The system has been tested in Ford's concept vehicle under different traffic conditions (e.g., structured highway, complex urban streets, and varying weather conditions), illustrating good performance.

  10. Increasing the Mobility of Dismounted Marines. Small Unit Mobility Enhancement Technologies: Unmanned Ground Vehicles Market Survey

    DTIC Science & Technology

    2009-10-01

    Robotic Porter (Israel Aerospace Industries, Ltd.) ...........................................16 10 . Ranlo (Defense Technologies, Inc... 10 5. Selected Data for Top 15 Candidate Systems...26 10 . Vehicle Mobility (Speed) Scoring

  11. Vehicle Controller

    NASA Technical Reports Server (NTRS)

    1985-01-01

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

  12. Hermes vehicle

    NASA Astrophysics Data System (ADS)

    Cretenet, J.-C.

    1984-10-01

    Projected mission profiles and computational models of the Hermes winged manned reentry vehicle are discussed. Launched into a low orbit with a crew of at most four by the Ariane 5 vehicle, Hermes will serve transportation, crew relief, safety, and freight carriage functions. It will have a nominal 300-500 km circular or 600-900 km heliosynchronous orbit, weigh from 13,500-16,700 kg, and return in hypersonic glide to a wheeled landing. The vehicle dimensions will be 15-18 m length, 6 m height at the tail fin, and a 10 m span. The L/D ratio will be 1.5-1.6, thereby furnishing a cross range of 2500 km. Hermes will have a Shuttle-type fuselage, carbon-carbon nose, and insulation on the extrados designed to keep the structure at 175 C or lower. The avionics will have 3-4 levels of redundance, each mission phase-dependent. Power will be supplied by three fuel cells and a bank of four Ag-Zn batteries. Hardware development is scheduled to begin in 1988.

  13. Bendix Lunar Roving Vehicle (LRV) Test Article

    NASA Technical Reports Server (NTRS)

    1966-01-01

    An engineer demonstrates a Mobility Test Article (MTA) at NASA's Marshall Space Flight Center (MSFC) as he goes down a slope onto soft earth. This unit, weighing 1/6th as much as an actual vehicle, was built by the Bendix Corporation and was one of the concepts of a possible Lunar Roving Vehicle (LRV). The data provided by the MTA helped in designing the Lunar Roving Vehicle (LRV), developed under the direction of MSFC. The LRV was designed to allow Apollo astronauts a greater range of mobility during lunar exploration missions.

  14. Bendix Lunar Roving Vehicle (LRV) Test Article

    NASA Technical Reports Server (NTRS)

    1966-01-01

    An engineer demonstrates a Mobility Test Article (MTA) at NASA's Marshall Space Flight Center (MSFC). This unit, weighing 1/6th as much as an actual vehicle, was built by the Bendix Corporation and was one of the concepts of a possible Lunar Roving Vehicle (LRV). The data provided by the MTA helped in designing the Lunar Roving Vehicle (LRV), developed under the direction of MSFC. The LRV was designed to allow Apollo astronauts a greater range of mobility during lunar exploration missions.

  15. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... series. Conduct 10 stopping tests from a speed of 100 kph or the maximum vehicle speed, whichever is less... apply any electromotive force to the propulsion motor(s). Any electromotive force that is applied to...

  16. 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.

  17. A Collaborative Analysis Tool for Integrated Hypersonic Aerodynamics, Thermal Protection Systems, and RBCC Engine Performance for Single Stage to Orbit Vehicles

    NASA Technical Reports Server (NTRS)

    Stanley, Thomas Troy; Alexander, Reginald; Landrum, Brian

    2000-01-01

    Presented is a computer-based tool that connects several disciplines that are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to every other system, as is the case of SSTO vehicles with air breathing propulsion, which is currently being studied by NASA. An RBCC propulsion system integrates airbreathing and rocket propulsion into a single engine assembly enclosed within a cowl or duct. A typical RBCC propulsion system operates as a ducted rocket up to approximately Mach 3. Then there is a transition to a ramjet mode for supersonic-to-hypersonic acceleration. Around Mach 8 the engine transitions to a scramjet mode. During the ramjet and scramjet modes, the integral rockets operate as fuel injectors. Around Mach 10-12 (the actual value depends on vehicle and mission requirements), the inlet is physically closed and the engine transitions to an integral rocket mode for orbit insertion. A common feature of RBCC propelled vehicles is the high degree of integration between the propulsion system and airframe. At high speeds the vehicle forebody is fundamentally part of the engine inlet, providing a compression surface for air flowing into the engine. The compressed air is mixed with fuel and burned. The combusted mixture must be expanded to an area larger than the incoming stream to provide thrust. Since a conventional nozzle would be too large, the entire lower after body of the vehicle is used as an expansion surface. Because of the high external temperatures seen during atmospheric flight, the design of an airbreathing SSTO vehicle requires delicate tradeoffs between engine design, vehicle shape, and thermal protection system (TPS) sizing in order to produce an optimum system in terms of weight (and cost) and maximum performance. To adequately determine the performance of the engine/vehicle, the Hypersonic Flight Inlet Model (HYFIM) module was designed to interface with the RBCC

  18. Effect of speed and load on ultra-high-speed ball bearings

    NASA Technical Reports Server (NTRS)

    Bamberger, E. N.; Zaretsky, E. V.; Signer, H.

    1975-01-01

    A study was undertaken to determine the effects of speed and load on the operation of 120-mm bore angular-contact ball bearings at speeds to 25,000 rpm and thrust loads to 22,240 newtons (5000 lb). Bearing temperature and power consumption increased with increases in load and/or speed. The effect of load on temperature and power consumption was small relative to the speed effect. Actual measurements of bearing operating contact angle were in excellent agreement with theoretical predictions. Skidding occurred in the bearing in various amounts, generally increasing with speed at given load. The highest amount of skidding, 6 percent, occurred at the highest speed, 25,000 rpm. No visible damage to the bearing surfaces occurred due to the skidding.

  19. Safety of high-speed magnetic-levitation transportation systems. Magnetic-field testing of the TR07 maglev vehicle and system. Volume 2. Appendices. Final report Jun 91-Mar 92

    SciTech Connect

    Dietrich, F.; Robertson, D.; Steiner, G.

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) emissions, both steady (dc) and produced by alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposures to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Volume II-Appendices catalogs and documents detailed magnetic field data files and their specifics (static fields, spectral waveforms, temporal and spatial information) by location.

  20. Safety of high-speed magnetic-levitation transportation systems. Magnetic-field testing of the TR07 maglev vehicle and system. Volume 1. Analysis. Final report Jun 91-Mar 92

    SciTech Connect

    Dietrich, F.; Feero, W.E.

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) emissions, both steady (dc) and produced by alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposures to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Volume I-Analysis summarizes the experimental findings and compares results to common home, work, and power lines emissions for selected spectral bands.

  1. An extended car-following model with consideration of speed guidance at intersections

    NASA Astrophysics Data System (ADS)

    Zhao, Jing; Li, Peng

    2016-11-01

    The main motivation of this paper is to analyze the influences of speed guidance strategies on the driving behaviors under four different traffic signalized conditions and to investigate an extended car-following model to explore how the speed guidance affects two different vehicle types that are intelligent vehicles and traditional vehicles during the phase-change periods. The numerical results show that the proposed model can qualitatively describe the impacts of the speed guidance strategies on vehicle's movement trail including the acceleration strategy, smooth braking strategy, and deceleration strategy. Moreover, the benefits of the speed guidance could be enhanced by lengthening the guiding space range, expanding permitted guiding speed range, and increasing the percentage of the intelligent vehicles.

  2. X-38 Vehicle #132 Landing on First Free Flight

    NASA Technical Reports Server (NTRS)

    1999-01-01

    lifting body designed at 80 percent of the size of a projected emergency crew return vehicle for the International Space Station, although two later versions were planned at 100 percent of the CRV size. The X-38 and the actual CRV are patterned after a lifting-body shape first employed in the Air Force-NASA X-24 lifting-body project in the early to mid-1970s. The current vehicle design is base lined with life support supplies for about nine hours of orbital free flight from the space station. It's landing will be fully automated with backup systems which allow the crew to control orientation in orbit, select a deorbit site, and steer the parafoil, if necessary. The X-38 vehicles (designated V131, V132, and V-131R) are 28.5 feet long, 14.5 feet wide, and weigh approximately 16,000 pounds on average. The vehicles have a nitrogen-gas-operated attitude control system and a bank of batteries for internal power. The actual CRV to be flown in space was expected to be 30 feet long. The X-38 project is a joint effort between the Johnson Space Center, Houston, Texas (JSC), Langley Research Center, Hampton, Virginia (LaRC) and Dryden Flight Research Center, Edwards, California (DFRC) with the program office located at JSC. A contract was awarded to Scaled Composites, Inc., Mojave, California, for construction of the X-38 test airframes. The first vehicle was delivered to the JSC in September 1996. The vehicle was fitted with avionics, computer systems and other hardware at Johnson. A second vehicle was delivered to JSC in December 1996. Flight research with the X-38 at Dryden began with an unpiloted captive-carry flight in which the vehicle remained attached to its future launch vehicle, Dryden's B-52 008. There were four captive flights in 1997 and three in 1998, plus the first drop test on March 12, 1998, using the parachutes and parafoil. Further captive and drop tests occurred in 1999. In March 2000 Vehicle 132 completed its third and final free flight in the highest, fastest

  3. Magnetic Launch Assist Vehicle-Artist's Concept

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This artist's concept depicts a Magnetic Launch Assist vehicle clearing the track and shifting to rocket engines for launch into orbit. The system, formerly referred as the Magnetic Levitation (MagLev) system, is a launch system developed and tested by Engineers at the Marshall Space Flight Center (MSFC) that could levitate and accelerate a launch vehicle along a track at high speeds before it leaves the ground. Using an off-board electric energy source and magnetic fields, a Magnetic Launch Assist system would drive a spacecraft along a horizontal track until it reaches desired speeds. The system is similar to high-speed trains and roller coasters that use high-strength magnets to lift and propel a vehicle a couple of inches above a guideway. A full-scale, operational track would be about 1.5-miles long, capable of accelerating a vehicle to 600 mph in 9.5 seconds, and the vehicle would then shift to rocket engines for launch into orbit. The major advantages of launch assist for NASA launch vehicles is that it reduces the weight of the take-off, the landing gear, the wing size, and less propellant resulting in significant cost savings. The US Navy and the British MOD (Ministry of Defense) are planning to use magnetic launch assist for their next generation aircraft carriers as the aircraft launch system. The US Army is considering using this technology for launching target drones for anti-aircraft training.

  4. High-speed civil transport study. Summary

    NASA Technical Reports Server (NTRS)

    1989-01-01

    A system of study of the potential for a high speed commercial transport aircraft addressed technology, economic, and environmental constraints. Market projections indicated a need for fleets of transport with supersonic or greater cruise speeds by the years 2000 to 2005. The associated design requirements called for a vehicle to carry 250 to 300 passengers over a range of 5000 to 6000 nautical miles. The study was initially unconstrained in terms of vehicle characteristics, such as cruise speed, propulsion systems, fuels, or structural materials. Analyses led to a focus on the most promising vehicle concepts. These were concepts that used a kerosene type fuel and cruised at Mach numbers between 2.0 to 3.2. Further systems study identified the impact of environmental constraints (for community noise, sonic boom, and engine emissions) on economic attractiveness and technological needs. Results showed that current technology cannot produce a viable high speed civil transport. Significant advances are needed to take off gross weight and allow for both economic attractiveness and environment acceptability. Specific technological requirements were identified to meet these needs.

  5. High-speed civil transport study

    NASA Technical Reports Server (NTRS)

    1989-01-01

    A system study of the potential for a high-speed commercial transport has addressed technological, economic, and environmental constraints. Market projections indicate a need for fleets of transports with supersonic or greater cruise speeds by the year 2000 to 2005. The associated design requirements called for a vehicle to carry 250 to 300 passengers over a range of 5,000 to 6,000 nautical miles. The study was initially unconstrained in terms of vehicle characteristic, such as cruise speed, propulsion systems, fuels, or structural materials. Analyses led to a focus on the most promising vehicle concepts. These were concepts that used a kerosene-type fuel and cruised at Mach numbers between 2.0 to 3.2. Further systems study identified the impact of environmental constraints (for community noise, sonic boom, and engine emissions) on economic attractiveness and technological needs. Results showed that current technology cannot produce a viable high-speed civil transport; significant advances are required to reduce takeoff gross weight and allow for both economic attractiveness and environmental accepatability. Specific technological requirements were identified to meet these needs.

  6. Comparison between Computer-Controlled Troposcatter Simulation and an Actual Link.

    DTIC Science & Technology

    The purpose of this report is to compare a computer-controlled troposcatter simulation with data obtained over an actual troposcatter test link. Parameters compared are fade rate, signal amplitude, and fade duration and correlation coefficient distributions, as well as error rates obtained with various high speed digital modems. (Author)

  7. Platform for Testing Robotic Vehicles on Simulated Terrain

    NASA Technical Reports Server (NTRS)

    Lindemann, Randel

    2006-01-01

    The variable terrain tilt platform (VTTP) is a means of providing simulated terrain for mobility testing of engineering models of the Mars Exploration Rovers. The VTTP could also be used for testing the ability of other robotic land vehicles (and small vehicles in general) to move across terrain under diverse conditions of slope and surface texture, and in the presence of obstacles of various sizes and shapes. The VTTP consists mostly of a 16-ft-(4.88-m)-square tilt table. The tilt can be adjusted to any angle between 0 (horizontal) and 25 . The test surface of the table can be left bare; can be covered with hard, high-friction material; or can be covered with sand, gravel, and/or other ground-simulating material or combination of materials to a thickness of as much as 6 in. (approx. 15 cm). Models of rocks, trenches, and other obstacles can be placed on the simulated terrain. For example, for one of the Mars- Rover tests, a high-friction mat was attached to the platform, then a 6-in.- ( 15 cm) deep layer of dry, loose beach sand was deposited on the mat. The choice of these two driving surface materials was meant to bound the range of variability of terrain that the rover was expected to encounter on the Martian surface. At each of the different angles at which tests were performed, for some of the tests, rocklike concrete obstacles ranging in height from 10 to 25 cm were placed in the path of the rover (see figure). The development of the VTTP was accompanied by development of a methodology of testing to characterize the performance and modes of failure of a vehicle under test. In addition to variations in slope, ground material, and obstacles, testing typically includes driving up-slope, down-slope, cross-slope, and at intermediate angles relative to slope. Testing includes recording of drive-motor currents, wheel speeds, articulation of suspension mechanisms, and the actual path of the vehicle over the simulated terrain. The collected data can be used to

  8. Vehicle barrier

    DOEpatents

    Hirsh, Robert A.

    1991-01-01

    A vehicle security barrier which can be conveniently placed across a gate opening as well as readily removed from the gate opening to allow for easy passage. The security barrier includes a barrier gate in the form of a cable/gate member in combination with laterally attached pipe sections fixed by way of the cable to the gate member and lateral, security fixed vertical pipe posts. The security barrier of the present invention provides for the use of cable restraints across gate openings to provide necessary security while at the same time allowing for quick opening and closing of the gate areas without compromising security.

  9. Just Right Vehicle Network (Data Bus) Protocols

    DTIC Science & Technology

    2011-03-16

    this network to research; however, I shall concentrate on defining a precise method to define and assist in properly selecting the network (data bus...recommended – Simple Mathematical selection method used Vehicle Network Selection Conducted 2003-2005 – CAN Data Bus recommended for lower speed hard...real time control – IEEE 1394b Data Bus recommended for high speed hard real time control – Formal Trade Study Process w/ software assisted method used

  10. Development of a lightweight fuel cell vehicle

    NASA Astrophysics Data System (ADS)

    Hwang, J. J.; Wang, D. Y.; Shih, N. C.

    This paper described the development of a fuel cell system and its integration into the lightweight vehicle known as the Mingdao hydrogen vehicle (MHV). The fuel cell system consists of a 5-kW proton exchange membrane fuel cell (PEMFC), a microcontroller and other supported components like a compressed hydrogen cylinder, blower, solenoid valve, pressure regulator, water pump, heat exchanger and sensors. The fuel cell not only propels the vehicle but also powers the supporting components. The MHV performs satisfactorily over a hundred-kilometer drive thus validating the concept of a fuel cell powered zero-emission vehicle. Measurements further show that the fuel cell system has an efficiency of over 30% at the power consumption for vehicle cruise, which is higher than that of a typical internal combustion engine. Tests to improve performance such as speed enhancement, acceleration and fuel efficiency will be conducted in the future work. Such tests will consist of hybridizing with a battery pack.

  11. VEEP: A Vehicle Economy, Emissions, and Performance simulation program

    NASA Technical Reports Server (NTRS)

    Klose, G. J.

    1978-01-01

    The purpose of the VEEP simulation program was to: (1) predict vehicle fuel economy and relative emissions over any specified driving cycle; (2) calculate various measures of vehicle performance (acceleration, passing manuevers, gradeability, top speed), and (3) give information on the various categories of energy dissipation (rolling friction, aerodynamics, accessories, inertial effects, component inefficiences, etc.). The vehicle is described based on detailed subsystem information and numerical parameters characterizing the components of a wide variety of self-propelled vehicles. Conventionally arranged heat engine powered automobiles were emphasized, but with consideration in the design toward the requirement of other types of vehicles.

  12. Emergency vehicle traffic signal preemption system

    NASA Technical Reports Server (NTRS)

    Bachelder, Aaron D. (Inventor); Foster, Conrad F. (Inventor)

    2011-01-01

    An emergency vehicle traffic light preemption system for preemption of traffic lights at an intersection to allow safe passage of emergency vehicles. The system includes a real-time status monitor of an intersection which is relayed to a control module for transmission to emergency vehicles as well as to a central dispatch office. The system also provides for audio warnings at an intersection to protect pedestrians who may not be in a position to see visual warnings or for various reasons cannot hear the approach of emergency vehicles. A transponder mounted on an emergency vehicle provides autonomous control so the vehicle operator can attend to getting to an emergency and not be concerned with the operation of the system. Activation of a priority-code (i.e. Code-3) situation provides communications with each intersection being approached by an emergency vehicle and indicates whether the intersection is preempted or if there is any conflict with other approaching emergency vehicles. On-board diagnostics handle various information including heading, speed, and acceleration sent to a control module which is transmitted to an intersection and which also simultaneously receives information regarding the status of an intersection. Real-time communications and operations software allow central and remote monitoring, logging, and command of intersections and vehicles.

  13. An Exercise in Vehicle Kinematics and Energetics

    ERIC Educational Resources Information Center

    Fischer, Solomon; Gluck, Paul

    2009-01-01

    We physics teachers are forever in search of real-life applications of the theoretical concepts we teach. In mechanics we often utilize vehicle motion exercises, yet most textbook problems involving these are rather tame and deal with constant acceleration. What often captures the imagination of students is the actual performance of cars they…

  14. Mitigating the effects of variable speed on drive-by infrastructure monitoring

    NASA Astrophysics Data System (ADS)

    Thorsen, Andrew; Lederman, George; Oshima, Yoshinobu; Bielak, Jacobo; Noh, Hae Young

    2015-03-01

    Vehicle-based monitoring has the potential to become an accurate and cost-efficient way to monitor infrastructure assets, but a number of challenges must be addressed for such a technique to be implemented widely. The majority of vehicle-based infrastructure sensing has assumed that the vehicle's speed profile is identical every time it passes over the asset of interest. Ultimately, however this technology will be most practical if damage detection schemes can be applied regardless of the speed of the vehicle. Thus methods must be designed to handle speed variability to make this method more practical. In this paper we investigate the effects of variable speed when monitoring infrastructure from the dynamic response of a passing vehicle, which we measure by placing accelerometers on the vehicle of interest. We have conducted a series of laboratory tests to study this phenomenon, in which a vehicle crosses over a scaled model bridge structure with a varying speed profile. We quantify the ability of several features to detect changes in the infrastructure, independent of the variable speed. We show that aligning signals to normalize for speed variability improves the classification results. This work brings us closer to the ultimate goal of using vehicle-based monitoring to ensure more efficient and more reliable infrastructure in the future.

  15. Femur fractures in relatively low speed frontal crashes: the possible role of muscle forces.

    PubMed

    Tencer, Allan F; Kaufman, Robert; Ryan, Kathy; Grossman, David C; Henley, Brad M; Mann, Fred; Mock, Charles; Rivara, Fred; Wang, Stewart; Augenstein, Jeffery; Hoyt, David; Eastman, Brent

    2002-01-01

    In a sample of relatively low speed frontal collisions (mean collision speed change of 40.7 kph) the only major injury suffered by the partly or fully restrained occupant was a femur fracture. However, femur load measurements from standardized barrier crash tests for similar vehicles at a greater speed change (mean of 56.3 kph) showed that in almost all the cases, the occupant's femur would not have fractured because the loads were below fracture threshold. In order to address this discrepancy, the load in the femurs of the occupants in the crash sample were estimated and compared with the femur fracture threshold. Femur load was estimated by inspecting the scene and measuring deformations in each vehicle, defining occupant points of contact and interior surface intrusion, and calculating crash change in velocity and deceleration. From this data, the measured femoral loads from standardized crash test data in a comparable vehicle were scaled to the actual crash by considering crash deceleration, occupant weight, and restraint use. All the occupants (7 males, average age 26.7 years, 13 females, average age 36 years) sustained at least a transverse midshaft fracture of the femur with comminution, which is characteristic of axial compressive impact, causing bending and impaction of the femur. However, the estimated average maximum axial load was 8187 N (S.D. = 4343N), and the average probability for fracture was only 19% (based on the femur fracture risk criteria). In 13 crashes the fracture probability was less than 10%. Two factors were considered to explain the discrepancy. The occupant's femur was out of position (typically the driver's right front leg on the brake) and did not impact the knee bolster, instead hitting stiffer regions of the dashboard. Also, since most victims were drivers with their foot on the brake to avoid the collision, additional compressive force on the femur probably resulted from muscle contraction due to bracing for impact. Adding the

  16. Electric-vehicle batteries

    NASA Astrophysics Data System (ADS)

    Oman, Henry; Gross, Sid

    1995-02-01

    Electric vehicles that can't reach trolley wires need batteries. In the early 1900's electric cars disappeared when owners found that replacing the car's worn-out lead-acid battery costs more than a new gasoline-powered car. Most of today's electric cars are still propelled by lead-acid batteries. General Motors in their prototype Impact, for example, used starting-lighting-ignition batteries, which deliver lots of power for demonstrations, but have a life of less than 100 deep discharges. Now promising alternative technology has challenged the world-wide lead miners, refiners, and battery makers into forming a consortium that sponsors research into making better lead-acid batteries. Horizon's new bipolar battery delivered 50 watt-hours per kg (Wh/kg), compared with 20 for ordinary transport-vehicle batteries. The alternatives are delivering from 80 Wh/kg (nickel-metal hydride) up to 200 Wh/kg (zinc-bromine). A Fiat Panda traveled 260 km on a single charge of its zinc-bromine battery. A German 3.5-ton postal truck traveled 300 km with a single charge in its 650-kg (146 Wh/kg) zinc-air battery. Its top speed was 110 km per hour.

  17. Realizing actual feedback control of complex network

    NASA Astrophysics Data System (ADS)

    Tu, Chengyi; Cheng, Yuhua

    2014-06-01

    In this paper, we present the concept of feedbackability and how to identify the Minimum Feedbackability Set of an arbitrary complex directed network. Furthermore, we design an estimator and a feedback controller accessing one MFS to realize actual feedback control, i.e. control the system to our desired state according to the estimated system internal state from the output of estimator. Last but not least, we perform numerical simulations of a small linear time-invariant dynamics network and a real simple food network to verify the theoretical results. The framework presented here could make an arbitrary complex directed network realize actual feedback control and deepen our understanding of complex systems.

  18. Simulation of stochastic vibration of maglev track inspection vehicle

    NASA Astrophysics Data System (ADS)

    Liu, Xingchu; Guan, Xiqiang; Zhang, Jianwu

    2007-05-01

    The stochastic vibration of a maglev track inspection vehicle is the main factor that has direct influence on the accuracy of geometrical measurements of the maglev tracks on board whenever the inspection vehicle is operated at a certain speed. Based upon the principle of motions of the specified vehicle, a vibration model of 5 dof for the maglev track inspection vehicle is proposed and a numerical example is made for the analysis of dynamic responses of the vehicle in stochastic excitation of the maglev track. Effects of vibrations of the vehicle on the accuracy of measuring displacement by laser triangle method are examined. Simulation results of lateral, vertical, roll, pitch, and yaw vibrations for the maglev track inspection vehicle equipped with the measuring system of high precision are provided for the design of the similar vehicles.

  19. INTEGRATED SPEED ESTIMATION MODEL FOR MULTILANE EXPREESSWAYS

    NASA Astrophysics Data System (ADS)

    Hong, Sungjoon; Oguchi, Takashi

    In this paper, an integrated speed-estimation model is developed based on empirical analyses for the basic sections of intercity multilane expressway un der the uncongested condition. This model enables a speed estimation for each lane at any site under arb itrary highway-alignment, traffic (traffic flow and truck percentage), and rainfall conditions. By combin ing this model and a lane-use model which estimates traffic distribution on the lanes by each vehicle type, it is also possible to es timate an average speed across all the lanes of one direction from a traffic demand by vehicle type under specific highway-alignment and rainfall conditions. This model is exp ected to be a tool for the evaluation of traffic performance for expressways when the performance me asure is travel speed, which is necessary for Performance-Oriented Highway Planning and Design. Regarding the highway-alignment condition, two new estimators, called effective horizo ntal curvature and effective vertical grade, are proposed in this paper which take into account the influence of upstream and downstream alignment conditions. They are applied to the speed-estimation model, and it shows increased accuracy of the estimation.

  20. Quantifying a cellular automata simulation of electric vehicles

    NASA Astrophysics Data System (ADS)

    Hill, Graeme; Bell, Margaret; Blythe, Phil

    2014-12-01

    Within this work the Nagel-Schreckenberg (NS) cellular automata is used to simulate a basic cyclic road network. Results from SwitchEV, a real world Electric Vehicle trial which has collected more than two years of detailed electric vehicle data, are used to quantify the results of the NS automata, demonstrating similar power consumption behavior to that observed in the experimental results. In particular the efficiency of the electric vehicles reduces as the vehicle density increases, due in part to the reduced efficiency of EVs at low speeds, but also due to the energy consumption inherent in changing speeds. Further work shows the results from introducing spatially restricted speed restriction. In general it can be seen that induced congestion from spatially transient events propagates back through the road network and alters the energy and efficiency profile of the simulated vehicles, both before and after the speed restriction. Vehicles upstream from the restriction show a reduced energy usage and an increased efficiency, and vehicles downstream show an initial large increase in energy usage as they accelerate away from the speed restriction.

  1. Children's Rights and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1982-01-01

    Educators need to seriously reflect upon the concept of children's rights. Though the idea of children's rights has been debated numerous times, the idea remains vague and shapeless; however, Maslow's theory of self-actualization can provide the children's rights idea with a needed theoretical framework. (Author)

  2. Group Counseling for Self-Actualization.

    ERIC Educational Resources Information Center

    Streich, William H.; Keeler, Douglas J.

    Self-concept, creativity, growth orientation, an integrated value system, and receptiveness to new experiences are considered to be crucial variables to the self-actualization process. A regular, year-long group counseling program was conducted with 85 randomly selected gifted secondary students in the Farmington, Connecticut Public Schools. A…

  3. Culture Studies and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1983-01-01

    True citizenship education is impossible unless students develop the habit of intelligently evaluating cultures. Abraham Maslow's theory of self-actualization, a theory of innate human needs and of human motivation, is a nonethnocentric tool which can be used by teachers and students to help them understand other cultures. (SR)

  4. Humanistic Education and Self-Actualization Theory.

    ERIC Educational Resources Information Center

    Farmer, Rod

    1984-01-01

    Stresses the need for theoretical justification for the development of humanistic education programs in today's schools. Explores Abraham Maslow's hierarchy of needs and theory of self-actualization. Argues that Maslow's theory may be the best available for educators concerned with educating the whole child. (JHZ)

  5. Developing Human Resources through Actualizing Human Potential

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    2012-01-01

    The key to human resource development is in actualizing individual and collective thinking, feeling and choosing potentials related to our minds, hearts and wills respectively. These capacities and faculties must be balanced and regulated according to the standards of truth, love and justice for individual, community and institutional development,…

  6. 50 CFR 253.16 - Actual cost.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Actual cost. 253.16 Section 253.16 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE AID TO FISHERIES FISHERIES ASSISTANCE PROGRAMS Fisheries Finance Program §...

  7. Speed control system for a windmill

    SciTech Connect

    Kenney, C.E.

    1981-06-23

    A speed control system for a windmill having blades which can be feathered for altering speed and with the blades under the control of a mechanism which includes a piston assembly and a fluid governor associated therewith. Spring means are used to feather the blades against the force of the piston assembly which is interconnected with the blades, and the speed of blade rotation actually creates the fluid pressure acting on the piston assembly and a governor is associated with the piston assembly for controlling the position of the piston and thus controlling the feathering of the blades, all according to the speed of rotation of the windmill blades. The windmill can be used for generating electric power, and fail-safe mechanisms are employed for protecting in the event of a windmill blade breakage.

  8. Aircraft Speed Instruments

    NASA Technical Reports Server (NTRS)

    Beij, K Hilding

    1933-01-01

    This report presents a concise survey of the measurement of air speed and ground speed on board aircraft. Special attention is paid to the pitot-static air-speed meter which is the standard in the United States for airplanes. Air-speed meters of the rotating vane type are also discussed in considerable detail on account of their value as flight test instruments and as service instruments for airships. Methods of ground-speed measurement are treated briefly, with reference to the more important instruments. A bibliography on air-speed measurement concludes the report.

  9. Whiteheadian Actual Entitities and String Theory

    NASA Astrophysics Data System (ADS)

    Bracken, Joseph A.

    2012-06-01

    In the philosophy of Alfred North Whitehead, the ultimate units of reality are actual entities, momentary self-constituting subjects of experience which are too small to be sensibly perceived. Their combination into "societies" with a "common element of form" produces the organisms and inanimate things of ordinary sense experience. According to the proponents of string theory, tiny vibrating strings are the ultimate constituents of physical reality which in harmonious combination yield perceptible entities at the macroscopic level of physical reality. Given that the number of Whiteheadian actual entities and of individual strings within string theory are beyond reckoning at any given moment, could they be two ways to describe the same non-verifiable foundational reality? For example, if one could establish that the "superject" or objective pattern of self- constitution of an actual entity vibrates at a specific frequency, its affinity with the individual strings of string theory would be striking. Likewise, if one were to claim that the size and complexity of Whiteheadian 'societies" require different space-time parameters for the dynamic interrelationship of constituent actual entities, would that at least partially account for the assumption of 10 or even 26 instead of just 3 dimensions within string theory? The overall conclusion of this article is that, if a suitably revised understanding of Whiteheadian metaphysics were seen as compatible with the philosophical implications of string theory, their combination into a single world view would strengthen the plausibility of both schemes taken separately. Key words: actual entities, subject/superjects, vibrating strings, structured fields of activity, multi-dimensional physical reality.

  10. Use of a thermophotovoltaic generator in a hybrid electric vehicle

    NASA Astrophysics Data System (ADS)

    Morrison, Orion; Seal, Michael; West, Edward; Connelly, William

    1999-03-01

    Viking 29 is the World's first thermophotovoltaic (TPV) powered automobile. The prototype was funded by the Department of Energy and designed and built by students and faculty at the Vehicle Research Institute (VRI) at Western Washington University. Viking 29 is a series hybrid electric vehicle that utilizes TPV generators to charge its battery pack. Acceleration, speed, and handling compare to modern high performance sports cars, while emissions are cleaner than current internal combustion engine vehicles.

  11. 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.

  12. 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.

  13. Launch vehicles

    NASA Astrophysics Data System (ADS)

    Moss, J. B.

    The basic principles which determine launcher design and hence constrain the spacecraft payload are determined. Some key features of the principal launcher alternatives in Europe and the U.S., namely, the unmanned, expendable Ariane and the manned, substantially reusable, Space Shuttle, are outlined. The equations of motion of the rocket are specialized to the vertical plane, parallel and normal to the flight direction, and to the motion of the center of mass and the pitch rotation. A typical Ariane 2 flight profile for transfer into GTO is illustrated. Some representative mission requirements for spacecraft launches are reviewed. Launch vehicle burnout velocities for spacecraft emplacement are given. Geostationary orbit emplacement, orbital mission performance, and configuration interactions are discussed.

  14. LETTERS AND COMMENTS: An elementary first-postulate measurement of the cosmic limit speed

    NASA Astrophysics Data System (ADS)

    Coleman, Brian

    2004-05-01

    In 1898 Henri Poincaré referred to the speed of light as a probable limit speed but rashly asserted it would never as such be experimentally verifiable. Moving space vehicle measurements of the cosmic limit speed, however, without assuming it equals c, were described by Coleman (2003 Eur. J. Phys. 24 301). A more elementary measurement is also possible, involving two mutually stationary vehicles with a third passing between them. A simple formula gives the limit speed in terms of signal speed c and three time intervals.

  15. Vehicle automation: a remedy for driver stress?

    PubMed

    Funke, G; Matthews, G; Warm, J S; Emo, A K

    2007-08-01

    The present study addressed the effects of stress, vehicle automation and subjective state on driver performance and mood in a simulated driving task. A total of 168 college students participated. Participants in the stress-induction condition completed a 'winter' drive, which included periodic loss of control episodes. Participants in the no-stress-induction condition were not exposed to loss of control. An additional, independent manipulation of vehicle speed was also conducted, consisting of two control conditions requiring manual speed regulation and a third in which vehicle speed was automatically regulated by the simulation. Stress and automation both influenced subjective distress, but the two factors did not interact. Driver performance data indicated that vehicle automation impacted performance similarly in the stress and no-stress conditions. Individual differences in subjective stress response and performance were also investigated. Resource theory provides a framework that partially but not completely explains the relationship between vehicle automation and driver stress. Implications for driver workload, safety and training are discussed.

  16. White-Tailed Deer Response to Vehicle Approach: Evidence of Unclear and Present Danger

    PubMed Central

    Blackwell, Bradley F.; Seamans, Thomas W.; DeVault, Travis L.

    2014-01-01

    The fundamental causes of animal-vehicle collisions are unclear, particularly at the level of animal detection of approaching vehicles and decision-making. Deer-vehicle collisions (DVCs) are especially costly in terms of animal mortality, property damage, and safety. Over one year, we exposed free-ranging white-tailed deer (Odocoileus virginianus) to vehicle approach under low ambient light conditions, from varying start distances, and vehicle speeds from 20 km/h to approximately 90 km/h. We modeled flight response by deer to an approaching vehicle and tested four hypotheses: 1) flight-initiation distance (FID) would correlate positively with start distance (indicating a spatial margin of safety); 2) deer would react to vehicle speed using a temporal margin of safety; 3) individuals reacting at greater FIDs would be more likely to cross the path of the vehicle; and 4) crossings would correlate positively with start distance, approach speed, and distance to concealing/refuge cover. We examined deer responses by quantiles. Median FID was 40% of start distance, irrespective of start distance or approach speed. Converting FID to time-to-collision (TTC), median TTC was 4.6 s, but uncorrelated with start distance or approach speed. The likelihood of deer crossing in front of the vehicle was not associated with greater FIDs or other explanatory variables. Because deer flight response to vehicle approach was highly variable, DVCs should be more likely with increasing vehicle speeds because of lower TTCs for a given distance. For road sections characterized by frequent DVCs, we recommend estimating TTC relative to vehicle speed and candidate line-of-sight distances adjusted downward by (1-P), where P represents our findings for the proportion of start distance by which >75% of deer had initiated flight. Where road design or conservation goals limit effectiveness of line-of-sight maintenance, we suggest incorporation of roadway obstacles that force drivers to slow vehicles

  17. White-tailed deer response to vehicle approach: evidence of unclear and present danger.

    PubMed

    Blackwell, Bradley F; Seamans, Thomas W; DeVault, Travis L

    2014-01-01

    The fundamental causes of animal-vehicle collisions are unclear, particularly at the level of animal detection of approaching vehicles and decision-making. Deer-vehicle collisions (DVCs) are especially costly in terms of animal mortality, property damage, and safety. Over one year, we exposed free-ranging white-tailed deer (Odocoileus virginianus) to vehicle approach under low ambient light conditions, from varying start distances, and vehicle speeds from 20 km/h to approximately 90 km/h. We modeled flight response by deer to an approaching vehicle and tested four hypotheses: 1) flight-initiation distance (FID) would correlate positively with start distance (indicating a spatial margin of safety); 2) deer would react to vehicle speed using a temporal margin of safety; 3) individuals reacting at greater FIDs would be more likely to cross the path of the vehicle; and 4) crossings would correlate positively with start distance, approach speed, and distance to concealing/refuge cover. We examined deer responses by quantiles. Median FID was 40% of start distance, irrespective of start distance or approach speed. Converting FID to time-to-collision (TTC), median TTC was 4.6 s, but uncorrelated with start distance or approach speed. The likelihood of deer crossing in front of the vehicle was not associated with greater FIDs or other explanatory variables. Because deer flight response to vehicle approach was highly variable, DVCs should be more likely with increasing vehicle speeds because of lower TTCs for a given distance. For road sections characterized by frequent DVCs, we recommend estimating TTC relative to vehicle speed and candidate line-of-sight distances adjusted downward by (1-P), where P represents our findings for the proportion of start distance by which >75% of deer had initiated flight. Where road design or conservation goals limit effectiveness of line-of-sight maintenance, we suggest incorporation of roadway obstacles that force drivers to slow vehicles

  18. The Diesel as a Vehicle Engine

    NASA Technical Reports Server (NTRS)

    Neumann, Kurt

    1928-01-01

    The thorough investigation of a Dorner four-cylinder, four-stroke-cycle Diesel engine with mechanical injection led me to investigate more thoroughly the operation of the Diesel as a vehicle engine. Aside from the obvious need of reliability of functioning, a high rotative speed, light weight and economy in heat consumption per horsepower are also indispensable requirements.

  19. Flight vehicle thermal testing with infrared lamps

    NASA Technical Reports Server (NTRS)

    Fields, Roger A.

    1992-01-01

    The verification and certification of new structural material concepts for advanced high speed flight vehicles relies greatly on thermal testing with infrared quartz lamps. The basic quartz heater system characteristics and design considerations are presented. Specific applications are illustrated with tests that were conducted for the X-15, the Space Shuttle, and YF-12 flight programs.

  20. 75 FR 60036 - Federal Motor Vehicle Safety Standards; New Pneumatic Tires for Motor Vehicles With a GVWR of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ...This NPRM proposes to upgrade Federal Motor Vehicle Safety Standard (FMVSS) No. 119, which specifies requirements for new truck tires. We propose to amend FMVSS No. 119 to adopt more stringent endurance test requirements and a new high speed test for several heavy load range tires for vehicles with gross vehicle weight rating (GVWR) of more than 4,536 kilograms (10,000 pounds). We are also......

  1. A Collaborative Analysis Tool for Integrating Hypersonic Aerodynamics, Thermal Protection Systems, and RBCC Engine Performance for Single Stage to Orbit Vehicles

    NASA Technical Reports Server (NTRS)

    Stanley, Thomas Troy; Alexander, Reginald

    1999-01-01

    Presented is a computer-based tool that connects several disciplines that are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to every other system, as is the case of SSTO vehicles with air breathing propulsion, which is currently being studied by NASA. The deficiencies in the scramjet powered concept led to a revival of interest in Rocket-Based Combined-Cycle (RBCC) propulsion systems. An RBCC propulsion system integrates airbreathing and rocket propulsion into a single engine assembly enclosed within a cowl or duct. A typical RBCC propulsion system operates as a ducted rocket up to approximately Mach 3. At this point the transitions to a ramjet mode for supersonic-to-hypersonic acceleration. Around Mach 8 the engine transitions to a scram4jet mode. During the ramjet and scramjet modes, the integral rockets operate as fuel injectors. Around Mach 10-12 (the actual value depends on vehicle and mission requirements), the inlet is physically closed and the engine transitions to an integral rocket mode for orbit insertion. A common feature of RBCC propelled vehicles is the high degree of integration between the propulsion system and airframe. At high speeds the vehicle forebody is fundamentally part of the engine inlet, providing a compression surface for air flowing into the engine. The compressed air is mixed with fuel and burned. The combusted mixture must be expanded to an area larger than the incoming stream to provide thrust. Since a conventional nozzle would be too large, the entire lower after body of the vehicle is used as an expansion surface. Because of the high external temperatures seen during atmospheric flight, the design of an airbreathing SSTO vehicle requires delicate tradeoffs between engine design, vehicle shape, and thermal protection system (TPS) sizing in order to produce an optimum system in terms of weight (and cost) and maximum performance.

  2. Aerodynamics of sounding rockets at supersonic speeds

    NASA Astrophysics Data System (ADS)

    Vira, N. R.

    This dissertation presents a practical and low cost method of computing the aerodynamic characteristics of vehicles such as sounding rockets, high speed bombs, projectiles and guided missiles in supersonic flight. The vehicle configuration consists of a slender axisymmetric body with a conical or ogive noise, cylinders, shoulders and boattails, if any, and have sets of two, three or four fins. Geometry of the fin cross section can be single wedge, double wedge, modified single wedge or modified double wedge. First the aerodynamics of the fins and the body are analyzed separately; then fin body and fore and aft fin interferences are accounted for when they are combined to form the total vehicle. Results and formulas documented in this work are the basis of the supersonic portion of the Theoretical Aerodynamic Derivatives (TAD) computer program operating at the NASA Goddard Space Flight Center.

  3. Effect of vehicle characteristics on unpaved road dust emissions

    NASA Astrophysics Data System (ADS)

    Gillies, J. A.; Etyemezian, V.; Kuhns, H.; Nikolic, D.; Gillette, D. A.

    This paper presents PM 10 fugitive dust emission factors for a range of vehicles types and examines the influence of vehicle and wake characteristics on the strength of emissions from an unpaved road. Vertical profile measurements of mass concentration of the passing plumes were carried out using a series of 3 instrumented towers. PM 10 emission fluxes at each tower were calculated from knowledge of the vertical mass concentration profile, the ambient wind speed and direction, and the time the plume took to pass the towers. The emission factors showed a strong linear dependence on speed and vehicle weight. Emission factors (EF=grams of PM 10 emitted per vehicle kilometer traveled) ranged from approximately EF=0.8×(km h -1) for a light (˜1200 kg) passenger car to EF=48×(km h -1) for large military vehicles (˜18 000 kg). In comparison to emission estimates derived using US EPA AP-42 methods the measured emission factors indicate larger than estimated contributions for speeds generally>10-20 km h -1 and for vehicle weights>3000 kg. The size of a wake created by a vehicle was observed to be dependent on the size of the vehicle, increasing roughly linearly with vehicle height. Injection height of the dust plume is least important to long-range transport of PM 10 under unstable conditions and most important under stable atmospheric conditions.

  4. Two laboratory methods for the calibration of GPS speed meters

    NASA Astrophysics Data System (ADS)

    Bai, Yin; Sun, Qiao; Du, Lei; Yu, Mei; Bai, Jie

    2015-01-01

    The set-ups of two calibration systems are presented to investigate calibration methods of GPS speed meters. The GPS speed meter calibrated is a special type of high accuracy speed meter for vehicles which uses Doppler demodulation of GPS signals to calculate the measured speed of a moving target. Three experiments are performed: including simulated calibration, field-test signal replay calibration, and in-field test comparison with an optical speed meter. The experiments are conducted at specific speeds in the range of 40-180 km h-1 with the same GPS speed meter as the device under calibration. The evaluation of measurement results validates both methods for calibrating GPS speed meters. The relative deviations between the measurement results of the GPS-based high accuracy speed meter and those of the optical speed meter are analyzed, and the equivalent uncertainty of the comparison is evaluated. The comparison results justify the utilization of GPS speed meters as reference equipment if no fewer than seven satellites are available. This study contributes to the widespread use of GPS-based high accuracy speed meters as legal reference equipment in traffic speed metrology.

  5. 77 FR 43216 - Denial of Motor Vehicle Defect Petition and Petition for a Hearing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-24

    ... investigations on Model Year (MY) 2002-2004 Ford Escape and 2001-2004 Mazda Tribute vehicles with certain cruise.... The instructions indicate that damage to the speed (or cruise) control cable can result if the... Mazda Tribute owners that their vehicles' speed (or cruise) control cables may have been damaged...

  6. NPSNET: Real-Time 3D Ground-Based Vehicle Dynamics

    DTIC Science & Technology

    1992-03-01

    9 C. NEWTON -EULER EQUATIONS .................................... 9 1 . Linear And Angular Acceleration............................. 9 2...Baraff, 91]. C. NEWTON -EULER EQUATIONS 1. Linear and Angular Acceleration Two parts of Newton -Euler equations are the translational motion of its...in each time step. 2. Vehicle Speed And Direction The vehicle speed is computed by linear acceleration using Newton -Euler equations. Newton -Euler

  7. Future ultra-speed tube-flight

    NASA Technical Reports Server (NTRS)

    Salter, Robert M.

    1994-01-01

    Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

  8. Emergency vehicle traffic signal preemption system

    NASA Technical Reports Server (NTRS)

    Bachelder, Aaron D. (Inventor); Foster, Conrad F. (Inventor)

    2005-01-01

    An emergency vehicle traffic light preemption system for preemption of traffic lights at an intersection to allow safe passage of emergency vehicles. The system includes a real-time status monitor of an intersection which is relayed to a communications controller for transmission to emergency vehicles as well as to a central dispatch office. The system also provides for audio warnings at an intersection to protect pedestrians who may not be in a position to see visual warnings or for various reasons cannot hear the approach of emergency vehicles. A transponder mounted on an emergency vehicle provides autonomous control so the vehicle operator can attend to getting to an emergency and not be concerned with the operation of the system. Activation of a Code 3 situation provides communications with each intersection being approached by an emergency vehicle and indicates whether the intersection is preempted or if there is any conflict with other approaching emergency vehicles. On-board diagnostics handle various information including heading, speed, and acceleration sent to a communications controller which is transmitted to an intersection and which also simultaneously receives information regarding the status of an intersection.

  9. Propellant Mass Fraction Calculation Methodology for Launch Vehicles and Application to Ares Vehicles

    NASA Technical Reports Server (NTRS)

    Holt, James B.; Monk, Timothy S.

    2009-01-01

    Propellant Mass Fraction (pmf) calculation methods vary throughout the aerospace industry. While typically used as a means of comparison between candidate launch vehicle designs, the actual pmf calculation method varies slightly from one entity to another. It is the purpose of this paper to present various methods used to calculate the pmf of launch vehicles. This includes fundamental methods of pmf calculation that consider only the total propellant mass and the dry mass of the vehicle; more involved methods that consider the residuals, reserves and any other unusable propellant remaining in the vehicle; and calculations excluding large mass quantities such as the installed engine mass. Finally, a historical comparison is made between launch vehicles on the basis of the differing calculation methodologies, while the unique mission and design requirements of the Ares V Earth Departure Stage (EDS) are examined in terms of impact to pmf.

  10. Electric vehicle drive train with direct coupling transmission

    SciTech Connect

    Tankersley, Jerome B.; Boothe, Richard W.; Konrad, Charles E.

    1995-01-01

    An electric vehicle drive train includes an electric motor and an associated speed sensor, a transmission operable in a speed reduction mode or a direct coupled mode, and a controller responsive to the speed sensor for operating the transmission in the speed reduction mode when the motor is below a predetermined value, and for operating the motor in the direct coupled mode when the motor speed is above a predetermined value. The controller reduces the speed of the motor, such as by regeneratively braking the motor, when changing from the speed reduction mode to the direct coupled mode. The motor speed may be increased when changing from the direct coupled mode to the speed reduction mode. The transmission is preferably a single stage planetary gearbox.

  11. Electric vehicle drive train with direct coupling transmission

    DOEpatents

    Tankersley, J.B.; Boothe, R.W.; Konrad, C.E.

    1995-04-04

    An electric vehicle drive train includes an electric motor and an associated speed sensor, a transmission operable in a speed reduction mode or a direct coupled mode, and a controller responsive to the speed sensor for operating the transmission in the speed reduction mode when the motor is below a predetermined value, and for operating the motor in the direct coupled mode when the motor speed is above a predetermined value. The controller reduces the speed of the motor, such as by regeneratively braking the motor, when changing from the speed reduction mode to the direct coupled mode. The motor speed may be increased when changing from the direct coupled mode to the speed reduction mode. The transmission is preferably a single stage planetary gearbox. 6 figures.

  12. Electric vehicle drive train components

    SciTech Connect

    Silver, F.

    1994-12-31

    Power Control Systems has developed a family of electric vehicle drive systems that range from 65 horsepower through 300 horse power. These propulsion systems support vehicle applications ranging from light cars and pickups to buses and trucks weighing as much as 40,000 lbs (18,400 kg). These robust systems are designed specifically for automotive applications including safety, electromagnetic emissions, and environment ruggedness. Dolphin Drive Systems are very flexible. Their inverter controllers are programmable and can be provided as stand alone components matched to customer specified motors. A selection of pre-calibrated systems including motor and inverter/controller can be provided. Accessory tools are also available for customer self programming. Dolphin Drive Systems provide precision control of AC induction motors providing excellent torque-speed performance usually eliminating the need for multistage transmissions. In addition, they are very efficient over a wide speed/torque range. This provides for excellent power management over a variety of continuous speed and stop and go applications.

  13. Speed limits of aircraft

    NASA Technical Reports Server (NTRS)

    Everling, E

    1923-01-01

    This paper is restricted to the question of attainable speed limits and attacks the problem from different angles. Theoretical limits due to air resistance are presented along with design factors which may affect speed such as wing loads, wing areas, wing section shifting, landing speeds, drag-lift ratios, and power coefficients.

  14. Vehicle occupant exposure to carbon monoxide.

    PubMed

    Koushki, P A; al-Dhowalia, K H; Niaizi, S A

    1992-12-01

    This paper focuses on the auto commuting micro-environment and presents typical carbon monoxide (CO) concentrations to which auto commuters in central Riyadh, Saudi Arabia were exposed. Two test vehicles traveling over four main arterial roadways were monitored for inside and outside CO levels during eighty peak and off-peak hours extending over an eight-month period. The relative importance of several variables which explained the variability in CO concentrations inside autos was also assessed. It was found that during peak hours auto commuters were exposed to mean CO levels that ranged from 30 to 40 ppm over trips that typically took between 25 to 40 minutes. The mean ratio of inside to outside CO levels was 0.84. Results of variance component analyses indicated that the most important variables affecting CO concentrations inside autos were, in addition to the smoking of vehicle occupants, traffic volume, vehicle speed, period of day and wind velocity. An increase in traffic volume from 1,000 to 5,000 vehicles per hour (vph) increased mean CO level exposure by 71 percent. An increase in vehicle speed from 14 to 55 km/h reduced mean CO exposure by 36 percent. The number of traffic interruptions had a moderate effect on mean concentrations of CO inside vehicles.

  15. Deterministic prediction of surface wind speed variations

    NASA Astrophysics Data System (ADS)

    Drisya, G. V.; Kiplangat, D. C.; Asokan, K.; Satheesh Kumar, K.

    2014-11-01

    Accurate prediction of wind speed is an important aspect of various tasks related to wind energy management such as wind turbine predictive control and wind power scheduling. The most typical characteristic of wind speed data is its persistent temporal variations. Most of the techniques reported in the literature for prediction of wind speed and power are based on statistical methods or probabilistic distribution of wind speed data. In this paper we demonstrate that deterministic forecasting methods can make accurate short-term predictions of wind speed using past data, at locations where the wind dynamics exhibit chaotic behaviour. The predictions are remarkably accurate up to 1 h with a normalised RMSE (root mean square error) of less than 0.02 and reasonably accurate up to 3 h with an error of less than 0.06. Repeated application of these methods at 234 different geographical locations for predicting wind speeds at 30-day intervals for 3 years reveals that the accuracy of prediction is more or less the same across all locations and time periods. Comparison of the results with f-ARIMA model predictions shows that the deterministic models with suitable parameters are capable of returning improved prediction accuracy and capturing the dynamical variations of the actual time series more faithfully. These methods are simple and computationally efficient and require only records of past data for making short-term wind speed forecasts within practically tolerable margin of errors.

  16. The Actual Apollo 13 Prime Crew

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The actual Apollo 13 lunar landing mission prime crew from left to right are: Commander, James A. Lovell Jr., Command Module pilot, John L. Swigert Jr.and Lunar Module pilot, Fred W. Haise Jr. The original Command Module pilot for this mission was Thomas 'Ken' Mattingly Jr. but due to exposure to German measles he was replaced by his backup, Command Module pilot, John L. 'Jack' Swigert Jr.

  17. Research on the processing technology of low-altitude unmanned aerial vehicle images

    NASA Astrophysics Data System (ADS)

    Tang, Shihua; Liu, Yintao; Li, Feida; Zhou, Conglin; Huang, Qing; Xu, Hongwei

    2015-12-01

    The UAV system acts as one of the infrastructure of earth observation, with its mobility, high speed, flexibility, economy and other remarkable technical advantages, has been widely used in various fields of the national economic construction, such as agricultural monitoring, resource development, disaster emergency treatment. Taking an actual engineering as a case study in this paper, the method and the skill of making digital orthophoto map was stated by using the UASMaster, the professional UAV data processing software, based on the eBee unmanned aerial vehicle. Finally, the precision of the DOM was analyzed in detail through two methods, overlapping the DOM with the existing DLG of the region and contrasting the points of the existing DLG of 1:1000 scale with the corresponding checkpoints of the stereomodel.

  18. Development of on-road emission factors from heavy-duty diesel vehicles using a continuous sampling system. Report for October 1994--September 1995

    SciTech Connect

    Harris, D.B.; King, F.G.; Brown, E.

    1998-12-31

    The purpose of the test program is to improve the existing conversion procedures for relating engine dynamometer tests in the laboratory to actual on-road emissions and to evaluate new modal approaches to estimate these emissions. The objectives of this project are to: (1) define on-road emissions from HDDVs; (2) assess agreement among engine and chassis dynamometers and on-road emission factors; (3) evaluate current conversion factors for dynamometer data and develop appropriate ones if needed; and (4) develop a modal emissions model that relates highway facility type (including grade) to speeds/accelerations of the vehicle, loaded weight, power demand on the vehicle, and emissions of NOx, CO, and VOCs.

  19. High-speed Imaging of Global Surface Temperature Distributions on Hypersonic Ballistic-Range Projectiles

    NASA Technical Reports Server (NTRS)

    Wilder, Michael C.; Reda, Daniel C.

    2004-01-01

    The NASA-Ames ballistic range provides a unique capability for aerothermodynamic testing of configurations in hypersonic, real-gas, free-flight environments. The facility can closely simulate conditions at any point along practically any trajectory of interest experienced by a spacecraft entering an atmosphere. Sub-scale models of blunt atmospheric entry vehicles are accelerated by a two-stage light-gas gun to speeds as high as 20 times the speed of sound to fly ballistic trajectories through an 24 m long vacuum-rated test section. The test-section pressure (effective altitude), the launch velocity of the model (flight Mach number), and the test-section working gas (planetary atmosphere) are independently variable. The model travels at hypersonic speeds through a quiescent test gas, creating a strong bow-shock wave and real-gas effects that closely match conditions achieved during actual atmospheric entry. The challenge with ballistic range experiments is to obtain quantitative surface measurements from a model traveling at hypersonic speeds. The models are relatively small (less than 3.8 cm in diameter), which limits the spatial resolution possible with surface mounted sensors. Furthermore, since the model is in flight, surface-mounted sensors require some form of on-board telemetry, which must survive the massive acceleration loads experienced during launch (up to 500,000 gravities). Finally, the model and any on-board instrumentation will be destroyed at the terminal wall of the range. For these reasons, optical measurement techniques are the most practical means of acquiring data. High-speed thermal imaging has been employed in the Ames ballistic range to measure global surface temperature distributions and to visualize the onset of transition to turbulent-flow on the forward regions of hypersonic blunt bodies. Both visible wavelength and infrared high-speed cameras are in use. The visible wavelength cameras are intensified CCD imagers capable of integration

  20. 49 CFR 213.345 - Vehicle/track system qualification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... operating speed. For purposes of qualification testing, speeds may exceed the maximum allowable operating... of wheel/rail forces during qualification testing shall demonstrate that the vehicle type will not..., qualification testing conducted over a representative segment of the route shall demonstrate that the...

  1. Vision-Based Leader Vehicle Trajectory Tracking for Multiple Agricultural Vehicles.

    PubMed

    Zhang, Linhuan; Ahamed, Tofael; Zhang, Yan; Gao, Pengbo; Takigawa, Tomohiro

    2016-04-22

    The aim of this study was to design a navigation system composed of a human-controlled leader vehicle and a follower vehicle. The follower vehicle automatically tracks the leader vehicle. With such a system, a human driver can control two vehicles efficiently in agricultural operations. The tracking system was developed for the leader and the follower vehicle, and control of the follower was performed using a camera vision system. A stable and accurate monocular vision-based sensing system was designed, consisting of a camera and rectangular markers. Noise in the data acquisition was reduced by using the least-squares method. A feedback control algorithm was used to allow the follower vehicle to track the trajectory of the leader vehicle. A proportional-integral-derivative (PID) controller was introduced to maintain the required distance between the leader and the follower vehicle. Field experiments were conducted to evaluate the sensing and tracking performances of the leader-follower system while the leader vehicle was driven at an average speed of 0.3 m/s. In the case of linear trajectory tracking, the RMS errors were 6.5 cm, 8.9 cm and 16.4 cm for straight, turning and zigzag paths, respectively. Again, for parallel trajectory tracking, the root mean square (RMS) errors were found to be 7.1 cm, 14.6 cm and 14.0 cm for straight, turning and zigzag paths, respectively. The navigation performances indicated that the autonomous follower vehicle was able to follow the leader vehicle, and the tracking accuracy was found to be satisfactory. Therefore, the developed leader-follower system can be implemented for the harvesting of grains, using a combine as the leader and an unloader as the autonomous follower vehicle.

  2. Vision-Based Leader Vehicle Trajectory Tracking for Multiple Agricultural Vehicles

    PubMed Central

    Zhang, Linhuan; Ahamed, Tofael; Zhang, Yan; Gao, Pengbo; Takigawa, Tomohiro

    2016-01-01

    The aim of this study was to design a navigation system composed of a human-controlled leader vehicle and a follower vehicle. The follower vehicle automatically tracks the leader vehicle. With such a system, a human driver can control two vehicles efficiently in agricultural operations. The tracking system was developed for the leader and the follower vehicle, and control of the follower was performed using a camera vision system. A stable and accurate monocular vision-based sensing system was designed, consisting of a camera and rectangular markers. Noise in the data acquisition was reduced by using the least-squares method. A feedback control algorithm was used to allow the follower vehicle to track the trajectory of the leader vehicle. A proportional–integral–derivative (PID) controller was introduced to maintain the required distance between the leader and the follower vehicle. Field experiments were conducted to evaluate the sensing and tracking performances of the leader-follower system while the leader vehicle was driven at an average speed of 0.3 m/s. In the case of linear trajectory tracking, the RMS errors were 6.5 cm, 8.9 cm and 16.4 cm for straight, turning and zigzag paths, respectively. Again, for parallel trajectory tracking, the root mean square (RMS) errors were found to be 7.1 cm, 14.6 cm and 14.0 cm for straight, turning and zigzag paths, respectively. The navigation performances indicated that the autonomous follower vehicle was able to follow the leader vehicle, and the tracking accuracy was found to be satisfactory. Therefore, the developed leader-follower system can be implemented for the harvesting of grains, using a combine as the leader and an unloader as the autonomous follower vehicle. PMID:27110793

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  4. Pioneer Launch on Delta Vehicle

    NASA Technical Reports Server (NTRS)

    1969-01-01

    NASA launches the last in the series of interplanetary Pioneer spacecraft, Pioneer 10 from Cape Kennedy, Florida. The long-tank Delta launch vehicle placed the spacecraft in a solar orbit along the path of Earth's orbit. The spacecraft then passed inside and outside Earth's orbit, alternately speeding up and slowing down relative to Earth. The Delta launch vehicle family started development in 1959. The Delta was composed of parts from the Thor, an intermediate-range ballistic missile, as its first stage, and the Vanguard as its second. The first Delta was launched from Cape Canaveral on May 13, 1960 and was powerful enough to deliver a 100-pound spacecraft into geostationary transfer orbit. Delta has been used to launch civil, commercial, and military satellites into orbit. For more information about Delta, please see Chapter 3 in Roger Launius and Dennis Jenkins' book To Reach the High Frontier published by The University Press of Kentucky in 2002.

  5. Vehicle/engine integration. [orbit transfer vehicles

    NASA Technical Reports Server (NTRS)

    Cooper, L. P.; Vinopal, T. J.; Florence, D. E.; Michel, R. W.; Brown, J. R.; Bergeron, R. P.; Weldon, V. A.

    1984-01-01

    VEHICLE/ENGINE Integration Issues are explored for orbit transfer vehicles (OTV's). The impact of space basing and aeroassist on VEHICLE/ENGINE integration is discussed. The AOTV structure and thermal protection subsystem weights were scaled as the vehicle length and surface was changed. It is concluded that for increased allowable payload lengths in a ground-based system, lower length-to-diameter (L/D) is as important as higher mixture ration (MR) in the range of mid L/D ATOV's. Scenario validity, geometry constraints, throttle levels, reliability, and servicing are discussed in the context of engine design and engine/vehicle integration.

  6. Vehicle Transponder for Preemption of Traffic Lights

    NASA Technical Reports Server (NTRS)

    Foster, Conrad; Bachelder, Aaron

    2006-01-01

    The purpose of this article is to describe, in more detail, the transponder installed in each vehicle that participates in the emergency traffic-light-preemption system described in the immediately preceding article. The transponder (see figure) is a fully autonomous data--collection, data-processing, information-display, and communication subsystem that performs robustly in preemption of traffic lights and monitoring of the statuses of street intersections. This transponder monitors the condition of the emergency vehicle in which it is installed and determines when the vehicle has been placed in an emergency-response condition with its siren and/or warning lights activated. Upon detection of such a condition, the transponder collects real-time velocity and acceleration data from the onboard diagnostic (OBD) computer of the vehicle. For this purpose, the transponder contains an OBD interface circuit, including a microprocessor that determines the manufacturer and model of the vehicle and then sends the appropriate commands to the OBD computer requesting the speed and acceleration data. At the same time, data from an onboard navigation system are collected to determine the location and the heading of the vehicle. Then acceleration, speed, position, and heading data are processed and combined with a vehicle-identification number and the resulting set of data is transmitted to monitoring and control units located at all intersections within communication range. When the unit at an intersection determines that this vehicle is approaching and has priority to preempt the intersection, it transmits a signal declaring the priority and the preemption to all participating vehicles (including this one) in the vicinity. If the unit at the intersection has determined that other participating vehicles are also approaching the intersection, then this unit also transmits, to the vehicle that has priority, a message that the other vehicles are approaching the same intersection. The

  7. High speed maglev design

    DOEpatents

    Rote, Donald M.; He, Jianliang; Coffey, Howard

    1993-01-01

    A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes dividing the superconducting magnets into two types: a strong field magnet which is located vertically below the vehicle for propulsion and guidance and a weak field superconducting magnet located at the ends of the vehicle for levitation and added guidance. Several proposed embodiments exist for the placement of the magnetic field shielding: locating the shielding on the vehicle, locating the shielding on the guideway, and locating the shielding on the guideway and adding shielding to the vertical undercarriage. In addition, the separation between the vehicle and the guideway can be controlled to reduce the exposure of the passenger cabin to magnetic fields.

  8. High speed maglev design

    DOEpatents

    Rote, D.M.; Jianliang He; Coffey, H.

    1993-10-19

    A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes dividing the superconducting magnets into two types: a strong field magnet which is located vertically below the vehicle for propulsion and guidance and a weak field superconducting magnet located at the ends of the vehicle for levitation and added guidance. Several proposed embodiments exist for the placement of the magnetic field shielding: locating the shielding on the vehicle, locating the shielding on the guideway, and locating the shielding on the guideway and adding shielding to the vertical undercarriage. In addition, the separation between the vehicle and the guideway can be controlled to reduce the exposure of the passenger cabin to magnetic fields. 4 figures.

  9. Exploring stop-go decision zones at rural high-speed intersections with flashing green signal and insufficient yellow time in China.

    PubMed

    Tang, Keshuang; Xu, Yanqing; Wang, Fen; Oguchi, Takashi

    2016-10-01

    The objective of this study is to empirically analyze and model the stop-go decision behavior of drivers at rural high-speed intersections in China, where a flashing green signal of 3s followed by a yellow signal of 3s is commonly applied to end a green phase. 1, 186 high-resolution vehicle trajectories were collected at four typical high-speed intersection approaches in Shanghai and used for the identification of actual stop-go decision zones and the modeling of stop-go decision behavior. Results indicate that the presence of flashing green significantly changed the theoretical decision zones based on the conventional Dilemma Zone theory. The actual stop-go decision zones at the study intersections were thus formulated and identified based on the empirical data. Binary Logistic model and Fuzzy Logic model were then developed to further explore the impacts of flashing green on the stop-go behavior of drivers. It was found that the Fuzzy Logic model could produce comparably good estimation results as compared to the traditional Binary Logistic models. The findings of this study could contribute the development of effective dilemma zone protection strategies, the improvement of stop-go decision model embedded in the microscopic traffic simulation software and the proper design of signal change and clearance intervals at high-speed intersections in China.

  10. Naturalistic speeding data: Drivers aged 75 years and older.

    PubMed

    Chevalier, Anna; Chevalier, Aran John; Clarke, Elizabeth; Wall, John; Coxon, Kristy; Brown, Julie; Ivers, Rebecca; Keay, Lisa

    2016-09-01

    The data presented in this article are related to the research article entitled "A longitudinal investigation of the predictors of older drivers׳ speeding behavior" (Chevalier et al., 2016) [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75-94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS) data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control.

  11. Peer Influence Predicts Speeding Prevalence Among Teenage Drivers

    PubMed Central

    Ouimet, Marie Claude; Chen, Rusan; Klauer, Sheila G.; Lee, Suzanne E.; Wang, Jing; Dingus, Thomas A.

    2012-01-01

    Objective This research examined the psychosocial and personality predictors of observed speeding among young drivers. Method. Survey and driving data were collected from 42 newly-licensed teenage drivers during the first 18 months of licensure. Speeding (i.e., driving 10 mph over the speed limit; about 16 km/h) was assessed by comparing speed data collected with recording systems installed in participants’ vehicles with posted speed limits. Questionnaire data collected at baseline were used to predict speeding rates using random effects regression analyses. For mediation analysis, data collected at baseline and at 6, 12, and 18 months after licensure were used. Results. Speeding was correlated with elevated g-force event rates, including hard braking and turning (r = 0.335, p < 0.05), but not with crashes and near crashes (r = 0.227; ns). Speeding prevalence increased over time. In univariate analyses speeding was predicted by day vs. night trips, higher sensation seeking, substance use, tolerance of deviance, susceptibility to peer pressure, and number of risky friends. In multivariate analyses the number of risky friends was the only significant predictor of speeding. Perceived risk was a significant mediator of the association between speeding and risky friends. Conclusion. The findings support the contention that social norms may influence teenage speeding behavior and this relationship may operate through perceived risk. PMID:23206513

  12. Design and development of single-stage-to-orbit vehicles

    NASA Astrophysics Data System (ADS)

    Billig, Frederick S.

    1990-12-01

    A procedure to guide the conceptual design of a single-stage-to-orbit vehicle is presented. Modeling based on historical databases is used to help define plausible flight trajectories and vehicle aerodynamics and to evaluate candidate propulsion cycles. Two conceptual configurations are introduced to examine the sensitivity of vehicle drag, engine cycle selection, and design characteristics on the amount of propelant required to accelerate to orbit. Results show that the choice of the optimum low-speed engine cycle, combined with the ram-scramjet (supersonic combustion ramjet) at high speed, is very sensitive to the engine air capture and vehicle drag coefficient at transonic speeds. For nominal drag and air capture characteristics, the high thrust and relatively low-efficiency ducted rocket/ram-scramjet cycle uses about the same weight of propellant as the highly efficient but lower-thrust turbojet ram-scramjet.

  13. Automated mixed traffic vehicle design AMTV 2

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

    The design of an improved and enclosed Automated Mixed Traffic Transit (AMTT) vehicle is described. AMTT is an innovative concept for low-speed tram-type transit in which suitable vehicles are equipped with sensors and controls to permit them to operate in an automated mode on existing road or walkway surfaces. The vehicle chassis and body design are presented in terms of sketches and photographs. The functional design of the sensing and control system is presented, and modifications which could be made to the baseline design for improved performance, in particular to incorporate a 20-mph capability, are also discussed. The vehicle system is described at the block-diagram-level of detail. Specifications and parameter values are given where available.

  14. Vertical Landing Aerodynamics of Reusable Rocket Vehicle

    NASA Astrophysics Data System (ADS)

    Nonaka, Satoshi; Nishida, Hiroyuki; Kato, Hiroyuki; Ogawa, Hiroyuki; Inatani, Yoshifumi

    The aerodynamic characteristics of a vertical landing rocket are affected by its engine plume in the landing phase. The influences of interaction of the engine plume with the freestream around the vehicle on the aerodynamic characteristics are studied experimentally aiming to realize safe landing of the vertical landing rocket. The aerodynamic forces and surface pressure distributions are measured using a scaled model of a reusable rocket vehicle in low-speed wind tunnels. The flow field around the vehicle model is visualized using the particle image velocimetry (PIV) method. Results show that the aerodynamic characteristics, such as the drag force and pitching moment, are strongly affected by the change in the base pressure distributions and reattachment of a separation flow around the vehicle.

  15. High speed machining of space shuttle external tank liquid hydrogen barrel panel

    NASA Technical Reports Server (NTRS)

    Hankins, J. D.

    1983-01-01

    Actual and projected optimum High Speed Machining data for producing shuttle external tank liquid hydrogen barrel panels of aluminum alloy 2219-T87 are reported. The data included various machining parameters; e.g., spindle speeds, cutting speed, table feed, chip load, metal removal rate, horsepower, cutting efficiency, cutter wear (lack of) and chip removal methods.

  16. Intelligent Advisory Speed Limit Dedication in Highway Using VANET

    PubMed Central

    Md Noor, Rafidah; Yeo, Hwasoo; Jung, Jason J.

    2014-01-01

    Variable speed limits (VSLs) as a mean for enhancing road traffic safety are studied for decades to modify the speed limit based on the prevailing road circumstances. In this study the pros and cons of VSL systems and their effects on traffic controlling efficiency are summarized. Despite the potential effectiveness of utilizing VSLs, we have witnessed that the effectiveness of this system is impacted by factors such as VSL control strategy used and the level of driver compliance. Hence, the proposed approach called Intelligent Advisory Speed Limit Dedication (IASLD) as the novel VSL control strategy which considers the driver compliance aims to improve the traffic flow and occupancy of vehicles in addition to amelioration of vehicle's travel times. The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle's characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions. The proposed approach takes advantage of vehicular ad hoc network (VANET) to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy. The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions. PMID:24999493

  17. Intelligent advisory speed limit dedication in highway using VANET.

    PubMed

    Jalooli, Ali; Shaghaghi, Erfan; Jabbarpour, Mohammad Reza; Noor, Rafidah Md; Yeo, Hwasoo; Jung, Jason J

    2014-01-01

    Variable speed limits (VSLs) as a mean for enhancing road traffic safety are studied for decades to modify the speed limit based on the prevailing road circumstances. In this study the pros and cons of VSL systems and their effects on traffic controlling efficiency are summarized. Despite the potential effectiveness of utilizing VSLs, we have witnessed that the effectiveness of this system is impacted by factors such as VSL control strategy used and the level of driver compliance. Hence, the proposed approach called Intelligent Advisory Speed Limit Dedication (IASLD) as the novel VSL control strategy which considers the driver compliance aims to improve the traffic flow and occupancy of vehicles in addition to amelioration of vehicle's travel times. The IASLD provides the advisory speed limit for each vehicle exclusively based on the vehicle's characteristics including the vehicle type, size, and safety capabilities as well as traffic and weather conditions. The proposed approach takes advantage of vehicular ad hoc network (VANET) to accelerate its performance, in the way that simulation results demonstrate the reduction of incident detection time up to 31.2% in comparison with traditional VSL strategy. The simulation results similarly indicate the improvement of traffic flow efficiency, occupancy, and travel time in different conditions.

  18. Development of a DC propulsion system for an electric vehicle

    NASA Technical Reports Server (NTRS)

    Kelledes, W. L.

    1984-01-01

    The suitability of the Eaton automatically shifted mechanical transaxle concept for use in a near-term dc powered electric vehicle is evaluated. A prototype dc propulsion system for a passenger electric vehicle was designed, fabricated, tested, installed in a modified Mercury Lynx vehicle and track tested at the contractor's site. The system consisted of a two-axis, three-speed, automatically-shifted mechanical transaxle, 15.2 Kw rated, separately excited traction motor, and a transistorized motor controller with a single chopper providing limited armature current below motor base speed and full range field control above base speed at up to twice rated motor current. The controller utilized a microprocessor to perform motor and vehicle speed monitoring and shift sequencing by means of solenoids applying hydraulic pressure to the transaxle clutches. Bench dynamometer and track testing was performed. Track testing showed best system efficiency for steady-state cruising speeds of 65-80 Km/Hz (40-50 mph). Test results include acceleration, steady speed and SAE J227A/D cycle energy consumption, braking tests and coast down to characterize the vehicle road load.

  19. Explosive Percolation Transition is Actually Continuous

    NASA Astrophysics Data System (ADS)

    da Costa, R. A.; Dorogovtsev, S. N.; Goltsev, A. V.; Mendes, J. F. F.

    2010-12-01

    Recently a discontinuous percolation transition was reported in a new “explosive percolation” problem for irreversible systems [D. Achlioptas, R. M. D’Souza, and J. Spencer, Science 323, 1453 (2009)SCIEAS0036-807510.1126/science.1167782] in striking contrast to ordinary percolation. We consider a representative model which shows that the explosive percolation transition is actually a continuous, second order phase transition though with a uniquely small critical exponent of the percolation cluster size. We describe the unusual scaling properties of this transition and find its critical exponents and dimensions.

  20. Neoadjuvant Treatment in Rectal Cancer: Actual Status

    PubMed Central

    Garajová, Ingrid; Di Girolamo, Stefania; de Rosa, Francesco; Corbelli, Jody; Agostini, Valentina; Biasco, Guido; Brandi, Giovanni

    2011-01-01

    Neoadjuvant (preoperative) concomitant chemoradiotherapy (CRT) has become a standard treatment of locally advanced rectal adenocarcinomas. The clinical stages II (cT3-4, N0, M0) and III (cT1-4, N+, M0) according to International Union Against Cancer (IUCC) are concerned. It can reduce tumor volume and subsequently lead to an increase in complete resections (R0 resections), shows less toxicity, and improves local control rate. The aim of this review is to summarize actual approaches, main problems, and discrepancies in the treatment of locally advanced rectal adenocarcinomas. PMID:22295206

  1. Air resistance measurements on actual airplane parts

    NASA Technical Reports Server (NTRS)

    Weiselsberger, C

    1923-01-01

    For the calculation of the parasite resistance of an airplane, a knowledge of the resistance of the individual structural and accessory parts is necessary. The most reliable basis for this is given by tests with actual airplane parts at airspeeds which occur in practice. The data given here relate to the landing gear of a Siemanms-Schuckert DI airplane; the landing gear of a 'Luftfahrzeug-Gesellschaft' airplane (type Roland Dlla); landing gear of a 'Flugzeugbau Friedrichshafen' G airplane; a machine gun, and the exhaust manifold of a 269 HP engine.

  2. Nissan Hypermini Urban Electric Vehicle Testing

    SciTech Connect

    James Francfort; Robert Brayer

    2006-01-01

    The U.S. Department of Energy’s (DOE’s) Advanced Vehicle Testing Activity (AVTA), which is part of DOE’s FreedomCAR and Vehicle Technologies Program, in partnership with the California cities of Vacaville and Palm Springs, collected mileage and maintenance and repairs data for a fleet of eleven Nissan Hypermini urban electric vehicles (UEVs). The eleven Hyperminis were deployed for various periods between January 2001 and June 2005. During the combined total of 439 months of use, the eleven Hyperminis were driven a total of 41,220 miles by staff from both cities. This equates to an average use of about 22 miles per week per vehicle. There were some early problems with the vehicles, including a charging problem and a need to upgrade the electrical system. In addition, six vehicles required drive system repairs. However, the repairs were all made under warranty. The Hyperminis were generally well-liked and provided drivers with the ability to travel any of the local roads. Full charging of the Hypermini’s lithiumion battery pack required up to 4 hours, with about 8–10 miles of range available for each hour of battery charging. With its right-side steering wheel, some accommodation of the drivers’ customary driving methods was required to adapt for different blind spots and vehicle manipulation. For that reason, the drivers received orientation and training before using the vehicle. The Hypermini is instrumented in kilometers rather than in miles, which required an adjustment for the drivers to calculate speed and range. As the drivers gained familiarity with the vehicles, there was increased acceptance and a preference for using it over traditional city vehicles. In all cases, the Hyperminis attracted a great amount of attention and interest from the general public.

  3. Feasibility study on linear-motor-assisted take-off (LMATO) of winged launch vehicle

    NASA Astrophysics Data System (ADS)

    Nagatomo, Makoto; Kyotani, Yoshihiro

    1987-11-01

    Application of technology of magnetically levitated transportation to horizontal take-off of an experimental space vehicle has been studied. An experimental system of linear-motor-assisted take-off (LMATO) consists of the HIMES space vehicle and a magnetically levitated and propelled sled which is a modified MLU model developed by the JNR. The original MLU model is a train of three cars which weighs 30 tons and is driven by a thrust of 15 tons. The maximum speed is 400 km/h. The highest speed of 517 km/h has been obtained by the first JNR linear motor car. Since the take-off speed of the HIMES vehicle with the initial mass of 14 tons is 470 km/h, the existing technology can be used for the LMATO of the vehicle. The concept of the HIMES/LMATO is to use the MLU vehicles to accelerate the HIMES vehicle at 0.33 g on a 5 km guide track until the speed reaches 300 km/h, when the rocket engines of the space vehicle are started to increase the acceleration up to 1 g. The total system will take the final checkout for take-off during the acceleration phase and the speed exceeds 470 km/h which is large enough to aerodynamically lift the space vehicle, then the fastening mechanism is unlocked to separate the vehicles. The experimental system can be applied for initial acceleration of a vehicle with air-breathing propulsion.

  4. High-speed Oil Engines for Vehicles. Part II

    NASA Technical Reports Server (NTRS)

    Hausfelder, Ludwig

    1927-01-01

    Further progress toward the satisfactory solution of the difficult problem of the distribution and atomization of the injected fuel was made by extensive experimentation with various fuel valves, nozzles, and atomizing devices. Valuable information was also obtained through numerous experimental researches on the combustion of oils and the manner of introducing the combustion air into the cylinder, as well as on the physical processes of atomization, the determination of the size of drops, etc. These researches led to the conclusion that it is possible, even without producing great turbulence in the combustion chamber and at moderate pump pressure, if the degree of atomization and the penetrative power of the fuel jet are adapted to the shape of the combustion chamber and to the dimensions of the cylinder.

  5. A scaled roller test rig for high-speed vehicles

    NASA Astrophysics Data System (ADS)

    Allotta, Benedetto; Pugi, Luca; Malvezzi, Monica; Bartolini, Fabio; Cangioli, Francesco

    2010-12-01

    Scaled roller rigs are quite widespread among railway research centres, and several examples are described in the literature. Due to their low costs and ease of use compared with full-scale counterparts, these types of rigs are used for a wide range of studies concerning dynamical stability, comfort, mechatronic subsystem and wear. Furthermore, scaled roller rigs can be a powerful education tool for railway engineering students. In this paper, the design and the main features of the scaled rolled rig that will be installed in the Mechatronics and Dynamic Modeling Laboratory of the University of Florence located in Pistoia, Italy, are described. The main feature of the proposed rig will be the simulation of degraded adhesion conditions. This feature is very important for hardware-in-the loop testing of many safety relevant on-board subsystems like wheel slide protection systems, traction and stability controls, odometry and automatic train protection and control.

  6. Mobility-Dependent Motion Planning for High Speed Robotic Vehicles

    DTIC Science & Technology

    2008-07-25

    constraints and measures of optimality. As a consequence, many results from the theory of optimal controL in particular, those that guarantee time optimalitY1... Control Systen1s 1 pages 1-12, 2004. R Goebel and A.R Teel. Solutions to hybrid inclusions via set and graphical convergence with stability theory ... Control , pages 410-415, 1999. [11j 1. S. Pontryagin, V. G. Boltyanskij, R V. Gamkrelidze 1 and E. F. 1VIishchenko. The mathematical theory of optimal

  7. 40 CFR 86.153-98 - Vehicle and canister preconditioning; refueling test.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... fixed-speed fan specified in § 86.135-94(b) may be used for engine cooling. If a fixed-speed fan is used, the vehicle's hood shall be opened. (ii) Alternatively, the roadspeed-modulated fan specified in § 86.107-96(d)(1) may be used for engine cooling. If a road-speed modulated fan is used, the vehicle's...

  8. Bendix Lunar Roving Vehicle (LRV) Test Article

    NASA Technical Reports Server (NTRS)

    1966-01-01

    An engineer demonstrates a Mobility Test Article (MTA) at NASA's Marshall Space Flight Center (MSFC) as he crosses a soft clay strip onto rocky ground. This unit, weighing 1/6th as much as an actual vehicle, was built by the Bendix Corporation and was one of the concepts of a possible Lunar Roving Vehicle (LRV). The data provided by the MTA helped in designing the LRV, developed under the direction of MSFC. The LRV was designed to allow Apollo astronauts a greater range of mobility during lunar exploration missions.

  9. Vehicle test report: Jet Industries Electra Van 600

    NASA Technical Reports Server (NTRS)

    Price, T. W.; Wirth, V. A., Jr.

    1982-01-01

    The Electra Van 600, an electric vehicle, was tested. Tests were performed to characterize parameters of the Electra Van 600 and to provide baseline data to be used for comparison of improved batteries and to which will be incorporated into the vehicle. The vehicle tests concentrated on the electrical drive subsystem, the batteries, controller, and motor; coastdowns to characterize the road load and range evaluation for cyclic and constant speed conditions; and qualitative performance was evaluated. It is found that the Electra Van 600 range performance is approximately equal to the majority of the vehicles tested previously.

  10. High speed handpieces

    PubMed Central

    Bhandary, Nayan; Desai, Asavari; Shetty, Y Bharath

    2014-01-01

    High speed instruments are versatile instruments used by clinicians of all specialties of dentistry. It is important for clinicians to understand the types of high speed handpieces available and the mechanism of working. The centers for disease control and prevention have issued guidelines time and again for disinfection and sterilization of high speed handpieces. This article presents the recent developments in the design of the high speed handpieces. With a view to prevent hospital associated infections significant importance has been given to disinfection, sterilization & maintenance of high speed handpieces. How to cite the article: Bhandary N, Desai A, Shetty YB. High speed handpieces. J Int Oral Health 2014;6(1):130-2. PMID:24653618

  11. Variable current speed controller for eddy current motors

    DOEpatents

    Gerth, H.L.; Bailey, J.M.; Casstevens, J.M.; Dixon, J.H.; Griffith, B.O.; Igou, R.E.

    1982-03-12

    A speed control system for eddy current motors is provided in which the current to the motor from a constant frequency power source is varied by comparing the actual motor speed signal with a setpoint speed signal to control the motor speed according to the selected setpoint speed. A three-phase variable voltage autotransformer is provided for controlling the voltage from a three-phase power supply. A corresponding plurality of current control resistors is provided in series with each phase of the autotransformer output connected to inputs of a three-phase motor. Each resistor is connected in parallel with a set of normally closed contacts of plurality of relays which are operated by control logic. A logic circuit compares the selected speed with the actual motor speed obtained from a digital tachometer monitoring the motor spindle speed and operated the relays to add or substract resistance equally in each phase of the motor input to vary the motor current to control the motor at the selected speed.

  12. Thermoregulation during prolonged actual and laboratory-simulated bicycling.

    PubMed

    Brown, S L; Banister, E W

    1985-01-01

    Thermoregulatory and cardiorespiratory responses to bicycling 55 km (mean speed 9.7 m X s-1) outdoors (15 degrees C DB) were compared to equivalent cycle ergometry (90 min at 65% VO2max) in the laboratory (20-23 degrees C DB, 50% RH) in 7 trained cyclists. Outdoor environmental conditions were simulated with fans and lamps, and were contrasted with standard no-wind, no-sun laboratory conditions. Sweating rate was similar during outdoor and laboratory simulated outdoor cycling (0.90 and 0.87 to 0.94 1 X h-1 respectively). During outdoor bicycling, mean heart rate (161 bt X min-1) was 7-13% higher (p less than .05) than under laboratory conditions, suggesting a greater strain for a similar external work rate. The increase in rectal temperature (0.8 degrees C) was 33-50% less (p less than 0.05) at the cooler outdoor ambient temperature than in the laboratory. Thermoregulatory stress was greater under the no-fan, no-lamp laboratory condition than during simulated outdoor conditions (36-38% greater (p less than 0.05) sweating rate, 15-18% greater (p less than 0.01) mean skin temperature, 6.4 to 7.8 fold greater (p less than 0.01) amount of clothing-retrained sweat). The cooling wind encountered in actual road bicycling apparently reduces thermoregulatory and circulatory demands compared with stationary cycle ergometry indoors. Failure to account for this enhanced cooling may result in overestimation of the physiological stress of actual road cycling.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Concepts for Variable/Multi-Speed Rotorcraft Drive System

    NASA Technical Reports Server (NTRS)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2008-01-01

    In several recent studies and on-going developments for advanced rotorcraft, the need for variable or multi-speed capable rotors has been raised. A speed change of up to 50 percent has been proposed for future rotorcraft to improve overall vehicle performance. Accomplishing rotor speed changes during operation requires both a rotor that can perform effectively over the operation speed/load range, and a propulsion system that can enable these speed changes. A study has been completed to investigate possible drive system arrangements that can accommodate up to the 50 percent speed change. Several concepts will be presented and evaluated. The most promising configurations will be identified and developed for future testing in a sub-scaled test facility to validate operational capability.

  14. High-Speed, high-power, switching transistor

    NASA Technical Reports Server (NTRS)

    Carnahan, D.; Ohu, C. K.; Hower, P. L.

    1979-01-01

    Silicon transistor rate for 200 angstroms at 400 to 600 volts combines switching speed of transistors with ruggedness, power capacity of thyristor. Transistor introduces unique combination of increased power-handling capability, unusally low saturation and switching losses, and submicrosecond switching speeds. Potential applications include high power switching regulators, linear amplifiers, chopper controls for high frequency electrical vehicle drives, VLF transmitters, RF induction heaters, kitchen cooking ranges, and electronic scalpels for medical surgery.

  15. HEAVY DUTY DIESEL VEHICLE LOAD ESTIMATION: DEVELOPMENT OF VEHICLE ACTIVITY OPTIMIZATION ALGORITHM

    EPA Science Inventory

    The Heavy-Duty Vehicle Modal Emission Model (HDDV-MEM) developed by the Georgia Institute of Technology(Georgia Tech) has a capability to model link-specific second-by-second emissions using speed/accleration matrices. To estimate emissions, engine power demand calculated usin...

  16. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  17. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  18. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  19. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  20. 7 CFR 1437.101 - Actual production history.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Actual production history. 1437.101 Section 1437.101... Determining Yield Coverage Using Actual Production History § 1437.101 Actual production history. Actual production history (APH) is the unit's record of crop yield by crop year for the APH base period. The...

  1. Motor vehicle deaths: failed policy analysis and neglected policy.

    PubMed

    Robertson, Leon S

    2006-07-01

    The author of a recent book inferred that the slowed decline in U.S. vehicle fatality rates in the 1990 s relative to other industrialized countries resulted from too much emphasis on vehicle factors. He claimed that Canada had the same vehicle mix but a lower fatality rate. Actually, U.S. death rates by make and model applied to Canadian vehicle sales indicates that Canada's death rate would be the same as the U.S. if Canada had the same vehicle mix and annual miles driven. The U.S. had much greater growth in sales of large SUVs and pickup trucks that are heavier and stiffer than passenger cars, contributing to excess deaths of other road users in collisions. They are also more unstable, contributing to excess deaths of their occupants in rollovers. Lack of policy regarding these vehicle characteristics is the primary reason for the attenuated decline in vehicular fatality rates.

  2. The price of commitment in online stochastic vehicle routing

    SciTech Connect

    Bent, Russell W; Van Hentenryck, Pascal

    2009-01-01

    This paper considers online stochastic multiple vehicle routing with time windows in which requests arrive dynamically and the goal is to maximize the number of serviced customers. Early work has focused on very flexible routing settings where the decision to assign a vehicle to a customer is delayed until a vehicle is actually deployed to the customer. Motivated by real applications that require stability in the decision making, this paper considers a setting where the decision to assign a customer request to a vehicle must be taken when that request is accepted. Experimental results suggest that this constraint severely degrades the performance of existing algorithms. However, the paper shows how the use of stochastic information for vehicle assignment and request acceptance improves decision quality considerably. Moreover, the use of resource augmentation quantifies precisely the cost of commitment in online vehicle routing.

  3. Comparative costs and benefits of hydrogen vehicles

    SciTech Connect

    Berry, G.D.

    1996-10-01

    The costs and benefits of hydrogen as a vehicle fuel are compared to gasoline, natural gas, and battery-powered vehicles. Costs, energy, efficiency, and tail-pipe and full fuel cycle emissions of air pollutants and greenhouse gases were estimated for hydrogen from a broad range of delivery pathways and scales: from individual vehicle refueling systems to large stations refueling 300 cars/day. Hydrogen production from natural gas, methanol, and ammonia, as well as water electrolysis based on alkaline or polymer electrolytes and steam electrolysis using solid oxide electrolytes are considered. These estimates were compared to estimates for competing fuels and vehicles, and used to construct oil use, air pollutant, and greenhouse gas emission scenarios for the U.S. passenger car fleet from 2005-2050. Fuel costs need not be an overriding concern in evaluating the suitability of hydrogen as a fuel for passenger vehicles. The combined emissions and oil import reduction benefits of hydrogen cars are estimated to be significant, valued at up to {approximately}$400/yr for each hydrogen car when primarily clean energy sources are used for hydrogen production. These benefits alone, however, become tenuous as the basis supporting a compelling rationale for hydrogen fueled vehicles, if efficient, advanced fossil-fuel hybrid electric vehicles (HEV`s) can achieve actual on-road emissions at or below ULEV standards in the 2005-2015 timeframe. It appears a robust rationale for hydrogen fuel and vehicles will need to also consider unique, strategic, and long-range benefits of hydrogen vehicles which can be achieved through the use of production, storage, delivery, and utilization methods for hydrogen which are unique among fuels: efficient use of intermittent renewable energy sources, (e,g, wind, solar), small-scale feasibility, fuel production at or near the point of use, electrolytic production, diverse storage technologies, and electrochemical conversion to electricity.

  4. Advanced Technology Vehicle Testing

    SciTech Connect

    James Francfort

    2003-11-01

    The light-duty vehicle transportation sector in the United States depends heavily on imported petroleum as a transportation fuel. The Department of Energy’s Advanced Vehicle Testing Activity (AVTA) is testing advanced technology vehicles to help reduce this dependency, which would contribute to the economic stability and homeland security of the United States. These advanced technology test vehicles include internal combustion engine vehicles operating on 100% hydrogen (H2) and H2CNG (compressed natural gas) blended fuels, hybrid electric vehicles, neighborhood electric vehicles, urban electric vehicles, and electric ground support vehicles. The AVTA tests and evaluates these vehicles with closed track and dynamometer testing methods (baseline performance testing) and accelerated reliability testing methods (accumulating lifecycle vehicle miles and operational knowledge within 1 to 1.5 years), and in normal fleet environments. The Arizona Public Service Alternative Fuel Pilot Plant and H2-fueled vehicles are demonstrating the feasibility of using H2 as a transportation fuel. Hybrid, neighborhood, and urban electric test vehicles are demonstrating successful applications of electric drive vehicles in various fleet missions. The AVTA is also developing electric ground support equipment (GSE) test procedures, and GSE testing will start during the fall of 2003. All of these activities are intended to support U.S. energy independence. The Idaho National Engineering and Environmental Laboratory manages these activities for the AVTA.

  5. The actual status of Astronomy in Moldova

    NASA Astrophysics Data System (ADS)

    Gaina, A.

    The astronomical research in the Republic of Moldova after Nicolae Donitch (Donici)(1874-1956(?)) were renewed in 1957, when a satellites observations station was open in Chisinau. Fotometric observations and rotations of first Soviet artificial satellites were investigated under a program SPIN put in action by the Academy of Sciences of former Socialist Countries. The works were conducted by Assoc. prof. Dr. V. Grigorevskij, which conducted also research in variable stars. Later, at the beginning of 60-th, an astronomical Observatory at the Chisinau State University named after Lenin (actually: the State University of Moldova), placed in Lozovo-Ciuciuleni villages was open, which were coordinated by Odessa State University (Prof. V.P. Tsesevich) and the Astrosovet of the USSR. Two main groups worked in this area: first conducted by V. Grigorevskij (till 1971) and second conducted by L.I. Shakun (till 1988), both graduated from Odessa State University. Besides this research areas another astronomical observations were made: Comets observations, astroclimate and atmospheric optics in collaboration with the Institute of the Atmospheric optics of the Siberian branch of the USSR (V. Chernobai, I. Nacu, C. Usov and A.F. Poiata). Comets observations were also made since 1988 by D. I. Gorodetskij which came to Chisinau from Alma-Ata and collaborated with Ukrainean astronomers conducted by K.I. Churyumov. Another part of space research was made at the State University of Tiraspol since the beggining of 70-th by a group of teaching staff of the Tiraspol State Pedagogical University: M.D. Polanuer, V.S. Sholokhov. No a collaboration between Moldovan astronomers and Transdniestrian ones actually exist due to War in Transdniestria in 1992. An important area of research concerned the Radiophysics of the Ionosphere, which was conducted in Beltsy at the Beltsy State Pedagogical Institute by a group of teaching staff of the University since the beginning of 70-th: N. D. Filip, E

  6. Pedestrian crashes: higher injury severity and mortality rate for light truck vehicles compared with passenger vehicles

    PubMed Central

    Roudsari, B; Mock, C; Kaufman, R; Grossman, D; Henary, B; Crandall, J

    2004-01-01

    Introduction: During the last two decades changes in vehicle design and increase in the number of the light truck vehicles (LTVs) and vans have led to changes in pedestrian injury profile. Due to the dynamic nature of the pedestrian crashes biomechanical aspects of collisions can be better evaluated in field studies. Design and settings: The Pedestrian Crash Data Study, conducted from 1994 to 1998, provided a solid database upon which details and mechanism of pedestrian crashes can be investigated. Results: From 552 recorded cases in this database, 542 patients had complete injury related information, making a meaningful study of pedestrian crash characteristics possible. Pedestrians struck by LTVs had a higher risk (29%) of severe injuries (abbreviated injury scale ⩾4) compared with passenger vehicles (18%) (p = 0.02). After adjustment for pedestrian age and impact speed, LTVs were associated with 3.0 times higher risk of severe injuries (95% confidence interval (CI) 1.26 to 7.29, p = 0.013). Mortality rate for pedestrians struck by LTVs (25%) was two times higher than that for passenger vehicles (12%) (p<0.001). Risk of death for LTV crashes after adjustment for pedestrian age and impact speed was 3.4 times higher than that for passenger vehicles (95% CI 1.45 to 7.81, p = 0.005). Conclusion: Vehicle type strongly influences risk of severe injury and death to pedestrian. This may be due in part to the front end design of the vehicle. Hence vehicle front end design, especially for LTVs, should be considered in future motor vehicle safety standards. PMID:15178671

  7. System Analyses of Pneumatic Technology for High Speed Civil Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Mavris, Dimitri N.; Tai, Jimmy C.; Kirby, Michelle M.; Roth, Bryce A.

    1999-01-01

    The primary aspiration of this study was to objectively assess the feasibility of the application of a low speed pneumatic technology, in particular Circulation Control (CC) to an HSCT concept. Circulation Control has been chosen as an enabling technology to be applied on a generic High Speed Civil Transport (HSCT). This technology has been proven for various subsonic vehicles including flight tests on a Navy A-6 and computational application on a Boeing 737. Yet, CC has not been widely accepted for general commercial fixed-wing use but its potential has been extensively investigated for decades in wind tunnels across the globe for application to rotorcraft. More recently, an experimental investigation was performed at Georgia Tech Research Institute (GTRI) with application to an HSCT-type configuration. The data from those experiments was to be applied to a full-scale vehicle to assess the impact from a system level point of view. Hence, this study attempted to quantitatively assess the impact of this technology to an HSCT. The study objective was achieved in three primary steps: 1) Defining the need for CC technology; 2) Wind tunnel data reduction; 3) Detailed takeoff/landing performance assessment. Defining the need for the CC technology application to an HSCT encompassed a preliminary system level analysis. This was accomplished through the utilization of recent developments in modern aircraft design theory at Aerospace Systems Design Laboratory (ASDL). These developments include the creation of techniques and methods needed for the identification of technical feasibility show stoppers. These techniques and methods allow the designer to rapidly assess a design space and disciplinary metric enhancements to enlarge or improve the design space. The takeoff and landing field lengths were identified as the concept "show-stoppers". Once the need for CC was established, the actual application of data and trends was assessed. This assessment entailed a reduction of the

  8. Secondary lift for magnetically levitated vehicles

    DOEpatents

    Cooper, Richard K.

    1976-01-01

    A high-speed terrestrial vehicle that is magnetically levitated by means of magnets which are used to induce eddy currents in a continuous electrically conductive nonferromagnetic track to produce magnetic images that repel the inducing magnet to provide primary lift for the vehicle. The magnets are arranged so that adjacent ones have their fields in opposite directions and the magnets are spaced apart a distance that provides a secondary lift between each magnet and the adjacent magnet's image, the secondary lift being maximized by optimal spacing of the magnets.

  9. Student Program for Environmental Excellence in Design (SPEED) Grant - Closed Announcement FY 2015

    EPA Pesticide Factsheets

    SPEED aims to increase students’ awareness and understanding of the environmental benefits stemming from increasing fuel efficiency, reducing carbon intensity in transportation fuels, and reducing emissions in advanced vehicles.

  10. Student Program for Environmental Excellence in Design (SPEED) Grant - Closed Announcement FY 2014

    EPA Pesticide Factsheets

    SPEED aims to increase students’ awareness and understanding of the environmental benefits stemming from increasing fuel efficiency, reducing carbon intensity in transportation fuels, and reducing emissions in advanced vehicles.

  11. Orbital Transfer Vehicle Engine Technology High Velocity Ratio Diffusing Crossover

    NASA Technical Reports Server (NTRS)

    Lariviere, Brian W.

    1992-01-01

    High speed, high efficiency head rise multistage pumps require continuous passage diffusing crossovers to effectively convey the pumped fluid from the exit of one impeller to the inlet of the next impeller. On Rocketdyne's Orbital Transfer Vehicle (OTV), the MK49-F, a three stage high pressure liquid hydrogen turbopump, utilizes a 6.23 velocity ratio diffusing crossover. This velocity ratio approaches the diffusion limits for stable and efficient flow over the operating conditions required by the OTV system. The design of the high velocity ratio diffusing crossover was based on advanced analytical techniques anchored by previous tests of stationary two-dimensional diffusers with steady flow. To secure the design and the analytical techniques, tests were required with the unsteady whirling characteristics produced by an impeller. A tester was designed and fabricated using a 2.85 times scale model of the MK49-F turbopumps first stage, including the inducer, impeller, and the diffusing crossover. Water and air tests were completed to evaluate the large scale turbulence, non-uniform velocity, and non-steady velocity on the pump and crossover head and efficiency. Suction performance tests from 80 percent to 124 percent of design flow were completed in water to assess these pump characteristics. Pump and diffuser performance from the water and air tests were compared with the actual MK49-F test data in liquid hydrogen.

  12. Orbital transfer vehicle engine technology high velocity ratio diffusing crossover

    NASA Astrophysics Data System (ADS)

    Lariviere, Brian W.

    1992-12-01

    High speed, high efficiency head rise multistage pumps require continuous passage diffusing crossovers to effectively convey the pumped fluid from the exit of one impeller to the inlet of the next impeller. On Rocketdyne's Orbital Transfer Vehicle (OTV), the MK49-F, a three stage high pressure liquid hydrogen turbopump, utilizes a 6.23 velocity ratio diffusing crossover. This velocity ratio approaches the diffusion limits for stable and efficient flow over the operating conditions required by the OTV system. The design of the high velocity ratio diffusing crossover was based on advanced analytical techniques anchored by previous tests of stationary two-dimensional diffusers with steady flow. To secure the design and the analytical techniques, tests were required with the unsteady whirling characteristics produced by an impeller. A tester was designed and fabricated using a 2.85 times scale model of the MK49-F turbopumps first stage, including the inducer, impeller, and the diffusing crossover. Water and air tests were completed to evaluate the large scale turbulence, non-uniform velocity, and non-steady velocity on the pump and crossover head and efficiency. Suction performance tests from 80 percent to 124 percent of design flow were completed in water to assess these pump characteristics. Pump and diffuser performance from the water and air tests were compared with the actual MK49-F test data in liquid hydrogen.

  13. Vehicle transmission having countershaft and planetary portions

    SciTech Connect

    Nerstad, K.A.; Windish, W.E.

    1986-09-30

    This patent describes a vehicle transmission comprising: a countershaft transmission including an input first shaft, a second shaft, an output third shaft, gears operatively associated with the shafts, a reversing idler gear cooperatively engaging two of the gears, and low, high, and reverse clutch assembly means for selectively connecting the gears in a preselected manner. The reverse clutch assembly provides either one of two forward speeds and one reverse speed at the third shaft, the low and high clutch assembly means being disposed generally along the second shaft; and a planetary transmission serially driven by the third shaft and including interconnected planetary gear sets and brake assembly means for selectively actuating one of the planetary gear sets and providing one speed for use with each speed of the countershaft transmission.

  14. Consumer Views on Transportation and Advanced Vehicle Technologies

    SciTech Connect

    Singer, Mark

    2015-09-01

    Vehicle manufacturers, U.S. Department of Energy laboratories, universities, private researchers, and organizations from countries around the globe are pursuing advanced vehicle technologies that aim to reduce gasoline and diesel consumption. This report details study findings of broad American public sentiments toward issues surrounding advanced vehicle technologies and is supported by the U.S. Department of Energy Vehicle Technology Office (VTO) in alignment with its mission to develop and deploy these technologies to improve energy security, increase mobility flexibility, reduce transportation costs, and increase environmental sustainability. Understanding and tracking consumer sentiments can influence the prioritization of development efforts by identifying barriers to and opportunities for broad acceptance of new technologies. Predicting consumer behavior toward developing technologies and products is inherently inexact. A person's stated preference given in an interview about a hypothetical setting may not match the preference that is demonstrated in an actual situation. This difference makes tracking actual consumer actions ultimately more valuable in understanding potential behavior. However, when developing technologies are not yet available and actual behaviors cannot be tracked, stated preferences provide some insight into how consumers may react in new circumstances. In this context this report provides an additional source to validate data and a new resource when no data are available. This report covers study data captured from December 2005 through June 2015 relevant to VTO research efforts at the time of the studies. Broadly the report covers respondent sentiments about vehicle fuel economy, future vehicle technology alternatives, ethanol as a vehicle fuel, plug-in electric vehicles, and willingness to pay for vehicle efficiency. This report represents a renewed effort to publicize study findings and make consumer sentiment data available to

  15. Method and system for determining induction motor speed

    DOEpatents

    Parlos, Alexander G.; Bharadwaj, Raj M.

    2004-03-30

    A non-linear, semi-parametric neural network-based adaptive filter is utilized to determine the dynamic speed of a rotating rotor within an induction motor, without the explicit use of a speed sensor, such as a tachometer, is disclosed. The neural network-based filter is developed using actual motor current measurements, voltage measurements, and nameplate information. The neural network-based adaptive filter is trained using an estimated speed calculator derived from the actual current and voltage measurements. The neural network-based adaptive filter uses voltage and current measurements to determine the instantaneous speed of a rotating rotor. The neural network-based adaptive filter also includes an on-line adaptation scheme that permits the filter to be readily adapted for new operating conditions during operations.

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

    NASA Astrophysics Data System (ADS)

    Hua, Yiding; Jiang, Haobin; Geng, Guoqing

    2017-03-01

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

  17. Passive Earth Entry Vehicle Landing Test

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris

    2017-01-01

    Two full-scale passive Earth Entry Vehicles (EEV) with realistic structure, surrogate sample container, and surrogate Thermal Protection System (TPS) were built at NASA Langley Research Center (LaRC) and tested at the Utah Test and Training Range (UTTR). The main test objective was to demonstrate structural integrity and investigate possible impact response deviations of the realistic vehicle as compared to rigid penetrometer responses. With the exception of the surrogate TPS and minor structural differences in the back shell construction, the two test vehicles were identical in geometry and both utilized the Integrated Composite Stiffener Structure (ICoSS) structural concept in the forward shell. The ICoSS concept is a lightweight and highly adaptable composite concept developed at NASA LaRC specifically for entry vehicle TPS carrier structures. The instrumented test vehicles were released from a helicopter approximately 400 m above ground. The drop height was selected such that at least 98% of the vehicles terminal velocity would be achieved. While drop tests of spherical penetrometers and a low fidelity aerodynamic EEV model were conducted at UTTR in 1998 and 2000, this was the first time a passive EEV with flight-like structure, surrogate TPS, and sample container was tested at UTTR for the purpose of complete structural system validation. Test results showed that at a landing vertical speed of approximately 30 m/s, the test vehicle maintained structural integrity and enough rigidity to penetrate the sandy clay surface thus attenuating the landing load, as measured at the vehicle CG, to less than 600 g. This measured deceleration was found to be in family with rigid penetrometer test data from the 1998 and 2000 test campaigns. Design implications of vehicle structure/soil interaction with respect to sample container and sample survivability are briefly discussed.

  18. Path duplication using GPS carrier based relative position for automated ground vehicle convoys

    NASA Astrophysics Data System (ADS)

    Travis, William E., III

    use of this method is limited to short following distances, or line of sight operation, similar to vision based following approaches. The following vehicle turns about a smaller radius than the lead vehicle, and this effect intensifies as following distance increases. The second path duplication method allows for non line of sight operation by combining the vector odometry with the relative position to create a virtual leader to follow. The actual difference between the vehicles could be in excess of 100 meters, but the perceived distance is reduced to a predetermined value based on vehicle speed by re-generating the lead vehicle's position at a previous instance in time with the relative position and odometry information. Performance curves of path duplication accuracy versus following distance using different odometry techniques show that the partially integrated tactical unit provides the best performance, but the time differenced carrier approach offered very similar performance for a lower total system cost. Both following methods were implemented on an unmanned ground vehicle. Tests showed following accuracy for the line of sight method was within 50 centimeters on straight sections, though the reference accuracy was centimeter level. The non line of sight method predicted the virtual leader position to within 5 centimeters for following distances ranging from 10 to 120 meters.

  19. Mobility planning for omnidirectional vehicles in natural terrains

    NASA Astrophysics Data System (ADS)

    Goodsell, Thomas G.; Flann, Nicholas S.; Davidson, Morgan E.

    1999-07-01

    Planning paths for omni-directional vehicles (ODVs) can be computationally infeasible because of the large space of possible paths. This paper presents an approach that avoids this problem through the use of abstraction in characterizing the possible maneuvers of the ODV as a grammar of parameterized mobility behaviors and describing the terrain as a covering of object-oriented functional terrain features. The terrain features contain knowledge on how best to create mobility paths -- sequences of mobility behaviors -- through the object. Given an approximate map of the environment, the approach constructs a graph of mobility paths that link the location of the vehicle with the goals. The actual paths followed by the vehicle are determined by an A* search through the graph. The effectiveness of the strategy is demonstrated in actual tests with a real robotic vehicle.

  20. Caustic-Side Solvent Extraction: Prediction of Cesium Extraction for Actual Wastes and Actual Waste Simulants

    SciTech Connect

    Delmau, L.H.; Haverlock, T.J.; Sloop, F.V., Jr.; Moyer, B.A.

    2003-02-01

    This report presents the work that followed the CSSX model development completed in FY2002. The developed cesium and potassium extraction model was based on extraction data obtained from simple aqueous media. It was tested to ensure the validity of the prediction for the cesium extraction from actual waste. Compositions of the actual tank waste were obtained from the Savannah River Site personnel and were used to prepare defined simulants and to predict cesium distribution ratios using the model. It was therefore possible to compare the cesium distribution ratios obtained from the actual waste, the simulant, and the predicted values. It was determined that the predicted values agree with the measured values for the simulants. Predicted values also agreed, with three exceptions, with measured values for the tank wastes. Discrepancies were attributed in part to the uncertainty in the cation/anion balance in the actual waste composition, but likely more so to the uncertainty in the potassium concentration in the waste, given the demonstrated large competing effect of this metal on cesium extraction. It was demonstrated that the upper limit for the potassium concentration in the feed ought to not exceed 0.05 M in order to maintain suitable cesium distribution ratios.

  1. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Handling of Placarded Rail Cars, Transport Vehicles and Freight Containers § 174.86 Maximum allowable operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in...) for shipments by rail. (b) For trains transporting any loaded, placarded tank cars containing...

  2. 49 CFR 174.86 - Maximum allowable operating speed.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Handling of Placarded Rail Cars, Transport Vehicles and Freight Containers § 174.86 Maximum allowable operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in...) for shipments by rail. (b) For trains transporting any loaded, placarded tank cars containing...

  3. Regular and homeward travel speeds of arctic wolves

    USGS Publications Warehouse

    Mech, L.D.

    1994-01-01

    Single wolves (Canis lupus arctos), a pair, and a pack of five habituated to the investigator on an all-terrain vehicle were followed on Ellesmere Island, Northwest Territories, Canada, during summer. Their mean travel speed was measured on barren ground at 8.7 km/h during regular travel and 10.0 km/h when returning to a den.

  4. Tutorial on Actual Space Environmental Hazards For Space Systems (Invited)

    NASA Astrophysics Data System (ADS)

    Mazur, J. E.; Fennell, J. F.; Guild, T. B.; O'Brien, T. P.

    2013-12-01

    It has become common in the space science community to conduct research on diverse physical phenomena because they are thought to contribute to space weather. However, satellites contend with only three primary environmental hazards: single event effects, vehicle charging, and total dose, and not every physical phenomenon that occurs in space contributes in substantial ways to create these hazards. One consequence of the mismatch between actual threats and all-encompassing research is the often-described gap between research and operations; another is the creation of forecasts that provide no actionable information for design engineers or spacecraft operators. An example of the latter is the physics of magnetic field emergence on the Sun; the phenomenon is relevant to the formation and launch of coronal mass ejections and is also causally related to the solar energetic particles that may get accelerated in the interplanetary shock. Unfortunately for the research community, the engineering community mitigates the space weather threat (single-event effects from heavy ions above ~50 MeV/nucleon) with a worst-case specification of the environment and not with a prediction. Worst-case definition requires data mining of past events, while predictions involve large-scale systems science from the Sun to the Earth that is compelling for scientists and their funding agencies but not actionable for design or for most operations. Differing priorities among different space-faring organizations only compounds the confusion over what science research is relevant. Solar particle impacts to human crew arise mainly from the total ionizing dose from the solar protons, so the priority for prediction in the human spaceflight community is therefore much different than in the unmanned satellite community, while both communities refer to the fundamental phenomenon as space weather. Our goal in this paper is the presentation of a brief tutorial on the primary space environmental phenomena

  5. Powertrain system for a hybrid electric vehicle

    DOEpatents

    Reed, R.G. Jr.; Boberg, E.S.; Lawrie, R.E.; Castaing, F.J.

    1999-08-31

    A hybrid electric powertrain system is provided including an electric motor/generator drivingly engaged with the drive shaft of a transmission. The electric is utilized for synchronizing the rotation of the drive shaft with the driven shaft during gear shift operations. In addition, a mild hybrid concept is provided which utilizes a smaller electric motor than typical hybrid powertrain systems. Because the electric motor is drivingly engaged with the drive shaft of the transmission, the electric motor/generator is driven at high speed even when the vehicle speed is low so that the electric motor/generator provides more efficient regeneration. 34 figs.

  6. Powertrain system for a hybrid electric vehicle

    DOEpatents

    Reed, Jr., Richard G.; Boberg, Evan S.; Lawrie, Robert E.; Castaing, Francois J.

    1999-08-31

    A hybrid electric powertrain system is provided including an electric motor/generator drivingly engaged with the drive shaft of a transmission. The electric is utilized for synchronizing the rotation of the drive shaft with the driven shaft during gear shift operations. In addition, a mild hybrid concept is provided which utilizes a smaller electric motor than typical hybrid powertrain systems. Because the electric motor is drivingly engaged with the drive shaft of the transmission, the electric motor/generator is driven at high speed even when the vehicle speed is low so that the electric motor/generator provides more efficient regeneration.

  7. Technology needs for high-speed rotorcraft

    NASA Technical Reports Server (NTRS)

    Rutherford, John; Orourke, Matthew; Martin, Christopher; Lovenguth, Marc; Mitchell, Clark

    1991-01-01

    A study to determine the technology development required for high-speed rotorcraft development was conducted. The study begins with an initial assessment of six concepts capable of flight at, or greater than 450 knots with helicopter-like hover efficiency (disk loading less than 50 pfs). These concepts were sized and evaluated based on measures of effectiveness and operational considerations. Additionally, an initial assessment of the impact of technology advances on the vehicles attributes was made. From these initial concepts a tilt wing and rotor/wing concepts were selected for further evaluation. A more detailed examination of conversion and technology trade studies were conducted on these two vehicles, each sized for a different mission.

  8. High speed civil transport aerodynamic optimization

    NASA Technical Reports Server (NTRS)

    Ryan, James S.

    1994-01-01

    This is a report of work in support of the Computational Aerosciences (CAS) element of the Federal HPCC program. Specifically, CFD and aerodynamic optimization are being performed on parallel computers. The long-range goal of this work is to facilitate teraflops-rate multidisciplinary optimization of aerospace vehicles. This year's work is targeted for application to the High Speed Civil Transport (HSCT), one of four CAS grand challenges identified in the HPCC FY 1995 Blue Book. This vehicle is to be a passenger aircraft, with the promise of cutting overseas flight time by more than half. To meet fuel economy, operational costs, environmental impact, noise production, and range requirements, improved design tools are required, and these tools must eventually integrate optimization, external aerodynamics, propulsion, structures, heat transfer, controls, and perhaps other disciplines. The fundamental goal of this project is to contribute to improved design tools for U.S. industry, and thus to the nation's economic competitiveness.

  9. Evaluation of an expedient terrorist vehicle barrier

    SciTech Connect

    McCallen, D; Lewis, P; Wattenburg, B; Mote, P

    2000-02-28

    The threat of terrorist vehicle bombs has become evident in the past few years. The explosive power that can be generated by a ''home made'' bomb carried by a standard van or moderate size truck can generate sufficient blast overpressures to cause major damage or catastrophic collapse to building structures. There are a number of means available to help prevent a successful terrorist attack on a facility. One measure consists of the gathering of intelligence that can be used to thwart an attack before it takes place. The design and retrofit of structures and structural systems which can resist blast loadings and protect occupants is another area which is currently receiving a great deal of attention by the security community. Another measure, which can be used to protect many existing facilities, is to restrict access to the facility. This option consists of keeping unauthorized vehicles as far as possible from the facility so that if a vehicle bomb does approach the facility, the distance at which the bomb is detonated will result in significant reduction in the overpressures by the time the blast wave reaches the protected structure. This paper describes a simple and efficient vehicle barrier concept that can be used to prevent unauthorized vehicle access. The feasibility study described herein consisted of a field experimental program to test the validity of the barrier concept, and demonstrated the ability of the simple barrier to effectively disable speeding vehicles.

  10. Actual Versus Estimated Utility Factor of a Large Set of Privately Owned Chevrolet Volts

    SciTech Connect

    John Smart; Thomas Bradley; Stephen Schey

    2014-04-01

    In order to determine the overall fuel economy of a plug-in hybrid electric vehicle (PHEV), the amount of operation in charge depleting (CD) versus charge sustaining modes must be determined. Mode of operation is predominantly dependent on customer usage of the vehicle and is therefore highly variable. The utility factor (UF) concept was developed to quantify the distance a group of vehicles has traveled or may travel in CD mode. SAE J2841 presents a UF calculation method based on data collected from travel surveys of conventional vehicles. UF estimates have been used in a variety of areas, including the calculation of window sticker fuel economy, policy decisions, and vehicle design determination. The EV Project, a plug-in electric vehicle charging infrastructure demonstration being conducted across the United States, provides the opportunity to determine the real-world UF of a large group of privately owned Chevrolet Volt extended range electric vehicles. Using data collected from Volts enrolled in The EV Project, this paper compares the real-world UF of two groups of Chevrolet Volts to estimated UF's based on J2841. The actual observed fleet utility factors (FUF) for the MY2011/2012 and MY2013 Volt groups studied were observed to be 72% and 74%, respectively. Using the EPA CD ranges, the method prescribed by J2841 estimates a FUF of 65% and 68% for the MY2011/2012 and MY2013 Volt groups, respectively. Volt drivers achieved higher percentages of distance traveled in EV mode for two reasons. First, they had fewer long-distance travel days than drivers in the national travel survey referenced by J2841. Second, they charged more frequently than the J2841 assumption of once per day - drivers of Volts in this study averaged over 1.4 charging events per day. Although actual CD range varied widely as driving conditions varied, the average CD ranges for the two Volt groups studied matched the EPA CD range estimates, so CD range variation did not affect FUF results.

  11. Shaft speed control

    NASA Technical Reports Server (NTRS)

    Ford, A. G.

    1979-01-01

    Simple mechanism controls rotation of heavy-duty shaft by mechanical comparison with rotation of small, precise, stepper motor. Mechanism can be used to limit winding and unwinding speeds of large spools and reels and to control speed of other rotating shafts. Setup incorporates reference shaft geared down from stepper motor and feedback shaft geared up from shaft to be controlled. Feedback and reference shafts are coupled with brake assembly inside stationary cylinder. When work shaft speeds up, brakes are activated automatically to slow it down.

  12. Energy 101: Electric Vehicles

    SciTech Connect

    2012-01-01

    This edition of Energy 101 highlights the benefits of electric vehicles, including improved fuel efficiency, reduced emissions, and lower maintenance costs. For more information on electric vehicles from the Office of Energy Efficiency and Renewable Energy, visit the Vehicle Technologies Program website: http://www1.eere.energy.gov/vehiclesandfuels/

  13. MRV - Modular Robotic Vehicle

    NASA Technical Reports Server (NTRS)

    Ridley, Justin; Bluethmann, Bill

    2015-01-01

    The Modular Robotic Vehicle, or MRV, completed in 2013, was developed at the Johnson Space Center in order to advance technologies which have applications for future vehicles both in space and on Earth. With seating for two people, MRV is a fully electric vehicle modeled as a "city car", suited for busy urban environments.

  14. Electric vehicles: Driving range

    NASA Astrophysics Data System (ADS)

    Kempton, Willett

    2016-09-01

    For uptake of electric vehicles to increase, consumers' driving-range needs must be fulfilled. Analysis of the driving patterns of personal vehicles in the US now shows that today's electric vehicles can meet all travel needs on almost 90% of days from a single overnight charge.

  15. Energy 101: Electric Vehicles

    ScienceCinema

    None

    2016-07-12

    This edition of Energy 101 highlights the benefits of electric vehicles, including improved fuel efficiency, reduced emissions, and lower maintenance costs. For more information on electric vehicles from the Office of Energy Efficiency and Renewable Energy, visit the Vehicle Technologies Program website: http://www1.eere.energy.gov/vehiclesandfuels/

  16. Electric Vehicle Technician

    ERIC Educational Resources Information Center

    Moore, Pam

    2011-01-01

    With President Obama's goal to have one million electric vehicles (EV) on the road by 2015, the electric vehicle technician should have a promising and busy future. "The job force in the car industry is ramping up for a revitalized green car industry," according to Greencareersguide.com. An electric vehicle technician will safely troubleshoot and…

  17. Automotive vehicle sensors

    SciTech Connect

    Sheen, S.H.; Raptis, A.C.; Moscynski, M.J.

    1995-09-01

    This report is an introduction to the field of automotive vehicle sensors. It contains a prototype data base for companies working in automotive vehicle sensors, as well as a prototype data base for automotive vehicle sensors. A market analysis is also included.

  18. Solar space vehicle

    SciTech Connect

    Lee, R.E.

    1982-10-19

    This invention relates to space vehicle where solar energy is used to generate steam, which in turn, propels the vehicle in space. A copper boiler is provided and a novel solar radiation condensing means is used to focus the sunlight on said boiler. Steam generated in said boiler is exhausted to the environment to provide a thrust for the vehicle.

  19. Transformable descent vehicles

    NASA Astrophysics Data System (ADS)

    Pichkhadze, K. M.; Finchenko, V. S.; Aleksashkin, S. N.; Ostreshko, B. A.

    2016-12-01

    This article presents some types of planetary descent vehicles, the shape of which varies in different flight phases. The advantages of such vehicles over those with unchangeable form (from launch to landing) are discussed. It is shown that the use of transformable descent vehicles widens the scope of possible tasks to solve.

  20. 40 CFR 85.2220 - Preconditioned two speed idle test-EPA 91.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) Second-chance high-speed mode—(i) Ford Motor Company and Honda vehicles. The engines of 1981-1987 model year Ford Motor Company vehicles and 1984-1985 model year Honda Preludes must be shut off for not more than ten seconds and then restarted. The probe may be removed from the tailpipe or the sample...

  1. 36 CFR 1192.175 - High-speed rail cars, monorails and systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... steel-wheel-on-steel-rail technology, and monorail systems operating primarily on dedicated rail (i.e..., monorails and systems. 1192.175 Section 1192.175 Parks, Forests, and Public Property ARCHITECTURAL AND... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.175 High-speed rail cars, monorails and systems....

  2. 40 CFR 85.2215 - Two speed idle test-EPA 91.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... vehicles the OBD data link connector will be used to monitor RPM. In the event that an OBD data link... shall be used instead. (iii) The sample probe is inserted into the vehicle's tailpipe to a minimum depth... described under paragraphs (c)(2) (ii) and (iii) of this section. The maximum high-speed mode length is...

  3. 40 CFR 85.2215 - Two speed idle test-EPA 91.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... vehicles the OBD data link connector will be used to monitor RPM. In the event that an OBD data link... shall be used instead. (iii) The sample probe is inserted into the vehicle's tailpipe to a minimum depth... described under paragraphs (c)(2) (ii) and (iii) of this section. The maximum high-speed mode length is...

  4. 40 CFR 85.2215 - Two speed idle test-EPA 91.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... vehicles the OBD data link connector will be used to monitor RPM. In the event that an OBD data link... shall be used instead. (iii) The sample probe is inserted into the vehicle's tailpipe to a minimum depth... described under paragraphs (c)(2) (ii) and (iii) of this section. The maximum high-speed mode length is...

  5. Modeling, Robust Control, and Experimental Validation of a Supercavitating Vehicle

    NASA Astrophysics Data System (ADS)

    Escobar Sanabria, David

    This dissertation considers the mathematical modeling, control under uncertainty, and experimental validation of an underwater supercavitating vehicle. By traveling inside a gas cavity, a supercavitating vehicle reduces hydrodynamic drag, increases speed, and minimizes power consumption. The attainable speed and power efficiency make these vehicles attractive for undersea exploration, high-speed transportation, and defense. However, the benefits of traveling inside a cavity come with difficulties in controlling the vehicle dynamics. The main challenge is the nonlinear force that arises when the back-end of the vehicle pierces the cavity. This force, referred to as planing, leads to oscillatory motion and instability. Control technologies that are robust to planing and suited for practical implementation need to be developed. To enable these technologies, a low-order vehicle model that accounts for inaccuracy in the characterization of planing is required. Additionally, an experimental method to evaluate possible pitfalls in the models and controllers is necessary before undersea testing. The major contribution of this dissertation is a unified framework for mathematical modeling, robust control synthesis, and experimental validation of a supercavitating vehicle. First, we introduce affordable experimental methods for mathematical modeling and controller testing under planing and realistic flow conditions. Then, using experimental observations and physical principles, we create a low-order nonlinear model of the longitudinal vehicle motion. This model quantifies the planing uncertainty and is suitable for robust controller synthesis. Next, based on the vehicle model, we develop automated tools for synthesizing controllers that deliver a certificate of performance in the face of nonlinear and uncertain planing forces. We demonstrate theoretically and experimentally that the proposed controllers ensure higher performance when the uncertain planing dynamics are

  6. Vehicle safety telemetry for automated highways

    NASA Technical Reports Server (NTRS)

    Hansen, G. R.

    1977-01-01

    The emphasis in current, automatic vehicle testing and diagnosis is primarily centered on the proper operation of the engine. Lateral and longitudinal guidance technologies, including speed control and headway sensing for collision avoidance, are reviewed. The principal guidance technique remains the buried wire. Speed control and headway sensing, even though they show the same basic elements in braking and fuel systems, are proceeding independently. The applications of on-board electronic and microprocessor techniques were investigated; each application (emission control, spark advance, or anti-slip braking) is being treated as an independent problem is proposed. A unified bus system of distributed processors for accomplishing the various functions and testing required for vehicles equipped to use automated highways.

  7. Automated mixed traffic transit vehicle microprocessor controller

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  8. Speeding earthquake disaster relief

    USGS Publications Warehouse

    Mortensen, Carl; Donlin, Carolyn; Page, Robert A.; Ward, Peter

    1995-01-01

    In coping with recent multibillion-dollar earthquake disasters, scientists and emergency managers have found new ways to speed and improve relief efforts. This progress is founded on the rapid availability of earthquake information from seismograph networks.

  9. Speed- Reading Made Easy

    ERIC Educational Resources Information Center

    Brown, W. S.

    1970-01-01

    Illustrates a compromise between vertical and horizontal typographies which should make speed reading faster and more reliable, and suggests that computers could prepare text according to this arrangement. (MB)

  10. High Speed Research Program

    NASA Technical Reports Server (NTRS)

    Anderson, Robert E.; Corsiglia, Victor R.; Schmitz, Frederic H. (Technical Monitor)

    1994-01-01

    An overview of the NASA High Speed Research Program will be presented from a NASA Headquarters perspective. The presentation will include the objectives of the program and an outline of major programmatic issues.

  11. High-Speed Photography

    SciTech Connect

    Paisley, D.L.; Schelev, M.Y.

    1998-08-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) {copyright} {ital 1998 Society of Photo-Optical Instrumentation Engineers.}

  12. Consequences of Predicted or Actual Asteroid Impacts

    NASA Astrophysics Data System (ADS)

    Chapman, C. R.

    2003-12-01

    Earth impact by an asteroid could have enormous physical and environmental consequences. Impactors larger than 2 km diameter could be so destructive as to threaten civilization. Since such events greatly exceed any other natural or man-made catastrophe, much extrapolation is necessary just to understand environmental implications (e.g. sudden global cooling, tsunami magnitude, toxic effects). Responses of vital elements of the ecosystem (e.g. agriculture) and of human society to such an impact are conjectural. For instance, response to the Blackout of 2003 was restrained, but response to 9/11 terrorism was arguably exaggerated and dysfunctional; would society be fragile or robust in the face of global catastrophe? Even small impacts, or predictions of impacts (accurate or faulty), could generate disproportionate responses, especially if news media reports are hyped or inaccurate or if responsible entities (e.g. military organizations in regions of conflict) are inadequately aware of the phenomenology of small impacts. Asteroid impact is the one geophysical hazard of high potential consequence with which we, fortunately, have essentially no historical experience. It is thus important that decision makers familiarize themselves with the hazard and that society (perhaps using a formal procedure, like a National Academy of Sciences study) evaluate the priority of addressing the hazard by (a) further telescopic searches for dangerous but still-undiscovered asteroids and (b) development of mitigation strategies (including deflection of an oncoming asteroid and on- Earth civil defense). I exemplify these issues by discussing several representative cases that span the range of parameters. Many of the specific physical consequences of impact involve effects like those of other geophysical disasters (flood, fire, earthquake, etc.), but the psychological and sociological aspects of predicted and actual impacts are distinctive. Standard economic cost/benefit analyses may not

  13. A Novel Vehicle Classification Using Embedded Strain Gauge Sensors.

    PubMed

    Zhang, Wenbin; Wang, Qi; Suo, Chunguang

    2008-11-05

    This paper presents a new vehicle classification and develops a traffic monitoring detector to provide reliable vehicle classification to aid traffic management systems. The basic principle of this approach is based on measuring the dynamic strain caused by vehicles across pavement to obtain the corresponding vehicle parameters - wheelbase and number of axles - to then accurately classify the vehicle. A system prototype with five embedded strain sensors was developed to validate the accuracy and effectiveness of the classification method. According to the special arrangement of the sensors and the different time a vehicle arrived at the sensors one can estimate the vehicle's speed accurately, corresponding to the estimated vehicle wheelbase and number of axles. Because of measurement errors and vehicle characteristics, there is a lot of overlap between vehicle wheelbase patterns. Therefore, directly setting up a fixed threshold for vehicle classification often leads to low-accuracy results. Using the machine learning pattern recognition method to deal with this problem is believed as one of the most effective tools. In this study, support vector machines (SVMs) were used to integrate the classification features extracted from the strain sensors to automatically classify vehicles into five types, ranging from small vehicles to combination trucks, along the lines of the Federal Highway Administration vehicle classification guide. Test bench and field experiments will be introduced in this paper. Two support vector machines classification algorithms (one-against-all, one-against-one) are used to classify single sensor data and multiple sensor combination data. Comparison of the two classification method results shows that the classification accuracy is very close using single data or multiple data. Our results indicate that using multiclass SVM-based fusion multiple sensor data significantly improves the results of a single sensor data, which is trained on the whole

  14. A Novel Vehicle Classification Using Embedded Strain Gauge Sensors

    PubMed Central

    Zhang, Wenbin; Wang, Qi; Suo, Chunguang

    2008-01-01

    This paper presents a new vehicle classification and develops a traffic monitoring detector to provide reliable vehicle classification to aid traffic management systems. The basic principle of this approach is based on measuring the dynamic strain caused by vehicles across pavement to obtain the corresponding vehicle parameters – wheelbase and number of axles – to then accurately classify the vehicle. A system prototype with five embedded strain sensors was developed to validate the accuracy and effectiveness of the classification method. According to the special arrangement of the sensors and the different time a vehicle arrived at the sensors one can estimate the vehicle's speed accurately, corresponding to the estimated vehicle wheelbase and number of axles. Because of measurement errors and vehicle characteristics, there is a lot of overlap between vehicle wheelbase patterns. Therefore, directly setting up a fixed threshold for vehicle classification often leads to low-accuracy results. Using the machine learning pattern recognition method to deal with this problem is believed as one of the most effective tools. In this study, support vector machines (SVMs) were used to integrate the classification features extracted from the strain sensors to automatically classify vehicles into five types, ranging from small vehicles to combination trucks, along the lines of the Federal Highway Administration vehicle classification guide. Test bench and field experiments will be introduced in this paper. Two support vector machines classification algorithms (one-against-all, one-against-one) are used to classify single sensor data and multiple sensor combination data. Comparison of the two classification method results shows that the classification accuracy is very close using single data or multiple data. Our results indicate that using multiclass SVM-based fusion multiple sensor data significantly improves the results of a single sensor data, which is trained on the

  15. Vehicle/engine integration

    NASA Astrophysics Data System (ADS)

    Cooper, L. P.; Vinopal, T. J.; Florence, D. E.; Michel, R. W.; Brown, J. R.; Bergeron, R. P.; Weldon, V. A.

    1984-04-01

    VEHICLE/ENGINE Integration Issues are explored for orbit transfer vehicles (OTV's). The impact of space basing and aeroassist on VEHICLE/ENGINE integration is discussed. The AOTV structure and thermal protection subsystem weights were scaled as the vehicle length and surface was changed. It is concluded that for increased allowable payload lengths in a ground-based system, lower length-to-diameter (L/D) is as important as higher mixture ration (MR) in the range of mid L/D ATOV's. Scenario validity, geometry constraints, throttle levels, reliability, and servicing are discussed in the context of engine design and engine/vehicle integration.

  16. VEHICLE FOR SLAVE ROBOT

    DOEpatents

    Goertz, R.C.; Lindberg, J.F.

    1962-01-30

    A reeling device is designed for an electrical cable supplying power to the slave slde of a remote control manipulator mounted on a movable vehicle. As the vehicle carries the slave side about in a closed room, the device reels the cable in and out to maintain a variable length of the cable between the vehicle and a cable inlet in the wall of the room. The device also handles a fixed length of cable between the slave side and the vehicle, in spite of angular movement of the slave side with respect to the vehicle. (AEC)

  17. Compact change speed transmission

    SciTech Connect

    Iwanaga, K.; Yamaguchi, T.

    1989-06-06

    A change speed transmission is described comprising: a stationary part; an input member; an output member; first and second planetary gear sets; clutch and brake means for selectively controlling the first and second planetary gear sets to provide a plurality of forward speed rations and a reverse speed ratio between the input and output member; the clutch and brake means including a first clutch, a first one-way clutch, and a second one-way clutch which, when the first clutch is engaged, provide a path of transmission of reaction to the stationary part thereby establishing a path of transmission of torque through at least a part of the first and second planetary gear sets to achieve a predetermined one speed ratio of the forward speed ratios; the clutch and brake means including also a brake and a second slutch which, when both of the brake and the second clutch are engaged, hinder the action of the second one-way clutch and that of the first one-way clutch, respectively, thereby providing engine braking during running with the predetermined one speed ratio; the first clutch including means forming a drum-shaped member disposed radially outwardly of and receiving at least one of the first and second planetary gear sets, and an actuating piston of the first clutch; and the second clutch including an actuating piston slidably disposed within the actuating piston of the first clutch.

  18. [Risk perception and speeding].

    PubMed

    Thielen, Iara Picchioni; Hartmann, Ricardo Carlos; Soares, Diogo Picchioni

    2008-01-01

    This paper discusses risk perception comparing drivers with and without fines for speeding. The research aimed to show the interaction between speeding laws and speeding behavior. Speeders' explanations for their behavior revealed important factors in the determination of risk perception: control (driver-centered), risk minimization (drivers claimed there was no risk involved in the way they speeded), self-confidence (they considered themselves good drivers and believed they were able to define what constitutes speeding), and lack of credibility in the institutions that manage traffic risks. Speeders display a cognitive construct of personal invulnerability combined with unrealistic optimism and overrated self-perception, along with an exaggerated perception of their control over the traffic setting, centered on their self-purported driving skills. No difference was found in risk perception between drivers in the two groups. There was no relationship between objective and perceived risks, since drivers from the two groups showed a generic perception of objective risks, but out-of-context in relation to the inherent potential for accidents at different speeds.

  19. High Speed Ice Friction

    NASA Astrophysics Data System (ADS)

    Seymour-Pierce, Alexandra; Sammonds, Peter; Lishman, Ben

    2014-05-01

    Many different tribological experiments have been run to determine the frictional behaviour of ice at high speeds, ostensibly with the intention of applying results to everyday fields such as winter tyres and sports. However, experiments have only been conducted up to linear speeds of several metres a second, with few additional subject specific studies reaching speeds comparable to these applications. Experiments were conducted in the cold rooms of the Rock and Ice Physics Laboratory, UCL, on a custom built rotational tribometer based on previous literature designs. Preliminary results from experiments run at 2m/s for ice temperatures of 271 and 263K indicate that colder ice has a higher coefficient of friction, in accordance with the literature. These results will be presented, along with data from further experiments conducted at temperatures between 259-273K (in order to cover a wide range of the temperature dependent behaviour of ice) and speeds of 2-15m/s to produce a temperature-velocity-friction map for ice. The effect of temperature, speed and slider geometry on the deformation of ice will also be investigated. These speeds are approaching those exhibited by sports such as the luge (where athletes slide downhill on an icy track), placing the tribological work in context.

  20. Advanced ac powertrain for electric vehicles

    SciTech Connect

    Slicker, J.M.; Kalns, L.

    1985-01-01

    The design of an ac propulsion system for an electric vehicle includes a three-phase induction motor, transistorized PWM inverter/battery charger, microprocessor-based controller, and two-speed automatic transaxle. This system was built and installed in a Mercury Lynx test bed vehicle as part of a Department of Energy propulsion system development program. An integral part of the inverter is a 4-kw battery charger which utilizes one of the bridge transistors. The overall inverter strategy for this configuration is discussed. The function of the microprocessor-based controller is described. Typical test results of the total vehicle and each of its major components are given, including system efficiencies and test track performance results.

  1. A phased array tracking antenna for vehicles

    NASA Technical Reports Server (NTRS)

    Ohmori, Shingo; Mano, Kazukiko; Tanaka, Kenji; Matsunaga, Makoto; Tsuchiya, Makio

    1990-01-01

    An antenna system including antenna elements and a satellite tracking method is considered a key technology in implementing land mobile satellite communications. In the early stage of land mobile satellite communications, a mechanical tracking antenna system is considered the best candidate for vehicles, however, a phased array antenna will replace it in the near future, because it has many attractive advantages such as a low and compact profile, high speed tracking, and potential low cost. Communications Research Laboratory is now developing a new phased array antenna system for land vehicles based on research experiences of the airborne phased array antenna, which was developed and evaluated in satellite communication experiments using the ETS-V satellite. The basic characteristics of the phased array antenna for land vehicles are described.

  2. Remote monitoring of emissions using on-vehicle sensing and vehicle to roadside communications

    SciTech Connect

    Davis, D.T.

    1995-06-01

    Recent developments in on-vehicle electronics makes practical remote monitoring of vehicle emissions compliance with CARB and EPA regulations. A system consisting of emission controls malfunction sensors, an on-board computer (OBC), and vehicle-to-roadside communications (VRC) would enable enforcement officials to remotely and automatically detect vehicle out-of-compliance status. Remote sensing could be accomplished at highway speeds as vehicles pass a roadside RF antenna and reader unit which would interrogate the on- vehicle monitoring and recording system. This paper will focus on the hardware system components require to achieve this goal with special attention to the VRC; a key element for remote monitoring. this remote sensing concept piggybacks on the development of inexpensive VRC equipment for automatic vehicle identification for electronic toll collection and intelligent transportation applications. Employing an RF transponder with appropriate interface to the OBC and malfunction sensors, a practical monitoring system can be developed with potentially important impact on air quality and enforcement. With such a system in place, the current -- and costly and ineffective -- emission control strategy of periodic smog checking could be replaced or modified.

  3. Unique research challenges for high-speed civil transports

    NASA Technical Reports Server (NTRS)

    Jackson, Charlie M., Jr.; Morris, E. K., Jr.

    1988-01-01

    Market growth and technological advances are expected to lead to a generation of long-range transports that cruise at supersonic or even hypersonic speeds. Current NASA/industry studies will define the market windows in terms of time frame, Mach number, and technology requirements for these aircraft. Initial results indicate that, for the years 2000 to 2020, economically attractive vehicles could have a cruise speed up to Mach 6. The resulting research challenges are unique. They must be met with technologies that will produce commercially successful and environmentally compatible vehicles where none have existed. Several important areas of research were identified for the high-speed civil transports. Among these are sonic boom, takeoff noise, thermal management, lightweight structures with long life, unique propulsion concepts, unconventional fuels, and supersonic laminar flow.

  4. Unique research challenges for high-speed civil transports

    NASA Technical Reports Server (NTRS)

    Jackson, Charlie M., Jr.; Morris, Charles E. K., Jr.

    1987-01-01

    Market growth and technological advances are expected to lead to a generation of long-range transports that cruise at supersonic or even hypersonic speeds. Current NASA/industry studies will define the market windows in terms of time frame, Mach number, and technology requirements for these aircraft. Initial results indicate that, for the years 2000 to 2020, economically attractive vehicles could have a cruise speed up to Mach 6. The resulting research challenges are unique. They must be met with technologies that will produce commercially successful and environmentally compatible vehicles where none have existed. Several important areas of research were identified for the high-speed civil transports. Among these are sonic boom, takeoff noise, thermal management, lightweight structures with long life, unique propulsion concepts, unconventional fuels, and supersonic laminar flow.

  5. Dynamic Analysis of Heavy Vehicle Medium Duty Drive Shaft Using Conventional and Composite Material

    NASA Astrophysics Data System (ADS)

    Kumar, Ashwani; Jain, Rajat; Patil, Pravin P.

    2016-09-01

    The main highlight of this study is structural and modal analysis of single piece drive shaft for selection of material. Drive shaft is used for torque carrying from vehicle transmission to rear wheel differential system. Heavy vehicle medium duty transmission drive shaft was selected as research object. Conventional materials (Steel SM45 C, Stainless Steel) and composite materials (HS carbon epoxy, E Glass Polyester Resin Composite) were selected for the analysis. Single piece composite material drive shaft has advantage over conventional two-piece steel drive shaft. It has higher specific strength, longer life, less weight, high critical speed and higher torque carrying capacity. The main criteria for drive shaft failure are strength and weight. Maximum modal frequency obtained is 919 Hz. Various harmful vibration modes (lateral vibration and torsional vibration) were identified and maximum deflection region was specified. For single-piece drive shaft the natural bending frequency should be higher because it is subjected to torsion and shear stress. Single piece drive shaft was modelled using Solid Edge and Pro-E. Finite Element Analysis was used for structural and modal analysis with actual running boundary condition like frictional support, torque and moment. FEA simulation results were validated with experimental literature results.

  6. A Special Fiber Optic Sensor for Measuring Wheel Loads of Vehicles on Highways.

    PubMed

    Malla, Ramesh B; Sen, Amlan; Garrick, Norman W

    2008-04-11

    This paper presents results from an investigation on a special optical fiber as a load sensor for application in Weigh-in-Motion (WIM) systems to measure wheel loads of vehicles traveling at normal speed on highways. The fiber used has a unique design with two concentric light guiding regions of different effective optical path lengths, which has the potential to enable direct measurement of magnitudes as well as locations of forces acting at multiple points along a single fiber. The optical characteristic of the fiber for intended sensing purpose was first assessed by a simple fiber bending experiment and by correlating the bend radii with the output light signal intensities. A simple laboratory load transmitting/fiber bending device was then designed and fabricated to appropriately bend the optical fiber under applied loads in order to make the fiber work as load sensor. The device with the optical fiber was tested under a universal loading machine and an actual vehicle wheel in the laboratory. The test results showed a good relationship between the magnitude of the applied load and the output optical signal changes. The results also showed a good correlation between the time delay between the inner and outer core light pulses and the distance of the applied load as measured from the output end of the fiber.

  7. Two-dimensional shear wave speed and crawling wave speed recoveries from in vitro prostate data

    PubMed Central

    Lin, Kui; McLaughlin, Joyce R.; Thomas, Ashley; Parker, Kevin; Castaneda, Benjamin; Rubens, Deborah J.

    2011-01-01

    The crawling wave experiment was developed to capture a shear wave induced moving interference pattern that is created by two harmonic vibration sources oscillating at different but almost the same frequencies. Using the vibration sonoelastography technique, the spectral variance image reveals a moving interference pattern. It has been shown that the speed of the moving interference pattern, i.e., the crawling wave speed, is proportional to the shear wave speed with a nonlinear factor. This factor can generate high-speed artifacts in the crawling wave speed images that do not actually correspond to increased stiffness. In this paper, an inverse algorithm is developed to reconstruct both the crawling wave speed and the shear wave speed using the phases of the crawling wave and the shear wave. The feature for the data is the application to in vitro prostate data, while the features for the algorithm include the following: (1) A directional filter is implemented to obtain a wave moving in only one direction; and (2) an L1 minimization technique with physics inspired constraints is employed to calculate the phase of the crawling wave and to eliminate jump discontinuities from the phase of the shear wave. The algorithm is tested on in vitro prostate data measured at the Rochester Center for Biomedical Ultrasound and University of Rochester. Each aspect of the algorithm is shown to yield image improvement. The results demonstrate that the shear wave speed images can have less artifacts than the crawling wave images. Examples are presented where the shear wave speed recoveries have excellent agreement with histology results on the size, shape, and location of cancerous tissues in the glands. PMID:21786924

  8. Two-dimensional shear wave speed and crawling wave speed recoveries from in vitro prostate data.

    PubMed

    Lin, Kui; McLaughlin, Joyce R; Thomas, Ashley; Parker, Kevin; Castaneda, Benjamin; Rubens, Deborah J

    2011-07-01

    The crawling wave experiment was developed to capture a shear wave induced moving interference pattern that is created by two harmonic vibration sources oscillating at different but almost the same frequencies. Using the vibration sonoelastography technique, the spectral variance image reveals a moving interference pattern. It has been shown that the speed of the moving interference pattern, i.e., the crawling wave speed, is proportional to the shear wave speed with a nonlinear factor. This factor can generate high-speed artifacts in the crawling wave speed images that do not actually correspond to increased stiffness. In this paper, an inverse algorithm is developed to reconstruct both the crawling wave speed and the shear wave speed using the phases of the crawling wave and the shear wave. The feature for the data is the application to in vitro prostate data, while the features for the algorithm include the following: (1) A directional filter is implemented to obtain a wave moving in only one direction; and (2) an L(1) minimization technique with physics inspired constraints is employed to calculate the phase of the crawling wave and to eliminate jump discontinuities from the phase of the shear wave. The algorithm is tested on in vitro prostate data measured at the Rochester Center for Biomedical Ultrasound and University of Rochester. Each aspect of the algorithm is shown to yield image improvement. The results demonstrate that the shear wave speed images can have less artifacts than the crawling wave images. Examples are presented where the shear wave speed recoveries have excellent agreement with histology results on the size, shape, and location of cancerous tissues in the glands.

  9. Corrected Launch Speed for a Projectile Motion Laboratory

    NASA Astrophysics Data System (ADS)

    Sanders, Justin M.; Boleman, Michael W.

    2013-09-01

    At our university, students in introductory physics classes perform a laboratory exercise to measure the range of a projectile fired at an assigned angle. A set of photogates is used to determine the initial velocity of the projectile (the launch velocity). We noticed a systematic deviation between the experimentally measured range and the range calculated using the speed as determined by the photogates. In this paper, we will discuss the origin of this systematic error and derive a simple formula to correct it. In particular, we find that the launch speed given by our instrument is significantly different from the actual launch speed of our projectile.

  10. Vehicle Systems Panel deliberations

    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

    The Vehicle Systems Panel addressed materials and structures technology issues related to launch and space vehicle systems not directly associated with the propulsion or entry systems. The Vehicle Systems Panel was comprised of two subpanels - Expendable Launch Vehicles & Cryotanks (ELVC) and Reusable Vehicles (RV). Tom Bales, LaRC, and Tom Modlin, JSC, chaired the expendable and reusable vehicles subpanels, respectively, and co-chaired the Vehicle Systems Panel. The following four papers are discussed in this section: (1) Net Section components for Weldalite Cryogenic Tanks, by Don Bolstad; (2) Build-up Structures for Cryogenic Tanks and Dry Bay Structural Applications, by Barry Lisagor; (3) Composite Materials Program, by Robert Van Siclen; (4) Shuttle Technology (and M&S Lessons Learned), by Stan Greenberg.

  11. Evaluation of battery models for prediction of electric vehicle range

    NASA Technical Reports Server (NTRS)

    Frank, H. A.; Phillips, A. M.

    1977-01-01

    Three analytical models for predicting electric vehicle battery output and the corresponding electric vehicle range for various driving cycles were evaluated. The models were used to predict output and range, and then compared with experimentally determined values determined by laboratory tests on batteries using discharge cycles identical to those encountered by an actual electric vehicle while on SAE cycles. Results indicate that the modified Hoxie model gave the best predictions with an accuracy of about 97 to 98% in the best cases and 86% in the worst case. A computer program was written to perform the lengthy iterative calculations required. The program and hardware used to automatically discharge the battery are described.

  12. Cash transportation vehicle routing and scheduling under stochastic travel times

    NASA Astrophysics Data System (ADS)

    Yan, Shangyao; Wang, Sin-Siang; Chang, Yu-Hsuan

    2014-03-01

    Stochastic disturbances occurring in real-world operations could have a significant influence on the planned routing and scheduling results of cash transportation vehicles. In this study, a time-space network flow technique is utilized to construct a cash transportation vehicle routing and scheduling model incorporating stochastic travel times. In addition, to help security carriers to formulate more flexible routes and schedules, a concept of the similarity of time and space for vehicle routing and scheduling is incorporated into the model. The test results show that the model could be useful for security carriers in actual practice.

  13. Effect of Vehicle Characteristics on Unpaved Road Dust Emissions

    DTIC Science & Technology

    2005-01-01

    monitoring system is shown in Fig. 1. Each downwind tower was instrumented with four DustTraks (Model 8520, TSI Inc., St. Paul , MN) configured to measure... Pitchford , M., 2003a. Vehicle based road dust emissions measurement (III): effect of speed, traffic volume, location, and season on PM10 road dust emissions...Atmospheric Environment 37, 4583–4593. Etyemezian, V., Kuhns, H., Gillies, J., Green, M., Pitchford , M., Watson, J., 2003b. Vehicle based road dust

  14. Comparison of Global Navigation Satellite System Devices on Speed Tracking in Road (Tran)SPORT Applications.

    PubMed

    Supej, Matej; Cuk, Ivan

    2014-12-08

    Global Navigation Satellite Systems (GNSS) are, in addition to being most widely used vehicle navigation method, becoming popular in sport-related tests. There is a lack of knowledge regarding tracking speed using GNSS, therefore the aims of this study were to examine under dynamic conditions: (1) how accurate technologically different GNSS measure speed and (2) how large is latency in speed measurements in real time applications. Five GNSSs were tested. They were fixed to a car's roof-rack: a  smart phone, a wrist watch, a handheld device, a professional system for testing vehicles and a high-end Real Time Kinematics (RTK) GNSS. The speed data were recorded and analyzed during rapid acceleration and deceleration as well as at steady speed. The study produced four main findings. Higher frequency and high quality GNSS receivers track speed at least at comparable accuracy to a vehicle speedometer. All GNSS systems measured maximum speed and movement at a constant speed well. Acceleration and deceleration have different level of error at different speeds. Low cost GNSS receivers operating at 1 Hz sampling rate had high latency (up to 2.16 s) and are not appropriate for tracking speed in real time, especially during dynamic movements.

  15. Comparison of Global Navigation Satellite System Devices on Speed Tracking in Road (Tran)SPORT Applications

    PubMed Central

    Supej, Matej; Čuk, Ivan

    2014-01-01

    Global Naavigation Satellite Systems (GNSS) are, in addition to being most widely used vehicle navigation method, becoming popular in sport-related tests. There is a lack of knowledge regarding tracking speed using GNSS, therefore the aims of this study were to examine under dynamic conditions: (1) how accurate technologically different GNSS measure speed and (2) how large is latency in speed measurements in real time applications. Five GNSSs were tested. They were fixed to a car's roof-rack: a smart phone, a wrist watch, a handheld device, a professional system for testing vehicles and a high-end Real Time Kinematics (RTK) GNSS. The speed data were recorded and analyzed during rapid acceleration and deceleration as well as at steady speed. The study produced four main findings. Higher frequency and high quality GNSS receivers track speed at least at comparable accuracy to a vehicle speedometer. All GNSS systems measured maximum speed and movement at a constant speed well. Acceleration and deceleration have different level of error at different speeds. Low cost GNSS receivers operating at 1 Hz sampling rate had high latency (up to 2.16 s) and are not appropriate for tracking speed in real time, especially during dynamic movements. PMID:25494349

  16. Measurement of whole-body vibration exposure from speed control humps

    NASA Astrophysics Data System (ADS)

    Khorshid, E.; Alkalby, F.; Kamal, H.

    2007-07-01

    The main objective of speed control humps is to introduce shocks and high vibration levels when a car passes over them if its speed is higher than the allowable limit. Hump geometry is a major factor in altering the level of these shocks and specifying the speed limit. However, there is no study of the relationship between whole body vibration due to passing over a speed control hump and lower back pain or occupational diseases. In this study, an experimental investigation is conducted to evaluate health risks associated with different geometry speed control humps. Vibration levels and shocks are measured by a seat pad accelerometer placed under the driver's seat to evaluate hazard risks on the human body's lower back. The assessment is based on two standard methods of measuring whole body vibration: the British standard BS 6841 and the new ISO/DIS standard 2631-5. These methods are used to assess the effects of vehicle type, passenger location in the vehicle, vehicle speed, and speed control hump geometry. It was found that circular speed control humps currently installed on many public roads should be modified in order to eliminate hazards. Two newly designed speed humps were proved to be less hazardous than circular speed control humps.

  17. Speed Reading: Remember the Tortoise

    ERIC Educational Resources Information Center

    Graf, Richard G.

    1973-01-01

    After speed-reading partisans questioned the criticisms in a Psychology Today article, another psychologist conducted a controlled study of speed readers. As we said before, "Speed Readers Don't Read; They Skim". (Editor)

  18. Everyone Deserves a Speeding Ticket.

    ERIC Educational Resources Information Center

    Burris, Harold

    1993-01-01

    Presents a first day physics activity having students determine the fine for a speeding ticket if the speeds considered include the earth's rotation and revolution speed, and the movement through the galaxy. (MDH)

  19. Traction contact performance evaluation at high speeds

    NASA Technical Reports Server (NTRS)

    Tevaarwerk, J. L.

    1981-01-01

    The results of traction tests performed on two fluids are presented. These tests covered a pressure range of 1.0 to 2.5 GPa, an inlet temperature range of 30 'C to 70 'C, a speed range of 10 to 80 m/sec, aspect ratios of .5 to 5 and spin from 0 to 2.1 percent. The test results are presented in the form of two dimensionless parameters, the initial traction slope and the maximum traction peak. With the use of a suitable rheological fluid model the actual traction curves measured can now be reconstituted from the two fluid parameters. More importantly, the knowledge of these parameters together with the fluid rheological model, allow the prediction of traction under conditions of spin, slip and any combination thereof. Comparison between theoretically predicted traction under these conditions and those measured in actual traction tests shows that this method gives good results.

  20. Propellant Mass Fraction Calculation Methodology for Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Holt, James B.; Monk, Timothy S.

    2009-01-01

    Propellant Mass Fraction (pmf) calculation methods vary throughout the aerospace industry. While typically used as a means of comparison between competing launch vehicle designs, the actual pmf calculation method varies slightly from one entity to another. It is the purpose of this paper to present various methods used to calculate the pmf of a generic launch vehicle. This includes fundamental methods of pmf calculation which consider only the loaded propellant and the inert mass of the vehicle, more involved methods which consider the residuals and any other unusable propellant remaining in the vehicle, and other calculations which exclude large mass quantities such as the installed engine mass. Finally, a historic comparison is made between launch vehicles on the basis of the differing calculation methodologies.

  1. Audibility of train horns in passenger vehicles.

    PubMed

    Dolan, Thomas G; Rainey, Jess E

    2005-01-01

    Studies of accident rates associated with train horn bans indicate that motorists rely on horns to warn them of approaching trains. However, researchers have not yet established the levels of horn sounds necessary for detection at railroad crossings. The purpose of this study was to obtain baseline measures of the auditory component of the motorist's detection task. Horn sounds recorded in three test vehicles were presented to 20 normal-hearing listeners in quiet and in four types of vehicle interior noise: engine idling, ventilation fan off; engine idling, fan on; vehicle moving at 30 miles/hr (mph), fan off; and vehicle moving at 30 mph, fan on. Thresholds of the horn sounds were determined by an adaptive procedure. Mean thresholds were lowest in quiet (1.8-4.4 dBA) and highest for the 30-mph, fan-on condition (49.7-58.4 dBA). Mean horn thresholds for all 12 noise conditions were more than 10 dB below the overall level of the vehicle interior noise. Our data are compared with those of previous studies and their implications are discussed. Actual or potential applications of this research include the establishment of a lower limit of signal-to-noise ratios required for the detection of horn sounds at highway-rail crossings.

  2. Baseline tests of the EPC Hummingbird electric passenger vehicle

    NASA Technical Reports Server (NTRS)

    Slavik, R. J.; Maslowski, E. A.; Sargent, N. B.; Birchenough, A. G.

    1977-01-01

    The rear-mounted internal combustion engine in a four-passenger Volkswagen Thing was replaced with an electric motor made by modifying an aircraft generator and powered by 12 heavy-duty, lead-acid battery modules. Vehicle performance tests were conducted to measure vehicle maximum speed, range at constant speed, range over stop-and-go driving schedules, maximum acceleration, gradeability limit, road energy consumption, road power, indicated energy consumption, braking capability, battery charger efficiency, and battery characteristics. Test results are presented in tables and charts.

  3. X-38 Vehicle #132 in Flight Approaching Landing during First Free Flight

    NASA Technical Reports Server (NTRS)

    1999-01-01

    body designed at 80 percent of the size of a projected emergency crew return vehicle for the International Space Station, although two later versions were planned at 100 percent of the CRV size. The X-38 and the actual CRV are patterned after a lifting-body shape first employed in the Air Force-NASA X-24 lifting-body project in the early to mid-1970s. The current vehicle design is base lined with life support supplies for about nine hours of orbital free flight from the space station. It's landing will be fully automated with backup systems which allow the crew to control orientation in orbit, select a deorbit site, and steer the parafoil, if necessary. The X-38 vehicles (designated V131, V132, and V-131R) are 28.5 feet long, 14.5 feet wide, and weigh approximately 16,000 pounds on average. The vehicles have a nitrogen-gas-operated attitude control system and a bank of batteries for internal power. The actual CRV to be flown in space was expected to be 30 feet long. The X-38 project is a joint effort between the Johnson Space Center, Houston, Texas (JSC), Langley Research Center, Hampton, Virginia (LaRC) and Dryden Flight Research Center, Edwards, California (DFRC) with the program office located at JSC. A contract was awarded to Scaled Composites, Inc., Mojave, California, for construction of the X-38 test airframes. The first vehicle was delivered to the JSC in September 1996. The vehicle was fitted with avionics, computer systems and other hardware at Johnson. A second vehicle was delivered to JSC in December 1996. Flight research with the X-38 at Dryden began with an unpiloted captive-carry flight in which the vehicle remained attached to its future launch vehicle, Dryden's B-52 008. There were four captive flights in 1997 and three in 1998, plus the first drop test on March 12, 1998, using the parachutes and parafoil. Further captive and drop tests occurred in 1999. In March 2000 Vehicle 132 completed its third and final free flight in the highest, fastest, and

  4. X-38 Vehicle #132 in Flight with Deployed Parafoil during First Free Flight

    NASA Technical Reports Server (NTRS)

    1999-01-01

    body designed at 80 percent of the size of a projected emergency crew return vehicle for the International Space Station, although two later versions were planned at 100 percent of the CRV size. The X-38 and the actual CRV are patterned after a lifting-body shape first employed in the Air Force-NASA X-24 lifting-body project in the early to mid-1970s. The current vehicle design is base lined with life support supplies for about nine hours of orbital free flight from the space station. It's landing will be fully automated with backup systems which allow the crew to control orientation in orbit, select a deorbit site, and steer the parafoil, if necessary. The X-38 vehicles (designated V131, V132, and V-131R) are 28.5 feet long, 14.5 feet wide, and weigh approximately 16,000 pounds on average. The vehicles have a nitrogen-gas-operated attitude control system and a bank of batteries for internal power. The actual CRV to be flown in space was expected to be 30 feet long. The X-38 project is a joint effort between the Johnson Space Center, Houston, Texas (JSC), Langley Research Center, Hampton, Virginia (LaRC) and Dryden Flight Research Center, Edwards, California (DFRC) with the program office located at JSC. A contract was awarded to Scaled Composites, Inc., Mojave, California, for construction of the X-38 test airframes. The first vehicle was delivered to the JSC in September 1996. The vehicle was fitted with avionics, computer systems and other hardware at Johnson. A second vehicle was delivered to JSC in December 1996. Flight research with the X-38 at Dryden began with an unpiloted captive-carry flight in which the vehicle remained attached to its future launch vehicle, Dryden's B-52 008. There were four captive flights in 1997 and three in 1998, plus the first drop test on March 12, 1998, using the parachutes and parafoil. Further captive and drop tests occurred in 1999. In March 2000 Vehicle 132 completed its third and final free flight in the highest, fastest, and

  5. Vehicle emission sensing and evaluation using the Smog Dog in Houston

    NASA Astrophysics Data System (ADS)

    Yu, Lei; Burrier, Stanley W.

    1997-02-01

    The advanced remote vehicle emission sensing equipment, Smog Dog, is a cost-effective infrared technology designed to measure the levels of vehicle exhaust. This paper presents and demonstrates a research effort for using the Smog Dog to conduct the on-road vehicle exhaust emission collection in the city of Houston, develop modal sensitive emission models and evaluate the EPA approved MOBILE5A emission factor model. The vehicle emission data collection is designed in a manner that various vehicle's modal events such as the acceleration and deceleration under the on-road driving conditions are considered. The Smog Dog remote mission sensor can not only collect the emission concentrations of hydrocarbon, carbon monoxide and oxide of nitrogen but also simultaneously detect the vehicles' instantaneous speeds and acceleration rates. Thus a vehicle's emission rates, which are converted from the collected emission concentration levels, can be functions of its instantaneous speed and acceleration rate. In addition, the Federal Test Procedure driving cycles are emulated using the emission versus speed profile relationships and the resulted emission rate for a predetermined average driving speed can then be compared with the emission factors produced by MOBILE5A. Since the emission models, that are developed based on the on-road emission data collected using the Smog Dog, naturally reflect the on-road driving conditions and the vehicle fleet combinations, they can potentially be used to evaluate the vehicle exhaust emission implications of various advanced traffic management strategies.

  6. External Validity of Contingent Valuation: Comparing Hypothetical and Actual Payments.

    PubMed

    Ryan, Mandy; Mentzakis, Emmanouil; Jareinpituk, Suthi; Cairns, John

    2016-10-09

    Whilst contingent valuation is increasingly used in economics to value benefits, questions remain concerning its external validity that is do hypothetical responses match actual responses? We present results from the first within sample field test. Whilst Hypothetical No is always an Actual No, Hypothetical Yes exceed Actual Yes responses. A constant rate of response reversals across bids/prices could suggest theoretically consistent option value responses. Certainty calibrations (verbal and numerical response scales) minimise hypothetical-actual discrepancies offering a useful solution. Helping respondents resolve uncertainty may reduce the discrepancy between hypothetical and actual payments and thus lead to more accurate policy recommendations. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Analysis of data from electric and hybrid electric vehicle student competitions

    SciTech Connect

    Wipke, K.B.; Hill, N.; Larsen, R.P.

    1994-01-01

    The US Department of Energy sponsored several student engineering competitions in 1993 that provided useful information on electric and hybrid electric vehicles. The electrical energy usage from these competitions has been recorded with a custom-built digital meter installed in every vehicle and used under controlled conditions. When combined with other factors, such as vehicle mass, speed, distance traveled, battery type, and type of components, this information provides useful insight into the performance characteristics of electrics and hybrids. All the vehicles tested were either electric vehicles or hybrid vehicles in electric-only mode, and had an average energy economy of 7.0 km/kwh. Based on the performance of the ``ground-up`` hybrid electric vehicles in the 1993 Hybrid Electric Vehicle Challenge, data revealed a I km/kwh energy economy benefit for every 133 kg decrease in vehicle mass. By running all the electric vehicles at a competition in Atlanta at several different constant speeds, the effects of rolling resistance and aerodynamic drag were evaluated. On average, these vehicles were 32% more energy efficient at 40 km/h than at 72 km/h. The results of the competition data analysis confirm that these engineering competitions not only provide an educational experience for the students, but also show technology performance and improvements in electric and hybrid vehicles by setting benchmarks and revealing trends.

  8. Nonintrusive shaft speed sensor

    NASA Astrophysics Data System (ADS)

    Barkhoudarian, S.; Wyett, L.

    1985-04-01

    A computerized literature search on nonintrusive/noncontacting speed sensing technologies was performed, resulting in 550 abstracts and 42 articles. Fourteen techniques were identified and theoretically analyzed, resulting in the recommendation of the Microwave, Infrared, and Magnetic technologies for experimental evaluation. Test results with a novel magnetic approach, consisting of a permanent magnet placed on the rotating shaft and a pickup coil placed on the housing, indicated detection of a strong signal from 3.5 inches at the lowest required speed (600 rpm), through a 1.75-inch thick Inconel plate. Test results with microwave and infrared speed sensing approaches indicated transmission of sufficient microwave and infrared energy for detection even through heavily bubble-laden water (15 percent cavitation). Although all three techniques demonstrated feasibility, the magnetic sensor was recommended for preliminary design, which indicated no technical obstacles.

  9. Emissions Associated with Electric Vehicle Charging: Impact of Electricity Generation Mix, Charging Infrastructure Availability, and Vehicle Type

    SciTech Connect

    McLaren, Joyce; Miller, John; O'Shaughnessy, Eric; Wood, Eric; Shapiro, Evan

    2016-04-11

    With the aim of reducing greenhouse gas emissions associated with the transportation sector, policy-makers are supporting a multitude of measures to increase electric vehicle adoption. The actual level of emission reduction associated with the electrification of the transport sector is dependent on the contexts that determine when and where drivers charge electric vehicles. This analysis contributes to our understanding of the degree to which a particular electricity grid profile, vehicle type, and charging patterns impact CO2 emissions from light-duty, plug-in electric vehicles. We present an analysis of emissions resulting from both battery electric and plug-in hybrid electric vehicles for four charging scenarios and five electricity grid profiles. A scenario that allows drivers to charge electric vehicles at the workplace yields the lowest level of emissions for the majority of electricity grid profiles. However, vehicle emissions are shown to be highly dependent on the percentage of fossil fuels in the grid mix, with different vehicle types and charging scenarios resulting in fewer emissions when the carbon intensity of the grid is above a defined level. Restricting charging to off-peak hours results in higher total emissions for all vehicle types, as compared to other charging scenarios.

  10. The ac propulsion system for an electric vehicle, phase 1

    NASA Technical Reports Server (NTRS)

    Geppert, S.

    1981-01-01

    A functional prototype of an electric vehicle ac propulsion system was built consisting of a 18.65 kW rated ac induction traction motor, pulse width modulated (PWM) transistorized inverter, two speed mechanically shifted automatic transmission, and an overall drive/vehicle controller. Design developmental steps, and test results of individual components and the complex system on an instrumented test frame are described. Computer models were developed for the inverter, motor and a representative vehicle. A preliminary reliability model and failure modes effects analysis are given.

  11. Improved LTVMPC design for steering control of autonomous vehicle

    NASA Astrophysics Data System (ADS)

    Velhal, Shridhar; Thomas, Susy

    2017-01-01

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

  12. Use of a thermophotovoltaic generator in a hybrid electric vehicle

    SciTech Connect

    Morrison, O.; Seal, M.; West, E.; Connelly, W.

    1999-03-01

    Viking 29 is the World{close_quote}s first thermophotovoltaic (TPV) powered automobile. The prototype was funded by the Department of Energy and designed and built by students and faculty at the Vehicle Research Institute (VRI) at Western Washington University. Viking 29 is a series hybrid electric vehicle that utilizes TPV generators to charge its battery pack. Acceleration, speed, and handling compare to modern high performance sports cars, while emissions are cleaner than current internal combustion engine vehicles. {copyright} {ital 1999 American Institute of Physics.}

  13. Low-Speed Wind Tunnel Tests of Two Waverider Configuration Models

    NASA Technical Reports Server (NTRS)

    Pegg, Robert J.; Hahne, David E.; Cockrell,Charles E., Jr.

    1995-01-01

    A definitive measurement of the low-speed flight characteristics of waverider-based aircraft is required to augment the overall design database for this important class of vehicles which have great potential for efficient high-speed flight. Two separate waverider-derived vehicles were tested; one in the 14- by 22-Foot Tunnel and the other in the 12-Foot Low Speed Tunnel at Langley Research Center. These tests provided measurements of moments and forces about all three axes, control effectiveness, flow field characteristics and the effects of configuration changes. The results of these tunnel tests are summarized and the subsonic aerodynamic characteristics of the two configurations are shown.

  14. Application of Newtonian physics to predict the speed of a gravity racer

    NASA Astrophysics Data System (ADS)

    Driscoll, H. F.; Bullas, A. M.; King, C. E.; Senior, T.; Haake, S. J.; Hart, J.

    2016-07-01

    Gravity racing can be studied using numerical solutions to the equations of motion derived from Newton’s second law. This allows students to explore the physics of gravity racing and to understand how design and course selection influences vehicle speed. Using Euler’s method, we have developed a spreadsheet application that can be used to predict the speed of a gravity powered vehicle. The application includes the effects of air and rolling resistance. Examples of the use of the application for designing a gravity racer are presented and discussed. Predicted speeds are compared to the results of an official world record attempt.

  15. Multivariable Techniques for High-Speed Research Flight Control Systems

    NASA Technical Reports Server (NTRS)

    Newman, Brett A.

    1999-01-01

    This report describes the activities and findings conducted under contract with NASA Langley Research Center. Subject matter is the investigation of suitable multivariable flight control design methodologies and solutions for large, flexible high-speed vehicles. Specifically, methodologies are to address the inner control loops used for stabilization and augmentation of a highly coupled airframe system possibly involving rigid-body motion, structural vibrations, unsteady aerodynamics, and actuator dynamics. Design and analysis techniques considered in this body of work are both conventional-based and contemporary-based, and the vehicle of interest is the High-Speed Civil Transport (HSCT). Major findings include: (1) control architectures based on aft tail only are not well suited for highly flexible, high-speed vehicles, (2) theoretical underpinnings of the Wykes structural mode control logic is based on several assumptions concerning vehicle dynamic characteristics, and if not satisfied, the control logic can break down leading to mode destabilization, (3) two-loop control architectures that utilize small forward vanes with the aft tail provide highly attractive and feasible solutions to the longitudinal axis control challenges, and (4) closed-loop simulation sizing analyses indicate the baseline vane model utilized in this report is most likely oversized for normal loading conditions.

  16. What`s available in industrial vehicles

    SciTech Connect

    Holzhauer, R.

    1997-01-01

    A large assortment of material handling vehicles are available for transporting and lifting products. Equipment is offered with electric (battery) and internal combustion power, operator walking alongside or riding, and inside or outside applications. Factors such as load capacity, turning radius, aisle width, travel speed, lifting height, controls, and cost also enter the selection equation. The various types of vehicles serving the industrial truck market are broken into seven classes, according to guidelines established by the Industrial Truck Association (ITA). This association deals with issues of common interests to manufacturers of fork lifts, tow tractors, rough terrain vehicles, hand pallet trucks, automated guided vehicles, and their suppliers; develops voluntary engineering practices; and collects and disseminates statistical information relating to the industrial truck marketplace. The seven classes are: Electric Motor Rider Trucks; Electric Motor Narrow Aisle Trucks; Electric Motor Hand Trucks; Internal Combustion Engine Trucks, cushion tired; Internal Combustion Engine Trucks, pneumatic tired; Electric and Internal Combustion Engine Tractors; and Rough Terrain Fork Lift Trucks. The following pages present a descriptive and pictorial overview of the equipment available in the first five vehicle classes. The last two categories are not covered because of their limited industrial use.

  17. Automatic vehicle location system

    NASA Technical Reports Server (NTRS)

    Hansen, G. R., Jr. (Inventor)

    1973-01-01

    An automatic vehicle detection system is disclosed, in which each vehicle whose location is to be detected carries active means which interact with passive elements at each location to be identified. The passive elements comprise a plurality of passive loops arranged in a sequence along the travel direction. Each of the loops is tuned to a chosen frequency so that the sequence of the frequencies defines the location code. As the vehicle traverses the sequence of the loops as it passes over each loop, signals only at the frequency of the loop being passed over are coupled from a vehicle transmitter to a vehicle receiver. The frequencies of the received signals in the receiver produce outputs which together represent a code of the traversed location. The code location is defined by a painted pattern which reflects light to a vehicle carried detector whose output is used to derive the code defined by the pattern.

  18. Vehicle underbody fairing

    DOEpatents

    Ortega, Jason M.; Salari, Kambiz; McCallen, Rose

    2010-11-09

    A vehicle underbody fairing apparatus for reducing aerodynamic drag caused by a vehicle wheel assembly, by reducing the size of a recirculation zone formed under the vehicle body immediately downstream of the vehicle wheel assembly. The fairing body has a tapered aerodynamic surface that extends from a front end to a rear end of the fairing body with a substantially U-shaped cross-section that tapers in both height and width. Fasteners or other mounting devices secure the fairing body to an underside surface of the vehicle body, so that the front end is immediately downstream of the vehicle wheel assembly and a bottom section of the tapered aerodynamic surface rises towards the underside surface as it extends in a downstream direction.

  19. Recycling of electronic control units from end-of-life vehicles in China

    NASA Astrophysics Data System (ADS)

    Wang, Junjun; Chen, Ming

    2011-08-01

    In China, electronic control units (ECUs) from end-of-life vehicles (ELVs) are either discarded carelessly or smashed into pieces along with the vehicles for material recycling. With the rapid growth of vehicle population and ECUs in automobiles in China, this recycling scheme poses a serious pollution threat to the environment and wastes resources. This paper presents a new high value-added reuse scheme of ECUs from ELVs and develops a technology roadmap in accordance with China's actual conditions.

  20. Saturn 5 Launch Vehicle Flight Evaluation Report-AS-512 Apollo 17 Mission

    NASA Technical Reports Server (NTRS)

    1973-01-01

    An evaluation of the launch vehicle and lunar roving vehicle performance for the Apollo 17 flight is presented. The objective of the evaluation is to acquire, reduce, analyze, and report on flight data to the extent required to assure future mission success and vehicle reliability. Actual flight problems are identified, their causes are determined, and recommendations are made for corrective action. Summaries of launch operations and spacecraft performance are included. The significant events for all phases of the flight are analyzed.