WorldWideScience

Sample records for vehicle speed brakes

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

    Science.gov (United States)

    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.

  2. Vehicle brake testing system

    Science.gov (United States)

    Stevens, Samuel S [Harriman, TN; Hodgson, Jeffrey W [Lenoir City, TN

    2002-11-19

    This invention relates to a force measuring system capable of measuring forces associated with vehicle braking and of evaluating braking performance. The disclosure concerns an invention which comprises a first row of linearly aligned plates, a force bearing surface extending beneath and beside the plates, vertically oriented links and horizontally oriented links connecting each plate to a force bearing surface, a force measuring device in each link, a transducer coupled to each force measuring device, and a computing device coupled to receive an output signal from the transducer indicative of measured force in each force measuring device. The present invention may be used for testing vehicle brake systems.

  3. Distributed and self-adaptive vehicle speed estimation in the composite braking case for four-wheel drive hybrid electric car

    Science.gov (United States)

    Zhao, Z.-G.; Zhou, L.-J.; Zhang, J.-T.; Zhu, Q.; Hedrick, J.-K.

    2017-05-01

    Considering the controllability and observability of the braking torques of the hub motor, Integrated Starter Generator (ISG), and hydraulic brake for four-wheel drive (4WD) hybrid electric cars, a distributed and self-adaptive vehicle speed estimation algorithm for different braking situations has been proposed by fully utilising the Electronic Stability Program (ESP) sensor signals and multiple powersource signals. Firstly, the simulation platform of a 4WD hybrid electric car was established, which integrates an electronic-hydraulic composited braking system model and its control strategy, a nonlinear seven degrees-of-freedom vehicle dynamics model, and the Burckhardt tyre model. Secondly, combining the braking torque signals with the ESP signals, self-adaptive unscented Kalman sub-filter and main-filter adaptable to the observation noise were, respectively, designed. Thirdly, the fusion rules for the sub-filters and master filter were proposed herein, and the estimation results were compared with the simulated value of a real vehicle speed. Finally, based on the hardware in-the-loop platform and by picking up the regenerative motor torque signals and wheel cylinder pressure signals, the proposed speed estimation algorithm was tested under the case of moderate braking on the highly adhesive road, and the case of Antilock Braking System (ABS) action on the slippery road, as well as the case of ABS action on the icy road. Test results show that the presented vehicle speed estimation algorithm has not only a high precision but also a strong adaptability in the composite braking case.

  4. The dynamic performance and economic benefit of a blended braking system in a multi-speed battery electric vehicle

    International Nuclear Information System (INIS)

    Ruan, Jiageng; Walker, Paul D.; Watterson, Peter A.; Zhang, Nong

    2016-01-01

    Highlights: • Maximum braking energy recovery potentials of various cycles are reported. • Braking strategies are proposed for performance, comfort and energy recovery. • Braking force distributions and wheel slip ratios of different strategies are demonstrated. • The performance of ‘Eco’ strategy is experimentally validated in HWFET and NEDC. • The economic benefit of energy recovering is summarized, regarding to the fuel and maintenance cost saving. - Abstract: As motor-supplied braking torque is applied to the wheels in an entirely different way to hydraulic friction braking systems and it is usually only connected to one axle complicated effects such as wheel slip and locking, vehicle body bounce and braking distance variation will inevitability impact on the performance and safety of braking. The potential for braking energy recovery in typical driving cycles is presented to show its benefit in this study. A general predictive model is designed to analysis the economic and dynamic performance of blended braking systems, satisfying the relevant regulations/laws and critical limitations. Braking strategies for different purposes are proposed to achieve a balance between braking performance, driving comfort and energy recovery rate. Special measures are taken to avoid any effects of motor failure. All strategies are analyzed in detail for various braking events. Advanced driver assistance systems (ADAS), such as ABS and EBD, are properly integrated to work with the regenerative braking system (RBS) harmoniously. Different switching plans during braking are discussed. The braking energy recovery rates and brake force distribution details for different driving cycles are simulated. Results for two of the cycles in an ‘Eco’ mode are measured on a drive train test rig and found to agree with the simulated results to within approximately 10%. Reliable conclusions can thus be gained on the economic benefit and dynamic braking performance. The

  5. Emergency Brake for Tracked Vehicles

    Science.gov (United States)

    Green, G. L.; Hooper, S. L.

    1986-01-01

    Caliper brake automatically stops tracked vehicle as vehicle nears end of travel. Bar on vehicle, traveling to right, dislodges block between brake pads. Pads then press against bar, slowing vehicle by friction. Emergencybraking system suitable for elevators, amusement rides and machine tools.

  6. Cooperative Control of Regenerative Braking and Antilock Braking for a Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Guodong Yin

    2013-01-01

    Full Text Available A new cooperative braking control strategy (CBCS is proposed for a parallel hybrid electric vehicle (HEV with both a regenerative braking system and an antilock braking system (ABS to achieve improved braking performance and energy regeneration. The braking system of the vehicle is based on a new method of HEV braking torque distribution that makes the antilock braking system work together with the regenerative braking system harmoniously. In the cooperative braking control strategy, a sliding mode controller (SMC for ABS is designed to maintain the wheel slip within an optimal range by adjusting the hydraulic braking torque continuously; to reduce the chattering in SMC, a boundary-layer method with moderate tuning of a saturation function is also investigated; based on the wheel slip ratio, battery state of charge (SOC, and the motor speed, a fuzzy logic control strategy (FLC is applied to adjust the regenerative braking torque dynamically. In order to evaluate the performance of the cooperative braking control strategy, the braking system model of a hybrid electric vehicle is built in MATLAB/SIMULINK. It is found from the simulation that the cooperative braking control strategy suggested in this paper provides satisfactory braking performance, passenger comfort, and high regenerative efficiency.

  7. Thermal analysis and temperature characteristics of a braking resistor for high-speed trains for changes in the braking current

    Science.gov (United States)

    Lee, Dae-Dong; Kang, Hyun-Il; Shim, Jae-Myung

    2015-09-01

    Electric brake systems are used in high-speed trains to brake trains by converting the kinetic energy of a railway vehicle to electric energy. The electric brake system consists of a regenerative braking system and a dynamic braking system. When the electric energy generated during the dynamic braking process is changed to heat through the braking resistor, the braking resistor can overheat; thus, failures can occur to the motor block. In this paper, a braking resistor for a high-speed train was used to perform thermal analyses and tests, and the results were analyzed. The analyzed data were used to estimate the dependence of the brake currents and the temperature rises on speed changes up to 300 km/h, at which a test could not be performed.

  8. Stability Control of Vehicle Emergency Braking with Tire Blowout

    OpenAIRE

    Chen, Qingzhang; Liu, Youhua; Li, Xuezhi

    2014-01-01

    For the stability control and slowing down the vehicle to a safe speed after tire failure, an emergency automatic braking system with independent intellectual property is developed. After the system has received a signal of tire blowout, the automatic braking mode of the vehicle is determined according to the position of the failure tire and the motion state of vehicle, and a control strategy for resisting tire blowout additional yaw torque and deceleration is designed to slow down vehicle to...

  9. 78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2013-02-11

    ... initial speeds, vehicle manufacturers will need to develop unique or complicated braking systems to comply... [Docket No. NHTSA-2013-0011] RIN 2127-AL11 Federal Motor Vehicle Safety Standards; Air Brake Systems... rule that amended the Federal motor vehicle safety standard for air brake systems by requiring...

  10. Cooperative Control of Regenerative Braking and Antilock Braking for a Hybrid Electric Vehicle

    OpenAIRE

    Yin, Guodong; Jin, XianJian

    2013-01-01

    A new cooperative braking control strategy (CBCS) is proposed for a parallel hybrid electric vehicle (HEV) with both a regenerative braking system and an antilock braking system (ABS) to achieve improved braking performance and energy regeneration. The braking system of the vehicle is based on a new method of HEV braking torque distribution that makes the antilock braking system work together with the regenerative braking system harmoniously. In the cooperative braking control strategy, a sli...

  11. An Intelligent Regenerative Braking Strategy for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Zhibin Song

    2011-09-01

    Full Text Available Regenerative braking is an effective approach for electric vehicles (EVs to extend their driving range. A fuzzy-logic-based regenerative braking strategy (RBS integrated with series regenerative braking is developed in this paper to advance the level of energy-savings. From the viewpoint of securing car stability in braking operations, the braking force distribution between the front and rear wheels so as to accord with the ideal distribution curve are considered to prevent vehicles from experiencing wheel lock and slip phenomena during braking. Then, a fuzzy RBS using the driver’s braking force command, vehicle speed, battery SOC, battery temperature are designed to determine the distribution between friction braking force and regenerative braking force to improve the energy recuperation efficiency. The experimental results on an “LF620” prototype EV validated the feasibility and effectiveness of regenerative braking and showed that the proposed fuzzy RBS was endowed with good control performance. The maximum driving range of LF620 EV was improved by 25.7% compared with non-RBS conditions.

  12. Enhanced Regenerative Braking Strategies for Electric Vehicles: Dynamic Performance and Potential Analysis

    OpenAIRE

    Boyi Xiao; Huazhong Lu; Hailin Wang; Jiageng Ruan; Nong Zhang

    2017-01-01

    A regenerative braking system and hydraulic braking system are used in conjunction in the majority of electric vehicles worldwide. We propose a new regenerative braking distribution strategy that is based on multi-input fuzzy control logic while considering the influences of the battery’s state of charge, the brake strength and the motor speed. To verify the braking performance and recovery economy, this strategy was applied to a battery electric vehicle model and compared with two other impr...

  13. Brake blending strategy for a hybrid vehicle

    Science.gov (United States)

    Boberg, Evan S.

    2000-12-05

    A hybrid electric powertrain system is provided including a transmission for driving a pair of wheels of a vehicle and a heat engine and an electric motor/generator coupled to the transmission. A friction brake system is provided for applying a braking torque to said vehicle. A controller unit generates control signals to the electric motor/generator and the friction brake system for controllably braking the vehicle in response to a drivers brake command. The controller unit determines and amount of regenerative torque available and compares this value to a determined amount of brake torque requested for determining the control signals to the electric motor/generator and the friction brake system.

  14. Modeling thermal effects in braking systems of railway vehicles

    Directory of Open Access Journals (Sweden)

    Milošević Miloš S.

    2012-01-01

    Full Text Available The modeling of thermal effects has become increasingly important in product design in different transport means, road vehicles, airplanes, railway vehicles, and so forth. The thermal analysis is a very important stage in the study of braking systems, especially of railway vehicles, where it is necessary to brake huge masses, because the thermal load of a braked railway wheel prevails compared to other types of loads. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of railway wheels. Thus induced thermal loads determine thermomechanical behavior of the structure of railway wheels. In cases of thermal overloads, which mainly occur as a result of long-term braking on down-grade railroads, the generation of stresses and deformations occurs, whose consequences are the appearance of cracks on the rim of a wheel and the final total wheel defect. The importance to precisely determine the temperature distribution caused by the transfer process of the heat generated during braking due to the friction on contact surfaces of the braking system makes it a challenging research task. Therefore, the thermal analysis of a block-braked solid railway wheel of a 444 class locomotive of the national railway operator Serbian Railways is processed in detail in this paper, using analytical and numerical modeling of thermal effects during long-term braking for maintaining a constant speed on a down-grade railroad.

  15. Rotary Speed Sensor for Antilocking Brakes

    Science.gov (United States)

    Berdahl, C. M.

    1986-01-01

    Sensor based on fluidic principles produces negative pressure approximately proportional to rotational speed. Sensor developed as part of antilocking brake system for motorcycles. Uses inlet pressure rather than outlet pressure as braking-control signal, eliminating pressure pulsations caused by pump vanes and ensuring low-noise signal. Sensor is centrifugal air pump turned by one of motorcycle wheels. Air enters pump through orifice plates, and suction taken off through port in pump inlet plenum.

  16. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. [Statutory Provisions] Each locomotive and haulage car used in an... permit automatic brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other...

  17. Combined braking system for hybrid vehicle

    Science.gov (United States)

    Kulekina, A. V.; Bakholdin, P. A.; Shchurov, N. I.

    2017-10-01

    The paper presents an analysis of surface vehicle’s existing braking systems. The technical solution and brake-system design were developed for use of regenerative braking energy. A technical parameters comparison of energy storage devices of various types was made. Based on the comparative analysis, it was decided to use supercapacitor because of its applicability for an electric drive intermittent operation. The calculation methods of retarder key components were proposed. Therefrom, it was made a conclusion that rebuild gasoline-electric vehicles are more efficient than gasoline ones.

  18. Analysis of downshift’s improvement to energy efficiency of an electric vehicle during regenerative braking

    International Nuclear Information System (INIS)

    Li, Liang; Li, Xujian; Wang, Xiangyu; Song, Jian; He, Kai; Li, Chenfeng

    2016-01-01

    Highlights: • Downshift is effective in improving the energy efficiency of electric vehicles. • Energy improvement of downshift varies with vehicle speed and brake strength. • The designed nonlinear sliding mode observer is accurate in estimating bake torque. • The proposed resembling PWM method is practical to regulate hydraulic pressure. • The effect of downshift on braking safety and comfort can be restrained by control. - Abstract: Downshift during regenerative braking helps to improve the energy efficiency of electric vehicles. Two main problems are involved in the downshift process. One is the determination of optimal downshift point, and the other is the cooperative control of regenerative braking and hydraulic braking. In order to achieve a systemic solution to these problems, a hierarchical control strategy is brought forward for an electric vehicle with a two-speed automated mechanical transmission. For the upper controller, an off-line calculation and on-line look-up table method is adopted to obtain the optimal downshift point, and a series regenerative braking distribution strategy is designed. For the medium controller, a nonlinear sliding mode observer is designed to obtain the actual hydraulic brake torque. For the lower controller, cooperative control of regenerative braking and hydraulic braking is given to ensure brake safety during downshift process, and a resembling pulse width modulation method is proposed to regulated the hydraulic brake torque. Simulation results and hardware-in-loop test show that the proposed algorithm is effective in improving the energy efficiency of electric vehicles.

  19. IDEAL BRAKE FORCE DISTRIBUTION BETWEEN THE AXLES OF THE TWO-AXLE VEHICLE SERVICE BRAKE APPLICATIONS

    Directory of Open Access Journals (Sweden)

    M. Podryhalo

    2015-07-01

    Full Text Available The obtained analytical expressions allow us to evaluate the stability of two-axle vehicles at various slowdowns. An analytical expression for calculating the ideal according to condition stability ensuring of a two-axle vehicle at service brake applications of brake force distribution allows to offer automatic control devices for brake force adjucement. With decellerationg growth of the two-axle vehicle at service braking the braking force acting on the front axle should decrease relative to the brake force on the rear axle.

  20. Vehicle State Estimator based regenerative braking implementation on an electric vehicle to improve lateral vehicle stability

    NARCIS (Netherlands)

    Jansen, S.T.H.; van Boekel, J.J.P.; Iersel, van S.S.; Besselink, I.J.M.; Nijmeijer, H.

    2013-01-01

    The driving range of electric vehicles can be extended using regenerative braking. Regenerative braking uses the electric drive system, and therefore only the driven wheels, for decelerating the vehicle. Braking on one axle affects the stability of the vehicle, especially for road conditions with

  1. Vehicle state estimator based regenerative braking implementation on an electric vehicle to improve lateral vehicle stability

    NARCIS (Netherlands)

    Jansen, S.T.H.; Boekel, J.J.P. van; Iersel, S.S. van; Besselink, I.J.M.; Nijmeijer, H.

    2013-01-01

    The driving range of electric vehicles can be extended using regenerative braking. Regenerative braking uses the elctric drive system, and therefore only the driven wheels, for decelerating the vehicle. Braking on one axle affects the stability of the vehicle, especially for road conditions with

  2. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    Science.gov (United States)

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  3. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, Susan R.

    1995-01-01

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

  4. Electric vehicle regenerative antiskid braking and traction control system

    Science.gov (United States)

    Cikanek, S.R.

    1995-09-12

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

  5. Energetic optimization of regenerative braking for high speed railway systems

    International Nuclear Information System (INIS)

    Frilli, Amedeo; Meli, Enrico; Nocciolini, Daniele; Pugi, Luca; Rindi, Andrea

    2016-01-01

    Highlights: • A model of longitudinal dynamics of the High-speed train ETR1000 is presented. • The model includes on board traction and braking subsystems. • Interactions between overhead line and power line are modelled. • The model is validated on real experimental data. • An energy storage strategy for a high-speed line is proposed. - Abstract: The current development trend in the railway field has led to an ever increasing interest for the energetic optimization of railway systems (especially considering the braking phases), with a strong attention to the mutual interactions between the loads represented by railway vehicles and the electrical infrastructure, including all the sub-systems related to distribution and smart energy management such as energy storage systems. In this research work, the authors developed an innovative coupled modelling approach suitable for the analysis of the energetic optimization of railway systems and based on the use of the new object oriented language Matlab-Simscape™, which presents several advantages with respect to conventional modelling tools. The proposed model has been validated considering an Italian Direct Current High-speed line and the High-speed train ETR 1000. Furthermore, the model has been used to perform an efficiency analysis, considering the use of energy storage devices. The results obtained with the developed model show that the use of energy recovery systems in high-speed railway can provide great opportunities of energy savings.

  6. Research of braking process of transport vehicle with hydraulic brake system parameters

    OpenAIRE

    Vladimirov, Oleg

    2005-01-01

    Emergency braking of a vehicle is bound with many factors, such as the behaviour of the driver, the drive of the vehicle braking system, the braking mechanisms, the condition of the tyres, and the properties of the pavement. This process involves all parameters of the system “the driver – the vehicle – the road”. In order to investigate the efficiency of braking process upon specific conditions, it is necessary to examine all physical processes that take place in the vehicle on pressing the b...

  7. Enhanced Regenerative Braking Strategies for Electric Vehicles: Dynamic Performance and Potential Analysis

    Directory of Open Access Journals (Sweden)

    Boyi Xiao

    2017-11-01

    Full Text Available A regenerative braking system and hydraulic braking system are used in conjunction in the majority of electric vehicles worldwide. We propose a new regenerative braking distribution strategy that is based on multi-input fuzzy control logic while considering the influences of the battery’s state of charge, the brake strength and the motor speed. To verify the braking performance and recovery economy, this strategy was applied to a battery electric vehicle model and compared with two other improved regenerative braking strategies. The performance simulation was performed using standard driving cycles (NEDC, LA92, and JP1015 and a real-world-based urban cycle in China. The tested braking strategies satisfied the general safety requirements of Europe (as specified in ECE-13H, and the emergency braking scenario and economic potential were tested. The simulation results demonstrated the differences in the braking force distribution performance of these three regenerative braking strategies, the feasibility of the braking methods for the proposed driving cycles and the energy economic potential of the three strategies.

  8. Diagnostics monitor of the braking efficiency in the on board diagnostics system for the motor vehicles

    Science.gov (United States)

    Gajek, Andrzej

    2016-09-01

    The article presents diagnostics monitor for control of the efficiency of brakes in various road conditions in cars equipped with pressure sensor in brake (ESP) system. Now the brake efficiency of the vehicles is estimated periodically in the stand conditions on the base of brake forces measurement or in the road conditions on the base of the brake deceleration. The presented method allows to complete the stand - periodical tests of the brakes by current on board diagnostics system OBD for brakes. First part of the article presents theoretical dependences between deceleration of the vehicle and brake pressure. The influence of the vehicle mass, initial speed of braking, temperature of brakes, aerodynamic drag, rolling resistance, engine resistance, state of the road surface, angle of the road sloping on the deceleration have been analysed. The manner of the appointed of these parameters has been analysed. The results of the initial investigation have been presented. At the end of the article the strategy of the estimation and signalization of the irregular value of the deceleration are presented.

  9. Influences of braking system faults on the vehicle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Straky, H.; Kochem, M.; Schmitt, J.; Hild, R.; Isermann, R. [Technische Univ., Darmstadt (Germany). Inst. of Automatic Control

    2001-07-01

    From a safety point of view the braking system is, besides the driver, one of the key subsystems in a car. The driver, as an adaptive control system, might not notice small faults in the hydraulic part of the braking system and sooner or later critical braking situations, e.g. due to a brake-circuit failure, may occur. Most of the drivers are not capable to deal with such critical situations. Therefore this paper investigates the influence of faults in the braking system on the dynamic vehicle behavior and the steering inputs of the driver to keep the vehicle on the desired course. (orig.)

  10. Combined emergency braking and turning of articulated heavy vehicles

    OpenAIRE

    Morrison, G; Cebon, David

    2017-01-01

    ‘Slip control’ braking has been shown to reduce the emergency stopping distance of an experimental heavy goods vehicle by up to 19%, compared to conventional electronic/anti-lock braking systems (EBS). However, little regard has been given to the impact of slip control braking on the vehicle’s directional dynamics. This paper uses validated computer models to show that slip control could severely degrade directional performance during emergency braking. A modified slip control strategy, ‘atte...

  11. Dynamics of braking vehicles: from Coulomb friction to anti-lock braking systems

    International Nuclear Information System (INIS)

    Tavares, J M

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and without sliding. The advantage of using an anti-lock braking system (ABS) is put in evidence, and a quantitative estimate of its efficiency is proposed and discussed

  12. Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lascurain, Mary Beth [ORNL; Capps, Gary J [ORNL; Franzese, Oscar [ORNL

    2013-10-01

    The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data

  13. Electric vehicle speed control

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, W.R.; Mc Auliffe, G.N.; Schlageter, G.A.

    1987-06-23

    This patent describes an electric vehicle driven by a DC motor. The vehicle has a field winding, an electric resistance element in circuit with the field winding, a switch in the circuit operative when closed to place. The element in parallel with the field winding weakens the field and increases potential motor speed. Also are relay means for operating the switch, means to determine motor speed, computer means for determining whether the motor speed is increasing or decreasing, and means for operating the relay means to close the switch at a first speed. If the motor speed is increased, it actuates the switch at a second speed lower than the first speed but only if switch has been closed previously and motor speed is decreasing.

  14. REGRESSIVE ANALYSIS OF BRAKING EFFICIENCY OF M1 CATEGORY VEHICLES WITH ANTI-BLOCKING BRAKE SYSTEM

    Directory of Open Access Journals (Sweden)

    О. Sarayev

    2015-07-01

    Full Text Available The problematics of assessing the effectiveness of vehicle braking after road accidentoccurrence is considered. For the first time in relation to the modern models of vehicles equipped with anti-lock brakes there were obtained regression models describing the relationship between the coefficient of traction and a random variable of steady deceleration. This does not contradict the essence of the stochastic physical object, which is the process of vehicle braking, unlike the previously adopted method of formalizing this process, using a deterministic function.

  15. Development of Regenerative Braking Co-operative Control System for Automatic Transmission-based Hybrid Electric Vehicle using Electronic Wedge Brake

    OpenAIRE

    Ko, Jiweon; Ko, Sungyeon; Bak, Yongsun; Jang, Mijeong; Yoo, Byoungsoo; Cheon, Jaeseung; Kim, Hyunsoo

    2013-01-01

    This research proposes a regenerative braking co-operative control system for the automatic transmission (AT)-based hybrid electric vehicle (HEV). The brake system of the subject HEV consists of the regenerative braking and the electronic wedge brake (EWB) friction braking for the front wheel, and the hydraulic friction braking for the rear wheel. A regenerative braking co-operative control algorithm is suggested for the regenerative braking and friction braking, which distributes the braking...

  16. The Friction of Vehicle Brake Tandem Master Cylinder

    International Nuclear Information System (INIS)

    Kao, M J; Chang, H; Tsung, T T; Lin, H M

    2006-01-01

    The behaviour of an elastomeric seal for vehicle brake Tandem master cylinder is measured and analyzed in temperature and brake fluids changed. Working conditions are simulated for different piston rod velocity and cylinder supply pressure, in temperature rising, brakefluid boundary and Nanoaluminum oxide brakefluid oxide brakefluid lubrication. The result shows that Nanoaluminum oxide brakefluid with its ball shape can highly reduce friction coefficient to avoid seal excessive wear and reduce slick slip in brake applications

  17. Development of Anti-lock Braking System (ABS) for Vehicles Braking

    OpenAIRE

    Minh Vu Trieu; Oamen Godwin; Vassiljeva Kristina; Teder Leo

    2016-01-01

    This paper develops a real laboratory of anti-lock braking system (ABS) for vehicle and conducts real experiments to verify the ability of this ABS to prevent the vehicle wheel from being locked while braking. Two controllers of PID and fuzzy logic are tested for analysis and comparison. This ABS laboratory is designed for bachelor and master students to simulate and analyze performances of ABS with different control techniques on various roads and load conditions. Thi...

  18. Steering redundancy for self-driving vehicles using differential braking

    Science.gov (United States)

    Jonasson, M.; Thor, M.

    2018-05-01

    This paper describes how differential braking can be used to turn a vehicle in the context of providing fail-operational control for self-driving vehicles. Two vehicle models are developed with differential input. The models are used to explain the bounds of curvature that differential braking provides and they are then validated with measurements in a test vehicle. Particular focus is paid on wheel suspension effects that significantly influence the obtained curvature. The vehicle behaviour and its limitations due to wheel suspension effects are, owing to the vehicle models, defined and explained. Finally, a model-based controller is developed to control the vehicle curvature during a fault by differential braking. The controller is designed to compensate for wheel angle disturbance that is likely to occur during the control event.

  19. Numerical Investigation of Aerodynamic Braking for a Ground Vehicle

    Science.gov (United States)

    Devanuri, Jaya Krishna

    2018-06-01

    The purpose of this article is to observe the effect of an air brake on the aerodynamics of a ground vehicle and also to study the influence of change in the parameters like the velocity of the vehicle, the angle of inclination, height, and position of the air brake on the aerodynamics of the vehicle body. The test subject used is an Ahmed body which is a generic 3D car body as it retains all the aerodynamic characteristics of a ground vehicle. Numerical investigation has been carried out by RNG k-ɛ turbulence model. Results are presented in terms of streamlines and drag coefficient to understand the influence of pertinent parameters on flow physics. It is found that with the use of an air brake, though the drag coefficient remains more or less constant with velocity, it increases with the increase in height and angle of inclination of the air brake. But the effect of position of air brake on the coefficient of drag is surprising since for certain heights of the air brake the drag coefficient is maximum at the foremost point and as the air brake moves towards the rear it is first observed to decrease and then increase. It is also observed that with the increase in height of the air brake the drag coefficient monotonically decreases as the position of the air brake is moved towards the rear. Taguchi method has been employed with L16 orthogonal array to obtain the optimal configuration for the air brake. For each of the selected parameters, four different levels have been chosen to obtain the maximum drag coefficient value. The study could provide an invaluable database for the optimal design of an airbrake for a ground vehicle.

  20. Suggested Research Method for Testing Selected Tribological Properties of Friction Components in Vehicle Braking Systems

    Directory of Open Access Journals (Sweden)

    Borawski Andrzej

    2016-09-01

    Full Text Available The braking system is one of the most important systems in any vehicle. Its proper functioning may determine the health and life the people inside the vehicle as well as other road users. Therefore, it is important that the parameters which characterise the functioning of brakes changed as little as possible throughout their lifespan. Multiple instances of heating and cooling of the working components of the brake system as well as the environment they work in may impact their tribological properties. This article describes a method of evaluating the coefficient of friction and the wear speed of abrasive wear of friction working components of brakes. The methodology was developed on the basis of Taguchi’s method of process optimization.

  1. 75 FR 15620 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2010-03-30

    ... fully develop improved brake systems and also to ensure vehicle control and stability while braking... [Docket No. NHTSA 2009-0175] RIN 2127-AK62 Federal Motor Vehicle Safety Standards; Air Brake Systems... Federal motor vehicle safety standard for air brake systems by requiring substantial improvements in...

  2. 76 FR 55859 - Federal Motor Vehicle Safety Standards No. 121; Air Brake Systems

    Science.gov (United States)

    2011-09-09

    ... during road tests for the braking system, a vehicle equipped with an interlocking axle system or a front... vehicle braking systems, tire characteristics related to lateral force and longitudinal force generation... stopping distance without activating the ABS system by braking the vehicle so that the brake pressure is...

  3. Development of Anti-lock Braking System (ABS) for Vehicles Braking

    Science.gov (United States)

    Minh, Vu Trieu; Oamen, Godwin; Vassiljeva, Kristina; Teder, Leo

    2016-11-01

    This paper develops a real laboratory of anti-lock braking system (ABS) for vehicle and conducts real experiments to verify the ability of this ABS to prevent the vehicle wheel from being locked while braking. Two controllers of PID and fuzzy logic are tested for analysis and comparison. This ABS laboratory is designed for bachelor and master students to simulate and analyze performances of ABS with different control techniques on various roads and load conditions. This paper provides educational theories and practices on the design of control for system dynamics.

  4. An Experimental Study on Hysteresis Characteristics of a Pneumatic Braking System for a Multi-Axle Heavy Vehicle in Emergency Braking Situations

    Directory of Open Access Journals (Sweden)

    Zhe Wang

    2017-08-01

    Full Text Available This study aims to investigate the hysteresis characteristics of a pneumatic braking system for multi-axle heavy vehicles (MHVs. Hysteresis affects emergency braking performance severely. The fact that MHVs have a large size and complex structure leads to more nonlinear coupling property of the pneumatic braking system compared to normal two-axle vehicles. Thus, theoretical analysis and simulation are not enough when studying hysteresis. In this article, the hysteresis of a pneumatic brake system for an eight-axle vehicle in an emergency braking situation is studied based on a novel test bench. A servo drive device is applied to simulate the driver’s braking intensions normally expressed by opening or moving speed of the brake pedal. With a reasonable arrangement of sensors and the NI LabVIEW platform, both the delay time of eight loops and the response time of each subassembly in a single loop are detected in real time. The outcomes of the experiment show that the delay time of each loop gets longer with the increase of pedal opening, and a quadratic relationship exists between them. Based on this, the pressure transient in the system is fitted to a first-order plus time delay model. Besides, the response time of treadle valve and controlling pipeline accounts for more than 80% of the loop’s total delay time, indicating that these two subassemblies are the main contributors to the hysteresis effect.

  5. 75 FR 51521 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness...

    Science.gov (United States)

    2010-08-20

    ....121) mandates antilock braking systems (ABS) on all new air-braked vehicles with a GVWR of 10,000...-0116] Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness of Antilock Braking Systems in Heavy Truck Tractors and Trailers AGENCY: National Highway Traffic...

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

    Science.gov (United States)

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

    2015-01-01

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

  7. Regenerative Braking Compensatory Control Strategy Considering CVT Power Loss for Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2018-02-01

    Full Text Available Hybrid electric vehicles (HEV equipped with continuously variable transmission (CVT adjust the motor operating point continuously to achieve the optimal motor operating efficiency during regenerative braking. Traditional control strategies consider the CVT efficiency as constant, while the CVT efficiency varies in different operating conditions. In order to reflect the transmission efficiency more accurately during regenerative braking, the CVT theoretical torque loss model is firstly established which then leads to the battery–front motor–CVT joint operating efficiency model. The joint operating efficiency model indicates that the system efficiency is influenced by input speed, input torque, CVT speed ratio, and battery SOC (state of charge. The compensatory strategy for the front motor barking force is proposed to make full use of its braking power and the CVT speed ratio control strategy is modified to maintain the optimal operating efficiency of the system. The simulations are performed under three typical braking conditions and UDDS, NYCC, US06 respectively, the results show that the modified control strategy increases the front motor braking power and improves the system operating efficiency.

  8. A mechanical brake hardware-in-the-loop simulation of a railway vehicle that accounts for hysteresis and pneumatic cylinder dynamics

    Directory of Open Access Journals (Sweden)

    Dong-Chan Lee

    2015-11-01

    Full Text Available A brake hardware-in-the-loop simulation system for a railway vehicle provides an effective platform for testing the braking performance under various dangerous braking conditions. However, in general, four-brake calipers are required to implement a mechanical brake system for one car. In this article, we implement a brake hardware-in-the-loop simulation system only with one brake caliper and three air tanks accounting for hysteresis and pneumatic cylinder dynamics, ultimately saving installation space and reducing financial budget costs. Since the brake caliper has a high nonlinearity, such as hysteresis resulting from friction and from the precompressed spring of the brake cylinder, we measured the hysteresis of the brake caliper clamping force for a mechanical brake system using loadcells, based on which a mathematical model was constructed for the hysteresis of the clamping force between the brake pad and the disk. Moreover, the pneumatic cylinder dynamics are identified and are implemented in three air tanks, together with hysteresis nonlinearity. The proposed brake hardware-in-the-loop simulation system is applied to the wheel-slide protection simulation of a railway vehicle with an initial speed of 80 km/h and demonstrated experimentally accounting for the hysteresis and brake cylinder dynamics.

  9. Research on Modeling and Control of Regenerative Braking for Brushless DC Machines Driven Electric Vehicles

    OpenAIRE

    Jian-ping Wen; Chuan-wei Zhang

    2015-01-01

    In order to improve energy utilization rate of battery-powered electric vehicle (EV) using brushless DC machine (BLDCM), the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO) to observe actual braking current and the unknown disturbances of regenerative braking system, ...

  10. Research on Braking Stability of Electro-mechanical Hybrid Braking System in Electric Vehicles

    OpenAIRE

    Ji, Fenzhu; Tian, Mi

    2010-01-01

    For the electro-mechanical hybrid braking system, which is composed of electric brake and general friction brake, the models of electric braking force, total braking force and the utilization adhesion coefficient for front and rear axles were established based on the analysis of braking torque distribution. The variation relationship between electric braking force and friction braking force in different braking intensity was calculated and analyzed with the paralleled-hybridized braking contr...

  11. Torque Coordination Control during Braking Mode Switch for a Plug-in Hybrid Electric Vehicle

    OpenAIRE

    Yang Yang; Chao Wang; Quanrang Zhang; Xiaolong He

    2017-01-01

    Hybrid vehicles usually have several braking systems, and braking mode switches are significant events during braking. It is difficult to coordinate torque fluctuations caused by mode switches because the dynamic characteristics of braking systems are different. In this study, a new type of plug-in hybrid vehicle is taken as the research object, and braking mode switches are divided into two types. The control strategy of type one is achieved by controlling the change rates of clutch hold-dow...

  12. Wheel slide protection control using a command map and Smith predictor for the pneumatic brake system of a railway vehicle

    Science.gov (United States)

    Lee, Nam-Jin; Kang, Chul-Goo

    2016-10-01

    In railway vehicles, excessive sliding or wheel locking can occur while braking because of a temporarily degraded adhesion between the wheel and the rail caused by the contaminated or wet surface of the rail. It can damage the wheel tread and affect the performance of the brake system and the safety of the railway vehicle. To safeguard the wheelset from these phenomena, almost all railway vehicles are equipped with wheel slide protection (WSP) systems. In this study, a new WSP algorithm is proposed. The features of the proposed algorithm are the use of the target sliding speed, the determination of a command for WSP valves using command maps, and compensation for the time delay in pneumatic brake systems using the Smith predictor. The proposed WSP algorithm was verified using experiments with a hardware-in-the-loop simulation system including the hardware of the pneumatic brake system.

  13. Modeling and design of cooperative braking in electric and hybrid vehicles using induction machine and hydraulic brake

    Directory of Open Access Journals (Sweden)

    Zaini Dalimus

    2016-07-01

    Full Text Available In mixed-mode braking applications, the electric motor / generator (M/G and hydraulic pressure valve are controlled to meet the driver’s braking demand. Controlling these braking elements is achieved by modulating the current generated by the M/G and adjusting the fluid pressure to the wheel brake cylinders. This paper aims to model and design combined regenerative and hydraulic braking systems which, comprise an induction electric machine, inverter, NiMH battery, controller, a pressure source, pressure control unit, and brake calipers. A 15 kW 1500 rpm induction machine equipped with a reduction gear having a gear ratio of 4 is used. A hydraulic brake capable to produce fluid pressure up to 40 bar is used. Direct torque control and pressure control are chosen as the control criteria in the M/G and the hydraulic solenoid valve. The braking demands for the system are derived from the Federal Testing Procedure (FTP drive cycle. Two simulation models have been developed in Matlab®/Simulink® to analyze the performance of the control strategy in each braking system. The developed model is validated through experiment. It is concluded that the control system does introduce torque ripple and pressure oscillation in the braking system, but these effects do not affect vehicle braking performance due to the high frequency nature of pressure fluctuation and the damping effect of the vehicle inertia. Moreover, experiment results prove the effectiveness of the developed model.

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

    Science.gov (United States)

    Cikanek, Susan R.

    1994-01-01

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

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

    Science.gov (United States)

    Cikanek, S.R.

    1994-10-25

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

  16. Evaluation strategy of regenerative braking energy for supercapacitor vehicle.

    Science.gov (United States)

    Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

    2015-03-01

    In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  18. Design, Modeling And Control Of Steering And Braking For An Urban Electric Vehicle

    OpenAIRE

    Maciua, Dragos

    1996-01-01

    This report describes research which involved the design modification, modeling and control of automatic steering and braking systems for an urban electric vehicle. The vehicle is equipped with four-wheel independent drive, four-wheel independent braking and four-wheel steering. Control algorithms were developed for steering and braking. Simulation results show the feasibility of the algorithms.

  19. Torque Coordination Control during Braking Mode Switch for a Plug-in Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2017-10-01

    Full Text Available Hybrid vehicles usually have several braking systems, and braking mode switches are significant events during braking. It is difficult to coordinate torque fluctuations caused by mode switches because the dynamic characteristics of braking systems are different. In this study, a new type of plug-in hybrid vehicle is taken as the research object, and braking mode switches are divided into two types. The control strategy of type one is achieved by controlling the change rates of clutch hold-down and motor braking forces. The control strategy of type two is achieved by simultaneously changing the target braking torque during different mode switch stages and controlling the motor to participate in active coordination control. Finally, the torque coordination control strategy is modeled in MATLAB/Simulink, and the results show that the proposed control strategy has a good effect in reducing the braking torque fluctuation and vehicle shocks during braking mode switches.

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

    OpenAIRE

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

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking s...

  1. Comparison between two braking control methods integrating energy recovery for a two-wheel front driven electric vehicle

    International Nuclear Information System (INIS)

    Itani, Khaled; De Bernardinis, Alexandre; Khatir, Zoubir; Jammal, Ahmad

    2016-01-01

    Highlights: • Comparison between two braking methods for an EV maximizing the energy recovery. • Wheels slip ratio control based on robust sliding mode and ECE R13 control methods. • Regenerative braking control strategy. • Energy recovery of a HESS with respect to road surface type and road condition. - Abstract: This paper presents the comparison between two braking methods for a two-wheel front driven Electric Vehicle maximizing the energy recovery on the Hybrid Energy Storage System. The first method consists in controlling the wheels slip ratio while braking using a robust sliding mode controller. The second method will be based on ECE R13H constraints for an M1 passenger vehicle. The vehicle model used for simulation is a simplified five degrees of freedom model. It is driven by two 30 kW permanent magnet synchronous motor (PMSM) recovering energy during braking phases. Several simulation results for extreme braking conditions will be performed and compared on various road type surfaces using Matlab/Simulink®. For an initial speed of 80 km/h, simulation results demonstrate that the difference of energy recovery efficiency between the two control braking methods is beneficial to the ECE constraints control method and it can vary from 3.7% for high friction road type to 11.2% for medium friction road type. At low friction road type, the difference attains 6.6% due to different reasons treated in the paper. The stability deceleration is also discussed and detailed.

  2. Research on motor braking-based DYC strategy for distributed electric vehicle

    Science.gov (United States)

    Zhang, Jingming; Liao, Weijie; Chen, Lei; Cui, Shumei

    2017-08-01

    In order to bring into full play the advantages of motor braking and enhance the handling stability of distributed electric vehicle, a motor braking-based direct yaw moment control (DYC) strategy was proposed. This strategy could identify whether a vehicle has under-steered or overs-steered, to calculate the direct yaw moment required for vehicle steering correction by taking the corrected yaw velocity deviation and slip-angle deviation as control variables, and exert motor braking moment on the target wheels to perform correction in the manner of differential braking. For validation of the results, a combined simulation platform was set up finally to simulate the motor braking control strategy proposed. As shown by the results, the motor braking-based DYC strategy timely adjusted the motor braking moment and hydraulic braking moment on the target wheels, and corrected the steering deviation and sideslip of the vehicle in unstable state, improving the handling stability.

  3. USING COUPLING WEIGHTS AND RATIONAL DISTRIBUTION OF BRAKE FORCES BETWEEN THE AXLES OF WHEELED VEHICLES

    Directory of Open Access Journals (Sweden)

    M. Kholodov

    2011-01-01

    Full Text Available The dependence of the coefficient of coupling weight-axle vehicles under braking and a ra-tional distribution coefficient of braking force to the front axle on the condition of maximum coupling weight.

  4. Research on Modeling and Control of Regenerative Braking for Brushless DC Machines Driven Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Jian-ping Wen

    2015-01-01

    Full Text Available In order to improve energy utilization rate of battery-powered electric vehicle (EV using brushless DC machine (BLDCM, the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO to observe actual braking current and the unknown disturbances of regenerative braking system, the autodisturbances rejection controller (ADRC for controlling the braking current is developed. Experimental results show that the proposed method gives better recovery efficiency and is robust to disturbances.

  5. Unified Brake Service by a Hierarchical Controller for Active Deceleration Control in an Electric and Automated Vehicle

    Directory of Open Access Journals (Sweden)

    Yuliang Nie

    2017-12-01

    Full Text Available Unified brake service is a universal service for generating certain brake force to meet the demand deceleration and is essential for an automated driving system. However, it is rather difficult to control the pressure in the wheel cylinders to reach the target deceleration of the automated vehicle, which is the key issue of the active deceleration control system (ADC. This paper proposes a hierarchical control method to actively control vehicle deceleration with active-brake actuators. In the upper hierarchical, the target pressure of wheel cylinders is obtained by dynamic equations of a pure electric vehicle. In the lower hierarchical, the solenoid valve instructions and the pump speed of hydraulic control unit (HCU are determined to satisfy the desired pressure with the feedback of measured wheel cylinder pressure by pressure sensors. Results of road experiments of a pure electric and automated vehicle indicate that the proposed method realizes the target deceleration accurately and efficiently.

  6. A method to achieve comparable thermal states of car brakes during braking on the road and on a high-speed roll-stand

    Science.gov (United States)

    Wolff, Andrzej

    2010-01-01

    The temperature of a brake friction surface influences significantly the braking effectiveness. The paper describes a heat transfer process in car brakes. Using a developed program of finite element method, the temperature distributions in brake rotors (disc and drum brake) of a light truck have been calculated. As a preliminary consistency criterion of the brake thermal state in road and roll-stand braking conditions, a balance of the energy cumulated in the brake rotor has been taken into account. As the most reliable consistency criterion an equality of average temperatures of the friction surface has been assumed. The presented method allows to achieve on a roll-stand the analogical thermal states of automotive brakes, which are observed during braking in road conditions. Basing on this method, it is possible to calculate the braking time and force for a high-speed roll-stand. In contrast to the previous papers of the author, new calculation results have been presented.

  7. The dynamics of antilock brake systems

    Science.gov (United States)

    Denny, Mark

    2005-11-01

    The nonlinear dynamics of automobile braking are investigated. Nonlinearity arises because of the manner in which the friction coefficient between vehicle tyres and road surface depends upon vehicle speed and wheel angular speed. We show how antilock brake systems approach optimum braking performance.

  8. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2011-07-27

    ... [Docket No. NHTSA-2009-0175] RIN 2127-AK84 Federal Motor Vehicle Safety Standards; Air Brake Systems... final rule that amended the Federal motor vehicle safety standard for air brake systems by requiring... between Bendix Commercial Vehicle Systems and Dana Corporation; and ArvinMeritor. The agency received four...

  9. Evaluation of the crash mitigation effect of low-speed automated emergency braking systems based on insurance claims data.

    Science.gov (United States)

    Isaksson-Hellman, Irene; Lindman, Magdalena

    2016-09-01

    The aim of the present study was to evaluate the crash mitigation performance of low-speed automated emergency braking collision avoidance technologies by examining crash rates, car damage, and personal injuries. Insurance claims data were used to identify rear-end frontal collisions, the specific situations where the low-speed automated emergency braking system intervenes. We compared cars of the same model (Volvo V70) with and without the low-speed automated emergency braking system (AEB and no AEB, respectively). Distributions of spare parts required for car repair were analyzed to identify car damage, and crash severity was estimated by comparing the results with laboratory crash tests. Repair costs and occupant injuries were investigated for both the striking and the struck vehicle. Rear-end frontal collisions were reduced by 27% for cars with low-speed AEB compared to cars without the system. Those of low severity were reduced by 37%, though more severe crashes were not reduced. Accordingly, the number of injured occupants in vehicles struck by low-speed AEB cars was reduced in low-severity crashes. In offset crash configurations, the system was found to be less effective. This study adds important information about the safety performance of collision avoidance technologies, beyond the number of crashes avoided. By combining insurance claims data and information from spare parts used, the study demonstrates a mitigating effect of low-speed AEB in real-world traffic.

  10. Intelligent Braking System using the IR Sensor

    OpenAIRE

    Gajanan Koli

    2017-01-01

    Most of the accidents in four wheeled vehicles occur because of failure of braking systems. Manual method of applying brakes is always dangerous as it leads to accidents. Unconsciousness of driver, failure in the linkages of braking systems, road conditions, uncontrollable speed of the vehicle and manual operation of braking systems are the reasons of accidents. It is necessary to control brakes automatically through electronics devices to minimize the accident problems. In this research pape...

  11. Mechanism analysis and evaluation methodology of regenerative braking contribution to energy efficiency improvement of electrified vehicles

    International Nuclear Information System (INIS)

    Lv, Chen; Zhang, Junzhi; Li, Yutong; Yuan, Ye

    2015-01-01

    Highlights: • The energy flow of an electric vehicle with regenerative brake is analyzed. • Methodology for measuring the regen brake contribution is discussed. • Evaluation parameters of regen brake contribution are proposed. • Vehicle tests are carried out on chassis dynamometer. • Test results verify the evaluation method and parameters proposed. - Abstract: This article discusses the mechanism and evaluation methods of contribution brought by regenerative braking to electric vehicle’s energy efficiency improvement. The energy flow of an electric vehicle considering the braking energy regeneration was analyzed. Then, methodologies for measuring the contribution made by regenerative brake to vehicle energy efficiency improvement were introduced. Based on the energy flow analyzed, two different evaluation parameters were proposed. Vehicle tests were carried out on chassis dynamometer under typical driving cycles with three different control strategies. The experimental results the difference between the proposed two evaluation parameters, and demonstrated the feasibility and effectiveness of the evaluation methodologies proposed

  12. Estimation of Road Friction Coefficient in Different Road Conditions Based on Vehicle Braking Dynamics

    Science.gov (United States)

    Zhao, You-Qun; Li, Hai-Qing; Lin, Fen; Wang, Jian; Ji, Xue-Wu

    2017-07-01

    The accurate estimation of road friction coefficient in the active safety control system has become increasingly prominent. Most previous studies on road friction estimation have only used vehicle longitudinal or lateral dynamics and often ignored the load transfer, which tends to cause inaccurate of the actual road friction coefficient. A novel method considering load transfer of front and rear axles is proposed to estimate road friction coefficient based on braking dynamic model of two-wheeled vehicle. Sliding mode control technique is used to build the ideal braking torque controller, which control target is to control the actual wheel slip ratio of front and rear wheels tracking the ideal wheel slip ratio. In order to eliminate the chattering problem of the sliding mode controller, integral switching surface is used to design the sliding mode surface. A second order linear extended state observer is designed to observe road friction coefficient based on wheel speed and braking torque of front and rear wheels. The proposed road friction coefficient estimation schemes are evaluated by simulation in ADAMS/Car. The results show that the estimated values can well agree with the actual values in different road conditions. The observer can estimate road friction coefficient exactly in real-time and resist external disturbance. The proposed research provides a novel method to estimate road friction coefficient with strong robustness and more accurate.

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

    Directory of Open Access Journals (Sweden)

    Jiankun Peng

    2015-01-01

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

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

    Science.gov (United States)

    Peng, Jiankun; He, Hongwen; Guo, Hongqiang

    2015-01-01

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

  15. Development of a Cooperative Braking System for Front-Wheel Drive Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Di Zhao

    2018-02-01

    Full Text Available Most electric vehicles adopt cooperative braking systems that can blend friction braking torque with regenerative braking torque to achieve higher energy efficiency while maintaining a certain braking performance and driving safety. This paper presented a new cooperative regenerative braking system that contained a fully-decoupled hydraulic braking mechanism based on a modified electric stability control system. The pressure control algorithm and brake force distribution strategy were also discussed. Dynamic models of a front wheel drive electric car equipped with this system and a simulation platform with a driver model and driving cycles were established. Tests to evaluate the braking performance and energy regeneration were simulated and analyzed on this platform and the simulation results showed the feasibility and effectiveness of this system.

  16. Solid state circuit controls direction, speed, and braking of dc motor

    Science.gov (United States)

    Hanna, M. F.

    1966-01-01

    Full-wave bridge rectifier circuit controls the direction, speed, and braking of a dc motor. Gating in the circuit of Silicon Controlled Rectifiers /SCRS/ controls output polarity and braking is provided by an SCR that is gated to short circuit the reverse voltage generated by reversal of motor rotation.

  17. Study on Two-segment Electric-mechanical Composite Braking Strategy of Tracked Vehicle Hybrid Transmission System

    OpenAIRE

    Ma, Tian; Gai, Jiangtao; Ma, Xiaofeng

    2010-01-01

    In order to lighten abrasion of braking system of hybrid electric tracked vehicle, according to characteristic of hybrid electric transmission, electric-mechanical composite braking method was proposed. By means of analyzing performance of electric braking and mechanical braking and three-segment composite braking strategy, two-segment electric-mechanical composite braking strategy was put forward in this paper. Simulation results of Matlab/Simulink indicated that the two-segment electric-mec...

  18. Performance Evaluation of an Anti-Lock Braking System for Electric Vehicles with a Fuzzy Sliding Mode Controller

    OpenAIRE

    Jingang Guo; Xiaoping Jian; Guangyu Lin

    2014-01-01

    Traditional friction braking torque and motor braking torque can be used in braking for electric vehicles (EVs). A sliding mode controller (SMC) based on the exponential reaching law for the anti-lock braking system (ABS) is developed to maintain the optimal slip value. Parameter optimizing is applied to the reaching law by fuzzy logic control (FLC). A regenerative braking algorithm, in which the motor torque is taken full advantage of, is adopted to distribute the braking force between the m...

  19. Improving the performance of a hybrid electric vehicle by utilization regenerative braking energy of vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Mourad, Mohamed [Automotive and Tractors Department, Faculty of Engineering, Minia University (Egypt)

    2011-07-01

    Environmentally friendly vehicles with range and performance capabilities surpassing those of conventional ones require a careful balance among competing goals for fuel efficiency, performance and emissions. It can be recuperated the energy of deceleration case of the vehicle to reuse it to recharge the storage energy of hybrid electric vehicle and increase the state of charge of batteries under the new conditions of vehicle operating in braking phase. Hybrid electric vehicle has energy storage which allows decreasing required peak value of power from prime mover, which is the internal combustion engine. The paper investigates the relationships between the driving cycle phases and the recuperation energy to the batteries system of hybrid electric vehicle. This work describes also a methodology for integrating this type of hybrid electric vehicle in a simulation program. A design optimization framework is then used to find the best position that we can utilize the recuperation energy to recharge the storage batteries of hybrid electric vehicle.

  20. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Science.gov (United States)

    2010-10-01

    ... service brake system, such as a pump, that automatically supplies energy in the event of a primary brake...). S6.1.2. Wind speed. The wind speed is not greater than 5 m/s (11.2 mph). S6.2. Road test surface. S6...

  1. A Study on Control Strategy of Regenerative Braking in the Hydraulic Hybrid Vehicle Based on ECE Regulations

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2013-01-01

    Full Text Available This paper establishes a mathematic model of composite braking in the hydraulic hybrid vehicle and analyzes the constraint condition of parallel regenerative braking control algorithm. Based on regenerative braking system character and ECE (Economic Commission of Europe regulations, it introduces the control strategy of regenerative braking in parallel hydraulic hybrid vehicle (PHHV. Finally, the paper establishes the backward simulation model of the hydraulic hybrid vehicle in Matlab/simulink and makes a simulation analysis of the control strategy of regenerative braking. The results show that this strategy can equip the hydraulic hybrid vehicle with strong brake energy recovery power in typical urban drive state.

  2. Wheel slip dump valve for railway braking system

    Science.gov (United States)

    Zhang, Xuan; Zhang, LiHao; Li, QingXuan; Shi, YanTao

    2017-09-01

    As we all know, pneumatic braking system plays an important role in the safety of the whole vehicle. In the anti slip braking system, the pressure of braking cylinder can be adjusted by the quick power response of wheel slip dump valve, so that the lock situation won’t occur during vehicle service. During the braking of railway vehicles, the braking force provided by braking disc reduces vehicle’s speed. But the locking slip will happen due to the oversize of braking force or the reduction of sticking coefficient between wheel and rail. It will cause not only the decline of braking performance but also the increase of braking distance. In the meanwhile, it will scratch the wheel and influence the stable running of vehicles. Now, the speed of passenger vehicle has been increased. In order to shorten the braking distance as far as possible, sticking stickiness must be fully applied. So the occurrence probability of wheel slip is increased.

  3. Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

    OpenAIRE

    Cai, Wenchuan; Liao, Wenhao; Li, Danyong; Song, Yongduan

    2014-01-01

    Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST) is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate t...

  4. An integrated control strategy for the composite braking system of an electric vehicle with independently driven axles

    Science.gov (United States)

    Sun, Fengchun; Liu, Wei; He, Hongwen; Guo, Hongqiang

    2016-08-01

    For an electric vehicle with independently driven axles, an integrated braking control strategy was proposed to coordinate the regenerative braking and the hydraulic braking. The integrated strategy includes three modes, namely the hybrid composite mode, the parallel composite mode and the pure hydraulic mode. For the hybrid composite mode and the parallel composite mode, the coefficients of distributing the braking force between the hydraulic braking and the two motors' regenerative braking were optimised offline, and the response surfaces related to the driving state parameters were established. Meanwhile, the six-sigma method was applied to deal with the uncertainty problems for reliability. Additionally, the pure hydraulic mode is activated to ensure the braking safety and stability when the predictive failure of the response surfaces occurs. Experimental results under given braking conditions showed that the braking requirements could be well met with high braking stability and energy regeneration rate, and the reliability of the braking strategy was guaranteed on general braking conditions.

  5. A Study on Control Strategy of Regenerative Braking in the Hydraulic Hybrid Vehicle Based on ECE Regulations

    OpenAIRE

    Liu, Tao; Zheng, Jincheng; Su, Yongmao; Zhao, Jinghui

    2013-01-01

    This paper establishes a mathematic model of composite braking in the hydraulic hybrid vehicle and analyzes the constraint condition of parallel regenerative braking control algorithm. Based on regenerative braking system character and ECE (Economic Commission of Europe) regulations, it introduces the control strategy of regenerative braking in parallel hydraulic hybrid vehicle (PHHV). Finally, the paper establishes the backward simulation model of the hydraulic hybrid vehicle in Matlab/simul...

  6. A novel technique for optimal integration of active steering and differential braking with estimation to improve vehicle directional stability.

    Science.gov (United States)

    Mirzaeinejad, Hossein; Mirzaei, Mehdi; Rafatnia, Sadra

    2018-06-11

    This study deals with the enhancement of directional stability of vehicle which turns with high speeds on various road conditions using integrated active steering and differential braking systems. In this respect, the minimum usage of intentional asymmetric braking force to compensate the drawbacks of active steering control with small reduction of vehicle longitudinal speed is desired. To this aim, a new optimal multivariable controller is analytically developed for integrated steering and braking systems based on the prediction of vehicle nonlinear responses. A fuzzy programming extracted from the nonlinear phase plane analysis is also used for managing the two control inputs in various driving conditions. With the proposed fuzzy programming, the weight factors of the control inputs are automatically tuned and softly changed. In order to simulate a real-world control system, some required information about the system states and parameters which cannot be directly measured, are estimated using the Unscented Kalman Filter (UKF). Finally, simulations studies are carried out using a validated vehicle model to show the effectiveness of the proposed integrated control system in the presence of model uncertainties and estimation errors. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Sprag solenoid brake

    Science.gov (United States)

    Dane, P. H.

    1972-01-01

    Operation of solenoid braking mechanism is discussed. Illustrations of construction of the brake are provided. Device is used for braking low or medium speed shaft rotations and produces approximately ten times braking torque of similar solenoid brakes.

  8. A New Model of Stopping Sight Distance of Curve Braking Based on Vehicle Dynamics

    Directory of Open Access Journals (Sweden)

    Rong-xia Xia

    2016-01-01

    Full Text Available Compared with straight-line braking, cornering brake has longer braking distance and poorer stability. Therefore, drivers are more prone to making mistakes. The braking process and the dynamics of vehicles in emergency situations on curves were analyzed. A biaxial four-wheel vehicle was simplified to a single model. Considering the braking process, dynamics, force distribution, and stability, a stopping sight distance of the curve braking calculation model was built. Then a driver-vehicle-road simulation platform was built using multibody dynamic software. The vehicle test of brake-in-turn was realized in this platform. The comparison of experimental and calculated values verified the reliability of the computational model. Eventually, the experimental values and calculated values were compared with the stopping sight distance recommended by the Highway Route Design Specification (JTGD20-2006; the current specification of stopping sight distance does not apply to cornering brake sight distance requirements. In this paper, the general values and limits of the curve stopping sight distance are presented.

  9. Brake wear from vehicles as an important source of diffuse copper pollution

    NARCIS (Netherlands)

    Hulskotte, J.H.J.; Gon, H.A.C.D. van der; Visschedijk, A.J.H.; Schaap, M.

    2007-01-01

    In this article we show that brake wear from road traffic vehicles is an important source of atmospheric (participate) copper concentrations in Europe. Consequently, brake wear also contributes significantly to deposition fluxes of copper to surface waters. We estimated the copper emission due to

  10. Fibre-reinforced ceramics for vehicle brakes; Faserverstaerkte Keramiken fuer Bremsenanwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Krenkel, W. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Stuttgart (Germany). Inst. fuer Bauweisen- und Konstruktionsforschung

    2000-08-01

    Fibre-reinforced ceramics are extremely light, with a high fracture toughness, and have a high potential for applications in motor brakes. It is envisaged that they will last through the whole vehicle life. They can be used in passenger cars, industrial vehicles, high-speed trains, aircraft and in safety brakes in machines, plants and haulage systems. [German] Im Rahmen der Raumfahrt-Forschung wurde vom Deutschen Zentrum fuer Luft- und Raumfahrt (DLR) das Fluessigsilicier-Verfahren zur Herstellung von keramischen Verbundwerkstoffen entwickelt. Diese extrem leichten und bruchzaehen Faserkeramiken haben sich unter den besonderen Bedingungen des Weltraums beispielsweise fuer Hitzeschutzstrukturen von Raumfahrzeugen hervorragend bewaehrt. Darueber hinaus zeigten Untersuchungen ein hohes Anwendungspotenzial fuer neue Bremsen mit deutlich verbesserten Reibungs- und Verschleisseigenschaften. Weiterentwicklungen des keramischen Gefueges fuehrten zu innovativen Leichtbau- bzw. Hochleistungs-Bremsen auf der Basis dieser harten und hitzebestaendigen Verbundwerkstoffe. Bereits mit serienmaessigen Bremsbelaegen wurden die heute geltenden Verschleiss- und Reibwertanforderungen teilweise weit uebertroffen. Die Leistungsfaehigkeit heutiger Bremssysteme kann damit deutlich gesteigert und die ungefederte Masse des Fahrwerks drastisch reduziert werden. Mit der zielgerichteten Anpassung geeigneter Belaege auf die neuen Keramik-Bremsscheiben scheint erstmals ein Einsatz von Lebensdauerbremsen moeglich zu sein, deren geringe Verschleissraten einen Austausch der Bremsscheiben waehrend der Betriebszeit eines Fahrzeugs ueberfluessig machen. Neben der Verwendung dieser innovativen Leichtbaubremsen im PKW-Bereich wird zukuenftig deren Einsatz auch fuer Gefahrguttransporter, Hochgeschwindigkeitszuege, Flugzeuge und fuer Sicherheitsbremsen im Maschinen- und Anlagenbau sowie in der Foerdertechnik erwartet. (orig.)

  11. Systems and methods for vehicle speed management

    Science.gov (United States)

    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.

  12. Space Shuttle Rudder Speed Brake Actuator-A Case Study Probabilistic Fatigue Life and Reliability Analysis

    Science.gov (United States)

    Oswald, Fred B.; Savage, Michael; Zaretsky, Erwin V.

    2015-01-01

    The U.S. Space Shuttle fleet was originally intended to have a life of 100 flights for each vehicle, lasting over a 10-year period, with minimal scheduled maintenance or inspection. The first space shuttle flight was that of the Space Shuttle Columbia (OV-102), launched April 12, 1981. The disaster that destroyed Columbia occurred on its 28th flight, February 1, 2003, nearly 22 years after its first launch. In order to minimize risk of losing another Space Shuttle, a probabilistic life and reliability analysis was conducted for the Space Shuttle rudder/speed brake actuators to determine the number of flights the actuators could sustain. A life and reliability assessment of the actuator gears was performed in two stages: a contact stress fatigue model and a gear tooth bending fatigue model. For the contact stress analysis, the Lundberg-Palmgren bearing life theory was expanded to include gear-surface pitting for the actuator as a system. The mission spectrum of the Space Shuttle rudder/speed brake actuator was combined into equivalent effective hinge moment loads including an actuator input preload for the contact stress fatigue and tooth bending fatigue models. Gear system reliabilities are reported for both models and their combination. Reliability of the actuator bearings was analyzed separately, based on data provided by the actuator manufacturer. As a result of the analysis, the reliability of one half of a single actuator was calculated to be 98.6 percent for 12 flights. Accordingly, each actuator was subsequently limited to 12 flights before removal from service in the Space Shuttle.

  13. A Combined Cooperative Braking Model with a Predictive Control Strategy in an Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Hongqiang Guo

    2013-12-01

    Full Text Available Cooperative braking with regenerative braking and mechanical braking plays an important role in electric vehicles for energy-saving control. Based on the parallel and the series cooperative braking models, a combined model with a predictive control strategy to get a better cooperative braking performance is presented. The balance problem between the maximum regenerative energy recovery efficiency and the optimum braking stability is solved through an off-line process optimization stream with the collaborative optimization algorithm (CO. To carry out the process optimization stream, the optimal Latin hypercube design (Opt LHD is presented to discrete the continuous design space. To solve the poor real-time problem of the optimization, a high-precision predictive model based on the off-line optimization data of the combined model is built, and a predictive control strategy is proposed and verified through simulation. The simulation results demonstrate that the predictive control strategy and the combined model are reasonable and effective.

  14. Research on squeal noise of tread brake system in rail freight vehicle

    Science.gov (United States)

    Zhang, Jun; Li, Yong-hua; Fang, Ji; Zhao, Wen-zhong

    2017-07-01

    Brake squeal is a result of a unstable flutter from brake system, it results to the noise pollution in railway side and excessive wear of wheel tread. A finite element model of brake system for rail freight vehicle is set up, the contact and friction between the brake shoe and wheel tread is considered, the complex modals of brake system are calculated, the possibility of happening chatter and squeal noise are analyzed. The results show that the pressure angle or the brake force direction have a important influence on the unstable chatter and squeal noise, the more greater the pressure angle deviates from the wheel center, the more greater the possibility of happening chatter and squeal noise is, and the possibility of happening chatter and squeal noise is also increased along with the addition of friction factor.

  15. New evidence concerning fatal crashes of passenger vehicles before and after adding antilock braking systems.

    Science.gov (United States)

    Farmer, C M

    2001-05-01

    Fatal crash rates for passenger cars and vans were compared for the last model year before four-wheel antilock brakes were introduced and the first model year for which antilock brakes were standard equipment. A prior study, based on fatal crash experience through 1995, reported that vehicle models with antilock brakes were more likely than identical but 1-year-earlier models to be involved in crashes fatal to their own occupants, but were less likely to be involved in crashes fatal to occupants of other vehicles. Overall, there was no significant effect of antilocks on the likelihood of fatal crashes. Similar analyses, based on fatal crash experience during 1996-98, yielded very different results. During 1996-98, vehicles with antilock brakes were again less likely than earlier models to be involved in crashes fatal to occupants of other vehicles, but they were no longer overinvolved in crashes fatal to their own occupants.

  16. Methods of monitoring the technical condition of the braking system of an autonomous vehicle during operation

    Science.gov (United States)

    Revin, A.; Dygalo, V.; Boyko, G.; Lyaschenko, M.; Dygalo, L.

    2018-02-01

    Possibilities of diagnosing of a technical condition of braking system of the autonomous vehicles with automated modules while in service are considered. The concept of sharing of onboard means and stands for diagnosing is presented.

  17. Brake force estimation for electromechanical vehicle brakes; Bremskraft-Rekonstruktion fuer elektromechanische Fahrzeugbremsen

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, R. [Continental Teves (Germany)

    1999-06-01

    Due to the increasing safety and comfort demands of the customer, the functionality of modern brake systems has grown continuously in the last years. However, implementation of the extended functionality in conventional brake hydraulics makes active electronic intervention necessary and therefore requires a lot of technical effort. In recent years the automotive supplier industry has started to develop brake systems which have electromechanical brake actuators generating the brake forces at the individual wheels. Electromechanically actuated wheel brakes need to be operated in a closed control loop. This paper introduces a new method to reconstruct the needed feedback value brake force from easy to measure signals. (orig.) [Deutsch] Aufgrund des gestiegenen Sicherheits- und Komfortbewusstseins der Fahrzeugkaeufer ist die Funktionsvielfalt moderner Bremssysteme in den letzten Jahren staendig gewachsen. Die Umsetzung der erweiterten Funktionalitaet mittels konventioneller Bremsenhydraulik ist jedoch durch den elektronischen, aktiven Eingriff sehr aufwendig. In den letzten Jahren hat daher die Automobilzulieferindustrie begonnen, Bremssysteme zu entwickeln, bei denen die Bremskraft an den einzelnen Raedern von elektromechanischen Bremsaktuatoren aufgebracht wird. Elektromechanisch betaetigte Radbremsen muessen im geschlossenen Regelkreis betrieben werden. Der vorliegende Beitrag, der im Rahmen einer Forschungskooperation zwischen Continental Teves und dem Institut fuer Automatisierungstechnik der TU Darmstadt entstand stellt ein Verfahren vor, mit dem die dafuer benoetigte Rueckfuehrungsgroesse `Bremskraft` aus einfach messbaren Signalen rekonstruiert werden kann. (orig.)

  18. Real Time Speed Measure while Automobile Braking on Soft Sensing Technique

    International Nuclear Information System (INIS)

    Zhu, W B; Li, D S; Lu, Y

    2006-01-01

    Because the braking performance of automobile has close relationship to traffic safety, it is important to detect that. Focusing on the problem that the real time speed is difficult to obtain in detection process, soft sensing technique is introduced in this paper. According to analyzing the relationship of the dynamics equation of a moving automobile, a module of real time speed of braking is set up. By using imitation method with experiment data to get the pressure function of cylinder and analyzing the relationship between the trigging moment of a wheel and the pressure function of brake cylinder, the real time speed is confirmed in good precision. The maximal measurement error of real time speed is 8.7% and the precision can satisfy engineering request

  19. Real Time Speed Measure while Automobile Braking on Soft Sensing Technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, W B; Li, D S; Lu, Y [China Jiliang University, Hangzhou, Zhejiang province, 310018 (China)

    2006-10-15

    Because the braking performance of automobile has close relationship to traffic safety, it is important to detect that. Focusing on the problem that the real time speed is difficult to obtain in detection process, soft sensing technique is introduced in this paper. According to analyzing the relationship of the dynamics equation of a moving automobile, a module of real time speed of braking is set up. By using imitation method with experiment data to get the pressure function of cylinder and analyzing the relationship between the trigging moment of a wheel and the pressure function of brake cylinder, the real time speed is confirmed in good precision. The maximal measurement error of real time speed is 8.7% and the precision can satisfy engineering request.

  20. Fatal crashes of passenger vehicles before and after adding antilock braking systems.

    Science.gov (United States)

    Farmer, C M; Lund, A K; Trempel, R E; Braver, E R

    1997-11-01

    Fatal crash rates of passenger cars and vans were compared for the last model year before four-wheel antilock brakes were introduced and the first model year for which antilock brakes were standard equipment. Vehicles selected for analysis had no other significant design changes between the model years being compared, and the model years with and without antilocks were no more than two years apart. The overall fatal crash rates were similar for the two model years. However, the vehicles with antilocks were significantly more likely to be involved in crashes fatal to their own occupants, particularly single-vehicle crashes. Conversely, antilock vehicles were less likely to be involved in crashes fatal to occupants of other vehicles or nonoccupants (pedestrians, bicyclists). Overall, antilock brakes appear to have had little effect on fatal crash involvement. Further study is needed to better understand why fatality risk has increased for occupants of antilock vehicles.

  1. Driver braking behavior analysis to improve autonomous emergency braking systems in typical Chinese vehicle-bicycle conflicts.

    Science.gov (United States)

    Duan, Jingliang; Li, Renjie; Hou, Lian; Wang, Wenjun; Li, Guofa; Li, Shengbo Eben; Cheng, Bo; Gao, Hongbo

    2017-11-01

    Bicycling is one of the fundamental modes of transportation especially in developing countries. Because of the lack of effective protection for bicyclists, vehicle-bicycle (V-B) accident has become a primary contributor to traffic fatalities. Although AEB (Autonomous Emergency Braking) systems have been developed to avoid or mitigate collisions, they need to be further adapted in various conflict situations. This paper analyzes the driver's braking behavior in typical V-B conflicts of China to improve the performance of Bicyclist-AEB systems. Naturalistic driving data were collected, from which the top three scenarios of V-B accidents in China were extracted, including SCR (a bicycle crossing the road from right while a car is driving straight), SCL (a bicycle crossing the road from left while a car is driving straight) and SSR (a bicycle swerving in front of the car from right while a car is driving straight). For safety and data reliability, a driving simulator was employed to reconstruct these three scenarios and some 25 licensed drivers were recruited for braking behavior analysis. Results revealed that driver's braking behavior was significantly influenced by V-B conflict types. Pre-decelerating behaviors were found in SCL and SSR conflicts, whereas in SCR the subjects were less vigilant. The brake reaction time and brake severity in lateral V-B conflicts (SCR and SCL) was shorter and higher than that in longitudinal conflicts (SSR). The findings improve their applications in the Bicyclist-AEB and test protocol enactment to enhance the performance of Bicyclist-AEB systems in mixed traffic situations especially for developing countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Tailpipe, resuspended road dust, and brake-wear emission factors from on-road vehicles

    Science.gov (United States)

    Abu-Allaban, Mahmoud; Gillies, John A.; Gertler, Alan W.; Clayton, Russ; Proffitt, David

    Intensive mass and chemical measurements were performed at roadside locations in Reno, Nevada, and Durham/Research Triangle Park), North Carolina to derive tailpipe, resuspended road dust, and brake-wear emission factors from in-use vehicles. Continuous particulate matter (PM) data were utilized to derive total emission factors while integrated PM data were used to attribute the calculated emission factors to different mechanisms using chemical mass balance receptor modeling and scanning electron microscopy techniques. Resuspended road dust and tailpipe emissions were found to be the dominant mechanisms that contribute significantly to the total PM 10 and PM 2.5 emission factors, respectively. Small contributions from brake-wear were observed at locations where strong braking occurs, but no tire-wear was seen at any sampling location. PM 10 emission rates from light-duty spark ignition (LDSI) vehicles ranged from 40 to 780 mg/km, 10 to 70 mg/km, and 0 to 80 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 10 emission rates from heavy-duty vehicles ranged from 230 to 7800 mg/km, 60 to 570 mg/km, and 0 to 610 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 2.5 emission rates from LDSI vehicles ranged from 2 to 25 mg/km, 10 to 50 mg/km, and 0 to 5 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively. PM 2.5 emission rates from heavy-duty vehicles ranged from 15 to 300 mg/km, 60 to 480 mg/km, and 0 to 15 mg/km per vehicle for road dust, tailpipe, and brake-wear, respectively.

  3. Effects of main actor, outcome and affect on biased braking speed judgments

    Directory of Open Access Journals (Sweden)

    Ola Svenson

    2012-05-01

    Full Text Available Subjects who judged speed in a driving scenario overestimated how fast they could decelerate when speeding compared to when keeping within the speed limit (Svenson, 2009. The purpose of the present studies were to replicate studies conducted in Europe with subjects in the U.S., to study the influence of speed unit (kph vs. mph, affective reactions to outcome (collision and identity of main actor (driver on braking speed judgments. The results replicated the European findings and the outcome affective factor (passing a line/killing a child and the actor factor (subject/driver in general had significant effects on judgments of braking speed. The results were related to psychological theory and applied implications were discussed.

  4. Brake Performance Analysis of ABS for Eddy Current and Electrohydraulic Hybrid Brake System

    Directory of Open Access Journals (Sweden)

    Ren He

    2013-01-01

    Full Text Available This paper introduces an eddy current and electro-hydraulic hybrid brake system to solve problems such as wear, thermal failure, and slow response of traditional vehicle brake system. Mathematical model was built to calculate the torque of the eddy current brake system and hydraulic brake system and analyze the braking force distribution between two types of brake systems. A fuzzy controller on personal computer based on LabVIEW and Matlab was designed and a set of hardware in the loop system was constructed to validate and analyze the performance of the hybrid brake system. Through lots of experiments on dry and wet asphalt roads, the hybrid brake system achieves perfect performance on the experimental bench, the hybrid system reduces abrasion and temperature of the brake disk, response speed is enhanced obviously, fuzzy controller keeps high utilization coefficient due to the optimal slip ratio regulation, and the total brake time has a smaller decrease than traditional hydraulic brake system.

  5. Anti-lock braking system (ABS) and regenerative braking system (RBS) in hybrid electric vehicle for smart transportation system

    Science.gov (United States)

    Evuri, Geetha Reddy; Rao, G. Srinivasa; Reddy, T. Ramasubba; Reddy, K. Srinivasa

    2018-04-01

    Pulse width modulation (PWM) based (a non-consistent) breaking system is used to keep the wheels from being bolted in the proposed antilock breaking system (ABS). Using this method a better hold of the street by wheels is possible and halting separations likewise diminish essentially particularly on precarious street surfaces like frosty or wet streets. The active vitality of the wheel is by and large lost amid braking as warmth because of grinding among brake cushions. This vitality can be recuperated using regenerative braking systems (RBS). In this strategy, the overabundance vitality is put away incidentally in capacitor banks before it gets changed over to warm vitality and is squandered. This framework delays the battery life by reviving the battery utilizing the put away vitality. Subsequently the mileage of the electric vehicle likewise increments as it can travel more separation in a solitary battery charge. These two techniques together help make electric vehicle vitality productive and more secure and less demanding to utilize subsequently anticipating and diminishing the quantity of mischance's.

  6. Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

    Directory of Open Access Journals (Sweden)

    Wenchuan Cai

    2014-01-01

    Full Text Available Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate the adhesion force or/and the resistance, based on which simple traction/braking control schemes are established under the consideration of actual wheel-rail adhesion condition. It is shown that the proposed controllers have simple structure and can be easily implemented from real applications. Numerical simulation also validates the effectiveness of the proposed control scheme.

  7. Determining the frequency of asbestos use in automotive brakes from a fleet of on-road California vehicles.

    Science.gov (United States)

    De Vita, Joseph; Wall, Stephen; Wagner, Jeff; Wang, Zhong-Min; Rao, Leela E

    2012-02-07

    Asbestos is a known human carcinogen, and recent regulation in California limits asbestiform fibers in brakes to trace levels beginning in 2014, although there is no corresponding federal requirement. In order to gauge the current prevalence of asbestos use in automotive brake applications, the California Air Resources Board tested brake linings from 137 light- and medium-duty vehicles and 54 heavy-duty vehicles. Only about 3% of the light- and medium-duty vehicle brake linings contained chrysotile asbestos. All of those brake linings were drum-type shoes, which are generally being phased out. No asbestos was found in low mileage vehicles presumed to have their original stock linings from the vehicle manufacturer. Additionally, no asbestos was found in the heavy-duty vehicle brake shoe linings sampled. Given the small percentage of vehicle brake linings with asbestos observed, it appears that the prior federal ban that was subsequently overturned, in combination with a threat of litigation, has reduced asbestos use in brake linings. However, our study was limited in scope and without a national ban, the current and future prevalence of asbestos in brakes is uncertain, suggesting the need for continued monitoring of materials released as toxic air contaminants in normal braking operations.

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

    Science.gov (United States)

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

    2017-09-01

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

  9. New evaluation methodology of regenerative braking contribution to energy efficiency improvement of electric vehicles

    International Nuclear Information System (INIS)

    Qiu, Chengqun; Wang, Guolin

    2016-01-01

    Highlights: • Two different contribution ratio evaluation parameters according to the deceleration braking process are proposed. • Methodologies for calculating the contribution made by regenerative brake to improve vehicle energy efficiency are proposed. • Road test results imply that the proposed parameters are effective. - Abstract: Comprehensive research is conducted on the design and control of a regenerative braking system for electric vehicles. The mechanism and evaluation methods of contribution brought by regenerative braking to improve electric vehicle’s energy efficiency are discussed and analyzed by the energy flow. Methodologies for calculating the contribution made by regenerative brake are proposed. Additionally a new regenerative braking control strategy called “serial 2 control strategy” is introduced. Moreover, two control strategies called “parallel control strategy” and “serial 1 control strategy” are proposed as the comparative control strategy. Furthermore, two different contribution ratio evaluation parameters according to the deceleration braking process are proposed. Finally, road tests are carried out under China typical city regenerative driving cycle standard with three different control strategies. The serial 2 control strategy offers considerably higher regeneration efficiency than the parallel strategy and serial 1 strategy.

  10. Intelligent Speed Adaptation in Company Vehicles

    DEFF Research Database (Denmark)

    Agerholm, Niels; Tradisauskas, Nerius; Waagepetersen, Rasmus

    2008-01-01

    This paper describes an intelligent speed adaptation project for company vehicles. The intelligent speed adaptation function in the project is both information and incentive, which means that the intelligent speed adaptation equipment gives a warning as well as penalty points if the driver...... is speeding. Each month the driver with that monthpsilas fewest points wins an award. The paper presents results concerning speed attitude on the first three of a planned 12 months test period. In all 26 vehicles and 51 drivers from six companies participate in the project. The key result is that speeding...

  11. Driver head displacement during (automatic) vehicle braking tests with varying levels of distraction

    OpenAIRE

    Rooij, L. van; Pauwelussen, J.; Camp, O.M.G.C. op den; Janssen, J.M.

    2013-01-01

    Vehicle occupant behavior in emergency driving conditions has a large effect on traffic safety. Distraction is estimated to be the cause of 15-20% of all crashes. Additionally, the posture of the occupants prior to the possibly unavoidable crash is known to have a large effect on the injury reducing performance of the restraint system. In this study it is investigated whether braking settings as well as driver distraction influence the kinematic response of an occupant during braking events, ...

  12. Effects of vehicle power on passenger vehicle speeds.

    Science.gov (United States)

    McCartt, Anne T; Hu, Wen

    2017-07-04

    During the past 2 decades, there have been large increases in mean horsepower and the mean horsepower-to-vehicle weight ratio for all types of new passenger vehicles in the United States. This study examined the relationship between travel speeds and vehicle power, defined as horsepower per 100 pounds of vehicle weight. Speed cameras measured travel speeds and photographed license plates and drivers of passenger vehicles traveling on roadways in Northern Virginia during daytime off-peak hours in spring 2013. The driver licensing agencies in the District of Columbia, Maryland, and Virginia provided vehicle information numbers (VINs) by matching license plate numbers with vehicle registration records and provided the age, gender, and ZIP code of the registered owner(s). VINs were decoded to obtain the curb weight and horsepower of vehicles. The study focused on 26,659 observed vehicles for which information on horsepower was available and the observed age and gender of drivers matched vehicle registration records. Log-linear regression estimated the effects of vehicle power on mean travel speeds, and logistic regression estimated the effects of vehicle power on the likelihood of a vehicle traveling over the speed limit and more than 10 mph over the limit. After controlling for driver characteristics, speed limit, vehicle type, and traffic volume, a 1-unit increase in vehicle power was associated with a 0.7% increase in mean speed, a 2.7% increase in the likelihood of a vehicle exceeding the speed limit by any amount, and an 11.6% increase in the likelihood of a vehicle exceeding the limit by 10 mph. All of these increases were highly significant. Speeding persists as a major factor in crashes in the United States. There are indications that travel speeds have increased in recent years. The current findings suggest the trend toward substantially more powerful vehicles may be contributing to higher speeds. Given the strong association between travel speed and crash

  13. Multi-objective optimization of the control strategy of electric vehicle electro-hydraulic composite braking system with genetic algorithm

    Directory of Open Access Journals (Sweden)

    Zhang Fengjiao

    2015-03-01

    Full Text Available Optimization of the control strategy plays an important role in improving the performance of electric vehicles. In order to improve the braking stability and recover the braking energy, a multi-objective genetic algorithm is applied to optimize the key parameters in the control strategy of electric vehicle electro-hydraulic composite braking system. Various limitations are considered in the optimization process, and the optimization results are verified by a software simulation platform of electric vehicle regenerative braking system in typical brake conditions. The results show that optimization objectives achieved a good astringency, and the optimized control strategy can increase the brake energy recovery effectively under the condition of ensuring the braking stability.

  14. 75 FR 5553 - Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids

    Science.gov (United States)

    2010-02-03

    ... NHTSA comments S6.2 Wet Equilibrium Boiling Point... Appendix E of SAE J1703 Appendix E of SAE J1703 No.... Definition of ``Brake Fluid'' To apply FMVSS No. 116 to brake fluid that contacts EPDM rubber, we propose to expand the definition of ``brake fluid'' at S4 of the standard to expressly state that ``brake fluid...

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

    Science.gov (United States)

    Zhu, Min; Chen, Huiyan; Xiong, Guangming

    2017-03-01

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

  16. Regenerative braking strategies, vehicle safety and stability control systems: critical use-case proposals

    Science.gov (United States)

    Oleksowicz, Selim A.; Burnham, Keith J.; Southgate, Adam; McCoy, Chris; Waite, Gary; Hardwick, Graham; Harrington, Cian; McMurran, Ross

    2013-05-01

    The sustainable development of vehicle propulsion systems that have mainly focused on reduction of fuel consumption (i.e. CO2 emission) has led, not only to the development of systems connected with combustion processes but also to legislation and testing procedures. In recent years, the low carbon policy has made hybrid vehicles and fully electric vehicles (H/EVs) popular. The main virtue of these propulsion systems is their ability to restore some of the expended energy from kinetic movement, e.g. the braking process. Consequently new research and testing methods for H/EVs are currently being developed. This especially concerns the critical 'use-cases' for functionality tests within dynamic events for both virtual simulations, as well as real-time road tests. The use-case for conventional vehicles for numerical simulations and road tests are well established. However, the wide variety of tests and their great number (close to a thousand) creates a need for selection, in the first place, and the creation of critical use-cases suitable for testing H/EVs in both virtual and real-world environments. It is known that a marginal improvement in the regenerative braking ratio can significantly improve the vehicle range and, therefore, the economic cost of its operation. In modern vehicles, vehicle dynamics control systems play the principal role in safety, comfort and economic operation. Unfortunately, however, the existing standard road test scenarios are insufficient for H/EVs. Sector knowledge suggests that there are currently no agreed tests scenarios to fully investigate the effects of brake blending between conventional and regenerative braking as well as the regenerative braking interaction with active driving safety systems (ADSS). The paper presents seven manoeuvres, which are considered to be suitable and highly informative for the development and examination of H/EVs with regenerative braking capability. The critical manoeuvres presented are considered to be

  17. Design and research on the electronic parking brake system of the medium and heavy duty vehicles

    Directory of Open Access Journals (Sweden)

    Hongliang WANG

    2015-04-01

    Full Text Available Focusing on auto control of parking brake system of the medium and heavy duty vehicles, the key problems are studied including the system design and control strategies. The structure and working principle of the parking brake system of the medium and heavy duty vehicles are analyzed. The functions of EPB are proposed. The important information of the vehicle are analyzed which could influence the EPB system. The overall plan of the pneumatic EPB system is designed, which adopts the two-position three-way electromagnetic valve with double coil as actuator. The system could keep the vehicle parking brake status or parking release status for a long time without power supply. The function modules of the system are planned, and the control strategies of automatic parking brake and parking release are made. The experiment is performed on a medium-sized commercial vehicle which is experimentally modified. The overall plan of the pneumatic EPB system and the automatic parking function are proved through real vehicle tests.

  18. Straight motion gear for vehicle brakes with electrical actuation; Translationsgetriebe fuer elektrisch betaetigte Fahrzeugbremsen

    Energy Technology Data Exchange (ETDEWEB)

    Bill, K.H.; Semsch, M. [Technische Univ. Darmstadt (Germany). Fachgebiet Fahrzeugtechnik

    1998-01-01

    Electric brake systems and components are increasing in importance due to the easy wheel-selective operation in future vehicle concepts. Building electric brake systems economically is decisively dependent on the availability of wheel brakes suitable in terms of dynamic behaviour, energy requirements, space, size, reliability and costs. In particular, the coupling of the transducer and friction brake by means of a suitable gear system adapted to the requirements of a vehicle brake represents a problem which has not yet been satisfactorily solved. In Subproject B6 of the Sonderforschungsbereich 241-IMES, sponsored by the Deutsche Forschungsgemeinschaft, research on new mechatronic brake systems is being conducted at the Automotive Engineering Department of Darmstadt University. (orig.) [Deutsch] Elektrische Bremssysteme und Komponenten gewinnen durch den leicht durchfuehrbaren radselektiven Eingriff bei kuenftigen Fahrzeugkonzepten eine zunehmende Bedeutung. Die wirtschaftliche Realisierung elektrischer Bremssysteme wird massgeblich von der Verfuegbarkeit geeigneter Radbremsen im Hinblick auf Dynamikverhalten, Energiebedarf, Bauraum, Masse, Zuverlaessigkeit und Kosten abhaengen. Besonders die Kopplung von Autor und Reibungsbremse durch ein geeignetes, an die Erfordernisse einer Fahrzeugbremse angepasstes Getriebesystem stellt ein bisher noch nicht befriedigend geloestes Problem dar. Im Teilprojekt B6 des Sonderforschungsbereiches 241-IMES, gefoerdert durch die Deutsche Forschungsgemeinschaft, werden hierzu an der Technischen Universitaet Darmstadt (TUD), Fachgebiet Fahrzeugtechnik, mechatronische Bremssysteme entwickelt. (orig.)

  19. End effect braking force reduction in high-speed single-sided linear induction machine

    International Nuclear Information System (INIS)

    Shiri, Abbas; Shoulaie, Abbas

    2012-01-01

    Highlights: ► A new analytical equation to model the end effect braking force of SLIM is derived. ► Equations for efficiency, power factor and output thrust are analytically derived. ► The effect of design variables on the performance of the motor is analyzed. ► An optimization method is employed to minimize the end effect braking force (EEBF). ► The results show that EEBF is minimized by appropriate selection of motor parameters. - Abstract: Linear induction motors have been widely employed in industry because of their simple structure and low construction cost. However, they suffer from low efficiency and power factor. In addition, existence of so called end effect influences their performance especially in high speeds. The end effect deteriorates the performance of the motor by producing braking force. So, in this paper, by using Duncan equivalent circuit model, a new analytical equation is proposed to model end effect braking force. Employing the proposed equation and considering all phenomena involved in the single-sided linear induction motor, a simple design procedure is presented and the effect of different design variables on the performance of the motor is analyzed. A multi-objective optimization method based on genetic algorithm is introduced to maximize efficiency and power factor, as well as to minimize the end effect braking force, simultaneously. Finally, to validate the optimization results, 2D finite element method is employed.

  20. INVESTIGATION OF VEHICLE WHEEL ROLLING WITH MAXIMUM EFFICIENCY IN THE BRAKE MODE

    Directory of Open Access Journals (Sweden)

    D. Leontev

    2011-01-01

    Full Text Available Up-to-date vehicles are equipped by various systems of braking effort automatic control theparameters calculation of which do not as a rule have a rational solution. In order to increase theworking efficiency of such systems it is necessary to have the data concerning the impact of variousoperational factors on processes occurring at braking of the object of adjustment (vehicle wheel.Data availability concerning the impact of operational factors allows to decrease geometricalparameters of adjustment devices (modulators and maintain their efficient operation under variousexploitation conditions of vehicle’s motion.

  1. Assessment and preliminary design of an energy buffer for regenerative braking in electric vehicles

    Science.gov (United States)

    Buchholz, R.; Mathur, A. K.

    1979-01-01

    Energy buffer systems, capable of storing the vehicle energy during braking and reusing this stored energy during acceleration, were examined. Some of these buffer systems when incorporated in an electric vehicle would result in an improvement in the performance and range under stop and go driving conditions. Buffer systems considered included flywheels, hydropneumatic, pneumatic, spring, and regenerative braking. Buffer ranking and rating criteria were established. Buffer systems were rated based on predicted range improvements, consumer acceptance, driveability, safety, reliability and durability, and initial and life cycle costs. A hydropneumatic buffer system was selected.

  2. Regenerative Braking Control Strategy of Electric-Hydraulic Hybrid (EHH Vehicle

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2017-07-01

    Full Text Available A novel electric-hydraulic hybrid drivetrain incorporating a set of hydraulic systems is proposed for application in a pure electric vehicle. Models of the electric and hydraulic components are constructed. Two control strategies, which are based on two separate rules, are developed; the maximum energy recovery rate strategy adheres to the rule of the maximization of the braking energy recovery rate, while the minimum current impact strategy adheres to the rule of the minimization of the charge current to the battery. The simulation models were established to verify the effects of these two control strategies. An ABS (Anti-lock Braking System fuzzy control strategy is also developed and simulated. The simulation results demonstrate that the developed control strategy can effectively absorb the braking energy, suppress the current impact, and assure braking safety.

  3. Design and analysis of magneto rheological fluid brake for an all terrain vehicle

    Science.gov (United States)

    George, Luckachan K.; Tamilarasan, N.; Thirumalini, S.

    2018-02-01

    This work presents an optimised design for a magneto rheological fluid brake for all terrain vehicles. The actuator consists of a disk which is immersed in the magneto rheological fluid surrounded by an electromagnet. The braking torque is controlled by varying the DC current applied to the electromagnet. In the presence of a magnetic field, the magneto rheological fluid particle aligns in a chain like structure, thus increasing the viscosity. The shear stress generated causes friction in the surfaces of the rotating disk. Electromagnetic analysis of the proposed system is carried out using finite element based COMSOL multi-physics software and the amount of magnetic field generated is calculated with the help of COMSOL. The geometry is optimised and performance of the system in terms of braking torque is carried out. Proposed design reveals better performance in terms of braking torque from the existing literature.

  4. Energy recapture through deceleration - regenerative braking in electric vehicles from a user perspective.

    Science.gov (United States)

    Cocron, Peter; Bühler, Franziska; Franke, Thomas; Neumann, Isabel; Dielmann, Benno; Krems, Josef F

    2013-01-01

    We report results from a 1-year field study (N = 80) on user interactions with regenerative braking in electric vehicles. Designed to recapture energy in vehicles with electric powertrains, regenerative braking has an important influence on both the task of driving and energy consumption. Results from user assessments and data from onboard data loggers indicate that most drivers quickly learned to interact with the system, which was triggered via accelerator. Further, conventional braking manoeuvres decreased significantly as the majority of deceleration episodes could only be executed through regenerative braking. Still, some drivers reported difficulties when adapting to the system. These difficulties could be addressed by offering different levels of regeneration so that the intensity of the deceleration could be individually modified. In general, the system is trusted and regarded as a valuable tool for prolonging range. Regenerative braking in electric vehicles has direct implications for the driving task. We found that drivers quickly learn to use and accept a system, which is triggered via accelerator. For those reporting difficulties in the interaction, it appears reasonable to integrate options to customise or switch off the system.

  5. The design of brake fatigue testing system

    Directory of Open Access Journals (Sweden)

    Huang, Xiaoya

    2015-01-01

    Full Text Available Brake is used to reduce the operating speed of the machinery equipment or to make it stop. It is essential for vehicles, climbing machines and many fixed equipment in their safety work. Brake tester is an experimental apparatus to measure and analyse the braking performance. Based on the PLC technology and for the purpose of testing brake shoe friction material’s life, this paper designed a virtual brake test platform. In it, inverter were used to control the motor, so that it can load automatically and ensure brake drum constant speed output; what is more, closed loop control system were used to control the brake shoe, so that the cylinder pressure keeps stable in the process of dynamic braking.

  6. Designing neuro-fuzzy controller for electromagnetic anti-lock braking system (ABS) on electric vehicle

    Science.gov (United States)

    Pramudijanto, Josaphat; Ashfahani, Andri; Lukito, Rian

    2018-03-01

    Anti-lock braking system (ABS) is used on vehicles to keep the wheels unlocked in sudden break (inside braking) and minimalize the stop distance of the vehicle. The problem of it when sudden break is the wheels locked so the vehicle steering couldn’t be controlled. The designed ABS system will be applied on ABS simulator using the electromagnetic braking. In normal condition or in condition without braking, longitudinal velocity of the vehicle will be equal with the velocity of wheel rotation, so the slip ratio will be 0 (0%) and if the velocity of wheel rotation is 0 (in locked condition) then the wheels will be slip 1 (100%). ABS system will keep the value of slip ratio so it will be 0.2 (20%). In this final assignment, the method that is used is Neuro-Fuzzy method to control the slip value on the wheels. The input is the expectable slip and the output is slip from plant. The learning algorithm which is used is Backpropagation that will work by feedforward to get actual output and work by feedback to get error value with target output. The network that was made based on fuzzy mechanism which are fuzzification, inference and defuzzification, Neuro-fuzzy controller can reduce overshoot plant respond to 43.2% compared to plant respond without controller by open loop.

  7. New technical solutions of using rolling stock electrodynamical braking

    Directory of Open Access Journals (Sweden)

    Leonas Povilas LINGAITIS

    2009-01-01

    Full Text Available The paper considers some theoretical and practical problems associated with the use of traction motor are operating in the generator mode (in braking. Mathematical and graphical relationships of electrodynamic braking, taking into account the requirements raised to braking systems in rail transport are presented. The latter include discontinuity of braking process, braking force regulation, depending on the locomotive speed, mass, type of railway and other parameters. Schematic diagrams of the locomotive braking and ways of controlling the braking force by varying electric circuit parameters are presented. The authors suggested contact-free regulation method of braking resistor for controlling braking force in rheostatic braking, and resistor parameters regulate with pulse regulation mode by semiconductor devices, such as new electrical components for rolling stock – IGBT transistors operating in the key mode. Presenting energy savings power systems, which are using regenerative braking-returning energy and diesel engine or any form of hybrid traction vehicles systems, circuit diagrams, electrical parameters curves.

  8. Multiple-Vehicle Longitudinal Collision Mitigation by Coordinated Brake Control

    Directory of Open Access Journals (Sweden)

    Xiao-Yun Lu

    2014-01-01

    Full Text Available Rear-end collision often leads to serious casualties and traffic congestion. The consequences are even worse for multiple-vehicle collision. Many previous works focused on collision warning and avoidance strategies of two consecutive vehicles based on onboard sensor detection only. This paper proposes a centralized control strategy for multiple vehicles to minimize the impact of multiple-vehicle collision based on vehicle-to-vehicle communication technique. The system is defined as a coupled group of vehicles with wireless communication capability and short following distances. The safety relationship can be represented as lower bound limit on deceleration of the first vehicle and upper bound on maximum deceleration of the last vehicle. The objective is to determine the desired deceleration for each vehicle such that the total impact energy is minimized at each time step. The impact energy is defined as the relative kinetic energy between a consecutive pair of vehicles (approaching only. Model predictive control (MPC framework is used to formulate the problem to be constrained quadratic programming. Simulations show its effectiveness on collision mitigation. The developed algorithm has the potential to be used for progressive market penetration of connected vehicles in practice.

  9. Personal exposures to asbestos fibers during brake maintenance of passenger vehicles.

    Science.gov (United States)

    Cely-García, María Fernanda; Sánchez, Mauricio; Breysse, Patrick N; Ramos-Bonilla, Juan P

    2012-11-01

    Brake linings and brake pads are among the asbestos-containing products that are readily available in Colombia. When sold separated from their support, brake linings require extensive manipulation involving several steps that include drilling, countersinking, riveting, bonding, cutting, beveling, and grinding. Without this manipulation, brake linings cannot be installed in a vehicle. The manipulation process may release asbestos fibers, which may expose brake mechanics to the fibers. Three brake repair shops located in Bogotá (Colombia) were sampled for 3 or 4 consecutive days using US National Institute for Occupational Safety and Health (NIOSH) methods 7400 and 7402. Standard procedures for quality control were followed during the sampling process, and asbestos samples were analyzed by an American Industrial Hygiene Association accredited laboratory. Personal samples were collected to assess full-shift and short-term exposures. Area samples were also collected close to the brake-lining manipulation equipment and within office facilities. Activities were documented during the sampling process. Using Phase Contrast Microscopy Equivalent counts to estimate air asbestos concentrations, all personal samples [i.e. 8-h time-weighted averages (TWAs) and 30-min personal samples] were in compliance with the US Occupational Safety and Health Administration standards. Personal asbestos concentrations based on transmission electron microscopy counts were extremely high, ranging from 0.006 to 3.493 f cm(-3) for 8-h TWA and from 0.015 to 8.835 f cm(-3) for 30-min samples. All asbestos fibers detected were chrysotile. Cleaning facilities and grinding linings resulted in the highest asbestos exposures based on transmission electron microscopy counts. There were also some samples that did not comply with the NIOSH's recommended exposure limits. The results indicate that the brake mechanics sampled are exposed to extremely high asbestos concentrations (i.e. based on transmission

  10. Energy Efficiency in Heavy Vehicle Tires, Drivetrains, and Braking Systems; FINAL

    International Nuclear Information System (INIS)

    Peter J. Blau

    2000-01-01

    This document was prepared to support the primary goals of the Department of Energy, Office of Heavy Vehicle Technologies. These were recently stated as follows: ''Develop by 2004 the enabling technologies for a class 7-8 truck with a fuel efficiency of 10 mpg (at 65 mph) which will meet prevailing emission standards. For Class 3-6 trucks operating on an urban driving cycle, develop by 2004 commercially viable vehicles that achieve at least double the fuel economy of comparable current vehicles (1999), and as a research goal, reduce criteria pollutants to 30% below EPA standards. Develop by 2004 the diesel engine enabling technologies to support large-scale industry dieselization of Class 1 and 2 trucks, achieving a 35% fuel efficiency improvement over comparable gasoline-fueled trucks, while meeting applicable emissions standards.'' The enabling technologies for improving the fuel efficiency of trucks, include not only engine technologies but also technologies involved with lowering the rolling resistance of tires, reducing vehicle aerodynamic drag, improving thermal management, and reducing parasitic frictional losses in drive train components. Opportunities also exist for making better use of the energy that might ordinarily be dissipated during vehicle braking. Braking systems must be included in this evaluation since safety in truck operations is vital, and braking requirements are greater for vehicles having lowered resistance to rolling. The Office of Heavy Vehicle Technologies has initiated a program to improve the aerodynamics of heavy vehicles through wind tunnel testing, computational modeling, and on-road evaluations. That activity is described in a separate multi-year plan; therefore, emphasis in this document will be on tires, drive trains, and braking systems. Recent, dramatic fluctuations in diesel fuel prices have emphasized the importance of effecting savings in truck fuel economy by implementing new component designs and materials

  11. The Effect of a Variable Disc Pad Friction Coefficient for the Mechanical Brake System of a Railway Vehicle.

    Science.gov (United States)

    Lee, Nam-Jin; Kang, Chul-Goo

    2015-01-01

    A brake hardware-in-the-loop simulation (HILS) system for a railway vehicle is widely applied to estimate and validate braking performance in research studies and field tests. When we develop a simulation model for a full vehicle system, the characteristics of all components are generally properly simplified based on the understanding of each component's purpose and interaction with other components. The friction coefficient between the brake disc and the pad used in simulations has been conventionally considered constant, and the effect of a variable friction coefficient is ignored with the assumption that the variability affects the performance of the vehicle braking very little. However, the friction coefficient of a disc pad changes significantly within a range due to environmental conditions, and thus, the friction coefficient can affect the performance of the brakes considerably, especially on the wheel slide. In this paper, we apply a variable friction coefficient and analyzed the effects of the variable friction coefficient on a mechanical brake system of a railway vehicle. We introduce a mathematical formula for the variable friction coefficient in which the variable friction is represented by two variables and five parameters. The proposed formula is applied to real-time simulations using a brake HILS system, and the effectiveness of the formula is verified experimentally by testing the mechanical braking performance of the brake HILS system.

  12. The Effect of a Variable Disc Pad Friction Coefficient for the Mechanical Brake System of a Railway Vehicle

    Science.gov (United States)

    Lee, Nam-Jin; Kang, Chul-Goo

    2015-01-01

    A brake hardware-in-the-loop simulation (HILS) system for a railway vehicle is widely applied to estimate and validate braking performance in research studies and field tests. When we develop a simulation model for a full vehicle system, the characteristics of all components are generally properly simplified based on the understanding of each component’s purpose and interaction with other components. The friction coefficient between the brake disc and the pad used in simulations has been conventionally considered constant, and the effect of a variable friction coefficient is ignored with the assumption that the variability affects the performance of the vehicle braking very little. However, the friction coefficient of a disc pad changes significantly within a range due to environmental conditions, and thus, the friction coefficient can affect the performance of the brakes considerably, especially on the wheel slide. In this paper, we apply a variable friction coefficient and analyzed the effects of the variable friction coefficient on a mechanical brake system of a railway vehicle. We introduce a mathematical formula for the variable friction coefficient in which the variable friction is represented by two variables and five parameters. The proposed formula is applied to real-time simulations using a brake HILS system, and the effectiveness of the formula is verified experimentally by testing the mechanical braking performance of the brake HILS system. PMID:26267883

  13. Regression Test on the Rotational Speed between Two Loads as the Preparation for Braking System

    International Nuclear Information System (INIS)

    Purwanti, B S R; Yusivar, F; Garniwa M K, I

    2013-01-01

    This paper is preparing the mathematic model of braking control, continuously of determination the error (e), delta error (de) of speed reduction [9]. Load-1 and Load-2 are driven by an electric motor located on the same shaft. Both loads are driven clock wise (CW), counter clock wise (CCW) by an asynchronous three-phase motor (M3). The mass of each load is also differentiated to simulate slip phenomena. Rotational speed of M3 is equal to Load-1, detected by Sensor-1, while speed rotation of Load-2 is detected by Sensor-2. The rotation for Load-1 and Load-2 can be adjusted on several position H j (j = 1, 2, 3). Once Load-1 and Load-2 reach a constant speed, current source will be disconnected. Speed reduction from (ω±1475 rpm) to stagnant (ω=0 rpm) on Load-1 and Load-2 is considered time function. Data collected from both load (ω (t)) known as e, de; on each position of H j . It uses covariance analysis to make sure that both loads are concurrent with each other against time difference. The objective of this research is to determine slip phenomena of speed reduction of each load. The expectations are to generate smoother braking and minimize the time needed when implemented with ANFIS.

  14. Robust Switched Predictive Braking Control for Rollover Prevention in Wheeled Vehicles

    Directory of Open Access Journals (Sweden)

    Martín Antonio Rodríguez Licea

    2014-01-01

    Full Text Available The aim of this paper is to propose a differential braking rollover mitigation strategy for wheeled vehicles. The strategy makes use of a polytopic (piecewise linear description of the vehicle and includes translational and rotational dynamics, as well as suspension effects. The braking controller is robust and the system states are predicted to estimate the rollover risk up to a given time horizon. In contrast to existing works, the switched predictive nature of the control allows it to be applied only when risk of rollover is foreseen, interfering a minimum with driver’s actions. The stability of the strategy is analyzed and its robustness is illustrated via numerical simulations using CarSim for a variety of vehicles.

  15. Thermal response of an aeroassisted orbital-transfer vehicle with a conical drag brake

    Science.gov (United States)

    Pitts, W. C.; Murbach, M. S.

    1984-01-01

    As an aeroassisted orbital-transfer vehicle (AOTV) goes through an aerobraking maneuver, a significant amount of heat is generated. In this paper, the thermal response of a specific AOTV to this aerobrake heating is examined. The vehicle has a 70 deg, conical drag-brake heat shield attached to a cylindrical body which contains the payload. The heat shield is made of silica fabric. The heat-shield thickness is varied from that of a thin cloth to a 1.5-cm blanket. The fabric thickness, the radiation absorptivity of the vehicle surface materials, and radiation from the wake are all significant parameters in the thermal response to the heating produced by the braking maneuver. The maximum temperatures occur in the vicinity of the interface between the body and the conical heat shield.

  16. Thermal Response of an Aeroassisted Orbital Transfer Vehicle with a Conical Drag Brake

    Science.gov (United States)

    Pitts, W. C.; Murbach, M. S.

    1985-01-01

    As an aeroassisted orbital transfer vehicle (AOTV) goes through an aerobraking maneuver a significant amount of heat is generated. In this paper, the thermal response of a specific AOTV to this aerobrake heating is examined. The vehicle has a 70-deg, Conical drag-brake heat shield attached to a cylindrical body which contains the payload. The heat shield is made of ceramic fabric its thickness is varied from that of a thin cloth to a 1.5-cm blanket. The fabric thickness, the radiation absorptivity of the vehicle surface materials, and radiation from the wake are all significant parameters in the thermal response to the heating produced by the braking maneuver. The maximum temperatures occur In the vicinity of the interface between the body and the conical heat shield.

  17. Performance Evaluation of an Anti-Lock Braking System for Electric Vehicles with a Fuzzy Sliding Mode Controller

    Directory of Open Access Journals (Sweden)

    Jingang Guo

    2014-10-01

    Full Text Available Traditional friction braking torque and motor braking torque can be used in braking for electric vehicles (EVs. A sliding mode controller (SMC based on the exponential reaching law for the anti-lock braking system (ABS is developed to maintain the optimal slip value. Parameter optimizing is applied to the reaching law by fuzzy logic control (FLC. A regenerative braking algorithm, in which the motor torque is taken full advantage of, is adopted to distribute the braking force between the motor braking and the hydraulic braking. Simulations were carried out with Matlab/Simulink. By comparing with a conventional Bang-bang ABS controller, braking stability and passenger comfort is improved with the proposed SMC controller, and the chatting phenomenon is reduced effectively with the parameter optimizing by FLC. With the increasing proportion of the motor braking torque, the tracking of the slip ratio is more rapid and accurate. Furthermore, the braking distance is shortened and the conversion energy is enhanced.

  18. A Predictive Distribution Model for Cooperative Braking System of an Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Hongqiang Guo

    2014-01-01

    Full Text Available A predictive distribution model for a series cooperative braking system of an electric vehicle is proposed, which can solve the real-time problem of the optimum braking force distribution. To get the predictive distribution model, firstly three disciplines of the maximum regenerative energy recovery capability, the maximum generating efficiency and the optimum braking stability are considered, then an off-line process optimization stream is designed, particularly the optimal Latin hypercube design (Opt LHD method and radial basis function neural network (RBFNN are utilized. In order to decouple the variables between different disciplines, a concurrent subspace design (CSD algorithm is suggested. The established predictive distribution model is verified in a dynamic simulation. The off-line optimization results show that the proposed process optimization stream can improve the regenerative energy recovery efficiency, and optimize the braking stability simultaneously. Further simulation tests demonstrate that the predictive distribution model can achieve high prediction accuracy and is very beneficial for the cooperative braking system.

  19. Advanced Ceramic-Metallic Composites for Lightweight Vehicle Braking Systems

    Science.gov (United States)

    2012-09-11

    According to the Federal Transit Administration Strategic Research Plan [1]: Researching technologies to reduce vehicle weight can also lead to important reductions in fuel consumption and emissions. The power required to accelerate a bus and over...

  20. Extended-Kalman-filter-based regenerative and friction blended braking control for electric vehicle equipped with axle motor considering damping and elastic properties of electric powertrain

    Science.gov (United States)

    Lv, Chen; Zhang, Junzhi; Li, Yutong

    2014-11-01

    Because of the damping and elastic properties of an electrified powertrain, the regenerative brake of an electric vehicle (EV) is very different from a conventional friction brake with respect to the system dynamics. The flexibility of an electric drivetrain would have a negative effect on the blended brake control performance. In this study, models of the powertrain system of an electric car equipped with an axle motor are developed. Based on these models, the transfer characteristics of the motor torque in the driveline and its effect on blended braking control performance are analysed. To further enhance a vehicle's brake performance and energy efficiency, blended braking control algorithms with compensation for the powertrain flexibility are proposed using an extended Kalman filter. These algorithms are simulated under normal deceleration braking. The results show that the brake performance and blended braking control accuracy of the vehicle are significantly enhanced by the newly proposed algorithms.

  1. Vehicle speed control using road bumps

    Directory of Open Access Journals (Sweden)

    T. A. O. Salau

    2004-06-01

    Full Text Available Road bumps play a crucial role in enforcing speed limits, thereby preventing overspeeding of vehicles. It significantly contributes to the overall road safety objective through the prevention of accidents that lead to deaths of pedestrians and damage of vehicles. Despite the importance of road bumps, very little research has been done to investigate into their design. While documentation exists on quantitative descriptions of road bumps, they offer little guidance to decision making. This work presents a unique approach to solving road bumps design problems. The results of our study reveal three important road bumps variables that influence the control of vehicle speeds. The key variables are bump height, bump width, and effective distance between two consecutive road bumps. Since vehicle speed control is the ultimate aim of this study the relationship between vehicle speed and other variables earlier mentioned is established. Vehicle speed is defined as the product of frequency at which a vehicle is moving over road bumps and the sum of effective distance between two consecutive road bumps. In the determination of bump height we assume a conical shaped curve for analysis as a matter of research strategy. Based on this, two stages of motion were analysed. The first concerns the motion over the bump itself while the second relates to the motion between two consecutive road bumps. Fourier series was then used to formulate a holistic equation that combines these two stages. We used trigonometric functions to model the behaviour of the first stage while with the second stage giving a functional value of zero since no changes in height are observed. We carried out vibration analysis to determine the effect of road bumps on a vehicular system. Arising from this a model component is referred to as an isolation factor. This offers guidance to the safe frequency at which vehicles could travel over road bumps. The work appears to contribute to knowledge

  2. 30 CFR 56.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

    ... which is not originally equipped with brakes unless the manner in which the equipment is being operated...; (2) The performance of the service brakes shall be evaluated according to Table M-1. Table M-1 Gross... values include a one-second operator response time. Table M-2—The Speed of a Vehicle Can be Determined by...

  3. Transient fault tolerant control for vehicle brake-by-wire systems

    International Nuclear Information System (INIS)

    Huang, Shuang; Zhou, Chunjie; Yang, Lili; Qin, Yuanqing; Huang, Xiongfeng; Hu, Bowen

    2016-01-01

    Brake-by-wire (BBW) systems that have no mechanical linkage between the brake pedal and the brake mechanism are expected to improve vehicle safety through better braking capability. However, transient faults in BBW systems can cause dangerous driving situations. Most existing research in this area focuses on the brake control mechanism, but very few studies try to solve the problem associated with transient fault propagation and evolution in the brake control system hierarchy. In this paper, a hierarchical transient fault tolerant scheme with embedded intelligence and resilient coordination for BBW system is proposed based on the analysis of transient fault propagation characteristics. In this scheme, most transient faults are tackled rapidly by a signature-based detection method at the node level, and the remaining transient faults, which cannot be detected directly at the node level and could degrade the system performance through fault propagation and evolution, are detected and recovered through function and structure models at the system level. To jointly accommodate these BBW transient faults at the system level, a sliding mode control algorithm and a task reallocation strategy are designed. A simulation platform based on Architecture Analysis and Design Language (AADL) is established to evaluate the task reallocation strategy, and a hardware-in-the-loop simulation is carried out to validate the proposed scheme systematically. Experimental results show the effectiveness of this new approach to BBW systems. - Highlights: • We propose a hierarchical transient fault tolerant scheme for BBW systems. • A sliding mode algorithm and a task strategy are designed to tackle transient fault. • The effectiveness of the scheme is verified in both simulation and HIL environments.

  4. Novel control algorithm of braking energy regeneration system for an electric vehicle during safety–critical driving maneuvers

    International Nuclear Information System (INIS)

    Lv, Chen; Zhang, Junzhi; Li, Yutong; Yuan, Ye

    2015-01-01

    Highlights: • Models of an electric vehicle with regenerative braking system (RBS) are built. • Control algorithm of RBS under safety–critical driving maneuvers is proposed. • Simulations and HIL tests of the proposed strategy are conducted. • Performance improvement of vehicle’s mean deceleration is up to 13.89%. • Test results verify the feasibility and effectiveness of the proposed method. - Abstract: This paper mainly focuses on control algorithm of the braking energy regeneration system of an electric bus under safety–critical driving situations. With the aims of guaranteeing vehicle stability in various types of tyre–road adhesion conditions, based on the characteristics of electrified powertrain, a novel control algorithm of regenerative braking system is proposed for electric vehicles during anti-lock braking procedures. First, the models of vehicle dynamics and main components including braking energy regenerative system of the case-study electric bus are built in MATLAB/Simulink. Then, based on the phase-plane method, the optimal brake torque is calculated for ABS control of vehicle. Next, a novel allocation strategy, wherein the target optimal brake torque is divided into two parts that are handled separately by the regenerative and friction brakes, is developed. Simulations of the proposed control strategy are conducted based on system models built using MATLAB/Simulink. The simulation results demonstrate that the developed strategy enables improved control in terms of vehicle stability and braking performance under different emergency driving conditions. To further verify the synthesized control algorithm, hardware-in-the-loop tests are also performed. The experimental results validate the simulation data and verify the feasibility and effectiveness of the developed control algorithm.

  5. Automotive Brake Systems.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    This correspondence course, orginally developed for the Marine Corps, is designed to provide mechanics with an understanding of the basic operations of automotive brake systems on military vehicles. The course contains four study units covering hydraulic brakes, air brakes, power brakes, and auxiliary brake systems. A troubleshooting guide for…

  6. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Science.gov (United States)

    2012-08-24

    ... motorcycle braking regulations from around the world, including the U.S. motorcycle brake systems standard.... Partial Failure Test--Split Service Brake System I. Power-Assisted Braking System Failure Test V. Other... motorcycle brake system technologies. In order to address modern braking technologies, the agency sought to...

  7. Advanced Emergency Braking Control Based on a Nonlinear Model Predictive Algorithm for Intelligent Vehicles

    Directory of Open Access Journals (Sweden)

    Ronghui Zhang

    2017-05-01

    Full Text Available Focusing on safety, comfort and with an overall aim of the comprehensive improvement of a vision-based intelligent vehicle, a novel Advanced Emergency Braking System (AEBS is proposed based on Nonlinear Model Predictive Algorithm. Considering the nonlinearities of vehicle dynamics, a vision-based longitudinal vehicle dynamics model is established. On account of the nonlinear coupling characteristics of the driver, surroundings, and vehicle itself, a hierarchical control structure is proposed to decouple and coordinate the system. To avoid or reduce the collision risk between the intelligent vehicle and collision objects, a coordinated cost function of tracking safety, comfort, and fuel economy is formulated. Based on the terminal constraints of stable tracking, a multi-objective optimization controller is proposed using the theory of non-linear model predictive control. To quickly and precisely track control target in a finite time, an electronic brake controller for AEBS is designed based on the Nonsingular Fast Terminal Sliding Mode (NFTSM control theory. To validate the performance and advantages of the proposed algorithm, simulations are implemented. According to the simulation results, the proposed algorithm has better integrated performance in reducing the collision risk and improving the driving comfort and fuel economy of the smart car compared with the existing single AEBS.

  8. 30 CFR 57.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

    ... which is not originally equipped with brakes unless the manner in which the equipment is being operated... evaluated according to Table M-1. Table M-1 Gross vehicle weight lbs. Equipment Speed, MPH 10 11 12 13 14 15... response time. Table M-2—The Speed of a Vehicle Can Be Determined by Clocking It Through a 100-Foot...

  9. M1078 Hybrid Hydraulic Vehicle Fuel Economy Evaluation

    Science.gov (United States)

    2012-09-01

    hydraulic energy stored in the accumulators. Park Mechanism Not Required – Vehicle air brake system used to immobilize vehicle when parked – Same...power to the transmission to accelerate the vehicle forward and maintain a desired speed. For regenerative braking , the switching valve is set to...assist, brake energy recovery, dual mode braking ( regenerative and service brakes ), engine stop/start, silent watch mode, and stationary tool use

  10. Analysis of torque transmitting behavior and wheel slip prevention control during regenerative braking for high speed EMU trains

    Science.gov (United States)

    Xu, Kun; Xu, Guo-Qing; Zheng, Chun-Hua

    2016-04-01

    The wheel-rail adhesion control for regenerative braking systems of high speed electric multiple unit trains is crucial to maintaining the stability, improving the adhesion utilization, and achieving deep energy recovery. There remain technical challenges mainly because of the nonlinear, uncertain, and varying features of wheel-rail contact conditions. This research analyzes the torque transmitting behavior during regenerative braking, and proposes a novel methodology to detect the wheel-rail adhesion stability. Then, applications to the wheel slip prevention during braking are investigated, and the optimal slip ratio control scheme is proposed, which is based on a novel optimal reference generation of the slip ratio and a robust sliding mode control. The proposed methodology achieves the optimal braking performance without the wheel-rail contact information. Numerical simulation results for uncertain slippery rails verify the effectiveness of the proposed methodology.

  11. Signal Processing for MoC brake rattle noise of moving vehicles using prony analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Cheol; Kwak, Yun Sang; Park, Jun Hong [Dept. of Mechanical Convergence Engineering, Hanyang University, Seoul (Korea, Republic of)

    2015-08-15

    To verify the possibility of generating rattling noise from a motor on caliper brake system, a test was conducted using a caliper excited with vibrations similar to that in a vehicle running on actual roads; this test was conducted using a quiet shaker installed in an anechoic room. After several hours of external excitation, the test assembly was loosened, and the frequency of rattling noise generation increased. A microphone was used to record the generated noise. The measured signals were analyzed by conventional spectrum analysis. Since the noise is generated as an impact response, the advantages of employing Prony analysis was discussed, and the results were compared to those obtained using conventional fast Fourier transforms. The accuracy of Prony analysis was through endurance tests on different brake systems.

  12. Literature review on vehicle travel speeds and pedestrian injuries

    Science.gov (United States)

    1999-10-01

    The relationship between vehicle travel speeds and resulting pedestrian injury was reviewed in the literature and in existing data sets. Results indicated that higher vehicle speeds are strongly associated with both a greater likelihood of pedestrian...

  13. Effect of energy-regenerative braking on electric vehicle battery thermal management and control method based on simulation investigation

    International Nuclear Information System (INIS)

    Huang, Jingying; Qin, Datong; Peng, Zhiyuan

    2015-01-01

    Highlights: • A two-degree-of-freedom lumped thermal model is developed for battery. • The battery thermal model is integrated with vehicle driving model. • Real-time battery thermal responses is obtained. • Active control of current by regenerative braking ratio adjustment is proposed. • More energy is recovered with smaller battery temperature rise. - Abstract: Battery thermal management is important for the safety and reliability of electric vehicle. Based on the parameters obtained from battery hybrid pulse power characterization test, a two-degree-of-freedom lumped thermal model is established. The battery model is then integrated with vehicle driving model to simulate real-time battery thermal responses. An active control method is proposed to reduce heat generation due to regenerative braking. The proposed control method not only subjects to the braking safety regulation, but also adjusts the regenerative braking ratio through a fuzzy controller. By comparing with other regenerative braking scenarios, the effectiveness of the proposed strategy has been validated. According to the results, the proposed control strategy suppresses battery temperature rise by modifying the charge current due to regenerative braking. The overlarge components of current are filtered out whereas the small ones are magnified. Therefore, with smaller battery temperature rise, more energy is recovered. Compared to the traditional passive heat dissipating, the proposed active methodology is feasible and provides a novel solution for electric vehicle battery thermal management.

  14. Adaptive regenerative braking for electric vehicles with an electric motor at the front axle using the state dependent Riccati equation control technique

    NARCIS (Netherlands)

    Jansen, S.; Alirezaei, M.; Kanarachos, S.

    2014-01-01

    In this paper a novel adaptive regenerative braking control concept for electric vehicles with an electric motor at the front axle is presented. It is well known that the "phased" type regenerative braking systems of category B maximize the amount of regenerative energy during braking. However,

  15. 49 CFR 393.52 - Brake performance.

    Science.gov (United States)

    2010-10-01

    ...: Type of motor vehicle Service brake systems Braking force as a percentage of gross vehicle or... specifications for performance-based brake testers for commercial motor vehicles, where braking force is the sum of the braking force at each wheel of the vehicle or vehicle combination as a percentage of gross...

  16. Energy-Regenerative Braking Control of Electric Vehicles Using Three-Phase Brushless Direct-Current Motors

    Directory of Open Access Journals (Sweden)

    Bo Long

    2013-12-01

    Full Text Available Regenerative braking provides an effective way of extending the driving range of battery powered electric vehicles (EVs. This paper analyzes the equivalent power circuit and operation principles of an EV using regenerative braking control technology. During the braking period, the switching sequence of the power converter is controlled to inverse the output torque of the three-phase brushless direct-current (DC motor, so that the braking energy can be returned to the battery. Compared with the presented methods, this technology can achieve several goals: energy recovery, electric braking, ultra-quiet braking and extending the driving range. Merits and drawbacks of different braking control strategy are further elaborated. State-space model of the EVs under energy-regenerative braking operation is established, considering that parameter variations are unavoidable due to temperature change, measured error, un-modeled dynamics, external disturbance and time-varying system parameters, a sliding mode robust controller (SMRC is designed and implemented. Phase current and DC-link voltage are selected as the state variables, respectively. The corresponding control law is also provided. The proposed control scheme is compared with a conventional proportional-integral (PI controller. A laboratory EV for experiment is setup to verify the proposed scheme. Experimental results show that the drive range of EVs can be improved about 17% using the proposed controller with energy-regeneration control.

  17. A study of novel regenerative braking system based on supercapacitor for electric vehicle driven by in-wheel motors

    Directory of Open Access Journals (Sweden)

    Li-qiang Jin

    2015-03-01

    Full Text Available Taking supercapacitor and battery pack as the energy storage unit, a novel type of regenerative braking system for electric vehicle driven by in-wheel motors is presented, and a braking energy regeneration control strategy is set up. Then, a co-simulation test based on CRUISE and Simulink is conducted. The results of simulation show that the novel type of system can ensure the safety of battery pack and significantly improve the rate of energy regeneration.

  18. Reconstruction of braking force in vehicles with electromechanically actuated wheel brakes; Rekonstruktion der Bremskraft bei Fahrzeugen mit elektromechanisch betaetigten Radbremsen

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, R.

    1999-07-01

    Modern braking systems have a variety of functions, but implementation of the enhanced functionality with conventional hydraulic systems is difficult because of electronic actuation. The car industry therefore is working on new braking systems in which the braking force is generated individually on the wheels by means of electromechanical actuators. Owing to their nonlinear characteristics and variable braking efficiency, electromechanically actuated wheel brakes must be operated in a closed control loop. The author presents a low-cost method for reconstruction of the braking force which is required for efficient control. [German] Aufgrund des gestiegenen Sicherheits- und Komfortbewusstseins der Fahrzeugkaeufer ist die Funktionsvielfalt moderner Bremssysteme in den letzten Jahren staendig gewachsen. Die Umsetzung der erweiterten Funktionalitaet mittels konventioneller Bremsenhydraulik ist jedoch durch den elektronischen Eingriff sehr aufwendig. - Von der Automobilzulieferindustrie werden daher neuartige Bremssysteme entwickelt, bei denen die Bremskraft an den einzelnen Raedern von elektromechanischen Bremsaktuatoren aufgebracht wird. - Elektromechanisch betaetigte Radbremsen muessen aufgrund ihres nichtlinearen Verhaltens und des veraenderlichen Wirkungsgrades im geschlossenen Regelkreis betrieben werden. In dieser Arbeit wird erstmals ein Verfahren vorgestellt, mit dem die fuer die Regelung benoetigte Rueckfuehrungsgroesse Bremskraft kostenguenstig rekonstruiert werden kann. (orig.)

  19. Evaluation of brake parameters in copper discs of various thicknesses and speeds using Neodymium – Iron – Boron Magnets

    Directory of Open Access Journals (Sweden)

    Anantha Krishna G. L.

    2018-01-01

    Full Text Available Neodymium – Iron – Boron (NdFeB permanent magnets of 12.5 mm thickness and 50 mm diameter are chosen for analyses because of their higher remanence and coercivity. Experimental analyses were carried out with Copper discs of thickness 4 mm, 6 mm and 8 mm at 2000 rpm, 3000 rpm, 4000 rpm and 5000 rpm. Experiments were conducted with three different positions of magnets such as 2 coaxial magnets, single magnet and single magnet with sudden application conditions. The brake parameters recorded are % speed reduction, deceleration and time taken. In 2 coaxial magnets condition, brake parameters are better in 6 mm thick disc. In single magnet condition, the brake parameters in 6 mm thick disc are found to be more consistent than 4 mm and 8 mm thick discs. In single magnet with sudden application condition, in 4 mm thick disc, the brake parameters are found better. During analysis, very high repulsion was experienced by magnet with 8 mm thick Copper disc at all the above mentioned speeds in single magnet with sudden application condition. For high speed train applications, single magnet condition with 6mm thick disc may be suitable. For high speed automotive applications, single magnet with sudden application condition with 4 mm thick disc may be suitable.

  20. Investigations on the braking safety of utility vehicles with retarders; Untersuchungen zur Bremssicherheit von Nutzfahrzeugen mit Retardern

    Energy Technology Data Exchange (ETDEWEB)

    Pittius, R.

    1996-12-31

    When the use of retarders in utility vehicles increased in the middle of the 80s, the Forschungsvereinigung Automobiltechnik (FAT) commissioned a study on the safety aspect of this braking technology in trucks. Retarders are wear-free permanent brakes that are fitted in the drive transmission system of utility vehicles, thereby generating braking forces only at the wheels of the live shaft. The question of the possible overbraking of the live shafts was just as well investigated as the interaction between the retarder and service brake in so-called integrated braking systems, and both under conditions of low adhesion as well as in the border area of the dynamics of vehicle movement. This subject met with considerable joint interest on the part of the motor vehicle industry as well as of manufacturers of towed vehicles and unit sets. FAT, therefore, commissioned the Institut fuer Kraftfahrwesen of the University of Hannover to carry out a three-phase research project on the braking behaviour and dynamics of vehicle movement of two-axle, single vehicles as well as of two- and three-part trailer trains equipped with retarders. (orig.) [Deutsch] Als Mitte der 80er Jahre der Einsatz von Retardern in Nutzfahrzeugen zunahm, hat die Forschungsvereinigung Automobiltechnik e.V. (FAT) den Sicherheitsaspekt dieser Bremstechnik im Lastzug untersuchen lassen. Retarder sind verschleissfreie Dauerbremsen, die im Triebstrang von Nutzfahrzeugen eingebaut werden und somit Bremskraefte nur an den Raedern der Antriebsachsen erzeugen. Die Frage einer moeglichen Ueberbremsung der Antriebsachsen sollte ebenso untersucht werden wie die Wechselwirkungen zwischen Retarder und Betriebsbremsanlage in sogenannten integrierten Bremssystemen, und zwar sowohl bei niedrigen Kraftschlussbdingungen als auch im fahrdynamischen Grenzbereich. An dieser Thematik bestand ein erhebliches gemeinsames Interesse der Motorwagenindustrie sowie der Anhaenger- und Aggregathersteller. Die FAT hat deshalb das

  1. Canadian high speed magnetically levitated vehicle system

    Energy Technology Data Exchange (ETDEWEB)

    Atherton, D L [Queen' s Univ., Kingston, Ont.; Belanger, P R; Burke, P E; Dawson, G E; Eastham, A R; Hayes, W F; Ooi, B T; Silvester, P; Slemon, G R

    1978-04-01

    A technically feasible high speed (400 to 480 km/h) guided ground transportation system, based on the use of the vehicle-borne superconducting magnets for electrodynamic suspension and guidance and for linear synchronous motor propulsion was defined as a future modal option for Canadian application. Analysis and design proposals were validated by large-scale tests on a rotating wheel facility and by modelling system components and their interactions. Thirty ton vehicles carrying 100 passengers operate over a flat-topped elevated guideway, which minimizes system down-time due to ice and snow accumulation and facilitates the design of turn-outs. A clearance of up to 15 cm is produced by the electrodynamic interaction between the vehicle-borne superconducting magnets and aluminum guideway strips. Propulsion and automatic system control is provided by the superconducting linear synchronous motor which operates at good efficiency (0.74) and high power factor (0.95). The vehicle is guided primarily by the interaction between the LSM field magnet array and flat null-flux loops overlying the stator windings in the guideway. The linear synchronous motor, electrodynamic suspension as well as levitation strip joints, parasitic LSM winding losses and limitations to the use of ferromagnetic guideway reinforcement were investigated experimentally on the test wheel facility. The use of a secondary suspension assures adequate dynamic stability, and good ride quality is achieved by optimized passive components with respect to lateral modes and by an actively controlled secondary suspension with respect to vertical motion.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Zutao Zhang

    2016-02-01

    Full Text Available 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.

  4. NASA diagonal-braked test vehicle evaluation of traction characteristics of grooved and ungrooved runway surfaces at Miami International Airport, Miami, Florida, 8-9 May 1973

    Science.gov (United States)

    Horne, W. B.

    1977-01-01

    Two runways were evaluated under artificially wetted conditions with the NASA diagonal-braked vehicle (DBV). Results of the evaluation which included a pavement drainage analysis, a pavement skid resistance analysis, and a DBV wet/dry stopping distance ratio analysis indicated that the ungrooved runway surfaces had poor water drainage characteristics and poor skid resistance under wet conditions at high speeds especially in rubbercoated areas of the runways. Grooving runways to a transverse 1-1/4 x 1/4 x 1/4 inch pattern greatly improved both the water drainage and pavement skid resistance capability of these asphaltic concrete surfaces.

  5. Airborne exposures associated with the typical use of an aerosol brake cleaner during vehicle repair work.

    Science.gov (United States)

    Fries, Michael; Williams, Pamela R D; Ovesen, Jerald; Maier, Andrew

    2018-04-19

    Many petroleum-based products are used for degreasing and cleaning purposes during vehicle maintenance and repairs. Although prior studies have evaluated chemical exposures associated with this type of work, most of these have focused on gasoline and exhaust emissions, with few samples collected solely during the use of an aerosol cleaning product. In this case study, we assess the type of airborne exposures that would be expected from the typical use of an aerosol brake cleaner during vehicle repair work. Eight exposure scenarios were evaluated over a two-day study in which the benzene content of the brake cleaner and potential for dilution ventilation and air flow varied. Both short-term (15 min) and task-based (≥1 hr) charcoal tube samples were collected in the breathing zone and adjacent work area and analyzed for total hydrocarbons (THCs), toluene, and benzene. The majority of personal (N = 48) and area (N = 47) samples had detectable levels of THC and toluene, but no detections of benzene were found. For the personal short-term samples, average airborne concentrations ranged from 3.1 - 61.5 ppm (13.8-217.5 mg/m 3 ) for THC and 2.2 - 44.0 ppm (8.2-162.5 mg/m 3 ) for toluene, depending on the scenario. Compared to the personal short-term samples, average concentrations were generally 2 to 3 times lower for the personal task-based samples and 2 to 5 times lower for the area short-term samples. The highest exposures occurred when the garage bay doors were closed, floor fan was turned off, or greatest amount of brake cleaner was used. These findings add to the limited dataset on this topic and can be used to bound or approximate worker or consumer exposures from use of aerosol cleaning products with similar compositions and use patterns.

  6. Control allocation for for regenerative braking of electric vehicles with an electric motor at the front axle using the state-dependent Riccati equation control technique

    NARCIS (Netherlands)

    Kanarachos, S.A.; Alirezaei, M.; Jansen, S.T.H.; Maurice, J.P.

    2014-01-01

    In this paper the systematic development of an integrated braking controller for a vehicle driven by an electric motor on the front axle is presented. The objective is to engage the electric motor only during braking, up to the point at which the vehicle reaches its manoeuvrability and stability

  7. Antisideslip and Antirollover Safety Speed Controller Design for Vehicle on Curved Road

    Directory of Open Access Journals (Sweden)

    Guo Lie

    2014-01-01

    Full Text Available When the drivers cannot be aware of the existing of forthcoming curved roads and fail to regulate their safety speeds accordingly, sideslip or rollover may occur with high probability. The antisideslip and antirollover control of vehicle on curved road in automatic highway systems is studied. The safety speed warning system is set before entering the curved road firstly. The speed adhesion control is adopted to shorten the braking distance while decelerating and to guarantee the safety speed. The velocity controller when decelerating on the straight path and the posture controller when driving on curved road are designed, respectively, utilizing integral backstepping technology. Simulation results demonstrate that this control system is characterized by quick and precise tracking and global stability. Consequently, it is able to avoid the dangerous operating conditions, such as sideslip and rollover, and guarantee the safety and directional stability when driving on curved road.

  8. A study on properties of a cone-type brake for motor vehicle winch

    Directory of Open Access Journals (Sweden)

    Dongxu Li

    2016-05-01

    Full Text Available The brake of winch is to prevent the occurrence of reverse slipping at working time. Based on the analysis of two types of brake, this article establishes the relationship model of the brake force and the angle of the screw thread on the brake shaft and builds the model of the relationship of the brake force and the height of the cone and found that the brake force is the largest when the angle of the screw is 45°. Also found that the brake force increases with the increase in the load, and the brake force is positively related to the height of the cone. Two brake mechanisms are manufactured and arranged in the same winch to conduct the experimental performance comparison. The experimental results show that the temperature of the winch with cone brake finally reaches about 60°C, which is 33% lower than the 90°C of the disk brake, and the no-load current of the cone brake winch is under 60 A, while in the disk brake winch it is over 90 A after 7 min, which consumes 33% energy than cone brake. The cone brake can reduce the occurrence of harmful friction and enhance the efficiency of winch and is able to solve the winch safety problem caused by nylon cable damage because of the heat accumulation.

  9. Practical Use of the Braking Attributes Measurements Results

    Directory of Open Access Journals (Sweden)

    Ondruš Ján

    2017-01-01

    Full Text Available This contribution deals with issues of braking the passenger car. The measurement of braking deceleration of the vehicle Kia Cee´d 1,6 16 V was carried out by an optical device Correvit system. The measurement was carried out on the airport of the village of Rosina located close to Zilina. 10 drivers of different age, praxis, and kilometers driven participated in the measurement. The measured process was the vehicle full braking with the service brake of the initial speed of approximately 50 km.h-1. Each of the drivers had 10 attempts. In the closure of this contribution the results of the performed measurements, their evaluation and comparison are presented. Practical result from the contribution is mainly the measurement set of braking deceleration of the respective vehicle during intensive braking.

  10. Fibre-reinforced ceramics for vehicle brakes; Faserverstaerkte Keramiken fuer Bremsenanwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Krenkel, W. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Stuttgart (Germany). Inst. fuer Bauweisen- und Konstruktionsforschung

    2000-07-01

    In the context of their aerospace research activities, DLR (Deutsches Zentrum fuer Luft- und Raumfahrt) developed a new process for producing ceramic fibre composite materials that are extremely light and tough. Apart from their applications in aerospace engineering, they have great potential for motor brakes with improved friction and wear characteristics. Excellent results were achieved with the new materials even with conventional brake liners. With customised liners, brake life may be prolonged to match the car life. Further applications are expected in trucks for transport in hazardous materials, high-speed trains, aircraft, industrial machinery and plants, and conveyor systems. [German] Im Rahmen der Raumfahrt-Forschung wurde vom Deutschen Zentrum fuer Luft- und Raumfahrt (DLR) das Fluessigsilicier-Verfahren zur Herstellung von keramischen Verbundwerkstoffen entwickelt. Diese extrem leichten und bruchzaehen Faserkeramiken haben sich unter den besonderen Bedingungen des Weltraums beispielsweise fuer Hitzeschutzstrukturen von Raumfahrzeugen hervorragend bewaehrt. Darueber hinaus zeigten Untersuchungen ein hohes Anwendungspotenzial fuer neue Bremsen mit deutlich verbesserten Reibungs- und Verschleisseigenschaften. Weiterentwicklungen des keramischen Gefueges fuehrten zu innovativen Leichtbau- bzw. Hochleistungs-Bremsen auf der Basis dieser harten und hitzebestaendigen Verbundwerkstoffe. Bereits mit serienmaessigen Bremsbelaegen wurden die heute geltenden Verschleiss- und Reibwertanforderungen teilweise weit uebertroffen. Die Leistungsfaehigkeit heutiger Bremssysteme kann damit deutlich gesteigert und die ungefederte Masse des Fahrwerks drastisch reduziert werden. Mit der zielgerichteten Anpassung geeigneter Belaege auf die neuen Keramik-Bremsscheiben scheint erstmals ein Einsatz von Lebensdauerbremsen moeglich zu sein, deren geringe Verschleissraten einen Austausch der Bremsscheiben waehrend der Betriebszeit eines Fahrzeugs ueberfluessig machen. Neben der

  11. Shuttle Rudder/Speed Brake Power Drive Unit (PDU) Gear Scuffing Tests With Flight Gears

    Science.gov (United States)

    Proctor, Margaret P.; Oswald, Fred B.; Krants, Timothy L.

    2005-01-01

    Scuffing-like damage has been found on the tooth surfaces of gears 5 and 6 of the NASA space shuttle rudder/speed brake power drive unit (PDU) number 2 after the occurrence of a transient back-driving event in flight. Tests were conducted using a pair of unused spare flight gears in a bench test at operating conditions up to 2866 rpm and 1144 in.-lb at the input ring gear and 14,000 rpm and 234 in.-lb at the output pinion gear, corresponding to a power level of 52 hp. This test condition exceeds the maximum estimated conditions expected in a backdriving event thought to produce the scuffing damage. Some wear marks were produced, but they were much less severe than the scuffing damaged produced during shuttle flight. Failure to produce scuff damage like that found on the shuttle may be due to geometrical variations between the scuffed gears and the gears tested herein, more severe operating conditions during the flight that produced the scuff than estimated, the order of the test procedures, the use of new hydraulic oil, differences between the dynamic response of the flight gearbox and the bench-test gearbox, or a combination of these. This report documents the test gears, apparatus, and procedures, summarizes the test results, and includes a discussion of the findings, conclusions, and recommendations.

  12. Independent Orbiter Assessment (IOA): Assessment of the rudder/speed brake subsystem FMEA/CIL

    Science.gov (United States)

    Wilson, R. E.

    1988-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Rudder/Speed Brake (RSB) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline along with the proposed Post 51-L CIL updates included. A resolution of each discrepancy from the comparison was provided through additional analysis as required. This report documents the results of that comparison for the Orbiter RSB hardware. The IOA product for the RSB analysis consisted of 38 failure mode worksheets that resulted in 27 potential critical items being identified. Comparison was made to the NASA baseline which consisted of 34 FMEAs and 18 CIL items. This comparison produced agreement on all CIL items. Based on the Pre 51-L baseline, all non-CIL FMEAs were also in agreement.

  13. Modeling the Turning Speed and Car Following Behaviors of Autonomous Vehicles in a Virtual World

    Directory of Open Access Journals (Sweden)

    Carrillo-González José Gerardo

    2015-07-01

    Full Text Available This article deals with mathematical models for controlling vehicles behavior in a virtual world, where two behaviors are considered: 1 curve turning and 2 car following situations, in this last is essential to provide a safety distance between the leader and the follower and at the same time keep the follower not delayed with respect to the leader, and in a curve turning the complexity is to provide a safety speed inside the curve and keep the car inside the lane. Using basic information as vehicles position, mathematical models can be developed for explaining the heading angle and the autonomous vehicles speed on curves, i.e. the controlled by the models. A model that predicts the autonomous vehicle speed on curves is developed considering previous data in other curves. Two models that control the acceleration/deceleration behavior of autonomous vehicles in a car following situation are proposed. In the first model, the parameters are calibrated with a proposed algorithm which enables accuracy in order to imitate the human behavior for accelerating and braking, and the second model provides a safety distance between the follower and the leader at sudden stops of the latter and employs the acceleration/deceleration top capabilities to follow the leader car similar to the human behavior.

  14. CONTROLLING THE SPEED OF ROLLING CUTS IN CONDITIONS OF REDUCTION OF BRAKE POWER OF CAR RETARDERS

    Directory of Open Access Journals (Sweden)

    D. M. Kozachenko

    2016-06-01

    Full Text Available Purpose. The study aims to develop the requirements for organization of the marshalling process in the conditions when the power of retarder positions is less than the nominal one. Methodology. The research is carried out using the train traffic safety theory and mathematical modelling of hump processes. Findings. The current technical standard documents regulating the operational performance of humps do not contain direct instructions on how to proceed in the event of brake power loss by car retarders, thus creating threats to the traffic safety. This problem is quite acute for the Ukrainian railways in connection with a chronic shortage of funds for the repair and renewal of technical equipment, including the humps. At the same time, a significant drop in the volume of work leads to the fact that the hump required processing capacity can be provided in case of partial failure of retarders as well. Herewith the most important task is to ensure the breaking-up safety in conditions of parametric failures of retarders. The analysis of dangerous situations, the occurrence of which is possible at humps, as well as the modelling of cut rolling, allowed establishing the connection between the value of retarder tire pressing force on the car wheels and the breaking-up modes, providing the safety of marshalling process. The paper sets the application areas of such measures as the breaking-up speed reduction, breaking-up termination, the use of additional braking by block hangers. Originality. The originality of the work lies in the fact that it first obtained the complex of dependencies that determine the performance requirements for the power of hump retarders and allow the staff to enter the appropriate limits for breaking-up modes to ensure the marshalling process safety. Practical value. The results of the research can be used to supplement the «Instruction on the maintenance of facilities of mechanized and automated humps» in order to determine

  15. Raising the speed limit from 75 to 80mph on Utah rural interstates: Effects on vehicle speeds and speed variance.

    Science.gov (United States)

    Hu, Wen

    2017-06-01

    In November 2010 and October 2013, Utah increased speed limits on sections of rural interstates from 75 to 80mph. Effects on vehicle speeds and speed variance were examined. Speeds were measured in May 2010 and May 2014 within the new 80mph zones, and at a nearby spillover site and at more distant control sites where speed limits remained 75mph. Log-linear regression models estimated percentage changes in speed variance and mean speeds for passenger vehicles and large trucks associated with the speed limit increase. Logistic regression models estimated effects on the probability of passenger vehicles exceeding 80, 85, or 90mph and large trucks exceeding 80mph. Within the 80mph zones and at the spillover location in 2014, mean passenger vehicle speeds were significantly higher (4.1% and 3.5%, respectively), as were the probabilities that passenger vehicles exceeded 80mph (122.3% and 88.5%, respectively), than would have been expected without the speed limit increase. Probabilities that passenger vehicles exceeded 85 and 90mph were non-significantly higher than expected within the 80mph zones. For large trucks, the mean speed and probability of exceeding 80mph were higher than expected within the 80mph zones. Only the increase in mean speed was significant. Raising the speed limit was associated with non-significant increases in speed variance. The study adds to the wealth of evidence that increasing speed limits leads to higher travel speeds and an increased probability of exceeding the new speed limit. Results moreover contradict the claim that increasing speed limits reduces speed variance. Although the estimated increases in mean vehicle speeds may appear modest, prior research suggests such increases would be associated with substantial increases in fatal or injury crashes. This should be considered by lawmakers considering increasing speed limits. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

  16. THE MOMENT OF UNSAFETY FOR DRIVING IN CONDITIONS OF POOR VISIBILITY TAKING INTO ACCOUNT THE EVALUATION OF VEHICLE BRAKING EFFICIENCY

    Directory of Open Access Journals (Sweden)

    A. Sarayev

    2014-02-01

    Full Text Available This study is aimed at investigation of a car collision with a pedestrian under limited visibility condi-tions. For this purpose an expert has to analyze the accident details and determine the critical time at which the car driver must take an action to avoid the collision. The analysis is complicated due to the fact that the vehicle is equipped with an anti-blocking braking system and does not leave a braking trace on the pavement. In this case, a relevant expert analysis technique does not exist. The development of such techniques as the basis of this scientific work is given.

  17. A unique concept for automatically controlling the braking action of wheeled vehicles during minimum distance stops

    Science.gov (United States)

    Barthlome, D. E.

    1975-01-01

    Test results of a unique automatic brake control system are outlined and a comparison is made of its mode of operation to that of an existing skid control system. The purpose of the test system is to provide automatic control of braking action such that hydraulic brake pressure is maintained at a near constant, optimum value during minimum distance stops.

  18. Energy Management and Control of Electric Vehicles, Using Hybrid Power Source in Regenerative Braking Operation

    Directory of Open Access Journals (Sweden)

    Bo Long

    2014-07-01

    Full Text Available Today’s battery powered electric vehicles still face many issues: (1 Ways of improving the regenerative braking energy; (2 how to maximally extend the driving-range of electric vehicles (EVs and prolong the service life of batteries; (3 how to satisfy the energy requirements of the EVs both in steady and dynamic state. The electrochemical double-layer capacitors, also called ultra-capacitors (UCs, have the merits of high energy density and instantaneous power output capability, and are usually combined with power battery packs to form a hybrid power supply system (HPSS. The power circuit topology of the HPSS has been illustrated in this paper. In the proposed HPSS, all the UCs are in series, which may cause an imbalanced voltage distribution of each unit, moreover, the energy allocation between the batteries and UCs should also be considered. An energy-management scheme to solve this problem has been presented. Moreover, due to the parameter variations caused by temperature changes and produced errors, the modelling procedure of the HPSS becomes very difficult, so an H∞ current controller is presented. The proposed hybrid power source circuit is implemented on a laboratory hardware setup using a digital signal processor (DSP. Simulation and experimental results have been put forward to demonstrate the feasibility and validity of the approach.

  19. Experimental investigation of an accelerometer controlled automatic braking system

    Science.gov (United States)

    Dreher, R. C.; Sleeper, R. K.; Nayadley, J. R., Sr.

    1972-01-01

    An investigation was made to determine the feasibility of an automatic braking system for arresting the motion of an airplane by sensing and controlling braked wheel decelerations. The system was tested on a rotating drum dynamometer by using an automotive tire, wheel, and disk-brake assembly under conditions which included two tire loadings, wet and dry surfaces, and a range of ground speeds up to 70 knots. The controlling parameters were the rates at which brake pressure was applied and released and the Command Deceleration Level which governed the wheel deceleration by controlling the brake operation. Limited tests were also made with the automatic braking system installed on a ground vehicle in an effort to provide a more realistic proof of its feasibility. The results of this investigation indicate that a braking system which utilizes wheel decelerations as the control variable to restrict tire slip is feasible and capable of adapting to rapidly changing surface conditions.

  20. Development of nondestructive system for detecting the cracks in KTX brake disk using Rayleigh wave

    International Nuclear Information System (INIS)

    Kim, Min Soo; Lee, Ho Yong; Yeom, Yun Taek; Park, Jin Hyun; Song, Sung Jing; Kim, Hak Joon; Kwon, Sung Duck

    2017-01-01

    Recently, KTX (Korean Train Express) train stoppage accidents were mainly caused by malfunctioning equipment, aging and cracking of railway vehicles, crack breakages of brake disks, and breakages of brake disks. Breakage of brake disk can cause large-scale casualties such as high-speed collision and concern about derailment by hitting lower axle and wheel. Therefore, in this study, a brake disk with solid and ventilation type, which is the brake disk of a KTX train was modeled, and a dynamometer system was constructed to operate the disk. A Rayleigh wave was used to inspect the surface of the brake disk. An ultrasonic inspection module was developed for the brake disk by using a local immersion method due to the difficulty involved in ultrasonic inspection using an existing immersion method. In addition, the surface defects of the brake disk were evaluated using a dynamometer mock-up system and an ultrasonic inspection module of the brake disk

  1. Development of nondestructive system for detecting the cracks in KTX brake disk using Rayleigh wave

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Soo; Lee, Ho Yong [Korea Railroad Research Institute, Uiwang (Korea, Republic of); Yeom, Yun Taek; Park, Jin Hyun; Song, Sung Jing; Kim, Hak Joon [Dept. of Mechanical Engineering, Sungkyunkwan University, Suwon (Korea, Republic of); Kwon, Sung Duck [Dept. of Physics, Andong National University, Andong (Korea, Republic of)

    2017-02-15

    Recently, KTX (Korean Train Express) train stoppage accidents were mainly caused by malfunctioning equipment, aging and cracking of railway vehicles, crack breakages of brake disks, and breakages of brake disks. Breakage of brake disk can cause large-scale casualties such as high-speed collision and concern about derailment by hitting lower axle and wheel. Therefore, in this study, a brake disk with solid and ventilation type, which is the brake disk of a KTX train was modeled, and a dynamometer system was constructed to operate the disk. A Rayleigh wave was used to inspect the surface of the brake disk. An ultrasonic inspection module was developed for the brake disk by using a local immersion method due to the difficulty involved in ultrasonic inspection using an existing immersion method. In addition, the surface defects of the brake disk were evaluated using a dynamometer mock-up system and an ultrasonic inspection module of the brake disk.

  2. The Application of Vibration Accelerations in the Assessment of Average Friction Coefficient of a Railway Brake Disc

    Directory of Open Access Journals (Sweden)

    Sawczuk Wojciech

    2017-06-01

    Full Text Available Due to their wide range of friction characteristics resulting from the application of different friction materials and good heat dissipation conditions, railway disc brakes have long replaced block brakes in many rail vehicles. A block brake still remains in use, however, in low speed cargo trains. The paper presents the assessment of the braking process through the analysis of vibrations generated by the components of the brake system during braking. It presents a possibility of a wider application of vibroacoustic diagnostics (VA, which aside from the assessment of technical conditions (wear of brake pads also enables the determination of the changes of the average friction coefficient as a function of the braking onset speed. Vibration signals of XYZ were measured and analyzed. The analysis of the results has shown that there is a relation between the values of the point measures and the wear of the brake pads.

  3. An antilock molecular braking system.

    Science.gov (United States)

    Sun, Wei-Ting; Huang, Shou-Ling; Yao, Hsuan-Hsiao; Chen, I-Chia; Lin, Ying-Chih; Yang, Jye-Shane

    2012-08-17

    A light-driven molecular brake displaying an antilock function is constructed by introducing a nonradiative photoinduced electron transfer (PET) decay channel to compete with the trans (brake-off) → cis (brake-on) photoisomerization. A fast release of the brake can be achieved by deactivating the PET process through addition of protons. The cycle of irradiation-protonation-irradiation-deprotonation conducts the brake function and mimics the antilock braking system (ABS) of vehicles.

  4. Study on Differential Regenerative Braking Torque Control to Increase the Stability of the Small Electric Vehicle with Four In-Wheel Motors

    Directory of Open Access Journals (Sweden)

    Ali N. M.

    2017-01-01

    Full Text Available Based on the advantages of the electric motor such as fast and precise torque response, the performance of the electric vehicle (EV can be improved. During braking or driving on the cornering, the vehicle will over steer or under steer if a car turns by more or less than the amount commanded by the driver. To improve the stability of the small EV with four in-wheel motors, the differential regenerative braking torque control is proposed. In this system, the regenerative braking torque at each wheel will be controlled individually based on the value of slip ratio. If the slip ratio is greater than the optimum value, the regenerative brake will turn off. In this situation, the electric motor will not produce the regenerative braking torque. Conversely, if the slip ratio lower than the optimum value, the regenerative brake will turn on and the electric motor will generate the regenerative braking torque. In the numerical analysis, to investigate the effectiveness of the proposed model, the road condition is set to an icy road on the left tire and dry asphalt on the right tire. From the simulation results, the differential regenerative braking torque control can prevent the tire from lock-up and avoid the vehicle from skidding.

  5. Hydrostatically regenerative brake system for commercial vehicles and mobil hydraulic work engines; Hydrostatisch Regeneratives Bremssystem (HRB) fuer Nutzfahrzeuge und mobile Arbeitsmaschinen

    Energy Technology Data Exchange (ETDEWEB)

    Kliffken, Markus Gustav; Ehret, Christine; Stawiarksi, Robert [Bosch Rexroth AG, Elchingen (Germany)

    2008-07-01

    The characteristics of the hydraulic storage system and the hydrostatically renewable brake system of Bosch Rexroth AG (Eichingen, Federal Republic of Germany) as a hydraulic hybrid system permit a fast integration in the vehicle, low costs of maintenance and high security. The system is suitable for vehicles which frequently start and brake. As a function of the operating cycle, savings of up to 25 % are possible. Additionally, the hydrostatically renewable brake system reduces the wear of brakes and provides a larger travelling comfort by eliminating interruptions of traction power. At present, the functionality of the hydrostatically renewable brake system is tested in a field test at Berlin (Federal Republic of Germany). Further prototypes also are developed and tested in the U.S.A. up to the end of the year 2008.

  6. Regenerative braking failures in battery electric vehicles and their impact on the driver.

    Science.gov (United States)

    Cocron, Peter; Neumann, Isabel; Kreußlein, Maria; Wanner, Daniel; Bierbach, Maxim; Krems, Josef F

    2018-09-01

    A unique feature of battery electric vehicles (BEV) is their regenerative braking system (RBS) to recapture kinetic energy in deceleration maneuvers. If such a system is triggered via gas pedal, most deceleration maneuvers can be executed by just using this pedal. This impacts the driving task as different deceleration strategies can be applied. Previous research has indicated that a RBS failure leading to a sudden reduced deceleration represents an adverse event for BEV drivers. In the present study, we investigated such a failure's impact on the driver's evaluation and behavior. We conducted an experiment on a closed-off test track using a modified BEV that could temporarily switch off the RBS. One half of the 44 participants in the study received information about an upcoming RBS failure whereas the other half did not. While 91% of the drivers receiving prior information noticed the RBS failure, only 48% recognized it in the "uniformed" group. In general, the failure and the perception of its occurrence influenced the driver's evaluation and behavior more than receiving prior information. Nevertheless, under the tested conditions, drivers kept control and were able to compensate for the RBS failure. As the participants drove quite simple maneuvers in our experiment, further studies are needed to validate our findings using more complex driving settings. Given that RBS failures could have severe consequences, appropriate information and warning strategies for drivers are necessary. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Utilization of a hardware-in-the-loop-system for controlling the speed of an eddy current brake

    International Nuclear Information System (INIS)

    Kramer, V; Brauneis, P; Schmidt, K; Mishra, R

    2012-01-01

    Rapid prototyping with a hardware-in-the-loop (HiL) system significantly reduces the development time for controller-type testing and is widely used in various fields of engineering. In this discussion, a controller is developed for a speed control application utilizing a magnetic brake. A mathematical model is presented first that has been implemented in Matlab/ Simulink. The controller development steps are described that will form the basis of a control system for a wind turbine. A test is carried out that simulates the wind turbine inertial load.

  8. Development of hydraulic brake actuator for active brake control; Active brake seigyoyo yuatsu booster no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Y; Hattori, M. Sugisawa, M.; Nishii, M [Aisin Seiki Co. Ltd., Aichi (Japan)

    1997-10-01

    Recently, application of active brake control systems of the vehicle are increasing. (Vehicle stability control, Panic brake assist ) We have developed a new hydraulic brake actuator for active brake control systems. New hydraulic brake actuator is composed of the three parts. (Hydraulic booster unit, Power supply unit, Control valve unit) This report describes the construction of the new hydraulic booster unit. 2 refs., 10 figs.

  9. FEATURES OF RESOURCE TESTING OF THE HYDRAULIC BRAKE DRIVE ELEMENTS OF VEHICLES EQUIPPED WITH ABS

    Directory of Open Access Journals (Sweden)

    A. Revin

    2011-01-01

    Full Text Available The analysis of the resource testing facilities and methods of automobile brake cylinders in terms of ABS working process adequacy is carried out. A testing stand construction and a method of carrying out the resource testing of hydraulic drive elements of the automobile automated braking sys-tem is offered.

  10. Robust control of regenerative and hydraulic brakes for enhancing directional stability of an electric vehicle during straight-line braking

    NARCIS (Netherlands)

    Lv, Chen; Zhang, Junzhi; Li, Yutong; Zhao, Bolin; Yuan, Ye

    2016-01-01

    Thanks to the actuation flexibility of their systems, electric vehicles with individual powertrains, including in-wheel and on-board motors, are a very popular research topic amongst various types of electrified powertrain architectures. The introduction of the individual electric powertrain

  11. Capacitated Vehicle Routing with Nonuniform Speeds

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Molinaro, Marco; Nagarajan, Viswanath

    2016-01-01

    is the distance traveled divided by its speed.Our algorithm relies on a new approximate minimum spanning tree construction called Level-Prim, which is related to but different from Light Approximate Shortest-path Trees. We also extend the widely used tour-splitting technique to nonuniform speeds, using ideas from...

  12. Stability control for high speed tracked unmanned vehicles

    Science.gov (United States)

    Pape, Olivier; Morillon, Joel G.; Houbloup, Philippe; Leveque, Stephane; Fialaire, Cecile; Gauthier, Thierry; Ropars, Patrice

    2005-05-01

    The French Military Robotic Study Program (introduced in Aerosense 2003), sponsored by the French Defense Procurement Agency and managed by Thales as the prime contractor, focuses on about 15 robotic themes which can provide an immediate "operational add-on value". The paper details the "automatic speed adjustment" behavior (named SYR4), developed by Giat Industries Company, which main goal is to secure the teleoperated mobility of high speed tracked vehicles on rough grounds; more precisely, the validated low level behavior continuously adjusts the vehicle speed taking into account the teleperator wish AND the maximum speed that the vehicle can manage safely according to the commanded radius of curvature. The algorithm is based on a realistic physical model of the ground-tracks relation, taking into account many vehicle and ground parameters (such as ground adherence and dynamic specificities of tracked vehicles). It also deals with the teleoperator-machine interface, providing a balanced strategy between both extreme behaviors: a) maximum speed reduction before initiating the commanded curve; b) executing the minimum possible radius without decreasing the commanded speed. The paper presents the results got from the military acceptance tests performed on tracked SYRANO vehicle (French Operational Demonstrator).

  13. Scaling model for a speed-dependent vehicle noise spectrum

    Directory of Open Access Journals (Sweden)

    Giovanni Zambon

    2017-06-01

    Full Text Available Considering the well-known features of the noise emitted by moving sources, a number of vehicle characteristics such as speed, unladen mass, engine size, year of registration, power and fuel were recorded in a dedicated monitoring campaign performed in three different places, each characterized by different number of lanes and the presence of nearby reflective surfaces. A full database of 144 vehicles (cars was used to identify statistically relevant features. In order to compare the vehicle transit noise in different environmental condition, all 1/3-octave band spectra were normalized and analysed. Unsupervised clustering algorithms were employed to group together spectrum levels with similar profiles. Our results corroborate the well-known fact that speed is the most relevant characteristic to discriminate between different vehicle noise spectrum. In keeping with this fact, we present a new approach to predict analytically noise spectra for a given vehicle speed. A set of speed-dependent analytical functions are suggested in order to fit the normalized average spectrum profile at different speeds. This approach can be useful for predicting vehicle speed based purely on its noise spectrum pattern. The present work is complementary to the accurate analysis of noise sources based on the beamforming technique.

  14. Low Speed Longitudinal Control Algorithms for Automated Vehicles in Simulation and Real Platforms

    Directory of Open Access Journals (Sweden)

    Mauricio Marcano

    2018-01-01

    Full Text Available Advanced Driver Assistance Systems (ADAS acting over throttle and brake are already available in level 2 automated vehicles. In order to increase the level of automation new systems need to be tested in an extensive set of complex scenarios, ensuring safety under all circumstances. Validation of these systems using real vehicles presents important drawbacks: the time needed to drive millions of kilometers, the risk associated with some situations, and the high cost involved. Simulation platforms emerge as a feasible solution. Therefore, robust and reliable virtual environments to test automated driving maneuvers and control techniques are needed. In that sense, this paper presents a use case where three longitudinal low speed control techniques are designed, tuned, and validated using an in-house simulation framework and later applied in a real vehicle. Control algorithms include a classical PID, an adaptive network fuzzy inference system (ANFIS, and a Model Predictive Control (MPC. The simulated dynamics are calculated using a multibody vehicle model. In addition, longitudinal actuators of a Renault Twizy are characterized through empirical tests. A comparative analysis of results between simulated and real platform shows the effectiveness of the proposed framework for designing and validating longitudinal controllers for real automated vehicles.

  15. In pedestrian crashes, it's vehicle speed that matters the most

    Science.gov (United States)

    2000-05-13

    A recently prepared report on pedestrian injuries provides these two main findings: 1) regardless of age, pedestrians involved in crashes are more likely to be killed as vehicle speeds increase; and 2) in crashes at any speed, older pedestrians are m...

  16. Investigation into the Use of Water Based Brake Fluid for Light Loads

    Directory of Open Access Journals (Sweden)

    W. A. Akpan

    2012-12-01

    Full Text Available This paper addresses the possibility of using water based fluid as a brake fluid for light loads. Characterization of both standard and water based braked fluids formulated was carried out. The properties of the latter were compared with that of a standard commercial brake fluid. The actual test of the formulated brake fluid was carried out with a Nissan Sunny vehicle model 1.5 within the speed range of 20km/hr to 80km/hr at the permanent campus of University of Uyo and the braking efficiency obtained attest to its suitability for light loads.

  17. ANALYSIS OF POSSIBILITY TO AVOID A RUNNING-DOW ACCIDENT TIMELY BRAKING

    Directory of Open Access Journals (Sweden)

    Sarayev, A.

    2013-06-01

    Full Text Available Such circumstances under which the drive can stop the vehicle by applying timely braking before reaching the pedestrian crossing or decrease the speed to the safe limit to avoid a running-down accident is considered.

  18. Exposure to asbestos during brake maintenance of automotive vehicles by different methods.

    Science.gov (United States)

    Kauppinen, T; Korhonen, K

    1987-05-01

    Asbestos concentrations were measured during the different operations of brake maintenance of passenger cars, trucks and buses in 24 Finnish workplaces. The estimated average asbestos exposure during the workday (8-hr time-weighted average) was 0.1-0.2 fibers/cm3 during brake repair of trucks or buses, and under 0.05 f/cm3 during repair of passenger car brakes when the background concentration was not included in the calculations. The background concentration was estimated to be less than 0.1 f/cm3. During brake maintenance of buses and trucks, heavy exposure, 0.3-125 (mean 56) f/cm3, was observed during machine grinding of new brake linings if local exhaust was not in use. Other short-term operations during which the concentration exceeded 1 f/cm3 were the cleaning of brakes with a brush, wet cloth or compressed air jet. During brake servicing of passenger cars, the concentration of asbestos exceeded 1 f/cm3 only during compressed air blowing without local exhaust. The different methods of decreasing the exposure and the risk of asbestos-related diseases among car mechanics are discussed.

  19. THE INFLUENCE OF BRAKE PADS THERMAL CONDUCTIVITY ON PASSANGER CAR BRAKE SYSTEM EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Predrag D Milenković

    2010-01-01

    Full Text Available In phase of vehicle braking system designing, besides of mechanical characteristics, it is also necessary to take under consideration the system's thermal features. This is because it is not enough just to achieve proper braking power, for the brake system to be effective but equally important thing is the dissipation of heat to the environment. Heat developed in the friction surfaces dissipate into the environment over the disk in one hand and through the brake linings and caliper, in the other. The striving is to make that greatest amount of heat to dissipate not threw the brake pads but threw disc. The experimental researching of heat transfer process taking place at vehicle brakes was made in the R&D Center of "Zastava automobili" car factory in order to increase the efficiency of brake system. The standard laboratory and road test procedures were used, according to factory quality regulations. The modern equipment such as thermo camera, thermo couples, torque transducers, signal amplifiers, optical speed measuring system and laptop computer were used. In this paper will be shown the part of the experimental researching, which refers to the thermal conductivity of brake pad friction linings.

  20. Hydrogen tube vehicle for supersonic transport: 2. Speed and energy

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Arnold R. [Vehicle Projects Inc and Supersonic Tubevehicle LLC, 200 Violet St, Suite 100, Golden, CO 80401 (United States)

    2010-06-15

    The central concept of a new idea in high-speed transport is that operation of a vehicle in a hydrogen atmosphere, because of the low density of hydrogen, would increase sonic speed by a factor of 3.8 and decrease drag by 15 relative to air. A hydrogen atmosphere requires that the vehicle operate within a hydrogen-filled tube or pipeline, which serves as a phase separator. The supersonic tube vehicle (STV) can be supersonic with respect to air outside the tube while remaining subsonic inside. It breathes hydrogen fuel for its propulsion fuel cells from the tube itself. This paper, second in a series on the scientific foundations of the supersonic tube vehicle, tests the hypothesis that the STV will be simultaneously fast and energy efficient by comparing its predicted speed and energy consumption with that of four long-haul passenger transport modes: road, rail, maglev, and air. The study establishes the speed ranking STV >> airplane > maglev > train > coach (intercity bus) and the normalized energy consumption ranking Airplane >> coach > maglev > train > STV. Consistent with the hypothesis, the concept vehicle is both the fastest and lowest energy consuming mode. In theory, the vehicle can cruise at Mach 2.8 while consuming less than half the energy per passenger of a Boeing 747 at a cruise speed of Mach 0.81. (author)

  1. Reduction Vehicle Speed Using GPS Android Smart Phone Programming

    Directory of Open Access Journals (Sweden)

    Sameer Sami Hassan

    2017-07-01

    Full Text Available Today the new generation of smart phone such as Samsung galaxy, Sony, Motorola, HTC is used to build smart applications that made the human life more comfortable and safe. The Android open source operating system with java programming language can be used to develop such applications. In this paper a new software application has been developed using Samsung, galaxy note smart phone to control the speed of vehicle using GPS and Android programming for such smart phone. By collecting the speed and location information from Global Position System (GPS receiver and using the global map application programming interface to determine the location nearby university, school and hospital in Baghdad city. The application will be check the speed of vehicle in zone of school, hospital and university using GPS information. If the speed over the limit the application produce sound alarm to reduce the speed to set up limit.

  2. Analysis of the dynamics of movement of the landing vehicle with an inflatable braking device on the final trajectory under the influence of wind load

    Science.gov (United States)

    Koryanov, V.; Kazakovtsev, V.; Harri, A.-M.; Heilimo, J.; Haukka, H.; Aleksashkin, S.

    2015-10-01

    This research work is devoted to analysis of angular motion of the landing vehicle (LV) with an inflatable braking device (IBD), taking into account the influence of the wind load on the final stage of the movement. Using methods to perform a calculation of parameters of angular motion of the landing vehicle with an inflatable braking device based on the availability of small asymmetries, which are capable of complex dynamic phenomena, analyzes motion of the landing vehicle at the final stage of motion in the atmosphere.

  3. Investigation into the use of water based brake fluid for light loads ...

    African Journals Online (AJOL)

    The actual test of the formulated brake fluid was carried out with a Nissan Sunny vehicle model 1.5 within the speed range of 20km/hr to 80km/hr at the permanent campus· of University of Uyo and the· braking effiqiency obtained at test to its suitability for light loads. Keywords·: Water-based, Brake fluid properties, Light loads ...

  4. Braking System Modeling and Brake Temperature Response to Repeated Cycle

    Directory of Open Access Journals (Sweden)

    Zaini Dalimus

    2014-12-01

    Full Text Available Braking safety is crucial while driving the passenger or commercial vehicles. Large amount of kinetic energy is absorbed by four brakes fitted in the vehicle. If the braking system fails to work, road accident could happen and may result in death. This research aims to model braking system together with vehicle in Matlab/Simulink software and measure actual brake temperature. First, brake characteristic and vehicle dynamic model were generated to estimate friction force and dissipated heat. Next, Arduino based prototype brake temperature monitoring was developed and tested on the road. From the experiment, it was found that brake temperature tends to increase steadily in long repeated deceleration and acceleration cycle.

  5. Braking Control for Improving Ride Comfort

    Directory of Open Access Journals (Sweden)

    Lee Jonghyup

    2018-01-01

    Full Text Available While many vehicle control systems focus on vehicle safety and vehicle performance at high speeds, most driving conditions are very low risk situations. In such a driving situation, the ride comfort of the vehicle is the most important performance index of the vehicle. Electro mechanical brake (EMB and other brake-by-wire (BBW systems have been actively researched. As a result, braking actuators in vehicles are more freely controllable, and research on improving ride comfort is also possible. In this study, we develop a control algorithm that dramatically improves ride comfort in low risk braking situations. A method for minimizing the inconvenience of a passenger due to a suddenly changing acceleration at the moment when the vehicle is stopped is presented. For this purpose, an acceleration trajectory is generated that minimizes the discomfort index defined by the change in acceleration, jerk. A controller is also designed to track this trajectory. The algorithm that updates the trajectory is designed considering the error due to the phase lag occurring in the controller and the plant. In order to verify the performance of this controller, simulation verification is completed using a car simulator, Carsim. As a result, it is confirmed that the ride comfort is dramatically improved.

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

    Science.gov (United States)

    Vadeby, Anna; Forsman, Åsa

    2017-06-01

    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

  7. Vehicle Speed Estimation and Forecasting Methods Based on Cellular Floating Vehicle Data

    Directory of Open Access Journals (Sweden)

    Wei-Kuang Lai

    2016-02-01

    Full Text Available Traffic information estimation and forecasting methods based on cellular floating vehicle data (CFVD are proposed to analyze the signals (e.g., handovers (HOs, call arrivals (CAs, normal location updates (NLUs and periodic location updates (PLUs from cellular networks. For traffic information estimation, analytic models are proposed to estimate the traffic flow in accordance with the amounts of HOs and NLUs and to estimate the traffic density in accordance with the amounts of CAs and PLUs. Then, the vehicle speeds can be estimated in accordance with the estimated traffic flows and estimated traffic densities. For vehicle speed forecasting, a back-propagation neural network algorithm is considered to predict the future vehicle speed in accordance with the current traffic information (i.e., the estimated vehicle speeds from CFVD. In the experimental environment, this study adopted the practical traffic information (i.e., traffic flow and vehicle speed from Taiwan Area National Freeway Bureau as the input characteristics of the traffic simulation program and referred to the mobile station (MS communication behaviors from Chunghwa Telecom to simulate the traffic information and communication records. The experimental results illustrated that the average accuracy of the vehicle speed forecasting method is 95.72%. Therefore, the proposed methods based on CFVD are suitable for an intelligent transportation system.

  8. Open tube guideway for high speed air cushioned vehicles

    Science.gov (United States)

    Goering, R. S. (Inventor)

    1974-01-01

    This invention is a tubular shaped guideway for high-speed air-cushioned supported vehicles. The tubular guideway is split and separated such that the sides of the guideway are open. The upper portion of the tubular guideway is supported above the lower portion by truss-like structural members. The lower portion of the tubular guideway may be supported by the terrain over which the vehicle travels, on pedestals or some similar structure.

  9. Vision based speed breaker detection for autonomous vehicle

    Science.gov (United States)

    C. S., Arvind; Mishra, Ritesh; Vishal, Kumar; Gundimeda, Venugopal

    2018-04-01

    In this paper, we are presenting a robust and real-time, vision-based approach to detect speed breaker in urban environments for autonomous vehicle. Our method is designed to detect the speed breaker using visual inputs obtained from a camera mounted on top of a vehicle. The method performs inverse perspective mapping to generate top view of the road and segment out region of interest based on difference of Gaussian and median filter images. Furthermore, the algorithm performs RANSAC line fitting to identify the possible speed breaker candidate region. This initial guessed region via RANSAC, is validated using support vector machine. Our algorithm can detect different categories of speed breakers on cement, asphalt and interlock roads at various conditions and have achieved a recall of 0.98.

  10. Regenerative Intelligent Brake Control for Electric Motorcycles

    Directory of Open Access Journals (Sweden)

    Juan Jesús Castillo Aguilar

    2017-10-01

    Full Text Available Vehicle models whose propulsion system is based on electric motors are increasing in number within the automobile industry. They will soon become a reliable alternative to vehicles with conventional propulsion systems. The main advantages of this type of vehicles are the non-emission of polluting gases and noise and the effectiveness of electric motors compared to combustion engines. Some of the disadvantages that electric vehicle manufacturers still have to solve are their low autonomy due to inefficient energy storage systems, vehicle cost, which is still too high, and reducing the recharging time. Current regenerative systems in motorcycles are designed with a low fixed maximum regeneration rate in order not to cause the rear wheel to slip when braking with the regenerative brake no matter what the road condition is. These types of systems do not make use of all the available regeneration power, since more importance is placed on safety when braking. An optimized regenerative braking strategy for two-wheeled vehicles is described is this work. This system is designed to recover the maximum energy in braking processes while maintaining the vehicle’s stability. In order to develop the previously described regenerative control, tyre forces, vehicle speed and road adhesion are obtained by means of an estimation algorithm. A based-on-fuzzy-logic algorithm is programmed to carry out an optimized control with this information. This system recuperates maximum braking power without compromising the rear wheel slip and safety. Simulations show that the system optimizes energy regeneration on every surface compared to a constant regeneration strategy.

  11. Magnetic suspension and guidance of high speed vehicles. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Alston, I A; Clark, J M; Hayden, J T

    1972-12-01

    Technical and economical assessments of magnetic suspensions for high speed vehicles and transport systems are reported. In these suspensions the suspending magnet takes the form of a powerful superconducting electromagnet that induces currents while it moves over conducting sheets or loops. A number of vehicle track designs are evaluated for operating cost effectiveness. It is shown that propulsion systems using power collected from the track are more expensive than those using power generated onboard the vehicle, and that the conducting sheet suspension is slightly more expensive than the null flux suspension.

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

    Science.gov (United States)

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

    2018-04-01

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

  13. On friction braking demand with regenerative braking

    NARCIS (Netherlands)

    Walker, A.M.; Lampérth, M.U.; Wilkins, S.

    2002-01-01

    Developments in Hybrid Electric and pure Electric Vehicles are intended to improve the operational efficiency of road vehicles. Regenerative braking, which has long been established in rail vehicles, is integral to efficiency improvement, with up to 30% of overall traction energy demand satisfied by

  14. Braking System for Wind Turbines

    Science.gov (United States)

    Krysiak, J. E.; Webb, F. E.

    1987-01-01

    Operating turbine stopped smoothly by fail-safe mechanism. Windturbine braking systems improved by system consisting of two large steel-alloy disks mounted on high-speed shaft of gear box, and brakepad assembly mounted on bracket fastened to top of gear box. Lever arms (with brake pads) actuated by spring-powered, pneumatic cylinders connected to these arms. Springs give specific spring-loading constant and exert predetermined load onto brake pads through lever arms. Pneumatic cylinders actuated positively to compress springs and disengage brake pads from disks. During power failure, brakes automatically lock onto disks, producing highly reliable, fail-safe stops. System doubles as stopping brake and "parking" brake.

  15. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Science.gov (United States)

    2010-10-01

    ... stock or natural rubber (NR). Chipping means a condition in which small pieces are missing from the... average decrease in hardness of seven of the eight cups tested (six wheel cylinder and one master cylinder... short piece of natural rubber, EPDM, SBR, or butyl tubing. (c) Place 60 ±1 ml. of brake fluid and the...

  16. Considering Variable Road Geometry in Adaptive Vehicle Speed Control

    Directory of Open Access Journals (Sweden)

    Xinping Yan

    2013-01-01

    Full Text Available Adaptive vehicle speed control is critical for developing Advanced Driver Assistance Systems (ADAS. Vehicle speed control considering variable road geometry has become a hotspot in ADAS research. In this paper, first, an exploration of intrinsic relationship between vehicle operation and road geometry is made. Secondly, a collaborative vehicle coupling model, a road geometry model, and an AVSC, which can respond to variable road geometry in advance, are developed. Then, based on H∞ control method and the minimum energy principle, a performance index is specified by a cost function for the proposed AVSC, which can explicitly consider variable road geometry in its optimization process. The proposed AVSC is designed by the Hamilton-Jacobi Inequality (HJI. Finally, simulations are carried out by combining the vehicle model with the road geometry model, in an aim of minimizing the performance index of the AVSC. Analyses of the simulation results indicate that the proposed AVSC can automatically and effectively regulate speed according to variable road geometry. It is believed that the proposed AVSC can be used to improve the economy, comfort, and safety effects of current ADAS.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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

  19. Vehicle Routing Problems with Fuel Consumption and Stochastic Travel Speeds

    Directory of Open Access Journals (Sweden)

    Yanling Feng

    2017-01-01

    Full Text Available Conventional vehicle routing problems (VRP always assume that the vehicle travel speed is fixed or time-dependent on arcs. However, due to the uncertainty of weather, traffic conditions, and other random factors, it is not appropriate to set travel speeds to fixed constants in advance. Consequently, we propose a mathematic model for calculating expected fuel consumption and fixed vehicle cost where average speed is assumed to obey normal distribution on each arc which is more realistic than the existing model. For small-scaled problems, we make a linear transformation and solve them by existing solver CPLEX, while, for large-scaled problems, an improved simulated annealing (ISA algorithm is constructed. Finally, instances from real road networks of England are performed with the ISA algorithm. Computational results show that our ISA algorithm performs well in a reasonable amount of time. We also find that when taking stochastic speeds into consideration, the fuel consumption is always larger than that with fixed speed model.

  20. Combined hydraulic and regenerative braking system

    Science.gov (United States)

    Venkataperumal, R.R.; Mericle, G.E.

    1979-08-09

    A combined hydraulic and regenerative braking system and method for an electric vehicle is disclosed. The braking system is responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

  1. ANALYSIS OF PERTURBED MOTION STABILITY OF WHEELER VEHICLES BRAKES CONTROL SYSTEM

    Directory of Open Access Journals (Sweden)

    V. Verbytskiyi

    2011-01-01

    Full Text Available The analysis of the perturbed motion stability of the brake automatic control system on the basis of Lyapunov’s second method is carried out. Using transformations of Lurie there has been ob-tained the canonical form of the system of equations of automatic control. It allowed determining the necessary and sufficient conditions of the asymptotic stability of the system irrespective of its initial condition and a definite choice of the admissible characteristic of the regulator.

  2. Braking materials for emergency stop device of super high speed elevator (810 m/min); 810 m/min erebeta hijo tome sochiyo masatsuzai

    Energy Technology Data Exchange (ETDEWEB)

    Okada, R.; Yamada, T.; Sugahara, J. [Hitachi Ltd., Tokyo (Japan)

    1995-04-20

    Accompanied with a super multistoried building, making the elevator a higher speed is essential and it requires for a performance rise not only on drive unit and control unit, but also on safety device as well, as for especially an emergency stop device to get the cage, which has a kinetic energy proportional to the square of speed, stopped, its performance improvement is indispensable. Because it was anticipated that a braking would become difficult with a speed exceeding 800 m/min by using the iron system materials centering around cast iron used conventionally, an emergency stop device using the special ceramics as a friction material has been developed. In order to develop an elevator with a super high speed of 810 m/min this time, a development of the friction material for emergency stop device, which can brake stably the cage with a kinetic energy substantially exceeding the conventional value, has been advanced. As a result, a strength drop at a high temperature was prevented by adding Cr, Ni and P, and moreover a cast iron with 1,5 times in mean friction coefficient and about 1/10 in specific abrasive quantity compared with FC 250 was developed, and furthermore an emergency stop device with a high performance, which guarantees more than 3 times of braking energy in the emergency stop device of elevator with a speed of 540 m/min, was realized. 5 refs., 8 figs., 1 tab.

  3. Military Hybrid Vehicle Survey

    Science.gov (United States)

    2011-08-03

    III Composite 4.3% Integrated starter generator for engine shut down, regenerative braking and avoidance of inefficient engine operation [28]. FMTV...eliminating the inefficiencies associated with idling, vehicle braking and low engine speed part load efficiency, many improvements can be realized...literature. They can be divided into the following two categories : (1) Time dependent speed profiles, shown in Figure 4, usually defined by the federal

  4. 49 CFR 393.55 - Antilock brake systems.

    Science.gov (United States)

    2010-10-01

    ... hydraulic braked vehicles. Each hydraulic braked vehicle subject to the requirements of paragraph (a) of...)). (2) Each air braked commercial motor vehicle other than a truck tractor, manufactured on or after... malfunction circuits and signals for air braked vehicles. (1) Each truck tractor manufactured on or after...

  5. The brake system of the future for commercial vehicles; Das Nutzfahrzeug Bremssystem der Zukunft

    Energy Technology Data Exchange (ETDEWEB)

    Gerum, E. [Knorr Bremse SfN GmbH (Germany)

    2004-07-01

    Over decades into the development of the CV brake system were indicated by an exponential growth in functionality and complexity. Another increase in functionality has to be expected in the future. The complexity must, however, be reduced by mechatronical integration to a measure so that it can be mastered by all ones involved. Bringing today's components together modularly becomes absolutely necessary. The long-term goal of a ''drive by Wire'' concept in connection with active safety systems requires a new infrastructure regarding information processing and electrical energy supply. Concepts are presented. (orig.)

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

    Science.gov (United States)

    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…

  7. Empirical analysis of gross vehicle weight and free flow speed and consideration on its relation with differential speed limit.

    Science.gov (United States)

    Saifizul, Ahmad Abdullah; Yamanaka, Hideo; Karim, Mohamed Rehan

    2011-05-01

    Most highly motorized countries in the world have implemented different speed limits for light weight and heavy weight vehicles. The heavy vehicle speed limit is usually chosen to be lower than that of passenger cars due to the difficulty for the drivers to safely maneuver the heavy vehicle at high speed and greater impact during a crash. However, in many cases, the speed limit for heavy vehicle is set by only considering the vehicle size or category, mostly due to simplicity in enforcement. In this study, traffic and vehicular data for all vehicle types were collected using a weigh-in-motion system installed at Federal Route 54 in Malaysia. The first finding from the data showed that the weight variation for each vehicle category is considerable. Therefore, the effect of gross vehicle weight (GVW) and category of heavy vehicle on free flow speed and their interaction were analyzed using statistical techniques. Empirical analysis results showed that statistically for each type of heavy vehicle, there was a significant relationship between free flow speed of a heavy vehicle and GVW. Specifically, the results suggest that the mean and variance of free flow speed decrease with an increase GVW by the amount unrelated to size and shape for all GVW range. Then, based on the 85th percentile principle, the study proposed a new concept for setting the speed limit for heavy vehicle by incorporating GVW where a different speed limit is imposed to the heavy vehicle, not only based on vehicle classification, but also according to its GVW. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Relationship Between Kinematic and Physiological Indices During Braking Events of Different Intensities.

    Science.gov (United States)

    Musicant, Oren; Botzer, Assaf; Laufer, Ilan; Collet, Christian

    2018-05-01

    Objective To study the relationship between physiological indices and kinematic indices during braking events of different intensities. Background Based on mental workload theory, driving and other task demands may generate changes in physiological indices, such as the driver's heart rate and skin conductance. However, no attempts were made to associate changes in physiological indices with changes in vehicle kinematics that result from the driver attempts to meet task demands. Method Twenty-five drivers participated in a field experiment. We manipulated braking demands using roadside signs to communicate the speed (km/h) before braking (50 or 60) and the target speed for braking (30 or to a complete stop). In an additional session, we asked drivers to brake as if they were responding to an impending collision. We analyzed the relationship between the intensities of braking events as measured by deceleration values (g) and changes in heart rate, heart rate variability, and skin conductance. Results All physiological indices were associated with deceleration intensity. Especially salient were the differences in physiological indices between the intensive (|g| > 0.5) and nonintensive braking events. The strongest relationship was between braking intensity and skin conductance. Conclusions Skin conductance, heart rate, and heart rate variability can mirror the mental workload elicited by varying braking intensities. Application Associating vehicle kinematics with physiological indices related to short-term driving events may help improve the performance of driver assistance systems.

  9. Analysis of Non-Tactical Vehicle Utilization at Fort Carson

    Science.gov (United States)

    2012-03-30

    regenerative braking energy recovery. The mass of the vehicles monitored in this study was not known. However, some useful information may be...regeneration to add braking action when the driver demand for deceleration rate exceeds the power absorption capability of the regenerative energy...recovery system (for instance, at the beginning of a hard brake from high speeds and as the vehicle comes to rest). This action decreases the overall

  10. Effects of automated speed enforcement in Montgomery County, Maryland, on vehicle speeds, public opinion, and crashes.

    Science.gov (United States)

    Hu, Wen; McCartt, Anne T

    2016-09-01

    In May 2007, Montgomery County, Maryland, implemented an automated speed enforcement program, with cameras allowed on residential streets with speed limits of 35 mph or lower and in school zones. In 2009, the state speed camera law increased the enforcement threshold from 11 to 12 mph over the speed limit and restricted school zone enforcement hours. In 2012, the county began using a corridor approach, in which cameras were periodically moved along the length of a roadway segment. The long-term effects of the speed camera program on travel speeds, public attitudes, and crashes were evaluated. Changes in travel speeds at camera sites from 6 months before the program began to 7½ years after were compared with changes in speeds at control sites in the nearby Virginia counties of Fairfax and Arlington. A telephone survey of Montgomery County drivers was conducted in Fall 2014 to examine attitudes and experiences related to automated speed enforcement. Using data on crashes during 2004-2013, logistic regression models examined the program's effects on the likelihood that a crash involved an incapacitating or fatal injury on camera-eligible roads and on potential spillover roads in Montgomery County, using crashes in Fairfax County on similar roads as controls. About 7½ years after the program began, speed cameras were associated with a 10% reduction in mean speeds and a 62% reduction in the likelihood that a vehicle was traveling more than 10 mph above the speed limit at camera sites. When interviewed in Fall 2014, 95% of drivers were aware of the camera program, 62% favored it, and most had received a camera ticket or knew someone else who had. The overall effect of the camera program in its modified form, including both the law change and the corridor approach, was a 39% reduction in the likelihood that a crash resulted in an incapacitating or fatal injury. Speed cameras alone were associated with a 19% reduction in the likelihood that a crash resulted in an

  11. The role of looming and attention capture in drivers' braking responses.

    Science.gov (United States)

    Terry, Hugh R; Charlton, Samuel G; Perrone, John A

    2008-07-01

    This study assessed the ability of drivers to detect the deceleration of a preceding vehicle in a simulated vehicle-following task. The size of the preceding vehicles (car, van, or truck) and following speeds (50, 70, or 100 km/h) were systematically varied. Participants selected a preferred following distance by engaging their vehicle's cruise control and when the preceding vehicle began decelerating (no brake lights were illuminated), the participant's braking latency and distances to the lead vehicle were recorded. The experiment also employed a secondary task condition to examine how the attention-capturing properties of a looming vehicle were affected by driver distraction. The results indicated that a looming stimulus is capable of redirecting a driver's attention in a vehicle following task and, as with detection of brake lights, a driver's detection of a looming vehicle is compromised in the presence of a distracting task. Interestingly, increases in vehicle size had the effect of decreasing drivers' braking latencies and drivers engaged in the secondary task were significantly closer to the lead vehicle when they began braking, regardless of the size of the leading vehicle. Performance decrements resulting from the secondary task were reflected in a time-to-collision measure but not in optic expansion rate, lending support to earlier arguments that time-to-collision estimates require explicit cognitive judgements while perception of optic expansion may function in a more automatic fashion to redirect a driver's attention when cognitive resources are low or collision is imminent.

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

    Science.gov (United States)

    Suzuki, Toru; Fujimoto, Hiroshi

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

  13. Design optimization of the transmission system for electric vehicles considering the dynamic efficiency of the regenerative brake

    NARCIS (Netherlands)

    Zhao, Bolin; Lv, Chen; Hofman, Theo; Steinbuch, Maarten; Zhang, Junzhi; Cao, Dongpu

    2018-01-01

    In this paper, gear ratios of a two-speed transmission system are optimized for an electric passenger car. Quasi static system models, including the vehicle model, the motor, the battery, the transmission system, and drive cycles are established in MATLAB/Simulink at first. Specifically, since the

  14. 49 CFR 393.43 - Breakaway and emergency braking.

    Science.gov (United States)

    2010-10-01

    ... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.43 Breakaway and emergency braking. (a) Towing vehicle protection system. Every motor vehicle, if used to tow a trailer equipped with brakes, shall be equipped with... brake systems installed on towed vehicles shall be so designed, by the use of “no-bleed-back” relay...

  15. Brake Performance Analysis of ABS for Eddy Current and Electrohydraulic Hybrid Brake System

    OpenAIRE

    Ren He; Xuejun Liu; Cunxiang Liu

    2013-01-01

    This paper introduces an eddy current and electro-hydraulic hybrid brake system to solve problems such as wear, thermal failure, and slow response of traditional vehicle brake system. Mathematical model was built to calculate the torque of the eddy current brake system and hydraulic brake system and analyze the braking force distribution between two types of brake systems. A fuzzy controller on personal computer based on LabVIEW and Matlab was designed and a set of hardware in the loop system...

  16. Variable friction device for structural control based on duo-servo vehicle brake: Modeling and experimental validation

    Science.gov (United States)

    Cao, Liang; Downey, Austin; Laflamme, Simon; Taylor, Douglas; Ricles, James

    2015-07-01

    Supplemental damping can be used as a cost-effective method to reduce structural vibrations. In particular, passive systems are now widely accepted and have numerous applications in the field. However, they are typically tuned to specific excitations and their performances are bandwidth-limited. A solution is to use semi-active devices, which have shown to be capable of substantially enhanced mitigation performance. The authors have recently proposed a new type of semi-active device, which consists of a variable friction mechanism based on a vehicle duo-servo drum brake, a mechanically robust and reliable technology. The theoretical performance of the proposed device has been previously demonstrated via numerical simulations. In this paper, we further the understanding of the device, termed Modified Friction Device (MFD) by fabricating a small scale prototype and characterizing its dynamic behavior. While the dynamics of friction is well understood for automotive braking technology, we investigate for the first time the dynamic behavior of this friction mechanism at low displacements and velocities, in both forward and backward directions, under various hydraulic pressures. A modified 3-stage dynamic model is introduced. A LuGre friction model is used to characterize the friction zone (Stage 1), and two pure stiffness regions to characterize the dynamics of the MFD once the rotation is reversed and the braking shoes are sticking to the drum (Stage 2) and the rapid build up of forces once the shoes are held by the anchor pin (Stage 3). The proposed model is identified experimentally by subjecting the prototype to harmonic excitations. It is found that the proposed model can be used to characterize the dynamics of the MFD, and that the largest fitting error arises at low velocity under low pressure input. The model is then verified by subjecting the MFD to two different earthquake excitations under different pressure inputs. The model is capable of tracking the

  17. Factors affecting speed in human-powered vehicles.

    Science.gov (United States)

    White, A P

    1994-10-01

    It is shown how to derive the appropriate cubic equation relating power and the effects of friction, gradient and wind resistance on the speed of a human-powered vehicle (HPV). The effects of gradient and wind resistance are explored for parameters representing a typical racing cyclist. The principal conclusion may be summarized as follows: for optimum performance in a time trial, there should be no wind and the course should be level. Any deviation from these conditions will produce a decrement in performance.

  18. MAINTAINING VEHICLE SPEED USING A MECHANICAL CRUISE CONTROL

    Directory of Open Access Journals (Sweden)

    Peter GIROVSKÝ

    2017-06-01

    Full Text Available In this article we would like to present cruise control realization. This cruise control is presented as mechanical device for vehicle speed maintenance and has been proposed as a low cost solution. Principle of function in mechanical cruise control is based on a position control of throttle. For the right action of mechanical cruise control it was need to solve some particular tasks related with speed sensing, construct of device for control of throttle position and design of control system of whole mechanical cruise control. Information about car velocity we have gained using Hall sensor attached on a magnetic ring of car tachometer. For control of the throttle was used a small servo drive and as the control unit was used Arduino. The designed solution of mechanical cruise control have been realized for car Škoda Felicia.

  19. Automatic braking system modification for the Advanced Transport Operating Systems (ATOPS) Transportation Systems Research Vehicle (TSRV)

    Science.gov (United States)

    Coogan, J. J.

    1986-01-01

    Modifications were designed for the B-737-100 Research Aircraft autobrake system hardware of the Advanced Transport Operating Systems (ATOPS) Program at Langley Research Center. These modifications will allow the on-board flight control computer to control the aircraft deceleration after landing to a continuously variable level for the purpose of executing automatic high speed turn-offs from the runway. A bread board version of the proposed modifications was built and tested in simulated stopping conditions. Test results, for various aircraft weights, turnoff speed, winds, and runway conditions show that the turnoff speeds are achieved generally with errors less than 1 ft/sec.

  20. Comparative analysis of two hybrid energy storage systems used in a two front wheel driven electric vehicle during extreme start-up and regenerative braking operations

    International Nuclear Information System (INIS)

    Itani, Khaled; De Bernardinis, Alexandre; Khatir, Zoubir; Jammal, Ahmad

    2017-01-01

    Highlights: • Comparison of HESS Ultracapacitor and Flywheel for maximizing EV energy recovery. • Energy recovery performed for extreme two front-wheel driven EV brake conditions. • Regenerative EV braking control strategies and constraints for HESS. • Comparative cost effectiveness for two HESS solutions Ultracapacitors and Flywheel. - Abstract: This paper presents the comparative study of two hybrid energy storage systems (HESS) of a two front wheel driven electric vehicle. The primary energy source of the HESS is a Li-Ion battery, whereas the secondary energy source is either an ultracapacitor (UC) or a flywheel energy system (FES). The main role of the secondary source is to deliver/recover energy during high peak power demand, but also to increase battery lifetime, considered among the most expensive items in the electric vehicle. As a first step, a techno-economic comparative study, supported by strong literature research, is performed between the UC and the FES. The design and sizing of each element will be presented. The comparison criteria and specifications are also described. The adopted approach in this paper is based on an academic non-oriented point of view. In a second step, each of the HESS will be integrated in a more global Simulink model which includes the vehicle model, the traction control system (TCS), the regenerative braking system and the vehicle actuators. Simulation tests are performed for an extreme braking and vehicle starting-up operations. Tests are realized on two different surface road types and conditions (high and low friction roads) and for different initial system states. In order to show the most appropriate storage system regarding compactness, weight and battery constraints minimization, deep comparative analysis is provided.

  1. The science of vehicle dynamics handling, braking, and ride of road and race cars

    CERN Document Server

    Guiggiani, Massimo

    2014-01-01

    Vehicle dynamics is often perceived as a quite intuitive subject. As a matter of fact, lots of people are able to drive a car. Nevertheless, without a rigorous mathematical formulation it is very difficult to truly understand the physical phenomena involved in the motion of a road vehicle. In this book, mathematical models of vehicles are developed, always paying attention to state the relevant assumptions and to provide explanations for each step. This approach allows for a deep, yet simple, analysis of the dynamics of vehicles, without having to resort to foggy concepts. The reader will soon achieve a clear understanding of the subject, which will be of great help both in dealing with the challenges of designing and testing new vehicles and in tackling new research topics. The book covers handling and performance of both road and race cars. A new approach, called MAP (Map of Achievable Performance), is presented and thoroughly discussed. It provides a global and intuitive picture of the handling features of...

  2. Experimental Verification of Discretely Variable Compression Braking Control for Heavy Duty Vehicles

    OpenAIRE

    Vahidi, Ardalan; Stefanopoulou, Anna G.; Farias, Phil; Tsao, Tsu Chin

    2003-01-01

    In this report a recursive least square scheme with multiple forgetting factors is proposed for on-line estimation of road grade and vehicle mass. The estimated mass and grade can be used to robustify many automatic controllers in conventional or automated heavy-duty vehicles. We demonstrate with measured test data from the July 26-27, 2002 test dates in San Diego, CA, that the proposed scheme estimates mass within 5% of its actual value and tracks grade with good accuracy. The experimental s...

  3. Real-Time Dynamic Brake Assessment Proof of Concept Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lascurain, Mary Beth [ORNL; Franzese, Oscar [ORNL; Capps, Gary J [ORNL

    2011-11-01

    This proof-of-concept research was performed to explore the feasibility of using real-world braking data from commercial motor vehicles to make a diagnosis of brake condition similar to that of the performance-based brake tester (PBBT). This was done by determining the relationship between pressure and brake force (P-BF), compensating for the gross vehicle weight (GVW). The nature of this P-BF relationship (e.g., low braking force for a given brake application pressure) may indicate brake system problems. In order to determine the relationship between brake force and brake application pressure, a few key parameters of duty cycle information were collected. Because braking events are often brief, spanning only a few seconds, a sample rate of 10 Hz was needed. The algorithm under development required brake application pressure and speed (from which deceleration was calculated). Accurate weight estimation was also needed to properly derive the braking force from the deceleration. In order to ensure that braking force was the predominant factor in deceleration for the segments of data used in analysis, the data was screened for grade as well. Also, the analysis needed to be based on pressures above the crack pressure. The crack pressure is the pressure below which the individual brakes are not applied due the nature of the mechanical system. This value, which may vary somewhat from one wheel end to another, is approximately 10 psi. Therefore, only pressures 15 psi and above were used in the analysis. The Department of Energy s Medium Truck Duty Cycle research has indicated that under the real-world circumstances of the test vehicle brake pressures of up to approximately 30 psi can be expected. Several different types of data were collected during the testing task of this project. Constant-pressure stopping tests were conducted at several combinations of brake application pressure (15, 20, 25, and 30 psi), load conditions (moderately and fully laden), and speeds (20 and

  4. Driver head displacement during (automatic) vehicle braking tests with varying levels of distraction

    NARCIS (Netherlands)

    Rooij, L. van; Pauwelussen, J.; Camp, O.M.G.C. op den; Janssen, J.M.

    2013-01-01

    Vehicle occupant behavior in emergency driving conditions has a large effect on traffic safety. Distraction is estimated to be the cause of 15-20% of all crashes. Additionally, the posture of the occupants prior to the possibly unavoidable crash is known to have a large effect on the injury reducing

  5. Full vehicle ABS braking using the SWIFT rigid ring tyre model

    NARCIS (Netherlands)

    Pauwelussen, J.P.; Gootjes, L.; Schröder, C.; Köhne, K.-U.; Jansen, S.T.H.; Schmeitz, A.J.C.

    2003-01-01

    In recent years, at the Delft University of Technology and TNO-Automotive and in conjunction with an industrial consortium, a pragmatic tyre model has been developed going by the name SWIFT, which is geared to the analysis of tyre oscillations and its effects on vehicle behaviour. The SWIFT tyre

  6. 75 FR 76487 - Haldex Brake Corporation, Commercial Vehicle Systems, Including On-Site Leased Workers of...

    Science.gov (United States)

    2010-12-08

    ..., Commercial Vehicle Systems, Including On-Site Leased Workers of Johnston Integration Technologies, a... Adjustment Assistance In accordance with Section 223 of the Trade Act of 1974, as amended (``Act''), 19 U.S.C... system components. The company reports that workers leased from Johnston Integration Technologies, a...

  7. Brakes, brake control and driver assistance systems function, regulation and components

    CERN Document Server

    2014-01-01

    Braking systems have been continuously developed and improved throughout the last years. Major milestones were the introduction of antilock braking system (ABS) and electronic stability program. This reference book provides a detailed description of braking components and how they interact in electronic braking systems. Contents Motor vehicle safety.- Basic principles of vehicle dynamics.- Car braking systems.- Car braking-system components.- Wheel brakes.- Antilock breaking systems.- Traction control system.- Electronic stability program.- Automatic brake functions.- Hydraulic modulator.- Sensors for brake control.- Sensotronic brake control.- Active steering.- Occupant protection systems.- Driver assistance systems.- Adaptive cruise control.- Parking systems.- Instrumentation.- Orientation methods.- Navigation systems.- Workshop technology. The target groups Motor-vehicle technicians in education and vocational training Master-mechanics and technicians in garage-workshops Teachers and lecturers in vocation...

  8. Vehicle speed guidance strategy at signalized intersection based on cooperative vehicle infrastructure system

    Directory of Open Access Journals (Sweden)

    Fengyuan JIA

    2017-10-01

    Full Text Available In order to reduce stopping time of vehicle at a signalized intersection, aiming at the difficulty, even the impossibility to obtain real-time queue length of intersection in third and fourth-tier cities in China sometimes, a speed guidance strategy based on cooperative vehicle infrastructure system is put forward and studied. For validating the strategy, the traffic signal timing data of the intersection at Hengshan Road and North Fengming Lake Road in Wuhu is collected by a vehicular traffic signal reminder system which is designed. The simulation experiments using the acquired data are done by software VISSIM. The simulation results demonstrate that the strategy under high and low traffic flow can effectively decrease the link travel-time, reducing average ratio is 9.2 % and 13.0 %, respectively, and the effect under low traffic flow is better than that under high traffic flow. The strategy improves efficiency of traffic at a signalized intersection and provides an idea for the application of vehicle speed guidance based on cooperative vehicle infrastructure system.

  9. Evaluation of sounds for hybrid and electric vehicles operating at low speed

    Science.gov (United States)

    2012-10-22

    Electric vehicles (EV) and hybrid electric vehicles (HEVs), operated at low speeds may reduce auditory cues used by pedestrians to assess the state of nearby traffic creating a safety issue. This field study compares the auditory detectability of num...

  10. On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles

    Science.gov (United States)

    2006-02-17

    On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles Report Title ABSTRACT In this work we proposed two semi-analytic...298-102 Enclosure 1 On-Line Path Generation and Tracking for High-Speed Wheeled Autonomous Vehicles by...Specifically, the following problems will be addressed during this project: 2.1 Challenges The problem of trajectory planning for high-speed autonomous vehicles is

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Shahaboddin Shamshirband

    Full Text Available 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.

  13. Transient switching control strategy from regenerative braking to anti-lock braking with a semi-brake-by-wire system

    Science.gov (United States)

    Li, Liang; Li, Xujian; Wang, Xiangyu; Liu, Yahui; Song, Jian; Ran, Xu

    2016-02-01

    Regenerative braking is an important technology in improving fuel economy of an electric vehicle (EV). However, additional motor braking will change the dynamic characteristics of the vehicle, leading to braking instability, especially when the anti-lock braking system (ABS) is triggered. In this paper, a novel semi-brake-by-wire system, without the use of a pedal simulator and fail-safe device, is proposed. In order to compensate for the hysteretic characteristics of the designed brake system while ensure braking reliability and fuel economy when the ABS is triggered, a novel switching compensation control strategy using sliding mode control is brought forward. The proposed strategy converts the complex coupling braking process into independent control of hydraulic braking and regenerative braking, through which a balance between braking performance, braking reliability, braking safety and fuel economy is achieved. Simulation results show that the proposed strategy is effective and adaptable in different road conditions while the large wheel slip rate is triggered during a regenerative braking course. The research provides a new possibility of low-cost equipment and better control performance for the regenerative braking in the EV and the hybrid EV.

  14. Comprehensive analysis of the carbon impacts of vehicle intelligent speed control

    Science.gov (United States)

    Carslaw, David C.; Goodman, Paul S.; Lai, Frank C. H.; Carsten, Oliver M. J.

    2010-07-01

    In recent years sophisticated technologies have been developed to control vehicle speed based on the type of road the vehicle is driven on using Global Positioning Systems and in-car technology that can alter the speed of the vehicle. While reducing the speed of road vehicles is primarily of interest from a safety perspective, vehicle speed is also an important determinant of vehicle emissions and thus these technologies can be expected to have impacts on a range of exhaust emissions. This work analyses the results from a very large, comprehensive field trial that used 20 instrumented vehicles with and without speed control driven almost 500,000 km measuring vehicle speed at 10 Hz. We develop individual vehicle modal emissions models for CO 2 for 30 Euro III and Euro IV cars at a 1-Hz time resolution. Generalized Additive Models were used to describe how emissions from individual vehicles vary depending on their driving conditions, taking account of variable interactions and time-lag effects. We quantify the impact that vehicle speed control has on-vehicle emissions of CO 2 by road type, fuel type and driver behaviour. Savings in CO 2 of ≈6% were found on average for motorway-type roads when mandatory speed control was used compared with base case conditions. For most other types of road, speed control has very little effect on emissions of CO 2 and in some cases can result in increased emissions for low-speed limit urban roads. We also find that there is on average a 20% difference in CO 2 emission between the lowest and highest emitting driver, which highlights the importance of driver behaviour in general as a means of reducing emissions of CO 2.

  15. Current State of Military Hybrid Vehicle Development

    Science.gov (United States)

    2011-08-31

    Integrated starter generator for engine shut down, regenerative braking and avoidance of inefficient engine operation [28]. FMTV VI Composite 6-9% Fuel...and eliminating the inefficiencies associated with idling, vehicle braking and low engine speed part load efficiency, many improvements could be...different drive cycles were being used to evaluate vehicle performance. These cycles can be divided into the following two categories : (1) Time

  16. Effects of cryogenic treatment on the wear properties of brake discs

    Science.gov (United States)

    Nadig, D. S.; Shivakumar, P.; Anoop, S.; Chinmay, Kulkarni; Divine, P. V.; Harsha, H. P.

    2017-02-01

    Disc brakes are invariably used in all the automobiles either to reduce the rotational speed of the wheel or to hold the vehicle stationary. During the braking action, the kinetic energy is converted into heat which can result in high temperatures resulting in fading of brake effects. Brake discs produced out of martensite stainless steel (SS410) are expected to exhibit high wear resistance properties with low value of coefficient of friction. These factors increase the useful life of the brake discs with minimal possibilities of brake fade. To study the effects of cryogenic treatment on the wear behaviour, two types of brake discs were cryotreated at 98K for 8 and 24 hours in a specially developed cryotreatment system using liquid nitrogen. Wear properties of the untreated and cryotreated test specimens were experimentally determined using the pin on disc type tribometer (ASTM G99-95). Similarly, the Rockwell hardness (HRC) of the specimens were tested in a hardness tester in accordance with ASTM E18. In this paper, the effects of cryotreatment on the wear and hardness properties of untreated and cryotreated brake discs are presented. Results indicate enhancement of wear properties and hardness after cryogenic treatment compared with the normal brakes discs.

  17. New Integrated Testing System for the Validation of Vehicle-Snow Interaction Models

    Science.gov (United States)

    2010-08-06

    are individual wheel speeds, accelerator pedal position, vehicle speed, yaw rate, lateral acceleration, steering wheel angle and brake ...forces and moments at each wheel center, vehicle body slip angle , speed, acceleration, yaw rate, roll, and pitch. The profilometer has a 3-D scanning...Stability Program. The test vehicle provides measurements that include three forces and moments at each wheel center, vehicle body slip angle , speed

  18. Motion Planning of Autonomous Vehicles on a Dual Carriageway without Speed Lanes

    Directory of Open Access Journals (Sweden)

    Rahul Kala

    2015-01-01

    Full Text Available The problem of motion planning of an autonomous vehicle amidst other vehicles on a straight road is considered. Traffic in a number of countries is unorganized, where the vehicles do not move within predefined speed lanes. In this paper, we formulate a mechanism wherein an autonomous vehicle may travel on the “wrong” side in order to overtake a vehicle. Challenges include assessing a possible overtaking opportunity, cooperating with other vehicles, partial driving on the “wrong” side of the road and safely going to and returning from the “wrong” side. The experimental results presented show vehicles cooperating to accomplish overtaking manoeuvres.

  19. Friction brake cushions acceleration and vibration loads

    Science.gov (United States)

    Fraser, G. F.; Zawadski, G. Z.

    1966-01-01

    Friction brake cushions an object in a vehicle from axially applied vibration and steady-state acceleration forces. The brake incorporates a doubly tapered piston that applies a controlled radial force to friction brake segments bearing against the walls of a cylinder.

  20. Nonlinear Output Feedback Control of Underwater Vehicle Propellers using Advance Speed Feedback

    DEFF Research Database (Denmark)

    Fossen, T.I.; Blanke, M.

    1999-01-01

    More accurate propeller shaft speed controllers can be designed by using nonlinear control theory. In this paper, an output feedback controller reconstructing the advance speed (speed of water going into the propeller) from vehicle speed measurements is derived. For this purpose a three-state model...... minimizes thruster losses due to variations in propeller axial inlet flow which is a major problem when applying conventional vehicle-propeller control systems. The proposed controller is simulated for an underwater vehicle equipped with a single propeller. From the simulations it can be concluded...... of propeller shaft speed, forward (surge) speed of the vehicle and axial inlet flow of the propeller is applied. A nonlinear observer in combination with an output feedback integral controller are derived by applying Lyapunov stability theory and exponential stability is proven. The output feedback controller...

  1. Time-varying delays compensation algorithm for powertrain active damping of an electrified vehicle equipped with an axle motor during regenerative braking

    Science.gov (United States)

    Zhang, Junzhi; Li, Yutong; Lv, Chen; Gou, Jinfang; Yuan, Ye

    2017-03-01

    The flexibility of the electrified powertrain system elicits a negative effect upon the cooperative control performance between regenerative and hydraulic braking and the active damping control performance. Meanwhile, the connections among sensors, controllers, and actuators are realized via network communication, i.e., controller area network (CAN), that introduces time-varying delays and deteriorates the control performances of the closed-loop control systems. As such, the goal of this paper is to develop a control algorithm to cope with all these challenges. To this end, the models of the stochastic network induced time-varying delays, based on a real in-vehicle network topology and on a flexible electrified powertrain, were firstly built. In order to further enhance the control performances of active damping and cooperative control of regenerative and hydraulic braking, the time-varying delays compensation algorithm for the electrified powertrain active damping during regenerative braking was developed based on a predictive scheme. The augmented system is constructed and the H∞ performance is analyzed. Based on this analysis, the control gains are derived by solving a nonlinear minimization problem. The simulations and hardware-in-loop (HIL) tests were carried out to validate the effectiveness of the developed algorithm. The test results show that the active damping and cooperative control performances are enhanced significantly.

  2. 49 CFR 393.49 - Control valves for brakes.

    Science.gov (United States)

    2010-10-01

    ... in paragraphs (b) and (c) of this section, every motor vehicle manufactured after June 30, 1953, which is equipped with power brakes, must have the braking system so arranged that one application valve must when activated cause all of the service brakes on the motor vehicle or combination motor vehicle...

  3. Gravity brake

    Science.gov (United States)

    Lujan, Richard E.

    2001-01-01

    A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

  4. Pedestrian injury mitigation by autonomous braking.

    Science.gov (United States)

    Rosén, Erik; Källhammer, Jan-Erik; Eriksson, Dick; Nentwich, Matthias; Fredriksson, Rikard; Smith, Kip

    2010-11-01

    The objective of this study was to calculate the potential effectiveness of a pedestrian injury mitigation system that autonomously brakes the car prior to impact. The effectiveness was measured by the reduction of fatally and severely injured pedestrians. The database from the German In-Depth Accident Study (GIDAS) was queried for pedestrians hit by the front of cars from 1999 to 2007. Case by case information on vehicle and pedestrian velocities and trajectories were analysed to estimate the field of view needed for a vehicle-based sensor to detect the pedestrians one second prior to the crash. The pre-impact braking system was assumed to activate the brakes one second prior to crash and to provide a braking deceleration up to the limit of the road surface conditions, but never to exceed 0.6 g. New impact speeds were then calculated for pedestrians that would have been detected by the sensor. These calculations assumed that all pedestrians who were within a given field of view but not obstructed by surrounding objects would be detected. The changes in fatality and severe injury risks were quantified using risk curves derived by logistic regression of the accident data. Summing the risks for all pedestrians, relationships between mitigation effectiveness, sensor field of view, braking initiation time, and deceleration were established. The study documents that the effectiveness at reducing fatally (severely) injured pedestrians in frontal collisions with cars reached 40% (27%) at a field of view of 40 degrees. Increasing the field of view further led to only marginal improvements in effectiveness. 2010 Elsevier Ltd. All rights reserved.

  5. 76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

    Science.gov (United States)

    2011-01-03

    ... [Docket No. NHTSA-2007-26851] Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter... occupants. IIHS stated that on-board electronic engine control modules (ECM) will maintain the desired speed... be equipped with an electronic control module (ECM) that is capable of limiting the maximum speed of...

  6. Heel and toe driving on fuel cell vehicle

    Science.gov (United States)

    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.

  7. Better Brakes

    Science.gov (United States)

    1976-01-01

    Through continuing studies on high-temperature space materials useful for better brake linings, Bendix Corporation worked with Ames Research Center to develop a novel composite. This team worked to fabricate several combinations of composite materials and evaluated results. The one selected increases wear rates and lowers costs. It exhibits constant coefficient of friction at temperatures as high as 650 degrees Fahrenheit, a region where conventional brake linings fade markedly. Other suitable markets include brakes for trucks and industrial equipment such as overhead cranes and hoists. Afterwards brake linings could find successful application in passenger cars.

  8. Batteries for Electric Vehicles

    Science.gov (United States)

    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.

  9. Estimation of longitudinal force, lateral vehicle speed and yaw rate for four-wheel independent driven electric vehicles

    Science.gov (United States)

    Chen, Te; Xu, Xing; Chen, Long; Jiang, Haobing; Cai, Yingfeng; Li, Yong

    2018-02-01

    Accurate estimation of longitudinal force, lateral vehicle speed and yaw rate is of great significance to torque allocation and stability control for four-wheel independent driven electric vehicle (4WID-EVs). A fusion method is proposed to estimate the longitudinal force, lateral vehicle speed and yaw rate for 4WID-EVs. The electric driving wheel model (EDWM) is introduced into the longitudinal force estimation, the longitudinal force observer (LFO) is designed firstly based on the adaptive high-order sliding mode observer (HSMO), and the convergence of LFO is analyzed and proved. Based on the estimated longitudinal force, an estimation strategy is then presented in which the strong tracking filter (STF) is used to estimate lateral vehicle speed and yaw rate simultaneously. Finally, co-simulation via Carsim and Matlab/Simulink is carried out to demonstrate the effectiveness of the proposed method. The performance of LFO in practice is verified by the experiment on chassis dynamometer bench.

  10. 49 CFR 393.40 - Required brake systems.

    Science.gov (United States)

    2010-10-01

    ... subpart. (2) Air brake systems. Buses, trucks and truck-tractors equipped with air brake systems and..., and 393.52 of this subpart. (4) Electric brake systems. Motor vehicles equipped with electric brake..., trucks and truck tractors manufactured on or after March 1, 1975, and trailers manufactured on or after...

  11. Model-Based Brake Control including Tyre Behaviour

    NARCIS (Netherlands)

    De Vries, E.J.H.

    2012-01-01

    The objective of the thesis is to develop a method for controlled braking of a vehicle. The brake pedal depression has been considered to be proportional to the intended deceleration. The brake controller is not aimed to replace a cruise control; it will have an anti-lock braking (ABS) function. The

  12. 49 CFR 393.41 - Parking brake system.

    Science.gov (United States)

    2010-10-01

    ... system shall, at all times, be capable of being applied by either the driver's muscular effort or by... 49 Transportation 5 2010-10-01 2010-10-01 false Parking brake system. 393.41 Section 393.41... NECESSARY FOR SAFE OPERATION Brakes § 393.41 Parking brake system. (a) Hydraulic-braked vehicles...

  13. Braking system

    Science.gov (United States)

    Norgren, D.U.

    1982-09-23

    A balanced braking system comprising a plurality of braking assemblies located about a member to be braked. Each of the braking assemblies consists of a spring biased piston of a first material fitted into a body of a different material which has a greater contraction upon cooling than the piston material. The piston is provided with a recessed head portion over which is positioned a diaphragm and forming a space therebetween to which is connected a pressurized fluid supply. The diaphragm is controlled by the fluid in the space to contact or withdraw from the member to be braked. A cooling means causes the body within which the piston is fitted to contract more than the piston, producing a tight shrink fit therebetween. The braking system is particularly applicable for selectively braking an arbor of an electron microscope which immobilizes, for example, a vertically adjustable low temperature specimen holder during observation. The system provides balanced braking forces which can be easily removed and re-established with minimal disturbance to arbor location.

  14. Developing of a software for determining advanced brake failures in brakes test bench

    Directory of Open Access Journals (Sweden)

    Hakan Köylü

    2016-08-01

    Full Text Available At present time, the brake test bench conducts the braking and suspension tests of front or rear axles and the test results are evaluated through one axle. The purpose of the brake testing system is to determine braking force and damping coefficient dissymmetry of one axle. Thus, this test system evaluates the performance of service brake, hand brake and suspension systems by considering separately front and rear axle dissymmetry. For this reason, the effects of different braking and damping forces applied by right and left wheels of both axles on braking performance of all vehicle are not determined due to available algorithm of the test bench. Also, the other brake failures are not occurred due to the algorithm of brake test system. In this study, the interface has been developed to determine the other effects of dissymmetry and the other brake failures by using the one axle results of brake test bench. The interface has algorithm computing the parameters according to the interaction between front and rear axles by only using measured test results. Also, it gives the warnings by comparing changes in the parameters with braking performance rules. Braking and suspension tests of three different vehicles have been conducted by using brake test bench to determine the performance of the algorithm. Parameters based on the axle interaction have been calculated by transferring brake test results to the interface and the test results have been evaluated. As a result, the effects of brake and suspension failures on braking performance of both axle and vehicle have been determined thanks to the developed interface.

  15. Magnetostrictive Brake

    Science.gov (United States)

    Diftler, Myron A.; Hulse, Aaron

    2010-01-01

    A magnetostrictive brake has been designed as a more energy-efficient alternative to a magnetic fail-safe brake in a robot. (In the specific application, failsafe signifies that the brake is normally engaged; that is, power must be supplied to allow free rotation.) The magnetic failsafe brake must be supplied with about 8 W of electric power to initiate and maintain disengagement. In contrast, the magnetostrictive brake, which would have about the same dimensions and the same torque rating as those of the magnetic fail-safe brake, would demand only about 2 W of power for disengagement. The brake (see figure) would include a stationary base plate and a hub mounted on the base plate. Two solenoid assemblies would be mounted in diametrically opposed recesses in the hub. The cores of the solenoids would be made of the magnetostrictive alloy Terfenol-D or equivalent. The rotating part of the brake would be a ring-and spring- disk subassembly. By means of leaf springs not shown in the figure, this subassembly would be coupled with the shaft that the brake is meant to restrain. With no power supplied to the solenoids, a permanent magnet would pull axially on a stepped disk and on a shelf in the hub, causing the ring to be squeezed axially between the stepped disk and the hub. The friction associated with this axial squeeze would effect the braking action. Supplying electric power to the solenoids would cause the magnetostrictive cylinders to push radially inward against a set of wedges that would be in axial contact with the stepped disk. The wedges would convert the radial magnetostrictive strain to a multiplied axial displacement of the stepped disk. This axial displacement would be just large enough to lift the stepped disk, against the permanent magnetic force, out of contact with the ring. The ring would then be free to turn because it would no longer be squeezed axially between the stepped disk and the hub.

  16. Vehicle Classification and Speed Estimation Using Combined Passive Infrared/Ultrasonic Sensors

    KAUST Repository

    Odat, Enas M.

    2017-09-18

    In this paper, a new sensing device that can simultaneously monitor traffic congestion and urban flash floods is presented. This sensing device is based on the combination of passive infrared sensors (PIRs) and ultrasonic rangefinder, and is used for real-time vehicle detection, classification, and speed estimation in the context of wireless sensor networks. This framework relies on dynamic Bayesian Networks to fuse heterogeneous data both spatially and temporally for vehicle detection. To estimate the speed of the incoming vehicles, we first use cross correlation and wavelet transform-based methods to estimate the time delay between the signals of different sensors. We then propose a calibration and self-correction model based on Bayesian Networks to make a joint inference by all sensors about the speed and the length of the detected vehicle. Furthermore, we use the measurements of the ultrasonic and the PIR sensors to perform vehicle classification. Validation data (using an experimental dual infrared and ultrasonic traffic sensor) show a 99% accuracy in vehicle detection, a mean error of 5 kph in vehicle speed estimation, a mean error of 0.7m in vehicle length estimation, and a high accuracy in vehicle classification. Finally, we discuss the computational performance of the algorithm, and show that this framework can be implemented on low-power computational devices within a wireless sensor network setting. Such decentralized processing greatly improves the energy consumption of the system and minimizes bandwidth usage.

  17. Adaptive controller for regenerative and friction braking system

    Science.gov (United States)

    Davis, Roy I.

    1990-01-01

    A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

  18. Design And Implementation Of Pc Based Over Speed Violation Management For Vehicles On Highway

    Directory of Open Access Journals (Sweden)

    Ni Ni Hlaing

    2015-07-01

    Full Text Available Abstract In the present day scenario traffic rules are frequently violated by the drivers and over speeding occur due to bad driving behavior. So a driver assistance system is provided to prevent over speeding violation of road rules also to display alert messages and gives alerts like road works steep slope school zone in the form of acoustical messages and also in LCD. The proposed system has a reporting displaying and database systemfor over speed violation management. This designed system has the ability to detect the speed of the vehicle in the roads and the main highways and the places where the drivers can use of more speed while driving. The laser transmitter senses the load entered by the vehicle and then the receiver unit sends to the microcontroller. The receiver unit is used by Light Dependent Resistor LDR. If the speed of vehicle exceeds the permissible speed for the highway this information will sent to PC which starts the camera to capture the vehicle. And all the information of vehicle are sent to database system. Then also shows the speed information on LCD.

  19. Investigation of new vehicle detectors for high-speed signalized intersections.

    Science.gov (United States)

    2015-09-01

    Early indications from the use of the newest vehicle detectors for high-speed signalized intersections : suggested that they perform well as replacements for the Texas Department of Transportations : (TxDOTs) legacy systems, but this early conc...

  20. The dynamic behaviour of rail vehicles operating at high speeds for manriding in British coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Manen, P. van

    1984-01-01

    The behaviour of trains used at high speeds for transporting men along mine railways is examined using a number of mathematical models. These models predict the responses of different rail vehicles to typical irregularities in the track, and are used to examine the guidance, the ride, and the likelihood of derailment of the main classes of manriding trains used in British coal mines. The outcome of the modelling compares favourably with the results of tests carried out on actual vehicles. The investigation has shown that the safe speed at which trains may operate is ultimately restricted by the condition of the track, but changes in the design of the vehicles can lead to an improved performance. The use of conventional wheelsets, for example, can reduce flange wear significantly and so allow higher speeds to be reached. Guidelines for the design of vehicles intended for high speed use are included in this thesis. (36 refs.)

  1. 49 CFR 236.701 - Application, brake; full service.

    Science.gov (United States)

    2010-10-01

    ... a split reduction in brake pipe pressure at a service rate until maximum brake cylinder pressure is developed. As applied to an automatic or electro-pneumatic brake with speed governor control, an application other than emergency which develops the maximum brake cylinder pressure, as determined by the design of...

  2. Modeling speed and width parameters of vehicle tires for prediction of the reduction in vehicle noise pollution

    Directory of Open Access Journals (Sweden)

    Amir Esmael Forouhid

    2016-06-01

    Full Text Available Introduction: Safe driving requires the ability of the driver to receive the messages and complying with them. The most significant consequences of noise pollution are on the human auditory system. Disorders in the auditory system can have harmful side effects for human health. By reducing this kind of pollution in large cities, the quality of life, which is one of the biggest goals of the governments, can be considerably increased. Hence, in the present research, some parameters of vehicle tires were examined as a source of noise pollution, and the results can be taken into consideration in noise pollution reduction. Material and Method: Several vehicles with different tire width were selected for measuring sound level. The sound levels were measured for moving vehicles with the use of the Statistical Pass By Method (SPB, ISO 11819-1. Following sound level measurements for moving vehicles and by considering tire width, mathematical model of noise level was predicted on the basis of the obtained information and by usage of SPSS program and considering vehicle tire parameters. Result: The result of this study showed that the vehicle speed and tire width can affect different sound levels emitted by moving tire on road surface. The average speed of vehicles can play an important role in the noise pollution. By increasing speed, rotation of the the tires on the asphalt is increased, as it is a known factors for noise pollution. Moreover, changing the speed of vehicles is accompanied with abnormal sounds of vehicle engine. According to regression model analysis, the obtained value of R2 for the model is 0.8367 which represents the coefficient of determination. Conclusion: The results suggest the main role of the vehicle speed and tire width in increasing the noise reaches to the drivers and consequent noise pollution, which demonstrates the necessity for noise control measures. According to the obtained model, it is understood that changes in noise

  3. Sensitivity Analysis of the Critical Speed in Railway Vehicle Dynamics

    DEFF Research Database (Denmark)

    Bigoni, Daniele; True, Hans; Engsig-Karup, Allan Peter

    2013-01-01

    -axle Cooperrider bogie, in order to study the sensitivity of the critical speed with respect to suspension parameters. The importance of a certain suspension component is expressed by the variance in critical speed that is ascribable to it. This proves to be useful in the identification of parameters for which...

  4. A Review of Vehicles Speed on School Safety Zone Areas in Pekanbaru City

    Science.gov (United States)

    Dwi Putri, Lusi; Soehardi, Fitridawati; Saleh, Alfian

    2017-12-01

    School Safety Zone is a location or region on particular roads that are time-based speed zone to set the speed of the vehicle in the school environment. The maximum speed limit permits entering a School Safety Zone, especially in Pekanbaru City is 25 km / h and an outline of the speed limit permit vehicles that pass through the School Safety Zone in Indonesia is generally 20-30 km / h. However, the vehicles speeds that pass School Safety Zone are higher than permit speeds.To ensure the level of vehicle offense across the territory of the School Safety Zone so it is necessary a primary data which is taken randomly based on field survey for 3 days at schools that has that facility ie SDN 3 Jalan Kesehatan Pekanbaru City, SDN 68 Jalan Balam Ujung Kota Pekanbaru and SDN 143 Jalan Taskurun Kota Pekanbaru. Furthermore, the data were taken in good condition that is at 6:30 to 7:30 am and at 12:00 to 13:00 pm. In addition, the data obtained is mileage and travel time of the vehicle. Both of these data can generate good speed value that passes through the area of School Safety Zone. Based on the research findings, the vehicle speed passing through the area of School Safety Zone is incompatible with speed permit at 35 km / h with a maximum average percentage of the rate of offense in the area of the school zone is 91.7%. This indicates that the vehicle passes School Safety Zone not following the rules of the maximum limit area and can be potentially harmful to elementary school students.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Joshué Pérez

    2010-06-01

    Full Text Available 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.

  8. Intersection Management Using In-Vehicle Speed Advisory/Adaptation

    OpenAIRE

    Rakha, Hesham; Bichiou, Youssef; Hassan, Abdallah; Zohdy, Ismail

    2016-01-01

    In recent years, connected vehicles (CVs) and automated vehicles (AVs) have emerged as a realistic and viable transportation option. Research centers and companies have dedicated substantial efforts to the technology, motivated largely by the potential safety benefits that can be realized through the elimination of human error, the enhancement of mobility via reduction of congestion and optimization of trips, and the associated positive environmental impacts. Both sensors and control mechanis...

  9. Sleep-related vehicle crashes on low speed roads.

    Science.gov (United States)

    Filtness, A J; Armstrong, K A; Watson, A; Smith, S S

    2017-02-01

    Very little is known about the characteristics of sleep related (SR) crashes occurring on low speed roads compared with current understanding of the role of sleep in crashes occurring on high speed roads e.g. motorways. To address this gap, analyses were undertaken to identify the differences and similarities between (1) SR crashes occurring on roads with low (≤60km/h) and high (≥100km/h) speed limits, and (2) SR crashes and not-SR crashes occurring on roads with low speed limits. Police reports of all crashes occurring on low and high speed roads over a ten year period between 2000 and 2009 were examined for Queensland, Australia. Attending police officers identified all crash attributes, including 'fatigue/fell asleep', which indicates that the police believe the crash to have a causal factor relating to falling asleep, sleepiness due to sleep loss, time of day, or fatigue. Driver or rider involvement in crashes was classified as SR or not-SR. All crash-associated variables were compared using Chi-square tests (Cramer's V=effect size). A series of logistic regression was performed, with driver and crash characteristics as predictors of crash category. A conservative alpha level of 0.001 determined statistical significance. There were 440,855 drivers or riders involved in a crash during this time; 6923 (1.6%) were attributed as SR. SR crashes on low speed roads have similar characteristics to those on high speed roads with young (16-24y) males consistently over represented. SR crashes on low speed roads are noticeably different to not-SR crashes in the same speed zone in that male and young novice drivers are over represented and outcomes are more severe. Of all the SR crashes identified, 41% occurred on low speed roads. SR crashes are not confined to high speed roads. Low speed SR crashes warrant specific investigation because they occur in densely populated areas, exposing a greater number of people to risk and have more severe outcomes than not-SR crashes

  10. Hardware simulation of automatic braking system based on fuzzy logic control

    Directory of Open Access Journals (Sweden)

    Noor Cholis Basjaruddin

    2016-07-01

    Full Text Available In certain situations, a moving or stationary object can be a barrier for a vehicle. People and vehicles crossing could potentially get hit by a vehicle. Objects around roads as sidewalks, road separator, power poles, and railroad gates are also a potential source of danger when the driver is inattentive in driving the vehicle. A device that can help the driver to brake automatically is known as Automatic Braking System (ABS. ABS is a part of the Advanced Driver Assistance Systems (ADAS, which is a device designed to assist the driver in driving the process. This device was developed to reduce human error that is a major cause of traffic accidents. This paper presents the design of ABS based on fuzzy logic which is simulated in hardware by using a remote control car. The inputs of fuzzy logic are the speed and distance of the object in front of the vehicle, while the output of fuzzy logic is the intensity of braking. The test results on the three variations of speed: slow-speed, medium-speed, and high-speed shows that the design of ABS can work according to design.

  11. Rail Brake System Using a Linear Induction Motor for Dynamic Braking

    Science.gov (United States)

    Sakamoto, Yasuaki; Kashiwagi, Takayuki; Tanaka, Minoru; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

    One type of braking system for railway vehicles is the eddy current brake. Because this type of brake has the problem of rail heating, it has not been used for practical applications in Japan. Therefore, we proposed the use of a linear induction motor (LIM) for dynamic braking in eddy current brake systems. The LIM reduces rail heating and uses an inverter for self excitation. In this paper, we estimated the performance of an LIM from experimental results of a fundamental test machine and confirmed that the LIM generates an approximately constant braking force under constant current excitation. At relatively low frequencies, this braking force remains unaffected by frequency changes. The reduction ratio of rail heating is also approximately proportional to the frequency. We also confirmed that dynamic braking resulting in no electrical output can be used for drive control of the LIM. These characteristics are convenient for the realization of the LIM rail brake system.

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

    Science.gov (United States)

    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.

  13. Electronic brakes. From ABS to brake-by-wire. 2. ed.; Elektronische Bremssysteme. Vom ABS zum Brake-by-Wire

    Energy Technology Data Exchange (ETDEWEB)

    Reichel, H.R.

    2003-07-01

    The book reports trends in vehicle brakes from 1968 to 1998. This was the age of the electronic revolution. The book presents conventional brakes, antiblocking systems (ABS), antislip systems (ASS), brake assistants (BAS), dynamic control systems, and brake-by-wire systems. [German] Das Buch berichtet ueber Entwicklungen an Fahrzeugbremsanlagen in der Zeitspanne von 1968 bis etwa 1998. Diese Zeit war gepraegt vom Vordringen der Elektronik in die Bremsen, was fuer Hersteller und Kunden eine Revolution bedeutete. Behandelt sind: (a) Konventionelle Bremsanlagen, (b) Antiblockiersysteme (ABS), (c) Anti-Schlupf-regelungen (ASR), (d) Bremsassistenten (BAS), (e) Fahrdynamikregelungen (FDR, ESP), (f) Brake-by-Wire (orig.)

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

    Science.gov (United States)

    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

  15. Smart Sensor Based Obstacle Detection for High-Speed Unmanned Surface Vehicle

    DEFF Research Database (Denmark)

    Hermann, Dan; Galeazzi, Roberto; Andersen, Jens Christian

    2015-01-01

    This paper describes an obstacle detection system for a high-speed and agile unmanned surface vehicle (USV), running at speeds up to 30 m/s. The aim is a real-time and high performance obstacle detection system using both radar and vision technologies to detect obstacles within a range of 175 m. ...... performance using sensor fusion of radar and computer vision....

  16. Studying the Effect of Roughness of Wet Road on Critical speed of Vehicle

    Directory of Open Access Journals (Sweden)

    Ali K. Mohammed

    2018-01-01

    Full Text Available Hydroplaning is one the most dangerous phenomena which effect on the safety of driving cars on wet roads, then, the critical speed of slipping cars is an important parameter in the hydroplaning ,and depends on the properties of  the following three  parameters: tires, water layer and  road surface. The road texture is the main property of road specifications which affect directly on the critical speed of the vehicle. In the present work, the properties of road roughness and influence of surface texture on critical speed of vehicle are studied with variation of the following parameters: thickness and dynamic viscosity of water on the road surface and the vehicle load. The results showed that increasing the road surface roughness and the vehicle load both has a appositive influence on the critical speed (increaseof the vehicle, while increasing the dynamic viscosity and thickness of the water layer on the road surface has a negative influence on the critical speed (decrease of the vehicle. DOI: http://dx.doi.org/10.25130/tjes.24.2017.24

  17. EVALUATION METHOD OF FUEL-EFFICIENT DRIVING IN DUMP TRUCK USING VEHICLE SPEED AND ENGINE ROTATIONAL SPEED

    Science.gov (United States)

    Hirata, Masafumi; Yamamoto, Tatsuo; Yasui, Toshiaki; Hayashi, Mayu; Takebe, Atsuji; Funahashi, Masashi

    In the construction site, the light oil that the construction vehicle such as dump trucks uses accounts for 70 percent of the amount of the energy use. Therefore, the eco-driving education of the construction vehicle is effective in the fuel cost improvement and the CO2 reduction. The eco-driving education can be executed cheap and easily, and a high effect can be expected. However, it is necessary to evaluate the eco-driving situation of the construction vehicle exactly to maintain the educative effect for a long term. In this paper, the method for evaluating the effect of the fuel cost improvement was examined by using the vehicle speed and the engine rotational speed of the dump truck. In this method, "Ideal eco-driving model" that considers the difference between the vehicle model and the running condition (traffic jam etc.) is made. As a result, it is possible to evaluate the fuel consumption improvement effect of a dump truck by the same index.

  18. Increasing accuracy of vehicle detection from conventional vehicle detectors - counts, speeds, classification, and travel time.

    Science.gov (United States)

    2014-09-01

    Vehicle classification is an important traffic parameter for transportation planning and infrastructure : management. Length-based vehicle classification from dual loop detectors is among the lowest cost : technologies commonly used for collecting th...

  19. Usage of aids monitoring in automatic braking systems of modern cars

    Directory of Open Access Journals (Sweden)

    Dembitskyi V.

    2016-08-01

    Full Text Available Increased safety can be carried out at the expense the installation on vehicles of automatic braking systems, that monitor the traffic situation and the actions of the driver. In this paper considered the advantages and disadvantages of automatic braking systems, were analyzed modern tracking tools that are used in automatic braking systems. Based on the statistical data on accidents, are set the main dangers, that the automatic braking system will be reduced. In order to ensure the accuracy of information conducted research for determination of optimal combination of different sensors that provide an adequate perception of road conditions. The tracking system should be equipped with a combination of sensors, which in the case of detection of an obstacle or dangers of signal is transmitted to the information processing system and decision making. Information from the monitoring system should include data for the identification of the object, its condition, the speed.

  20. Vehicle speed detection based on gaussian mixture model using sequential of images

    Science.gov (United States)

    Setiyono, Budi; Ratna Sulistyaningrum, Dwi; Soetrisno; Fajriyah, Farah; Wahyu Wicaksono, Danang

    2017-09-01

    Intelligent Transportation System is one of the important components in the development of smart cities. Detection of vehicle speed on the highway is supporting the management of traffic engineering. The purpose of this study is to detect the speed of the moving vehicles using digital image processing. Our approach is as follows: The inputs are a sequence of frames, frame rate (fps) and ROI. The steps are following: First we separate foreground and background using Gaussian Mixture Model (GMM) in each frames. Then in each frame, we calculate the location of object and its centroid. Next we determine the speed by computing the movement of centroid in sequence of frames. In the calculation of speed, we only consider frames when the centroid is inside the predefined region of interest (ROI). Finally we transform the pixel displacement into a time unit of km/hour. Validation of the system is done by comparing the speed calculated manually and obtained by the system. The results of software testing can detect the speed of vehicles with the highest accuracy is 97.52% and the lowest accuracy is 77.41%. And the detection results of testing by using real video footage on the road is included with real speed of the vehicle.

  1. Two wheel speed robust sliding mode control for electric vehicle drive

    Directory of Open Access Journals (Sweden)

    Abdelfatah Nasri

    2008-01-01

    Full Text Available Nowadays the uses of electrical power resources are integrated in the modern vehicle motion traction chain so new technologies allow the development of electric vehicles (EV by means of static converters-related electric motors. All mechanical transmission devices are eliminated and vehicle wheel motion can be controlled by means of power electronics. The proposed propulsing system consists of two induction motors (IM that ensure the drive of the two back driving wheels. The proposed control structure-called independent machines- for speed control permit the achievement of an electronic differential. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling independently, every driving wheel to turn at different speeds in any curve. This paper presents the study and the sliding mode control strategy of the electric vehicle driving wheels.

  2. An analysis of braking measures

    OpenAIRE

    De Groot, S.; De Winter, J.C.F.; Wieringa, P.A.; Mulder, M.

    2010-01-01

    Braking to a full stop at a prescribed target position is a driving manoeuvre regularly used in experiments to investigate driving behaviour or to test vehicle acceleration feedback systems in simulators. Many different performance measures have been reported in the literature for analysing braking. These may or may not be useful to analyse the stopping manoeuvre, because a number of potential problems exist: 1) the scores on a measure may be insufficiently reliable, 2) the measure may be inv...

  3. Speed Loop Control of PMSM Driving Electric Vehicle

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong

    2011-01-01

    Various simulation models are set up and closed speed loop control strategy of PMSM is proposed based on flux weakening control in this paper. First the model of maximum torque per ampere(MTPA) is modeled based on mathematical models and gave the corresponding simulation tests. Second the formula...

  4. Capacitated Vehicle Routing with Non-Uniform Speeds

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Molinaro, Marco; Nagarajan, Viswanath

    2011-01-01

    -uniform speeds (that we call Heterogenous CVRP), and present a constant-factor approximation algorithm. The technical heart of our result lies in achieving a constant approximation to the following TSP variant (called Heterogenous TSP). Given a metric denoting distances between vertices, a depot r containing k...

  5. 49 CFR 579.21 - Reporting requirements for manufacturers of 5,000 or more light vehicles annually.

    Science.gov (United States)

    2010-10-01

    ... structure, 17 latch, 18 vehicle speed control, 19 tires, 20 wheels, 22 seats, 23 fire, 24 rollover, 98 where... the incident involved a fire or rollover, coded as follows: 01 steering system, 02 suspension system, 03 service brake system, 05 parking brake, 06 engine and engine cooling system, 07 fuel system, 10...

  6. Modeling and predicting low-speed vehicle emissions as a function of driving kinematics.

    Science.gov (United States)

    Hao, Lijun; Chen, Wei; Li, Lei; Tan, Jianwei; Wang, Xin; Yin, Hang; Ding, Yan; Ge, Yunshan

    2017-05-01

    An instantaneous emission model was developed to model and predict the real driving emissions of the low-speed vehicles. The emission database used in the model was measured by using portable emission measurement system (PEMS) under actual traffic conditions in the rural area, and the characteristics of the emission data were determined in relation to the driving kinematics (speed and acceleration) of the low-speed vehicle. The input of the emission model is driving cycle, and the model requires instantaneous vehicle speed and acceleration levels as input variables and uses them to interpolate the pollutant emission rate maps to calculate the transient pollutant emission rates, which will be accumulated to calculate the total emissions released during the whole driving cycle. And the vehicle fuel consumption was determined through the carbon balance method. The model predicted the emissions and fuel consumption of an in-use low-speed vehicle type model, which agreed well with the measured data. Copyright © 2016. Published by Elsevier B.V.

  7. Experimental study of the vehicle dynamics behavior during lane changing in different speeds

    Science.gov (United States)

    Heerwan, P. M.; Asyraf, S. M.; Efistein, A. N.; Seah, C. H.; Zikri, J. M.; Syawahieda, J. N.

    2017-10-01

    During lane changing, the speed of the vehicle is related to the stability of the vehicle. If the driver changes the lane at a high speed, the vehicle will lose its stability and it can increase the possibility of an accident. In this study, the experiment has been developed to analyse how the speed of the vehicle can affect the vehicle dynamics behavior. To achieve this objective, the UMP Test Car which employed with global positioning system (GPS), steering torque and angle sensor, displacement sensor and gyro sensor is used in the experiment. The experiment is run at the UMP test track and the track has 2 lanes which can allows the vehicle to change the position from the left to the right. In the experiment, when the GPS monitor shows 30 km/h, the driver will maintain the speed and start to turn the steering just after the test car reaches to the first skittle. Then, the driver will turn again the steering when the test car reaches to the second skittle. This method is repeated two times and the same methods is used for the speed 50 km/h. The data from the sensors is recorded in the Dewetron software and the graph is plotted. From the experimental results, the steering angle, steering torque, yaw rate and displacement for the speed 30 km/h is smaller than 50 km/h. It means that during lane changing, the speed 30 km/h is more stable compared with 50 km/h.

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

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hwang, Ho-Ling [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); West, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Huff, Shean [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2013-04-08

    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.

  9. BASIC STUDY ON TAILORMADE BRAKING SUPPORT SYSTEM

    Directory of Open Access Journals (Sweden)

    Toshiya HIROSE, M.S.

    2004-01-01

    This research reviewed the construction of models of a Tailormade Braking Support System (TBSS for braking to stop vehicles and the evaluation of drivers. As a result, the following conclusions were drawn. (1 Braking factors were found to change in the period from the start of braking to stopping; (2 Changes in braking factors can be logically incorporated into the control elements of braking support system; (3 Readymade Driver Model is effective as a model to be incorporated into the base system of TBSS; (4 Tailormade Driver Model built on Neural Network is effective as a main model to construct TBSS; (5 As for TBSS, both subjective and objective ratings on the timing and magnitude of braking are favorable, and its safety and sense of security are improved.

  10. Study on Parameter Optimization Design of Drum Brake Based on Hybrid Cellular Multiobjective Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2012-01-01

    Full Text Available In consideration of the significant role the brake plays in ensuring the fast and safe running of vehicles, and since the present parameter optimization design models of brake are far from the practical application, this paper proposes a multiobjective optimization model of drum brake, aiming at maximizing the braking efficiency and minimizing the volume and temperature rise of drum brake. As the commonly used optimization algorithms are of some deficiency, we present a differential evolution cellular multiobjective genetic algorithm (DECell by introducing differential evolution strategy into the canonical cellular genetic algorithm for tackling this problem. For DECell, the gained Pareto front could be as close as possible to the exact Pareto front, and also the diversity of nondominated individuals could be better maintained. The experiments on the test functions reveal that DECell is of good performance in solving high-dimension nonlinear multiobjective problems. And the results of optimizing the new brake model indicate that DECell obviously outperforms the compared popular algorithm NSGA-II concerning the number of obtained brake design parameter sets, the speed, and stability for finding them.

  11. Assessment of capacity support and scattering in experimental high speed vehicle to vehicle MIMO links

    DEFF Research Database (Denmark)

    Eggers, Patrick Claus F.; Brown, Tim; Olesen, Kim

    2007-01-01

    Preliminary results on the use of the vehicle to vehicle MIMO channel in a rural highway environment are presented. This is looked at both in terms of the available spatial multiplexing through singular value decomposition and also angular distribution within the channel. Results indicate a strong...... predominant line of sight link in general while instances of scattering from other vehicles will cause changes in the Doppler spectrum as well as beamforming jitter....

  12. Vibrational Comfort on Board the Vehicle: Influence of Speed Bumps and Comparison between Different Categories of Vehicle

    Directory of Open Access Journals (Sweden)

    Vincenzo Barone

    2016-01-01

    Full Text Available This paper shows the results of a study conducted on five different categories of vehicles in a specific test site. The aim was to investigate how the effect of the test site discontinuity determines variations of comfort related to the increase in speed and to the five selected road vehicles of different classes. Measurements were obtained by combining data relating to vibrations in the three reference axes, detected through a vibration dosimeter (VIB-008, and geolocation data (latitude, longitude, and speed identified by the GPS inside a smartphone. This procedure, through the synchronization between dosimeter and GPS location, has been helpful in postprocessing to eliminate any measurement anomalies generated by the operator. After the survey campaign it was determined that a formulation allows defining a Comfort Index (CI depending on velocity and five vehicles of different classes. This study showed that the presence of speed bumps, in the test site investigated, appears to be uncomfortable even at speeds well below those required by the Highway Code.

  13. Tether Deployer And Brake

    Science.gov (United States)

    Carroll, Joseph A.; Alexander, Charles M.

    1993-01-01

    Design concept promises speed, control, and reliability. Scheme for deploying tether provides for fast, free, and snagless payout and fast, dependable braking. Developed for small, expendable tethers in outer space, scheme also useful in laying transoceanic cables, deploying guidance wires to torpedoes and missiles, paying out rescue lines from ship to ship via rockets, deploying antenna wires, releasing communication and power cables to sonobuoys and expendable bathythermographs, and in reeling out lines from fishing rods.

  14. The reliability assessment of the electromagnetic valve of high-speed electric multiple units braking system based on two-parameter exponential distribution

    Directory of Open Access Journals (Sweden)

    Jianwei Yang

    2016-06-01

    Full Text Available In order to solve the reliability assessment of braking system component of high-speed electric multiple units, this article, based on two-parameter exponential distribution, provides the maximum likelihood estimation and Bayes estimation under a type-I life test. First of all, we evaluate the failure probability value according to the classical estimation method and then obtain the maximum likelihood estimation of parameters of two-parameter exponential distribution by performing and using the modified likelihood function. On the other hand, based on Bayesian theory, this article also selects the beta and gamma distributions as the prior distribution, combines with the modified maximum likelihood function, and innovatively applies a Markov chain Monte Carlo algorithm to parameters assessment based on Bayes estimation method for two-parameter exponential distribution, so that two reliability mathematical models of the electromagnetic valve are obtained. Finally, through type-I life test, the failure rates according to maximum likelihood estimation and Bayes estimation method based on Markov chain Monte Carlo algorithm are, respectively, 2.650 × 10−5 and 3.037 × 10−5. Compared with the failure rate of a electromagnetic valve 3.005 × 10−5, it proves that the Bayes method can use a Markov chain Monte Carlo algorithm to estimate reliability for two-parameter exponential distribution and Bayes estimation is more closer to the value of electromagnetic valve. So, by fully integrating multi-source, Bayes estimation method can preferably modify and precisely estimate the parameters, which can provide a certain theoretical basis for the safety operation of high-speed electric multiple units.

  15. Evaluation of uncertainty of vehicle speed when autotechnical examination of traffic accidents

    Directory of Open Access Journals (Sweden)

    Kashkanov А.А.

    2016-08-01

    Full Text Available The existing methods and ways to measure vehicle speed, which can be used in autotechnical examination of road accidents, in order to identify ways to improve the peer review mechanism of emergencies are analyzed. To achieve the goal we propose to take measurement errors vehicle speed into account. Modern automated technology (GPS, EDR and ACN can reduce these errors, and with sufficient accuracy to determine the speed of the vehicle and other motion parameters and technical data that helps to quicken research in various stages of examination, but there are a number of objective problems hindering their widespread use in Ukraine. To solve these problems need to develop and improve existing methods of expert investigation of the circumstances of accidents based process automation capabilities fixing mechanism and the scene, measurements and calculations options vehicular traffic. This will increase the effectiveness of traditional methods and to minimize the influence of subjective factors.

  16. Feedback brake distribution control for minimum pitch

    Science.gov (United States)

    Tavernini, Davide; Velenis, Efstathios; Longo, Stefano

    2017-06-01

    The distribution of brake forces between front and rear axles of a vehicle is typically specified such that the same level of brake force coefficient is imposed at both front and rear wheels. This condition is known as 'ideal' distribution and it is required to deliver the maximum vehicle deceleration and minimum braking distance. For subcritical braking conditions, the deceleration demand may be delivered by different distributions between front and rear braking forces. In this research we show how to obtain the optimal distribution which minimises the pitch angle of a vehicle and hence enhances driver subjective feel during braking. A vehicle model including suspension geometry features is adopted. The problem of the minimum pitch brake distribution for a varying deceleration level demand is solved by means of a model predictive control (MPC) technique. To address the problem of the undesirable pitch rebound caused by a full-stop of the vehicle, a second controller is designed and implemented independently from the braking distribution in use. An extended Kalman filter is designed for state estimation and implemented in a high fidelity environment together with the MPC strategy. The proposed solution is compared with the reference 'ideal' distribution as well as another previous feed-forward solution.

  17. An examination of vehicles at the brake-chassis test bed in the range of the partial engine load

    Directory of Open Access Journals (Sweden)

    Paweł MARZEC

    2017-06-01

    Full Text Available The performance of a ZI engine is presented in the paper, as well as a project involving a device for applying a partial load in the performed examinations of a brakechassis test bed. The device was prepared for an Opel Astra and enabled the determination of exterior characteristics of the engine for different values of the engine load. The indicating pressure sensor and the angle marker on the crankshaft allowed for the recording of the indicating pressure obtained at different values of the load. The analysis of heat evolution in the process of burning, based on the registered results of the measurements at the brake-chassis test bed, has also been included in the presentation.

  18. Design and Analysis of a Novel Centrifugal Braking Device for a Mechanical Antilock Braking System.

    Science.gov (United States)

    Yang, Cheng-Ping; Yang, Ming-Shien; Liu, Tyng

    2015-06-01

    A new concept for a mechanical antilock braking system (ABS) with a centrifugal braking device (CBD), termed a centrifugal ABS (C-ABS), is presented and developed in this paper. This new CBD functions as a brake in which the output braking torque adjusts itself depending on the speed of the output rotation. First, the structure and mechanical models of the entire braking system are introduced and established. Second, a numerical computer program for simulating the operation of the system is developed. The characteristics of the system can be easily identified and can be designed with better performance by using this program to studying the effects of different design parameters. Finally, the difference in the braking performance between the C-ABS and the braking system with or without a traditional ABS is discussed. The simulation results indicate that the C-ABS can prevent the wheel from locking even if excessive operating force is provided while still maintaining acceptable braking performance.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Miguel Angel Olivares-Mendez

    2016-03-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  2. A Minimization of Speed Ripple of Sensorless DTC for controlled Induction Motors used in Electric Vehicles

    OpenAIRE

    Khoucha , Farid; Marouani , Khoudir; Kheloui , Abdelaziz; Benbouzid , Mohamed

    2006-01-01

    International audience; The main theme of this paper is to present different switching techniques in DTC induction motor drives for electric vehicle applications, witch insert zero-voltage vector and/or more non zero-voltage vectors to the conventional switching table associated to full adaptive flux and speed observer. Those techniques are quite effective in reducing the torque pulsation and the speed ripples of the motors, as demonstrated in experimental results.

  3. BRAKE DEVICE

    Science.gov (United States)

    O'Donnell, T.J.

    1959-03-10

    A brake device is described for utilization in connection with a control rod. The device comprises a pair of parallelogram link mechanisms, a control rod moveable rectilinearly therebetween in opposite directions, and shoes resiliently supported by the mechanism for frictional engagement with the control rod.

  4. Aerothermodynamics of expert ballistic vehicle at hypersonic speeds

    Science.gov (United States)

    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.

  5. Design and analysis of an MR rotary brake for self-regulating braking torques.

    Science.gov (United States)

    Yun, Dongwon; Koo, Jeong-Hoi

    2017-05-01

    This paper presents a novel Magneto-rheological (MR) brake system that can self-regulate the output braking torques. The proposed MR brake can generate a braking torque at a critical rotation speed without an external power source, sensors, or controllers, making it a simple and cost-effective device. The brake system consists of a rotary disk, permanent magnets, springs, and MR fluid. The permanent magnets are attached to the rotary disk via the springs, and they move outward through grooves with two different gap distances along the radial direction of the stator due to the centrifugal force. Thus, the position of the magnets is dependent on the spin speed, and it can determine the magnetic fields applied to MR fluids. Proper design of the stator geometry gives the system unique torque characteristics. To show the performance of an MR brake system, the electromagnetic characteristics of the system are analyzed, and the torques generated by the brake are calculated using the result of the electromagnetic analysis. Using a baseline model, a parametric study is conducted to investigate how the design parameters (geometric shapes and material selection) affect the performance of the brake system. After the simulation study, a prototype brake system is constructed and its performance is experimentally evaluated. The experimental results show that the prototype produced the maximum torque of 1.2 N m at the rotational speed of 100 rpm. The results demonstrate the feasibility of the proposed MR brake as a speed regulator in rotating systems.

  6. Design And Analysis Of Doppler Radar-Based Vehicle Speed Detection

    Directory of Open Access Journals (Sweden)

    Su Myat Paing

    2015-08-01

    Full Text Available The most unwanted thing to happen to a road user is road accident. Most of the fatal accidents occur due to over speeding. Faster vehicles are more prone to accident than the slower one. Among the various methods for detecting speed of the vehicle object detection systems based on Radar have been replaced for about a century for various purposes like detection of aircrafts spacecraft ships navigation reading weather formations and terrain mapping. The essential feature in adaptive vehicle activated sign systems is the accurate measurement of a vehicles velocity. The velocities of the vehicles are acquired from a continuous wave Doppler radar. A very low amount of power is consumed in this system and only batteries can use to operate. The system works on the principle of Doppler Effect by detecting the Doppler shift in microwaves reflected from a moving object. Since the output of the sensor is sinusoidal wave with very small amplitude and needs to be amplified with the help of the amplifier before further processing. The purpose to calculate and display the speed on LCD is performed by the microcontroller.

  7. Detection of visually unrecognizable braking tracks using Laser-Induced Breakdown Spectroscopy, a feasibility study

    Science.gov (United States)

    Prochazka, David; Bilík, Martin; Prochazková, Petra; Brada, Michal; Klus, Jakub; Pořízka, Pavel; Novotný, Jan; Novotný, Karel; Ticová, Barbora; Bradáč, Albert; Semela, Marek; Kaiser, Jozef

    2016-04-01

    Identification of the position, length and mainly beginning of a braking track has proven to be essential for determination of causes of a road traffic accident. With the introduction of modern safety braking systems and assistance systems such as the Anti-lock Braking System (ABS) or Electronic Stability Control (ESC), the visual identification of braking tracks that has been used up until the present is proving to be rather complicated or even impossible. This paper focuses on identification of braking tracks using a spectrochemical analysis of the road surface. Laser-Induced Breakdown Spectroscopy (LIBS) was selected as a method suitable for fast in-situ element detection. In the course of detailed observations of braking tracks it was determined that they consist of small particles of tire treads that are caught in intrusions in the road surface. As regards detection of the "dust" resulting from wear and tear of tire treads in the environment, organic zinc was selected as the identification element in the past. The content of zinc in tire treads has been seen to differ with regard to various sources and tire types; however, the arithmetic mean and modus of these values are approximately 1% by weight. For in-situ measurements of actual braking tracks a mobile LIBS device equipped with a special module was used. Several measurements were performed for 3 different cars and tire types respectively which slowed down with full braking power. Moreover, the influence of different initial speed, vehicle mass and braking track length on detected signal is discussed here.

  8. Air brake-dynamometer accurately measures torque

    Science.gov (United States)

    1965-01-01

    Air brake-dynamometer assembly combines the principles of the air turbine and the air pump to apply braking torque. The assembly absorbs and measures power outputs of rotating machinery over a wide range of shaft speeds. It can also be used as an air turbine.

  9. 76 FR 9717 - Parts and Accessories Necessary for Safe Operation; Saddle-Mount Braking Requirements

    Science.gov (United States)

    2011-02-22

    ...\\ Radlinski & Associates, Inc. Vehicle Systems Consultants (May 2003). ``Braking Performance of Saddlemount... of the last vehicle tends to lock up under heavy braking, and submitted test results supporting this... vehicle tends to lock up under heavy braking, potentially increasing stopping distance. Stopping distances...

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

    Science.gov (United States)

    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.

  11. Cooperative Intelligence in Roundabout Intersections Using Hierarchical Fuzzy Behavior Calculation of Vehicle Speed Profile

    Directory of Open Access Journals (Sweden)

    Bosankić Ivan

    2016-01-01

    Full Text Available In this paper, a new fuzzy-behavior-based algorithm for roundabout intersection management is presented. The algorithm employs cooperative intelligence and includes intelligent vehicles and infrastructure to calculate speed profiles for different vehicles, in order to achieve more comfortable driving profiles, as well to reduce congestion and CO2 emissions. The algorithm uses adaptive spatio-temporal reservation technique and was tested in MATLAB/Simulink environment. The algorithm is designed to function in different scenarios with both cooperative and non-cooperative vehicles, as well as optional intersection infrastructure. Results have show that using the proposed algorithm different vehicle communication types can be successfully combined in order to increase traffic flow through roundabout intersections.

  12. Backup Mechanical Brake System of the Wind Turbine

    Science.gov (United States)

    Sirotkin, E. A.; Solomin, E. V.; Gandzha, S. A.; Kirpichnikova, I. M.

    2018-01-01

    Paper clarifies the necessity of the emergency mechanical brake systems usage for wind turbines. We made a deep analysis of the wind turbine braking methods available on the market, identifying their strengths and weaknesses. The electromechanical braking appeared the most technically reasonable and economically attractive. We described the developed combined electromechanical brake system for vertical axis wind turbine driven from electric drive with variable torque enough to brake over the turbine even on the storm wind speed up to 45 m/s. The progress was made due to the development of specific kinematic brake system diagram and intelligent control system managed by special operation algorithm.

  13. Joint optimization of green vehicle scheduling and routing problem with time-varying speeds

    Science.gov (United States)

    Zhang, Dezhi; Wang, Xin; Ni, Nan; Zhang, Zhuo

    2018-01-01

    Based on an analysis of the congestion effect and changes in the speed of vehicle flow during morning and evening peaks in a large- or medium-sized city, the piecewise function is used to capture the rules of the time-varying speed of vehicles, which are very important in modelling their fuel consumption and CO2 emission. A joint optimization model of the green vehicle scheduling and routing problem with time-varying speeds is presented in this study. Extra wages during nonworking periods and soft time-window constraints are considered. A heuristic algorithm based on the adaptive large neighborhood search algorithm is also presented. Finally, a numerical simulation example is provided to illustrate the optimization model and its algorithm. Results show that, (1) the shortest route is not necessarily the route that consumes the least energy, (2) the departure time influences the vehicle fuel consumption and CO2 emissions and the optimal departure time saves on fuel consumption and reduces CO2 emissions by up to 5.4%, and (3) extra driver wages have significant effects on routing and departure time slot decisions. PMID:29466370

  14. Population distributions of time to collision at brake application during car following from naturalistic driving data.

    Science.gov (United States)

    Kusano, Kristofer D; Chen, Rong; Montgomery, Jade; Gabler, Hampton C

    2015-09-01

    Forward collision warning (FCW) systems are designed to mitigate the effects of rear-end collisions. Driver acceptance of these systems is crucial to their success, as perceived "nuisance" alarms may cause drivers to disable the systems. In order to make customizable FCW thresholds, system designers need to quantify the variation in braking behavior in the driving population. The objective of this study was to quantify the time to collision (TTC) that drivers applied the brakes during car following scenarios from a large scale naturalistic driving study (NDS). Because of the large amount of data generated by NDS, an automated algorithm was developed to identify lead vehicles using radar data recorded as part of the study. Using the search algorithm, all trips from 64 drivers from the 100-Car NDS were analyzed. A comparison of the algorithm to 7135 brake applications where the presence of a lead vehicle was manually identified found that the algorithm agreed with the human review 90.6% of the time. This study examined 72,123 trips that resulted in 2.6 million brake applications. Population distributions of the minimum, 1st, and 10th percentiles were computed for each driver in speed ranges between 3 and 60 mph in 10 mph increments. As speed increased, so did the minimum TTC experience by drivers as well as variance in TTC. Younger drivers (18-30) had lower TTC at brake application compared to older drivers (30-51+), especially at speeds between 40 mph and 60 mph. This is one of the first studies to use large scale NDS data to quantify braking behavior during car following. The results of this study can be used to design and evaluate FCW systems and calibrate traffic simulation models. Copyright © 2015 Elsevier Ltd and National Safety Council. All rights reserved.

  15. Vehicle Speed Determination in Case of Road Accident by Software Method and Comparing of Results with the Mathematical Model

    OpenAIRE

    Hoxha Gezim; Shala Ahmet; Likaj Rame

    2017-01-01

    The paper addresses the problem to vehicle speed calculation at road accidents. To determine the speed are used the PC Crash software and Virtual Crash. With both methods are analysed concrete cases of road accidents. Calculation methods and comparing results are present for analyse. These methods consider several factors such are: the front part of the vehicle, the technical feature of the vehicle, car angle, remote relocation after the crash, road conditions etc. Expected results with PC Cr...

  16. Estimation of Road Vehicle Speed Using Two Omnidirectional Microphones: A Maximum Likelihood Approach

    Directory of Open Access Journals (Sweden)

    López-Valcarce Roberto

    2004-01-01

    Full Text Available We address the problem of estimating the speed of a road vehicle from its acoustic signature, recorded by a pair of omnidirectional microphones located next to the road. This choice of sensors is motivated by their nonintrusive nature as well as low installation and maintenance costs. A novel estimation technique is proposed, which is based on the maximum likelihood principle. It directly estimates car speed without any assumptions on the acoustic signal emitted by the vehicle. This has the advantages of bypassing troublesome intermediate delay estimation steps as well as eliminating the need for an accurate yet general enough acoustic traffic model. An analysis of the estimate for narrowband and broadband sources is provided and verified with computer simulations. The estimation algorithm uses a bank of modified crosscorrelators and therefore it is well suited to DSP implementation, performing well with preliminary field data.

  17. Comparative field evaluation of vehicle cruise speed and acceleration level impacts on hot stabilized emissions

    International Nuclear Information System (INIS)

    El-Shawarby, Ihab; Ahn, Kyoungho; Rakha, Hesham

    2005-01-01

    The main objectives of this paper are two fold. First, the paper evaluates the impact of vehicle cruise speed and acceleration levels on vehicle fuel-consumption and emission rates using field data gathered under real-world driving conditions. Second, it validates the VT-Micro model for the modeling of real-world conditions. Specifically, an on-board emission-measurement device was used to collect emissions of oxides of nitrogen, hydrocarbons, carbon monoxide, and carbon dioxide using a light-duty test vehicle. The analysis demonstrates that vehicle fuel-consumption and emission rates per-unit distance are optimum in the range of 60-90 km/h, with considerable increase outside this optimum range. The study demonstrates that as the level of aggressiveness for acceleration maneuvers increases, the fuel-consumption and emission rates per maneuver decrease because the vehicle spends less time accelerating. However, when emissions are gathered over a sufficiently long fixed distance, fuel-consumption and mobile-source emission rates per-unit distance increase as the level of acceleration increases because of the history effects that accompany rich-mode engine operations. In addition, the paper demonstrates the validity of the VT-Micro framework for modeling steady-state vehicle fuel-consumption and emission behavior. Finally, the research demonstrates that the VT-Micro framework requires further refinement to capture non-steady-state history behavior when the engine operates in rich mode. (Author)

  18. Carbody elastic vibrations of high-speed vehicles caused by bogie hunting instability

    Science.gov (United States)

    Wei, Lai; Zeng, Jing; Chi, Maoru; Wang, Jianbin

    2017-09-01

    In particular locations of the high-speed track, the worn wheel profile matched up with the worn rail profile will lead to an extremely high-conicity wheel-rail contact. Consequently, the bogie hunting instability arises, which further results in the so-called carbody shaking phenomenon. In this paper, the carbody elastic vibrations of a high-speed vehicle in service are firstly introduced. Modal tests are conducted to identity the elastic modes of the carbody. The ride comfort and running safety indices for the tested vehicle are evaluated. The rigid-flexible coupling dynamic model for the high-speed passenger car is then developed by using the FE and MBS coupling approach. The rail profiles in those particular locations are measured and further integrated into the simulation model to reproduce the bogie hunting and carbody elastic vibrations. The effects of wheel and rail wear on the vehicle system response, e.g. wheelset bifurcation graph and carbody vibrations, are studied. Two improvement measures, including the wheel profile modification and rail grinding, are proposed to provide possible solutions. It is found that the wheel-rail contact conicity can be lowered by decreasing wheel flange thickness or grinding rail corner, which is expected to improve the bogie hunting stability under worn rail and worn wheel conditions. The carbody elastic vibrations caused by bogie hunting instability can be further restrained.

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

    International Nuclear Information System (INIS)

    AntolIn, P; Goicolea, J M; Astiz, M A; Alonso, A

    2010-01-01

    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.

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

    Science.gov (United States)

    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.

  1. New Structure Design and Simulation of Brake by Wire System Based on Giant-magnetostrictive Material

    Directory of Open Access Journals (Sweden)

    Changbao CHU

    2014-04-01

    Full Text Available Existing electronic mechanical brake by wire system has several disadvantages. For instance, system actuators are complex, response speed slower, larger vibration noise, etc. This paper discusses a new type brake by wire system based on giant-magnetostrictive material. The new type brake by wire system model was set up under Matlab/Simulink software environment. PID control method was used to control the brake by wire system. Simulation results shows that the new type brake by wire system achieves better braking performance compared with hydraulic braking system. This work provides a new idea for researching automobile brake by wire system.

  2. MODELLING OF DYNAMIC SPEED LIMITS USING THE MODEL PREDICTIVE CONTROL

    Directory of Open Access Journals (Sweden)

    Andrey Borisovich Nikolaev

    2017-09-01

    Full Text Available The article considers the issues of traffic management using intelligent system “Car-Road” (IVHS, which consist of interacting intelligent vehicles (IV and intelligent roadside controllers. Vehicles are organized in convoy with small distances between them. All vehicles are assumed to be fully automated (throttle control, braking, steering. Proposed approaches for determining speed limits for traffic cars on the motorway using a model predictive control (MPC. The article proposes an approach to dynamic speed limit to minimize the downtime of vehicles in traffic.

  3. Optimal design for slip deceleration control in anti-lock braking system

    Science.gov (United States)

    Mishra, Sheelam; Kumar, Pankaj; Rahman, Mohd. Saifur

    2018-05-01

    ABS (Anti-lock Braking System) is the most advanced braking system implemented in modern cars to avoid the slipping or skidding of the vehicle on the road. Moreover, it reduces the stopping distance of the vehicle because it avoids the locking of the wheel during braking. It enables the driver to steer the vehicle during braking. But every system has its downsides and likewise ABS too, it is not efficient during normal braking or snowy conditions. Our aim is to overcome these downsides and optimize Anti-lock Braking System to make it even better.

  4. Influences of pre-crash braking induced dummy - forward displacements on dummy behaviour during EuroNCAP frontal crashtest.

    Science.gov (United States)

    Woitsch, Gernot; Sinz, Wolfgang

    2014-01-01

    Combination of active and passive safety systems is a future key to further improvement in vehicle safety. Autonomous braking systems are able to reduce collision speeds, and therefore severity levels significantly. Passengers change their position due to pre-impact vehicle motion, a fact, which has not yet been considered in common crash tests. For this paper, finite elements simulations of crash tests were performed to show that forward displacements due to pre-crash braking do not necessarily increase dummy load levels. So the influence of different pre-crash scenarios, all leading to equal closing speeds in the crash phase, are considered in terms of vehicle motion (pitching, deceleration) and restraint system configurations (belt load limiter, pretensioner). The influence is evaluated by dummy loads as well as contact risk between the dummy and the interior. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Visual and cognitive predictors of performance on brake reaction test: Salisbury eye evaluation driving study.

    Science.gov (United States)

    Zhang, Lei; Baldwin, Kevin; Munoz, Beatriz; Munro, Cynthia; Turano, Kathleen; Hassan, Shirin; Lyketsos, Constantine; Bandeen-Roche, Karen; West, Sheila K

    2007-01-01

    Concern for driving safety has prompted research into understanding factors related to performance. Brake reaction speed (BRS), the speed with which persons react to a sudden change in driving conditions, is a measure of performance. Our aim is to determine the visual, cognitive, and physical factors predicting BRS in a population sample of 1425 older drivers. The Maryland Department of Motor Vehicles roster of persons aged 67-87 and residing in Salisbury, MD, was used for recruitment of the study population. Procedures included the following: habitual, binocular visual acuity using ETDRS charts, contrast sensitivity using a Pelli-Robson chart, visual fields assessed with a 81-point screening Humphrey field at a single intensity threshold, and a questionnaire to ascertain medical conditions. Cognitive status was assessed using a standard battery of tests for attention, memory, visuo-spatial, and scanning. BRS was assessed using a computer-driven device that measured separately the initial reaction speed (IRS) (from light change to red until removing foot from accelerator) and physical response speed (PRS) (removing foot from accelerator to full brake depression). Five trial times were averaged, and time was converted to speed. The median brake reaction time varied from 384 to 5688 milliseconds. Age, gender, and cognition predicted total BRS, a non-informative result as there are two distinct parts to the task. Once separated, decrease in IRS was associated with low scores on cognitive factors and missing points on the visual field. A decrease in PRS was associated with having three or more physical complaints related to legs and feet, and poorer vision search. Vision was not related to PRS. We have demonstrated the importance of segregating the speeds for the two tasks involved in brake reaction. Only the IRS depends on vision. Persons in good physical condition may perform poorly on brake reaction tests if their vision or cognition is compromised.

  6. Emergency braking : research summary.

    NARCIS (Netherlands)

    Schlösser, L.H.M.

    1976-01-01

    This report deals with an investigation concerning braking capacity of trucks if somewhere a failure occurs in the normal service brake. Purpose of research was to get an insight in various secondary braking systems for trucks. It is shown that with almost all of the secondary braking system it was

  7. ABOUT WAVEFORM OF BRAKING CYLINDER FILLING IN FREIGHT CARS

    Directory of Open Access Journals (Sweden)

    L. V. Ursuliak

    2016-04-01

    Full Text Available Purpose. As part of the scientific paper it is necessary to study the waveform impact of the braking cylinders filling on longitudinal train dynamics at different modes of braking. At this one should estimate the level of maximum longitudinal forces and braking distance size in freight cars of various lengths. Methodology. In this paper we attempt to approximate the actual diagram of braking cylinders filling with rational functions of varying degrees. In selection of coefficients in the required functions the highest values of the longitudinal forces and braking distances were used as controlled parameters. They were compared with similar values obtained as a result of experimental rides. The level of longitudinal forces and braking distances amount were evaluated by means of mathematical modeling of train longitudinal vibrations, caused by different braking modes. Findings. At mathematical modeling was assumed that the train consists of 60 uniform four-axle gondola cars, weight of 80 tons, equipped with air dispenser No. 483 included in the median operation, composite braking blocks, and one locomotive VL-8. Train before braking has been pre-stretched. Various types of pneumatic braking (emergency, full service and adjusting braking of the freight train on the horizontal section of the track were simulated. As the calculation results were obtained values of the longitudinal forces, braking distances amounts and reduction time in speed at various braking modes. Originality. Waveform impact of the braking cylinders filling on the longitudinal forces level and braking distances amount in freight trains were investigated. Also the longitudinal loading of freight trains at various pneumatic braking was investigated. Practical value. Obtained results can be used to assess the level of largest longitudinal forces and braking distances in the freight trains of different lengths by mathematical modeling of different braking modes.

  8. Using endemic road features to create self-explaining roads and reduce vehicle speeds.

    Science.gov (United States)

    Charlton, Samuel G; Mackie, Hamish W; Baas, Peter H; Hay, Karen; Menezes, Miguel; Dixon, Claire

    2010-11-01

    This paper describes a project undertaken to establish a self-explaining roads (SER) design programme on existing streets in an urban area. The methodology focussed on developing a process to identify functional road categories and designs based on endemic road characteristics taken from functional exemplars in the study area. The study area was divided into two sections, one to receive SER treatments designed to maximise visual differences between road categories, and a matched control area to remain untreated for purposes of comparison. The SER design for local roads included increased landscaping and community islands to limit forward visibility, and removal of road markings to create a visually distinct road environment. In comparison, roads categorised as collectors received increased delineation, addition of cycle lanes, and improved amenity for pedestrians. Speed data collected 3 months after implementation showed a significant reduction in vehicle speeds on local roads and increased homogeneity of speeds on both local and collector roads. The objective speed data, combined with residents' speed choice ratings, indicated that the project was successful in creating two discriminably different road categories. 2010 Elsevier Ltd. All rights reserved.

  9. 76 FR 56318 - Parts and Accessories Necessary for Safe Operation; Saddle-Mount Braking Requirements

    Science.gov (United States)

    2011-09-13

    ... because the lightly loaded axle of the last vehicle tends to lock up under heavy braking. DATES: The final... antilock braking systems. ACC Automobile Carriers Conference. ATA American Trucking Associations. ATC ATC... heavy braking, potentially increasing stopping distance. Stopping distances are specified in the vehicle...

  10. Influence of Suspended Equipment on the Carbody Vertical Vibration Behaviour of High-Speed Railway Vehicles

    Directory of Open Access Journals (Sweden)

    Dumitriu Mădălina

    2016-03-01

    Full Text Available The equipment mounted on the carbody chassis of the railway vehicles is a critical component of the vehicle in terms of ride comfort. The reason for that is their large mass, able to visibly influence the vibrations mode of the carbody. The paper examines the influence of the equipment upon the mode of vertical vibrations of the carbody in the high-speed vehicles, reached on the basis of the frequency response functions of the acceleration in three carbody reference points - at the centre and above the bogies. These functions are derived from the numerical simulations developed on a rigid-flexible coupled model, with seven degrees of freedom. As a rule, the results herein prove the influence of the equipment mounting mode (rigid or elastic, along with the speed regime, upon the level of vibrations in the carbody reference points, at the resonance frequency of the symmetrical bending mode. Similarly, it is also demonstrated how the equipment mass and the damping degree of the suspension system affect the level of the vibrations in the carbody.

  11. Ride performance of a high speed rail vehicle using controlled semi active suspension system

    Science.gov (United States)

    Sharma, Sunil Kumar; Kumar, Anil

    2017-05-01

    The rail-wheel interaction in a rail vehicle running at high speed results in large amplitude vibration of carbody that deteriorates the ride comfort of travellers. The role of suspension system is crucial to provide an acceptable level of ride performance. In this context, an existing rail vehicle is modelled in vertical, pitch and roll motions of carbody and bogies. Additionally, nonlinear stiffness and damping parameters of passive suspension system are defined based on experimental data. In the secondary vertical suspension system, a magneto-rheological (MR) damper is included to improve the ride quality and comfort. The parameters of MR damper depend on the current, amplitude and frequency of excitations. At different running speeds, three semi-active suspension strategies with MR damper are analysed for periodic track irregularity and the resulting performance indices are juxtaposed with the nonlinear passive suspension system. The disturbance rejection and force tracking damper controller algorithms are applied to control the desired force of MR damper. This study reveals that the vertical vibrations of a vehicle can be reduced significantly by using the proposed semi-active suspension strategies. Moreover, it naturally results in improved ride quality and passenger’s comfort in comparison to the existing passive system.

  12. Age and gender differences in time to collision at braking from the 100-Car Naturalistic Driving Study.

    Science.gov (United States)

    Montgomery, Jade; Kusano, Kristofer D; Gabler, Hampton C

    2014-01-01

    Forward collision warning (FCW) is an active safety system that aims to mitigate the effect of forward collisions by warning the driver of objects in front of the vehicle. Success of FCW relies on how drivers react to the alerts. Drivers who receive too many warnings that they deem as unnecessary-that is, nuisance alarms-may grow to distrust and turn the system off. To reduce the perception of nuisance alarms, FCW systems can be tailored to individual driving styles, but these driving styles must first be characterized. The objective of this study was to characterize differences in braking behavior between age and gender groups in car-following scenarios using data from the 100-Car Naturalistic Driving Study. The data source for this study was the 100-Car Naturalistic Driving Study, which recorded the driving of 108 primary drivers for approximately a year. Braking behavior was characterized in terms of time to collision (TTC) at brake application, a common metric used in the design of warning thresholds of FCW. Because of the large volume of data analyzed, the TTC at which drivers braked during car-following situations was collected via an automated search algorithm. The minimum TTC for each vehicle speed 10 mph increment from 10 mph to 80 mph was recorded for each driver. Mixed model analysis of variance was used to examine the differences between age and gender groups. In total, 527,861 brake applications contained in 11,503 trips were analyzed. Differences in TTC at braking were statistically significant for age and gender (Pbraking of 2.5±0.8 s, and females age 31-50 (n=6) had the highest average minimum TTC at braking of 6.4±0.9 s. On average, women (n=32) braked at a TTC 1.3 s higher than men (n=52). Age was a statistically significant factor for TTC at braking between participants under 30 (n=42) and participants over 30 (n=42), with the latter braking 1.7 s on average before the former. No statistical significance was found between ages 18-20 (n=15) and

  13. Embedded Vehicle Speed Estimation System Using an Asynchronous Temporal Contrast Vision Sensor

    Directory of Open Access Journals (Sweden)

    D. Bauer

    2007-01-01

    Full Text Available This article presents an embedded multilane traffic data acquisition system based on an asynchronous temporal contrast vision sensor, and algorithms for vehicle speed estimation developed to make efficient use of the asynchronous high-precision timing information delivered by this sensor. The vision sensor features high temporal resolution with a latency of less than 100 μs, wide dynamic range of 120 dB of illumination, and zero-redundancy, asynchronous data output. For data collection, processing and interfacing, a low-cost digital signal processor is used. The speed of the detected vehicles is calculated from the vision sensor's asynchronous temporal contrast event data. We present three different algorithms for velocity estimation and evaluate their accuracy by means of calibrated reference measurements. The error of the speed estimation of all algorithms is near zero mean and has a standard deviation better than 3% for both traffic flow directions. The results and the accuracy limitations as well as the combined use of the algorithms in the system are discussed.

  14. Influence of convective cooling on a disc brake temperature distribution during repetitive braking

    International Nuclear Information System (INIS)

    Adamowicz, Adam; Grzes, Piotr

    2011-01-01

    The purpose of this study is to evaluate an impact of convective mode of heat transfer on the thermal behaviour of a disc brake system during repetitive braking process with the constant velocity using fully three-dimensional finite element model. The transient thermal analysis to determine the temperature distributions on the contact surface of a disc brake is performed. The issue of non-uniform frictional heating effects of mutual slipping of a disc over fixed pads is tested using FE models with the several possible to occur in automotive application heat transfer coefficients. To have a possibility of comparison of the temperature distributions of a disc during cyclic brake application, the energy transformed during time of every analyzed case of braking process and the subsequent release periods was equal. The time-stepping procedure is employed to develop moving heat source as the boundary heat flux acting interchangeably with the convective cooling terms. The difficulties accounted for the accurate simulation of heating during spin of the rotor is omitted by the use of the code, which enable shaping curves responsible for the thermal flux entering the disc at subsequent moments of time. The resulting evolution of temperature on the friction surface reveals a wide range of variations, distinguishing periods of heating and cooling states. It has been established, that during single braking the convective cooling has insignificant influence on the temperature distributions of a disc brake, consequently is not able to prevent overheat problem. However the brake release period after the braking operation, when the velocity of the vehicle remains on the same level, results in considerable decrease of temperature. - Highlights: → Convection does not allow to lower temperature of disc during single braking process. → Maximal temperature of disc decreases with number of brake applications. → Temperature at the end of braking increases with number of brake

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

    Directory of Open Access Journals (Sweden)

    Anne Paul Anthikkat

    2013-01-01

    Full Text Available 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.

  16. The wheel-rail contact friction influence on high speed vehicle model stability

    Directory of Open Access Journals (Sweden)

    Mirosław DUSZA

    2015-09-01

    Full Text Available Right estimating of the coefficient of friction between the wheel and rail is essential in modelling rail vehicle dynamics. Constant value of coefficient of friction is the typical assumption in theoretical studies. But it is obvious that in real circumstances a few factors may have significant influence on the rails surface condition and this way on the coefficient of friction value. For example the weather condition, the railway location etc. Influence of the coefficient of friction changes on high speed rail vehicle model dynamics is presented in this paper. Four axle rail vehicle model were built. The FASTSIM code is employed for calculation of the tangential contact forces between wheel and rail. One coefficient of friction value is adopted in the particular simulation process. To check the vehicle model properties under the influence of wheel-rail coefficient of friction changes, twenty four series of simulations were performed. For three curved tracks of radii R = 3000m, 6000m and  (straight track, the coefficient of friction was changed from 0.1 to 0.8. The results are presented in form of bifurcation diagrams.

  17. A quasi-vehicle/bridge interaction model for high speed railways

    Czech Academy of Sciences Publication Activity Database

    Yau, J. D.; Frýba, Ladislav

    2015-01-01

    Roč. 31, č. 2 (2015), s. 217-225 ISSN 1727-7191 R&D Projects: GA ČR(CZ) GA103/08/1340 Grant - others:National Science Council in Taiwan(TW) NSC 102-2923-E-032-002-MY3 Institutional support: RVO:68378297 Keywords : high speed train * quasi-VBI model * resonance * vehicle-bridge interaction Subject RIV: JM - Building Engineering Impact factor: 0.828, year: 2015 http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9645645&fileId=S1727719114000896

  18. A low cost, light weight cenosphere–aluminium composite for brake ...

    Indian Academy of Sciences (India)

    2. Literature review. Disc brake is often used in automobile transmission system to halt a vehicle. .... components such as brake disc, jet turbines, engines, power plants, etc. ... This section presents an infrared (IR)-based wireless temperature ...

  19. Improved Line Tracking System for Autonomous Navigation of High-Speed Vehicle

    Directory of Open Access Journals (Sweden)

    Yahya Zare Khafri

    2012-07-01

    Full Text Available Line tracking navigation is one of the most widely techniques used in the robot navigation. In this paper, a customized line tracking system is proposed for autonomous navigation of high speed vehicles. In the presented system, auxiliary information -in addition to the road path- is added to the tracking lines such as locations of turn and intersections in the real roads. Moreover, the geometric position of line sensors is re-designed enables the high rate sensing with higher reliability. Finally, a light-weight navigation algorithm is proposed allow the high-speed movement using a reasonable processing power. This system is implemented on a MIPS-based embedded processor and experimental results with this embedded system show more than 98% accuracy at 200km/h with a 1GHz processor is viable.

  20. Issues Relative to the Control of Large High Speed Unmanned Vehicles for Use in Crash Rescue Operations. A Technical Paper Presented to the American Nuclear Society, Ninth International Topical Meeting on Robotics and Remote Systems Held in Seattle, WA on March 4-8, 2001

    National Research Council Canada - National Science Library

    English, Ralph

    2000-01-01

    .... The control systems of small, slow moving machines common in research and development platforms have historically ignored vehicle dynamics beyond basic parameters such as acceleration, steering and braking...

  1. Vehicle Speed Determination in Case of Road Accident by Software Method and Comparing of Results with the Mathematical Model

    Directory of Open Access Journals (Sweden)

    Hoxha Gezim

    2017-11-01

    Full Text Available The paper addresses the problem to vehicle speed calculation at road accidents. To determine the speed are used the PC Crash software and Virtual Crash. With both methods are analysed concrete cases of road accidents. Calculation methods and comparing results are present for analyse. These methods consider several factors such are: the front part of the vehicle, the technical feature of the vehicle, car angle, remote relocation after the crash, road conditions etc. Expected results with PC Crash software and Virtual Crash are shown in tabular graphics and compared in mathematical methods.

  2. Modelling and design optimization of low speed fuel cell - battery hybrid electric vehicles. Paper no. IGEC-1-125

    International Nuclear Information System (INIS)

    Guenther, M.; Dong, Z.

    2005-01-01

    A push for electric vehicles has occurred in the past several decades due to various concerns about air pollution and the contribution of emissions to global climate change. Although electric cars and buses have been the focus of much of electric vehicle development, smaller vehicles are used extensively for transportation and utility purposes in many countries. In order to explore the viability of fuel cell - battery hybrid electric vehicles, empirical fuel cell system data has been incorporated into the NREL's vehicle design and simulation tool, ADVISOR (ADvanced Vehicle SimulatOR), to predict the performance of a low-speed, fuel cell - battery electric vehicle through MATLAB Simulink. The modelling and simulation provide valuable feedback to the design optimization of the fuel cell power system. A sampling based optimization algorithm was used to explore the viability and options of a low cost design for urban use. (author)

  3. Effect of gas release in hot molding on flexural strength of composite friction brake

    Science.gov (United States)

    Rusdja, Andy Permana; Surojo, Eko; Muhayat, Nurul; Raharjo, Wijang Wisnu

    2018-02-01

    Composite friction brake is a vital part of braking system which serves to reduce the speed of vehicle. To fulfill the requirement of brake performance, composite friction brake must have friction and mechanical characteristic as required. The characteristics of composite friction brake are affected by brake material formulation and manufacturing parameter. In the beginning of hot molding, intermittent hot pressing was carried out to release the gases that consist of ammonia gas and water vapor. In composite friction brake, phenolic resin containing hexamethylenetetramine (HMTA) is often used as a binder. During hot molding, the reaction of phenolic resin and HMTA forms ammonia gas. Hot molding also generates water vapor because raw materials absorb moisture from environment when they are placed in storage. The gas release in hot molding is supposed affecting mechanical properties because it avoid entrapped gas in composite, so that this research investigated effect of gas release on flexural strength. Manufacturing of composite specimen was carried out as follow: mixing of raw materials, cold molding, and hot molding. In this research, duration of intermittent hot pressing and number of gas release were varied. The flexural strength of specimen was measured using three point bending test. The results showed that flexural strength specimens that were manufactured without gas release, using 4 times gas release with intermittent hot pressing for 5 and 10 seconds were not remarkably different. Conversely, hot molding using 4 times gas release with intermittent hot pressing for 15 seconds decreased flexural strength of composite. Hot molding using 2, 4, and 8 times gas release with intermittent hot pressing for 10 seconds also had no effect on increasing flexural strength. Increasing of flexural strength of composite was obtained only by using 6 times gas release with intermittent hot pressing for 10 seconds.

  4. 14 CFR 25.735 - Brakes and braking systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Brakes and braking systems. 25.735 Section... braking systems. (a) Approval. Each assembly consisting of a wheel(s) and brake(s) must be approved. (b... an automatic braking system is installed, means are provided to: (i) Arm and disarm the system, and...

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

    Science.gov (United States)

    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.

  6. Implementation and Performance Evaluation of a Regenerative Braking System Coupled to Ultracapacitors for a Brushless DC Hub Motor Driven Electric Tricycle

    OpenAIRE

    Kuruppu, Sandun

    2010-01-01

    Research related to electrical vehicles is gaining importance due to the, energy crisis. An electric vehicle itself is far ahead of an internal combustion, engine based vehicle due to its efficiency. Using regenerative braking when, braking, improves the efficiency of an electric vehicle as it recovers energy that, could go to waste if mechanical brakes were used. A novel regenerative braking, system for neighborhood electric vehicles was designed, prototyped and tested., The proposed system ...

  7. Real-Time Vehicle Speed Estimation Based on License Plate Tracking in Monocular Video Sequences

    Directory of Open Access Journals (Sweden)

    Aleksej MAKAROV

    2016-02-01

    Full Text Available A method of estimating the vehicle speed from images obtained by a fixed over-the-road monocular camera is presented. The method is based on detecting and tracking vehicle license plates. The contrast between the license plate and its surroundings is enhanced using infrared light emitting diodes and infrared camera filters. A range of the license plate height values is assumed a priori. The camera vertical angle of view is measured prior to installation. The camera tilt is continuously measured by a micro-electromechanical sensor. The distance of the license plate from the camera is theoretically derived in terms of its pixel coordinates. Inaccuracies due to the frame rate drift, to the tilt and the angle of view measurement errors, to edge pixel detection and to a coarse assumption of the vehicle license plate height are analyzed and theoretically formulated. The resulting system is computationally efficient, inexpensive and easy to install and maintain along with the existing ALPR cameras.

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

    Science.gov (United States)

    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.

  9. Antiskid braking system

    Science.gov (United States)

    Pazdera, J. S.

    1974-01-01

    Published report describes analytical development and simulation of braking system. System prevents wheels from skidding when brakes are applied, significantly reducing stopping distance. Report also presents computer simulation study on system as applied to aircraft.

  10. Mobile robot vehicles for physical security

    International Nuclear Information System (INIS)

    McGovern, D.E.

    1987-07-01

    A fleet of vehicles is being developed and maintained by Sandia National Labs for studies in remote control and autonomous operation. These vehicles range from modified commercial vehicles to specially constructed mobile platforms and are utilized as test beds for developing concepts in the application of robotics to interior and exterior physical security. Actuators control the vehicle speed, brakes, and steering through manual input from a remote driving station or through some level of digital computer control. On-board processing may include simple vehicle control functions or may allow for unmanned, autonomous operation. communication links are provided for digital communication between control computers, television transmission for vehicle vision, and voice for local control. With these vehicles, SNL can develop, test, and evaluate sensors, processing requirements, various methods of actuator implementation, operator controlled feedback requirements, and vehicle operations. A description of the major features and uses for each of the vehicles in the fleet is provided

  11. Mobile robot vehicles for physical security

    International Nuclear Information System (INIS)

    Mc Govern, D.E.

    1987-01-01

    A fleet of vehicles is being developed and maintained by Sandia National Labs for studies in remote control and autonomous operation. These vehicles range from modified commercial vehicles to specially constructed mobile platforms and are utilized as test beds for developing concepts in the application of robotics to interior and exterior physical security. Actuators control the vehicle speed, brakes, and steering through manual input from a remote driving station or through some level of digital computer control. On-board processing may include simple vehicle control functions or may allow for unmanned, autonomous operation. Communication links are provided for digital communication between control computers, television transmission for vehicle vision, and voice for local control. With these vehicles, SNL can develop, test, and evaluate sensors, processing requirements, various methods of actuator implementation, operator controlled feedback requirements, and vehicle operations. A description of the major features and uses for each of the vehicles in the fleet is provided

  12. Mobile robot vehicles for physical security

    International Nuclear Information System (INIS)

    McGovern, D.E.

    1987-06-01

    A fleet of vehicles is being developed and maintained by Sandia National Labs for studies in remote control and autonomous operation. These vehicles range from modified commercial vehicles to specially constructed mobile platforms and are utilized as test beds for developing concepts in the application of robotics to interior and exterior physical security. Actuators control the vehicle speed, brakes, and steering through manual input from a remote driving station or through some level of digital computer control. On-board processing may include simple vehicle control functions or may allow for unmanned, autonomous operation. Communication links are provided for digital communication between control computers, television transmission for vehicle vision, and voice for local control. With these vehicles, SNL can develop, test, and evaluate sensors, processing requirements, various methods of actuator implementation, operator controlled feedback requirements, and vehicle operations. A description of the major features and uses for each of the vehicles in the fleet is provided. 4 refs., 1 fig., 1 tab

  13. The antilock braking system anomaly: a drinking driver problem?

    Science.gov (United States)

    Harless, David W; Hoffer, George E

    2002-05-01

    Antilock braking systems (ABS) have held promise for reducing the incidence of accidents because they reduce stopping times on slippery surfaces and allow drivers to maintain steering control during emergency braking. Farmer et al. (Accident Anal. Prevent. 29 (1997) 745) provide evidence that antilock brakes are beneficial to nonoccupants: a set of 1992 model General Motors vehicles equipped with antilock brakes were involved in significantly fewer fatal crashes in which occupants of other vehicles, pedestrians, or bicyclists were killed. But, perversely, the risk of death for occupants of vehicles equipped with antilock brakes increased significantly after adoption. Farmer (Accident Anal. Prevent. 33 (2001) 361) updates the analysis for 1996- 1998 and finds a significant attenuation in the ABS anomaly. Researchers have put forward two hypotheses to explain this antilock brake anomaly: risk compensation and improper operation of antilock brake-equipped vehicles. We provide strong evidence for the improper operation hypothesis by showing that the antilock brake anomaly is confined largely to drinking drivers. Further, we show that the attenuation phenomenon occurs consistently after the first three to four years of vehicle service.

  14. Deployable Brake for Spacecraft

    Science.gov (United States)

    Rausch, J. R.; Maloney, J. W.

    1987-01-01

    Aerodynamic shield that could be opened and closed proposed. Report presents concepts for deployable aerodynamic brake. Brake used by spacecraft returning from high orbit to low orbit around Earth. Spacecraft makes grazing passes through atmosphere to slow down by drag of brake. Brake flexible shield made of woven metal or ceramic withstanding high temperatures created by air friction. Stored until needed, then deployed by set of struts.

  15. Brake reactions of distracted drivers to pedestrian Forward Collision Warning systems.

    Science.gov (United States)

    Lubbe, Nils

    2017-06-01

    Forward Collision Warning (FCW) can be effective in directing driver attention towards a conflict and thereby aid in preventing or mitigating collisions. FCW systems aiming at pedestrian protection have been introduced onto the market, yet an assessment of their safety benefits depends on the accurate modeling of driver reactions when the system is activated. This study contributes by quantifying brake reaction time and brake behavior (deceleration levels and jerk) to compare the effectiveness of an audio-visual warning only, an added haptic brake pulse warning, and an added Head-Up Display in reducing the frequency of collisions with pedestrians. Further, this study provides a detailed data set suited for the design of assessment methods for car-to-pedestrian FCW systems. Brake response characteristics were measured for heavily distracted drivers who were subjected to a single FCW event in a high-fidelity driving simulator. The drivers maintained a self-regulated speed of 30km/h in an urban area, with gaze direction diverted from the forward roadway by a secondary task. Collision rates and brake reaction times differed significantly across FCW settings. Brake pulse warnings resulted in the lowest number of collisions and the shortest brake reaction times (mean 0.8s, SD 0.29s). Brake jerk and deceleration were independent of warning type. Ninety percent of drivers exceeded a maximum deceleration of 3.6m/s 2 and a jerk of 5.3m/s 3 . Brake pulse warning was the most effective FCW interface for preventing collisions. In addition, this study presents the data required for driver modeling for car-to-pedestrian FCW similar to Euro NCAP's 2015 car-to-car FCW assessment. Practical applications: Vehicle manufacturers should consider the introduction of brake pulse warnings to their FCW systems. Euro NCAP could introduce an assessment that quantifies the safety benefits of pedestrian FCW systems and thereby aid the proliferation of effective systems. Copyright © 2017

  16. SPEED ROLLER STAND MEASUREMENT SYSTEM CHECKING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Y. Zybtsev

    2011-01-01

    Full Text Available The study has shown that the accuracy of brakes checking by inertial stands depends upon the applied methods of measurement of braking parameters (stand slowing down, braking distance, brakes triggering time, current speed as well as the methods of metrological checking of measuring system canals.

  17. Speed

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Speed. The rate of information transferred per second is the speed of the information. Measured in bits per second. Need for speed on the net: You-Tube phenomenon; IPTV; 3D Video telephony. Online gaming; HDTV.

  18. Roller Locking Brake

    Science.gov (United States)

    Vranish, John M.

    1993-01-01

    Roller locking brake is normally braking rotary mechanism allowing free rotation when electromagnet in mechanism energized. Well suited to robots and other machinery which automatic braking upon removal of electrical power required. More compact and reliable. Requires little electrical power to maintain free rotation and exhibits minimal buildup of heat.

  19. The Legal Status of Low Speed, Electric, Automated Vehicles in Texas : Policy Brief

    Science.gov (United States)

    2018-01-01

    This report explores whether vehicles that are both Neighborhood Electric Vehicles (NEVs) and Automated Vehicles (AVs) may operate legally on public roads in Texas. First is an examination of Neighborhood Electric Vehicles and how they are governed i...

  20. Modeling vehicle operating speed on urban roads in Montreal: a panel mixed ordered probit fractional split model.

    Science.gov (United States)

    Eluru, Naveen; Chakour, Vincent; Chamberlain, Morgan; Miranda-Moreno, Luis F

    2013-10-01

    Vehicle operating speed measured on roadways is a critical component for a host of analysis in the transportation field including transportation safety, traffic flow modeling, roadway geometric design, vehicle emissions modeling, and road user route decisions. The current research effort contributes to the literature on examining vehicle speed on urban roads methodologically and substantively. In terms of methodology, we formulate a new econometric model framework for examining speed profiles. The proposed model is an ordered response formulation of a fractional split model. The ordered nature of the speed variable allows us to propose an ordered variant of the fractional split model in the literature. The proposed formulation allows us to model the proportion of vehicles traveling in each speed interval for the entire segment of roadway. We extend the model to allow the influence of exogenous variables to vary across the population. Further, we develop a panel mixed version of the fractional split model to account for the influence of site-specific unobserved effects. The paper contributes substantively by estimating the proposed model using a unique dataset from Montreal consisting of weekly speed data (collected in hourly intervals) for about 50 local roads and 70 arterial roads. We estimate separate models for local roads and arterial roads. The model estimation exercise considers a whole host of variables including geometric design attributes, roadway attributes, traffic characteristics and environmental factors. The model results highlight the role of various street characteristics including number of lanes, presence of parking, presence of sidewalks, vertical grade, and bicycle route on vehicle speed proportions. The results also highlight the presence of site-specific unobserved effects influencing the speed distribution. The parameters from the modeling exercise are validated using a hold-out sample not considered for model estimation. The results indicate

  1. Dynamic analysis of three autoventilated disc brakes

    Directory of Open Access Journals (Sweden)

    Ricardo A. García-León

    2017-09-01

    Full Text Available The braking system of a car must meet several requirements, among which safety is the most important. It is also composed of a set of mechanical parts such as springs, different types of materials (Metallic and Non Metallic, gases and liquids. The brakes must work safely and predictably in all circumstances, which means having a stable level of friction, in any condition of temperature, humidity and salinity of the environment. For a correct design and operation of brake discs, it is necessary to consider different aspects, such as geometry, type of material, mechanical strength, maximum temperature, thermal deformation, cracking resistance, among others. Therefore, the main objective of this work is to analyze the dynamics and kinetics of the brake system from the pedal as the beginning of mathematical calculations to simulate the behavior and Analysis of Finite Elements (FEA, with the help of SolidWorks Simulation Software. The results show that the third brake disc works best in relation to the other two discs in their different working conditions such as speed and displacement in braking, concluding that depending on the geometry of the brake and the cooling channels these systems can be optimized that are of great importance for the automotive industry.

  2. SYSTEM FOR AUTOMATIC SELECTION OF THE SPEED RATE OF ELECTRIC VEHICLES FOR REDUCING THE POWER CONSUMPTION

    Directory of Open Access Journals (Sweden)

    K. O. Soroka

    2017-06-01

    Full Text Available Purpose. The work is aimed to design a system for automatic selection of the optimal traffic modes and automatic monitoring of the electric energy consumption by electric transport. This automatic system should provide for the minimum energy expenses. Methodology. Current methodologies: 1 mathematical modeling of traffic modes of ground electric vehicles; 2 comparison of modelling results with the statistical monitoring; 3 system development for automatic choice of traffic modes of electric transport with minimal electrical energy consumptions taking into account the given route schedules and the limitations imposed by the general traffic rules. Findings. The authors obtained a mathematical dependency of the energy consumption by electric transport enterprises on the monthly averaged environment temperature was obtained. A system which allows for an automatic selection of the speed limit and provides automatic monitoring of the electrical energy consumption by electric vehicles was proposed in the form of local network, which works together with existing GPS system. Originality. A mathematical model for calculating the motion curves and energy consumption of electric vehicles has been developed. This model takes into account the characteristic values of the motor engine and the steering system, the change of the mass when loading or unloading passengers, the slopes and radii of the roads, the limitations given by the general traffic rules, and other factors. The dependency of the energy consumption on the averaged monthly environment temperature for public electric transport companies has been calculated. Practical value. The developed mathematical model simplifies the calculations of the traffic dynamics and energy consumption. It can be used for calculating the routing maps, for design and upgrade of the power networks, for development of the electricity saving measures. The system simplifies the work of the vehicle driver and allows reducing

  3. Investigation on a Power Coupling Steering System for Dual-Motor Drive Tracked Vehicles Based on Speed Control

    Directory of Open Access Journals (Sweden)

    Li Zhai

    2017-08-01

    Full Text Available Double-motor drive tracked vehicles (2MDTV are widely used in the tracked vehicle industry due to the development of electric vehicle drive systems. The aim of this paper is to solve the problem of insufficient propulsion motor torque in low-speed, small-radius steering and insufficient power in high-speed large-radius steering. In order to do this a new type of steering system with a coupling device is designed and a closed-loop control strategy based on speed is adopted to improve the lateral stability of the vehicle. The work done entails modeling and simulating the 2MDTV and the proposed control strategy in RecurDyn and Matlab/Simulink. The simulation results show that the 2MDTV with the coupling device outputs more torque and power in both steering cases compared to the 2MDTV without the coupling device, and the steering stability of the vehicle is improved by using the strategy based on speed.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Planning of speed profiles for vehicles with automatic drive; Planung von Geschwindigkeitsprofilen fuer automatisch gefuehrte Fahrzeuge

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, O.

    2005-07-01

    Based upon the calculation of US authorities 97% of all accidents are caused by mistakes of the driver. Due to this fact one of the major focuses of research activities of the automobile industry was put on the development of new assistance systems for the driver. These technologies indicate potential risks to the driver and support him with decisions in terms of the actual driving behaviour in dangerous situations. This work presents a new system that provides prospective information in real time about the course of the road lying ahead of the vehicle. Based on this data the driver's assistance system will provide a prognosis on the force working on the vehicle and then propose a suitable speed strategy that guarantees a safe drive at any time (orig.) [German] Nach Berechnungen von US Behoerden sind 97% aller Unfaelle auf Fehlverhalten seitens des Fahrers zurueckzufuehren. Angesichts dieser Tatsache lag in den letzten Jahren einer der wesentlichen Schwerpunkte der Forschungsaktivitaeten der Automobilindustrie in der Entwicklung neuer Fahrerassistenzsysteme. Diese Technologien weisen den Fahrer auf potentielle Gefahren hin und unterstuetzen ihn bei der Entscheidung hinsichtlich des aktuellen Fahrverhaltens in gefaehrlichen Situationen. In der vorliegenden Arbeit wird ein neuartiges Verfahren vorgestellt, welches vorausschauend Informationen ueber den vor dem Fahrzeug zu erwartenden Fahrbahnverlauf in Echtzeit bereitstellt. Basierend auf diesen Daten wird vom Fahrerassistenzsystem eine Prognose ueber die auf das Fahrzeug wirkende Kraft erstellt und anschliessend eine geeignete Geschwindigkeitsstrategie vorgeschlagen, die ein sicheres Durchfahren der Kurve zu jedem Zeitpunkt gewaehrleistet. (orig.)

  6. Automated visual inspection of brake shoe wear

    Science.gov (United States)

    Lu, Shengfang; Liu, Zhen; Nan, Guo; Zhang, Guangjun

    2015-10-01

    With the rapid development of high-speed railway, the automated fault inspection is necessary to ensure train's operation safety. Visual technology is paid more attention in trouble detection and maintenance. For a linear CCD camera, Image alignment is the first step in fault detection. To increase the speed of image processing, an improved scale invariant feature transform (SIFT) method is presented. The image is divided into multiple levels of different resolution. Then, we do not stop to extract the feature from the lowest resolution to the highest level until we get sufficient SIFT key points. At that level, the image is registered and aligned quickly. In the stage of inspection, we devote our efforts to finding the trouble of brake shoe, which is one of the key components in brake system on electrical multiple units train (EMU). Its pre-warning on wear limitation is very important in fault detection. In this paper, we propose an automatic inspection approach to detect the fault of brake shoe. Firstly, we use multi-resolution pyramid template matching technology to fast locate the brake shoe. Then, we employ Hough transform to detect the circles of bolts in brake region. Due to the rigid characteristic of structure, we can identify whether the brake shoe has a fault. The experiments demonstrate that the way we propose has a good performance, and can meet the need of practical applications.

  7. Study on reduction method of brake squeal; Brake naki teigen shuho ni kansuru kento

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, T; Okada, Y [Aisin Seiki Co. Ltd., Aichi (Japan)

    1997-10-01

    The reduction of brake squeal is an important technological subject in terms of making vehicles quieter. In our research, we carried out a modal analysis from the caliper to the installation bracket during generating brake squeal to identify the places that influence the squeal. Based on this, we studied proposals to reduce the squeal, and have reduced the squeal noise at about 5 kHz as reported in this paper. 1 ref., 12 figs.

  8. Parameters Design for a Parallel Hybrid Electric Bus Using Regenerative Brake Model

    Directory of Open Access Journals (Sweden)

    Zilin Ma

    2014-01-01

    Full Text Available A design methodology which uses the regenerative brake model is introduced to determine the major system parameters of a parallel electric hybrid bus drive train. Hybrid system parameters mainly include the power rating of internal combustion engine (ICE, gear ratios of transmission, power rating, and maximal torque of motor, power, and capacity of battery. The regenerative model is built in the vehicle model to estimate the regenerative energy in the real road conditions. The design target is to ensure that the vehicle meets the specified vehicle performance, such as speed and acceleration, and at the same time, operates the ICE within an expected speed range. Several pairs of parameters are selected from the result analysis, and the fuel saving result in the road test shows that a 25% reduction is achieved in fuel consumption.

  9. Analysis and Design of a Speed and Position System for Maglev Vehicles

    Directory of Open Access Journals (Sweden)

    Zhiqiang Long

    2012-06-01

    Full Text Available 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.

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

    Science.gov (United States)

    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.

  11. Fuzzy logic speed control for the engine of an air-powered vehicle

    Directory of Open Access Journals (Sweden)

    Qihui Yu

    2016-03-01

    Full Text Available To improve the condition of air and eliminate exhaust gas pollution, this article proposes a compressed air power system. Instead of an internal combustion engine, the automobile is equipped with a compressed air engine, which transforms the energy of compressed air into mechanical motion energy. A prototype was built, and the compressed air engine was tested on an experimental platform. The output torque and energy efficiency were obtained from experimental results. When the supply pressure was set at 2 MPa and the speed was 420 r min−1, the output torque, the output power, and the energy efficiency were 56 N m, 1.93 kW, and 25%, respectively. To improve the efficiency of the system, a fuzzy logic speed control strategy is proposed and simulated. The experimental study verified that the theoretical evaluation of the system was reasonable, and this research can be referred to as the design and control of air-powered vehicles.

  12. Clutches and brakes design and selection

    CERN Document Server

    Orthwein, William C

    2004-01-01

    Conveniently gathering formulas, analytical methods, and graphs for the design and selection of a wide variety of brakes and clutches in the automotive, aircraft, farming, and manufacturing industries, Clutches and Brakes: Design and Selection, Second Edition simplifies calculations, acquaints engineers with an expansive range of application, and assists in the selection of parameters for specific design challenges. Contains an abundance of examples, 550 display equations, and more than 200 figures for clear presentation of various design strategies Thoroughly revised throughout, the second edition offers… Additional chapters on friction drives and fluid clutches and retarders An extended discussion on cone brakes and clutches A simpler formulation of the torque from a centrifugal clutch Updated sections on automatic braking systems An analysis of variable-speed friction drives with clutch capability Analytical and computer-assisted design techniques.

  13. Advanced technology mobile robotics vehicle fleet

    International Nuclear Information System (INIS)

    McGovern, D.E.

    1987-03-01

    A fleet of vehicles is being developed and maintained by Sandia National Laboratories for studies in remote control and autonomous operation. The vehicles range from modified commercial vehicles to specially constructed mobile platforms and are utilized as testbeds for developing concepts in the areas of remote control (teleoperation) and computer control (autonomy). Actuators control the vehicle speed, brakes, and steering via manual input from a remote driving station or through some level of digital computer control. On-board processing may include simple vehicle control functions or may allow for unmanned, autonomous operation. Communication links are provided for digital communication between control computers, television transmission for vehicle vision, and voice for local control. SNL can develop, test, and evaluate sensors, processing requirements, various methods of actuator implementation, operator controlled feedback requirements, and vehicle operations. A description of the major features and uses for each of the vehicles in the fleet is provided

  14. Parameter design and performance analysis of shift actuator for a two-speed automatic mechanical transmission for pure electric vehicles

    Directory of Open Access Journals (Sweden)

    Jianjun Hu

    2016-08-01

    Full Text Available Recent developments of pure electric vehicles have shown that pure electric vehicles equipped with two-speed or multi-speed gearbox possess higher energy efficiency by ensuring the drive motor operates at its peak performance range. This article presents the design, analysis, and control of a two-speed automatic mechanical transmission for pure electric vehicles. The shift actuator is based on a motor-controlled camshaft where a special geometric groove is machined, and the camshaft realizes the axial positions of the synchronizer sleeve for gear engaging, disengaging, and speed control of the drive motor. Based on the force analysis of shift process, the parameters of shift actuator and shift motor are designed. The drive motor’s torque control strategy before shifting, speed governing control strategy before engaging, shift actuator’s control strategy during gear engaging, and drive motor’s torque recovery strategy after shift process are proposed and implemented with a prototype. To validate the performance of the two-speed gearbox, a test bed was developed based on dSPACE that emulates various operation conditions. The experimental results indicate that the shift process with the proposed shift actuator and control strategy could be accomplished within 1 s under various operation conditions, with shift smoothness up to passenger car standard.

  15. 49 CFR 214.529 - In-service failure of primary braking system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway maintenance...

  16. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Science.gov (United States)

    2010-10-01

    ... brake actuating forces in response to signals from one or more sensed wheels. Initial brake temperature means the average temperature of the service brakes on the hottest axle of the vehicle 0.2 mi before any... procedures and in the sequence set forth in S7. Each school bus with a GVWR greater than 10,000 pounds must...

  17. Driver Behavioral Changes through Interactions with an Automatic Brake System for Collision Avoidance

    Science.gov (United States)

    Itoh, Makoto; Fujiwara, Yusuke; Inagaki, Toshiyuki

    This paper discusses driver's behavioral changes as a result of driver's use of an automatic brake system for preventing a rear-end collision from occurring. Three types of automatic brake systems are investigated in this study. Type 1 brake system applies a strong automatic brake when a collision is very imminent. Type 2 brake system initiates brake operation softly when a rear-end crash may be anticipated. Types 1 and 2 are for avoidance of a collision. Type 3 brake system, on the other hand, applies a strong automatic brake to reduce the damage when a collision can not be avoided. An experiment was conducted with a driving simulator in order to analyze the driver's possible behavioral changes. The results showed that the time headway (THW) during car following phase was reduced by use of an automatic brake system of any type. The inverse of time to collision (TTC), which is an index of the driver's brake timing, increased by use of Type 1 brake system when the deceleration rate of the lead vehicle was relatively low. However, the brake timing did not change when the drivers used Type 2 or 3 brake system. As a whole, dangerous behavioral changes, such as overreliance on a brake system, were not observed for either type of brake system.

  18. A nonlinear model predictive control formulation for obstacle avoidance in high-speed autonomous ground vehicles in unstructured environments

    Science.gov (United States)

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

    2018-06-01

    This paper presents a nonlinear model predictive control (MPC) formulation for obstacle avoidance in high-speed, large-size autono-mous ground vehicles (AGVs) with high centre of gravity (CoG) that operate in unstructured environments, such as military vehicles. The term 'unstructured' in this context denotes that there are no lanes or traffic rules to follow. Existing MPC formulations for passenger vehicles in structured environments do not readily apply to this context. Thus, a new nonlinear MPC formulation is developed to navigate an AGV from its initial position to a target position at high-speed safely. First, a new cost function formulation is used that aims to find the shortest path to the target position, since no reference trajectory exists in unstructured environments. Second, a region partitioning approach is used in conjunction with a multi-phase optimal control formulation to accommodate the complicated forms the obstacle-free region can assume due to the presence of multiple obstacles in the prediction horizon in an unstructured environment. Third, the no-wheel-lift-off condition, which is the major dynamical safety concern for high-speed, high-CoG AGVs, is ensured by limiting the steering angle within a range obtained offline using a 14 degrees-of-freedom vehicle dynamics model. Thus, a safe, high-speed navigation is enabled in an unstructured environment. Simulations of an AGV approaching multiple obstacles are provided to demonstrate the effectiveness of the algorithm.

  19. Brake Fundamentals. Automotive Articulation Project.

    Science.gov (United States)

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

  20. CFD Modeling and Simulation of Aeorodynamic Cooling of Automotive Brake Rotor

    Science.gov (United States)

    Belhocien, Ali; Omar, Wan Zaidi Wan

    Braking system is one of the important control systems of an automotive. For many years, the disc brakes have been used in automobiles for the safe retarding of the vehicles. During the braking enormous amount of heat will be generated and for effective braking sufficient heat dissipation is essential. The thermal performance of disc brake depends upon the characteristics of the airflow around the brake rotor and hence the aerodynamics is an important in the region of brake components. A CFD analysis is carried out on the braking system as a case study to make out the behavior of airflow distribution around the disc brake components using ANSYS CFX software. We are interested in the determination of the heat transfer coefficient (HTC) on each surface of a ventilated disc rotor varying with time in a transient state using CFD analysis, and then imported the surface film condition data into a corresponding FEM model for disc temperature analysis.

  1. Vehicle safety telemetry for automated highways

    Science.gov (United States)

    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.

  2. Antilock braking system effectiveness in prevention of road traffic crashes in Iran.

    Science.gov (United States)

    Khorasani-Zavareh, Davoud; Shoar, Saeed; Saadat, Soheil

    2013-05-04

    Anti-lock Brake System (ABS) helps the equipped vehicles to stop under heavy braking, in a shorter distance and with a better control of direction. It was expected that this technology will reduce the rate of fatal road traffic crashes (RTC); however, the outcome is controversial in the real world. The aim of this study is to compare the claimed annual incidence rate and financial losses due to RTCs in ABS vs. non-ABS personal vehicles in Iran. A telephone survey among drivers of two similar models of personal vehicles was arranged. The studied vehicles were of the same brand and type; but only one of them was equipped with ABS. The number of RTCs, subsequent financial loss, and drivers' knowledge and perception about ABS were sought. The sample consisted of drivers of 1232 ABS and 3123 non-ABS vehicles. The annual incidence rate of RTC involving another vehicle was 145.1 (134.8-155.9) per 1000 vehicle-years and there was not a statistically significant difference between study groups.The incidence of RTC with another vehicle due to brake failure was 50.3 (42.9-58.5) for 1000 non ABS vehicle-years and 30.0 (21.2-41.2) for 1000 ABS equipped vehicle-years. The difference was statistically significant after adjustment for the driver and vehicle's age and the daily driving time. The attributable risk of RTC for non-ABS vehicles was 20/1000 vehicles and the excess fraction was 39.8%. The mean financial loss due to reported RTCs was $987.9 ± $1547.3 US Dollars and there was not a statistically significant difference between study groups. While 61.1% of ABS vehicle drivers reported situations in which they believed the ABS had prevented a crash, 44.1% of them however, they did not know how to use ABS efficiently. Law enforcement to maintain safe distance and adhere to speed limit while driving, is needed to raise the effectiveness of ABS. This is as necessary as considering mandatory outfitting of ABS. Safety authorities should first consider the global experience

  3. Usage of aids monitoring in automatic braking systems of modern cars

    OpenAIRE

    Dembitskyi V.; Mazylyuk P.; Sitovskyi O.

    2016-01-01

    Increased safety can be carried out at the expense the installation on vehicles of automatic braking systems, that monitor the traffic situation and the actions of the driver. In this paper considered the advantages and disadvantages of automatic braking systems, were analyzed modern tracking tools that are used in automatic braking systems. Based on the statistical data on accidents, are set the main dangers, that the automatic braking system will be reduced. In order to ensure the acc...

  4. Nonlinear Adaptive Rotational Speed Control Design and Experiment of the Propeller of an Electric Micro Air Vehicle

    Directory of Open Access Journals (Sweden)

    Shouzhao Sheng

    2016-01-01

    Full Text Available Micro Air Vehicles (MAVs driven by electric propellers are of interest for military and civilian applications. The rotational speed control of such electric propellers is an important factor for improving the flight performance of the vehicles, such as their positioning accuracy and stability. Therefore, this paper presents a nonlinear adaptive control scheme for the electric propulsion system of a certain MAV, which can not only speed up the convergence rates of adjustable parameters, but can also ensure the overall stability of the adjustable parameters. The significant improvement of the dynamic tracking accuracy of the rotational speed can be easily achieved through the combination of the proposed control algorithm and linear control methods. The experimental test results have also demonstrated the positive effect of the nonlinear adaptive control scheme on the flight performance of the MAV.

  5. Reel safety brake

    Science.gov (United States)

    Carle, C. E. (Inventor)

    1976-01-01

    A braking apparatus is described for a tape transport device having two stacked coaxial reels and feelers mounted in proximity to the reels for sensing the tape being wound on each reel. A device is mounted in proximity to adjacent central hubs of the reels to a simultaneously, frictionally engage both hubs and brake both reels. A mechanical actuator is coupled to both feelers and to the brake device. The brake means comprises a pair of rubber shoulders that extend in opposite directions relative to a common axis, and turns about the axis in response to either of the feelers.

  6. Market penetration speed and effects on CO2 reduction of electric vehicles and plug-in hybrid electric vehicles in Japan

    International Nuclear Information System (INIS)

    Yabe, Kuniaki; Shinoda, Yukio; Seki, Tomomichi; Tanaka, Hideo; Akisawa, Atsushi

    2012-01-01

    Abstarct: In order to reduce CO 2 emissions in the passenger vehicle sector, mass introduction of electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) is required despite their high battery costs. This paper forecasts the rate at which EV/PHEV will penetrate into the market in the future and the effects of that spread on CO 2 reduction by using a learning curve for lithium-ion batteries, distribution of daily travel distance for each vehicle, and an optimal power generation planning model for charging vehicles. Taking into consideration each driver's economical viewpoint, the speed at which the EV/PHEV share of the new passenger vehicle market grows is fairly slow. The optimum calculation in our base case shows that the share of EV/PHEV is only a quarter even in 2050. However, the initial price and progress rate of batteries have a great effect on this share. Therefore, long-term economic support from the government and significant R and D innovation are required to reduce CO 2 drastically through cutting down battery price. The results also show how much the CO 2 emission intensity of power generation affects the CO 2 reduction rate by introducing EV/PHEV. - Highlights: ► Authors minimized the total cost of vehicle and power supply sectors until 2050. ► Simulation results show the penetration speed of PHEVs/EVs is not so fast. ► To accelerate it and reduce CO 2 , subsidies and innovations are required. ► The introduction of PHEVs/EVs is still reasonable even after the nuclear accident.

  7. Studies on Horizontal Axis Wind Turbine with Passive Teetered Brake & Damper Mechanism

    OpenAIRE

    SHIMIZU, Yukimaru; KAMADA, Yasunari; MAEDA, Takao

    1998-01-01

    In order to improve the reliability of megawatt wind turbines, the passive teetered brake & damper mechanism is applied. Its two unique effects, as its name implies, are braking and damping. The passive brake & damper mechanism is useful for variable speed control of the large wind turbine. It is comprised of teetering and feathering mechanisms. When the wind speed exceeds the rated wind speed, the blade is passively teetered in a downwind direction and, at the same time, a feathering mechani...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  10. Exploratory field trial of motorcycle autonomous emergency braking (MAEB): Considerations on the acceptability of unexpected automatic decelerations.

    Science.gov (United States)

    Savino, Giovanni; Pierini, Marco; Thompson, Jason; Fitzharris, Michael; Lenné, Michael G

    2016-11-16

    Autonomous emergency braking (AEB) acts to slow down a vehicle when an unavoidable impending collision is detected. In addition to documented benefits when applied to passenger cars, AEB has also shown potential when applied to motorcycles (MAEB). However, the feasibility of MAEB as practically applied to motorcycles in the real world is not well understood. In this study we performed a field trial involving 16 riders on a test motorcycle subjected to automatic decelerations, thus simulating MAEB activation. The tests were conducted along a rectilinear path at nominal speed of 40 km/h and with mean deceleration of 0.15 g (15% of full braking) deployed at random times. Riders were also exposed to one final undeclared brake activation with the aim of providing genuinely unexpected automatic braking events. Participants were consistently able to manage automatic decelerations of the vehicle with minor to moderate effort. Results of undeclared activations were consistent with those of standard runs. This study demonstrated the feasibility of a moderate automatic deceleration in a scenario of motorcycle travelling in a straight path, supporting the notion that the application of AEB on motorcycles is practicable. Furthermore, the proposed field trial can be used as a reference for future regulation or consumer tests in order to address safety and acceptability of unexpected automatic decelerations on a motorcycle.

  11. Wear determination in braking systems by radioisotopes

    International Nuclear Information System (INIS)

    Spruch, W.

    1979-01-01

    Friction and wear behaviour of friction couples has been tested applying loads and sliding speeds. The determination was carried out by direct measurements of the lining material and by surface activation of the opposite material with protons. The application limits of several braking materials could be determined and compared

  12. Mathematical Modeling of the Braking System of Wheeled Mainline Aircraft

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2016-01-01

    the aircraft braking mode with a slight increase in weight and complexity of the system.Mathematical modeling of the WBCS is intended to provide the possibility for studying the effect of various parameters on the braking process, choice of a rational law of the anti-skid automatics and minimization of the brake way on the runway in designing the WBCS, and its certification for compliance with AP25 under normal operation and in appearing of credible failures. The article presents differential equations of motion of the braking system of the aircraft landing gear wheel, which is an electro-hydraulic actuator to form the braking torque Мт, depending on the control signal Uу. The actuator comprises a remote control system of pressure and multi-disc friction brake. This mathematical model of the braking system of aircraft landing gear wheel allows us to study the braking process in a wide variation range of different parameters both of the braking system itself and its components, and of the aircraft parameters, runway conditions, and anti-skid system parameters, i.e. it provides an optimized braking process in conditions of changing a large number of different parameters the most important of which are: RFC, lifting force and aircraft weight; speed of the aircraft; parameters of the WBCS hydraulic units, etc.

  13. Brake for rollable platform

    Science.gov (United States)

    Morris, A. L.

    1974-01-01

    Frame-mounted brake is independent of wheels and consists of simple lever-actuated foot. Brake makes good contact with surface even though foot pad is at higher or lower level than wheels, this is particularly important when a rollable platform is used on irregular surface.

  14. Baseline tests of the C. H. Waterman Renault 5 electric passenger vehicle

    Science.gov (United States)

    Sargent, N. B.; Mcbrien, E. F.; Slavick, R. J.

    1977-01-01

    The Waterman vehicle, a four passenger Renault 5 GTL, performance test results are presented and characterized the state-of-the-art of electric vehicles. It was powered by sixteen 6-volt traction batteries through a two-step contactor controller actuated by a foot throttle to change the voltage applied to the 6.7 -kilowatt motor. The motor output shaft was connected to a front-wheel-drive transaxle that contains a four-speed manual transmission and clutch. The braking system was a conventional hydraulic braking system.

  15. Tire Models for Use in Braking Applications

    OpenAIRE

    Svendenius, Jacob

    2003-01-01

    The tire is a significant part for control of a vehicle. For a well-working brake system the contact properties between the tire and the ground is the limiting factor for a safe braking. To get optimal performance it is important that the system can utilize all friction resources. The brush tire model was a popular method in the 1960's and 1970's before the empirical approaches became dominating. The brush model gives an educational interpretation of the physics behind the tire behavi...

  16. AERIS : Eco-Vehicle Speed Control at Signalized Intersections Using I2V Communication

    Science.gov (United States)

    2012-06-01

    This report concentrates on a velocity advisory tool, or decision support system, for vehicles approaching an intersection using communication capabilities between the infrastructure and vehicles. The system uses available signal change information, ...

  17. Magnetorheological suspension electromagnetic brake

    International Nuclear Information System (INIS)

    Bica, Ioan

    2004-01-01

    The magnetorheological suspension (MRS) brake is of the monoblock type. The main part of the electromagnetic brake is an electromagnet, between whose poles two MRS disks are placed. For distances between disks of 0.65x10 -3 m±10%, revolutions of the electric motor, coupled to the electromagnetic brake, ranging between 200 and 1600 rev/min and braking powers of up to 85 W, there are no differences in revolutions between the disks of the electromagnetic brake. For fixed revolutions of the electric motor, the revolution of the parallel disk can be modified continuously by means of the intensity of the magnetic field. In all cases, the quantity of MRS is of 0.35x10 -3 kg

  18. WIND BRAKING OF MAGNETARS

    International Nuclear Information System (INIS)

    Tong, H.; Xu, R. X.; Qiao, G. J.; Song, L. M.

    2013-01-01

    We explore the wind braking of magnetars considering recent observations challenging the traditional magnetar model. There is evidence for strong multipole magnetic fields in active magnetars, but the dipole field inferred from spin-down measurements may be strongly biased by particle wind. Recent observations challenging the traditional model of magnetars may be explained naturally by the wind braking scenario: (1) the supernova energies of magnetars are of normal value; (2) the non-detection in Fermi observations of magnetars; (3) the problem posed by low magnetic field soft gamma-ray repeaters; (4) the relation between magnetars and high magnetic field pulsars; and (5) a decreasing period derivative during magnetar outbursts. Transient magnetars with L x rot may still be magnetic dipole braking. This may explain why low luminosity magnetars are more likely to have radio emissions. A strong reduction of the dipole magnetic field is possible only when the particle wind is very collimated at the star surface. A small reduction of the dipole magnetic field may result from detailed considerations of magnetar wind luminosity. In the wind braking scenario, magnetars are neutron stars with a strong multipole field. For some sources, a strong dipole field may no longer be needed. A magnetism-powered pulsar wind nebula will be one of the consequences of wind braking. For a magnetism-powered pulsar wind nebula, we should see a correlation between the nebula luminosity and the magnetar luminosity. Under the wind braking scenario, a braking index smaller than three is expected. Future braking index measurement of a magnetar may tell us whether magnetars are wind braking or magnetic dipole braking.

  19. Connected variable speed limits control and vehicle acceleration control to resolve moving jams

    NARCIS (Netherlands)

    Wang, M.; Daamen, W.; Hoogendoorn, S.P.; Van Arem, B.

    2015-01-01

    The vision of intelligent vehicles traveling in road networks has prompted numerous concepts to control future traffic flow, one of which is the in-vehicle actuation of traffic control signals. The key of this concept is using intelligent vehicles as actuators for traffic control systems, replacing

  20. The speed of change : motor vehicles and people in Africa, 1890-2000

    NARCIS (Netherlands)

    Gewald, J.B.; Luning, Sabine; Walraven, van K.

    2009-01-01

    In the early 1900s the motor-vehicle (car, bus, lorry or motorcycle) was introduced in sub-Saharan Africa. Initially the plaything and symbol of colonial domination, the motor-vehicle transformed the economic and social life of the continent. Indeed, the motor-vehicle is arguably the single most

  1. Indonesian commercial bus drum brake system temperature model

    International Nuclear Information System (INIS)

    Wibowo, D. B.; Haryanto, I.; Laksono, N. P.

    2016-01-01

    Brake system is the most significant aspect of an automobile safety. It must be able to slow the vehicle, quickly intervening and reliable under varying conditions. Commercial bus in Indonesia, which often stops suddenly and has a high initial velocity, will raise the temperature of braking significantly. From the thermal analysis it is observed that for the bus with the vehicle laden mass of 15 tons and initial velocity of 80 km/h the temperature is increasing with time and reaches the highest temperature of 270.1 °C when stops on a flat road and reaches 311.2 °C on a declination road angle, ø, 20°. These temperatures exceeded evaporation temperature of brake oil DOT 3 and DOT 4. Besides that, the magnitude of the braking temperature also potentially lowers the friction coefficient of more than 30%. The brakes are pressed repeatedly and high-g decelerations also causes brake lining wear out quickly and must be replaced every 1 month as well as the emergence of a large thermal stress which can lead to thermal cracking or thermal fatigue crack. Brake fade phenomenon that could be the cause of many buses accident in Indonesia because of the failure of the braking function. The chances of accidents will be even greater when the brake is worn and not immediately replaced which could cause hot spots as rivets attached to the brake drum and brake oil is not changed for more than 2 years that could potentially lower the evaporation temperature because of the effect hygroscopic.

  2. Indonesian commercial bus drum brake system temperature model

    Science.gov (United States)

    Wibowo, D. B.; Haryanto, I.; Laksono, N. P.

    2016-03-01

    Brake system is the most significant aspect of an automobile safety. It must be able to slow the vehicle, quickly intervening and reliable under varying conditions. Commercial bus in Indonesia, which often stops suddenly and has a high initial velocity, will raise the temperature of braking significantly. From the thermal analysis it is observed that for the bus with the vehicle laden mass of 15 tons and initial velocity of 80 km/h the temperature is increasing with time and reaches the highest temperature of 270.1 °C when stops on a flat road and reaches 311.2 °C on a declination road angle, ø, 20°. These temperatures exceeded evaporation temperature of brake oil DOT 3 and DOT 4. Besides that, the magnitude of the braking temperature also potentially lowers the friction coefficient of more than 30%. The brakes are pressed repeatedly and high-g decelerations also causes brake lining wear out quickly and must be replaced every 1 month as well as the emergence of a large thermal stress which can lead to thermal cracking or thermal fatigue crack. Brake fade phenomenon that could be the cause of many buses accident in Indonesia because of the failure of the braking function. The chances of accidents will be even greater when the brake is worn and not immediately replaced which could cause hot spots as rivets attached to the brake drum and brake oil is not changed for more than 2 years that could potentially lower the evaporation temperature because of the effect hygroscopic.

  3. Indonesian commercial bus drum brake system temperature model

    Energy Technology Data Exchange (ETDEWEB)

    Wibowo, D. B., E-mail: rmt.bowo@gmail.com; Haryanto, I., E-mail: ismoyo2001@yahoo.de; Laksono, N. P., E-mail: priyolaksono89@gmail.com [Mechanical Engineering Dept., Faculty of Engineering, Diponegoro University (Indonesia)

    2016-03-29

    Brake system is the most significant aspect of an automobile safety. It must be able to slow the vehicle, quickly intervening and reliable under varying conditions. Commercial bus in Indonesia, which often stops suddenly and has a high initial velocity, will raise the temperature of braking significantly. From the thermal analysis it is observed that for the bus with the vehicle laden mass of 15 tons and initial velocity of 80 km/h the temperature is increasing with time and reaches the highest temperature of 270.1 °C when stops on a flat road and reaches 311.2 °C on a declination road angle, ø, 20°. These temperatures exceeded evaporation temperature of brake oil DOT 3 and DOT 4. Besides that, the magnitude of the braking temperature also potentially lowers the friction coefficient of more than 30%. The brakes are pressed repeatedly and high-g decelerations also causes brake lining wear out quickly and must be replaced every 1 month as well as the emergence of a large thermal stress which can lead to thermal cracking or thermal fatigue crack. Brake fade phenomenon that could be the cause of many buses accident in Indonesia because of the failure of the braking function. The chances of accidents will be even greater when the brake is worn and not immediately replaced which could cause hot spots as rivets attached to the brake drum and brake oil is not changed for more than 2 years that could potentially lower the evaporation temperature because of the effect hygroscopic.

  4. Braking and cornering studies on an air cushion landing system

    Science.gov (United States)

    Daugherty, R. H.

    1983-01-01

    An experimental investigation was conducted to evaluate several concepts for braking and steering a vehicle equipped with an air cushion landing system (ACLS). The investigation made use of a modified airboat equipped with an ACLS. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting braking concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations two to three times higher than those from conventional nose-gear steering. However, this concept was still felt to provide reasonably precise steering control for the ACLS-equipped vehicle.

  5. Improved Electromagnetic Brake

    Science.gov (United States)

    Martin, Toby B.

    2004-01-01

    A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may

  6. Speed support through the intelligent vehicle : perspective, estimated effects and implementation aspects.[Deliverable of the Intelligent Vehicles project, part of the Traffic Management project within TRANSUMO (TRANsition to SUstainable MObility).

    NARCIS (Netherlands)

    Morsink, P. Goldenbeld, C. Dragutinovic, N. Marchau, V. Walta, L. & Brookhuis, K.

    2008-01-01

    Speed management is a central theme in traffic management, aiming to optimize traffic in terms of safety, efficiency and the environment, by reducing speeding and speed differences in traffic. Intelligent vehicles can perform tasks that conventional measures cannot do at all, or do less efficiently.

  7. Development of antilock braking system based on various intelligent control system

    NARCIS (Netherlands)

    Aparow, V.R.; Ahmad, F.; Hassan, M.Z.; Hudha, K.; Othman, M.

    2012-01-01

    This paper presents about the development of an Antilock Braking System (ABS) using quarter vehicle model and control the ABS using different type of controllers. Antilock braking system (ABS) is an important part in vehicle system to produce additional safety for drivers. In general, Antilock

  8. Kinetic energy recovery and power management for hybrid electric vehicles

    OpenAIRE

    Suntharalingam, P

    2011-01-01

    The major contribution of the work presented in this thesis is a thorough investigation of the constraints on regenerative braking and kinetic energy recovery enhancement for electric/hybrid electric vehicles during braking. Regenerative braking systems provide an opportunity to recycle the braking energy, which is otherwise dissipated as heat in the brake pads. However, braking energy harnessing is a relatively new concept in the automotive sector which still requires further research and de...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Influence of Vehicle Speed on the Characteristics of Driver's Eye Movement at a Highway Tunnel Entrance during Day and Night Conditions: A Pilot Study.

    Science.gov (United States)

    Qin, Li; Dong, Li-Li; Xu, Wen-Hai; Zhang, Li-Dong; Leon, Arturo S

    2018-04-02

    The aim of this study was to investigate how vehicle speed influences the characteristics of driver's eye movement at highway tunnel entrances during day and night. In this study, six drivers' eye movement data (from 200 m before tunnel entrance to 200 m inside tunnel entrance) under five predetermined vehicle speeds (40, 50, 60, 70 and 80 km/h) in the daytime and three predetermined vehicle speeds (40, 60 and 80 km/h) in the nighttime were recorded using the non-intrusive Dikablis Professional eye-tracking system. Pupil size, the average fixation duration time and the average number of fixation were analyzed and then the influence of the vehicle speed on these parameters was evaluated by means of IBM SPSS Statistics 20.0. The results for pupil size in daytime increased when approaching the tunnel entrance, while as for nighttime, pupil size decreased when approaching the tunnel entrance and then increased after entering the tunnel. The pupil size in daytime has a significant negative correlation with vehicle speed, while the pupil size in nighttime did not show a significant association with vehicle speed. Furthermore, the average fixation duration in daytime increased when entering the tunnel, and had a significant negative correlation with vehicle speed. Also, the average number of fixations in daytime decreased when entering the tunnel and has a significant negative correlation with vehicle speed. However, the average fixation duration and the average number of fixations in nighttime did not show any significant association with vehicle speed. Moreover, limitations and future directions of the study are discussed for the further investigation.

  11. Reliability analysis of high-speed tracked vehicles in the polish army

    Directory of Open Access Journals (Sweden)

    Kończak Jarosław

    2017-06-01

    Full Text Available The Polish Armed Forces use tracked vehicles that serve as a core element of the ground combat forces. These vehicles are capable of fighting in all kinds of terrain conditions, in any season of the year. Combat missions are often fought in areas where even no dirt roads are available. The present paper assesses the reliability of tracked vehicles in the context of their irregular operation, as well as service- and maintenance-related vulnerability.

  12. Load proportional safety brake

    Science.gov (United States)

    Cacciola, M. J.

    1979-01-01

    This brake is a self-energizing mechanical friction brake and is intended for use in a rotary drive system. It incorporates a torque sensor which cuts power to the power unit on any overload condition. The brake is capable of driving against an opposing load or driving, paying-out, an aiding load in either direction of rotation. The brake also acts as a no-back device when torque is applied to the output shaft. The advantages of using this type of device are: (1) low frictional drag when driving; (2) smooth paying-out of an aiding load with no runaway danger; (3) energy absorption proportional to load; (4) no-back activates within a few degrees of output shaft rotation and resets automatically; and (5) built-in overload protection.

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

    Science.gov (United States)

    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.

  14. Simulation and experimental research on trans-media vehicle water-entry motion characteristics at low speed.

    Science.gov (United States)

    Yang, Jian; Li, Yongli; Feng, Jinfu; Hu, Junhua; Liu, An

    2017-01-01

    The motion characteristics of trans-media vehicles during the water-entry process were explored in this study in an effort to obtain the optimal water-entry condition of the vehicle for developing a novel, single control strategy integrating underwater non-control and in-air control. A water-entry dynamics model is established by combining the water-entry motion characteristics of the vehicle in uncontrolled conditions at low speed with time-varying parameters (e.g. buoyancy, added mass). A water-entry experiment is designed to confirm the effectiveness of the established model. After that, by comparing the experimental results with the simulated results, the model is further modified to more accurately reflect water-entry motion. The change laws of the vehicle's attitude and position during the water-entry process are also obtained by analyzing the simulation of the modified model under different velocity, angle, and angle of attack conditions. The results presented here have guiding significance for the future realization of reaching the stable underwater navigation state of the vehicle after water-entry process.

  15. Simulation and experimental research on trans-media vehicle water-entry motion characteristics at low speed.

    Directory of Open Access Journals (Sweden)

    Jian Yang

    Full Text Available The motion characteristics of trans-media vehicles during the water-entry process were explored in this study in an effort to obtain the optimal water-entry condition of the vehicle for developing a novel, single control strategy integrating underwater non-control and in-air control. A water-entry dynamics model is established by combining the water-entry motion characteristics of the vehicle in uncontrolled conditions at low speed with time-varying parameters (e.g. buoyancy, added mass. A water-entry experiment is designed to confirm the effectiveness of the established model. After that, by comparing the experimental results with the simulated results, the model is further modified to more accurately reflect water-entry motion. The change laws of the vehicle's attitude and position during the water-entry process are also obtained by analyzing the simulation of the modified model under different velocity, angle, and angle of attack conditions. The results presented here have guiding significance for the future realization of reaching the stable underwater navigation state of the vehicle after water-entry process.

  16. Auxiliary brakes for trucks : research into the behaviour of a tractor-semi-trailer combination during emergency breaking.

    NARCIS (Netherlands)

    Dijks, A. Blijswijk, W.A.M. van Genugten, J. van Meeke, G.J.M. & Schlösser, L.H.M.

    1976-01-01

    The purpose of the research was to obtain an insight into various secondary braking systems for goods vehicles. Practical tests were carried out with a tractor- semi-trailer combination. The performance of various split braking systems as well as spring brake actuators are shown. With nearly all of

  17. Investigation Into The Model Of The Vehicle System For Speed Support

    Directory of Open Access Journals (Sweden)

    Jurij Grigorovič

    2013-12-01

    Full Text Available The paper presents a rectilinear motion of a car modelled applyingsoftware package “Matlab/Simulink“ where two vehicles aremoving simultaneously one after the other. The parameters ofeach vehicle have been identified separately assessing a driver,road and environment.

  18. Evaluation of a sudden brake warning system: effect on the response time of the following driver.

    Science.gov (United States)

    Isler, Robert B; Starkey, Nicola J

    2010-07-01

    This study used a video-based braking simulation dual task to carry out a preliminary evaluation of the effect of a sudden brake warning system (SBWS) in a leading passenger vehicle on the response time of the following driver. The primary task required the participants (N=25, 16 females, full NZ license holders) to respond to sudden braking manoeuvres of a lead vehicle during day and night driving, wet and dry conditions and in rural and urban traffic, while concurrently performing a secondary tracking task using a computer mouse. The SBWS in the lead vehicle consisted of g-force controlled activation of the rear hazard lights (the rear indicators flashed), in addition to the standard brake lights. Overall, the results revealed that responses to the braking manoeuvres of the leading vehicles when the hazard lights were activated by the warning system were 0.34 s (19%) faster compared to the standard brake lights. The SBWS was particularly effective when the simulated braking scenario of the leading vehicle did not require an immediate and abrupt braking response. Given this, the SBWS may also be beneficial for allowing smoother deceleration, thus reducing fuel consumption. These preliminary findings justify a larger, more ecologically valid laboratory evaluation which may lead to a naturalistic study in order to test this new technology in 'real world' braking situations. Copyright 2009 Elsevier Ltd. All rights reserved.

  19. Numerical Modeling of Disc Brake System in Frictional Contact

    Directory of Open Access Journals (Sweden)

    A. Belhocine

    2014-03-01

    Full Text Available Safety aspect in automotive engineering has been considered as a number one priority in development of new vehicle. Each single system has been studied and developed in order to meet safety requirement. Instead of having air bag, good suspension systems, good handling and safe cornering, there is one most critical system in the vehicle which is brake systems. The objective of this work is to investigate and analyse the temperature distribution of rotor disc during braking operation using ANSYS Multiphysics. The work uses the finite element analysis techniques to predict the temperature distribution on the full and ventilated brake disc and to identify the critical temperature of the rotor by holding account certain parameters such as; the material used, the geometric design of the disc and the mode of braking. The analysis also gives us, the heat flux distribution for the two discs.

  20. Evaluation of the Flush/Fill and High-Pressure Air Purge Procedures for Converting Army Vehicles to Silicone Brake Fluid.

    Science.gov (United States)

    1982-02-01

    Inhlalation Ally lnon-lethal C’AR. NiLO FTA . TELR LDLo Acute or chronic All except inhalation Decath tDeathl LD50 Acute All except inhalation Not applic-ihle D...Improved Tow Vehicle US Army Europe & Seventh Army US Army Tank-Automotive Command ATTN: AEAGC- FMD ATTN: DRCPM-ITV-T APO NY 09403 Warren, Mi 48090

  1. Designing Sustainable Public Transportation: Integrated Optimization of Bus Speed and Holding Time in a Connected Vehicle Environment

    Directory of Open Access Journals (Sweden)

    Wei Wu

    2016-11-01

    Full Text Available Developing public transportation and giving priority to buses is a feasible solution for improving the level of public transportation service, which facilitates congestion alleviation and prevention, and contributes to urban development and city sustainability. This paper presents a novel bus operation control strategy including both holding control and speed control to improve the level of service of transit systems within a connected vehicle environment. Most previous work focuses on optimization of signal timing to decrease the bus signal delay by assuming that holding control is not applied; the speed of buses is given as a constant input and the acceleration and deceleration processes of buses can be neglected. This paper explores the benefits of a bus operation control strategy to minimize the total cost, which includes bus signal delay, bus holding delay, bus travel delay, acceleration cost due to frequent stops and intense driving. A set of formulations are developed to explicitly capture the interaction between bus holding control and speed control. Experimental analysisand simulation tests have shown that the proposed integrated operational model outperforms the traditional control, speed control only, or holding control only strategies in terms of reducing the total cost of buses. The sensitivity analysis has further demonstrated the potential effectiveness of the proposed approach to be applied in a real-time bus operation control system under different levels of traffic demand, bus stop locations, and speed limits.

  2. Scania RBS brake system; Das Bremssystem EBS von Scania

    Energy Technology Data Exchange (ETDEWEB)

    Winterhagen, J.

    1996-09-01

    Scania claims to be the first producer of industrial vehicles to market an electronic braking system (EBS) combined with disc brakes for all axles. The new braking systems for long-distance trailers were presented for the first time at the IAA, Hanover, in September 1996. (orig.) [Deutsch] Scania ist nach eigenen Angaben der erste Lkw-Hersteller, der eine elektronisch geregelte Bremsanlage (EBS) in Kombination mit Scheibenbremsen an allen Achsen auf den Markt bringt. Der Oeffentlichkeit stellt Scania das neue Bremssystem fuer die Fernverkehrs-Zugmaschinen der Baureihe 4 zum ersten Mal auf der IAA in Hannover im September 1996 vor. (orig.)

  3. Benchmarking of regenerative braking for a fully electric car

    NARCIS (Netherlands)

    Varocky, B.J.; Nijmeijer, H.; Jansen, S.; Besselink, I.J.M.; Mansvelder, R.; Mansvelders, R.E.

    2011-01-01

    Short range of electric vehicles is one of the stumbling blocks in the way of electric cars to gaining wide user acceptance and becoming a major market player. The possibility to recover vehicle energy otherwise lost as heat during braking is an inherent advantage of a hybrid electric or a fully

  4. Network Provisioning for High Speed Vehicles Moving along Predictable Routes - Part 1: Spiderman Handover

    OpenAIRE

    Maureira , Juan-Carlos; Dujovne , Diego; Dalle , Olivier

    2009-01-01

    This report presents our on-going work on a new system designed to provide a continuous network connectivity to communicating devices located on-board a vehicle moving at ”high speed” with a predictable trajectory such as trains, subways or buses. The devices on-board the vehicle form a sub-network called the ”in-motion network”. This system we propose is composed of two parts. The mobile part, called Spiderman Device (SD), installed on the roof of the vehicle, and the fixed part is composed ...

  5. Unidirectional high gain brake stop

    Science.gov (United States)

    Lang, David J. (Inventor)

    1987-01-01

    This invention relates to a unidirectional high gain brake arrangement that includes in combination a shaft mounted for rotation within a housing. The shaft is rotatable in either direction. A brake is selectively releasably coupled to the housing and to the shaft. The brake has a first member. An intermittent motion device is respectively coupled through the first member to the housing and through a one-way clutch to the shaft. The brake also has a second member that is mechanically coupled to the first brake member and to the housing. The intermittent motion device causes the brake to be activated by movement imparted to the first brake member after a preset number of revolutions of the shaft in one direction. The brake is released by rotation of the shaft in an opposite direction whereby torque transmitted through the one-way clutch to the first brake member is removed.

  6. Research study on antiskid braking systems for the space shuttle

    Science.gov (United States)

    Auselmi, J. A.; Weinberg, L. W.; Yurczyk, R. F.; Nelson, W. G.

    1973-01-01

    A research project to investigate antiskid braking systems for the space shuttle vehicle was conducted. System from the Concorde, Boeing 747, Boeing 737, and Lockheed L-1011 were investigated. The characteristics of the Boeing 737 system which caused it to be selected are described. Other subjects which were investigated are: (1) trade studies of brake control concepts, (2) redundancy requirements trade study, (3) laboratory evaluation of antiskid systems, and (4) space shuttle hardware criteria.

  7. Roundabouts converted for road trains and the effect on vehicle speed

    DEFF Research Database (Denmark)

    Tønning, Charlotte; Agerholm, Niels

    2016-01-01

    on the measured time use between two location identified in the roundabout for private cars driving under free flow conditions, an estimation of the speed with/after compared to the speed without/before the redesign is made for in total 100 cars per week per location. The very first tentative results show...

  8. NOISE AS AN INDIRECT CRITERION FOR EVALUATING THE CRITICAL SPEED OF VEHICLE TIRE AT HYDROPLANING

    Directory of Open Access Journals (Sweden)

    V. Karpenko

    2017-12-01

    Full Text Available An alternative method for determining the critical rolling speed of automobile tires with various tread patterns during hydroplaning is considered. The critical speed of the car at which the hydroplaning process takes place is determined. This method is based on recording the tire noise emission when driving on a wet road pavement.

  9. Side-suspended High- Tc Superconducting Maglev Prototype Vehicle Running at a High Speed in an Evacuated Circular Test Track

    International Nuclear Information System (INIS)

    Zhou, Dajin; Zhao, Lifeng; Cui, Chenyu; Zhang, Yong; Guo, Jianqiang; Zhao, Yong

    2017-01-01

    High- T c superconductor (HTS) and permanent magnetic guideway (PMG) based maglev train is intensively studied in China, Japan, Germany and Brazil, mainly through static or vibration test. Amongst these studies, only a few of reports are available for the direct and effective assessment on the dynamic performance of the HTS maglev vehicle by running on a straight or circular PMG track. The highest running speed of these experiments is lower than 50 km/h. In this paper, a side-suspended HTS permanent magnetic guideway maglev system was proposed and constructed in order to increase the running speed in a circular track. By optimizing the arrangement of YBCO bulks besides the PMG, the side-suspended HTS maglev prototype vehicle was successfully running stably at a speed as high as 150 km/h in a circular test track with 6.5 m in diameter, and in an evacuated tube environment, in which the pressure is 5 × 10 3 Pa. (paper)

  10. Modified Motor Vehicles Travel Speed Models on the Basis of Curb Parking Setting under Mixed Traffic Flow

    Directory of Open Access Journals (Sweden)

    Zhenyu Mei

    2012-01-01

    Full Text Available The ongoing controversy about in what condition should we set the curb parking has few definitive answers because comprehensive research in this area has been lacking. Our goal is to present a set of heuristic urban street speed functions under mixed traffic flow by taking into account impacts of curb parking. Two impacts have been defined to classify and quantify the phenomena of motor vehicles' speed dynamics in terms of curb parking. The first impact is called Space impact, which is caused by the curb parking types. The other one is the Time impact, which results from the driver maneuvering in or out of parking space. In this paper, based on the empirical data collected from six typical urban streets in Nanjing, China, two models have been proposed to describe these phenomena for one-way traffic and two-way traffic, respectively. An intensive experiment has been conducted in order to calibrate and validate these proposed models, by taking into account the complexity of the model parameters. We also provide guidelines in terms of how to cluster and calculate those models' parameters. Results from these models demonstrated promising performance of modeling motor vehicles' speed for mixed traffic flow under the influence of curb parking.

  11. The intelligent brake: SBS brakes safely and comfortably in all situations; Die intelligente Bremse: SBS verzoegert stets sicher und komfortabel

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-07-01

    The Vision SLR study demonstrates the technology with which DaimlerChrysler vehicles will be equipped in the next century. The car that won the Gran Turismo incorporates the Sensortronic Brake System (SBS), an electrohydraulic braking system for optimum safety and comfort even in critical situations. [German] Die Fahrzeugstudie Vision SLR demonstriert eindrucksvoll die Technik, mit der DaimlerChrysler Fahrzeuge des kommenden Jahrhunderts ausstatten wird. Eine Besonderheit des Gran Turismo-Silberpfeils: das Sensortronic Brake System (SBS), ein elektrohydraulisches Bremssystem, das auch in kritischen Situationen optimale Fahrsicherheit und Komfort bietet. (orig.)

  12. IR-camera methods for automotive brake system studies

    Science.gov (United States)

    Dinwiddie, Ralph B.; Lee, Kwangjin

    1998-03-01

    Automotive brake systems are energy conversion devices that convert kinetic energy into heat energy. Several mechanisms, mostly related to noise and vibration problems, can occur during brake operation and are often related to non-uniform temperature distribution on the brake disk. These problems are of significant cost to the industry and are a quality concern to automotive companies and brake system vendors. One such problem is thermo-elastic instabilities in brake system. During the occurrence of these instabilities several localized hot spots will form around the circumferential direction of the brake disk. The temperature distribution and the time dependence of these hot spots, a critical factor in analyzing this problem and in developing a fundamental understanding of this phenomenon, were recorded. Other modes of non-uniform temperature distributions which include hot banding and extreme localized heating were also observed. All of these modes of non-uniform temperature distributions were observed on automotive brake systems using a high speed IR camera operating in snap-shot mode. The camera was synchronized with the rotation of the brake disk so that the time evolution of hot regions could be studied. This paper discusses the experimental approach in detail.

  13. Impacts of Bus-stops on the Speed of Motorized Vehicles under Heterogeneous Traffic Conditions: A Case-Study of Delhi, India

    Directory of Open Access Journals (Sweden)

    Prateek Bansal

    2014-06-01

    Full Text Available The presence of friction generators1 such as bus-stops, intersections, petrol pumps and pedestrian crossings, etc. significantly influences the speed of traffic stream. Among all the friction generators, understanding the impact of bus-stops is particularly important from planning and modeling perspective in the Indian context. Therefore, this study presents a methodology to quantify the impact of bus-stops on the speed of other motorized vehicles (the total motorized vehicle fleet minus the buses under heterogeneous traffic conditions. The methodology was validated on the typical urban arterials in Delhi, India. Two types of data, location of bus-stops and speed profiles of motorized vehicles, were collected by GPS and V-box respectively. These two data sets were mapped and merged using ArcGIS. To understand the nature of traffic stream near bus-stops, ‘influence regions’ of bus-stops were extracted. Later, characteristic parameters such as lengths of the influence regions and average speeds in the influence regions were computed. Finally, 95% confidence intervals of these characteristic parameters were obtained and regression analysis was performed to quantify the impact of bus-stops on the speed of motorized vehicles. The results of study suggest that the influence region of bus-stops on the corridors investigated varies from 140–170 meters and average speed of motorized vehicles in the influence region is reduced by 26–38% of the free flow speed. These findings can better inform planners about the speeds used in traffic flow and travel demand modeling under heterogeneous conditions by helping them in accounting for the speed-reducing impacts of bus-stops. Moreover, transit planners may also consider the magnitudes and characteristics of the influence regions of bus-stops while determining their locations along the corridor to minimize their adverse impacts on the speed of other motorized vehicles.

  14. Implementation Of Fuzzy Automated Brake Controller Using TSK Algorithm

    Science.gov (United States)

    Mittal, Ruchi; Kaur, Magandeep

    2010-11-01

    In this paper an application of Fuzzy Logic for Automatic Braking system is proposed. Anti-blocking system (ABS) brake controllers pose unique challenges to the designer: a) For optimal performance, the controller must operate at an unstable equilibrium point, b) Depending on road conditions, the maximum braking torque may vary over a wide range, c) The tire slippage measurement signal, crucial for controller performance, is both highly uncertain and noisy. A digital controller design was chosen which combines a fuzzy logic element and a decision logic network. The controller identifies the current road condition and generates a command braking pressure signal Depending upon the speed and distance of train. This paper describes design criteria, and the decision and rule structure of the control system. The simulation results present the system's performance depending upon the varying speed and distance of the train.

  15. Research tool for the investigation of the driver/brake pedal interface; Forschungswerkzeug zur Untersuchung der Schnittstelle Fahrer/Bremspedal

    Energy Technology Data Exchange (ETDEWEB)

    Bill, K.H.; Breuer, B. [Technische Hochschule Darmstadt (Germany). Fachgebiet Fahrzeugtechnik; Leber, M. [DaimlerChrysler AG, Stuttgart (Germany); Becker, H. [Ford-Werke AG, Koeln (Germany)

    1999-02-01

    The driver/brake pedal interface gains increasing importance when one considers the increasing demands for driver safety and comfort in the vehicle, as well as Brake-by-Wire and braking assistance systems. The decoupling of the brake pedal from the rest of the brake system in the Brake-by-Wire power control braking system makes it necessary to give the brake pedal a specific characteristic. While this can only be slightly influenced in conventional brake systems due to the energetic coupling with the brake hydraulics, in future concepts this interface must be completely re-designed. At the Department of Automotive Engineering at the Technical University of Darmstadt (fzd), supported by the automobile producer Ford, Inc., new methods for the investigation of brake pedal feel under actual conditions with a specially designed test vehicle have been the subject of research. (orig.) [Deutsch] Mit der absehbaren Einfuehrung von Brake-by-Wire und Bremsassistenzsystemen gewinnt die Schnittstelle Fahrer / Bremspedal zunehmend an Bedeutung. Die Entkopplung des Bremspedals vom restlichen Bremssystem macht bei Brake-by-Wire-Anlagen eine gezielte Auslegung der Bremspedalcharakteristik notwendig. Waehrend diese bei konventionellen Bremssystemen infolge der energetischen Kopplung mit der Bremsenhydraulik nur in engen Grenzen beeinflusst werden kann, muss bei zukuenftigen Konzepten diese Schnittstelle vollstaendig neu ueberdacht werden. Am Fachgebiet Fahrzeugtechnik der Technischen Universitaet Darmstadt (fzd) wird, unterstuetzt durch die Ford-Werke AG, an neuen Ansaetzen zur Untersuchung des Bremspedalgefuehls unter realen Bedingungen mit einem speziell hierfuer aufgebauten Versuchstraeger geforscht. (orig.)

  16. Simulation of speed control in acceleration mode of a heavy duty vehicle; Ogatasha no kasokuji ni okeru shasoku seigyo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Endo, S; Ukawa, H [Isuzu Advanced Engineering Center, Ltd., Tokyo (Japan); Sanada, K; Kitagawa, A [Tokyo Institute of Technology, Tokyo (Japan)

    1997-10-01

    A control law of speed of a heavy duty vehicle in acceleration mode is presented, which is an extended version of a control law in deceleration mode proposed by the authors. The control law is based on constant acceleration strategy. Using the control law, target velocity and target distance can be performed. Both control laws for acceleration and deceleration mode can be represented by a unified mathematical formulae. Some simulation results are shown to demonstrate the control performance. 7 refs., 9 figs., 2 tabs.

  17. Cognitive radio networks efficient resource allocation in cooperative sensing, cellular communications, high-speed vehicles, and smart grid

    CERN Document Server

    Jiang, Tao; Cao, Yang

    2015-01-01

    PrefaceAcknowledgmentsAbout the AuthorsIntroductionCognitive Radio-Based NetworksOpportunistic Spectrum Access NetworksCognitive Radio Networks with Cooperative SensingCognitive Radio Networks for Cellular CommunicationsCognitive Radio Networks for High-Speed VehiclesCognitive Radio Networks for a Smart GridContent and OrganizationTransmission Slot Allocation in an Opportunistic Spectrum Access NetworkSingle-User Single-Channel System ModelProbabilistic Slot Allocation SchemeOptimal Probabilistic Slot AllocationBaseline PerformanceExponential DistributionHyper-Erlang DistributionPerformance An

  18. Development of mechanical brake assist; Mechanical brake assist no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, M; Shingyoji, S; Nakamura, I; Tagawa, T; Saito, Y; Ishihara, T; Kobayashi, S; Yoshida, M [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    We have recognized that there are drivers who cannot apply strong brake pedal force , in spite of the necessity of hard braking in emergencies. We have developed a `mechanical brake assist system` which assists drivers appropriately, according to the drivers` characteristics based on studying the characteristic`s of conditions of drivers applying the brake pedal force in emergency conditions. 2 refs., 7 figs., 1 tab.

  19. Brake hydraulics simulation with real-time capability. From hydraulics plan to implementation: the Bosch ESP 5.7 as an example; Echtzeitfaehige Bremshydrauliksimulation. Vom Hydraulikplan zur Implementierung am Beispiel des Bosch ESP 5.7

    Energy Technology Data Exchange (ETDEWEB)

    Marc, E.; Oliver, P.; Thies, W. [Tesis Dynaware (Germany)

    2001-11-01

    For the development and testing of ABS/ESP control units, both the detailed simulation of the vehicle and drive train dynamics as well as the dynamic behaviour of the hydraulic system are important. The signals coming from the control unit that control the valves in the brake hydraulic system cause pressure changes in the brake system and thus affect the braking torque. In turn, the changes in the speed of the wheels are fed back to the control unit via sensors. The objective of an ABS control strategy is to prevent the wheels from locking during braking in order to ensure and maintain the steerability of the vehicle, while the ESP action also attempts to achieve a stabilization of the yawing motion by means of active braking. (orig.) [German] Fuer die Entwicklung und den Test von ABS/ESP-Steuergeraeten ist neben der detaillierten Simulation von Fahr- und Antriebsstrangdynamik auch das dynamische Verhalten des hydraulischen Systems wichtig. Die vom Steuergeraet kommenden Signale zur Ansteuerung der Ventile in der Bremshydraulik bewirken Druckaenderungen im Bremssystem und somit der Bremsmomente. Die Aenderungen der Raddrehzahlen werden wiederum ueber Sensoren dem Steuergeraet zurueckgemeldet. Ziel einer ABS-Regelstrategie ist das Verhindern des Blockierens der Raeder beim Bremsen, um die Lenkbarkeit des Fahrzeugs zu erhalten, waehrend bei einem ESP-Eingriff durch aktives Bremsen zusaetzlich eine Stabilisierung der Gierbewegung erfolgen soll, wie der folgende Beitrag von Tesis Dynaware zeigt. (orig.)

  20. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    International Nuclear Information System (INIS)

    Wibowo,; Zakaria,; Lambang, Lullus; Triyono,; Muhayat, Nurul

    2016-01-01

    The most effective chassis control system for improving vehicle safety during severe braking is anti-lock braking system (ABS). Antilock effect can be gained by vibrate the pad brake at 7 to 20 cycle per second. The aim of this study is to design a new method of antilock braking system with membrane elastic vibrated by solenoid. The influence of the pressure fluctuations of brake fluid is investigated. Vibration data is collected using a small portable accelerometer-slam stick. The experiment results that the vibration of brake pad caused by controlled solenoid excitation at 10 Hz is obtained by our new method. The result of measurements can be altered by varying brake fluid pressure.

  1. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    Energy Technology Data Exchange (ETDEWEB)

    Wibowo,, E-mail: wibowo-uns@yahoo.com; Zakaria,, E-mail: zakaaria27@gmail.com; Lambang, Lullus, E-mail: lulus-l@yahoo.com; Triyono,, E-mail: tyon-bila@yahoo.co.id; Muhayat, Nurul, E-mail: nurulmuhayat@ymail.com [Mechanical Engineering Department, Sebelas Maret University, Surakarta 57128 (Indonesia)

    2016-03-29

    The most effective chassis control system for improving vehicle safety during severe braking is anti-lock braking system (ABS). Antilock effect can be gained by vibrate the pad brake at 7 to 20 cycle per second. The aim of this study is to design a new method of antilock braking system with membrane elastic vibrated by solenoid. The influence of the pressure fluctuations of brake fluid is investigated. Vibration data is collected using a small portable accelerometer-slam stick. The experiment results that the vibration of brake pad caused by controlled solenoid excitation at 10 Hz is obtained by our new method. The result of measurements can be altered by varying brake fluid pressure.

  2. Development of brake assist system. Summary of hydraulic brake assist system; Brake assist system no kaihatsu. Ekiatsushiki brake assist system no gaiyo

    Energy Technology Data Exchange (ETDEWEB)

    Hara, M; Ota, M; Shimizu, S [Toyota, Motor Corp., Aichi (Japan)

    1997-10-01

    We have already developed vacuum-booster-type Brake Assist System that supplies additional braking power when panic braking is recognized. We are convinced that the expansion of Brake Assist System will become more important issue in the future. Therefore we have developed hydraulic Brake Assist System with increasing its controllability and reducing its discomfort. This system have a brake pressure sensor to detect emergency braking operation and an antilock device to supply additional braking power. 8 refs., 11 figs.

  3. Power-based electric vehicle energy consumption model: Model development and validation

    International Nuclear Information System (INIS)

    Fiori, Chiara; Ahn, Kyoungho; Rakha, Hesham A.

    2016-01-01

    Highlights: • The study developed an instantaneous energy consumption model (VT-CPEM) for EVs. • The model captures instantaneous braking energy regeneration. • The model can be used for transportation modeling and vehicle applications (e.g. eco-routing). • The proposed model can be easily calibrated using publically available EV data. • Usages of air conditioning and heating systems reduce EV energy consumption by up to 10% and 24%, respectively. - Abstract: The limited drive range (The maximum distance that an EV can travel.) of Electric Vehicles (EVs) is one of the major challenges that EV manufacturers are attempting to overcome. To this end, a simple, accurate, and efficient energy consumption model is needed to develop real-time eco-driving and eco-routing systems that can enhance the energy efficiency of EVs and thus extend their travel range. Although numerous publications have focused on the modeling of EV energy consumption levels, these studies are limited to measuring energy consumption of an EV’s control algorithm, macro-project evaluations, or simplified well-to-wheels analyses. Consequently, this paper addresses this need by developing a simple EV energy model that computes an EV’s instantaneous energy consumption using second-by-second vehicle speed, acceleration and roadway grade data as input variables. In doing so, the model estimates the instantaneous braking energy regeneration. The proposed model can be easily implemented in the following applications: in-vehicle, Smartphone eco-driving, eco-routing and transportation simulation software to quantify the network-wide energy consumption levels for a fleet of EVs. One of the main advantages of EVs is their ability to recover energy while braking using a regenerative braking system. State-of-the-art vehicle energy consumption models consider an average constant regenerative braking energy efficiency or regenerative braking factors that are mainly dependent on the vehicle’s average

  4. New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

    Directory of Open Access Journals (Sweden)

    Nazim Mir-Nasiri

    2008-11-01

    Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion..

  5. New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

    Directory of Open Access Journals (Sweden)

    Nazim Mir-Nasiri

    2005-09-01

    Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion.

  6. Safety brake for tape reels

    Science.gov (United States)

    Carle, C. E.

    1977-01-01

    All-mechanical device senses end of tape and stops reel, even in event of electronic system failure. Assembly includes stop to prevent brake from overriding tape. Recentering mechanism returns brake to neutral position after torque is removed from reels.

  7. Effect of the crone suspension control system on braking

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, X.; Oustaloup, A. [Bordeaux-1 Univ., Talence (France). Lab. d' Automatique et de Productique; Nouillant, C. [Bordeaux-1 Univ., Talence (France). Lab. d' Automatique et de Productique]|[DRIA-PSA Peugeot Citroen, Velizy - Villacoublay (France)

    2001-07-01

    Semi-active or active suspensions not only increase driving comfort, but also permit the control system to be switched over if required in order to improve the transmission of forces at the points of contact between tire and road surface by minimizing the dynamic wheel loads. It may also be possible to use these systems to control wheel load distribution and, thus, influence braking or steering performance by changing the distribution of normal forces between the front and rear axles. This article examines the effect of the CRONE suspension control system on braking. The central idea is to use continuously variable dampers and fast load levelling devices to distribute the normal forces of tire between the front and rear axles. The basis principle is explained using known dynamic properties of active suspension, vehicles and tires. The effect of active suspension on vehicle response during braking is then evaluated using computer simulations from a two-wheel vehicle model. (orig.)

  8. 49 CFR 571.500 - Standard No. 500; Low-speed vehicles.

    Science.gov (United States)

    2010-10-01

    ... replacement of any component is allowed after the start of the first performance test. S6.3.3. Tire inflation.... General test conditions. Each vehicle must meet the performance limit specified in S5(a) under the... standard reference test tire that meets the specifications of American Society for Testing and Materials...

  9. Hybrid-Vehicle Transmission System

    Science.gov (United States)

    Lupo, G.; Dotti, G.

    1985-01-01

    Continuously-variable transmission system for hybrid vehicles couples internal-combustion engine and electric motor section, either individually or in parallel, to power vehicle wheels during steering and braking.

  10. UNDESIRED SPLASH OVER ON EQUIPMENTS USING INDUCTIVE SENSORS FOR MONITORING AUTOMOTIVE VEHICLES' CONTROLLED SPEED

    Directory of Open Access Journals (Sweden)

    Silvio Monteiro

    Full Text Available This article aims to evaluate instruments that oversight traffic flow electronically, using inductive surface sensors, based on the change of local magnetic field. More specifically, we study the possibility of false speed detections, due to the manifestation of the phenomenon called splash over - which means a space splash of the magnetic field lines out of the measuring zone. We show, through the literature, and practical simulations, the damage that can be caused by splash on the correct speed measurement and identification of the car under suspicions. It is also presented solutions to inhibiting unwanted velocity measurements due to this effect.

  11. Analysis, control and design of speed control of electric vehicles delayed model

    DEFF Research Database (Denmark)

    Khooban, Mohammad-Hassan; ShaSadeghi, Mokhtar; Niknam, Taher

    2017-01-01

    The purpose of this study is to suggest an optimal multi-objective fuzzy fractional-order PIλDμPIλDμ controller (MOFFOPID) for the speed control of EV systems with time-delay. It is presumed that while the EV is in movement, the armature winding resistance of the direct current (DC) motor varies...... controller. Finally, the experimental results based on a TMS320F28335 DSP are implemented on a DC motor to verify the effectiveness of the proposed MOFFOPID controller in controlling the speed of the DC motor which has non-linear features. The results of the simulation confirm the desirable performance...

  12. Dual Mode Vehicle with In-Wheel Motor: Regenerative Braking Optimization Véhicule bi-mode avec moteurs roues : optimisation du freinage récupératif

    Directory of Open Access Journals (Sweden)

    Le Solliec G.

    2013-03-01

    Full Text Available To meet the growing need for mobility of people and goods while massively reducing CO2 emissions, the electrification of vehicles is an essential solution. The variety of vehicles and their use results in innovative solutions for adapted architecture. This is especially true for light commercial vehicles where the objective is to promote full electric use in urban conditions (zero emission vehicle while maintaining significant range autonomy on road. The project VelRoue, a partnership between Renault, Michelin and IFP Energies nouvelles, aims to develop a dedicated dual-mode vehicle using a conventional thermal powertrain on the front axle and in-wheel motors on the rear one each powertrain to its use and makes it possible to achieve a low level of homologation CO2 emissions. In addition to features that meet the specific use of a commercial vehicle, in this paper we will particularly demonstrate the benefit of such an architecture to optimize the regenerative braking while ensuring a safe dynamic behaviour. Pour faire face au besoin croissant de mobilité des personnes et des biens tout en réduisant massivement les émissions de CO2, l’électrification des véhicules est une solution majeure. La grande variété des véhicules et de leur utilisation conduit à la mise en place d’architectures adaptées et donc de solutions innovantes. Cela est particulièrement le cas pour le développement de véhicules utilitaires dont l’objectif est de promouvoir un usage tout électrique en ville (véhicule zéro émission tout en maintenant une autonomie significative pour un usage extra-urbain. Le projet VelRoue, un partenariat entre Renault, Michelin et IFP Energies nouvelles, a pour objectif le développement d’un véhicule utilitaire bi-mode utilisant un groupe motopropulseur thermique traditionnel sur le train avant et des moteurs roues sur le train arrière. Chaque système de propulsion sera alors séparément optimisé à son utilisation

  13. In-Vehicle Dynamic Curve-Speed Warnings at High-Risk Rural Curves

    Science.gov (United States)

    2018-03-01

    Lane-departure crashes at horizontal curves represent a significant portion of fatal crashes on rural Minnesota roads. Because of this, solutions are needed to aid drivers in identifying upcoming curves and inform them of a safe speed at which they s...

  14. Brake fault diagnosis using Clonal Selection Classification Algorithm (CSCA – A statistical learning approach

    Directory of Open Access Journals (Sweden)

    R. Jegadeeshwaran

    2015-03-01

    Full Text Available In automobile, brake system is an essential part responsible for control of the vehicle. Any failure in the brake system impacts the vehicle's motion. It will generate frequent catastrophic effects on the vehicle cum passenger's safety. Thus the brake system plays a vital role in an automobile and hence condition monitoring of the brake system is essential. Vibration based condition monitoring using machine learning techniques are gaining momentum. This study is one such attempt to perform the condition monitoring of a hydraulic brake system through vibration analysis. In this research, the performance of a Clonal Selection Classification Algorithm (CSCA for brake fault diagnosis has been reported. A hydraulic brake system test rig was fabricated. Under good and faulty conditions of a brake system, the vibration signals were acquired using a piezoelectric transducer. The statistical parameters were extracted from the vibration signal. The best feature set was identified for classification using attribute evaluator. The selected features were then classified using CSCA. The classification accuracy of such artificial intelligence technique has been compared with other machine learning approaches and discussed. The Clonal Selection Classification Algorithm performs better and gives the maximum classification accuracy (96% for the fault diagnosis of a hydraulic brake system.

  15. NORMALIZATION OF AUTOMOTIVE BRAKE CHARACTERISTICS WHILE OPERATING THEM IN THE REPUBLIC OF BELARUS

    Directory of Open Access Journals (Sweden)

    I. M. Flerko

    2012-01-01

    Full Text Available Safety provision for the operated auto-transport facilities is of great significance all over the world. The problem is also considered as an actual one for the automotive transport of theRepublicofBelarus. Provision of higher brake system reliability for the operated vehicles is one of the directions to solve the problem pertaining to improve traffic safety.The paper contains an analysis of basic national standard documents which regulate brake characteristics for the operated vehicles, evaluates checking methods of braking efficiency and vehicle stability at the moment of braking, considers some problems pertaining to methods used for checking and estimation of braking control systems of transport facilities. 

  16. Semi-active H∞ control of high-speed railway vehicle suspension with magnetorheological dampers

    Science.gov (United States)

    Zong, Lu-Hang; Gong, Xing-Long; Xuan, Shou-Hu; Guo, Chao-Yang

    2013-05-01

    In this paper, semi-active H∞ control with magnetorheological (MR) dampers for railway vehicle suspension systems to improve the lateral ride quality is investigated. The proposed semi-active controller is composed of a H∞ controller as the system controller and an adaptive neuro-fuzzy inference system (ANFIS) inverse MR damper model as the damper controller. First, a 17-degree-of-freedom model for a full-scale railway vehicle is developed and the random track irregularities are modelled. Then a modified Bouc-Wen model is built to characterise the forward dynamic characteristics of the MR damper and an inverse MR damper model is built with the ANFIS technique. Furthermore, a H∞ controller composed of a yaw motion controller and a rolling pendulum motion (lateral motion+roll motion) controller is established. By integrating the H∞ controller with the ANFIS inverse model, a semi-active H∞ controller for the railway vehicle is finally proposed. Simulation results indicate that the proposed semi-active suspension system possesses better attenuation ability for the vibrations of the car body than the passive suspension system.

  17. The emergency braking module for an electronic copilot design and first results

    Energy Technology Data Exchange (ETDEWEB)

    Ameling, C.; Kirchner, A. [Univ. of the Federal Armed Forces Hamburg (Germany). Dept. of Mechanical Engineering

    2000-07-01

    This paper deals with design and development of an emergency braking module for an electronic copilot (ECP). ECP is used within an autonomous vehicle as a partial redundant system for vehicle control. ECP receives the necessary information about the positions and relative velocities of obstacles from various sources such as laserscanner or vision sensors. In the current stage of development the emergency breaking module computes, whether an object collides with the front of the vehicle. If the time-to-collision falls below the braking capacity an emergency braking is triggered. Experimental results show the capabilities of the system. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Xuedong Yan

    2016-06-01

    Full Text Available 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.

  19. EEG potentials predict upcoming emergency brakings during simulated driving

    Science.gov (United States)

    Haufe, Stefan; Treder, Matthias S.; Gugler, Manfred F.; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin

    2011-10-01

    Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h-1 driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.

  20. Development of combined brake system on front and rear brakes for scooter; Scooter yo zenkorin rendo brake system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Okazaki, Y; Itabashi, T; Shinohara, S; Honda, Y [Honda R and D Co. Ltd., Tokyo (Japan)

    1997-10-01

    Scooters need appropriate front and rear wheel braking power distribution and each of front and rear brakes have been operated using right and left levers. This time, a low cost brakes with cable type combined brake system for small size scooter and a brakes with hydraulic type combined brake system for middle size scooter have been developed to obtain appropriate front and rear wheel braking power distribution. Both systems use convenient left lever to operate. 3 refs., 9 figs., 1 tab.

  1. Application of a distributed systems architecture for increased speed in image processing on an autonomous ground vehicle

    Science.gov (United States)

    Wright, Adam A.; Momin, Orko; Shin, Young Ho; Shakya, Rahul; Nepal, Kumud; Ahlgren, David J.

    2010-01-01

    was established as the most reliable protocol after testing various options. Improvement can be made to the system by migrating more algorithms to the hardware based FPGA to further speed up the operations of the vehicle.

  2. Assessing the potential benefits of the motorcycle autonomous emergency braking using detailed crash reconstructions.

    Science.gov (United States)

    Savino, Giovanni; Giovannini, Federico; Baldanzini, Niccolò; Pierini, Marco; Rizzi, Matteo

    2013-01-01

    The aim of this study was to assess the feasibility and quantitative potential benefits of a motorcycle autonomous emergency braking (MAEB) system in fatal rear-end crashes. A further aim was to identify possible criticalities of this safety system in the field of powered 2-wheelers (PTWs; e.g., any additional risk introduced by the system itself). Seven relevant cases from the Swedish national in-depth fatal crash database were selected. All crashes involved car-following in which a non-anti-lock braking system (ABS)-equipped motorcycle was the bullet vehicle. Those crashes were reconstructed in a virtual environment with Prescan, simulating the road scenario, the vehicles involved, their precrash trajectories, ABS, and, alternatively, MAEB. The MAEB chosen as reference for the investigation was developed within the European Commission-funded Powered Two-Wheeler Integrated Safety (PISa) project and further detailed in later studies, with the addition of the ABS functionality. The boundary conditions of each simulation varied within a range compatible with the uncertainty of the in-depth data and also included a range of possible rider behaviors including the actual one. The benefits of the MAEB were evaluated by comparing the simulated impact speed in each configuration (no ABS/MAEB, ABS only, MAEB). The MAEB proved to be beneficial in a large number of cases. When applicable, the benefits of the system were in line with the expected values. When not applicable, there was no clear evidence of an increased risk for the rider due to the system. MAEB represents an innovative safety device in the field of PTWs, and the feasibility of such a system was investigated with promising results. Nevertheless, this technology is not mature yet for PTW application. Research in the field of passenger cars does not directly apply to PTWs because the activation logic of a braking system is more challenging on PTWs. The deployment of an autonomous deceleration would affect the

  3. Low speed hybrid generalized predictive control of a gasoline-propelled car.

    Science.gov (United States)

    Romero, M; de Madrid, A P; Mañoso, C; Milanés, V

    2015-07-01

    Low-speed driving in traffic jams causes significant pollution and wasted time for commuters. Additionally, from the passengers׳ standpoint, this is an uncomfortable, stressful and tedious scene that is suitable to be automated. The highly nonlinear dynamics of car engines at low-speed turn its automation in a complex problem that still remains as unsolved. Considering the hybrid nature of the vehicle longitudinal control at low-speed, constantly switching between throttle and brake pedal actions, hybrid control is a good candidate to solve this problem. This work presents the analytical formulation of a hybrid predictive controller for automated low-speed driving. It takes advantage of valuable characteristics supplied by predictive control strategies both for compensating un-modeled dynamics and for keeping passengers security and comfort analytically by means of the treatment of constraints. The proposed controller was implemented in a gas-propelled vehicle to experimentally validate the adopted solution. To this end, different scenarios were analyzed varying road layouts and vehicle speeds within a private test track. The production vehicle is a commercial Citroën C3 Pluriel which has been modified to automatically act over its throttle and brake pedals. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  4. A Microcontroller Based Car-Safety System Implementing Drowsiness Detection And Vehicle-Vehicle Distance Detection In Parallel.

    Directory of Open Access Journals (Sweden)

    Pragyaditya Das.

    2015-08-01

    Full Text Available Abstract Accidents due to drowsiness can be controlled and prevented with the help of eye blink sensor using IR rays. It consists of IR transmitter and an IR receiver. The transmitter transmits IR rays into the eye. If the eye is shut then the output is high. If the eye is open then the output is low. This output is interfaced with an alarm inside and outside the vehicle. This module can be connected to the braking system of the vehicle and can be used to reduce the speed of the vehicle. The alarm inside the vehicle will go on for a period of time until the driver is back to his senses. If the driver is unable to take control of the vehicle after that stipulated amount of time then the alarm outside the vehicle will go on to warn and tell others to help the driver.

  5. Applications of a saving method with max-min ant system to a vehicle routing problem with time windows and speed limits

    Directory of Open Access Journals (Sweden)

    Suphan Sodsoon

    2014-06-01

    Full Text Available This study aims to solve a Vehicle Routing Problem with Time Windows and Speed Limits (VRPTWSL, which has received considerable attention in recent years. The vehicle routing problem with time windows is an extension of the well-known Vehicle Routing Problem (VRP and involves a fleet of vehicles set of from a depot to serve a number of customers at different geographic locations with various demands within specific time and speed limits before returning to the depot eventually. To solve the problem, an efficient Saving Method-Max Min Ant System (Saving-MMAS with Local Search algorithm is applied. Using minimization of the total transportation costs as the objective of the extension VRPTWSL, a mathematic model is constructed. Finally, the Saving-MMAS algorithms indicated the good quality of the method in this problem.

  6. Study and performances analysis of fuel cell assisted vector control variable speed drive system used for electric vehicles

    Science.gov (United States)

    Pachauri, Rupendra Kumar; Chauhan, Yogesh K.

    2017-02-01

    This paper is a novel attempt to combine two important aspects of fuel cell (FC). First, it presents investigations on FC technology and its applications. A description of FC operating principles is followed by the comparative analysis of the present FC technologies together with the issues concerning various fuels. Second, this paper also proposes a model for the simulation and performances evaluation of a proton exchange membrane fuel cell (PEMFC) generation system. Furthermore, a MATLAB/Simulink-based dynamic model of PEMFC is developed and parameters of FC are so adjusted to emulate a commercially available PEMFC. The system results are obtained for the PEMFC-driven adjusted speed induction motor drive (ASIMD) system, normally used in electric vehicles and analysis is carried out for different operating conditions of FC and ASIMD system. The obtained results prove the validation of system concept and modelling.

  7. Development, Implementation and Evaluation of an Educational Intervention to Prevent Low Speed Vehicle Run-Over Events: Lessons Learned.

    Science.gov (United States)

    Griffin, Bronwyn; Watt, Kerrianne; Kimble, Roy; Shields, Linda

    2018-04-05

    There is a growing body of literature regarding low speed vehicle runover (LSVRO) events among children. To date, no literature exists on evaluation of interventions to address this serious childhood injury. Knowledge, attitudes, and behaviour regarding LSVROs were assessed via survey at a shopping centre (pre-intervention), then five months later (post-intervention), to investigate the effect of a population level educational intervention in Queensland, Australia. Participants' knowledge regarding frequency of LSVRO events was poor. No participant demonstrated 'adequate behaviour' in relation to four safe driveway behaviours pre-intervention; this increased at post-intervention ( p experience reflects the 'real-world' challenges associated with implementing prevention strategies. We suggest a multi-faceted approach involving media (including social media), legislative changes, subsidies (for reversing cameras), and education to prevent LSVROs.

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

    Science.gov (United States)

    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

  9. Validation of temporal and spatial consistency of facility- and speed-specific vehicle-specific power distributions for emission estimation: A case study in Beijing, China.

    Science.gov (United States)

    Zhai, Zhiqiang; Song, Guohua; Lu, Hongyu; He, Weinan; Yu, Lei

    2017-09-01

    Vehicle-specific power (VSP) has been found to be highly correlated with vehicle emissions. It is used in many studies on emission modeling such as the MOVES (Motor Vehicle Emissions Simulator) model. The existing studies develop specific VSP distributions (or OpMode distribution in MOVES) for different road types and various average speeds to represent the vehicle operating modes on road. However, it is still not clear if the facility- and speed-specific VSP distributions are consistent temporally and spatially. For instance, is it necessary to update periodically the database of the VSP distributions in the emission model? Are the VSP distributions developed in the city central business district (CBD) area applicable to its suburb area? In this context, this study examined the temporal and spatial consistency of the facility- and speed-specific VSP distributions in Beijing. The VSP distributions in different years and in different areas are developed, based on real-world vehicle activity data. The root mean square error (RMSE) is employed to quantify the difference between the VSP distributions. The maximum differences of the VSP distributions between different years and between different areas are approximately 20% of that between different road types. The analysis of the carbon dioxide (CO 2 ) emission factor indicates that the temporal and spatial differences of the VSP distributions have no significant impact on vehicle emission estimation, with relative error of less than 3%. The temporal and spatial differences have no significant impact on the development of the facility- and speed-specific VSP distributions for the vehicle emission estimation. The database of the specific VSP distributions in the VSP-based emission models can maintain in terms of time. Thus, it is unnecessary to update the database regularly, and it is reliable to use the history vehicle activity data to forecast the emissions in the future. In one city, the areas with less data can still

  10. The technology applying of inflatable devices to access adaptation, movement and landing descent vehicle from Martian environment to the Earth conditions

    Science.gov (United States)

    Koryanov, Vsevolod V.; Kazakovtsev, Victor P.

    2017-07-01

    At present, the idea has emerged to use special inflatable braking device (IBD) which permits to implement the landing vehicle (LV) "soft" landing on the planet's surface without a parachute system. Braking device (BD) unfolds still at the extra-atmospheric flight stage to provide the LV passive stabilisation, and the entire apparatus together with the braking device is twisted around its longitudinal axis. The advantage of an inflatable BD over traditional non-rigid brakes - parachutes is that it can be used at the atmospheric stage of the descent, starting from hypersonic speeds, and ending subsonic ones. These main theses are implemented in the project MetNet and its sequel project RITD, using Entry, Descent and Landing System (EDLS) system [1].

  11. Vehicle speed prediction via a sliding-window time series analysis and an evolutionary least learning machine: A case study on San Francisco urban roads

    Directory of Open Access Journals (Sweden)

    Ladan Mozaffari

    2015-06-01

    Full Text Available The main goal of the current study is to take advantage of advanced numerical and intelligent tools to predict the speed of a vehicle using time series. It is clear that the uncertainty caused by temporal behavior of the driver as well as various external disturbances on the road will affect the vehicle speed, and thus, the vehicle power demands. The prediction of upcoming power demands can be employed by the vehicle powertrain control systems to improve significantly the fuel economy and emission performance. Therefore, it is important to systems design engineers and automotive industrialists to develop efficient numerical tools to overcome the risk of unpredictability associated with the vehicle speed profile on roads. In this study, the authors propose an intelligent tool called evolutionary least learning machine (E-LLM to forecast the vehicle speed sequence. To have a practical evaluation regarding the efficacy of E-LLM, the authors use the driving data collected on the San Francisco urban roads by a private Honda Insight vehicle. The concept of sliding window time series (SWTS analysis is used to prepare the database for the speed forecasting process. To evaluate the performance of the proposed technique, a number of well-known approaches, such as auto regressive (AR method, back-propagation neural network (BPNN, evolutionary extreme learning machine (E-ELM, extreme learning machine (ELM, and radial basis function neural network (RBFNN, are considered. The performances of the rival methods are then compared in terms of the mean square error (MSE, root mean square error (RMSE, mean absolute percentage error (MAPE, median absolute percentage error (MDAPE, and absolute fraction of variances (R2 metrics. Through an exhaustive comparative study, the authors observed that E-LLM is a powerful tool for predicting the vehicle speed profiles. The outcomes of the current study can be of use for the engineers of automotive industry who have been

  12. Deployable Engine Air Brake

    Science.gov (United States)

    2014-01-01

    On approach, next-generation aircraft are likely to have airframe noise levels that are comparable to or in excess of engine noise. ATA Engineering, Inc. (ATA) is developing a novel quiet engine air brake (EAB), a device that generates "equivalent drag" within the engine through stream thrust reduction by creating a swirling outflow in the turbofan exhaust nozzle. Two Phase II projects were conducted to mature this technology: (1) a concept development program (CDP) and (2) a system development program (SDP).

  13. Schoolbus driver performance can be improved with driver training, safety incentivisation, and vehicle roadworthy modifications

    Directory of Open Access Journals (Sweden)

    A van Niekerk

    2017-03-01

    Full Text Available In South Africa (SA, the school transport industry provides millions of children with a means of travelling to and from school. The industry has, however, been reported to be plagued by widespread safety concerns. The consequent road traffic incidents have often been attributed to driver factors, including driving in excess of legal speeds or at inappropriate speeds; driving while under the influence of alcohol, while sleepy or fatigued; or driving without using protective equipment for vehicle occupants. There are currently very few SA interventions that specifically target this important industry role-player. The Safe Travel to School Programme was recently implemented by a national child safety agency, with a focus on driver road safety awareness, defensive driver training, eye- testing, vehicle roadworthy inspections with selected upgrades, incentives for safe performance, and implementation of a vehicle telematics tracking system with regular, individual driving behaviour information updates. This quasi-experimental study offers an evaluation of the initial impact on safety performance of this telematics-based driver and vehicle safety intervention in terms of speeding, acceleration, braking, cornering, and time-of-day driving, and compares the school transport driver performance with that of general motorists. Despite concerns that some school transport vehicles are used for multiple purposes outside of school transport duties, at night, and for longer distances, overall these vehicles recorded lower percentages of speeding, lower harsh braking, and lower average harsh cornering and acceleration than general drivers.

  14. Sprag solenoid brake. [development and operations of electrically controlled brake

    Science.gov (United States)

    Dane, D. H. (Inventor)

    1974-01-01

    The development and characteristics of an electrically operated brake are discussed. The action of the brake depends on energizing a solenoid which causes internally spaced sprockets to contact the inner surface of the housing. A spring forces the control member to move to the braking position when the electrical function is interrupted. A diagram of the device is provided and detailed operating principles are explained.

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

    Science.gov (United States)

    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.

  16. Hydraulic brake-system for a bicycle

    NARCIS (Netherlands)

    Van Frankenhuyzen, J.

    2007-01-01

    The invention relates to a hydraulic brake system for a bicycle which may or may not be provided with an auxiliary motor, comprising a brake disc and brake claws cooperating with the brake disc, as well as fluid-containing channels (4,6) that extend between an operating organ (1) and the brake

  17. RESEARCH OF VEHICLE’S BRAKING DYNAMICS AT TRAFFIC ACCIDENT ANALYSIS

    Directory of Open Access Journals (Sweden)

    A. Turenko

    2010-01-01

    Full Text Available The problem of vehicles braking process after the road accident is reviewed. The inaccuracies are analyzed for the purpose of deceleration determination occurance at the application of out-of-date statistical database by experts.

  18. Design and Simulation of the Robust ABS and ESP Fuzzy Logic Controller on the Complex Braking Maneuvers

    Directory of Open Access Journals (Sweden)

    Andrei Aksjonov

    2016-11-01

    Full Text Available Automotive driving safety systems such as an anti-lock braking system (ABS and an electronic stability program (ESP assist drivers in controlling the vehicle to avoid road accidents. In this paper, ABS and the ESP, based on the fuzzy logic theory, are integrated for vehicle stability control in complex braking maneuvers. The proposed control algorithm is implemented for a sport utility vehicle (SUV and investigated for braking on different surfaces. The results obtained for the vehicle software simulator confirm the robustness of the developed control strategy for a variety of road profiles and surfaces.

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

    Science.gov (United States)

    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

  20. Advanced Emergency Braking Controller Design for Pedestrian Protection Oriented Automotive Collision Avoidance System

    OpenAIRE

    Lie, Guo; Zejian, Ren; Pingshu, Ge; Jing, Chang

    2014-01-01

    Automotive collision avoidance system, which aims to enhance the active safety of the vehicle, has become a hot research topic in recent years. However, most of the current systems ignore the active protection of pedestrian and other vulnerable groups in the transportation system. An advanced emergency braking control system is studied by taking into account the pedestrians and the vehicles. Three typical braking scenarios are defined and the safety situations are assessed by comparing the cu...