WorldWideScience

Sample records for antilock brake systems

  1. 49 CFR 393.55 - Antilock brake systems.

    Science.gov (United States)

    2010-10-01

    ... Motor Vehicle Safety Standard (FMVSS) No. 105 (49 CFR 571.105, S5.5). (b) ABS malfunction indicators for... with an antilock brake system that meets the requirements of FMVSS No. 121 (49 CFR 571.121, S5.1.6.1(b... equipped with an antilock brake system that meets the requirements of FMVSS No. 121 (49 CFR 571.121,...

  2. Linear Control Technique for Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    Chankit Jain

    2014-08-01

    Full Text Available Antilock braking systems are used in modern cars to prevent the wheels from locking after brakes are applied. The dynamics of the controller needed for antilock braking system depends on various factors. The vehicle model often is in nonlinear form. Controller needs to provide a controlled torque necessary to maintain optimum value of the wheel slip ratio. The slip ratio is represented in terms of vehicle speed and wheel rotation. In present work first of all system dynamic equations are explained and a slip ratio is expressed in terms of system variables namely vehicle linear velocity and angular velocity of the wheel. By applying a bias braking force system, response is obtained using Simulink models. Using the linear control strategies like PI-type the effectiveness of maintaining desired slip ratio is tested. It is always observed that a steady state error of 10% occurring in all the control system models.

  3. Dynamic Control Applied to a Laboratory Antilock Braking System

    Directory of Open Access Journals (Sweden)

    Cuauhtémoc Acosta Lúa

    2015-01-01

    Full Text Available The control of an antilock braking system is a difficult problem due to the existence of nonlinear dynamics and uncertainties of its characteristics. To overcome these issues, in this work, a dynamic nonlinear controller is proposed, based on a nonlinear observer. To evaluate its performance, this controller has been implemented on an ABS Laboratory setup, representing a quarter car model. The nonlinear observer reconstructs some of the state variables of the setup, assumed not measurable, to establish a fair benchmark for an ABS system of a real automobile. The dynamic controller ensures exponential convergence of the state estimation, as well as robustness with respect to parameter variations.

  4. The influence of various pressures in pneumatic tyre on braking process of car with anti-lock braking system

    Directory of Open Access Journals (Sweden)

    Damian HADRYŚ

    2008-01-01

    Full Text Available In this article has been presented the influence of various pressures inpneumatic tyre of passenger car Fiat Panda 1.3 JTD with anti-lock braking system on chosen parameters of braking process: course of braking deceleration, maximum value of deceleration, braking distances.

  5. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    Science.gov (United States)

    Wibowo, Zakaria, Lambang, Lullus; Triyono, Muhayat, Nurul

    2016-03-01

    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.

  6. Digital Sliding Mode Control of Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    MITIC, D. B.

    2013-02-01

    Full Text Available The control of anti-lock braking system is a great challenge, because of the nonlinear and complex characteristics of braking dynamics, unknown parameters of vehicle environment and system parameter variations. Using some of robust control methods, such as sliding mode control, can be a right solution for these problems. In this paper, we introduce a novel approach to design of ABS controllers, which is based on digital sliding mode control with only input/output measurements. The relay term of the proposed digital sliding mode control is filtered through digital integrator, reducing the chattering phenomenon in that way, and the additional signal of estimated modelling error is introduced into control algorithm to enhance the system steady-state accuracy. The given solution was verified in real experimental framework and the obtained results were compared with the results of implementation of two other digital sliding mode control algorithms. It is shown that it gives better system response, higher steady-state accuracy and smaller chattering.

  7. 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.

  8. INVESTIGATION OF ANTILOCK BRAKE SYSTEM EFFECT ON PASSENGER CAR BRAFKING EFFICIENCY

    Directory of Open Access Journals (Sweden)

    I. Davidenko

    2011-01-01

    Full Text Available It has been experimentally proved that in case of emergency braking the constant decelera-tion of passenger cars equipped by antilock brake system exceeds the tabulated statistical data by 7,7–17 % that is recommended to apply at technical expertise at traffic accident causes investigation.

  9. Design and Analysis of Electro-mechanical Hybrid Anti-lock Braking System for Hybrid Electric Vehicle Utilizing Motor Regenerative Braking

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jianlong; YIN Chengliang; ZHANG Jianwu

    2009-01-01

    Braking on low adhesion-coefficient roads, hybrid electric vehicle's motor regenerative torque is switched off to safeguard the normal anti-lock braking system (ABS) function. When the ABS control is terminated, the motor regenerative braking is readmitted.Aiming at avoiding permanent cycles from hydraulic anti-lock braking to motor regenerative braking, a novel electro-mechanical hybrid anti-lock braking system using fuzzy logic is designed. Different from the traditional single control structure, this system has a two-layered hierarchical structure. The first layer is responsible for harmonious adjustment or interaction between regenerative system and anti-lock braking system. The second layer is responsible for braking torque distribution and adjustment. The closed-loop simulation model is built. Control strategy and method for coordination between regenerative and anti-lock braking are developed. Simulation braking on low adhesion-coefficient roads with fuzzy logic control and real vehicle braking field test are presented. The results from simulating analysis and experiment show braking performance of the vehicle is perfect, harmonious coordination between regenerative and anti-lock braking function, significant amount of braking energy can be recovered and the proposed control strategy and method are effective.

  10. Hardware-in-the-loop of Simulation for a Hydraulic Antilock Brake System

    OpenAIRE

    Ayman A. Aly

    2013-01-01

    Hardware-In-the-Loop (HIL) of simulation policy is used as a rapid and economical tool for developing automotive systems effectively and for dangerous situations tests such as extreme road conditions or high travelling speeds. A method for building a HIL of simulation a hydraulic Antilock Braking System (ABS) based on MATLAB/Simulink is presented in this paper. The system is implemented for research purposes as well as for the application in educational process. It can help the user heighteni...

  11. Road Identification for Anti-Lock Brake Systems Equipped with Only Wheel Speed Sensors

    Institute of Scientific and Technical Information of China (English)

    吴卫东; 尹用山

    2001-01-01

    Anti-lock brake systems (ABS) are now widely used on motor vehicles. To reduce product cost andto use currently available technologies, standard ABS uses only wheel speed sensors to detect wheel angularvelocities, which is not enough to directly obtain wheel slip ratios needed by the control unit, but can be usedto calculate reference slip ratios with measured wheel angular velocities and the estimated vehicle speed.Therefore, the road friction coefficient, which determines the vehicle deceleration during severe braking, is animportant parameter in estimating vehicle speed. This paper analyzes wheel acceleration responses insimulations of severe braking on different road surfaces and selects a pair of specific points to identify thewheel acceleration curve for each operating condition, such as road surface, pedal-braking torque and wheelvertical load. It was found that the curve using the selected points for each road surface clearly differs fromthat of the other road surfaces. Therefore, different road surfaces can be distinguished with these selectedpoints which represent their corresponding road surfaces. The analysis assumes that only wheel speed sensorsare available as hardware and that the road cohesion condition can be determined in the initial part of thesevere braking process.``

  12. Asymmetric Barrier Lyapunov Function-Based Wheel Slip Control for Antilock Braking System

    Directory of Open Access Journals (Sweden)

    Xiaolei Chen

    2015-01-01

    Full Text Available As an important device of the aircraft landing system, the antilock braking system (ABS has a function to avoid aircraft wheels self-locking. To deal with the strong nonlinear characteristics, complex nonlinear control schemes are applied in ABS. However, none of existing control schemes focus on the braking operating status, which directly reflects wheels self-locking degree. In this paper, the braking operating status region is divided into three regions: the healthy region, the light slip region, and the deep slip region. An ABLF-based wheel slip controller is proposed for ABS to constrain the braking system operating status in the healthy region and the light slip region. Therefore the ABS will be prevented from operating in the deep slip region. Under the proposed control scheme, self-locking is avoided completely and zero steady state error tracking of the wheel optimal slip ratio is implemented. The Hardware-In-Loop (HIL experiments have validated the effectiveness of the proposed controller.

  13. New Method of Road Surface Identification in Anti-Lock Braking System

    Institute of Scientific and Technical Information of China (English)

    QI Zhi-quan; LIU Zhao-du; ZHANG Jing-bo; MA Yue-feng

    2005-01-01

    Based on the vehicle-road dynamic model, the road characteristic parameter, which depends on different types of road surfaces, is introduced and a new method of road surface identification for automotive anti-lock braking system (ABS) is proposed. According to the characteristics of vehicle-road dynamic model, a simple math resolution method of the model's factors is established. Only using the information of wheel speed, the vehicle reference velocity and the wheel slip ratio are estimated real-timely. And based on the wheel dynamic model, the road characteristic parameter is determined to identify the road surface for the determination of thresholds of ABS regulative parameters. With this new method, the road surface identification can be accurately obtained and calculation time is short that it can meet the ABS real time control need, and it also improves the performance of ABS.

  14. The effectiveness of antilock braking systems in reducing accidents in Great Britain.

    Science.gov (United States)

    Broughton, Jeremy; Baughan, Chris

    2002-05-01

    Antilock braking systems (ABS) are fitted to many new cars with the aims of improving their ability to steer while braking heavily and of reducing stopping distances on some road surfaces. This paper presents the findings of a project that assessed the effectiveness of ABS in reducing accidents in Great Britain. A large postal survey was carried out of the owners of modern cars. asking for details of any accidents in which they had been involved during the previous year as well as factors that might influence their likelihood of being involved in an accident. Questions were also asked to test respondents' knowledge of ABS. ABS cars ditfered in several respects from non-ABS cars, as did the two groups of drivers. Consequently, a sophisticated statistical analysis was required to provide unbiased estimates of the effectiveness of ABS. Various results did not achieve statistical significance, but the overall stability of the results indicates that real effects have been measured. They confirm that ABS does have the potential to reduce the number of accidents, but show that this has not been fully achieved. One reason may be that many drivers have little or no knowledge of ABS.

  15. 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…

  16. Dynamic analysis and control of an anti-lock brake system for a motorcycle with a camber angle

    Science.gov (United States)

    Huang, C. K.; Shih, M. C.

    2011-04-01

    This paper analyses the dynamic response of a motorcycle with an anti-lock brake system (ABS) and camber or steering angle. Most studies have assumed that motorcycles brake in a straight line - that is, without a steering or camber angle. In this work, the performance of an ABS modulator is designed and analysed at first. Then, a controller is designed for motorcycle turning. The controller uses angular acceleration and the pressure value in brake calipers on the front and rear wheels, camber angle and lateral acceleration as commands to control brake pressure on each wheel to prevent wheel locking. The equation of motion for a motorcycle is based on Weir's equations. This motorcycle model combines a mathematical equation of the ABS modulator, tyre model and controller in simulations.

  17. The Development of a Fuzzy Predictive Control System for Automotive Anti-lock Braking System

    Institute of Scientific and Technical Information of China (English)

    HUANGFU Shihui; BAO Xiangying

    2006-01-01

    This paper presents the model of one-tire kinetics、tires、the braking system and the model of control system. On virtual road, this paper builds a fuzzy predictive control system to insure the best attachment coefficient between tires and road. And it turns out to be that this fuzzy predictive control method has achieved good performances.

  18. On Maintenance of Electronic Anti-lock Braking System (ABS)%电控防抱死制动系统(ABS)的检修

    Institute of Scientific and Technical Information of China (English)

    吴继刚

    2015-01-01

    随着汽车制动系统技术的不断改进,电控防抱死ABS系统已逐渐成为汽车的标准配件,了解电控防抱死ABS系统的维修技术对汽车制动系统的维修和故障诊断工作十分重要.ABS主要部件的检修包括:ABS ECU的检修、轮速传感器的检修、液压控制装置的检修、制动压力调节器的检修.%With the continuous improvement of technology related to automobile braking system,electronic anti-lock ABS system has gradually become one of the standard fittings of automobile,to learn maintenance technology related to electronic anti-lock ABS system is of great importance to maintain and fault diagnosing of automobile braking system.The maintenance for main components of ABS includes the maintenance for ABS ECU,wheel speed sensor,hydraulic controlled devices,braking pressure regulator,etc.

  19. Development and Verification of the Tire/Road Friction Estimation Algorithm for Antilock Braking System

    Directory of Open Access Journals (Sweden)

    Jian Zhao

    2014-01-01

    Full Text Available Road friction information is very important for vehicle active braking control systems such as ABS, ASR, or ESP. It is not easy to estimate the tire/road friction forces and coefficient accurately because of the nonlinear system, parameters uncertainties, and signal noises. In this paper, a robust and effective tire/road friction estimation algorithm for ABS is proposed, and its performance is further discussed by simulation and experiment. The tire forces were observed by the discrete Kalman filter, and the road friction coefficient was estimated by the recursive least square method consequently. Then, the proposed algorithm was analysed and verified by simulation and road test. A sliding mode based ABS with smooth wheel slip ratio control and a threshold based ABS by pulse pressure control with significant fluctuations were used for the simulation. Finally, road tests were carried out in both winter and summer by the car equipped with the same threshold based ABS, and the algorithm was evaluated on different road surfaces. The results show that the proposed algorithm can identify the variation of road conditions with considerable accuracy and response speed.

  20. 汽车转向防抱死制动控制系统研究%Research on steering antilock braking control system for vehicles.

    Institute of Scientific and Technical Information of China (English)

    李果; 刘华伟

    2012-01-01

    为了研究解决车辆转向过程中防抱死制动稳定性问题,设计了一种由执行级、协调级组成的分层控制系统,在执行级,设计了基于遗传算法的汽车ABS最优滑模控制器;设计了基于遗传算法的汽车转向滑模控制器.在协调级,针对制动和转向两个子系统提出协调控制方案,给出具体协调策略.用仿真结果验证所设计控制算法的稳定性和有效性.%It is to study a new hierarchical intelligent control system in the vehicle's steering antilock brake stability fields. A layered control system consisting of the execution layer and the cooperation layer is designed. On the execution layer, optimal sliding mode controller based on genetic algorithms is designed for the automotive brake controller. Optimal sliding mode controller based on genetic algorithms is designed for the automotive steering controller. On the cooperation layer, this paper provides coordination control scheme and gives a specific coordination strategy for two subsystem of braking and steering. The stability and the validity of the control algorithm are validated by simulation results.

  1. 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.

  2. 浅谈汽车防抱死系统结构原理及故障检测%Structural Principle and Fault Detection of Anti-lock Brake System

    Institute of Scientific and Technical Information of China (English)

    郭友学; 李江江

    2013-01-01

    现如今汽车防抱死系统(ABS)已作为大多数中高档轿车的标准配置,配备该系统将会显著改善汽车制动性和操纵稳定性,本文将针对常见ABS系统的结构、原理及常见故障检测方法做简单介绍.%With the anti-lock brake system (ABS) significantly improve vehicle braking and handling stability, it have been used in the standard configuration of most luxury cars now. This article will focus on the common structure of the ABS system, the principle and common fault detection methods.

  3. Simulation of Semi-trailer Train Anti-lock Braking System Based on Matlab/Simulink%基于Matlab/Simulink的半挂汽车列车防抱死制动系统仿真研究

    Institute of Scientific and Technical Information of China (English)

    王立平; 李守成; 刘英杰

    2011-01-01

    The paper establishes a semi-trailer model and simulation for ABS application including body model,tire model,PID controller model,barometric system model and slip ratio model.The mathematical model of ABS system is simulated,and simulation curves are obtained on dry,wet and ice pavements.The simulation results show that the mathematical model is reliable;its braking performance is good;and the anti-lock braking system has an excellent braking performance and direction maneuver ability.%以半挂汽车列车为研究对象,建立整车数学模型、轮胎模型、PID控制器模型、气压系统模型和滑移率的计算模型。对所建立的半挂汽车列车防抱死制动系统数学模型进行仿真研究,得出在干路面、湿路面和冰路面上的仿真曲线。仿真结果表明,建立的防抱死制动系统数学模型可靠,能达到较为理想的制动控制效果,验证了半挂汽车列车防抱死制动系统具有良好的制动性能和方向操纵性。

  4. An Exploration of the Offset Hypothesis Using Disaggregate Data:The Case of Airbags and Antilock Brakes

    OpenAIRE

    Maheshri, Vikram; Mannering, Fred; Winston, Clifford

    2006-01-01

    The offset hypothesis predicts consumers adapt to innovations that improve safety by becoming less vigilant about safety. Previous tests have used aggregate data that may confound the effect of a safety policy with those consumers who are most affected by it. We test the hypothesis using disaggregate data to analyze the effects of airbags and antilock brakes on automobile safety. We find that safety-conscious drivers are more likely than other drivers to acquire airbags and antilock brakes bu...

  5. 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...

  6. 汽车防抱死制动系统方向稳定性控制方法%Control Method of Vehicle Directional Stability for Automobile Anti-lock Braking System

    Institute of Scientific and Technical Information of China (English)

    郑太雄; 马付雷; 杨勇

    2014-01-01

    In order to maintain vehicle directional stability during the emergency braking,a control method of controlling the brake wheel cylinder pressure difference between the front wheels was put forward. The control process of the anti-lock braking system (ABS)is divided into first control and conventional control. In the first control,the rotational speed difference between front wheels is used to identify the road condition provided that the front wheels are not locking. According to the identification result,the conventional control adopts the method of synchronous pressurization for the front wheels and independent control for the rear wheels on single cohesion coefficient roads,and adopts modified low selector control for front wheels and independent control for the rear wheels on split cohesion coefficient roads. In addition,according to the test methods and procedure specified by the national standards,braking tests were carried out on four typical roads in a test field. The steering correction angle of the vehicle during the tests was less than 30° within 2 s,much less than the 120° in national standards,which shows the effectiveness of the control method.%为了保持汽车紧急制动时的方向稳定性,提出了控制前轮制动轮缸压力差的控制方法。将防抱死制动系统的控制过程分为首次控制和常规控制,首次控制在保证车轮不抱死的情况下,利用前轴两侧轮速差辨识路面;常规控制根据辨识结果,在单一附着系数路面下采用前轮增压同步控制,后轮独立控制,在分离附着系数路面下采用前轮修正低选控制,后轮独立控制。根据国家标准规定试验方法和流程,在试车场进行了4种典型路面上的制动试验,试验过程中车辆的方向盘修正角在2 s内均小于30°,远小于国家标准规定的120°,表明了控制方法的有效性。

  7. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Science.gov (United States)

    2010-10-01

    ... systems. S1. Scope. This standard specifies requirements for hydraulic and electric service brake systems... braking performance under normal and emergency conditions. S3. Application. This standard applies to multi... are equipped with hydraulic or electric brake systems. S4. Definitions. Antilock brake system or...

  8. 基于Simulink的汽车ABS建模与仿真%Modeling and Simulation of the Anti-Lock Braking System based on Simulink

    Institute of Scientific and Technical Information of China (English)

    付建国; 王洪亮; 钟明利; 刘小芳

    2014-01-01

    The article illustrates Control the ABS Slip Ratio with Simulink, creates a single wheel ABS model according to the ABS principle. It produces Simulation curves,which verifies that the Auto ABS has good braking performance.%本文阐述了在Simulink的环境下以ABS(防抱死制动系统)滑移率为对象进行控制,根据ABS系统工作原理建立了ABS单一车轮的仿真模型,并得出仿真曲线,验证汽车ABS具有良好的制动性能。

  9. Negative Effect of Disc Thickness Variation on the Performance of Anti-lock Braking System and Its Control Method%制动盘厚薄差对ABS性能的负面影响及控制方法

    Institute of Scientific and Technical Information of China (English)

    张立军; 黄平宇

    2013-01-01

    A nonlinear braking dynamics model for a quarter car is established, which consists of a rigid-ring-based transient tire model and a disc brake model with consideration of disc thickness variation ( DTV). Based on the model and by using MATLAB/Simulink, the negative effects of DTV on the braking performance of ABS system with slip rate threshold control are analyzed, and a set of adaptive control parameters based on the degrees of DTV are proposed on the basis of optimization to suppress the negative effects of DTV. The results indicate that DTV has negative effects on wheel motion, braking performance and braking comfort, while the use of DTV adaptive control parameters though may deteriorate braking comfort, but can effectively improve wheel motion and braking performance.%建立了包含瞬态刚性圈轮胎模型、考虑制动盘厚薄差(DTV)的制动器模型的1/4车非线性制动动力学模型.基于该模型,利用MATLAB/Simulink软件分析了DTV对滑移率门限值控制下ABS制动性能的负面影响,并提出了一套抑制DTV影响的适应性控制参数.结果表明:DTV会对车轮运动状态、制动效能和制动舒适性产生负面影响,而采用DTV适应性ABS控制参数虽会恶化舒适性,但可改善车轮运动状态,提高制动效能.

  10. Simulation research of the auto anti-lock braking system based on simulink%基于simulink的汽车防抱死制动系统的仿真研究

    Institute of Scientific and Technical Information of China (English)

    李少廷; 徐家川

    2016-01-01

    在 simulink环境下对汽车防抱死制动系统进行数学建模,采用基于车轮加、减速度门限值及参考滑移率的控制策略,控制器以车轮的角加、减速度和滑移率的大小为输入,根据输入值的大小控制器输出相应的信号给制动模型,进而对轮速和滑移率进行调节,使其在理想范围内。对汽车ABS模型进行仿真研究,通过得出的仿真曲线,验证了 ABS 制动系统拥有良好的制动性和操纵性。%Mathematical modeling to the automotive anti-look braking system was built based on simulink.It adopted the wheel add,substract speed threshold method and referenced slip ratio control strategy.The size of the wheel angular velocity and slip ratio study were input into the controler,the corresponding signal was output to the model of the brake based on the size of the input value to adj ust the wheel speed and slip ratio.Simulation was carried out on the automobile ABS model and simulation curve was obtained.The results confirmed that the ABS braking sys-tem has good brake and maneuverability.

  11. 汽车主动悬架与制动防抱死系统集成控制研究%Research on the integrated control of the active suspension and anti-lock braking system

    Institute of Scientific and Technical Information of China (English)

    陈灿波

    2015-01-01

    在7自由度半车模型的基础上,建立主动悬架和制动防抱死系统集成控制器. 仿真分析表明,所建立的集成控制器不仅减小了制动时间和制动距离,提高了车辆的制动安全性,还可以有效减小车身在制动过程中产生的俯仰运动,改善了制动时的乘坐舒适性.%On the basis of the 7 degree of freedom half vehicle model , it establishes the integrated controller of active suspension and braking system .Simulation results show that the integrated controller can not only decrease the braking time and distance , improve the security of vehicle braking , but also effectively reduce the body pitching motion , improve the ride comfort .

  12. 75 FR 51521 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness...

    Science.gov (United States)

    2010-08-20

    ... involvements of hitting animals, pedestrians, or bicycles and, only in fatal crashes, rear-ending lead vehicles... Expenses for the Anti-Lock Brake System and Underride Guard for Tractors and Trailers (74 FR 18803... is no limit on the length of the attachments. Anyone is able to search the electronic form of...

  13. Bench testing technology of automobile anti-lock braking performance%汽车防抱死制动性能台架测试技术

    Institute of Scientific and Technical Information of China (English)

    周凯; 王旭东; 焦文良; 谭天江; 张焱

    2013-01-01

    For the problem that friction coefficient could not change fast between tire and road surface during the process of traditional road test and bench test of anti-lock braking system,a bench test method of automobile braking performance was brought forward according to the characteristics of the ABS control algorithm.The translational kinetic energy of vehicle was replaced by the rotational kinetic energy of flywheels which could determine the rotation inertia simulation method.The adhesion coefficient between tire and road surface could be realized by the slip between master-slave shafts of the magnetic powder clutch.Analysis results show that the test system can realize single adhesive coefficient road surface,reciprocal adhesive coefficient road surface and docking adhesive coefficient road surface.The test system can make performance evaluation to road condition recognition ability and dynamic response.%针对汽车防抱死刹车系统(ABS)在传统路试及台架测试过程中无法快速改变轮胎与路面间摩擦系数的问题,结合ABS控制算法的特点提出一种能够模拟不同路况组合的汽车ABS动态性能台架测试方法.利用4组飞轮在旋转时所具有的转动动能来等效实际被测车辆在此速度下的平动动能,确定转动惯量模拟方法.通过磁粉离合器主、从动轴之间的滑差实现轮胎与路面间摩擦系数的模拟.分析结果表明,测试系统能够完成单一附着系数路面、对开附着系数路面及对接附着系数路面的测试.测试系统能够对ABS控制逻辑中路面识别能力及其动态响应性能做出评价.

  14. 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.

  15. 49 CFR 238.431 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... brake system shall be designed to prevent thermal damage to wheels and brake discs. The operating... thermal damage to wheels or discs. (f) The brake system design shall allow a disabled train's pneumatic... a brake rate consistent with prevailing adhesion, passenger safety, and brake system...

  16. 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.

  17. 49 CFR 238.231 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... adhesion, passenger safety, and brake system thermal capacity. An emergency brake application shall be... are free of condemnable cracks. (g) Disc brakes shall be designed and operated to produce a surface... operating conditions; and (4) Operation of the friction brake alone does not result in thermal damage...

  18. 14 CFR 25.735 - Brakes and braking systems.

    Science.gov (United States)

    2010-01-01

    ... constructed so that: (1) If any electrical, pneumatic, hydraulic, or mechanical connecting or transmitting element fails, or if any single source of hydraulic or other brake operating energy supply is lost, it is... hydraulic system following a failure in, or in the vicinity of, the brakes is insufficient to cause...

  19. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  20. 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.

  1. Frictional couplings of wheel with a rail in a brake control system of rail vehicles

    Directory of Open Access Journals (Sweden)

    A. Baier

    2011-06-01

    Full Text Available Purpose: Discussion on use of frictional coupling of wheel with a rail for detection of surface condition of track ways in coal mine undergrounds is the paper objective.Design/methodology/approach: The method for detection of surface condition of track ways is based on using of dedicated converter installed on the locomotive chassis with active part in a form of “tracking wheel” that moves on the rail surface together with the locomotive. The converter is equipped with a system for torque load and a sensor measuring its rotational speed. Change of track surface is determined by momentary changes in rotational speed of “tracking wheel” due to its slippage.Findings: The described method for detection of track ways surface condition enables to generate information signal which transferred to master braking control system of the locomotive eliminates excessive slippage during braking.Research limitations/implications: The presented results confirm rightness of accepted method for detection of track ways surface condition indicating for necessity of modification of developed test rig to get repeatable information about current track surface.Originality/value: The method for detection of track ways surface condition is the novelty approach to braking of rail locomotives used in the mining industry. It is also an alternative option to the present solutions based on known ABS (Anti-Lock Braking System system used in automotive industry.

  2. 49 CFR 570.55 - Hydraulic brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles with hydraulic brake systems. (a) Brake system failure indicator. The hydraulic brake system failure...

  3. Operation peculiarities of airplane brake systems

    Directory of Open Access Journals (Sweden)

    В. Г. Докучаев

    1999-09-01

    Full Text Available Analyzed is the loading of airplane brake systems. Complex methods are proposed for investi­gation of highly loaded brake systems. The results of investigation of the influence of various factors on technical condition of friction units are given

  4. THE DEVELOPMENT OF TROLLEYBUS DRIVE BRAKE SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. Safonau

    2011-01-01

    Full Text Available The requirements for trolleybuses brake systems are analyzed. Some results of the studies examined, contemporary trends of developing in this direction are shows. The range of problems whose solution is aimed at creating high-performance brake systems whose increase efficiency and safety of trolleybuses determined.

  5. An Experimental Analysis of Brake Efficiency Using four Fluids in a Disc Brake System

    Directory of Open Access Journals (Sweden)

    Seth Daniel Oduro

    2013-02-01

    Full Text Available The paper studies disc brake failure in Mini-buses using an experimental analysis to test the maximum braking force when different brake fluids such as clean, less dirty, dirty and soapy water solution were used in the braking system. The experimental results clearly showed that the soap solution appears to be the best fluid as far as low viscosity and stability of viscosity with increase in temperature are concerned. However, the soap solution is not compatible with other fluid which makes it difficult to be substitute as a clean brake fluid. The result of the Thepra Universal Brake Testing Equipment used for the braking efficiency test indicated that a pedal brake of 117 kN produce a brake force of 0.96 kN for clean brake fluid, 0.91 kN for the less dirty, 0.85 kN for dirty and 1.44 kN for soap solution. The value of 1.44 kN which was achieved when the soap solution was used indicated a positive braking force and the indicating that soap solution could be used to produce a high pedal force within a very short time (about 10-30 min and can therefore be used only in case of emergency. The brake efficiency test indicated that under hot conditions the braking efficiency is reduced and the presence of air in the system renders the braking ineffective because higher pedal force was needed to be able to produce a significant braking force which is noted for causing brake failure.

  6. 制动防抱死工况制动器热机耦合特性仿真分析%Computational Investigation into Thermal-mechanical Coupling Characteristics of Disc Brake under Anti-lock Braking Condition

    Institute of Scientific and Technical Information of China (English)

    张立军; 何臻; 孟德建

    2016-01-01

    制动工况对制动器的热机耦合特性具有重要影响.建立了三自由度汽车制动动力学模型,制动力由采用滑移率逻辑门限值控制策略的制动防抱死系统(ABS,Anti-lock Brake System)控制,对干路面和湿路面的制动防抱死工况仿真,同时对相应路面非制动防抱死工况仿真,用于比较分析;建立通风盘式制动器热机耦合有限元动力学模型,对不同制动工况制动盘和制动块的热机耦合特性进行仿真,分析了制动防抱死工况制动器热机耦合特性,并通过与非制动防抱死工况比较,探究ABS对制动器热机耦合特性影响.经分析发现,制动防抱死系统引起的制动压力变化以及制动摩擦热功率改变将对热机耦合特性各个指标产生影响.

  7. Nonlinear Coupling Characteristics Analysis of Integrated System of Electromagnetic Brake and Frictional Brake of Car

    Directory of Open Access Journals (Sweden)

    Ren He

    2015-01-01

    Full Text Available Since theoretical guidance is lacking in the design and control of the integrated system of electromagnetic brake and frictional brake, this paper aims to solve this problem and explores the nonlinear coupling characteristics and dynamic characteristics of the integrated system of electromagnetic brake and frictional brake. This paper uses the power bond graph method to establish nonlinear coupling mathematical model of the integrated system of electromagnetic brake and frictional brake and conducts the contrastive analysis on the dynamic characteristics based on this mathematical model. Meanwhile, the accuracy of the nonlinear coupling mathematical model proposed above is verified on the hardware in the loop simulation platform, and nonlinear coupling characteristics of the integrated system are also analyzed through experiments.

  8. An Experimental Analysis of Brake Efficiency Using Four Fluids in a Drum Brake System

    Directory of Open Access Journals (Sweden)

    Prince Owusu-Ansah

    2014-06-01

    Full Text Available This paper studies drum brake failure in Mini-buses using an experimental analysis to test the viscosities and the maximum braking force when different fluids such as clean, less dirty, dirty and soapy water solution were used in the braking system. The effects of each of these fluids when successive increments in pedal force were applied at hot and cold conditions for drum brakes were studied. The results of the Thepra Universal Brake Testing Equipment used for the braking efficiency test indicated that a pedal force of 110 kN produce a brake force of 0.61 kN for clean fluid, 0.56 kN for less dirty, 0.51 kN for dirty and 0.92 kN. The value of 0.92 kN which was achieved when the soapy water solution was used indicated a positive braking force and that soap water solution could be used to produce a high pedal force within a very short time (10-30 min and can therefore be used only in case of emergency. It was observed that the clean brake fluid gave the best braking force followed by the less dirty and finally the dirty brake fluid. In a situation where air has been trapped in the system under hot condition with or without a servo unit, clean brake fluid performed much better at least three times better than the other three fluids. For soap solution, braking was effective only when it was operated at cold condition but less effective when the system was hot. Soap solution is therefore not reliable when used for a very long time but effective only for emergency situations.

  9. Modeling of a Hydraulic Braking System

    OpenAIRE

    Lundin, Christopher

    2015-01-01

    The objective of this thesis is to derive an analytical model representing a reduced form of a mine hoist hydraulic braking system. Based primarily on fluid mechanical and mechanical physical modeling, along with a number of simplifying assumptions, the analytical model will be derived and expressed in the form of a system of differential equations including a set of static functions. The obtained model will be suitable for basic simulation and analysis of system dynamics, with the aim to cap...

  10. 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.

  11. Evaluation the course of the vehicle braking process in case of hydraulic circuit malfunction

    Science.gov (United States)

    Szczypiński-Sala, W.; Lubas, J.

    2016-09-01

    In the paper, the results of the research were discussed, the aim of which was the evaluation of the vehicle braking performance efficiency and the course of this process with regard to the dysfunction which may occur in braking hydraulic circuit. As part of the research, on-road tests were conducted. During the research, the delay of the vehicle when braking was measured with the use of the set of sensors placed in the parallel and the perpendicular axis of the vehicle. All the tests were conducted on the same flat section of asphalt road with wet surface. Conditions of diminished tire-to-road adhesion were chosen in order to force the activity of anti-lock braking system. The research was conducted comparatively for the vehicle with acting anti-lock braking system and subsequently for the vehicle without the system. In both cases, there was a subsequent evaluation of the course of braking with efficient braking system and with the dysfunction of hydraulic circuit.

  12. Parity space-based fault diagnosis of CCBII braking system

    Institute of Scientific and Technical Information of China (English)

    黄志武; 杨迎泽; 王晶; 李赟

    2013-01-01

    Fault diagnosis is a key issue of the CCBII(computer controlled brake II) braking system, because the CCBII braking system is very complicated and nonlinear, which may exhibit isolated and multi-component coupled faults. A parity space-based method was proposed for fault diagnosis of CCBII braking systems. Firstly, the mathematical models were established according to three function modules of CCBII braking systems where the air fluid theory was utilized. Then, parity vector and threshold function were designed for each output of the system so as to identify more system faults. Fault character matrix was built based on the causal relationship between the output and the fault according to the system function and internal structure. Finally, fault detection and isolation can be realized by the comparison of the observed system output and the fault character matrix. Simulation results show that the proposed method is entirely feasible and effective.

  13. Braking system for use with an arbor of a microscope

    Science.gov (United States)

    Norgren, Duane U.

    1984-01-01

    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 device 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. 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.

  15. Designing safe road systems : A Human Factors perspective

    NARCIS (Netherlands)

    Theeuwes, J.; Horst, A.R.A. van der; Kuiken, M.

    2012-01-01

    Many books focus on individual differences and how those relate to traffic safety, such as accident proneness, gender differences, age, alcohol, and the effects of drugs. Others focus on the safety effects regarding the vehicle, such as airbags, anti-lock brakes, navigation systems, intelligent crui

  16. Wear determination in braking systems by radioisotopes

    International Nuclear Information System (INIS)

    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

  17. Charging valve of the full hydraulic braking system

    Directory of Open Access Journals (Sweden)

    Jinshi Chen

    2016-03-01

    Full Text Available It is known that the full hydraulic braking system has excellent braking performance. As the key component of the full hydraulic braking system, the parameters of the accumulator charging valve have a significant effect on the braking performance. In this article, the key parameters of the charging valve are analyzed through the static theoretical and an Advanced Modeling Environment for performing Simulation of engineering systems (AMESim simulation model of the dual-circuit accumulator charging valve is established based on the real structure parameters first. Second, according to the results of the dynamic simulation, the dynamic characteristics of the charging pressure, the flow rate, and the frequency of the charging valve are studied. The key parameters affecting the serial production are proposed and some technical advices for improving the performance of the full hydraulic system are provided. Finally, the theoretical analysis is validated by the simulation results. The comparison between the simulation results and the experimental results indicates that the simulated AMESim model of the charging valve is accurate and credible with the error rate inside 0.5% compared with the experimental result. Hence, the performance of the charging valve meets the request of the full hydraulic braking system exactly.

  18. Maslov-type index and brake orbits in nonlinear Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, we study the Maslov-type index theory for linear Hamiltonian systems with brake orbits boundary value conditions and its applications to the existence of multiple brake orbits of nonlinear Hamiltonian systems.

  19. 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...

  20. Piecewise polynomial chaos expansion with an application to brake squeal of a linear brake system

    Science.gov (United States)

    Sarrouy, E.; Dessombz, O.; Sinou, J.-J.

    2013-02-01

    This paper proposes numerical developments based on polynomial chaos (PC) expansions to process stochastic eigenvalue problems efficiently. These developments are applied to the problem of linear stability calculations for a simplified brake system: the stability of a finite element model of a brake is investigated when its friction coefficient or the contact stiffness are modeled as random parameters. Getting rid of the statistical point of view of the PC method but keeping the principle of a polynomial decomposition of eigenvalues and eigenvectors, the stochastic space is decomposed into several elements to realize a low degree piecewise polynomial approximation of these quantities. An approach relying on continuation principles is compared to the classical dichotomy method to build the partition. Moreover, a criterion for testing accuracy of the decomposition over each cell of the partition without requiring evaluation of exact eigenmodes is proposed and implemented. Several random distributions are tested, including a uniform-like law for description of friction coefficient variation. Results are compared to Monte Carlo simulations so as to determine the method accuracy and efficiency. Some general rules relative to the influence of the friction coefficient or the contact stiffness are also inferred from these calculations.

  1. Subway Train Braking System: A Fuzzy Based Hardware Approach

    Directory of Open Access Journals (Sweden)

    Mamun B.I. Reaz

    2011-01-01

    Full Text Available Problem statement: Automated subway train-braking system require perfection, efficiency and fast response. In order to cope with this concerns, an appropriate algorithm need to be developed which need to be implemented in hardware for faster response. Approach: In this research, the FPGA realization of fuzzy based subway train braking system has been presented on an Alter FLEX10K device to provide an accurate and increased speed of convergence of the network. The fuzzy based subway train braking system is comprised of fusilier, inference, rule selector and defuzzifier modules. Sixteen rules are identified for the rule selector module. After determining the membership functions and its fuzzy variables, the Max-Min Composition method and Madman-Min implication operator are used for the inference module and the Centre of Gravity method is used for the defuzzification module. Each module is modeled individually using behavioral VHDL. The layers are then connected using structural VHDL. Two 8-bit and one 8-bit unsigned digital signals are used for input and output respectively. Six ROMs are defined in order to decrease the chances of processing and increasing the throughput of the system. Results: Functional simulations were commenced to verify the functionality of the individual modules and the system as well. We have validated the hardware implementation of the proposed approach through comparison, verification and analysis. The design has utilized 2372 units of LC with a system frequency of 139.8MHz. Conclusion: In this research, the FPGA realization of fuzzy brake system of subway train has been successfully implemented with minimum usage of logic cells. The validation study with C model shows that the hardware model is appropriate and the hardware approach shows faster and accurate response with full automatic control.

  2. Anti-lock Braking Self-adjustment Logic Gate Limiting Value Control based on MATLAB%基于MATLAB的制动防抱死自调节门限值控制

    Institute of Scientific and Technical Information of China (English)

    陈启帆; 苗水雯; 万能

    2014-01-01

    In order to get good control effects in anti-braking simulation study,the logic gate of logic gate limiting value control will be changed with the change of speed and road adhesion coefficient.The vehicle model with wheeled three de-grees of freedom and effective logic gate limiting value control strategy were created in MATLAB for research on self-adj ust-ment logic gate control.Simulation tests were carried out for multiple speeds of cases and variety of road adhesion coeffi-cient.Did simulation tests under different vehicle speed and different adhesion coefficient,and did observation selecting two important parameters,which were slip rate and wheel speed,through the analysis of duration of best slip rate and stability of wheel rotation,testified the effectiveness of self-adj ustment logic gate limiting control.%为了在制动防抱死仿真研究中取得良好的控制效果,逻辑门限值控制方法中的最佳门限值会随着车速和路面附着系数的情况变化而变化。以研究自调节门限值的控制方式为目的,在 MATLAB软件中创建了双轮三自由度车辆模型以及有效的逻辑门限值控制策略。在不同车速及不同附着系数的路面进行了仿真试验,并且选取车轮滑移率和车轮速2个重要参数进行考察,通过对最佳滑移率持续时间以及车轮的转动稳定性分析,验证了该自调节门限值控制的有效性。

  3. 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.

  4. Carbon nanotube torsional springs for regenerative braking systems

    Science.gov (United States)

    Liu, Sanwei; Martin, Corbin; Lashmore, David; Schauer, Mark; Livermore, Carol

    2015-10-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg-1  ±  1.2 kJ kg-1 and 3.4 kJ kg-1  ±  0.4 kJ kg-1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg-1 and 0.67 kW kg-1, respectively, with maximum measured values of up to 4.7 kJ kg-1 and 1.2 kW kg-1, respectively. A slightly lower energy density of up to 1.2 kJ kg-1 and a 0.29 kW kg-1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism.

  5. Climate Based Performance of Carbon-Carbon Disc Brake for High Speed Aircraft Braking System

    Directory of Open Access Journals (Sweden)

    R. M. Mohanty

    2013-09-01

    Full Text Available Carbon composite brake discs are lighter, economical, and have excellent high energy friction characteristics. These have twice thermal capability compared to steel, remain unaffected by thermal shocks and mechanical fatigue. These are highly useful in emergency breaking situations. Prior to this work, two dimensional (2D reinforced carbon composite laminates were prepared through pitch impregnation process. In an effort to protect the exposed non frictional surface from high temperature service degradations, multilayered ceramic coating systems were developed on 2D composite. Oxidation studies have been carried out on these systems viz., C-SiC, C-SiC-MoSi2-Al2O3 and C-SiC-B4C. These were performed both in dynamic and static conditions up to 1200 °C in 60 per cent humid climate. The hardness, surface topography, developed phases and integrity of layers on the samples at various stages of the experiment have been characterized and analyzed. It was observed that C-SiC-B4C system performs well in the oxidizing environment.Defence Science Journal, 2013, 63(5, pp.531-538, DOI:http://dx.doi.org/10.14429/dsj.63.3932

  6. 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.

  7. 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.

  8. 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

  9. Dynamic Braking System of a Tidal Generator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Wright, Alan; Gevorgian, Vahan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2016-08-01

    Renewable energy generation has experienced significant cost reductions during the past decades, and it has become more accepted by the global population. In the beginning, wind generation dominated the development and deployment of renewable energy; however, during recent decades, photovoltaic (PV) generation has grown at a very significant pace due to the tremendous decrease in the cost of PV modules. The focus on renewable energy generation has now expanded to include new types with promising future applications, such as river and tidal generation. The input water flow to these types of resources is more predictable than wind or solar generation. The data used in this paper is representative of a typical river or tidal generator. The analysis is based on a generator with a power rating of 40 kW. The tidal generator under consideration is driven by two sets of helical turbines connected to each side of the generator located in between the turbines. The generator is operated in variable speed, and it is controlled to maximize the energy harvested as well as the operation of the turbine generator. The electrical system consists of a three-phase permanent magnet generator connected to a three-phase passive rectifier. The output of the rectifier is connected to a DC-DC converter to match the rectifier output to the DC bus voltage of the DC-AC inverter. The three-phase inverter is connected to the grid, and it is controlled to provide a good interface with the grid. One important aspect of river and tidal generation is the braking mechanism. In a tidal generator, the braking mechanism is important to avoid a runaway condition in case the connection to the grid is lost when there is a fault in the lines. A runaway condition may lead to an overspeed condition and cause extreme stresses on the turbine blade structure and eventual disintegration of the mechanical structure. In this paper, the concept of the dynamic braking system is developed and investigated for normal

  10. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Science.gov (United States)

    2010-10-01

    ... Federal Motor Vehicle Safety Standards § 571.135 Standard No. 135; Light vehicle brake systems. S1. Scope... driving conditions. S3. Application. This standard applies to passenger cars manufactured on or after... Vehicle No. 105, Hydraulic Brake Systems. S4. Definitions. Adhesion utilization curves means...

  11. Braking Distance Prediction by Hydroplaning Analysis of 3-D Patterned Tire Model

    Science.gov (United States)

    Cho, Jin-Rae; Choi, Joo-Hyoung; Lee, Hong-Woo; Woo, Jong-Shik; Yoo, Wan-Suk

    In this paper, we present a wet-road braking distance estimate for the vehicles equipped with ABS (Anti-lock Brake System). In order to effectively compute the interval-wise braking times and the resulting total braking distance, we divide the entire speed interval at braking into finite number of uniform sub-intervals and apply the energy conservation law to individual sub-intervals. The proposed method is based on a numerical-analytical approach such that the frictional energy loss of the patterned tire is computed by 3-D hydroplaning analysis while the other at the disc pad is analytically derived. The hydroplaning simulation is performed by generally coupling an Eulerian finite volume method and an explicit Lagrangian finite element method. The operation of ABS is numerically implemented by controlling the tire angular velocity such that the preset tire slip ratio on the wet road is maintained. Numerical results are presented to illustrative and verify the the proposed numerical estimate.

  12. Design of Braking Caliper's Braking Torque in Hydraulic Disc Braking System%液压盘式刹车系统制动钳制动力矩的设计

    Institute of Scientific and Technical Information of China (English)

    高燕; 宋胜涛; 王跃军; 韩美香; 郭太清

    2012-01-01

    针对目前液压盘式刹车系统刹车力矩小,刹车性能不稳定等现状,基于老算法对制动转矩的计算原理设计了一种新算法,对制动钳的工作制动转矩,紧急制动转矩及驻车制动转矩,冗余安全设计等进行了计算.为提高液压盘式刹车系统的设计效率和安全系数,该算法从制动钳的工作原理出发,通过对制动钳的制动结构进行分析,以下放到井中的最重套管柱所形成的静制动转矩作为盘刹系统能满足的最小工作制动转矩为依据,通过验证计算结果,保障了液压盘式刹车系统的安全性和有效性.%The current braking torque of the hydraulic disc braking system is small and braking performance is instable.A new algorithm was designed based on the braking torque's calculation of the old algorithm.The work braking torque, emergency braking torque, park braking torque and the redundant safety design were calculated in this new algorithm.To improve the design efficiency and safety coefficient of the hydraulic disc braking system, the algorithm based on the working principle of the braking caliper, through the braking structure analysis of the braking caliper, according to the static braking torque formed by the heaviest casing string that put into the well could be taken as the minimum working braking torque which the disc braking system could meet.The safety and effectiveness of the hydraulic disc braking system are safeguarded through the authentication and calculation of the result.

  13. Analysis of heat conduction in a drum brake system of the wheeled armored personnel carriers

    Science.gov (United States)

    Puncioiu, A. M.; Truta, M.; Vedinas, I.; Marinescu, M.; Vinturis, V.

    2015-11-01

    This paper is an integrated study performed over the Braking System of the Wheeled Armored Personnel Carriers. It mainly aims to analyze the heat transfer process which is present in almost any industrial and natural process. The vehicle drum brake systems can generate extremely high temperatures under high but short duration braking loads or under relatively light but continuous braking. For the proper conduct of the special vehicles mission in rough terrain, we are talking about, on one hand, the importance of the possibility of immobilization and retaining position and, on the other hand, during the braking process, the importance movement stability and reversibility or reversibility, to an encounter with an obstacle. Heat transfer processes influence the performance of the braking system. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of analyzed vehicle wheels. In the present work a finite element model for the temperature distribution in a brake drum is developed, by employing commercial finite element software, ANSYS. These structural and thermal FEA models will simulate entire braking event. The heat generated during braking causes distortion which modifies thermoelastic contact pressure distribution drum-shoe interface. In order to capture the effect of heat, a transient thermal analysis is performed in order to predict the temperature distribution transitional brake components. Drum brakes are checked both mechanical and thermal. These tests aim to establish their sustainability in terms of wear and the variation coefficient of friction between the friction surfaces with increasing temperature. Modeling using simulation programs led eventually to the establishment of actual thermal load of the mechanism of brake components. It was drawn the efficiency characteristic by plotting the coefficient of effectiveness relative to the coefficient of friction shoe-drum. Thus induced

  14. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Science.gov (United States)

    2012-08-24

    ... passenger cars.\\7\\ \\6\\ Response to Petitions for Reconsideration, Motorcycle Brake Systems, 37 FR 11973... braking performance, they have not kept pace with the advancement of modern technologies. The National... reflects the capabilities of current in-use technologies. Updating the standard to reflect...

  15. 49 CFR 571.122 - Standard No. 122; Motorcycle brake systems.

    Science.gov (United States)

    2010-10-01

    ... conditions. S3. Application. This standard applies to motorcycles. S4. Definitions. Braking interval means... Federal Motor Vehicle Safety Standards § 571.122 Standard No. 122; Motorcycle brake systems. S1. Scope... the sequence specified in S7. Corresponding test procedures of S7 are indicated in parentheses. If...

  16. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2011-07-27

    ... 6x4 tractor with a 190-inch wheelbase, equipped with a hybrid disc brake configuration. The vehicle... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AK84 Federal Motor Vehicle Safety... published a final rule that amended the Federal motor vehicle safety standard for air brake systems...

  17. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Science.gov (United States)

    2010-10-01

    ... or locomotive equipped with an ECP brake system that is found with inoperative or ineffective brakes...; provided, all applicable provisions of this section are met and the defective car or locomotive is hauled... appliance may be used or hauled without civil penalty under this part to the nearest or nearest...

  18. 49 CFR 570.5 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ...) Friction materials. On each brake the thickness of the lining or pad shall not be less than one thirty... CFR 571.105, on every new passenger car manufactured on or after January 1, 1968, and on other types... from loose material, oil, or grease. The service brakes shall be applied at a vehicle speed of 20...

  19. 49 CFR 570.59 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ...) Friction materials. On each brake, the thickness of the lining or pad shall not be less than one thirty-second of an inch over the fastener, or one-sixteenth of an inch over the brake shoe on bonded linings or... percent grade), dry, smooth, hard-surfaced road that is free from loose material, oil or grease....

  20. 基于HHT去噪和互相关原理的ABS制动液压力波波速的研究%Research of Pressure Wave Velocity of Brake Fluid of ABS Based on HHT and Principle of Cross-correlation

    Institute of Scientific and Technical Information of China (English)

    戚雪珍; 李孝禄; 王文越

    2016-01-01

    汽车防抱死系统( ABS)依靠制动液压力波传递制动压力,对汽车制动效能影响很大。文中利用压力传感器采集ABS制动液压力,对采集的数据进行希尔伯特-黄变换( HHT)去噪,再利用互相关原理对不同刹车盘转速和制动管路长度下的制动液压力波波速进行计算。研究表明,制动液压力波波速可达1181.8 m/s。%Pressure wave velocity of brake fluid of Anti-lock braking system( ABS) have an obvious effect on brake ability of automobile, which transfers braking pressure for braking disc. The brake fluid pressure was acquired by the pressure transmitters in an ABS, and with Hilbert-huang transform ( HHT) de-noised. The pressure wave velocities of brake fluid were calculated by the cross-correlation principle under different rotating speeds and braking pipe lengths. The results show that the pressure wave velocity of brake fluid is up to 1 181.8m/s.

  1. Research and Development of ECU in Hydraulic Anti-lock Braking System%液压ABS电控单元的研究开发

    Institute of Scientific and Technical Information of China (English)

    张新; 吴志强; 姜陵

    2003-01-01

    介绍了自行开发的液压ABS,采用新的手段建立开发系统,使得ABS从概念到产品的开发周期缩短,并保证产品性能的可靠性.通过实车道路试验对比,自行开发的ABS产品性能已达到德国Bosch5.3产品的水平.

  2. Test Study on Vehicle Anti-lock Brake System%汽车防抱死制动系统试验研究

    Institute of Scientific and Technical Information of China (English)

    靳旗; 林毅

    2006-01-01

    首先对ABS的作用做了较详细的介绍,然后重点对ABS试验方法和评价方法做了较详细的论述.本文对ABS的性能评价是以装车后进行实车道路试验的方式进行的,在评价方法方面,文章提出了利用多个参数来对ABS系统进行综合评价,该理论不仅适用于ABS产品的认证,更适用于ABS产品的研究及开发.

  3. 汽车ABS控制技术与发展%Control technology and development of automotive anti-lock braking system (ABS)

    Institute of Scientific and Technical Information of China (English)

    林志伟; 严世榕

    2008-01-01

    介绍了汽车防抱死制动系统ABS的历史与发展,以及ABS的构成和单轮制动原理,论述了国内外常见的ABS控制策略,并分析了ABS整车稳定性控制,最后结合汽车电子技术的发展,探讨了车载ABS的扩展功能.

  4. Study on control algorithm of Anti-lock Braking System%车辆防抱死制动系统(ABS)控制算法的研究

    Institute of Scientific and Technical Information of China (English)

    马明星; 毛务本; 朱伟兴

    2002-01-01

    本文从车辆动力学分析着手,阐述了ABS的控制机理,并提出了基于路面附着系数的ABs全新控制算法.在自行设计的转鼓试验台架上进行了试验,证实了此控制算法的有效性,为加速ABS产品化提供了有效的手段.

  5. Advanced Emergency Braking Controller Design for Pedestrian Protection Oriented Automotive Collision Avoidance System

    OpenAIRE

    Guo Lie; Ren Zejian; Ge Pingshu; Chang Jing

    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...

  6. Brake Pedal Displacement Measuring System based on Machine Vision

    Directory of Open Access Journals (Sweden)

    Chang Wang

    2013-10-01

    Full Text Available Displacement of brake pedal was an important characteristic of driving behavior. This paper proposed a displacement measure algorithm based on machine vision. Image of brake pedal was captured by camera from left side, and images were processed in industry computer. Firstly, average smooth algorithm and wavelet transform algorithm were used to smooth the original image consecutively. Then, edge extracting method which combined Roberts’s operator with wavelet analysis was used to identify the edge of brake pedal. At last, least square method was adopted to recognize the characteristic line of brake pedal’s displacement. The experimental results demonstrated that the proposed method takes the advantages of Roberts’s operator and wavelet transform, it can obtain better measurement result as well as linear displacement sensors

  7. Stability analysis and μ-synthesis control of brake systems

    OpenAIRE

    Lignon, Sylvain; Sinou, Jean-Jacques; Jezequel, Louis

    2006-01-01

    The concept of friction-induced brake vibrations, commonly known as judder, is investigated. Judder vibration is based on the class of geometrically induced or kinematic constraint instability. After presenting the modal coupling mechanism and the associated dynamic model, a stability analysis as well as a sensitivity analysis have been conducted in order to identify physical parameters for a brake design avoiding friction-induced judder instability. Next, in order to reduce the size of the i...

  8. Stability analysis and \\mu-synthesis control of brake systems

    OpenAIRE

    Lignon, Sylvain; Sinou, Jean-Jacques; Jezequel, Louis

    2008-01-01

    The concept of friction-induced brake vibrations, commonly known as judder, is investigated. Judder vibration is based on the class of geometrically induced or kinematic constraint instability. After presenting the modal coupling mechanism and the associated dynamic model, a stability analysis as well as a sensitivity analysis have been conducted in order to identify physical parameters for a brake design avoiding friction-induced judder instability. Next, in order to reduce the size of the i...

  9. STUDY ON THE CONTROL SYSTEM OF HYDRAULIC MOMENT-ADJUSTED BRAKE FOR DOWNWARD BELT CONVEYOR

    Institute of Scientific and Technical Information of China (English)

    孟国营; 徐志强; 霍森; 方佳雨

    1997-01-01

    Having analyzed the drawbacks on the design of control system of hydraulic momentadjusted brake system, the author presents a closed loop control system in the process of start and braking of the conveyer. On the basis of the concept of the critical time and the critical acceleration and its deductions, the working mode of the conveyer can be identified and controlled in feedback, furthermore, thus realize the process of soft start. In the deceleration process, the author points out the problems that exist in the present control system and sets forward the control process that acted by the combined function of brake moment of motor and the drag torque of hydraulic brake at the beginning of deceleration, it will further improved reliability of conveyor system.

  10. Design and Development of Hydraulic Disc Brake Systems for Well Servicing Rig Drawworks

    Institute of Scientific and Technical Information of China (English)

    Gao xiangqian; Zhou Yongxia

    1996-01-01

    @@ The conventional band brakes have been known to be important but also the most unlnerable part in servicing rig deawworks.. The failures in braking and releasing operations haven't well been avoided. There have evidently existed the problems of difficult operation and inconvenient maintenance in this connection. The use of power-assisted hydraulic cylinders or pneumatic cylinders can not meet the requirements of operations either. Since the late 1980s, we have cooperated with Shengli oilfields and others in the successful design and development of PST25 hydraulic disc brake systems for well servicing rig in a fully closed working state.

  11. Analysis of electrodynamic brake for utilization in systems with rotating shafts

    OpenAIRE

    Sokolov, Georgii

    2016-01-01

    The goal of this study was to conduct an analysis of an opportunity to apply eddy current brakes in dynamical systems containing rotating shafts. While conducting the research the general principles of deceleration, eddy currents’ origin, basics of magnetism and currently existing types of brakes were clarified and gathered briefly, but informatively. The theory which is explained in this thesis was taken from reliable secondary sources. The concepts of physics were investigated from sever...

  12. On a Flywheel-Based Regenerative Braking System for Regenerative Energy Recovery

    OpenAIRE

    Hsu, Tai-Ran

    2013-01-01

    This paper presents a unique flywheel-based regenerative energy recovery, storage and release system developed at the author's laboratory. It can recover and store regenerative energy produced by braking a motion generator with intermittent rotary velocity such as the rotor of a wind turbogenerator subject to intermittent intake wind and the axels of electric and hybrid gas-electric vehicles during frequent coasting and braking. Releasing of the stored regenerative energy in the flywheel is c...

  13. Smart brake light system would provide more information to drivers

    OpenAIRE

    Trulove, Susan

    2008-01-01

    You are driving in heavy traffic. The brake lights on the car in front of you come on. Is the car slowing or is it going to stop? It slows to 25 mph and the lights go off. You drop back. The car in front of you stops suddenly! You stop just in time. The car behind you collects your rear bumper.

  14. Regenerative braking systems with torsional springs made of carbon nanotube yarn

    Science.gov (United States)

    Liu, S.; Martin, C.; Lashmore, D.; Schauer, M.; Livermore, C.

    2014-11-01

    The demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as an energy-storing actuator for regenerative braking systems. Originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing until failure. The maximum extractable energy density is measured to be as high as 6.13 kJ/kg. The tests also reveal structural reorganization and hysteresis in the torsional loading curves. A regenerative braking system is built to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yam's twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking system are up to 4.69 kJ/kg and 1.21 kW/kg, respectively. A slightly lower energy density of up to 1.23 kJ/kg and a 0.29 kW/kg mean power density are measured for the CNT yarns in a more complex system that mimics a unidirectional rotating regenerative braking mechanism. The lower energy densities for CNT yarns in the regenerative braking systems as compared with the yarns themselves reflect the frictional losses of the regenerative systems.

  15. Research on Electro Hydraulic Proportional Control for Heavy Vehicle Blend Braking System

    Institute of Scientific and Technical Information of China (English)

    XU Ming

    2009-01-01

    A blend braking system of heavy vehicle was proposed. The main control part of the system is the electro hydraulic proportional servo valve. A nonlinear model of brake cylinder controlled by the valve was deduced through the analysis of its control property and system feature. The transfer function of the system was also proposed, and the hydraulic inherent frequency and the PID closed-loop system feature were calculated. The simulated result is consistent with those tested in the bench and on the site with 50t heavy vehicle. The experimental result shows that the control method has quick response and high precision.

  16. Laboratory testing of airborne brake wear particle emissions using a dynamometer system under urban city driving cycles

    Science.gov (United States)

    Hagino, Hiroyuki; Oyama, Motoaki; Sasaki, Sousuke

    2016-04-01

    To measure driving-distance-based mass emission factors for airborne brake wear particulate matter (PM; i.e., brake wear particles) related to the non-asbestos organic friction of brake assembly materials (pads and lining), and to characterize the components of brake wear particles, a brake wear dynamometer with a constant-volume sampling system was developed. Only a limited number of studies have investigated brake emissions under urban city driving cycles that correspond to the tailpipe emission test (i.e., JC08 or JE05 mode of Japanese tailpipe emission test cycles). The tests were performed using two passenger cars and one middle-class truck. The observed airborne brake wear particle emissions ranged from 0.04 to 1.4 mg/km/vehicle for PM10 (particles up to 10 μm (in size), and from 0.04 to 1.2 mg/km/vehicle for PM2.5. The proportion of brake wear debris emitted as airborne brake wear particles was 2-21% of the mass of wear. Oxygenated carbonaceous components were included in the airborne PM but not in the original friction material, which indicates that changes in carbon composition occurred during the abrasion process. Furthermore, this study identified the key tracers of brake wear particles (e.g., Fe, Cu, Ba, and Sb) at emission levels comparable to traffic-related atmospheric environments.

  17. 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

  18. Advanced Emergency Braking Controller Design for Pedestrian Protection Oriented Automotive Collision Avoidance System

    Directory of Open Access Journals (Sweden)

    Guo Lie

    2014-01-01

    Full Text Available 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 current distance between the host vehicle and the obstacle with the critical braking distance. To reflect the nonlinear time-varying characteristics and control effect of the longitudinal dynamics, the vehicle longitudinal dynamics model is established in CarSim. Then the braking controller with the structure of upper and lower layers is designed based on sliding mode control and the single neuron PID control when confronting deceleration or emergency braking conditions. Cosimulations utilizing CarSim and Simulink are finally carried out on a CarSim intelligent vehicle model to explore the effectiveness of the proposed controller. Results display that the designed controller has a good response in preventing colliding with the front vehicle or pedestrian.

  19. Comparative analysis into the tractor-trailer braking dynamics: tractor with single axle brakes, tractor with all wheel brakes

    Science.gov (United States)

    Nastasoiu, Mircea; Ispas, Nicolae

    2014-06-01

    The paper elaborates a mathematical model in order to conduct a study into the dynamics of tractor-trailer systems during braking. The braking dynamics is analyzed by considering two versions for the braking system: 1) braking applied on the rear axle and 2) braking applied on all four wheels. In both versions the trailer is braked on all wheels. The mathematical model enables us to determine and graphically illustrate the evolution of the following parameters: braking deceleration, braking speed and the distance traveled by the tractor during braking. The mathematical model elaborated is applied on a tractor-trailer system completing transportation works.

  20. 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.

  1. Optimal design method for force in vibration control of multi-body system with quick startup and brake

    Institute of Scientific and Technical Information of China (English)

    TANG Hua-ping; PENG Ya-qing

    2005-01-01

    A kind of active vibration control method was presented through optimal design of driving load of multi-body system with quick startup and brake. Dynamical equation of multi-body system with quick startup and brake was built, and mathematical model of representing vibration control was also set up according to the moving process from startup to brake. Then optimization vibration control model of system driving load was founded by applying theory of optimization control, which takes rigid body moving variable of braking moment as the known condition, and vibration control equation of multi-body system with quick startup and brake was converted into boundary value problem of differential equation. The transient control algorithm of vibration was put forward, which is the analysis basis for the further research. Theoretical analysis and calculation of numerical examples show that the optimal design method for the multi-body system driving load can decrease the vibration of system with duplication.

  2. 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.

  3. 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.

  4. 49 CFR 571.121 - Standard No. 121; Air brake systems.

    Science.gov (United States)

    2010-10-01

    ... Motor Vehicle Safety Standards § 571.121 Standard No. 121; Air brake systems. S1. Scope. This standard... emergency conditions. S3. Application. This standard applies to trucks, buses, and trailers equipped with... definition of heavy hauler trailer set forth in S4; (f) Any trailer that has an unloaded vehicle weight...

  5. Study on Cooperative Control Method of Vehicle Steering/Anti-lock Braking System%汽车转向/防抱死制动系统的协调控制研究

    Institute of Scientific and Technical Information of China (English)

    李果; 刘华伟; 王旭

    2012-01-01

    A new cooperative control system was proposed for the vehicle's steering antilock braking stability fields.The cooperative control architecture is composed with the execution layer and the cooperation layer.On the execution layer,based on the optimum slip ratio,the vehicle adjustable sliding mode controller was designed for the robustness of vehicles.Moreover,the adaptor was designed to adjust the gain of sliding mode control parameters,so as to reduce the chatter.On the other hand,the yaw moment and the front wheel angle controllers based on the robust adaptive control law were designed to improve the respond,adaptive robustness and stability of vehicles.On the cooperation layer,the brake force distribution policy applicable to the complex work condition and a new cooperative control method were proposed to solve the problems of steering and braking systems.Finally,the stability and the validity of the control algorithm were validated by simulation results.%协同控制结构由执行级和协调级组成。在执行级中,设计基于最佳滑移率的汽车防抱死制动可调节滑模控制器。针对滑模控制中固有抖振缺陷,自动适时调节控制参数增益以消弱抖振。此外,设计基于鲁棒自适应控制的横摆力矩控制器和主动前轮转向控制器力求改善汽车动态响应、鲁棒自适应性和稳定性。在协调级中,设计适用于复杂工况的制动力分配策略,并提出一种协调控制转向系统和制动系统的新方法。最后用仿真结果验证所设计控制算法的稳定性和有效性。

  6. Mechanical braking system for the pulsed power supply system of ASDEX Upgrade

    International Nuclear Information System (INIS)

    Highlights: ► Compact and innovative solution for dumping of large kinetic energy. ► Small mass of energy converter at the shaft due to circulating storage medium. ► Design of the active parts ensures flat torque/power characteristics. ► Also suitable for spending a great part of operating life in “Freewheeling” mode. -- Abstract: A few years ago, IPP reviewed the safety of the ASDEX Upgrade pulsed power supply system. Two critical sub-systems had been identified: The (electrical) braking system for the flywheel generators and the oil lubrication system for the shaft bearings. A simultaneous failure of these two systems may lead to severe damages and could have consequences for the safety of operating personnel. Therefore a second, independent braking possibility for every generator was stipulated. Especially the challenges adapting a dynamometer, originally designed for motor test benches, towards a plant safety system for generator EZ4 will be described in the paper. Further on, the paper will present the problems, implementing such a system into an existing installation, including the calculation of the required supporting structure, balancing of the extended shaft line and required water cooling and control. Finally it will report on the performance achieved during operation

  7. Mechanical braking system for the pulsed power supply system of ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Käsemann, C.-P., E-mail: c.p.kaesemann@ipp.mpg.de [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Huart, M. [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Michel Huart Personal Coaching and Consulting, Georgenschwaigstraße 23 RG, 80807 München (Germany); Stobbe, F.; Goldstein, I.; Sigalov, A. [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Sachs, E. [Siemens AG, Industrial Automation Systems, Gleiwitzer Straße 555, 90475 Nürnberg (Germany); Perk, E. [Piper Test and Measurement Ltd., The Barn, Bilsington, Ashford, Kent TN25 7JT, England (United Kingdom)

    2013-10-15

    Highlights: ► Compact and innovative solution for dumping of large kinetic energy. ► Small mass of energy converter at the shaft due to circulating storage medium. ► Design of the active parts ensures flat torque/power characteristics. ► Also suitable for spending a great part of operating life in “Freewheeling” mode. -- Abstract: A few years ago, IPP reviewed the safety of the ASDEX Upgrade pulsed power supply system. Two critical sub-systems had been identified: The (electrical) braking system for the flywheel generators and the oil lubrication system for the shaft bearings. A simultaneous failure of these two systems may lead to severe damages and could have consequences for the safety of operating personnel. Therefore a second, independent braking possibility for every generator was stipulated. Especially the challenges adapting a dynamometer, originally designed for motor test benches, towards a plant safety system for generator EZ4 will be described in the paper. Further on, the paper will present the problems, implementing such a system into an existing installation, including the calculation of the required supporting structure, balancing of the extended shaft line and required water cooling and control. Finally it will report on the performance achieved during operation.

  8. Simulation and Experimental Analysis of Braking Squeal of Disc Brake System Considering Thermo-mechanical Coupling Effect%盘式制动器制动尖叫热机耦合特性仿真分析

    Institute of Scientific and Technical Information of China (English)

    汪德成; 陈凌珊; 黄欣; 蒋培露

    2014-01-01

    利用试验和仿真相结合的方法,对某车型前通风盘式制动器进行研究。基于多功能制动器动力学试验台架,分别对两套同型号制动器试件进行制动尖叫试验,基于有限元建立制动器热机耦合分析模型,在拖滞制动模式下进行仿真计算。分析研究表明,拖滞制动模式是一个明显的热机耦合过程,其热机耦合效应与减速制动模式具有很多共同点。热机耦合效应对制动尖叫影响较大,考虑热机耦合效应有利于提高尖叫预测精度,并能够反映制动尖叫的时变特性。%Braking squeal of ventilation disc brake systems was studied through experimental and numerical analysis. Using multi-function brake dynamometer test rig, brake squeal tests of two disc brake systems were carried out. The finite element model of the disc brake was built, and the thermo-mechanical coupling effect was investigated under drag braking conditions. The simulation results show that the thermo-mechanical coupling effect exists obviously in drag braking mode, which is similar to that in emergency braking mode. This effect has a serious influence on braking squeal. It must be considered in the brake squeal simulation analysis to improve the prediction accuracy and to reflect the time-varying characteristics of the braking squeal.

  9. Autonomous collision avoidance system by combined control of steering and braking using geometrically optimised vehicular trajectory

    Science.gov (United States)

    Hayashi, Ryuzo; Isogai, Juzo; Raksincharoensak, Pongsathorn; Nagai, Masao

    2012-01-01

    This study proposes an autonomous obstacle avoidance system not only by braking but also by steering, as one of the active safety technologies to prevent traffic accidents. The proposed system prevents the vehicle from colliding with a moving obstacle like a pedestrian jumping out from the roadside. In the proposed system, to avoid the predicted colliding position based on constant-velocity obstacle motion assumption, the avoidance trajectory is derived as connected two identical arcs. The system then controls the vehicle autonomously by the combined control of the braking and steering systems. In this paper, the proposed system is examined by real car experiments and its effectiveness is shown from the results of the experiments.

  10. Sustainable urban rail systems: Strategies and technologies for optimal management of regenerative braking energy

    International Nuclear Information System (INIS)

    Highlights: • Review of principal regenerative braking strategies and technologies for urban rail. • Different energy storage technologies are assessed for use in urban rail. • Optimising timetables is a preferential measure to improve energy efficiency. • Energy storage systems improve efficiency and reliability of urban rail systems. • Reversible substations allow for a complete recovery of braking energy. - Abstract: In a society characterised by increasing rates of urbanisation and growing concerns about environmental issues like climate change, urban rail transport plays a key role in contributing to sustainable development. However, in order to retain its inherent advantages in terms of energy consumption per transport capacity and to address the rising costs of energy, important energy efficiency measures have to be implemented. Given that numerous and frequent stops are a significant characteristic of urban rail, recuperation of braking energy offers a great potential to reduce energy consumption in urban rail systems. This paper presents a comprehensive overview of the currently available strategies and technologies for recovery and management of braking energy in urban rail, covering timetable optimisation, on-board and wayside Energy Storage Systems (ESSs) and reversible substations. For each measure, an assessment of their main advantages and disadvantages is provided alongside a list of the most relevant scientific studies and demonstration projects. This study concludes that optimising timetables is a preferential measure to increase the benefits of regenerative braking in any urban rail system. Likewise, it has been observed that ESSs are a viable solution to reuse regenerative energy with voltage stabilisation and energy saving purposes. Electrochemical Double Layer Capacitors has been identified as the most suitable technology for ESSs in general, although high specific power batteries such as Li-ion may become a practical option for on

  11. Active vibration control of multibody system with quick startup and brake based on active damping

    Institute of Scientific and Technical Information of China (English)

    TANG Hua-ping; TANG Yun-jun; TAO Gong-an

    2006-01-01

    A kind of active vibration control method was presented based on active damping and optimization design for driving load of multibody system with quick startup and brake. Dynamical equation of multibody system with quick startup and brake and piezoelectric actuators intelligent structure was built. The optimum driving load was calculated by applying the presented method. The self-sensing and self-tuning closed-loop active vibration control in quick startup and brake process was realized. The control algorithm, using local velocity negative feedback, i.e. the output of a sensor only affects the output of the actuator collocated, can induce damping effectively to actively suppress the system vibration. Based on the optimization design for driving load of multibody system with quick startup and bake, the active damping of piezoelectric actuators intelligent structure was used to farther suppress the vibration of system. Theoretical analysis and calculation of numerical show that the proposed method makes the vibration of system decrease more than the optimal design method for driving load of multibody system.

  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. 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.

  14. Development of Quasi-3DOF upper limb rehabilitation system using ER brake: PLEMO-P1

    International Nuclear Information System (INIS)

    In recent years, many researchers have studied the potential of using robotics technology to assist and quantify the motor functions for neuron-rehabilitation. Some kinds of haptic devices have been developed and evaluated its efficiency with clinical tests, for example, upper limb training for patients with spasticity after stroke. However, almost all the devices are active-type (motor-driven) haptic devices and they basically require high-cost safety system compared to passive-type (brake-based) devices. In this study, we developed a new practical haptic device 'PLEMO-P1'; this system adopted ER brakes as its force generators. In this paper, the mechanism of PLEMO-P1 and its software for a reaching rehabilitation are described.

  15. Development of Quasi-3DOF upper limb rehabilitation system using ER brake: PLEMO-P1

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, T; Fukushima, K; Furusho, J; Ozawa, T [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: kikuchi@mech.eng.osaka-u.ac.jp

    2009-02-01

    In recent years, many researchers have studied the potential of using robotics technology to assist and quantify the motor functions for neuron-rehabilitation. Some kinds of haptic devices have been developed and evaluated its efficiency with clinical tests, for example, upper limb training for patients with spasticity after stroke. However, almost all the devices are active-type (motor-driven) haptic devices and they basically require high-cost safety system compared to passive-type (brake-based) devices. In this study, we developed a new practical haptic device 'PLEMO-P1'; this system adopted ER brakes as its force generators. In this paper, the mechanism of PLEMO-P1 and its software for a reaching rehabilitation are described.

  16. Modeling and Simulation of integrated steering and braking control for vehicle active safety system

    Directory of Open Access Journals (Sweden)

    Beibei Zhang

    2011-03-01

    Full Text Available Active chassis systems like braking, steering, suspension and propulsion systems are increasingly entering the market. In addition to their basic functions, these systems may be used for functions of integrated vehicle dynamics control. An experimental platform which aims to study the integration control of steering and braking is designed due to the research requirement of vehicle active safety control strategy in this paper. A test vehicle which is equipped with the systems of steer-by-wire and brake-bywire is provided and the Autobox, combined with Matlab/simulink and MSCCarsim, is used to fulfill the RCP (Rapid Control Prototyping and HIL (Hardware-in-loop. The seven-freedom vehicle model is constructed first and the approach of vehicle parameters estimation based on the Extended Kalman Filter (EKF is proposed. Testing the vehicle state through the sensor has its own disadvantage that the cost is high and easily affected by environment outside. To find a actual method of receiving the vehicle state using the ready-made sensors in vehicle, the researchers put forward various estimation method, of which have advantages and disadvantages. Based on the above, this paper applies the EKF to estimate the vehicle state, making the actual estimation come true. The primary control methods and controller designment is carried out to prove the validation of the platform.

  17. 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.

  18. 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.

  19. Probability of failure of the waste hoist brake system at the Waste Isolation Pilot Plant (WIPP)

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, M.A. [Univ. of California, Los Angeles, CA (United States); Sargent, T.J. [Univ. of Chicago, IL (United States)]|[Stanford Univ., CA (United States). Hoover Institution

    1998-01-01

    In its most recent report on the annual probability of failure of the waste hoist brake system at the Waste Isolation Pilot Plant (WIPP), the annual failure rate is calculated to be 1.3E({minus}7)(1/yr), rounded off from 1.32E({minus}7). A calculation by the Environmental Evaluation Group (EEG) produces a result that is about 4% higher, namely 1.37E({minus}7)(1/yr). The difference is due to a minor error in the US Department of Energy (DOE) calculations in the Westinghouse 1996 report. WIPP`s hoist safety relies on a braking system consisting of a number of components including two crucial valves. The failure rate of the system needs to be recalculated periodically to accommodate new information on component failure, changes in maintenance and inspection schedules, occasional incidents such as a hoist traveling out-of-control, either up or down, and changes in the design of the brake system. This report examines DOE`s last two reports on the redesigned waste hoist system. In its calculations, the DOE has accepted one EEG recommendation and is using more current information about the component failures rates, the Nonelectronic Parts Reliability Data (NPRD). However, the DOE calculations fail to include the data uncertainties which are described in detail in the NPRD reports. The US Nuclear Regulatory Commission recommended that a system evaluation include mean estimates of component failure rates and take into account the potential uncertainties that exist so that an estimate can be made on the confidence level to be ascribed to the quantitative results. EEG has made this suggestion previously and the DOE has indicated why it does not accept the NRC recommendation. Hence, this EEG report illustrates the importance of including data uncertainty using a simple statistical example.

  20. Energy and wear optimisation of train longitudinal dynamics and of traction and braking systems

    Science.gov (United States)

    Conti, R.; Galardi, E.; Meli, E.; Nocciolini, D.; Pugi, L.; Rindi, A.

    2015-05-01

    Traction and braking systems deeply affect longitudinal train dynamics, especially when an extensive blending phase among different pneumatic, electric and magnetic devices is required. The energy and wear optimisation of longitudinal vehicle dynamics has a crucial economic impact and involves several engineering problems such as wear of braking friction components, energy efficiency, thermal load on components, level of safety under degraded or adhesion conditions (often constrained by the current regulation in force on signalling or other safety-related subsystem). In fact, the application of energy storage systems can lead to an efficiency improvement of at least 10% while, as regards the wear reduction, the improvement due to distributed traction systems and to optimised traction devices can be quantified in about 50%. In this work, an innovative integrated procedure is proposed by the authors to optimise longitudinal train dynamics and traction and braking manoeuvres in terms of both energy and wear. The new approach has been applied to existing test cases and validated with experimental data provided by Breda and, for some components and their homologation process, the results of experimental activities derive from cooperation performed with relevant industrial partners such as Trenitalia and Italcertifer. In particular, simulation results are referred to the simulation tests performed on a high-speed train (Ansaldo Breda Emu V250) and on a tram (Ansaldo Breda Sirio Tram). The proposed approach is based on a modular simulation platform in which the sub-models corresponding to different subsystems can be easily customised, depending on the considered application, on the availability of technical data and on the homologation process of different components.

  1. 基于 Amesim 的整车制动系统建模与仿真%Braking System Model and Simulation Based on Amesim

    Institute of Scientific and Technical Information of China (English)

    王权; 周飞虎; 岳海姣

    2014-01-01

    In this paper , the structure program of the vehicle braking system is designed and its structure and working principle are also described .Based on the Amesim , the vehicle braking system model is established from the pedal , control system , the wheels and to the body .The model is used to simulate the braking process of three braking conditions such as the slight braking , conventional braking and emergency braking when the displacement of the vehicle braking pedal is at 30 mm, 40 mm and 50 mm respectively .The result shows that the result of simulation is consistent with the theoretical calculation and that the braking system model can accurately simulate the vehicle braking process , provide the theoretical basis for the developing the vehicle braking system , and shorten the development period of the braking system .%设计整车制动系统的结构方案,阐述其结构和工作原理。基于Amesim建立整车制动系统模型,通过该模型仿真汽车在制动踏板位移分别为30,40,50 mm时,分别进行轻微制动、常规制动与紧急制动等3种制动工况的制动过程,结果表明:仿真结果与理论计算一致,该制动系统模型可以准确的模拟汽车的制动过程,给汽车制动系统的研发提供理论依据,可缩短制动系统的研发周期。

  2. 49 CFR 393.49 - Control valves for brakes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Control valves for brakes. 393.49 Section 393.49... NECESSARY FOR SAFE OPERATION Brakes § 393.49 Control valves for brakes. (a) General rule. Except as provided..., which is equipped with power brakes, must have the braking system so arranged that one application...

  3. 计算机数据采集系统在提升机闸瓦制动工况分析中的应用%Application of Computer Data Acquisition System in Hoist Brake Shoe Braking Condition Analysis

    Institute of Scientific and Technical Information of China (English)

    潘武敏

    2013-01-01

    随着计算机数据处理技术的发展,数据采集系统应用到各大生产企业中。文章以矿井提升机制动问题为研究基础,提出了提升机闸瓦制动工况采集系统,通过对该系统的温度、压力以及速度传感器的选择及通信问题设计,实现了提升机闸瓦制动工况的实时数据采集,为今后的提升机制动问题分析提供了可靠的理论依据。%Along with the computer data processing technology development, data acquisition system is applied to the major work of enterprise.This article of mine hoist braking problems as the research foundation, developed to hoist brake shoe braking system.The system of temperature, pressure and speed sensor selection and communication design, realization of hoist brake shoe braking mode of the real-time data collection, for the future of the hoist braking problem analysis provides a reliable theoretical basis.

  4. A METHOD OF CONSTRUCTING A MATRIX OF STATES OF THE DIAGNOSTIC PARAMETERS OF BRAKE SYSTEM OF A CAR

    Directory of Open Access Journals (Sweden)

    Uspensky I. A.

    2014-05-01

    Full Text Available The article describes the method of determining the list of rational diagnostic parameters of the brake system of a vehicle using the theory of probability and mathematical statistics. The problems determining the statistical probabilities of failures on objects considered a run; mathematical models (regression dependence the probability of failure of run; A statistical evaluation of the significance of the coefficients of regression models; verification has been made on the adequacy of the regression models; the probabilities of possible states of objects. On the basis of the construction and analysis of structural- effect model brake system information and calculates the importance of each monitored parameter using the notion of information entropy, determine the parameters to be diagnostic, and builds a matrix condition of brake systems for non-destructive testing, in order to move on maintenance and repair of the actual state

  5. Fundamentals of automotive and engine technology standard drives, hybrid drives, brakes, safety systems

    CERN Document Server

    2014-01-01

    Hybrid drives and the operation of hybrid vehicles are characteristic of contemporary automotive technology. Together with the electronic driver assistant systems, hybrid technology is of the greatest importance and both cannot be ignored by today’s car drivers. This technical reference book provides the reader with a firsthand comprehensive description of significant components of automotive technology. All texts are complemented by numerous detailed illustrations. Contents History of the automobile.- History of the Diesel engine.- Areas of use for Diesel engines.- Basic principles of the Diesel engine.- Basic principles of Diesel fuel-injection.- Basic principles of the gasoline engine.- Inductive ignition system.- Transmissions for motor vehicles.- Motor vehicle safety.- Basic principles of vehicle dynamics.- Car braking systems.- Vehicle electrical systems.- Overview of electrical and electronic systems in the vehicle.- Control of gasoline engines.- Control of Diesel engines.- Lighting technology.- Elec...

  6. 车辆制动储能系统设计%Design of Vehicle Braking Energy Storage System

    Institute of Scientific and Technical Information of China (English)

    张玉宝; 金猛

    2013-01-01

    简述液压混合动力技术的产生背景、应用范围,提出基于汽车的制动性能设计混合动力液压系统的方案,设计储能系统,并对主要元件参数进行计算.通过仿真分析可以看出:制动过程平稳、制动能量回收好,系统设计与元件参数的计算合理.%The background and application scope of hydraulic hybrid technology were described.The idea of hybrid hydraulic system design based on car's braking performance was put forward.The main elements parameters were calculated.Simulation results show that the braking process is smooth,brake energy is recovered better,the system design and parameter calculation are reasonable.

  7. Automotive mechatronics automotive networking, driving stability systems, electronics

    CERN Document Server

    2015-01-01

    As the complexity of automotive vehicles increases this book presents operational and practical issues of automotive mechatronics. It is a comprehensive introduction to controlled automotive systems and provides detailed information of sensors for travel, angle, engine speed, vehicle speed, acceleration, pressure, temperature, flow, gas concentration etc. The measurement principles of the different sensor groups are explained and examples to show the measurement principles applied in different types. Contents Basics of mechatronics.- Architecture.- Electronic control unit.- Software development.- Basic principles of networking.- Automotive networking.- Bus systems.- Automotive sensors.- Sensor measuring principles.- Sensor types.- Electric actuators.- Electrohydraulic actuators.- Electronic transmission control.- Electronic transmission control unit.- Modules for transmission control.- Antilock braking system.- Traction control system.- Electronic stability program.- Automatic brake functions.- Hydraulic modu...

  8. Optimization of actuator/sensor position of multi-body system with quick startup and brake

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new method was put forward to optimize the position of actuator/sensor of multi-body system with quick startup and brake. Dynamical equation was established for the system with intelligent structure of piezoelectric actuators. According to the property of the modes varying with time, the performance index function was developed based on the optimal configuration principle of energy maximal dissipation, and the relevant optimal model was obtained. According to its characteristic, a float-encoding genetic algorithm, which is efficient, simple and excellent for solving the global-optimal solution of this problem, was adopted. Taking the plane manipulator as an example, the result of numerical calculation shows that, after the actuator/sensor position being optimized,the vibration amplitude of the multi-body system is reduced by 35% compared with that without optimization.

  9. 汽车制动辅助系统的作用与特点分析%Analysis of the Functions and Features of Automobile Brake Assist System

    Institute of Scientific and Technical Information of China (English)

    麻友良; 程胭脂; 陈希

    2014-01-01

    Describes the existence of the problem of the automobile during emergency braking ,and the role of brake assist system and basic components.Analysis of the existing car brake assist system to produce maximum braking pressure way and characteristics.Pointed out that the ESP-based HBA will be the development direction of the automobile brake assist system.%本文阐述了汽车紧急制动时存在的问题及制动辅助系统的作用和基本组成,分析了现有的汽车制动辅助系统产生最高制动压力的方式及特点,指出基于ESP的HBA将是汽车制动辅助系统的发展方向。

  10. Designs on Electric Control Processes of Automotive Electric Parking Brake System%汽车电子驻车制动EPB系统电控流程设计

    Institute of Scientific and Technical Information of China (English)

    刘峰

    2016-01-01

    The author introduces the designs on the control principles and processes of automotive EPB electrical control system, including brake process, brake release process, ramp start process, emergency brake process and in-telligent brake process, in order to provide a reference for the application of the electronic parking brake system.%介绍汽车EPB电控系统原理与电控流程设计,包括制动流程、解除制动流程、坡道起步流程、紧急制动流程、智能制动流程等,为电子驻车制动系统的应用提供参考。

  11. Review on Composite Braking System of Electric Vehicle%电动汽车复合制动系统研究现状综述

    Institute of Scientific and Technical Information of China (English)

    熊璐; 钱超; 余卓平

    2015-01-01

    从原理、结构、特点、控制策略和制动动力学控制等方面阐述了电动汽车复合制动系统的发展现状,针对复合制动系统的3种结构型式(油门踏板型、未解耦型和解耦型)进行了对比分析,表明解耦型复合制动系统是未来复合制动系统的主要发展方向。重点分析了解耦型复合制动系统的控制策略,并且总结了正常制动和紧急制动2种工况下液压制动力和再生制动力的动态协调控制方法,最后提出复合制动对于液压制动系统的设计要求。%The development status of electric vehicle is discussed in term of theory, structure, characteristic, control strategy and braking dynamics control, etc.. And three composite braking system structures, i.e. the throttle pedal type, coupled type and decoupled type are analyzed and compared, which shows that the decoupled composite braking system represents the mainstream development trend of the composite brake system in the future. Control strategy of the decoupled composite braking system is the focus of analysis in this paper, and dynamic coordination control method of hydraulic braking and regenerative braking force in normal and emergency braking are summed up. The design requirements of the hydraulic braking system in composite brake are put forward in the end of this paper.

  12. 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.

  13. 汽车真空辅助制动系统的设计与研究%Design and Research of Automotive Vacuum Auxiliary Braking System

    Institute of Scientific and Technical Information of China (English)

    刘树伟; 郭立新; 郝亮

    2015-01-01

    以汽车紧急制动工况为研究对象,设计和研制了一种汽车真空辅助制动系统,该系统主要包括机械执行机构、制动吸盘、真空系统、弹射收起系统、控制系统五个部分。对该系统进行了理论分析和实验研究,结果表明,该系统可显著提高汽车制动效能,可有效缩短汽车紧急制动时的制动距离,从而有效降低交通事故的发生概率并降低交通事故的严重程度。%An automotive vacuum auxiliary braking system was designed when the driver urgently braked the automobile.The system mainly contained five parts,such as mechanical actuator,braking sucker,vacuum system,ejection retracting system,the control system and so on.The vacuum auxiliary braking system could increase significantly the braking efficiency and shorten the braking distance of automobile emergency braking.After the theoretical analysis and the experimental research,the sys-tem will reduce effectively the probability and the damage degree of traffic accidents.

  14. Signal Processing Experiment Analyses of Automotive Anti-lock Braking Systems%汽车防抱死制动系统信号处理实验分析

    Institute of Scientific and Technical Information of China (English)

    田玉冬; 夏群生

    2009-01-01

    针对汽车防抱死制动系统(ABS)严格的制动信号控制问题,分析了ABS的工作原理,进行了基于机理的ABS信号处理实验,详细给出了采用四轮汽车轮速传感器的ABS信号处理的结构、数据和算法.实验结果证明其快速准确,为ABS的系统控制提供了依据.

  15. The Processing of the Signal from Wheel Speed Sensor in Anti-lock Brake System%汽车防抱死制动系统轮速传感器信号处理

    Institute of Scientific and Technical Information of China (English)

    陈在峰; 宋键; 于良耀

    2000-01-01

    本文研究了汽车防抱死制动系统轮速传感器信号的处理问题.在对变磁阻激励式轮速传感器的工作特性进行试验研究的基础上,提出了对轮速传感器信号处理电路的要求,设计出了由两级迟滞比较器+低通滤波构成的信号处理电路.对电路进行了仿真和试验研究.研究结果显示,这种轮速信号处理电路工作可靠、抗干扰能力强.在较低车速下(<3km/h)仍能准确地测量车速.

  16. Research on the Hybrid Modeling and Simulation of the Anti-lock Braking System%汽车制动防抱系统的混合建模与仿真研究

    Institute of Scientific and Technical Information of China (English)

    孙骏; 朱忠奎; 尹安东; 羊拯民

    2004-01-01

    在分析汽车制动防抱系统(ABS)工作特点的基础上,指出汽车ABS是由连续系统与离散系统组成的混合系统,进而提出基于有限状态机与Matlab/Simulink的ABS混合建模方法.利用混合建模方法建立了某轻型客车的ABS仿真模型并进行了低附着系数道路条件下的仿真研究,探讨了制动器制动力、电磁阀响应时间和车轮转动惯量对汽车ABS性能的影响.仿真结果表明基于混合建模的ABS仿真系统能很好的模拟汽车ABS的性能;制动器制动力、电磁阀响应时间和车轮转动惯量对ABS制动性能影响的分析为ABS的设计提供了依据.

  17. 汽车ABS防抱死制动系统试验台的设计%Development and Design of ABS Anti-lock Brake System Test-bed for Automobile

    Institute of Scientific and Technical Information of China (English)

    吴良芹

    2013-01-01

    针对目前防抱死制动系统(ABS)产品试验过程中存在的问题,对汽车ABS性能试验台作了深入研究.为了给汽车ABS提供一种在实验室环境下经济高效合理的测试手段,设计出一种能够较为准确地模拟汽车实际工作情况的ABS制动试验台.介绍了该试验台的结构特点、设计原理及关健技术,为汽车ABS的试验和教学提供了新的解决方法.

  18. 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.

  19. An analysis of braking measures

    NARCIS (Netherlands)

    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.

  20. Research on the Feasibility of Application of ABS in Hydraulic Disc Brake%ABS在液压盘式刹车中应用的可行性研究

    Institute of Scientific and Technical Information of China (English)

    石固欧; 刘威

    2013-01-01

    The anti-lock braking system (ABS) of automobiles has such advantages as slippage and lock prevention,relatively short distance of braking and reduction of tyre wear.Therefore,the ABS control strategy was introduced to the design of the hydraulic system of drilling and workover rigs.The neotype hydraulic control system of hydraulic disc brake with both manual and automatic operation modes was built,which could achieve ABS control strategy.A comparative braking dynamic simulation analysis of the hydraulic system and running conditions with and without the ABS system was conducted.The analysis shows that selection of the proper duty cycle of the ABS system can get closer to the braking time and angle displacement without the ABS system.The better pressure regulation waveform had been obtained.Regulation of the ABS control strategy can obtain the ideal braking time and brake's braking torque.Therefore,the complex requirement of workover lifting system for operation process can be satisfied desirably.%汽车ABS防抱死刹车系统具有防滑防抱、制动相对距离短及能减轻轮胎磨损等优点.为此,将汽车ABS控制策略引入到钻(修)井机液压盘式刹车系统设计中,构建了具有手动/自动操作方式且能实现ABS控制策略的液压盘式刹车的新型液压控制系统,并对具有ABS系统与无ABS系统的盘式刹车分别进行液压系统与下入工况制动动力学仿真对比分析.分析结果表明,选择适当的ABS系统占空比,可以更接近无ABS系统刹车时间与角位移,并获得较好的压力调节波形,调整ABS控制策略可使系统获得理想的刹车时间与刹车制动力矩,从而能够较好地满足修井机起升系统作业过程的复杂要求.

  1. 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.

  2. Design And Implementation of Dsp-Based Intelligent Controller For Automobile Braking System

    Directory of Open Access Journals (Sweden)

    S.N. Sidek and M.J.E. Salami

    2012-08-01

    Full Text Available An intelligent braking system has great potential applications especially, in developed countries where research on smart vehicle and intelligent highways are receiving ample attention. The system when integrated with other subsystems like automatic traction control, intelligent throttle, and auto cruise systems, etc will result in smart vehicle maneuver. The driver at the end of the day will become the passenger, safety accorded the highest priority and the journey optimized in term of time duration, cost, efficiency and comfortability. The impact of such design and development will cater for the need of contemporary society that aspires to a quality drive as well as to accommodate the advancement of technology especially in the area of smart sensors and actuators.  The emergence of digital signal processor enhances the capacity and features of universal microcontroller.  This paper introduces the use of TI DSP, TMS320LF2407 as an engine of the system. The overall system is designed so that the value of inter-vehicle distance from infrared laser sensor and speed of follower car from speedometer are fed into the DSP for processing, resulting in the DSP issuing commands to the actuator to function appropriately.Key words:  Smart Vehicle, Digital Signal Processor, Fuzzy Controller, and Infra Red Laser Sensor

  3. Nonlinear transient vibrations and coexistences of multi-instabilities induced by friction in an aircraft braking system

    OpenAIRE

    Chevillot, Fabrice; Sinou, Jean-Jacques; Hardouin, Nicolas

    2009-01-01

    International audience Friction-induced vibration is still a cause for concern in a wide variety of mechanical systems, because it can lead to structural damage if high vibration levels are reached. Another effect is the noise produced that can be very unpleasant for end-users, thereby making it a major problem in the field of terrestrial transport. In this work the case of an aircraft braking system is examined. An analytical model with polynomial nonlinearity in the contact between rotor...

  4. 汽车主动空气阻力制动系统仿真研究%Simulation study on initiative sir power brake system of the vehicle

    Institute of Scientific and Technical Information of China (English)

    付强; 赵立杰; 孙雪玲

    2012-01-01

    针对汽车防抱制动时地面制动力存在极限值无法更有效的缩减制动距离问题,提出了新型汽车主动空气阻力制动(APB)系统,分析其工作原理并进行控制模型基础仿真研究.阐述主动空气阻力制动系统理论可行性,依据压缩空气喷气助力原理的反作用应用于汽车制动系统,利用MATLAB/Simulink建立新型汽车制动系统动力学模型和APB仿真模型.设计了仿真试验,对比实施APB控制的车速与轮速曲线,试验结果表明APB控制达到缩减制动距离和制动时间的目的.%A new vehicle air power brake system (APB)is put forwarded in this paper to resolve that the braking distance can t be effective curtailed because of the maximum ground braking force during vehicle braking.Then its working principle and research on the basic simulation of control model is analyzed, in which the academic feasibility of initiative air power brake system is expatiatedAccording to the principle of compressed air power reaction against the brake system,a dynamics model of a new automotive brake system and simulation model of ABS+APB are established based on MATLAB/Simulink.i4/ierw/a/Y the simulated tests are designed to compare with the curve of vehicle speed and wheel velocity with APB, which result indicates that the cehicle speed and wheel velcocity controlled by APB can reduce braking distances and braking time.

  5. Research on temperature rise of hoisting machine disk brake

    Institute of Scientific and Technical Information of China (English)

    MA Jun; JANG Hai-bo

    2012-01-01

    A mathematical model and finite element model for analysis of temperature rise of the hoisting machine brake system was constructed,limit conditions were defined,and the law of temperature rise of brake shoes during emergent brake course was analyzed and calculated by using finite element software.By analyzing the calculation results,the law of temperature change of surface of brake disk and shoes during the braking process was found.The law of brake shoes surface temperature distribution and the law of temperature change along with thickness of brake shoes at brake time 0.5 s,1.0 s and 1.5 s was analyzed.A hoisting machine emergent braking test was carried out.Finally,the author concluded that velocity rebound in the process of hoisting machine emergent brake is due to decreased friction coefficient caused by the temperature rise of the brake shoes surface.

  6. Central Queensland University's Course Management Systems: Accelerator or brake in engaging change?

    Directory of Open Access Journals (Sweden)

    Jeanne McConachie

    2005-03-01

    Full Text Available Central Queensland University (CQU is a highly complex institution, combining campuses in Central Queensland and distance education programs for Australian domestic students with Australian metropolitan sites for international students and a number of overseas centres, also for international students. In common with many other universities, CQU has recently reviewed its course management systems (CMSs. In doing so, CQU has signalled its desired strategic position in managing its online learning provision for the foreseeable future.This paper analyzes that strategic position from the perspective of the effectiveness of CQU’s engagement with current drivers of change. Drawing on online survey results, the authors deploy Introna’s (1996 distinction between teleological and ateleological systems to interrogate CQU’s current position on CMSs – one of its most significant enterprises – for what it reveals about whether and how CQU’s CMSs should be considered an accelerator of, or a brake on, its effective engagement with those drivers of change. The authors contend that a more thorough adoption of an ateological systems approach is likely to enhance the CMS’s status as an accelerator in engaging with such drivers.

  7. The Improvement of Hydraulic System in Press Brake%折弯机液压系统的改进

    Institute of Scientific and Technical Information of China (English)

    尹亮

    2011-01-01

    On the analysis of design faults in the hydraulic system for the 1000kN press brake, the design has been improved. The practice production shows that the improvement has a good effect.%在分析1000kN折弯机液压系统设计缺陷的基础上,进行了改进.经一段时间的生产表明,达到了预期效果.

  8. 78 FR 66101 - Jaguar Land Rover North America, LLC, on behalf of Jaguar Cars Limited, Grant of Petition for...

    Science.gov (United States)

    2013-11-04

    ... 26, 2011 in the Federal Register (76 FR 53532). No comments were received. To view the petition, and... brake warning and Antilock Braking System (ABS) failure warnings are displayed using International... sound. c. If an antilock brake system (ABS) malfunction is detected, the ISO ABS symbol...

  9. 驻车制动器的自锁保护装置%Self-locking Protection System of Hand brake

    Institute of Scientific and Technical Information of China (English)

    蒋晓琴

    2013-01-01

    The working conditions of central braking systems used in most automobiles are discussed.The reasons of the automobile sliding accident are analyze.And a simple improved design is put forward by adding a self-locking protection system,which is consist of electro-hydraulic control devices on the hand brake.While the self-locking protection system is working,the hand brake can not be released unless the ignition switch is turned on.%通过对汽车中央制动器的工作状态进行研究,分析了带中央制动器的汽车倒溜下滑的原因;提出了一种简单的改进设计方法,即在驻车制动器上加装一个带自锁功能的电液控制辅助装置,使得汽车在点火开关断开后,司机可以拉出手柄制动,但因自锁不能推回手柄解除制动,若要解除制动,必须先闭合点火开关,辅助装置的作用是要解除制动必须要点火开关闭合.

  10. Reduction of Noise from Disc Brake Systems Using Composite Friction Materials Containing Thermoplastic Elastomers (TPEs)

    Science.gov (United States)

    Masoomi, Mohsen; Katbab, Ali Asghar; Nazockdast, Hossein

    2006-09-01

    Attempts have been made for the first time to prepare a friction material with the characteristic of thermal sensitive modulus, by the inclusion of thermoplastic elastomers (TPE) as viscoelastic polymeric materials into the formulation in order to the increase the damping behavior of the cured friction material. Styrene butadiene styrene (SBS), styrene ethylene butylene styrene (SEBS) and nitrile rubber/polyvinyl chloride (NBR/PVC) blend system were used as TPE materials. In order to evaluate the viscoelastic parameters such as loss factor (tan δ) and storage modulus (E‧) for the friction material, dynamic mechanical analyzer (DMA) were used. Natural frequencies and mode shapes of friction material and brake disc were determined by modal analysis. However, NBR/PVC and SEBS were found to be much more effective in damping behavior. The results from this comparative study suggest that the damping characteristics of commercial friction materials can be strongly affected by the TPE ingredients. This investigation also confirmed that the specimens with high TPE content had low noise propensity.

  11. 城轨车辆制动控制系统的分析%Analysis of the brake control system for mass transit vehicles

    Institute of Scientific and Technical Information of China (English)

    何宝昌

    2012-01-01

    制动系统是城轨车辆关键系统之一,根据故障导向安全原则,制动系统失效时应有充足的措施确保列车和人员安全。北京地铁四号线车辆的制动控制系统通过G阀和RIO阀,完成列车的保持制动、常用制动、紧急制动、防滑保护等功能,并且将列车制动控制系统接入到TCMS系统中,保证了车辆的安全运营。%Brake system is critical to a mass transit vehicle, and there should be sufficient measures for this system to ensure train and personnel safety whenever it fails according to Failure Guiding & Safety Principle. By means of G valve and RIO valve, the brake control system of vehicles for Beijing Metro Line 4 can perform retaining brake, service brake, emergency brake and antiskid protection, and can connect train brake control system to TCMS system to ensure the safe operation of rail vehicles.

  12. Design of Disk Brake Monitoring System of Mine Hoist%矿井提升机盘形闸监控系统设计

    Institute of Scientific and Technical Information of China (English)

    曾盈; 孙伟; 孙浩

    2012-01-01

    A disk brake monitoring system of mine hoist to real-timely monitor three parameters of brake clearance, braking force and idle motion time was designed based on the three parameters can reflect braking performance of disk brake of mine hoist. The system uses two micro-processers, one is used to measure brake clearance and finish functions transform, the other is used to measure idle motion time and braking force. And it uses fault diagnosis technology based on expert system to judge abnormal states of disk brake running. The actual application showed that the system has high measuring precision, good real-time performance and high reliability.%基于闸间隙、制动力和空动时间这3个参数可全面反映矿井提升机盘形闸的制动性能,设计了一种可实时监控这3个参数的矿井提升机盘形闸监控系统.该系统采用2个微处理器,一个用来测量闸间隙并完成一些功能转换,另一个用来测量空动时间和制动力;并采用基于专家系统的故障诊断技术判断盘形闸在运行过程中出现的异常状态.实际应用表明,该系统具有检测精度高、实时性好、可靠性高等特点.

  13. Handbook of driver assistance systems basic information, components and systems for active safety and comfort

    CERN Document Server

    Hakuli, Stephan; Lotz, Felix; Singer, Christina

    2016-01-01

    This fundamental work explains in detail systems for active safety and driver assistance, considering both their structure and their function. These include the well-known standard systems such as Anti-lock braking system (ABS), Electronic Stability Control (ESC) or Adaptive Cruise Control (ACC). But it includes also new systems for protecting collisions protection, for changing the lane, or for convenient parking. The book aims at giving a complete picture focusing on the entire system. First, it describes the components which are necessary for assistance systems, such as sensors, actuators, mechatronic subsystems, and control elements. Then, it explains key features for the user-friendly design of human-machine interfaces between driver and assistance system. Finally, important characteristic features of driver assistance systems for particular vehicles are presented: Systems for commercial vehicles and motorcycles.

  14. THE ASSESSMENT OF BASIC TECHNICAL PARAMETERS OF THE COOLING SYSTEM OF THE LOCOMOTIVE DISK BRAKE

    Directory of Open Access Journals (Sweden)

    I. M. Biloborodova

    2009-04-01

    Full Text Available In the article a thermal (constructive calculation of the liquid-air recuperative heat exchanger is executed. Its purpose was an estimation of the areas of heat-exchange surfaces and the consumption of heat carriers necessary for dissipation of thermal energy generated by a locomotive disk brake.

  15. The Electronic Wedge Brake - EWB

    Energy Technology Data Exchange (ETDEWEB)

    Ho, L.M.; Roberts, R.P.; Hartmann, H.; Gombert, B. [Siemens VDO Automotive (Germany)

    2006-07-01

    Future driver assistance systems will not only monitor the current traffic situation, but actively assist the driver in the day to day driving routines and as well in emergency situations. Autonomous intervention in the vehicle behavior will help to keep the vehicle under control, even in hazardous situations. A fast and smart braking system is one of the basics for the next generation of driver assistance systems. Siemens VDO sees its electronic wedge brake (EWB) brake-by-wire technology as the answer to future vehicle chassis safety, weight, reliability and space requirements. Particularly in the automobile sector, there is an increasing trend towards replacing existing hydraulic or pneumatic brake systems with drive 'by-wire' solutions. While mechatronics, i.e. intelligent, controllable electromechanical actuators, are already in use in many automotive and non automotive areas, there are particularly strict requirements for purely electromechanical braking systems which require complex development processes. These are highly safety critical systems, which must provide both excellent control quality and sophisticated fail-safe behavior. The challenge is to achieve a high power density in the wheel brake actuators. (orig.)

  16. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Train brake tests conducted using yard air. 232... Train brake tests conducted using yard air. (a) When a train air brake system is tested from a yard air... reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The...

  17. 提升机闸瓦温度监测系统的研究%Temperature Monitoring System Research of Hoist Brake Shoe

    Institute of Scientific and Technical Information of China (English)

    沙永东; 李晓豁; 康晓敏; 侯静

    2012-01-01

    In order to effectively protect hoist brake shoe' s braking performance,improve the work reliability and service life, establishing temperature monitoring system of hoist brake shoe in braking process.This system consists of detection system and alarm, communication lines,host computer,etc. ,can be for hoist brake shoe online measurement temperature and real--time monitoring,with low energy consumption,small size,reliability and stability,information processing ability and other characteristics. The system for staff to provide effective reference data,can be according to the monitoring results related parameters in the fixed,ensure brake shoe under the premise of performance improved the safety and reliability of the brake system.%为了有效地保护提升机闸瓦的制动性能、提高其工作可靠性和使用寿命,建立了提升机闸瓦在制动过程中的温度监测系统,该系统由检测系统及报警器、通讯线路、上位机等组成,能对提升机闸瓦温度进行在线测量和实时监控,具有能耗低、体积小、可靠性和稳定性好,信息处理能力强等特点,该系统为工作人员提供了有效数据参考,可以根据监测结果及时进行相关参数的修正,在保证闸瓦性能的前提下提高了制动系统的安全可靠性。

  18. The development of the brake system for the Mercedes-Benz Vito; Entwicklung der Bremsanlage fuer den Vito von Mercedes-Benz

    Energy Technology Data Exchange (ETDEWEB)

    Reuter, M.; Spielmann, W.

    1996-05-01

    The new Mercedes Vito is a vehicle which was designed to meet both the requirements of tough city van operation and the sophisticated demands of private buyers seeking a car-like multi-purpose vehicle. The vehicle is fitted with disc brakes all round and, in the majority of the European markets, with ABS/ABD as standard. Its hydraulic brake system, using floating-caliper wheel brakes, is diagonally divided and equipped with a vacuum brake booster and automatic load-sensing brake pressure control. In addition to meeting the customary requirements made on van brakes, the target in development was to fulfil the higher demans made on car brakes in terms of comfort and high speed. For the first time, system development was commissioned to the brake manufacturer ITT Automotive Europe; this step followed logically from the approach adopted in the development of the brake system for the Sprinter. As a result of this approach, the scope of brake testing performed by the vehicle manufacturer was substantially reduced. Close cooperation also permitted the vehicle manufacturer to gain sufficient know-how so as to be able to control future developments in a target-oriented manner. The prerequisite for this is the existence of Detailed specifications dockets for Development and testing, including requirement profiles, test programs, test specifications and schedules. The positive results of testing prior to the approval for series production and problem-free operation during large-scale testing by customers prove that this approach can also be applied to future projects. (orig.) [Deutsch] Der neue Vito von Mercedes-Benz ist serienmaessig mit vier Scheibenbremsen und fuer die meisten europaeischen Maerkte mit ABS und ABD ausgeruestet. Zum Einsatz kommt eine diagonal aufgeteilte hydraulische Bremsanlage mit Vakuum-Hilfskraftunterstuetzung und automatisch lastabhaengiger Bremskraftaufteilung (ALB). Als Radbremsen werden an der Vorderachse Faustsattelbremsen, an der Hinterachse

  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. Emergency braking systems for commercial vehicles in various markets shown for Europe and the USA; Marktspezifische Notbremssysteme im Nutzfahrzeug am Beispiel Europa und USA

    Energy Technology Data Exchange (ETDEWEB)

    Breuer, Karsten; Hoffmann, Guido; Sandkuehler, Dirk [WABCO, Hannover (Germany)

    2008-07-01

    Today the main focus of driver assistance in commercial vehicles changes from pure comfort systems to safety related systems. Currently most development work is taking place for collision avoidance and collision mitigation systems, which is caused by various initiatives of the legislation organizations around the world. Since the world's markets have differing requirements, those systems are varying in their concept and design. In the following course a concept for autonomous braking in collision immanent situations and its different implementations are shown for systems in Europe and the USA. Especially the different integration into the vehicle electronic architecture and the brake control is described. (orig.)

  1. The brake-system of the new Mercedes van-generation Sprinter; Die Bremsanlage der neuen Transporter-Generation Sprinter von Mercedes-Benz

    Energy Technology Data Exchange (ETDEWEB)

    Reuter, M.; Spielmann, W.

    1996-01-01

    The new Mercedes-Sprinter is the first van model series in this weight category which is equipped with disc brakes all round and ABS und ABD as standard. A diagonally divided hydraulic brake system with vacuum-controlled power assistance and automatic load-sensitive brake pressure control (ALB) is installed. The wheel brakes used are of a floating caliper type. During the development particular attention was paid to the constant friction coefficient of the brake linings, the `high` speed suitability and the provision of high thermal reserves. This concept offers good prerequisites for adding additional functions such as a brake assistant or a dynamic handling control system. For the first time there was a close cooperation between vehicle manufacturer, suppliers of brakes, linings and components during the development phase. To organise this complex development work a comprehensive specification booklet with detailed specs was drawn up and agreed with all parties involved. The result of the close cooperation is a positive example of the Mercedes-Benz tandem philosophy. (orig.) [Deutsch] Beim neuen Mercedes-Sprinter handelt es sich um die erste Transporter-Baureihe in dieser Gewichtsklasse mit vier Scheibenbremsen und serienmaessigem ABS mit ABD. Zum Einsatz kommt eine diagonal aufgeteilte hydraulische Bremsanlage mit Vakuum-Hilfskraftunterstuetzung und automatisch lastabhaengiger Bremskraftregelung (ALB). Als Radbremsen werden Schwimmsattelbremsen in Faustsattelbauweise verwendet. Besondere Schwerpunkte bei der Entwicklung waren die Reibwertkonstanz der Bremsbelaege, die Tauglichkeit bei hohen Geschwindigkeiten und die Schaffung hoher thermischer Reserven. Mit dieser Konzeption sind gute Voraussetzungen geschaffen, um weitere Zusatzfunktionen wie etwa einen Bremsassistenten oder eine Fahrdynamikregelung einzusetzen. Bei der Entwicklung wurde erstmals eine enge Zusammenarbeit zwischen Fahrzeughersteller, Bremsen-, Belag- und Komponentenlieferanten praktiziert. Zur

  2. Ultrasonic Sensors in Urban Traffic Driving-Aid Systems

    Directory of Open Access Journals (Sweden)

    Teresa de Pedro

    2011-01-01

    Full Text Available Currently, vehicles are often equipped with active safety systems to reduce the risk of accidents, most of which occur in urban environments. The most prominent include Antilock Braking Systems (ABS, Traction Control and Stability Control. All these systems use different kinds of sensors to constantly monitor the conditions of the vehicle, and act in an emergency. In this paper the use of ultrasonic sensors in active safety systems for urban traffic is proposed, and the advantages and disadvantages when compared to other sensors are discussed. Adaptive Cruise Control (ACC for urban traffic based on ultrasounds is presented as an application example. The proposed system has been implemented in a fully-automated prototype vehicle and has been tested under real traffic conditions. The results confirm the good performance of ultrasonic sensors in these systems.

  3. 风轮机液压制动控制系统的研究%Research on Hydraulic Braking Control System of Wind Turbine

    Institute of Scientific and Technical Information of China (English)

    张文亭

    2015-01-01

    该文分析了风轮机常用的制动系统和控制系统,设计了基于紧急情况下的风轮机液压制动系统,并通过实验进行了测试,最后进行了紧急情况下的数据仿真研究,指出本制动器在不同最大设置压力和初始转速条件下的制动性能。%This paper analyses common braking system and control system in wind turbine, designs the hydraulic brake system of wind tur-bine based on emergency cases,and verified by experiment, also studies on the data simulation in case of emergency, points out the brake performance at different maximum set pressure and initial speed conditions.

  4. 浅析逆向注油排气法在汽车液压制动系统中的应用%On the Application of Reverse Oiling and Exhaust Method in Automotive Hydraulic Braking System

    Institute of Scientific and Technical Information of China (English)

    曹志维

    2014-01-01

    Automotive hydraulic braking system is the automotive braking device by using the brake fluid as the transmission media to make the wheel brakes work. The hydraulic braking system has the advantages of smooth braking and high sensitivity. Once the hydraulic braking system occur air resistance, it will cause braking weak, the braking force reducing and other failure, and reduce the braking performance of wheel brakes, so that will directly affects the car's braking performance and safety. This paper introduces an operation method overturning the traditional methods:reverse oiling and exhaust method. This method is simple and practical, and can greatly improve the maintenance efficiency.%汽车液压式制动系统是利用制动油液作为传力介质使车轮制动器工作的汽车制动装置,液压式制动系统具有制动平稳、制动灵敏度高等优点。而当液压制动系统一旦发生气阻时就会导致制动发软、制动力减小等故障,使车轮制动器的制动效能下降,直接影响汽车的制动性能和安全性。文章介绍一种颠覆传统操作方法:逆向注油排气法,这种方法简单实用,极大地提高了维修效率。

  5. 新款三轮运动车制动系统设计%Design of Brake System of New Three-wheel Sports Car

    Institute of Scientific and Technical Information of China (English)

    田锐; 李桂华

    2012-01-01

    Through the braking performance analysis for new three-wheel sports car,the paper designed and calculated the structure of floating type disc brake in braking system and fully hydraulic braking drive system by human power.According to GB 7258-2004"safety specification for power-driven vehicles operating on road",its performance is verified,and the design result is good.And so the braking requirements of three-wheel sports car in ideal pavement is also met.%通过对新款三轮运动车制动性能要求进行分析,设计计算了制动系统的浮钳形盘式制动器结构和采用人力操纵的全液压制动驱动系统,并根据《机动车运行安全技术条件》(GB 7258-2004)进行了验证,达到了设计效果,满足了三轮运动车在理想路面上的制动要求。

  6. CFD Analysis Of Straight Ventilated Disc Brake

    Directory of Open Access Journals (Sweden)

    Nikhil K

    2016-05-01

    Full Text Available Brakes are the key pieces of a vehicle that plays an active role in safety and performance of the system. The study of aerodynamic cooling of a disc brake in real working condition of vehicle is important in present situations. Brake discs get very hot quickly, so it should be dissipated properly through different modes of heat transfer. Contributions of these heat transfer modes are different in different type of problems. The cooling transfer rates are different in vane surface and frictional surface of a disc brake. Also the temperature varies in each small interval of braking time. So a transient problem simulation is important to study the cooling of a disc brake when a vehicle decelerates from a particular speed. ANSYS CFX tool is used for the simulation of this transient problem.

  7. 防抱死制动系统应用研究及参数设计%Anti-lock Braking System Application Research and Its Parameter Design

    Institute of Scientific and Technical Information of China (English)

    林瑾

    2014-01-01

    Vehicle emergency braking often brings about wheel lock ,while the anti‐lock braking system can be used for its improvement . The paper explained the working principle of the mechanical braking system structure and analyzed and calculated the main parameters .The re‐sults would be applied into practice to solve the problems in practical application .%针对车辆紧急制动时易产生车轮抱死的现象,运用防抱死制动系统对其改进,阐述机械式防抱死系统的工作原理及结构组成,对其主要参数进行分析和推算,并将研究成果运用到实例中,有效解决实际运用中的问题。

  8. High torque, high impact braking system by using Hot Melt Adhesive (HMA)

    OpenAIRE

    Fernandez Bocanegra, Juan José

    2011-01-01

    When designing a new legged robot it is important to think about what the robot has to do. It is not the same a non-stop walking robot than a legged robot which has to be at the same position much longer than moving. For the second kind of robot, it could be a great improvement to add a break in each actuated joint, so it is not necesary to wasted energy during the stoped time. And not only that, thanks to the brake, it is possible to achive heavier loads using a speci c wal...

  9. 14 CFR 27.921 - Rotor brake.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor brake. 27.921 Section 27.921... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  10. 14 CFR 29.921 - Rotor brake.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rotor brake. 29.921 Section 29.921... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 29.921 Rotor brake. If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations...

  11. Adaptive Noise Cancellation Method Used for Wheel Speed Signal of Integrate ABS/ASR System

    Institute of Scientific and Technical Information of China (English)

    MA Yue-feng; LIU Zhao-du; QI Zhi-quan; CUI Hai-feng

    2006-01-01

    A novel adaptive noise cancellation method for wheel speed signal of the anti-lock braking system/anti-slip regulation(ABS/ASR) control system is proposed. Based on the spectrum distribution of vehicle's wheel speed signal got from fast Fourier transform under various conditions, the high-pass filter is used to deal with original wheel speed signals sampled to get reference noise signal and the original wheel speed signals are used as adaptive filter's desired outputs. The difference between original signals and reference noise signals is used as the error signal for the adaptive FIR filter and also used as the whole adaptive noise cancellation system's final output. This method can obtain the noise signal on-line and is easy to use for real control system,which is useful to improve the performance of integrate system ABS/ASR.

  12. 49 CFR 236.712 - Brake pipe.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake pipe. 236.712 Section 236.712 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.712 Brake pipe. A...

  13. Control Circuit Design for Electronic Parking Brake System%电子驻车制动系统控制电路设计

    Institute of Scientific and Technical Information of China (English)

    郑婷; 王洪亮; 王显会; 皮大伟

    2014-01-01

    Based on the research status of electronic parking brake system at home and abroad and the function analysis of electronic parking brake system ,the overall design of a cable-type electronic parking brake system was carried out .The gradient sensor ,motor speed sensor and parking pulling sensor were selected ,and each module circuit was designed .The real vehicle matching and the parking/removing function debugging in variable drive conditions were completed .The results show that the static and dynamic characteristics of the electronic parking brake system can meet the design requirements .%在结合目前国内外电子驻车制动系统研究现状以及对其功能要求分析的基础之上,针对钢索牵引式电子驻车制动系统进行整体设计。依次对倾角传感器、电机转速传感器和拉力传感器等进行选型并完成各模块的电路设计;完成实车匹配并根据驾驶员实际操作以及各种车况进行驻车制动或解除的功能调试,结果表明其静态特性和动态特性均满足设计要求。

  14. An analysis of the annual probability of failure of the waste hoist brake system at the Waste Isolation Pilot Plant (WIPP)

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, M.A. [Univ. of California, Los Angeles, CA (United States); Sargent, T.J.

    1995-11-01

    The Environmental Evaluation Group (EEG) previously analyzed the probability of a catastrophic accident in the waste hoist of the Waste Isolation Pilot Plant (WIPP) and published the results in Greenfield (1990; EEG-44) and Greenfield and Sargent (1993; EEG-53). The most significant safety element in the waste hoist is the hydraulic brake system, whose possible failure was identified in these studies as the most important contributor in accident scenarios. Westinghouse Electric Corporation, Waste Isolation Division has calculated the probability of an accident involving the brake system based on studies utilizing extensive fault tree analyses. This analysis conducted for the U.S. Department of Energy (DOE) used point estimates to describe the probability of failure and includes failure rates for the various components comprising the brake system. An additional controlling factor in the DOE calculations is the mode of operation of the brake system. This factor enters for the following reason. The basic failure rate per annum of any individual element is called the Event Probability (EP), and is expressed as the probability of failure per annum. The EP in turn is the product of two factors. One is the {open_quotes}reported{close_quotes} failure rate, usually expressed as the probability of failure per hour and the other is the expected number of hours that the element is in use, called the {open_quotes}mission time{close_quotes}. In many instances the {open_quotes}mission time{close_quotes} will be the number of operating hours of the brake system per annum. However since the operation of the waste hoist system includes regular {open_quotes}reoperational check{close_quotes} tests, the {open_quotes}mission time{close_quotes} for standby components is reduced in accordance with the specifics of the operational time table.

  15. Improvement of Brake System of XJ-650 Workover Rig%XJ-650型修井机绞车制动系统改进

    Institute of Scientific and Technical Information of China (English)

    赵有清

    2015-01-01

    The working principle of hydraulic disc brake system of the hydraulic disc brake system is described in this paper.The problem of the existence of the pneumatic control belt brake for the XJ-650 type of the well is put forward.The hydraulic disc brake system of the workover rig is a-dapted for technological reformation,which is suitable for workover operation in deep and com-plex well conditions,and the construction of the labor intensity is decreased,security is obviously enhanced.%简述了修井机液压盘式刹车系统的工作原理。指出现有 XJ-650型修井机的气控带式刹车存在的问题。采用液压盘式刹车系统对该修井机进行技术改造,适应深井、复杂工况井等修井作业要求,并且使施工的劳动强度下降,安全性明显增强。

  16. Experimental Identification of Brake Pad Material Properties—A Step Towards a Better Prediction of Brake Squeal

    Science.gov (United States)

    Hornig, Sylwia; Hochlenert, Daniel; von Wagner, Utz

    2010-09-01

    Automotive brake squeal is a disruptive high frequency sound radiation phenomenon generated by friction-induced self-excited vibrations of the brake system. The brake system loses its stability and starts oscillating in a limit cycle with amplitudes limited by nonlinearities, the main origin of the nonlinearities being brake lining material. In order to perform a reliable brake squeal prediction using established mathematical-mechanical models, the knowledge of the lining material properties is of great importance. The present paper deals with the experimental identification of lining material properties, expecially referring to the elastic properties. Since these strongly vary depending on the operating conditions of brake systems, it is necessary to reproduce the operating conditions during brake squeal as close as possible in experimental setups. In this context a special test rig, the test data evaluation and the experimentally determined nonlinear elastic brake lining properties are presented. Assuming these brake lining properties to be the prominent source of the nonlinearity, a nonlinear stability analysis is performed on a realistic disk brake model. The results referring to brake squeal are discussed, whereas basic phenomena known from operating experience of brake systems can be explained on the basis of this analysis.

  17. 基于LabVIEW的汽车ABS测试系统设计%Design of ABS Testing System Based on LabVIEW

    Institute of Scientific and Technical Information of China (English)

    张文广; 杜春臣; 司利增

    2012-01-01

    ABS是汽车的一种重要主动安全装置.以图形化编程软件LabVIEW为核心,结合数据采集卡,设计了汽车ABS测试系统.该系统能够实现制动车速、制动距离、角速度、滑移率等性能参数的实时显示与存储,便于对ABS性能进行分析以及对控制算法进行优化改进,从而为开发和研制汽车防抱死制动系统提供了测试依据.%ABS is an important active safety device in a vehicle. This paper uses the graphical programming software LabVIEW as the core and combines the data acquisition card to design the car ABS testing system. The braking performance real-time display and storage such as braking speed, braking distance, angular velocity and slip rate can be realized ,in order analyze the ABS performance and improve the control algorithm. Form this the testing basis is provided for the development of automobile anti-lock braking system and its research.

  18. Research of the Brake Parking Problem of Industrial Sewing Machine System%工业缝纫机系统制动停车问题研究

    Institute of Scientific and Technical Information of China (English)

    边淳; 郗晓田; 文小琴; 游林儒

    2012-01-01

    order to improve the efficiency of industrial sewing machine system based on brushless dc motor control, simplified brake method and simplify the brake method, this paper put forward a new kind of reversing lock brake parking control method about the brushless dc motor control industrial sewing machine system. This method analyzed from the two aspects of speed and braking, PI speed control method is used, detecting needle position signal for reversing locking brake, and demonstrated the feasibility of this control method in theory. Finally, presents a practical control rendering. Practice proves that the method has achieved good effect, met the control requirements of the industrial sewing machine system and improves the dynamic performance of the system.%为提高基于直流无刷电机控制的工业缝纫机系统的制动效率、简化制动方法,提出了一种新型的基于无刷直流电机控制的工业缝纫机系统换向锁定制动停车控制方法.该方法从调速、制动两方面人手,采用PI调节降速,通过检测停针位信号进行换向锁定制动.同时从理论方面分析论证了该控制方法的可行性,并给出了实际的控制效果图.实践证明:该方法取得了良好的控制效果,完全满足工缝机系统的控制要求,提高了系统的性能.

  19. Safety design and matching analysis of electronic hydraulic brake system%电子液压制动系统的安全设计与匹配分析

    Institute of Scientific and Technical Information of China (English)

    胡东海; 何仁

    2015-01-01

    The design of the electronic hydraulic brake system in general is lack of theoretical guidance. In this experiment, the structure and working principle of the electronic hydraulic brake system were analyzed in detail. Then the matching design method for the electronic hydraulic brake system based on safety feature was proposed on the basis of establishment of the mathematical model, including the design of power supply based on the hardware failure protection, the design of emergency brake circuit based on power supply failure protection, the design of the inlet and outlet valves based on the emergency braking requirements. The effectiveness of mathematical model was validated through the experiments, and the braking performance of electronic hydraulic brake system in both the common brake and hardware failure was analyzed. The hardware in loop test results showed that the booster response time of electronic hydraulic brake system was reduced when compared with the conventional hydraulic brake system under the normal braking. The electronic hydraulic brake system could control the wheel slip ratio in high adhesion road, low adhesion road and docking the road very well under emergency braking. Also, after using the accumulator brake vigorously for five times, the accumulator pressure was not less than the minimum system pressure in the case of electrical failure indicating that the design of accumulator met the requirements. In addition, the booster response time increased in the case of accumulator failure showing that although the motor pressure rated was higher than the system maximum working pressure but it had low flow rate. Furthermore, in the accumulator and the motor failure cases, the electronic hydraulic brake system still could provide part of the braking intensity which was higher than design required 3 m/s2 braking deceleration. Conclusions from the research included the accumulator should guarantee to complete several intensive braking under the

  20. 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.

  1. Finite element analysis of advanced bicycle precision brake disk forming technology

    Directory of Open Access Journals (Sweden)

    Chen Dyi-Cheng

    2015-01-01

    Full Text Available In recent years, the bicycle has become an environmentally friendly transportation. The bicycle can be divided into mountain bicycle and highway bicycle. Safe driving is the prior consideration. The bicycle braking system can be divided into oil pressure disk brakes and mechanical disk brakes. The brake disk system is one indispensable component of the safe system. In accordance to overall weight consideration of the bike, the brake disk should also focus on the lightweight design. This paper discussed an innovative brake disk forming technology for 6061 aluminum alloy by the rigid-plastic finite element analysis. The simulation parameters include geometric shapes of the brake disk and mold, die temperature, and friction factors. The stress and strain in forming, brake deformation and vibration modal analysis of brake disk in riding were studied. The paper is expected to offer some precision bicycle brake disk manufacture knowledge for industry.

  2. Analysis on Handling Stability Simulation of SUV at the condition of Braking based on CarSim software%防抱死制动系统对SUV车辆操控稳定性仿真分析

    Institute of Scientific and Technical Information of China (English)

    朱崇敬; 郭朋彦; 张瑞珠; 冯金泉; 马付屹

    2015-01-01

    Aiming at the phenomenon that Sport Utility Vehicles will lose its stability and the steering ability will become bad in case of Emergency Braking, CarSim software is applied to establish full vehicle dynamic model in which the whole driving process of Emergency Braking condition is simulated, preliminary finding ABS system has a big influence on handling stability at this condition. For further validating, the collaborative simulation model is set up combining Carsim with Simulink, the numeric changes of slip angle, yaw and offset can be plotted, which reflect handling stability most under the input of braking pressure. After analyzing and making comparisons about testing data, the goal of improving handling stability by installing anti-lock braking system to SUV in case of emergency braking is determined. Finally the purpose of driving safely can be met.%针对SUV车辆在制动情况下出现的操纵性和稳定性变差现象,在CarSim软件中建立了SUV车辆动力学模型,在对开的路面对行驶的紧急制动工况进行了仿真,初步发现防抱死系统对该工况下车辆操纵稳定性的影响最大,为进一步验证,与Simulink结合建立了整车联合仿真模型,将Carsim中SUV制动过程中的制动压力导出至Simulink模型作制动仿真测试,进一步描绘出车轮侧偏角、横移角速度和偏移位移等影响操纵稳定性的参数数值变化曲线,通过分析对比,确定了紧急制动条件下为SUV车辆加装防抱死系统能达到提高操纵稳定性的目标,最终达到安全驾驶的目的。

  3. Design and Analysis of Hydraulic System of Disc Brake for Downward Belt Conveyor%下运带式输送机盘式制动器液压系统设计与分析

    Institute of Scientific and Technical Information of China (English)

    刘灿杰; 贾跃虎; 刘志奇

    2011-01-01

    通过分析下运带式输送机制动工况的特点以及盘式制动器的优点,设计出适合各制动工况要求的新型盘式制动器液压系统.该液压系统具有松闸、保压、正常停车制动、超速制动、紧急制动和系统突然断电制动等功能.建立了系统的数学模型,将数学模型线性化后推导出了系统传递函数,分析了各元件参数对系统响应性的影响,为设计压力精细调节的制动器提供了理论基础.%The characteristics of braking condition of downward belt conveyor and advantages of disc brake were analyzed. A new hydraulic system of disc brake which met each braking condition requirement was designed. This hydraulic system have functions of loose braking, the normal parking braking, emergency braking and suddenly lose power braking. The mathematical model of this hydraulic system was established. The transfer function of this hydraulic system was deduced by the mathematical model linearization. The influences of the parameters to the response of the system were analyzed. The research work lays theory foundation for the design of brake with pressure fine adjustment.

  4. Muzzle brakes and their performance

    Directory of Open Access Journals (Sweden)

    J. P. Sirpal

    1958-01-01

    Full Text Available A criteria for the usefulness of a muzzle brake on any equipment is discussed and applied to existing weapons. Efficiencies of the existing muzzle brakes are also calculated. Design considerations for a muzzle brake are summarized.

  5. Coordination control strategy of electric vehicle hybrid brake system in transient conditions%电动汽车复合制动系统过渡工况协调控制策略

    Institute of Scientific and Technical Information of China (English)

    朱智婷; 余卓平; 熊璐

    2014-01-01

    液压制动与电机再生制动互相切换的过渡工况控制是电动汽车复合制动系统控制需要解决的关键技术问题,直接影响到驾驶员的制动感觉与车辆制动舒适性。对此提出一种协调控制策略,包括制动力分配修正和电机力补偿2个模块。制动力分配修正模块针对液压制动力介入、撤出和再生制动力低速撤出3类典型过渡工况修正分配结果;电机力补偿模块利用电机系统迅速准确的响应来补偿液压系统,改善复合系统的响应。对各类典型制动过渡工况进行仿真验证,结果表明,所设计的协调控制策略能有效减小实际总制动力波动和偏差,改善驾驶员的制动感觉和车辆制动舒适性。%The control in transient conditions when hydraulic brake and regenerative brake switch mutually is the key technical issue about electric vehicle hybrid brake system, which has a direct influence on the braking feel and braking comfort of a driver. A coordination control system has been proposed, including brake force distribution cor-rection module and motor force compensation module. The former fixes the distribution results in hydraulic brake force intervention condition, hydraulic brake force evacuation condition and regenerative brake force low speed e-vacuation condition. The latter compensates for the hydraulic system with motor system, which has fast and accurate response, thus the response of the whole hybrid system can be improved. Simulation and test results in transient conditions show that the coordination control strategy can effectively reduce the fluctuations and deviations of the to-tal brake force, and improve braking feel and braking comfort of a driver.

  6. 纯电动汽车电液制动系统再生制动控制策略分析研究%Analysis and Research on the Regenerative Braking Control Strategy of Pure Electric Vehicles Electric Liquid Brake System

    Institute of Scientific and Technical Information of China (English)

    吴静波; 郭志军; 申彦杰

    2015-01-01

    制动能量回馈是电动汽车特有的功能之一,即电动汽车在制动时,驱动电机处于发电状态,可为电池充电,从而实现制动能量的再生利用。通过对电液制动系统再生制动控制进行研究,减少了运行中的动力浪费,延长了纯电动汽车的使用寿命。因此,应根据纯电动汽车现有的电液制动系统,设定有效的再生制动控制策略,从而完善纯电动汽车的构造,实现更高的舒适性。%The regenerative braking is one of the features of electric cars would have a special, namely electric vehicle during braking, driving motor is in the state of power, to charge the battery, so as to realize the braking energy regeneration and utilization. The research on regenerative braking control of electro hydraulic braking system is carried out, which reduces the power waste and prolongs the service life of electric vehicle. Therefore, we should set up the effective regenerative braking control strategy according to the existing electro liquid brake system of pure electric vehicle, so as to improve the structure of pure electric vehicle and achieve higher comfort.

  7. 汽车EPB系统控制原理研究%Researches on Control Principles of Automotive Electric Parking Brake EPB System

    Institute of Scientific and Technical Information of China (English)

    刘峰

    2016-01-01

    汽车电子技术的不断进步,令驻车制动系统即手制动系统从过去机/液式的,逐渐变成电子式的。电子驻车制动可在行车前自动释放或在熄火后自动拉紧,省去了忘记解除驻车制动或“坡起”溜车等情况的困扰与风险;由于电子驻车制动系统即EPB系统的结构较为复杂,需要对其控制原理进行分析研究,本文主要包括EPB的组成及工作原理等。%With the automobile’s and electrical technology constantly development, the parking brake system is changing from the primary mechanical, hydraulic into electrical. Electric parking brake (EPB) system is able to release it before ignoring or strain it after stopping the engine automatically, and cuts the dififculties and dangerous rates of forgetting to be released or the slide on the slope; Because of the automotive EPB frame is so complex, the electrical brake system needs to analysis. This thesis is mainly contains the EPB structures and working principles.

  8. 动车组ATP对制动系统故障后的安全影响仿真分析%Simulation Analysis of Safety Affect of EMU’s ATP after Braking System Failure

    Institute of Scientific and Technical Information of China (English)

    曾庆晖; 谭丽

    2015-01-01

    With focus on the failure of part of the EMU vehicles’ brake system and the application of“closed door” measures, this paper simulates train protection algorithm and braking process in completely monitor mode, analyzes the algorithm of protection curves in single speed limit sections and multiple speed limit sections and the relationship between the actual braking curve and speed protection curve after cutting off partial breaking force based on protection curve generation and actual braking process and finds out the trigger points of all kinds of brakes. This paper calculates the braking distance with different slopes, initial braking speed and removal rate of braking by simulating actual braking curve after removal of different rate of braking force. In view of the potential excessive braking distance and signal intruding due to the failure removal, an ATP safety protection method to cope with brake system failure is put forward with reference to protection curve generation mechanism, and the effect of this method on line capability is analyzed.%针对动车组部分车辆制动系统故障后,采取切除故障车辆制动力的处理方式,从安全防护曲线的生成与实际制动过程的角度出发,对在完全监控模式下的列车防护算法及制动过程进行仿真。分析单限速区段和多限速区段速度防护曲线的算法和切除部分制动力后实际制动曲线与速度防护曲线的关系,找到触发各类制动的转换点,对切除不同比例制动力后实际制动曲线进行仿真,得出不同坡度和制动初速度下、切除不同比例制动力时的制动距离。针对动车组因故障切除部分制动力后,产生过走距离,存在冒进信号点的可能,参照防护曲线生成机理,给出兼顾制动力故障的ATP安全防护方法,分析按该方法运行时对通过能力的影响。

  9. Electromagnetic braking for Mars spacecraft

    Science.gov (United States)

    Holt, A. C.

    1986-01-01

    Aerobraking concepts are being studied to improve performance and cost effectiveness of propulsion systems for Mars landers and Mars interplanetary spacecraft. Access to megawatt power levels (nuclear power coupled to high-storage inductive or capacitive devices) on a manned Mars interplanetary spacecraft may make feasible electromagnetic braking and lift modulation techniques which were previously impractical. Using pulsed microwave and magnetic field technology, potential plasmadynamic braking and hydromagnetic lift modulation techniques have been identified. Entry corridor modulation to reduce loads and heating, to reduce vertical descent rates, and to expand horizontal and lateral landing ranges are possible benefits. In-depth studies are needed to identify specific design concepts for feasibility assessments. Standing wave/plasma sheath interaction techniques appear to be promising. The techniques may require some tailoring of spacecraft external structures and materials. In addition, rapid response guidance and control systems may require the use of structurally embedded sensors coupled to expert systems or to artificial intelligence systems.

  10. Sistem Pendingin Paksa Anti Panas Lebih (Over Heating pada Rem Cakram (Disk Brake Kendaraan

    Directory of Open Access Journals (Sweden)

    Joni Dewanto

    2010-01-01

    Full Text Available Until now, the vehicle brakes are not usually equipped with a special cooling system, so that the release of heat into the air occurs naturally. When used continuously, the brakes can suffer damage as a result of the occurrence of over-heating. This condition is potentially causing a fatal accident. Physically, the over-heating often occurs in type disc brake, because the heat transfer surface is less proportionately, especially for high braking loads. This research aims to develop a brake disc with an active cooling system to prevent overheating. The system is applied to a simulated model of disc brakes empirically. The test was conducted at several levels of constant disc speed and breaking force. The results of this research indicate that at various braking load, the development of disc brakes with an active cooling system in the form of water vapor that is sprayed, can control the brake temperature rise and prevent over-heating.

  11. Dynamic Research on Full Power Hydraulic Wet Braking System of 300 t Mining Truck%300t矿用自卸车全液压湿式制动系统研究

    Institute of Scientific and Technical Information of China (English)

    胡江平; 杨务滋; 彭国普; 罗春雷

    2011-01-01

    This paper presents a new set of full power hydraulic wet braking system, which has multi-stage braking function and better energy-saving effect, and uses a particular oil circuit for cooling. Dynamic research has been done by its AMESim model establishment and simulation. Results indicate that the dynamic response time of running brake and loading brake is respectively about 0. 03s and 0.035s, and time of emergency brake under the normal braking pressure is approximately 0.03s, and the capacity of braking accumulator can meet running brake at least five times. A conclusion is drawn that both dynamic characteristics of the multi-stage brake system and accumulator parameters meet brake reliability requirements of mining truck, which is very valuable for the development and optimization of a new type of full power hydraulic wet braking system.%提出了一套新型的全液压湿式制动系统,该系统具有多级制动功能,节能效果良好,采用独特的油路冷却湿式制动器.在建立该系统的AMESim仿真模型的基础上,对其进行了动态性能研究,研究结果表明:行驶制动与制动锁定的动态响应时间分别约为0.03 s、0.035 s;在正常制动压力下,紧急制动的动态响应时间也约为0.03s;制动蓄能器的容量至少能够满足5次行驶制动.因此该多级制动系统的动态性能与蓄能器的参数均能满足自卸车制动可靠性的设计要求,为开发新型全液压湿式制动系统和优化其性能参数提供了重要依据.

  12. Catecholamines, cardiac natriuretic peptides and chromogranin A: evolution and physiopathology of a 'whip-brake' system of the endocrine heart.

    Science.gov (United States)

    Tota, Bruno; Cerra, Maria Carmela; Gattuso, Alfonsina

    2010-09-15

    In the past 50 years, extensive evidence has shown the ability of vertebrate cardiac non-neuronal cells to synthesize and release catecholamines (CA). This formed the mindset behind the search for the intrinsic endocrine heart properties, culminating in 1981 with the discovery of the natriuretic peptides (NP). CA and NP, co-existing in the endocrine secretion granules and acting as major cardiovascular regulators in health and disease, have become of great biomedical relevance for their potent diagnostic and therapeutic use. The concept of the endocrine heart was later enriched by the identification of a growing number of cardiac hormonal substances involved in organ modulation under normal and stress-induced conditions. Recently, chromogranin A (CgA), a major constituent of the secretory granules, and its derived cardio-suppressive and antiadrenergic peptides, vasostatin-1 and catestatin, were shown as new players in this framework, functioning as cardiac counter-regulators in 'zero steady-state error' homeostasis, particularly under intense excitatory stimuli, e.g. CA-induced myocardial stress. Here, we present evidence for the hypothesis that is gaining support, particularly among human cardiologists. The actions of CA, NP and CgA, we argue, may be viewed as a hallmark of the cardiac capacity to organize 'whip-brake' connection-integration processes in spatio-temporal networks. The involvement of the nitric oxide synthase (NOS)/nitric oxide (NO) system in this configuration is discussed. The use of fish and amphibian paradigms will illustrate the ways that incipient endocrine-humoral agents have evolved as components of cardiac molecular loops and important intermediates during evolutionary transitions, or in a distinct phylogenetic lineage, or under stress challenges. This may help to grasp the old evolutionary roots of these intracardiac endocrine/paracrine networks and how they have evolved from relatively less complicated designs. The latter can also be used

  13. 76 FR 53532 - Jaguar Land Rover North America, LLC, on Behalf of Jaguar Cars Limited, Receipt of Petition for...

    Science.gov (United States)

    2011-08-26

    ... is that the telltales used for Brake Warning, Park Brake Warning and Antilock Braking System (ABS... brake system (ABS) malfunction is detected, the ISO ABS ] symbol illuminates display a message in the..., (65 FR 19477-78). The petition, supporting materials, and all comments received before the close...

  14. 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.)

  15. 自行车碟刹制动距离测试系统的设计与实现%Design and implementation of bicycle disc braking distance test system

    Institute of Scientific and Technical Information of China (English)

    陈梦群; 杨成忠

    2012-01-01

    随着碟刹的使用越来越普及,刹车的可靠性测试显得尤为重要,而国内市场上尚没有针对碟刹的测试系统.针对这一问题,设计了一套自行车碟刹制动距离测试系统.首先建立了自行车的刹车模拟装置,然后在模拟装置上安装了拉力传感器和速度传感器对其进行实时监测,传感器信号由数据采集卡采集并上传至上位机,上位机软件分析数据后下发命令控制模拟装置的刹车过程,并实时显示拉力值、速度值和制动距离等.通过多次制动距离测试,求平均值,确定了碟刹的制动距离,最后进行了试验验证.研究结果表明,该测试系统能够较准确地测量出自行车的制动距离,并且性能稳定,简单易操作,实用性强,具有良好的实际应用价值.%As the bicycle disc brake is getting more and more popular,the reliability testing is very important. But in the domestic market, there is no test system for the disc brake. Aiming at this problem,a system was designed to test the braking distance of the bicycle disc brake. The bicycle simulator was firstly created to simulate bicycle braking. Then a tension sensor and a speed sensor were installed on the braking simulator. The tension sensor was used to indirectly measure the power of gripping on the handlebar when the bicycle simulator was braking. The speed sensor was used to measure the speed of the inertial disc throughout the braking process. The signals of the two sensors were collected by the data acquisition card. The data of the sensors from the data acquisition card was gotten and analyzed, the commands were sent to control of the braking process, the data was real-time displayed,including tension value, velocity,the braking distance and so on. The braking distance of a bicycle disc brake was determined by the average of multiple test results. Finally the verification experiment was done in a factory producing Bicycle disc brakes. The results indicate that the

  16. Low-impact friction materials for brake pads

    OpenAIRE

    Bonfanti, Andrea

    2016-01-01

    State-of-the-art friction materials for applications in disc brake systems are constituted by composite materials, specifically formulated to ensure proper friction and wear performances, under the sliding contact conditions of braking events. The bases of typical friction compound formulations usually include 10 to 30 different components bonded with a polymeric binder cross-linked in situ. Main requests to be fulfilled during braking are an adequate friction efficiency and enough mechanical...

  17. Regenerative Braking Algorithm for an ISG HEV Based on Regenerative Torque Optimization

    Institute of Scientific and Technical Information of China (English)

    XIAO Wen-yong; WANG Feng; ZHUO Bin

    2008-01-01

    A novel regenerative braking algorithm based on regenerative torque optimization with emulate engine compression braking (EECB) was proposed to make effective and maximum use of brake energy in order to improve fuel economy. The actual brake oil pressure of driving wheel which is reduced by the amount of the regenerative braking force is supplied from the electronic hydraulic brake system. Regenerative torque optimization maximizes the actual regenerative power recuperation by energy storage component, and EECB is a useful extended type of regenerative braking. The simulation results show that actual regenerative power recuperation for the novel regenerative braking algorithm is more than using conventional one, and life-span of brake disks is prolonged for the novel algorithm.

  18. 重型内燃牵引车双回路制动系统的设计和研究%Design and Research of Two-Circuit Braking System in Heavy Motor Tractor

    Institute of Scientific and Technical Information of China (English)

    张瑜

    2015-01-01

    介绍了双回路气制动系统在内燃牵引车如何有效地应用。该系统通过使用液压元件和气压元件,保证当一个制动回路失灵后,第二个制动回路能正常工作。同时在两套管路中设置比例阀,分别调节前后制动器分泵压力,使每个车轮有合适的制动力,充分利用整车附着力,使得工程车辆既能达到最大的制动力,保证整车安全可靠性。气源通过气制动控制系统与制动泵相连接,能够实现牵引的挂车制动的远程集中控制。同时利用重型卡车成熟的气制动控制元件和叉车成熟的液压制动执行元件,满足了港口牵引车的制动安全性、结构的紧凑性,又能够实现牵引的挂车制动的远程集中控制,具有很好的拓展性。%This article introduces the effective implication of two-circuit braking system in internal combustion tractor. This system uses hydraulic components and pneumatic components to make sure the second circuit braking system is in working or-der when the first fails. Meanwhile, proportional valves are installed in both circuits to adjust the pressure of front and rear brakes. Therefore, each wheel has appropriate brake force. By taking advantages of friction, the vehicle can achieve the maxi-mum braking force which ensures safety and reliability. Air source is connected with the brake pump through air braking con-trol system, thus to realize the remote centralized control of the braking of trailer. Moreover, it applies mature air brake com-ponents of heavy truck and mature hydraulic components of forklift truck. So that it satisfies braking safety and structural com-pactness, which has favorable expansibility.

  19. Effects of damping on the speed of increase and amplitude of limit cycle for an aircraft braking system subjected to mode-coupling instability

    OpenAIRE

    Chevillot, Fabrice; Sinou, Jean-Jacques; Hardouin, Nicolas; Jezequel, Louis

    2010-01-01

    International audience A nonlinear model of an aircraft braking system is presented and used to investigate the effects of damping on the stability in Chevillot et al. (Arch Appl Mech 78(12):949-963, 2008). It has been shown that the addition of damping into the equations of motion does not lead systematically to the stabilization of the system. In the case of a mode-coupling instability, there is indeed an optimal ratio between the modal damping coefficients of the two modes in coalescenc...

  20. The destabilization paradox applied to friction-induced vibrations in an aircraft braking system

    OpenAIRE

    Chevillot, Fabrice; Sinou, Jean-Jacques; Mazet, Guy-Bernard; Hardouin, Nicolas; Jezequel, Louis

    2008-01-01

    International audience Mechanisms of friction are known as an important source of vibrations in a large variety of engineering systems, where the emergence of oscillations is noisy and can cause severe damage to the system. The reduction or elimination of these vibrations is then an industrial issue that requires the attention of engineers and researchers together. Friction-induced vibrations have been the matter of several investigations, considering experimental, analytical, and numerica...

  1. Towards A Good ABS Design for More Reliable Vehicles on the Roads

    Directory of Open Access Journals (Sweden)

    Afifa Ghenai

    2013-07-01

    Full Text Available Nowadays, better driving also means betterbraking. To this end, vehicle designersmust find allfailuresduring the design phase of antilock braking systems which play animportant roleinautomobilessafety.However, mechatronic systems are so complex and failures can be badly identified. So it is necessary topropose a design approach of an antilock braking system which will be able to avoid wheels locking duringbraking and maintain vehicle stability. This paper describes this approach, in which we model thefunctional and the dysfunctional behavior of an antilock braking system using stopwatch Petri nets

  2. Frictional couplings of wheel with a rail in a brake control system of rail vehicles

    OpenAIRE

    Baier, A; A. Niedworok

    2011-01-01

    Purpose: Discussion on use of frictional coupling of wheel with a rail for detection of surface condition of track ways in coal mine undergrounds is the paper objective.Design/methodology/approach: The method for detection of surface condition of track ways is based on using of dedicated converter installed on the locomotive chassis with active part in a form of “tracking wheel” that moves on the rail surface together with the locomotive. The converter is equipped with a system for torque loa...

  3. Impact of Inertia Acting on Braking System with Varying Load and Fixed Torque%转动惯量对变载恒转矩制动系统性能的影响

    Institute of Scientific and Technical Information of China (English)

    陈正

    2014-01-01

    以扶梯为例,根据动力学的基本原理,推导了扶梯制动力矩、制停距离与负载变化、系统运动部件固有总质量之间的关系公式,描述了扶梯主机高速轴转动惯量对扶梯制动能量、制停距离、制动力矩的调节作用,为变载恒转矩制动系统性能的优化,特别是如何满足变载乘客运输系统的制动部件的规范要求和配置特点,提供参考性意见。%As a case study about escalators, according to the principle of dynamics, derived the formula about the relation of escalator brake torque, stopping distance, the varying passenger load, and the total inherent mass of moving components, described the impact regulation of rotational moment of inertia at high-speed shaft which how to acting on the escalator braking energy, stop distance and braking torque. Put forward reference comment about constant torque braking system performance optimization with varying load, especially how to comply with code requirement of escalator and how to configure braking system features for passenger transport system with varying load.

  4. ACTIVE FRONT STEERING DURING BRAKING PROCESS

    Institute of Scientific and Technical Information of China (English)

    CHEN Deling; CHEN Li; YIN Chengliang; ZHANG Yong

    2008-01-01

    An active front steering (AFS) intervention control during braking for vehicle stability is presented. Based on the investigation of AFS mechanism, a simplified model of steering system is established and integrated with vehicle model. Then the AFS control on vehicle handling dynamics during braking is designed. Due to the difficulties associated with the sideslip angle measurement of vehicle, a state observer is designed to provide real time estimation. Thereafter, the controller with the feedback of both sideslip and yaw angle is implemented. To evaluate the system control, the proposed AFS controlled vehicle has been tested in the Hardware-in-the-loop-simulation (HILS) system and compared with that of conventional vehicle. Results show that AFS can improve vehicle lateral stability effectively without reducing the braking performance.

  5. 飞机数字电传防滑刹车系统污染控制方法研究%Study on the Pollution Control Method for Aircraft Digital Telex Antiskid Brake System

    Institute of Scientific and Technical Information of China (English)

    刘忠平; 亢敏; 韩亚国; 赵文庆

    2015-01-01

    The work principles, using requirements and pollution control requirements for high precision electro⁃hydraulic servo valve were discussed from a view of solving oil pollution problem synthetically in braking control system. The pollution control methods and ways were proposed. Through controlling pollution in the aspects of design, utility and maintenance of the braking control system, braking wheels and hydraulic tubes, holding brake pressure in air and braking failures caused by hydraulic oil pollution could be effec⁃tively avoided.%从刹车系统污染综合治理角度出发,论述了飞机刹车控制系统中高精度电液伺服阀的工作原理、选用要求及污染度控制要求,提出了飞机刹车系统油液污染控制的方法和途径。通过在刹车系统、刹车机轮、刹车管路的设计、使用、维护等方面进行污染控制,能够有效避免飞机刹车系统在使用中由于污染问题导致着陆过程中出现空中带压、刹车失效现象。

  6. LQG Control of Acceleration/Braking System Based on Wheelbase Preview%预瞄信息空气悬架汽车在加速/制动工况下的LQG控制

    Institute of Scientific and Technical Information of China (English)

    潘公宇; 黄宇

    2012-01-01

    A mathematic model of one second vehicle about acceleration/braking system based on air suspension is established. By applying wheelbase preview control to forecast the road surface roughness at the front wheel, the optimal controller based on wheelbase preview control theory is designed. Then the simulation is implemented in the MATLAB/Simulink environment. The simulation results show that the performance of the active air suspension acceleration/braking system with a LQG controller based on wheelbase preview can effectively suppress vehicle vibration compared with the passive air suspension acceleration/braking system; and compared with the optimal air suspension acceleration/braking system, the active air suspension acceleration/braking system does well in improving the ride comfort of acceleration/braking system.%建立了基于空气悬架的1/2车辆加速/制动系统模型,通过轴距预瞄在后轮处提前预测路面不平度;设计了基于轴距预瞄控制算法的加速/制动最优控制器;进行了白噪声仿真分析.仿真结果表明:与被动空气悬架加速/制动系统相比,基于轴距预瞄控制的主动空气悬架加速/制动系统能有效降低车辆振动.与最优控制空气悬架加速/制动系统相比,质心加速度和后轮对应处的车身加速度、悬架动行程、轮胎动载均有显著减小,较好的改善了车辆在加速/制动时的平顺性和操纵稳定性.

  7. Optical classification for quality and defect analysis of train brakes

    Science.gov (United States)

    Glock, Stefan; Hausmann, Stefan; Gerke, Sebastian; Warok, Alexander; Spiess, Peter; Witte, Stefan; Lohweg, Volker

    2009-06-01

    In this paper we present an optical measurement system approach for quality analysis of brakes which are used in high-speed trains. The brakes consist of the so called brake discs and pads. In a deceleration process the discs will be heated up to 500°C. The quality measure is based on the fact that the heated brake discs should not generate hot spots inside the brake material. Instead, the brake disc should be heated homogeneously by the deceleration. Therefore, it makes sense to analyze the number of hot spots and their relative gradients to create a quality measure for train brakes. In this contribution we present a new approach for a quality measurement system which is based on an image analysis and classification of infra-red based heat images. Brake images which are represented in pseudo-color are first transformed in a linear grayscale space by a hue-saturation-intensity (HSI) space. This transform is necessary for the following gradient analysis which is based on gray scale gradient filters. Furthermore, different features based on Haralick's measures are generated from the gray scale and gradient images. A following Fuzzy-Pattern-Classifier is used for the classification of good and bad brakes. It has to be pointed out that the classifier returns a score value for each brake which is between 0 and 100% good quality. This fact guarantees that not only good and bad bakes can be distinguished, but also their quality can be labeled. The results show that all critical thermal patterns of train brakes can be sensed and verified.

  8. 摩擦式制动器与非接触轮边缓速器集成系统仿真分析%Simulation of Integrated System of Frictional Brake and Contactless Wheel Retarder

    Institute of Scientific and Technical Information of China (English)

    何仁; 刘存香

    2011-01-01

    为了有效提高轿车制动效率,建立了摩擦式制动器与非接触轮边缓速器集成系统控制模型,获得了缓速器制动力矩和集成系统总制动力矩随车轮转动角速度的变化关系;提出了通过脉冲宽度调制调节缓速器线圈通电电流从而改变集成系统总制动力矩的方法.利用建立的系统控制模型和控制策略对汽车制动性能进行仿真.仿真和实例分析表明,与传统的制动系统相比,摩擦式制动器与非接触轮边缓速器集成系统使制动时间缩短3.7s,制动距离减少76.8 m.%In order to improve the vehicle brake efficiency, the controlling model of the integrated system including frictional brake and contactless wheel retarder is built, and the relationship of the retarder braking torque and whole torque with the wheel rotational angular velocity is obtained. According to the pulse width modulation regulated theory, the method for regulating the voltage of the retarder coil is presented to change the whole system torque. The vehicle brake performance is simulated according to the system controlling model and the control stragety. The simulation results show that, compared with the traditional system, the braking time of the integrated system reduces by 3.7 s.and the braking distance reduces by 76. 88 m.

  9. Study on the Optimum Service Braking System for Low-speed Goods Vehicle%低速货车配备行车制动系统的研究

    Institute of Scientific and Technical Information of China (English)

    马恩; 杨博竣

    2016-01-01

    Current condition of service braking system for low-speed goods vehicle in China are discussed. Service brake safety properties of low-speed goods vehicle are affected directly by service brake system. To ex-plore the optimum designs of service braking system for low-speed goods vehicle, tests were carried out in ac-cordance with GB7258-2012 safety specifications for power-driven vehicles operating on roads. Research and practice in a long period proves the optimum designs are service manual hydraulic braking system for load less than one ton low-speed goods vehicle, but are service power pneumatic braking system for load more than one ton low-speed goods vehicle.%论述了我国低速货车配备行车制动系统的现状,低速货车行车制动系统直接影响其行车安全,试验按照强制性国家标准GB7258-2012《机动车运行安全技术条件》进行,经过研究人员长期研究和实践证明,得到最佳方案是:载重量小于1t的低速货车配备行车人力液压制动系统;载重量大于1t的低速货车配备行车动力气压制动系统。

  10. 直流无刷电机再生制动系统试验台的设计与验证%Design and Verification of Brushless DC Motor Regenerative Braking System Test Bench

    Institute of Scientific and Technical Information of China (English)

    隋妮; 王广萍; 李仲兴; 张德望; 顾剑波

    2011-01-01

    基于再生制动理论,以电动汽车用轮毂电机为主体,搭建了直流无刷电机再生制动试验台.以回收能量最大化为目标,提出了相应的再生制动控制策略.结合电机的输出特性和工作原理,利用SIMULINK软件建立了再生制动系统模型.通过模型仿真和试验台试验结果的对比分析,验证了再生制动试验台设计方案的可行性和控制策略的合理性.%Basod on theory of regenerative braking, with electric vehicle hub motor as subject, a brushless DC motor regenerative braking test bench is built. To maximize energy recovery, regenerative braking control strategy is proposed in the paper. In accordance with output characteristic and working principle of motor,regenerative braking system is established with software SIMULINK.By modeling simulation and contrastive analysis of the test result, feasibility of design program of regenerative braking test bench and rationality of control strategy are validated.

  11. 新型高性能提升机智能电液制动系统的研究%Intelligent Electro-Hydraulic Braking System of New High Performance Hoister

    Institute of Scientific and Technical Information of China (English)

    史世杰; 张根现; 马星河

    2011-01-01

    The high performance intelligent electro-hydraulic hoist braking system further improves the safety of large mine hoist braking performance.Using modern electro-hydraulic control theory,the system is made up of high performance disc brakes,brake on-line monitor system,constant deceleration,hydraulic station,constant deceleration cabinet and the speed measurement equipment.When emergency braking,the system can always brake as the pre-set deceleration speed,not change along with load or working conditionIt not only improves the safety and reliability of mine hoist,but also improves production efficiency.%为进一步提高大型矿井提升机安全制动性能,运用现代电液控制理论,设计了由高性能盘形制动器、制动器在线监控系统、恒减速度液压站、恒减速度电控柜,以及测速装置组成的智能电液制动系统。该系统在紧急制动时,能使制动减速不随负载、工况变化而变化,始终按预先设定的减速度值进行制动,既可提高矿井提升机的安全可靠性,又提高生产效率。

  12. Study on Validation Method of the Leak and Failure of Passenger Vehicle’s Brake Pipes System%乘用车制动管路系统泄露失效验证方法研究

    Institute of Scientific and Technical Information of China (English)

    刘成华; 武文超; 陈伟波; 施杰

    2013-01-01

    In the modern passenger car, the brake pipe system connects the booster & master cylinder and brake control modulator. During the vehicle’s running, the either end of brake pipe will vibrate at different frequency and different amplitude. Therefore, if the brake pipe system is not legitimately designed, the nonsynchronous vibration will lead to the rupture of brake pipe. So the design of brake pipes system and how to validate if it can meet the demand of vehicle life cycle are very important. This paper analyzes the vibration leakage issue of vibration leakage issue, and gives the validation method. The method also has some reference for the validation of other vehicle vibration parts.%现代乘用车连接助力器主缸总成与制动防抱死模块的制动管路系统两端的振动强度不同,如果该管路系统设计不合理则极易产生泄露。因此该制动管路系统的设计及如何验证其能够满足整车生命周期显得尤为重要。本文对乘用车驻车制动管路系统断裂进行了初步研究,并给出了其验证方法,对汽车其他零件或结构振动失效验证也具有一定的参考意义。

  13. Heat distribution in disc brake

    Science.gov (United States)

    Klimenda, Frantisek; Soukup, Josef; Kampo, Jan

    2016-06-01

    This article is deals by the thermal analysis of the disc brake with floating caliper. The issue is solved by numerically. The half 2D model is used for solution in program ADINA 8.8. Two brake discs without the ventilation are solved. One disc is made from cast iron and the second is made from stainless steel. Both materials are an isotropic. By acting the pressure force on the brake pads will be pressing the pads to the brake disc. Speed will be reduced (slowing down). On the contact surface generates the heat, which the disc and pads heats. In the next part of article is comparison the maximum temperature at the time of braking. The temperatures of both materials for brake disc (gray cast iron, stainless steel) are compares. The heat flux during braking for the both materials is shown.

  14. 120阀内孔径对制动系统性能的影响%The effect of the 120 valve apeture to the brake system performance

    Institute of Scientific and Technical Information of China (English)

    赵阳; 魏伟

    2012-01-01

    使用基于气体流动理论的列车制动系统数值仿真方法定量分析了120阀的紧急阀Ⅲ孔径、局减阀上的局减孔孔径、加缓风缸向列车管充气孔孔径对单编万吨列车制动、缓解特性的影响.仿真结果表明:紧急阀Ⅲ孔径对列车的紧急制动特性有明显的影响.该孔径在2.3 ~2.7 mm范围内能够保证在常用制动时不发生紧急作用,同时紧急作用也能正常发生,并且该孔径越大,其制动波速越慢,在紧急制动时,该孔径由2.35 mm增大到2.65 mm,其制动波速由283.2 m/s降低到244.2 m/s,降低了14.2%;局减阀上局减孔孔径对常用制动时的制动波速有明显的影响,孔径越大,其常用制动的制动波速越快,在减压100 kPa时,孔径为1.5 mm时比0.5 mm时制动波速增大了77.4%;加缓风缸向列车管充气孔的大小对缓解波速有明显的影响,该孔径越大,缓解波速越快,在减压100 kPa之后缓解的过程中,随着该孔径由0.5 mm增大到1.5mm,缓解波速增大了53.1%,小减压量制动后缓解时,该孔径大小对缓解波速影响较小.该结论为新阀的设计提供了参考.%The influence of emergency valve III hole, the local reduction valve hole, and the acceleration release cylinder hole to the train pipe on brake system characteristics was simulated with the train braking system numeri cal simulation method which based on air flow theory. The results show that the emergency valve III hole's size has obvious influence to the emergency brake characteristic of train; the hole size in the range of (2. 3 ~ 2.7) mm ensure the emergency application valve does not work in normal brake; the emergency valve III hole is big ger, its brake propagation speed is slower, the hole increases from 2. 35 mm to 2. 65 mm and its brake propagation speed changed from 283. 6 m/s to 244. 2 m/s, reduced by 14. 2% when it works; the size of the local re duction holes has influence to the service application brake

  15. 刹车系统的摩擦自激振动和控制%FRICTION-INDUCED SELF-EXCITED VIBRATION AND CONTROL OF A BRAKE SYSTEM

    Institute of Scientific and Technical Information of China (English)

    贾尚帅; 丁千

    2012-01-01

    The non-linear dynamics and control of friction-induced vibration in a brake system are investigated. Adopting the LuGre friction model, the dynamical equations of a 2-DOF disc brake system are derived by considering the friction force between the disc and the pad. The critical speed of Hopf bifurcation of the equilibrium is obtained through stability analysis. The design method based on differential geometry and linear quadratic optimal control for SISO nonlinear system controller is used to reduce the chatter phenomena during deceleration-type braking by postponing the critical speed of Hopf bifurcation. At last, the influences of the controller and the system parameters are analyzed. The simulation result shows that the method based on differential geometry and linear quadratic optimal is effective to control the self-excited vibration.%研究刹车系统的摩擦自激振动和控制问题。采用LuGre模型计算摩擦力,建立了两自由度盘式刹车系统的动力学模型。通过平衡点的稳定性分析,给出Hopf分岔失稳的临界速度。应用基于微分几何法和线性二次型最优控制相结合的方法,设计单输入单输出的非线性系统控制器,以便通过推迟系统的分岔临界速度,减少减速型刹车过程中的摩擦颤振,避免刹车啸叫。最后分析了控制器和系统参数对控制效果的影响。仿真表明,该控制器能有效的抑制刹车系统中的摩擦自激振动。

  16. Automobile electronic parking brake system (EPB) and pplication development%汽车电子驻车制动系统(EPB)的研发与应用

    Institute of Scientific and Technical Information of China (English)

    周娟英

    2014-01-01

    With thedevelopment of automobile electronic technology, auto control more and more components from the traditional mechanical control mode is gradually transformed into electronic control mode.For example,previously only in some luxury cars can see electronic brake system,is now being applied to medium and small cars.Electronic parking brake system (EPB)and the application of the further impetus to the integration of automotive electronic control system,not only reduces the complexity of the body structure, the optimization of the system of space,but also can reduce the cost,improve the reliability of the system.%随着汽车电子技术的不断进步,越来越多的汽车控制组件从传统的机械控制方式逐渐转变为电子控制方式。比如以前只能在一些高级豪华车上才能看得到的电子刹车系统,如今也逐渐被应用到中小型汽车上。电子驻车制动系统(EPB)的出现和应用更进一步地推动了汽车电子控制系统的集成,不仅降低了车身结构的复杂性,优化了系统的空间,还可以降低成本,提高系统的可靠性。

  17. Design of a Disk Brake for Belt Conveyor Hydraulic Control System Design%一种带式输送机盘式制动器液压控制系统的设计

    Institute of Scientific and Technical Information of China (English)

    曹秀洪

    2013-01-01

      文中基于盘式制动器设计了一个液压控制系统,该系统的设计是针对带式运输机在运输过程中的控制问题设计的,所以它的稳定性能和反映能力都占有绝对的优势。文中简单的介绍了液压系统遇到松闸过程、保压过程、正常停车、超速制动、紧急制动和系统突然断电等情况时的运行状况。%  Based on the design of disk brake on a hydraulic control system, the system design is for the belt conveyor in the transportation process control design, so its stability properties and screening ability has the absolute advantage. This paper introduces the hydraulic system of brake loosing process, encountered pressure, normal parking, overspeed braking, emergency braking and system failure, when the running state airport.

  18. Research of vehicle steering and braking system based on fuzzy decoupling control%基于模糊解耦控制的车辆转向制动系统研究

    Institute of Scientific and Technical Information of China (English)

    陈燕芹; 李晓旭; 段婷婷

    2014-01-01

    车辆转向系统和制动系统之间存在着很强的速度耦合关系,造成两个系统之间的性能相互影响,使得车辆在转向制动这一工况成了汽车最危险的工况之一。本文结合实际车辆参数建立转向系统的二自由度模型和制动系统的单车轮模型,针对车辆转向制动工况设计了模糊解耦控制器,实现了车辆的转向与制动同时控制。经验证含有模糊解耦控制的车辆转向制动系统具有很好的动态控制效果,并且有很强的鲁棒性和自适应性。%The strong velocity coupling relationships between the automotive steering and braking systems and the systems' performance of mutual influence make the vehicle steering and braking working condition become one of the most dangerous conditions. This paper established a two degree of freedom model of automobile steering systems and a single wheel braking system model based on the actual parameters of vehicle, and designed the fuzzy decoupling controller for controlling simultaneously vehicle steering and braking systems. As a result, the fuzzy decoupling controller of vehicle steering and braking systems has good dynamic control effect, and has strong robustness and adaptability.

  19. Experiments with airplane brakes

    Science.gov (United States)

    Michael, Franz

    1931-01-01

    This report begins by examining the forces on the brake shoes. For the determination of the load distribution over the shoes it was assumed that the brake linings follow Hooke's law, are neatly fitted and bedded in by wear. The assumption of Hooke's law, that is, the proportionality between compression of the lining and the absorption of force, is fulfilled to a certain extent for the loading, as becomes apparent from the load tests described further on. But there is a material discrepancy at unloading. From the load distribution we merely defined the position of the normal force resultant, while for the rest, the effect of the distribution was disregarded in the comparison of the different shoe dispositions.

  20. 基于AMESim的100%低地板轻轨车制动系统仿真研究%Simulation Research of 100%Low Floor Light Rail Vehicle Braking System Based on AMESim

    Institute of Scientific and Technical Information of China (English)

    郑志超; 倪文波

    2016-01-01

    100%低地板轻轨车是目前城市轨道交通系统中发展十分迅速的交通形式。由于它采用低地板结构,导致车下空间狭小,需采用体积较小的液压制动系统。针对应用最普遍的2M1T模块的100%低地板轻轨车制动系统进行研究,在提出制动系统方案的基础上运用AMESim软件完成制动系统建模,选择超员载荷工况下的最大常用制动和紧急制动两种制动工况进行仿真分析,仿真结果验证了该方案的正确性,可对100%低地板轻轨车制动系统的研究与开发提供参考。%100%low floor light rail vehicle is a transportation form which is developed very rapidly in urban rail transit systems. Due to its structure with low floor, the space underneath is narrow, so 100%low floor light rail vehicle has to use hydraulic braking system, which has smaller volume.The research on the widely used 100%low floor light rail vehicle braking system which was consis-ted of 2M1T was carried out.On the basis, the scheme of braking system was proposed, the braking system was modeled by using AMESim software.Then full service braking and emergency braking in overcrowding load condition were chosen to be simulated and an-alyzed.The correctness of the scheme was verified by simulation results.The simulation results can provide reference for research and development of 100%low floor light rail vehicle braking system.

  1. 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.

  2. 地铁列车制动系统的中继阀性能仿真%Simulation of Relay-valve of Metro Braking System Performance

    Institute of Scientific and Technical Information of China (English)

    伍智敏; 任利惠; 裴玉春; 吴萌岭

    2011-01-01

    A simulation model of relay - valve is built by using AMEsim software according to the structure and mechanism of relay - valve, in which the flow rate relating to the overlap of intake port and exhaust port is controlled by rod's placement. In order to simulate the performance of relay valve, a simulation model of the metro pneumatic braking system is built, which includes the brake cylinders, pipes, electro-magnetic valves and Bang-Bang controller. The influence of relay-valve's flow rate on the metro braking performance is given by comparing the pressure rise time in different maximum under-lap of the intake port. The reasonable maximum intake port under-lap of relay -valve is 1.5 mm and the reasonable value range of the pore size of orifice in relay valve is about 2 to 4 mm.%根据地铁列车制动系统的中继阀结构和作用原理,使用AMEsim软件建立了中继阀的仿真模型,较真实地模拟了中继阀的实际物理结构.它由两个双作用气缸及两个截止阀组成,通过连杆开关进、排气口,达到控制其流量的目的.在此基础上,使用AMEsim软件建立了整个地铁列车空气制动系统的仿真模型,仿真分析了阶段制动和紧急制动时制动缸的压力上升时间和制动缸、副风缸的温度变化.通过分析中继阀流量对制动缸压力上升时间的影响,得出中继阀进气口的设计最大开度1.5mm是合理的,节流孔孔径的合理取值范围为2~4 mm.

  3. 轻型电动汽车新型制动能量回收系统的研究%Research of a new brake energy recovery system of the light electric car

    Institute of Scientific and Technical Information of China (English)

    王新彦; 赵培; 桂天; 张胜文; 李忠国

    2013-01-01

      针对目前电动汽车制动能量回收效率偏低的问题,采用制动能量回收与利用并举的方法,以长安奔奔mini为样车,设计了一种新型制动能量回收系统,使再生制动时一部分电流为车载电池充电,一部分电流经整流转换后提供给开启的车用电器;建立该系统的动力学模型,得到了再生制动时功率Pe 与电机转速n的对应关系;并搭建了该新型制动能量回收系统的模拟实验平台,采用并行制动控制策略,测得了再生制动时回收利用的功率及其电机转速的时间历程曲线,通过计算得出了回收利用的制动能量及其效率.实验结果表明:当电机(2830 r· min-1)开始制动时,新型制动能量回收系统的效率提高了5.01%,验证了该设计方案的可行性与有效性.%In order to solve the problem of the low efficiency of braking energy recovery systems , a method of re-covering and utilizing braking energy was used to design a new braking energy recovery system based on the Chang'an Benben mini car .One part of the electric current was used for the recharge of the battery , while the other part of the current supplied the electrical devices of the car after current rectifier .The dynamic model of the new braking energy recovery system was established , the corresponding relations of the regenerative braking pow-er ( Pe ) and the motor speed ( n) with time were obtained and the simulative experiment device of the new bra-king energy recovery system was developed .The power and corresponding rotating speed of the electric engine with time were measured by the experiment with parallel control strategy , and then the energy and the efficiency of regenerative braking were calculated .The experimental results show that when the motor begins to brake from the speed of 2 830 r· min -1 , the efficiency of the new braking energy recovery system is increased by 5.01%compared with that of

  4. 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

  5. 49 CFR 229.57 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Brake System § 229.57... to the wheel to prevent localized thermal stress in the edge of the rim or the flange....

  6. Experimental investigations for uncertainty quantification in brake squeal analysis

    Science.gov (United States)

    Renault, A.; Massa, F.; Lallemand, B.; Tison, T.

    2016-04-01

    The aim of this paper is to improve the correlation between the experimental and the numerical prediction of unstable frequencies for automotive brake systems considering uncertainty. First, an experimental quantification of uncertainty and a discussion analysing the contributions of uncertainty to a numerical squeal simulation are proposed. Frequency and transient simulations are performed considering nominal values of model parameters, determined experimentally. The obtained results are compared with those derived from experimental tests to highlight the limitation of deterministic simulations. The effects of the different kinds of uncertainty detected in working conditions of brake system, the pad boundary condition, the brake system material properties and the pad surface topography are discussed by defining different unstable mode classes. Finally, a correlation between experimental and numerical results considering uncertainty is successfully proposed for an industrial brake system. Results from the different comparisons reveal also a major influence of the pad topography and consequently the contact distribution.

  7. Clutches and brakes design and selection

    CERN Document Server

    Orthwein, William C

    2004-01-01

    FRICTION MATERIALSFriction CodeWearBrake FadeFriction MaterialsNotationReferencesBAND BRAKESDerivation of EquationsApplicationLever-Actuated Band Brake: Backstop DesignExample: Design of a BackstopNotationFormula CollectionReferencesEXTERNALLY AND INTERNALLY PIVOTED SHOE BRAKESPivoted External Drum BrakesPivoted Internal Drum BrakesDesign of Dual-Anchor Twin-Shoe Drum BrakesDual-Anchor Twin-Shoe Drum Brake Design ExamplesDesign of Single-Anchor Twin-Shoe Drum BrakesSingle-Anchor Twin-Shoe Drum Brake Design Exam

  8. 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.

  9. Modelling of friction-induced brake oscillations; Modellbildung reibungsselbsterregter Bremsenschwingungen

    Energy Technology Data Exchange (ETDEWEB)

    Rudolph, M.; Popp, K. [Hannover Univ. (Germany). Inst. fuer Mechanik

    2001-07-01

    Oscillatory mechanisms describing the energy transfer from the brake disk into the mechanical brake system are described and discussed, and an extended model of a real brake is presented. It is a multi-element system which takes account of elastic modes of the brake components. Components with high relevance for the initiation of oscillations are identified on the basis of a sensitivity analysis of the linear model. [German] Es werden Erregungs-Mechanismen (fallende Reibkennlinie, geometrische Instabilitaet, nichtkonservative Lagekraefte) zur Beschreibung des Energieeintrages von der Bremsscheibe in das mechanische System Bremse dargelegt und diskutiert. Darauf aufbauend wird ein erweitertes Prinzipmodell vorgestellt, das eine reale Schwimmsattelbremse beschreibt. Dabei handelt es sich um ein Mehrkoerpersystem, das elastische Moden der Bremsenbauteile beruecksichtigt. Anhand einer Sensitivitaets-Analyse des linearen Modells werden Bauteile mit hoher Relevanz fuer die Schwingungsanregung identifiziert. (orig.)

  10. Thermal Characterisation of Brake Pads

    DEFF Research Database (Denmark)

    Ramousse, Séverine; Høj, Jakob Weiland; Sørensen, O. T.

    2001-01-01

    The chemical-physical decomposition processes that occur in a brake pad heated to 1000degreesC have been studied. This temperature can be reached when a brake pad is applied. Thermogravimetry and differential thermal analysis were used in combination with evolved gas analysis, and image analysis...

  11. Optimization method of frictional braking force distribution for integrated system of electromagnetic and frictional braking of car%轿车电磁与摩擦制动集成系统摩擦制动力分配优化方法

    Institute of Scientific and Technical Information of China (English)

    何仁; 赵强; 胡东海

    2015-01-01

    分析了轿车电磁与摩擦制动集成系统的结构与工作原理,推导了轿车前后轴利用附着系数的计算公式。以 ECE R13制动法规与电磁制动器设计要求为约束条件,以轿车前后轴实际利用附着系数与理想状态制动强度差值的平方和最小为目标函数,以 MATLAB 优化工具箱为计算工具,建立了轿车电磁与摩擦制动集成系统摩擦制动力分配优化方法,计算了不同工况下的摩擦制动力分配最优值。计算结果表明:当制动强度分别为0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.8时,优化前的目标函数值分别为0.03、0.05、0.07、0.07、0.08、0.07、0.06、0.04,优化后的的目标函数值分别为0.00、0.00、0.00、0.00、0.00、0.00、0.01、0.01,优化后,目标函数值明显减小,轿车前后轴利用附着系数曲线更靠近理想曲线,且均在 ECE R13制动法规控制曲线的下方,因此,提出的优化方法满足ECE R13制动法规的要求,轿车制动稳定性得到提高。%The structure and working principle of integrated system of the electromagnetic and frictional braking for car were analyzed.The calculation formula of utilization adhesion coefficient for front and rear axles was derived.The ECE R13 braking regulation and the design requirement of electromagnetic braking were taken as constraint conditions,the minimum square sum of differences between the actual curve of utilization adhesion coefficient and the braking strength of ideal condition for front and rear axles was taken as objective function,MATLAB optimization toolbox was employed,the optimization method of frictional braking force distribution for the integrated system of electromagnetic and frictional braking was established,and the optimal values of frictional braking force distribution under different conditions were calculated. Calculation result indicates when the braking strength is 0

  12. 复合式制动气室性能在线检测系统设计%Disquisition of Performance On-line Detection System for Brake Chamber

    Institute of Scientific and Technical Information of China (English)

    刘宁霞; 罗哉

    2012-01-01

    设计并实现复合式制动气室性能在线检测系统,弥补国内对复合式制动气室性能在线检测研究存在的不足.引入伺服加载机构,突破以往检测中推杆行程限位装置加载速度不可控的局限,实现限位装置的加载速度精确可调;应用高速数据采集卡和计算机控制技术,提高系统的采集速度和测量精度.可对多类型的复合式制动气室驻车制动腔静特性、行车制动腔静特性、开始释放压力等性能进行在线测试和分析.通过试验分析表明检测系统能真实准确的对复合式制动气室的性能进行在线检测,检测周期小于2min/个,其测量精度达到实际应用的要求,并采用R&R法客观的分析检测系统,已达到新设备的验收条件.%The on-line detection system for brake chamber was designed and realized, which made up for the domestic deficiency of on-line detection research for brake chamber. Servo-loading mechanism was introduced in the design of test system to break through the limitation of which previous test can not control the load speed of brake chamber and to achieve load speed precisely and adjustably. Using high-Speed data collection card and computer control technology to improve the sampling speed and the measuring accuracy of the system. It can test as well as analysis the static characteristic of parking brake chamber, static characteristic of service brake chamber and hold-off pressure on-line. Through the test and analysis shows that, the detection system can true accurate the performance of complex braking gas chamber by on-line detection, which the period less than 2 min, the measuring precision has met the practical requirement. Using the R&R method to objectively analysis the detection system, has reached the conditions of the new equipment successfully.

  13. Braking Resistor Scheme for Transient Stability Improvement

    OpenAIRE

    Saeed Abazari

    2007-01-01

    One of the most important problems in power systems design is increasing the damping of the swing amplitude and also to increase the critical time in transient stability. One of the best techniques is to use resistor braking. However, their performance in power systems, duration of their activity and their place of installation are of great importance. In this paper by using of some of devices in power electronics and by precies modeling of the network and optimal controller is designed which...

  14. Design of brake pedal displacement measuring system based on Hall sensor%基于霍尔传感器的制动踏板行程测量系统设计

    Institute of Scientific and Technical Information of China (English)

    刘东辉; 吴初娜

    2012-01-01

    To solve the requirements of collecting the brake pedal displacement data in the driving simulator and locate the brake pedal position accurately,a brake pedal displacement measuring system which consists of two Hall sensors,seven small magnets,one SCM control system was presented,its working principle and realizing method were introduced.The Hall effect principle was used to locate the brake pedal position.The pulse signal was detected and output by Hall sensors,and was sent to the SCM control system after phase reverse and demodulation.The SCM calculated the brake pedal displacement based on the pulse signal.The result proves that the measurement error of the system is less than ±3%,and the measuring performance is stable.It also has the advantages of small dimension and low cost.It can fulfill the requiring of measuring the brake pedal displacement.9 figs,6 refs.%为了解决驾驶模拟器中对制动踏板行程的数据采集需求,使其能精确判断出制动踏板所处的位置,设计了一种由2个霍尔传感器、7个小磁块和1个单片机控制系统组成的制动踏板行程测量系统,并介绍了其原理与实现方法。采用霍尔效应原理来测量制动踏板的行程,通过霍尔传感器感应到磁块后输出脉冲信号,将脉冲信号进行反向和相位解调处理后输入单片机控制系统;单片机控制系统根据脉冲信号计算得到制动踏板行程。结果表明,该测量系统的测量误差小于等于±3%,测量性能稳定,且具有体积小、成本低等优点,可以满足对制动踏板行程进行测量的需要。

  15. Braking Resistor Scheme for Transient Stability Improvement

    Directory of Open Access Journals (Sweden)

    Saeed Abazari

    2007-09-01

    Full Text Available One of the most important problems in power systems design is increasing the damping of the swing amplitude and also to increase the critical time in transient stability. One of the best techniques is to use resistor braking. However, their performance in power systems, duration of their activity and their place of installation are of great importance. In this paper by using of some of devices in power electronics and by precies modeling of the network and optimal controller is designed which leads as to our final objective. In fact resistor braking are effectively attract additive energy which is a result of disturbances and help us to improve the stability of overall system.

  16. 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.

  17. 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

  18. Use of a hydraulic brake as a source of thermal energy for the railway rolling stock

    Directory of Open Access Journals (Sweden)

    V.A.Gabrinets

    2012-12-01

    Full Text Available Introduction: In this paper the braking issues of passenger trains which have a great speed and frequent stops are examines. Problem statement: These processes are ехpensive and have big energy losses. The proposed solution to the problem: The kinetic energy of braking prosses propose to turn into thermal energy of heating fluid. For this purpose special hydraulic brake is proposed. The brake is connected with the wheel carriage pairs. The process is based on the energy dissipation in liqid when the disks with spikes rotate in it. Because the real liquid has friction and viscosity, it will be heat up, when the mechanical parts of the hydraulic brake are moved in it. The design, operating principle and characteristics of the hydraulic brake are proposed. Transmission of kinetic energy of carriage motion to brake system executed by mechanical clutches. It connected with the wheel pair and transmitting the energy the wheels rotation to hydraulic brake discs. The cylindrical rods are installed on the discs. Rods location fits the profile of the curved centrifugal pump vanes. As result, the fluid heatind prosess by rotatinge discs with rods take place also at the same time with the liquid pumping through the inner volume of brake system.Conclusions: Affordable passenger carriage braking dynamic is achieved by varying the size and number of rods. The heated liquid may be subsequently used for household needs and for heating the passenger carriage.

  19. Predict optimize the friction characteristics of brake pads; Brake pad no masatsu tokusei no yosoku to saitekika

    Energy Technology Data Exchange (ETDEWEB)

    Saotome, H. [Nissin Kogyo Co., Tokyo (Japan); Kato, T. [The University of Tokyo, Tokyo (Japan)

    1997-10-01

    The effect of the friction and the wear properties of brake pads were experimentally studied using a test rig of scale of 1/10 of the system used in a commercial car. The experimental data were investigated by the Multiple Regression Analysis and the Neural Network, and the effects of volume % of components on the friction and the wear properties were predicted. In addition the components of brake pads are optimized by Genetic Algorithms. 8 refs., 9 figs., 4 tabs.

  20. Matching Computation and Study on Vacuum Assist Brake System of Electric Vehicle%电动汽车真空助力制动系统的匹配计算与研究

    Institute of Scientific and Technical Information of China (English)

    张海军; 郝占武; 金叙龙; 李保权

    2012-01-01

    In this paper, vacuum assist brake system mathematics model is established with a mini vehicle as example, which provides calculation and analysis for the matching of vacuum assist brake system of the electric vehicle modified from fuel-powered vehicles, thus providing a theoretical basis for vacuum power brake system design and matching of the electric car, especially for the vacuum booster system, vacuum tank, vacuum booster, vacuum pump selection and matching. It is proved after test that selection of vacuum tank and vacuum pump valve value mentioned in this paper is reasonable, the operating duration of electric vacuum pump is 4-6 s.%以某微型汽车为例,建立了其真空助力制动系统的数学模型,对燃油汽车改装为电动汽车后的制动系统真空助力匹配进行了计算分析,从而为电动汽车真空助力系统中真空罐、真空助力器、真空泵的选型和匹配提供了理论依据.通过试验验证可知,本文的真空罐及真空泵阀值选择合理,电动真空泵工作时间为4~6 s.

  1. SRM应用于混合动力汽车再生制动系统的可行性分析%Feasibility analysis on application of switched reluctance motor in regenerative braking system of hybrid electrical vehicle

    Institute of Scientific and Technical Information of China (English)

    黄宝磊; 商高高; 童成前

    2012-01-01

    Start from the bask principle of switched reluctance motor (SRM), driving and generating principle is analyzed mainly.SRM is kind of motor which torque is generated by rotating the rotor to the location of maximum inductance of magnetic windingBy analyzing the requirements of motor performance features on regenerative braking system of HEV,and power generation process of SRM,the application of SRM in hybrid vehicle regenerative braking system is stated.The so-called regenerative braking system is a process of transforming part of kinetic energy into other forms of energy and reserving them for driving when the vehicle is decreasing or braking.Ttie system is feasible with great potential in application.%从开关磁阻电机(SRM)基本原理出发,重点分析其驱动发电运行原理.SRM是一种使转子运动到磁激励绕组电感最大化的位置而产生转矩的电机.通过分析混合动力汽车再生制动系统对电机性能特点的要求和SRM发电过程,说明了SRM应用于混合动力汽车再生制动,所谓再生制动,是指车辆减速或制动时,将其一部分动能转化为其他形式的能量储存起来以备驱动时使用的过程.系统是可行的,且应用潜力很大.

  2. Weight reduction of a standard brake drum: A design approach

    OpenAIRE

    D. Rambabu; Gopinath, R; U. Senthil rajan; G.B. Bhaskar

    2014-01-01

    A Brake drum is specialized brake that uses the concept of friction to decelerate the vehicle speed. The deceleration is achieved by the assistance of the friction generated by a set of brake shoes or pad, when operator presses against a rotating brake drum. The material generally preferred for making the brake drum is grey cast iron or vermicular cast iron. The drum brake is highly efficient for hand brake and service brake applications. During the operation of drum brake excessive heating o...

  3. 矿井摩擦式提升机制动装置在线监测系统设计%Design of an on-line monitoring system for brakes of mine friction hoists

    Institute of Scientific and Technical Information of China (English)

    姬程鹏; 张晓光; 毕伟; 卓蒙蒙

    2011-01-01

    根据国内现有矿井提升机特点,结合现代监测与诊断技术,设计开发了一种用于矿井摩擦式提升机制动装置的在线监测系统.介绍了系统构成、参数采集方案和故障诊断策略,并提出了利用制动减速度测量闸瓦摩擦系数的方法.试验表明,该系统性能良好,是提高提升机安全性、可靠性的一种行之有效的方法.%According to the characteristics of existing domestic mine hoists, an on-line monitoring system for the brake of the mine friction hoist is developed based on modem monitoring and diagnosis technology.The system structure, parameter acquisition scheme and fault diagnosis strategy are introduced, and a method of measuring the friction coefficient of the brake shoe by using braking deceleration is presented.The test indicates that the system has good performance, and is an effective way to improve security and reliability of the hoist.

  4. Plasma Braking Due to External Magnetic Perturbations

    Science.gov (United States)

    Frassinetti, L.; Olofsson, Kejo; Brunsell, P. R.; Khan, M. W. M.; Drake, J. R.

    2010-11-01

    The RFP EXTRAP T2R is equipped with a comprehensive active feedback system (128 active saddle coils in the full-coverage array) and active control of both resonant and non-resonant MHD modes has been demonstrated. The feedback algorithms, based on modern control methodology such as reference mode tracking (both amplitude and phase), are a useful tool to improve the ``state of the art'' of the MHD mode control. But this tool can be used also to improve the understanding and the characterization of other phenomena such as the ELM mitigation with a resonant magnetic perturbation or the plasma viscosity. The present work studies plasma and mode braking due to static RMPs. Results show that a static RMP produces a global braking of the flow profile. The study of the effect of RMPs characterized by different helicities will also give information on the plasma viscosity profile. Experimental results are finally compared to theoretical models.

  5. 基于Pro/E的直线电机型线控制动器结构设计%Linear motor type structure design of brake by wire system based on Pro/E

    Institute of Scientific and Technical Information of China (English)

    贾兴建

    2014-01-01

    在Pro/E环境下,针对直线电机线控制动器结构进行参数化设计,包括运动转换机构、H型机构及反力机构等。设计直线电机、垫板、楔形块、H型钳支架、制动盘和制动块等几何参数并建立他们之间的基本参数关系,利用Pro/E的拉伸、旋转、扫描功能将草绘图转换成三维实体图。在组件环境下将各零件组装为一体,完成直线电机型线控制动器结构设计,有效缩短了产品设计周期。%In the environment of Pro/E,parametric structure design of brake by wire system was carried out. Motion transformation mechanism,H type mechanism and counter force mechanism were included in the design. components such as linear motor,plate,wedge block,H clamp bracket,brake disc and brake block were designed,and their parametric relationship was established. Sketch was converted into 3D enti-tygraph by means of stretching,rotating and scanning. components were assembled together in the envi-ronment of Pro/E. Linear motor type structure design of brake by wire system was completed,and the de-sign cycle of the product was effectively shortened.

  6. Infrared characterization of thermal gradients on disc brakes

    Science.gov (United States)

    Panier, Stephane; Dufrenoy, Philippe; Bremond, Pierre

    2003-04-01

    The heat generated in frictional organs like brakes and clutches induces thermal distortions which may lead to localized contact areas and hot spots developments. Hot spots are high thermal gradients on the rubbing surface. They count among the most dangerous phenomena in frictional organs leading to damage, early failure and unacceptable braking performances such as brake fade or undesirable low frequency vibrations called hot judder. In this paper, an experimental study of hot spots occurrence in railway disc brakes is reported on. The aim of this study was to better classify and to explain the thermal gradients appearance on the surface of the disc. Thermograph measurements with an infrared camera have been carried out on the rubbing surface of brake discs on a full-scale test bench. The infrared system was set to take temperature readings in snap shot mode precisely synchronized with the rotation of the disc. Very short integration time allows reducing drastically haziness of thermal images. Based on thermographs, a classification of hot-spots observed in disc brakes is proposed. A detailed investigation of the most damaging thermal gradients, called macroscopic hot spots (MHS) is given. From these experimental researches, a scenario of hot spots occurrence is suggested step by step. Thanks to infrared measurements at high frequency with high resolution, observations give new highlights on the conditions of hot spots appearance. Comparison of the experimental observations with the theoretical approaches is finally discussed.

  7. Simulation and analysis of electric vehicle regenerative braking system with multiplex power supply%复合电源电动车再生制动系统的仿真与分析

    Institute of Scientific and Technical Information of China (English)

    戚思良; 盘朝奉; 陈昆山; 陈龙; 马跃超

    2013-01-01

    针对以蓄电池为单一车载电源的纯电动汽车存在着功率密度低、能量密度低、使用寿命短等缺点,将超级电容引入到纯电动汽车的储能系统中,组成了超级电容—蓄电池的复合电源结构.在MATLAB/SIMULINK环境下建立复合电源储能系统和驱动系统的仿真模型.基于搭建的实验平台参数,以可能多地利用电机再生制动力、最大程度实现制动能量的回收为目的制定制动力分配控制策略,根据标准市区循环工况进行再生制动仿真实验.结果表明,此再生制动系统回收了24%的制动能量,可以很好地弥补了蓄电池的低功率密度和低能量密度等缺陷,提高车载能量的利用率和车辆的动力性能,延长电动车的续驶里程.%Because storage battery used for driving the electric vehicle only has low power density, low energy density and other disadvantages, supercapacitor was applied to the energy storage system in battery electric vehicle to form a multiple energy supply system with battery. The multiple energy supply system model and driving system model were established via simulation environment of MATLAB/SIMULINK. In order to use more motor regenerative braking force and maximize braking energy recovery module, the braking force distribution control strategy was developed based on experiment platform parameter. The regenerative simulation test was conducted according to the power demands under standard urban driving cycle. The result shows that the regenerative braking system can recycled 24% braking energy. The multiple energy supply system can make up for the low power density, low energy density and other defects of car battery very well. It can improve the energy utilization ratio and the dynamic performance of the vehicle, and extend the driving range of electric cars.

  8. Robust Road Condition Detection System Using In-Vehicle Standard Sensors

    Directory of Open Access Journals (Sweden)

    Juan Jesús Castillo Aguilar

    2015-12-01

    Full Text Available The appearance of active safety systems, such as Anti-lock Braking System, Traction Control System, Stability Control System, etc., represents a major evolution in road safety. In the automotive sector, the term vehicle active safety systems refers to those whose goal is to help avoid a crash or to reduce the risk of having an accident. These systems safeguard us, being in continuous evolution and incorporating new capabilities continuously. In order for these systems and vehicles to work adequately, they need to know some fundamental information: the road condition on which the vehicle is circulating. This early road detection is intended to allow vehicle control systems to act faster and more suitably, thus obtaining a substantial advantage. In this work, we try to detect the road condition the vehicle is being driven on, using the standard sensors installed in commercial vehicles. Vehicle models were programmed in on-board systems to perform real-time estimations of the forces of contact between the wheel and road and the speed of the vehicle. Subsequently, a fuzzy logic block is used to obtain an index representing the road condition. Finally, an artificial neural network was used to provide the optimal slip for each surface. Simulations and experiments verified the proposed method.

  9. 汽车辅助制动系统及试验方法研究%Study on Automotive Auxiliary Braking System and Test Method

    Institute of Scientific and Technical Information of China (English)

    王勇; 张雄; 刘翰东

    2013-01-01

    The authors introduce the type and principles of the auxiliary braking types, and describe the require-ments and test methods of typeⅡand typeⅡA tests. Through simulating the ramp test, they verify the meeting of the exhaust braking and the retarder braking to the standard, and put forward the relative recommendations.%介绍辅助制动装置的类型及原理,并对Ⅱ型和ⅡA型试验的要求和试验方法进行阐述。通过模拟坡道试验,验证排气制动和缓速器对标准的满足性,并给出相应建议。

  10. 基于Zigbee Pro技术的列车制动试风测控系统%Train Air Brake Test System Baed on Zigbee Pro Technology

    Institute of Scientific and Technical Information of China (English)

    胡邦南

    2013-01-01

    A train air brake test system based on Zigbee Pro wireless sensor network was discussed. The first layer is industrial PC, responsible for the management. The second layer is the main control machine composed of touch screen and programmable logic controller,responsible for measurement and control. The third layer is the pressure measurement device at the train tail,responsible for the reliable long-distance data transmission and measurement of the pressure at the train tail. The key points in design and implementation were analyzed, such as the network structure, communication protocol, portable pressure measurement device at the train tail,the main control machine. The system's running shows it has high measurement and control precision,is a complete automatization system with high reliability, flexible expansibility and low operating expense.%文中论述了一种基于Zigbee Pro无线传感器网络的列车制动试风测控系统.系统第一层为工控机,负责管理;第二层为触摸屏和可编程控制器构成的控制主机,负责测量和控制;第三层为列尾气压采集器,负责列尾气压的测量和远距离数据传输.分析了设计和实现中的关键技术,如网络结构、通信协议、便携式列尾气压采集器、控制主机等.实际运行表明:系统测量和控制精度高,实现完全自动化,具有可靠性高、可扩展性强、运行费用低等优点.

  11. 机车制动机现场培训考试系统的研究%Research on the On-site Training Exam System of Automotive Braking Machine

    Institute of Scientific and Technical Information of China (English)

    张玲

    2015-01-01

    The on-site training exam system of automotive braking machine was devised and developed with the pneumatic technology on the basis of liquid mechanics theory aimed at the problems such as short time of cultivation for the locomotive drivers, insufficient experience, and unskilled degree of controlling the locomotive, low accuracy to the estimation of the phenomenon. It was applied in the training of steward and achieved distinct effect, enhanced the level for steward to operate braking machine and judge the train braking pipe accurately.%针对目前普遍存在机车司机培养时间短、 经验不足, 对机车操纵的熟练程度及对现象判断的准确性不高的问题, 采用气动技术、 依据流体力学理论, 设计开发了机车制动机现场培训考试系统. 经过在乘务员培训中的应用, 取得明显的效果, 提高了乘务员的制动机操作水平和对列车管判断的准确性.

  12. RELIABILITY ANALYSIS OF CRANE BRAKE PARAMETERS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The high failure rate of crane brake results from improper choice of braking torque. The mathematical model of reliability for the crane brake parameters is introduced. Based on large amount of actual data the parameter reliabilities of 5~50 t general overhead travelling cranes are calculated,the probabilities that the braking torque is less than the static torque acting on the axle when the load moves down are obtained. Moreover,the ways to improve the reliability of brake parameters are discussed,the most reasonable values of braking safety coefficient are given.

  13. Analysis of the stability of PTW riders in autonomous braking scenarios.

    Science.gov (United States)

    Symeonidis, Ioannis; Kavadarli, Gueven; Erich, Schuller; Graw, Matthias; Peldschus, Steffen

    2012-11-01

    While fatalities of car occupants in the EU decreased remarkably over the last decade, Powered Two Wheelers (PTWs) fatalities still increase following the increase of PTW ownership. Autonomous braking systems have been implemented in several types of vehicles and are presently addressed by research in the field of PTWs. A major concern in this context is the rider stability. Experiments with volunteers were performed in order to find out whether autonomous braking for PTWs will produce a greater instability of the rider in comparison to manual braking. The PTW's braking conditions were simulated in a laboratory with a motorcycle mock-up mounted on a sled, which was accelerated with an average of 0.35 g. The motion of the rider was captured in autonomous braking scenarios with and without pre-warning as well as in manual braking scenarios. No significant differences between the scenarios were found with respect to maximum forward displacement of the volunteer's torso and head (pautonomous braking at low deceleration will not cause significant instabilities of the rider in comparison to manual braking in idealized laboratory conditions. Based on this, further research into the development and implementation of autonomous braking systems for PTWs, e.g. by extensive riding tests, seems valuable.

  14. Squeal analysis of ventilated disc brake using ansys

    Directory of Open Access Journals (Sweden)

    Ahmed Abdel-Naser, Ibrahim Ahmed, Essam Allam, Sabry Allam, Shawki Abouel-seoud

    2012-01-01

    Full Text Available It is well-known that automobile brakes can generate several kinds of noises. Among them is squeal, a noise in the 1-15 kHz range. It is commonly accepted that brake squeal is initiated by instability due to the friction forces, leading to self excited vibrations. To predict the onset of brake instability, a modal analysis of the prestressed structure can be performed on an improved dynamic finite element model of ventilated disc brake with friction coupling. An unsymmetric stiffness matrix is a result of the friction coupling between the brake pad and disc; this may lead to complex eigenfrequencies. The complex eigenvalue method (Unsymmetric solver used to analyse mode shapes associated with the predicted natural frequency. Creating the element of Matrix27 between the ventilated disc and pad was very important in studying the squeal of the coupled ventilated disc brake. The results demonstrated that the FEM for the coupled ventilated rotor and pad showed a good interaction between the non-linear contact and the linear modal analysis. Furthermore, the unsymmetric solver showed that the modes of the coupled disc-pad contained two types of mode. The first type was normal mode, which did not contain an imaginary part while the second type was complex mode that contained real and imaginary parts. Moreover, complex eigenvalue analysis predicted always more unstable modes than the number of squeal frequencies that really occur in the brake system. The maximum squeal index was observed at mode 16 and at frequency of 4083 Hz with instability of 480 sec-1. However; the tendency of instability (TOI for the system at contact stiffness of 1 GN/m was 59 that gave the lowest instability of the system.

  15. Analysis of brake condition and parameter matching of hybrid energy storage system for hybrid electric vehicles%混合动力车制动工况分析与储能装置参数匹配

    Institute of Scientific and Technical Information of China (English)

    王伟达; 王言子; 项昌乐; 刘辉

    2014-01-01

    为提高混合动力系统整体性能,实现高效能量回收,分析某重型越野车辆驾驶循环工况中制动过程的功率与能量分布,从制动能量回收率与电机参数出发讨论对储能装置的性能要求。提出电池组-超级电容复合储能装置的参数匹配方法,针对21 t级试验样车混合动力系统进行实例计算,论证锂离子电池组与超级电容组成的复合储能装置的性能。实例计算与道路试验结果表明:匹配的复合储能装置符合车辆整体性能与制动能量回收的要求,体积、重量满足总体设计约束;匹配超级电容后,储能装置的瞬时功率能力大幅提升,可显著提高车辆的制动能力和制动能量回收率。%According to the driving cycle of heavy off-road vehicles, the brake power and energy permutation is analyzed, and the performance requirement for the hybrid energy storage system( HESS) is achieved based on the brake energy recovery rate and motor parameters. The parameter matching method for the HESS is proposed and by which the instance calculation for the hybrid propulsion system of 21 tons class vehicles is carried out, and the performance of the HESS with Li-ion cells and ultra capacitors is discussed too. The instance calculation and the test results indicate that the designed HESS can meet the requirement of the total performance of the HEV and the brake energy recovery, the volume and weight answer for the restriction of the top design of the HEV. The designed HESS with ultra capacitors can increase the transient power volume greatly and the brake performance and the brake energy recovery rate are enhanced remarkably.

  16. Stability Control of Vehicle Emergency Braking with Tire Blowout

    Directory of Open Access Journals (Sweden)

    Qingzhang Chen

    2014-01-01

    Full Text Available 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 a safe speed in an expected trajectory. The simulating test system is also designed, and the testing results show that the vehicle can be quickly stabilized and kept in the original track after tire blowout with the emergency braking system described in the paper.

  17. Thermal Modeling of Disc Brake Rotor in Frictional Contact

    Science.gov (United States)

    Ali, Belhocine; Ghazaly, Nouby Mahdi

    2013-01-01

    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 analyze 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. The analysis also gives us, the heat flux distribution for the two discs.

  18. 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

  19. BRAKING OF HIGH-SPEED PASSENGER TRAINS WITH REGARD TO THE OPERATION OF AN ELECTROMAGNETIC RAIL BRAKE

    Directory of Open Access Journals (Sweden)

    N. Je. Naumenko

    2009-03-01

    Full Text Available The research of the braking process of high-speed passenger train with the use of compressed-air, electropneumatic and electromagnetic track brakes is carried out. The dependences of braking distance on motion speed for vehicles equipped by block or disk brakes as well as for a case of electromagnetic track brakes used in addition to existing braking means.

  20. Braking Performance of a Biomimetic Squid-Like Underwater Robot

    Institute of Scientific and Technical Information of China (English)

    Md.Mahbubar Rahman; Sinpei Sugimori; Hiroshi Miki; Risa Yamamoto; Yugo Sanada; Yasuyuki Toda

    2013-01-01

    In this study,the braking performance of the undulating fin propulsion system ofa biomimetic squid-like underwater robot was investigated through free run experiment and simulation of the quasi-steady mathematical model.The quasi-steady equations of motion were solved using the measured and calculated hydrodynamic forces and compared with free-run test results.Various braking strategies were tested and discussed in terms of stopping ability and the forces acting on the stopping stage.The stopping performance of the undulating fin propulsion system tured out to be excellent considering the short stopping time and short stopping distance.This is because of the large negative thrust produced by progressive wave in opposite direction.It was confirmed that the undulating fin propulsion system can effectively perform braking even in complex underwater explorations.

  1. Magnetic braking in ultracompact binaries

    CERN Document Server

    Farmer, Alison

    2010-01-01

    Angular momentum loss in ultracompact binaries, such as the AM Canum Venaticorum stars, is usually assumed to be due entirely to gravitational radiation. Motivated by the outflows observed in ultracompact binaries, we investigate whether magnetically coupled winds could in fact lead to substantial additional angular momentum losses. We remark that the scaling relations often invoked for the relative importance of gravitational and magnetic braking do not apply, and instead use simple non-empirical expressions for the braking rates. In order to remove significant angular momentum, the wind must be tied to field lines anchored in one of the binary's component stars; uncertainties remain as to the driving mechanism for such a wind. In the case of white dwarf accretors, we find that magnetic braking can potentially remove angular momentum on comparable or even shorter timescales than gravitational waves over a large range in orbital period. We present such a solution for the 17-minute binary AM CVn itself which a...

  2. Compact, Lightweight Servo-Controllable Brakes

    Science.gov (United States)

    Lovchik, Christopher S.; Townsend, William; Guertin, Jeffrey; Matsuoka, Yoky

    2010-01-01

    Compact, lightweight servo-controllable brakes capable of high torques are being developed for incorporation into robot joints. A brake of this type is based partly on the capstan effect of tension elements. In a brake of the type under development, a controllable intermediate state of torque is reached through on/off switching at a high frequency.

  3. Braking performance of aircraft tires

    Science.gov (United States)

    Agrawal, Satish K.

    This paper brings under one cover the subject of aircraft braking performance and a variety of related phenomena that lead to aircraft hydroplaning, overruns, and loss of directional control. Complex processes involving tire deformation, tire slipping, and fluid pressures in the tire-runway contact area develop the friction forces for retarding the aircraft; this paper describes the physics of these processes. The paper reviews the past and present research efforts and concludes that the most effective way to combat the hazards associated with aircraft landings and takeoffs on contaminated runways is by measuring and displaying in realtime the braking performance parameters in the aircraft cockpit.

  4. 基于微粒群算法的汽车底盘控制系统集成优化%Simultaneous optimization design of vehicle chassis integrated control system based on particle swarm optimization algorithm

    Institute of Scientific and Technical Information of China (English)

    刘显贵; 陈无畏; 罗善明; 钟铭恩

    2015-01-01

    interferences between the mechanical structure and control system of vehicle chassis system and to further enhance the overall performance of vehicle, the method of simultaneous optimization of mechanical structure and controller parameters of vehicle chassis system based on Particle Swarm Optimization Algorithm is presented in this paper. According to the fundamental principle of vehicle dynamics, a half car mode of active suspension system and anti-lock braking systems established at first. Then the linear quadratic gauss controller of the active suspension system and sliding mode controller of anti-lock braking system are designed. Taking controllers designed for active suspension system and anti-lock braking system as bottom controllers, the upper coordinated control logic of the systems is put forward and the upper PID coordinated controller is designed on the basis of analyzing the coupling conflict between active suspension system and anti-lock braking system. Finally, a Particle Swarm Optimization Algorithm was adopted for simultaneous optimization of mechanical structure and controller parameters of vehicle chassis integrated control system, because the traditional design method of a vehicle system is always to design control parameters following structure parameters and it can not obtain the global optimal performances for the system. In order to verify the effectiveness of the algorithm, the simultaneous optimization program is developed based on Particle Swarm Optimization Algorithm in MATLAB environment while the mechanical structure and control parameters of chassis control system are set as optimization variables and the overall vehicle dynamics performance is set as objective function. Simulation result shows that the pitching angular acceleration of vehicle is reduced and vehicle riding comfort performance is improved after optimized. Braking distance and dynamic load of front and rear wheels of vehicle are also reduced significantly which indicating vehicle

  5. Angular momentum loss in the envelope-disk transition region of HH 111 protostellar system: evidence for magnetic braking?

    CERN Document Server

    Lee, Chin-Fei; Li, Zhi-Yun

    2016-01-01

    HH 111 is a Class I protostellar system at a distance of ~ 400 pc, with the central source VLA 1 associated with a rotating disk deeply embedded in a flattened envelope. Here we present the observations of this system at ~ 0.6" (240 AU) resolution in C18O (J=2-1) and 230 GHz continuum obtained with Atacama Large Millimeter/Submillimeter Array, and in SO obtained with Submillimeter Array. The observations show for the first time how a Keplerian rotating disk can be formed inside a flattened envelope. The flattened envelope is detected in C18O, extending out to >~ 2400 AU from the VLA 1 source. It has a differential rotation, with the outer part (>~ 2000 AU) better described by a rotation that has constant specific angular momentum and the innermost part (<~ 160 AU) by a Keplerian rotation. The rotationally supported disk is therefore relatively compact in this system, which is consistent with the dust continuum observations. Most interestingly, if the flow is in steady state, there is a substantial drop in ...

  6. Product and process innovation of grey cast iron brake discs

    Energy Technology Data Exchange (ETDEWEB)

    Schorn, M. [Brembo S.P.A. (Italy)

    2006-07-01

    The brake disc out of grey cast iron often seems to be playing the role of the ''underdog'' in the technical examinations of the entire brake system. This is also reflected by the 25 year history of the {mu}-club. In a total of 93 presentations in those 25 years, only 3 were related to the topic of grey cast iron discs. This is not a correct relation to the importance of this component within the brake system. The disc, although per definition with a lower specific load than the pad, has the major task to store and dissipate the heat in which the kinetic energy of the vehicle is transformed. The disc also has a significant effect on NVH behaviour, particularly in the low frequency range. It also has a permanent fight with its weight as an unsprung mass. (orig.)

  7. 纯电动汽车电—液复合制动系统控制算法的多边界条件优化设计%Optimization Design of EV Electro—Hydraulic Composite Braking System Control Algorithm with Multi—boundary Conditions

    Institute of Scientific and Technical Information of China (English)

    李玉芳; 周丽丽

    2012-01-01

    According to the characteristics of pure EV power system, an optimization design method of brake force control algorithm of electro-hydraulic composite brake system with multi - boundary conditions was proposed. And based on the analysis of boundary conditions, including the braking strength requirements, ECE regulations, and motor/battery characteristics etc, a reasonable range of brake force distribution ratio was achieved. And braking force distribution approach between the front and rear axles was brought out by considering such factors as the braking strength of demand and using frequency of the various adhesion coefficient roads. And the simulation analysis verifies the rationality and effectiveness of the brake force distribution algorithm.%根据纯电动汽车动力系统的特点,提出电—液复合制动系统控制算法的多边界条件优化设计方法.基于对制动强度需求、ECE法规和电机/蓄电池特性等多边界条件的分析,得出制动力分配比例的合理取值范围,以此为基础,提出根据制动强度需求和不同附着系数路面的使用频率等因素确定前后轴制动力分配系数的方法.仿真分析验证了制动力分配算法的有效性和合理性.

  8. 集成式电子液压制动系统鲁棒性液压力控制%Robustness Hydraulic Pressure Control System of Integrated-electro-hydraulic Brake System

    Institute of Scientific and Technical Information of China (English)

    余卓平; 徐松云; 熊璐; 广学令

    2015-01-01

    A robustness control system is presented to fulfill the requirements of hydraulic pressure control of integrated-electro- hydraulic brake system. Based on the analysis of chararistics of system it is found that integrated-electro-hydraulic brake system is a nonlinear time-varying system. It is affected by ambient temperature, humidity, load disturbance and other uncertain factors and oscillation occurs. In order to solve these problems the control system of I-EHB is required to have a good adaptation for external uncertain disturbance. Using Taguchi method which is modified according to the system a robustness hydraulic pressure control system for integrated-electro-hydraulic brake system is formed. Using the test rig this robustness control system is tested. Results show that this robustness control system responded rapidly and has a good robustness. In 500 experiments the system keeps in stability. Hence a new method for the control system design of nonlinear time-varying system is found. By using this method the output of system is insensitive to external disturbance, the robustness of system is improved and the performance of system is optimized.%面向汽车集成式电子液压制动系统需求,设计一种鲁棒性液压力控制系统。基于系统特性分析发现,集成式电子液压制动系统为非线性时变系统,其工作受到温度、湿度、载荷扰动等多重不确定因素的影响,容易产生振荡的现象。因此要求液压力控制系统对外界不确定的扰动有较强的适应性,同时满足指标要求。利用基于系统改进的田口方法,提出一种集成式电子液压制动系统鲁棒性液压力控制方法。建立相关试验平台并利用该方法实现液压力鲁棒性控制。试验结果表明,所设计的鲁棒性液压力控制方法鲁棒性强,响应迅速,在500次试验内均保持稳健。因此,研究为非线性时变控制系统设计找到了一个新的设计方法,运

  9. The Coordination Control Strategy of Transmission System and Braking System for Mine Vehicle%矿用车辆传动与制动系统协调控制策略

    Institute of Scientific and Technical Information of China (English)

    南黄河

    2015-01-01

    针对矿用车辆在使用过程中出现的传动件损坏及溜车问题,对整车传动系统及制动系统的原理及组成进行了分析,并对车辆的使用状况进行了调研。为避免传动件损坏及溜车问题的再次发生,研制了一种减压装置,对液压制动系统的压力进行减压,进而实现制动过程中动力换挡变速箱动力的切断功能,减小制动过程中传动件的受力;并采用两位三通液控换向阀使发动机在熄火状态下整车能够自动实现制动功能。使用结果表明:采用减压装置后有效地减少了传动轴、变速箱离合器摩擦片等传动件的磨损,使用两位三通液控换向阀后整车从未发生过溜车现象。通过采取这些措施,可提高矿用车辆运行的可靠性和安全性。%For the problems of the transmission parts damage and sliding accident in using the mine vehicle,the principle and composition of the vehicle transmission system and the brake system were analyzed,and the behavior in the service of vehi-cles were investigated. In order to avoid from the transmission parts damage and sliding accident again,a pressure-relief device which could relieve the pressure of hydraulic braking system was developed to cut off the power in transmission and to realize the power cutoff in power gearshift gear-box,and then the load of transmission parts were reduced in the braking process. The 2-position 3-way hydraulic operated directional valve was used to realize the automatic braking function in the flameout of the engine. Results showed that:the damage on transmission parts including transmission shaft,transmission clutch friction plate and other parts were reduced effectively by using the pressure-relief device,and sliding accident never happened by adopting 2-position 3-way hydraulic operated directional valve. Through these measures,the safety and reliability in operating the mine ve-hicle were improved.

  10. Mechanism for Electro-Magnetic Interference in an Aircraft′s Electric Braking System and Its Suppression Method%飞机电刹车系统电磁干扰产生机理及抑制方法

    Institute of Scientific and Technical Information of China (English)

    相里康; 马瑞卿; 张庆超; 韩伟健; 邓钧君

    2015-01-01

    This paper deals with the problem that the signals of the force sensor of an aircraft′s electric braking sys⁃tem are superimposed with high⁃amplitude interference. The analysis of the electric braking system shows that the three⁃phase current of its motor and the pulse width modulation (PWM) wave output by the electro⁃mechanical ac⁃tuator controller (EMAC) are the primary sources of interference and that the coupling interference between cable lines is the main cause of the interference of signals of the force sensor. The mathematical model of coupling inter⁃ference between cable lines is established, according to which the transmission cable is designed and the line cou⁃pling was reduced by using electromagnetic shielding, line twisting and effective grounding. A passive electromag⁃netic interference (EMI) filter is designed for the output end of the EMAC. Through these improvements, the inter⁃ference superimposed on the force sensor is greatly reduced. The paper also improves the electromagnetic compati⁃bility of the electric braking system and ensures that the braking force servo system works normally.%针对飞机电刹车系统力传感器信号上叠加有高幅干扰这一问题,通过对电刹车系统分析,认为电机三相电流以及机电作动控制器(EMAC)输出 PWM 波为主要干扰源,电缆线路之间的耦合干扰是造成干扰的主要原因。建立了线路耦合干扰的数学模型,并据此采用电磁屏蔽、线路绞合和有效接地来减少线路耦合,并在 EMAC 输出端设计了无源 EMI 滤波器。通过这些改进,极大地减弱了干扰,提高了系统电磁兼容性,保证了刹车力伺服系统正常工作。

  11. Thermal-mechanical coupled analysis of a brake disk rotor

    Science.gov (United States)

    Belhocine, Ali; Bouchetara, Mostefa

    2013-08-01

    The main purpose of this study is to analyze the thermomechanical behavior of the dry contact between the brake disk and pads during the braking phase. The simulation strategy is based on computer code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles The thermal-structural analysis is then used with coupling to determine the deformation and the Von Mises stress established in the disk, the contact pressure distribution in pads. The results are satisfactory when compared to those of the specialized literature.

  12. Design of Vehicle Electric Parking Brake System Based on CAN Bus%基于CAN总线的车辆电子驻车制动系统的设计

    Institute of Scientific and Technical Information of China (English)

    辛改芳; 李威

    2013-01-01

    CAN bus-based electric parking brake system was proposed for the deficiencies of the manual parking brake system used currently, such as complicated operation, huge institution, elongation of the cable. This paper presented CAN communication interface circuit and application layer protocol definition of CAN bus, achieved intelligent control for the left and right rear wheel integration using the proposed control strategy. The system can reduce the difficulty of the drivers operation and improve driving comfort and safety.%针对目前使用的手动驻车制动系统操作繁琐、机构庞大、钢索容易变形伸长等不足,提出了基于CAN总线的电子驻车制动系统的模块化设计方案,详细介绍了电子驻车制动控制系统的CAN通讯接口电路及CAN总线应用层协议的定义,实现了对左、右后车轮一体化执行机构的智能化控制.该系统可以降低驾驶员的操作难度,提高驾驶的舒适性、安全性.

  13. Modeling of automotive drum brakes for squeal and parameter sensitivity analysis

    Science.gov (United States)

    Huang, Jinchun; Krousgrill, Charles M.; Bajaj, Anil K.

    2006-01-01

    Many fundamental studies have been conducted to explain the occurrence of squeal in disc and drum brake systems. The elimination of brake squeal, however, still remains a challenging area of research. Here, a numerical modeling approach is developed for investigating the onset of squeal in a drum brake system. The brake system model is based on the modal information extracted from finite element models for individual brake components. The component models of drum and shoes are coupled by the shoe lining material which is modeled as springs located at the centroids of discretized drum and shoe interface elements. The developed multi degree of freedom coupled brake system model is a linear non-self-adjoint system. Its vibrational characteristics are determined by a complex eigenvalue analysis. The study shows that both the frequency separation between two system modes due to static coupling and their associated mode shapes play an important role in mode merging. Mode merging and veering are identified as two important features of modes exhibiting strong interactions, and those modes are likely candidates that lead to coupled-mode instability. Techniques are developed for a parameter sensitivity analysis with respect to lining stiffness and the stiffness of the brake actuation system. The influence of lining friction coefficient on the propensity to squeal is also discussed.

  14. 飞机电传刹车半实物仿真技术的研究%Research on Hardware in the Loop Simulation Technology Applied on Aircraft Electric Braking System

    Institute of Scientific and Technical Information of China (English)

    苏田青; 林辉

    2012-01-01

    A project from C code directly generated by Simulink models was built which could be applied on Texas Instruments C28335 development board and a hardware in the loop simulation platform was established which could be applied on any kind of aircraft braking system. Simulation and experiment results show that automatic generated code has high accuracy and efficiency and can greatly reduce development period. The hardware in the loop simulation platform runs stably and simulation results show no difference with the real braking process and satisfy the system demands.%实现了由Simulink框图直接生成可用于TI公司C28335控制器的C代码程序,建立了某型号的飞机电传刹车半实物仿真和实验系统.仿真和实验结果表明,自动生成的代码准确度高、效率高,大大缩短开发周期;半实物仿真系统运行稳定,仿真结果达到项目指标,一致性较好,满足系统要求.

  15. EFFECT OF GENDER DIFFERENCE ON BRAKE REACTION TIME

    Directory of Open Access Journals (Sweden)

    Ashok

    2016-02-01

    Full Text Available BACKGROUND OF THE STUDY Reaction time is the time taken to respond to a stimulus or change in the environment. It is a method to assess the time taken from the perception of a stimulus followed by mental processing for a motor response. Reaction time in various day to day activities as in driving a car is very important. Brake reaction time (BRT is the time taken for the driver to respond to visualize an object and to press the brake pedal. It is affected by many features like age, gender, neuromuscular disorders. OBJECTIVE OF THE STUDY Study has been undertaken to compare the BRT in male and female drivers and to analyze the effect of sex difference on Brake reaction time. MATERIALS & METHODS Male and female subjects between the age group of 25 – 35 years with driving license were included. Study is conducted in a stationary car. An in-house built; braking timer is fixed to the electric circuit of the braking system in the car. This device is wirelessly connected to the reaction time software installed in the laptop. The subject is instructed to press the brake pedal when the light changed from red to green in the laptop screen. 5 readings are taken and the mean BRT is recorded. STATISTICAL ANALYSIS & RESULTS Statistical analysis done with unpaired student t test indicates that the BRT was more in the females than the males and was statistically significant (p value - 0007. CONCLUSION Gender difference has a significant effect on BRT and reaction time in female is longer than for the males.

  16. Effect of coordination of optimal reclosing and fuzzy controlled braking resistor on transient stability during unsuccessful reclosing

    OpenAIRE

    Ali, Mohd.Hasan; Murata, Toshiaki; Tamura, Junji

    2006-01-01

    This paper analyzes the effect of the coordination of optimal reclosing and fuzzy logic-controlled braking resistor on the transient stability of a multimachine power system in case of an unsuccessful reclosing of circuit breakers. The transient stability performance of the coordinated operation of optimal reclosing and fuzzy controlled braking resistor is compared to that of the coordinated operation of conventional auto-reclosing and fuzzy controlled braking resistor. The effectiveness of t...

  17. 重载列车制动管路对制动性能的影响%Influence of braking pipe on braking performance for heavy haul train

    Institute of Scientific and Technical Information of China (English)

    魏伟; 杜念博

    2011-01-01

    应用流体动力学理论,建立了重载列车制动管路模型与分配阀模型,求解了制动管路和边界点的动力学方程,仿真计算了制动过程中的制动系统性能,分析了列车主管和支管长度对制动系统性能的影响。分析结果表明:当列车主管长度由13.24 m增大为17.24 m时,在常用制动下,列车管路减压时间增大了30.75%,制动缸升压时间增大了20.45%,主管长度对常用制动的影响要强于对紧急制动的影响;当列车支管长度由0.50 m增大到5.00 m时,在常用制动下,列车管路减压时间增大了6.63%,制动缸升压时间增大了5.22%,支管长度对常用制动和紧急制动影响程度差别不大。列车制动管路长度增大降低了列车制动管路减压速度与制动缸升压速度;列车主管长度对制动性能的影响要明显大于列车支管长度的影响,车辆位置距机车越远影响越明显。%With fluid dynamics theory,the models of braking pipe and distributing valve for heavy haul train were built,the equations of braking pipe and boundary point were solved,the braking system performances in braking process were simulated,and the influence of the lengths of main pipe and branch pipe on the braking performances was analyzed.Analysis result shows that under common braking,when the length of main pipe increases from 13.24 m to 17.24 m,the decompression time of braking pipe increases by 30.75%,and the boost time of braking cylinder increases by 20.45%.The influence of main pipe on common braking is even stronger than that of main pipe on emergency braking.Under common braking,when the length of branch pipe increases from 0.50 m to 5.00 m,the decompression time of braking pipe increases by 6.63%,and the boost time of braking cylinder increases by 5.22%.The influence of branch pipe on common braking is almost same for that of branch pipe on emergency braking.The increase length of braking pipe reduces the decompression speed of braking pipe

  18. Tribology of a Combined Yaw Bearing and Brake for Wind Turbines

    DEFF Research Database (Denmark)

    Poulios, Konstantinos

    that are affected by the tendency for building larger units, is the yaw system of horizontal axis wind turbines. State of the art wind turbine yaw systems consist of either a large roller element bearing or a corresponding segmented sliding bearing that connects the wind turbine nacelle and tower. An additional...... disc brake is typically included as an independent system. However, the increasing size of wind turbines makes roller element bearings an economically costly option. Moreover, the additional brake system increases complexity and consequently adds further production and maintenance costs. One...... of the innovations aiming at reducing complexity in the yaw system consists in combining a segmented sliding bearing and a brake into a single system. This thesis studies the tribological implications of such a hybrid sliding bearing and brake for the yaw system of wind turbines. Based to a large extent...

  19. Friction Wear Property of Brake Materials by Copper-based Powder Metallurgy With Various Brake Speeds

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-xiu; GAO Hong-xia; WEI Xiu-lan

    2004-01-01

    The experiment is conducted on MM-1000 friction test machine, which tests friction wear property of copper-based brake materials by powder metallurgy at different brake speeds. It shows that the coefficient of friction and wear volume are greatly influenced by brake speed. When the brake speed is 4000 r/min, which is a bit higher, the material still has a higher coefficient of friction with 0.47. When the brake speed is over 4000r/min, the coefficient of friction decreased rapidly. When the brake speed is 3000r/min, the material's wear is in its minimum. That is to say no matter how higher or lower the brake speed is the wear volume is bigger relatively. With the brake speed of the lower one it mainly refers to fatigue wear; while of higher one it mainly refers to abradant and oxidation wear.

  20. 运行中动车组制动系统故障原因分析及处理%An Analysis on The Fault Causes in Braking System of Bullet Train During Operatqion and Processing

    Institute of Scientific and Technical Information of China (English)

    尹凤伟

    2015-01-01

    Since the 6th national railway speed upgrade in April 18th 2007 and the first time to run multiple units at the speed of 200km/h in China,the CRH series which is called "Harmony",in general has become a symbol marking that China' railway has stepped on the club of high-speed railway.As for multiple units,the braking system is related to safety,and it is also an important factor for railway speed upgrade.The speed-up of railway need high-power traction and besides, the braking capacity shall be completely powerful.%我国铁路自2007年4月18日进行第六次大提速,并在国内首次开行时速200km动车组以来,统称为"和谐号"的CRH系列动车组即成为我国铁路迈入高速铁路俱乐部的象征.对于动车组来说,制动系统既关系到安全问题,也是列车提速的重要因素.列车的提速,除了要有大功率牵引外,还必须有足够强大的制动能力.

  1. What brakes the Crab pulsar?

    Science.gov (United States)

    Čadež, A.; Zampieri, L.; Barbieri, C.; Calvani, M.; Naletto, G.; Barbieri, M.; Ponikvar, D.

    2016-03-01

    Context. Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. Aims: The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. Methods: We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. Results: From our analysis, we demonstrate that the power law index undergoes "instantaneous" changes at the time of observed jumps in rotational frequency (glitches). We find that the phase evolution of the Crab pulsar is dominated by a series of constant braking law episodes, with the braking index changing abruptly after each episode in the range of values between 2.1 and 2.6. Deviations from such a regular phase description behave as oscillations triggered by glitches and amount to fewer than 40 turns during the above period, in which the pulsar has made more than 2 × 1010 turns. Conclusions: Our analysis does not favor the explanation that glitches are connected to phenomena occurring in the interior of the pulsar. On the contrary, timing irregularities and changes in slow down rate seem to point to electromagnetic interaction of the pulsar with the surrounding environment.

  2. Chain of impact of the development of hot spots and hot rubbing in disk brakes of passenger cars; Wirkungskette der Entstehung von Hotspots und Heissrubbeln in Pkw-Scheibenbremsen

    Energy Technology Data Exchange (ETDEWEB)

    Sarda, Angelo

    2009-07-01

    Aspects coupled with brake comfort represent challenges with the development of brake systems. During the brake process, so-called hot spots on the surface of brake disks are developed under certain conditions. These hot spots result in an irregular thermal expansion and deformation of the brake disk. This results in vibrations impacting the comfort and being known as 'hot rubbing'. The author of the contribution under consideration describes the most important results from extensive benchmark tests and supplies experimentally secured realizations to the chain of impact of the development of hot spots and 'hot rubbing' in a disc brake.

  3. CFD design analysis of ventilated disc brakes

    OpenAIRE

    Pulugundla, Gautam

    2008-01-01

    This thesis reports the numerical investigation of the automotive ventilated disc brake rotor. Disc brakes operate on the principle of friction by converting kinetic energy into heat energy. The main objective of a disc brake rotor is to store this heat energy and dissipate it as soon as possible. This work is carried out in a area where there is very limited understanding. Commercial CFD code FLUENT was used for carrying out the simulations with the rotor rotating in still ...

  4. Aerodynamic investigations of ventilated brake discs.

    OpenAIRE

    Parish, D.; MacManus, David G.

    2005-01-01

    The heat dissipation and performance of a ventilated brake disc strongly depends on the aerodynamic characteristics of the flow through the rotor passages. The aim of this investigation was to provide an improved understanding of ventilated brake rotor flow phenomena, with a view to improving heat dissipation, as well as providing a measurement data set for validation of computational fluid dynamics methods. The flow fields at the exit of four different brake rotor geometrie...

  5. BRAKE TEST OF SiCp/A356 BRAKE DISK AND INTERPRETATION OF EXPERIMENTAL RESULTS

    Institute of Scientific and Technical Information of China (English)

    YANG Zhiyong; HAN Jianmin; LI Weijing; WANG Jinhua

    2007-01-01

    Material properties are obvious different between aluminum matrix composites and iron and steel materials. After the brake disk braked at the same speed, the average temperature of the aluminum brake disk is 1.5 times as high as one of iron and steel brake disk, the thermal expansion value of the aluminum brake disk is 2 times as big as one of iron and steel brake disk. Mechanical property of the material decreases with the temperature increasing generally during braking, on the other hand, the big thermal stress in the brake disk happens because the material expansion is constrained. Firstly, the reasons of the thermal stress generation and the fracture failure of brake disks during braking are analyzed qualitatively by virtue of three-bar stress frame and sandwich deformation principles in physic, and then the five constraints which cause the thermal stress are summarized. On the base of the experimental results on the 1:1 emergency brake test, the thermal stress and temperature fields are simulated; The behavior of the fracture failure is interpreted semi-quantitatively by finite element analysis. There is the coincident forecast for the fraction position in term of the two methods. In the end, in the light of the analysis and calculation results, it is the general principles observed by the structure design and assembly of the brake disk that are summarized.

  6. Position control optimization of aerodynamic brake device for high-speed trains

    Science.gov (United States)

    Zuo, Jianyong; Luo, Zhuojun; Chen, Zhongkai

    2014-03-01

    The aerodynamic braking is a clean and non-adhesion braking, and can be used to provide extra braking force during high-speed emergency braking. The research of aerodynamic braking has attracted more and more attentions in recent years. However, most researchers in this field focus on aerodynamic effects and seldom on issues of position control of the aerodynamic braking board. The purpose of this paper is to explore position control optimization of the braking board in an aerodynamic braking prototype. The mathematical models of the hydraulic drive unit in the aerodynamic braking system are analyzed in detail, and the simulation models are established. Three control functions—constant, linear, and quadratic—are explored. Two kinds of criteria, including the position steady-state error and the acceleration of the piston rod, are used to evaluate system performance. Simulation results show that the position steady state-error is reduced from around 12-2 mm by applying a linear instead of a constant function, while the acceleration is reduced from 25.71-3.70 m/s2 with a quadratic control function. Use of the quadratic control function is shown to improve system performance. Experimental results obtained by measuring the position response of the piston rod on a test-bench also suggest a reduced position error and smooth movement of the piston rod. This implies that the acceleration is smaller when using the quadratic function, thus verifying the effectiveness of control schemes to improve to system performance. This paper proposes an effective and easily implemented control scheme that improves the position response of hydraulic cylinders during position control.

  7. Plugging Braking of Two-PMSM Drive in Subway Applications with Fault-Tolerant Operation

    Directory of Open Access Journals (Sweden)

    Adel A. obed

    2016-06-01

    Full Text Available The Permanent Magnet Synchronous Motor (PMSM is commonly used as traction motors in the electric traction applications such as in subway train. The subway train is better transport vehicle due to its advantages of security, economic, health and friendly with nature. Braking is defined as removal of the kinetic energy stored in moving parts of machine. The plugging braking is the best braking offered and has the shortest time to stop. The subway train is a heavy machine and has a very high moment of inertia requiring a high braking torque to stop. The plugging braking is an effective method to provide a fast stop to the train. In this paper plugging braking system of the PMSM used in the subway train in normal and fault-tolerant operation is made. The model of the PMSM, three-phase Voltage Source Inverter (VSI controlled using Space Vector Pulse Width Modulation technique (SVPWM, Field Oriented Control method (FOC for independent control of two identical PMSMs and fault-tolerant operation is presented. Simulink model of the plugging braking system of PMSM in normal and fault tolerant operation is proposed using Matlab/Simulink software. Simulation results for different cases are given.

  8. 汽车ABS试验台传感器与系统灵敏度的确定%Determination of Sensors and System Sensitivity in the Motor Vehicle ABS Test-bed

    Institute of Scientific and Technical Information of China (English)

    孙仁云

    2001-01-01

    According to the test parameters requirement on an Anti-lock Brake System (ABS) test-bed of the motor vehicle,some sensors are selected and arranged in its test system.It is elementary task to select sensors optimally in this research.In this paper,a selection and computing method of five sensors in the test-bed are expounded.The test system sensitivities are made sure on the basis of the sensors connected with instruments.The result of a debug has shown that the method is reasonable.%依据汽车防抱死制动装置(简称ABS)试验台测试参数的要求,在测试系统中需要布置和选择相应的测量传感器,合理选择测量传感器是该试验台研制过程中的一项基本任务。详细阐述试验台使用的五个传感器的选择和计算方法,并根据传感器后接的二次仪表确定测试系统灵敏度。从调试结果可以看出,上述方法是合理的。

  9. Development and Analysis of Train Brake Curve Calculation Methods with Complex Simulation

    Directory of Open Access Journals (Sweden)

    Bela Vincze

    2006-01-01

    Full Text Available This paper describes an efficient method using simulation for developing and analyzing train brake curve calculation methods for the on-board computer of the ETCS system. An application example with actual measurements is also presented.

  10. Analysis and Design of Circular Plate MR Fluids Brake

    Institute of Scientific and Technical Information of China (English)

    Yang Yan; Lin Chang-Hua; Li Hui; Zhou Jing

    2004-01-01

    A magnetorheological (MR) fluids brake is a device to achieve brake by shear force of MR fluids. A MR rotary brake has the property that its braking torque changes quickly in response to an external magnetic field. In this study, the design method of the circular plate MR fluids brake is investigated theoretically. The equation of the torque transmitted by the MR fluids in the brake is derived to provide the theoretical foundation in the design of the brake. Based on this equation, after mathematically manipulated, the calculations of the volume, thickness and width of the MR fluids within the circular plate MR fluids brake are yield.

  11. Research on Heat-Mechanical Coupling of Ventilated Disc Brakes under the Condition of Emergency Braking

    Science.gov (United States)

    Tan, Xuelong; Zhang, Jian; Tang, Wenxian; Zhang, Yang

    Taking the ventilated disc brake in some company as research object, and using UG to build 3D models of brake disc and pad, and making use of ABAQUS/Standard to set up two parts' finite element model, via the decelerated motion of actual simulation brake disc, which gets ventilated disc brake in the case of emergency breaking in time and space distribution of conditions of temperature and stress field, summarizes the distribution of temperature field and stress field, proves complex coupling between temperature, stress, and supplies the direct basis for brake's fatigue life analysis.

  12. Braking indices of pulsars obtained in the presence of an effective force

    CERN Document Server

    Magalhaes, N S; Frajuca, C

    2016-01-01

    Braking indices of pulsars present a scientific challenge as their theoretical calculation is still an open problem. In this paper we report results of a study regarding such calculation which adapts the canonical model (which admits that pulsars are rotating magnetic dipoles) basically by introducing a compensating component in the energy conservation equation of the system. This component would correspond to an effective force that varies with the first power of the tangential velocity of the pulsar's crust. We test the proposed model using data available and predict braking indices values for different stars. We comment on the high braking index recently measured of the pulsar J1640-4631.

  13. Impact of Brake Pad Structure on Temperature and Stress Fields of Brake Disc

    Directory of Open Access Journals (Sweden)

    Guoshun Wang

    2013-01-01

    Full Text Available Utilizing ABAQUS finite element software, the study established the relationship between a brake pad structure and distributions of temperature and thermal stress on brake disc. By introducing radial structure factor and circular structure factor concepts, the research characterized the effect of friction block radial and circumferential arrangement on temperature field of the brake disc. A method was proposed for improving heat flow distribution of the brake disc through optimizing the position of the friction block of the brake pad. Structure optimization was conducted on brake pads composed of 5 or 7 circular friction blocks. The result shows that, with the same overall contact area of friction pair, an appropriate brake pad structure can make the friction energy distribute evenly and therefore lowers peak temperature and stress of the brake disc. Compared with a brake pad of 7 friction blocks, an optimized brake pad of 5 friction blocks lowered the peak temperature of the corresponding brake disc by 4.9% and reduced the highest stress by 10.7%.

  14. Effect of surface texture and working gap on the braking performance of the magnetorheological fluid brake

    Science.gov (United States)

    Wang, Na; Li, Dong Heng; Li Song, Wan; Chao Xiu, Shi; Zhi Meng, Xiang

    2016-10-01

    In this paper, the effect of the surface textures of braking disc on the braking performance is experimentally investigated under the conditions of different working gaps and applied currents. For this purpose, a new configuration of magnetorheological fluid brake (MRB) with adjustable working gap is developed to improve the manufacturing accuracy and cost, and to reduce the problem of replacing the braking disc. In addition, the braking discs with three types of surface texture are designed and machined. Based on the test bed developed for the proposed MRB, a series of experiments are carried out on the manufactured prototype and the results are presented to obtain the relationship among the surface texture of the braking disc, applied current, working gap and the braking performance. The results show that the braking torque is significantly influenced by the working gap and surface texture of the braking disc, and the maximum braking torque is obtained on the conditions of 0.25 mm working gap and the braking disc with square surface texture.

  15. Braking index of isolated pulsars

    Science.gov (United States)

    Hamil, O.; Stone, J. R.; Urbanec, M.; Urbancová, G.

    2015-03-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities Ω , and their time derivatives that show unambiguously that the pulsars are slowing down. Although the exact mechanism of the spin-down is a question of detailed debate, the commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. Other processes, including the emission of gravitational radiation, and of relativistic particles (pulsar wind), are also being considered. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of Ω . This relation leads to the power law Ω ˙ =-K Ωn where n is called the braking index. The MDR model predicts n exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of n , individually accurate to a few percent or better, in the range 1 braking index within the MDR model. Four microscopic equations of state are employed as input to two different computational codes that solve Einstein's equations numerically, either exactly or using the perturbative Hartle-Thorne method, to calculate the

  16. Electronic Brake-Force Distribution Control Methods of ABS-Equipped Vehicles During Cornering Braking

    Institute of Scientific and Technical Information of China (English)

    WANG Guo-ye; LIU Zhao-du; MA Yue-feng; QI Zhi-quan

    2007-01-01

    Based on the dynamics of ABS-equipped vehicles during cornering braking,the electronic brakeforce distribution (EBD) control methods of ABS-equipped vehicles during cornering braking are proposed.According to the dynamics and the tire model under tire adhesion limit,the stability acceptance criteria of vehicles during cornering braking are proposed.According to the stability acceptance criteria and the ABS control,the EBD control methods of ABS-equipped vehicles during cornering braking are implemented by adjusting the threshold values of tires slip independently.The vehicle states during cornering braking at two typical initial velocities of the vehicle are analyzed by the EBD control methods,whose results indicate the EBD control methods can improve the braking performances of the vehicle during cornering braking comparing with the ABS control.

  17. Tribomaterial factors in space mechanism brake performance

    Science.gov (United States)

    Hawthorne, H. M.

    1990-01-01

    The asbestos/phenolic pads of Shuttle Remote Manipulator System (SRMS) brakes are unsuitable for use in long life space mechanisms because their friction decreases on extended sliding in high vacuum. Dehydration of the material and accumulation of wear debris in the conforming interface of this tribosystem induces the permanent friction changes. Other polymer and some ceramic based materials exhibit similar frictional torque behavior due to the development of minimal contact patches by the interfacial debris. In contrast, high friction occurs when other ceramics form many small contacts throughout fine debris beds. Generating this latter interfacial structure during run-in ensures that the in-vacuo friction remains stable thereafter. Such materials with low wear rates are potential candidates for friction elements in SSRMS and similar mechanisms.

  18. Thermal measurement of brake pad lining surfaces during the braking process

    Science.gov (United States)

    Piątkowski, Tadeusz; Polakowski, Henryk; Kastek, Mariusz; Baranowski, Pawel; Damaziak, Krzysztof; Małachowski, Jerzy; Mazurkiewicz, Łukasz

    2012-06-01

    This paper presents the test campaign concept and definition and the analysis of the recorded measurements. One of the most important systems in cars and trucks are brakes. The braking temperature on a lining surface can rise above 500°C. This shows how linings requirements are so strict and, what is more, continuously rising. Besides experimental tests, very supportive method for investigating processes which occur on the brake pad linings are numerical analyses. Experimental tests were conducted on the test machine called IL-68. The main component of IL-68 is so called frictional unit, which consists of: rotational head, which convey a shaft torque and where counter samples are placed and translational head, where samples of coatings are placed and pressed against counter samples. Due to the high rotational speeds and thus the rapid changes in temperature field, the infrared camera was used for testing. The paper presents results of analysis registered thermograms during the tests with different conditions. Furthermore, based on this testing machine, the numerical model was developed. In order to avoid resource demanding analyses only the frictional unit (described above) was taken into consideration. Firstly the geometrical model was performed thanks to CAD techniques, which in the next stage was a base for developing the finite element model. Material properties and boundary conditions exactly correspond to experimental tests. Computations were performed using a dynamic LS-Dyna code where heat generation was estimated assuming full (100%) conversion of mechanical work done by friction forces. Paper presents the results of dynamic thermomechanical analysis too and these results were compared with laboratory tests.

  19. Marble Waste Using Produced of Automotive Brake Pad of Friction Coefficient Different Pad Brake Pads With Comprasion

    Directory of Open Access Journals (Sweden)

    Mustafa Timur

    2013-01-01

    Full Text Available Brake linings used in automotive disks are usually composed of various components. Expected properties from a brake lining are appropriate standard value of wear resist, friction coefficient. Brake lining extremely warms up during braking due to friction. The braking performance of brake lining changes and braking lining is subject to mechanical deformation due to excessive temperature. In this study, it is aimed to revaluate the waste of marble dust in marble processing in Turkey. For this purpose, marble wastes are grinded to produce marble dust. The brake lining, which has new formulation, is produced by using various additive materials. The friction performances of the brake pads produced were compared with those of other firms and the results were show in graphics. Therefore, the effect of marble dust on braking performance is investigated. It is observed that a favorable result in braking performance is obtained using of marble dust.

  20. What brakes the Crab pulsar?

    CERN Document Server

    Čadež, A; Barbieri, C; Calvani, M; Naletto, G; Barbieri, M; Ponikvar, D

    2015-01-01

    Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. From our analysis, we demonstrate that the power law index undergoes "inst...

  1. Frictional Performance and Temperature Rise of a Mining Nonasbestos Brake Material during Emergency Braking

    Directory of Open Access Journals (Sweden)

    Jiusheng Bao

    2015-01-01

    Full Text Available By simulating emergency braking conditions of mine hoisters, tribological experiments of a mining nonasbestos brake material sliding on E355CC steel friction disc investigated a pad-on-disc friction tester. It is shown that, under combined influence of braking velocity and pressure, the lubricating film and micro-convex-apices on wear surface would have complex physicochemical reactions which make the instant friction coefficient rise gradually while the instant surface temperature rises first and then falls. With the antifriction effect from lubricating film and the desquamating of composite materials, the mean friction coefficient decreases first, then rises, and decreases again with the increasing of initial braking velocity. And with the existence of micro-convex-apices and variation from increment ratio of load and actual contacting area, it rises first and then falls with the increasing of braking pressure. However, the mean surface temperature rises obviously with the increasing of both initial braking velocity and braking pressure for growth of transformed kinetic energy. It is considered that the friction coefficient cannot be considered as a constant when designing brake devices for mine hoisters. And special attention should be paid to the serious influence of surface temperature on tribological performance of brake material during emergency braking.

  2. Effects of Magnetic Braking and Tidal Friction on Hot Jupiters

    CERN Document Server

    Barker, A J

    2009-01-01

    Tidal friction is thought to be important in determining the long-term spin-orbit evolution of short-period extrasolar planetary systems. Using a simple model of the orbit-averaged effects of tidal friction Eggleton, Kiseleva & Hut (1998), we analyse the effects of the inclusion of stellar magnetic braking on the evolution of such systems. A phase-plane analysis of a simplified system of equations, including only the stellar tide together with a model of the braking torque proposed by Verbunt & Zwaan (1981), is presented. The inclusion of stellar magnetic braking is found to be extremely important in determining the secular evolution of such systems, and its neglect results in a very different orbital history. We then show the results of numerical integrations of the full tidal evolution equations, using the misaligned spin and orbit of the XO-3 system as an example, to study the accuracy of simple timescale estimates of tidal evolution. We find that it is essential to consider coupled evolution of th...

  3. An analysis of the friction mechanism on brake gear of railway rolling stock

    Directory of Open Access Journals (Sweden)

    J. H. Barnard

    1985-03-01

    Full Text Available Friction energy dissipation at an interface involves a wide range of interdisciplinary concepts. As the demand for higher operating speeds increased, the limitations of cast iron as the traditional friction material for rail transport brakes became more apparent. Only through an intensive analysis of the interfacial interaction between the brake block and brake path could the problems encountered with other promising friction materials be solved. The article deals with the difficulties pertaining to the early composite materials, and indicates how these were overcome by the understanding and implementation of new techniques not previously associated with conventional systems connected with railway braking. Two composite materials, that is 840/N for locomotives and freight wagons where mass oriented momentum dominates, and high friction composite 655/C for passenger vehicles with a predominantly speed-oriented momentum, are presently used.

  4. An Intelligent Regenerative Braking Strategy for Electric Vehicles

    OpenAIRE

    Zhibin Song; Weimin Li; Guoqing Xu; Kun Xu

    2011-01-01

    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 ex...

  5. An Intelligent Regenerative Braking Strategy for Electric Vehicles

    OpenAIRE

    Guoqing Xu; Weimin Li; Kun Xu; Zhibin Song

    2011-01-01

    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 ex...

  6. Test Study on Assistant Braking Performance of Bus/Coach%客车辅助制动性能试验研究

    Institute of Scientific and Technical Information of China (English)

    周科

    2013-01-01

    The classification, function and principle of the assistant braking system of some coach are introduced. Through doing deceleration test to the assistant braking system of a coach based on the relative standard, the test data show that the braking performance of the retarder is superior to the engine braking system and the engine exhaust braking system, and the engine braking system or the engine exhaust braking system combined with the retarder can improve the braking performance of the coach braking in the high speed condition.%介绍客车辅助制动系统的分类、作用及原理。以某型客车为例,依据相关标准,采用减速度测定试验方法来测试样车的辅助制动性能。结果表明,缓速器制动的制动效能要优于发动机制动和发动机排气制动;采用发动机制动、发动机排气制动与缓速器联合工作的方式,能够有效地改善高速行车时的制动效能。

  7. Hunting Plan Morgan Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan provides guidelines for administration of hunting activity and for development, maintenance, and enforcement of regulations and guidelines on Morgan Brake...

  8. A smart accelerometer-based braking system for baby strollers%一种基于加速度传感器的婴儿车智能刹车系统研究

    Institute of Scientific and Technical Information of China (English)

    李廷志; 王俭

    2012-01-01

    This paper presents a smart braking system for the baby stroller by using the MEMS accelerometer. The system has a micro controller as its core and relies on solar energy as its power supply. Based on the message sent out by the accelerometer, the control system can avoid the stroller from slipping away on the slope due to guardians' neglect. The experiment results of the prototype show that the design principle of the system is correct, responsive and reliable.%提出一种利用MEMS加速度传感器技术的坡度敏感的婴儿车智能刹车系统方案。系统以微控制器为核心,依靠太阳能提供动力,能够根据传感器给出的路面坡度情况,自动采取刹车措施以避免婴儿车在坡度路面因监护人疏忽而滑离的危险。样机的试验结果表明,坡度敏感的智能刹车系统原理正确、反应灵敏、运行可靠。

  9. Experiment and Analysis on ASR Braking Interference Function for ABS/ASR System%ABS/ASR集成系统中ASR制动干预试验测试分析

    Institute of Scientific and Technical Information of China (English)

    王仁广; 崔海峰; 刘昭度

    2009-01-01

    Based on hydraulic ABS system of JETTA-GTX car,it develops a electric control system integrated with ABS/ASR.This system can desl with the road tests conducted to check ASR function of ABS/ASR.All tests are completed on even-dry road and low friction coefficient road surface which simulated the splitμ road surface.It uses ASR and non-ASR conditions respectively to run acceleration and starting acceleration modes.The method is adopted to regulate braking pressure preciously during ASR operation.Test results show that the system can reach the design target satisfactorily.%基于JETTA-GTX轿车液压ABS系统,在保持原车ABS功能的前提下,开发出ABS/ASR集成控制系统.为了检验所开发的集成控制器中ASR系统控制效果,在干燥的沥青路面和模拟低摩擦系数的对开路面上,针对行驶加速和起步加速2种典型工况进行了有ASR制动干预控制和无ASR制动干预控制的试验测试.通过对试验结果进行对比分析表明,所开发的ABS/ASR集成控制系统达到了设计目标.

  10. Method and apparatus for wind turbine braking

    Science.gov (United States)

    Barbu, Corneliu; Teichmann, Ralph; Avagliano, Aaron; Kammer, Leonardo Cesar; Pierce, Kirk Gee; Pesetsky, David Samuel; Gauchel, Peter

    2009-02-10

    A method for braking a wind turbine including at least one rotor blade coupled to a rotor. The method includes selectively controlling an angle of pitch of the at least one rotor blade with respect to a wind direction based on a design parameter of a component of the wind turbine to facilitate reducing a force induced into the wind turbine component as a result of braking.

  11. A simple calibration method for mechanically braked cycle ergometers.

    Science.gov (United States)

    Van Praagh, E; Bedu, M; Roddier, P; Coudert, J

    1992-01-01

    The calibration of cycle ergometers should be checked regularly. Some studies have shown calibration errors of more than 40%. A simple, inexpensive calibrating method for mechanically braked cycle ergometers was developed and tried out on a new type of ergocycle. The cycle ergometer was elevated and the crank replaced by a pulley fitted to the shaft. The crank speed (rpm) increased linearly as a function of time when different masses were applied on the pulley. For a given braking force on the cycle ergometer, different accelerations corresponding to the increased pulley forces could be measured. When extrapolating for zero acceleration, it was possible to determine a "limit-force" which allowed the system to be in equilibrium. Additional force creates motion. The same experiments were repeated with increasing braking forces. Using the differently sized gear sprockets of the transmission system, it was possible to calculate the actual force, including all the resistances. The actual force found by the calibrating method was then compared with the indicated force proposed by the manufacturer. With increasing forces, the relative errors decreased from 9.6 to 2.9%. The cycle ergometer calibrated by this technique meets the standards recommended in exercise physiology. PMID:1544728

  12. Constraining the Braking Indices of Magnetars

    CERN Document Server

    Gao, Z F; Wang, N; Yuan, J P; Peng, Q H; Du, Y J

    2015-01-01

    Due to the lack of long term pulsed emission in quiescence and the strong timing noise, it is impossible to directly measure the braking index $n$ of a magnetar. Based on the estimated ages of their potentially associated supernova remnants (SNRs), we estimate the values of $n$ of nine magnetars with SNRs, and find that they cluster in a range of $1\\sim$41. Six magnetars have smaller braking indices of $13$ for other three magnetars are attributed to the decay of external braking torque, which might be caused by magnetic field decay. We estimate the possible wind luminosities for the magnetars with $13$ within the updated magneto-thermal evolution models. We point out that there could be some connections between the magnetar's anti-glitch event and its braking index, and the magnitude of $n$ should be taken into account when explaining the event. Although the constrained range of the magnetars' braking indices is tentative, our method provides an effective way to constrain the magnetars' braking indices if th...

  13. Human-simulated intelligent control of train braking response of bridge with MRB

    Science.gov (United States)

    Li, Rui; Zhou, Hongli; Wu, Yueyuan; Wang, Xiaojie

    2016-04-01

    The urgent train braking could bring structural response menace to the bridge under passive control. Based on the analysis of breaking dynamics of a train-bridge vibration system, a magnetorheological elastomeric bearing (MRB) whose mechanical parameters are adjustable is designed, tested and modeled. A finite element method (FEM) is carried out to model and optimize a full scale vibration isolation system for railway bridge based on MRB. According to the model above, we also consider the effect of different braking stop positions on the vibration isolation system and classify the bridge longitudinal vibration characteristics into several cases. Because the train-bridge vibration isolation system has multiple vibration states and strongly coupling with nonlinear characteristics, a human-simulated intelligent control (HSIC) algorithm for isolating the bridge vibration under the impact of train braking is proposed, in which the peak shear force of pier top, the displacement of beam and the acceleration of beam are chosen as control goals. The simulation of longitudinal vibration control system under the condition of train braking is achieved by MATLAB. The results indicate that different braking stop positions significantly affect the vibration isolation system and the structural response is the most drastic when the train stops at the third cross-span. With the proposed HSIC smart isolation system, the displacement of bridge beam and peak shear force of pier top is reduced by 53.8% and 34.4%, respectively. Moreover, the acceleration of bridge beam is effectively controlled within limited range.

  14. A global strategy based on experiments and simulations for squeal prediction on industrial railway brakes

    Science.gov (United States)

    Sinou, J.-J.; Loyer, A.; Chiello, O.; Mogenier, G.; Lorang, X.; Cocheteux, F.; Bellaj, S.

    2013-09-01

    This paper presents an overview of recent experimental and numerical investigations on industrial railway brakes. The goal of the present study is to discuss the relevance of the mechanical modeling strategy for squeal prediction. Specific experimental set-ups based on transient and controlled braking tests are designed for this purpose. Measurements are performed on it to investigate the dynamic behavior of TGV squeal noise and its squeal characterization through experiments. It will be demonstrated that it is possible to build consistent and efficient finite element models to simulate squeal events in TGV brake systems. The numerical strategy will be presented, including not only the modeling of the TGV brake system and the stability analysis, but also the transient nonlinear dynamic and computational process based on efficient reduced basis. This complete numerical strategy allows us to perform relevance squeal prediction on industrial railway brakes. This study comes within the scope of a research program AcouFren that is supported by ADEME (Agence De l'Environnement et de la Maîtrise de l'Energie) concerning the reduction of the squeal noise generated by high power railway disc brakes. experiments with an evolution of the rotational speed of the disc: these tests are called "transient braking tests" and correspond to real braking tests, experiments with a controlled steady rotational speed (i.e. dynamic fluctuations in rotational speed are not significant): these tests are called "controlled braking tests". In the present study, the Continuous Wavelet Transform (CWT) [20] is used to study the time-history responses of the TGV brake system. So, a brief basic theory of the wavelet analysis that transforms a signal into wavelets that are well localized both in frequency and time is presented in this part of the paper. Considering a function f(t), the associated Continuous Wavelet Transform (CWT) corresponds to a wavelet transform given by W(a,b

  15. Evaluation of Wear in Aftermarket Brake Pads for Enhancing Braking Performance in a Passenger Vehicle

    Directory of Open Access Journals (Sweden)

    Mohd Zaki Bahrom

    2016-08-01

    Full Text Available Nowadays, due to the high demands from the independence automotive service centers; there are many aftermarket brake pads available at spare parts shops and sold at reasonable prices. Several types of brake pads are available in the market such as semi-metallic and Non-Asbestos brake pads. The purpose of this study is to evaluate the wear of after-market brake pad performance under the normal driving conditions (highway and non-highway. Three types of aftermarket brake pads that mainly used and sold by independent service shop were selected in this study.  The data of the wear in thicknesses losses and weight percentage losses were recorded. The results show that brake pad of non- Asbestos Organic type gives the highest wear loss and create a lot of dust. For semi-metallic brake pad type, the result shows the lowest mass loss. Therefore, it is important to select the suitable type of after-market brake pads in order to get balance between cost and quality.

  16. The Role of Solid Lubricants for Brake Friction Materials

    Directory of Open Access Journals (Sweden)

    Werner Österle

    2016-02-01

    Full Text Available This review article comprises of three parts. Firstly, reports of brake manufacturers on the beneficial impact of solid lubricants for pad formulations are surveyed. Secondly, since tribofilms were identified to play a crucial role in friction stabilization and wear reduction, the knowledge about tribofilm structures formed during automotive braking was reviewed comprehensively. Finally, a model for simulating the sliding behavior of tribofilms is suggested and a review on modelling efforts with different model structures related to real tribofilms will be presented. Although the variety of friction composites involved in commercial brake systems is very broad, striking similarities were observed in respect to tribofilm nanostructures. Thus, a generalization of the tribofilm nanostructure is suggested and prerequisites for smooth sliding performance and minimal wear rates have been identified. A minimum of 13 vol % of soft inclusions embedded in an iron oxide based tribofilm is crucial for obtaining the desired properties. As long as the solid lubricants or their reaction products are softer than magnetite, the main constituent of the tribofilm, the model predicts smooth sliding and minimum wear.

  17. On the safety of braking mine up-haulage devices

    Energy Technology Data Exchange (ETDEWEB)

    Murzin, V.A.; Samusia, V.I.

    1982-01-01

    Experiments conducted on several mine up-haulage devices to analyze breakdowns due to the operator who quickly turned on the brake showed that sudden braking may really invoke maximum brake application on the machine winding much earlier than preventive braking and may lead to shutdown. It was concluded that in the Safety Regulations or Engineering Regulations that use of the handbrake should be more clearly outlined to preclude breakdown. One method of prevention is to develop and use a diagram showing build-up and magnitude of the braking moment when using the manual brake.

  18. Thediscusses of the braking system of the locomotive signal data collection and processing mode%机车制动系统信号的采集和处理方式探讨

    Institute of Scientific and Technical Information of China (English)

    周鹏; 刘泉

    2013-01-01

      随着我国铁路事业的高速发展,对机车的安全性要求也越来越高。有效的数据采集是确保机车安全可靠运行的保障之一,同时也是机车故障诊断系统的重要组成部分。准确的采集机车运行时的状态信息,对机车的安全运行至关重要。简要探讨了机车制动系统信号的数据采集和处理方式。%with the rapid development of railroad ,It is more and more high security requirement to locomotive .The ffective data collec-tion is to ensure the security of the safe and reliable operation of the locomotive ,it is also an important part of the locomotive fault diag-nosis diagnosis system .Locomotive running state information of accurate collecting for the safe operation of the locomotive is very impor-tant .The paper discusses the braking system of the locomotive signal data collection and processing mode .

  19. Braking Index of Isolated Pulsars

    CERN Document Server

    Hamil, Oliver Q; Urbanec, Martin; Urbancova, Gabriela

    2016-01-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities $\\Omega$, and their time derivatives that show unambiguously that the pulsars are slowing down. The commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of $\\Omega$. This relation leads to the power law $\\dot{\\Omega}$ = -K $\\Omega^{\\rm n}$ where $n$ is called the braking index. The MDR model predicts $n$ exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of $n$, individually accurate to a few percent or better, in the range 1$ <$ n $ < $ 2.8, which is consistently less than the predictions of the MDR model. In spite of an extensive investigation of various modifications of the MDR model, no satisfactory explanation of observation has been found yet. The aim of this work is t...

  20. Detection of braking intention in diverse situations during simulated driving based on EEG feature combination

    Science.gov (United States)

    Kim, Il-Hwa; Kim, Jeong-Woo; Haufe, Stefan; Lee, Seong-Whan

    2015-02-01

    Objective. We developed a simulated driving environment for studying neural correlates of emergency braking in diversified driving situations. We further investigated to what extent these neural correlates can be used to detect a participant's braking intention prior to the behavioral response. Approach. We measured electroencephalographic (EEG) and electromyographic signals during simulated driving. Fifteen participants drove a virtual vehicle and were exposed to several kinds of traffic situations in a simulator system, while EEG signals were measured. After that, we extracted characteristic features to categorize whether the driver intended to brake or not. Main results. Our system shows excellent detection performance in a broad range of possible emergency situations. In particular, we were able to distinguish three different kinds of emergency situations (sudden stop of a preceding vehicle, sudden cutting-in of a vehicle from the side and unexpected appearance of a pedestrian) from non-emergency (soft) braking situations, as well as from situations in which no braking was required, but the sensory stimulation was similar to stimulations inducing an emergency situation (e.g., the sudden stop of a vehicle on a neighboring lane). Significance. We proposed a novel feature combination comprising movement-related potentials such as the readiness potential, event-related desynchronization features besides the event-related potentials (ERP) features used in a previous study. The performance of predicting braking intention based on our proposed feature combination was superior compared to using only ERP features. Our study suggests that emergency situations are characterized by specific neural patterns of sensory perception and processing, as well as motor preparation and execution, which can be utilized by neurotechnology based braking assistance systems.

  1. Control strategy for electro-mechanical braking based on curves of ECE regulations and ideal braking force%基于ECE法规和Ⅰ曲线的机电复合制动控制策略

    Institute of Scientific and Technical Information of China (English)

    刘丽君; 姬芬竹; 杨世春; 徐斌

    2013-01-01

    具有再生制动功能的电动汽车制动系统与传统燃油汽车的摩擦制动系统不同,在回收部分制动能量的同时其制动稳定性会发生变化.在保证安全制动距离的前提下,制动能量回收率的提高受到制动稳定性的制约和限制.针对电制动和常规摩擦制动组成的机电复合制动系统,建立了电制动力、电制动力矩和电池充电功率计算模型.考虑到电机转矩特性和电池充电功率限制,以最大化回收制动能量为目标,设计3种不同的机电复合制动控制策略.通过在ADVISOR软件中建立嵌入式仿真模块对制动能量回收率、电池荷电状态和纯电动模式的续驶里程进行了仿真计算和分析.计算结果表明:Ⅰ曲线和ECE(Economic Commissionof Europe safety regulations)法规边界线都不是理想的制动力分配曲线,所提出的制动力分配曲线OABCD综合性能较好,制动能量回收率达到59.56%,且一个循环的荷电状态变化很小,仅降低了4.29%.实车试验表明能量回收能够提高续驶里程.%The braking system of electric vehicle with regenerative braking is different from friction braking system of conventional fuel vehicle. Regenerative braking system makes braking stability of electric vehicles change when it recovers braking energy of vehicles. The improvement of braking energy recovery ration was restricted by the braking stability under the precondition of safe braking distance. Aiming at the electromechanical hybrid braking system composed of electric braking and conventional friction braking, the calculation models of electric braking force, electric braking torque and battery charging power were established. In view of the motor torque characteristics and battery charging power limit, three kinds of control strategies for e-lectro-mechanical hybrid braking were designed for recovering the maximal braking energy. The baking energy recovery ration, state of charge and driving range in

  2. Research of Pneumatic Braking Relay Valve for Urban Bus Performance Test System%公交客车气制动继动阀性能测试系统研究

    Institute of Scientific and Technical Information of China (English)

    易北华; 杨春生; 陈正龙

    2013-01-01

    A test system was designed under the test method of relay valve performance which was proposed based on the working principle and function of relay valve in the automobile pneumatic braking system. The system consisted mainly of industrial computer, data acquisition system, pneumatic system, exhaust system, sensors and control circuit. When the pressure regulating range was 0. 05-1. 5MPa and pressure measuring range was 0-1. 2MPa, the performance test results of relay valve showed that the pressure measuring accuracy had reached 0. 25 % , the system had high measurement precision and satisfied the design request.%通过对继动阀在汽车气制动系统的作用,以及其在气制动系统中工作原理的分析,提出了继动阀的性能测试方法,设计了继动阀的测试系统.该系统主要包括工控机、数据采集系统、气动系统、排气系统、传感器、控制电路.当气压调节范围为0.05~1.5MPa,气压测量范围为0~ 1.2MPa时,继动阀性能测试结果表明,气压测量精度可以达到0.25%,系统测试精度高,满足设计要求.

  3. Weight reduction of a standard brake drum: A design approach

    Directory of Open Access Journals (Sweden)

    D. Rambabu

    2014-03-01

    Full Text Available A Brake drum is specialized brake that uses the concept of friction to decelerate the vehicle speed. The deceleration is achieved by the assistance of the friction generated by a set of brake shoes or pad, when operator presses against a rotating brake drum. The material generally preferred for making the brake drum is grey cast iron or vermicular cast iron. The drum brake is highly efficient for hand brake and service brake applications. During the operation of drum brake excessive heating of brake drum may occur. This excessive heating occurs due to repeated or frequent contact of the brake shoes against the drum. This causes the drum to crack, oversize, extreme wear, out of round drums and also leads to vibration which while braking will leads to reduced brake drum life and braking efficiency. The Un-laden weight of the vehicle will result in increased fuel consumption, reduced payload and ride handling characteristics. The objective of the paper is to improve the thermal characteristics by incorporating fins in the brake drum and to reduce the un-laden weight of the vehicle by changing the rib thickness, wall thickness and base flange thickness. The design is done by using 3D CAD Modelling software and Hexahedral finite element model prepared by using CAE pre-processing software and Stiffness analysis. Design iterations are carried out by using Linear/Non-linear Finite Element Solvers, Stress Displacement and Temperature is post-processed for design validation. Optimized design solution obtained based on the comparison study between the iteration with rib thickness 75 mm, star shaped removal and wall thickness 17 mm has been chosen. 1.8Kg of weight is being reduced from the brake drum including fins.   Keywords: Drum Brake, 3D CAD Modelling, Para Metric Matrix, Structural Analysis, Fins.

  4. A new strategy for transient stability using augmented generator control and local dynamic braking

    Energy Technology Data Exchange (ETDEWEB)

    Dorsey, J.; Jiang, H.; Habetler, T. [Georgia Inst. of Tech., Atlanta, GA (United States); Qu, Z. [University of Central Florida, Orlando, FL (United States)

    1994-12-31

    A decentralized automatic control strategy for significantly improving the transient stability of a large power system is introduced. The strategy combines local dynamic braking and a straightforward augmentation of the existing turbine / governor control system that uses only local feedback. The brake resistor, which employs thick film, metal oxide technology, has no inductance and is of very low resistance, allowing its use during fault to show a generator`s acceleration. Simulation results using the 39 Bus New England system show that the strategy dramatically increases the global stability of a power system. (author) 15 refs., 7 figs., 1 tab.

  5. 76 FR 49533 - Spyker Automobielen B.V.; Receipt of Application for Temporary Exemption from FMVSS No. 126

    Science.gov (United States)

    2011-08-10

    ... the driver in maintaining vehicle control. An anti-lock brake system (ABS) is a prerequisite for an ESC system because ESC uses many of the same components as ABS. Thus, the cost of complying with FMVSS... had to develop a new ABS system. In an effort to achieve compliance with FMVSS No. 126, Spyker...

  6. On the potential of uncertainty analysis for prediction of brake squeal propensity

    Science.gov (United States)

    Zhang, Zhi; Oberst, Sebastian; Lai, Joseph C. S.

    2016-09-01

    Brake squeal is a source of significant warranty-related claims for automotive manufacturers because it is annoying and is often perceived by customers as a safety concern. A brake squeal analysis is complex due to changing environmental and operating conditions, high sensitivity to manufacturing and assembly tolerances as well as the not so well understood role of nonlinearities. Although brake squeal is essentially a nonlinear problem, the standard analysis tool in industry is the linear complex eigenvalue analysis (CEA) which may under-predict or over-predict the number of unstable vibration modes. A nonlinear instability analysis is more predictive than CEA but is still computationally too expensive to be used routinely in industry for a full brake finite element model. Also, although the net work analysis of a linearised brake system has shown potential in predicting the origin of brake squeal, it has not been extensively used. In this study, the net work of an analytical viscously damped self-excited 4-dof friction oscillator with cubic contact force nonlinearity is compared with the instability prediction using the CEA and a nonlinear instability analysis. Results show that both the net work analysis and CEA under-predict the instability because of their inability to detect the sub-critical Hopf bifurcation. Then, the uncertainty analysis is applied to examine if it can improve instability prediction of a nonlinear system using linear methods and its limitations. By applying a variance-based global sensitivity analysis to parameters of the oscillator, suitable candidates for an uncertainty analysis are identified. Results of uncertainty analyses by applying polynomial chaos expansions to net work and CEA correlate well with those of the nonlinear analysis, hence demonstrating the potential of an uncertainty analysis in improving the prediction of brake squeal propensity using a linear method.

  7. Influence of Friction Drive Lift Gears Construction on the Length of Braking Distance

    Institute of Scientific and Technical Information of China (English)

    LONKWIC Poul

    2015-01-01

    The friction drive elevators the influence of the braking distance has very high significance to meet certain safety regulations and comfort. During the emergency braking the delay for the system a frame and a cabin should be within the range from 0.2 to 9.81 m/s2. However, there are no specialist literatures regarding the issues connected with emergency braking of elevating devices either. The results of the own empirical research work are presented regarding the influence of design changes on the working parameters of the friction drive elevator gears. ASG100, KB160, PP16, PR2000UD and CHP2000 types of safety progressive gears are analyzed. ASG100, KB160, PP16, PR2000UD type progressive gears are already produced by European manufacturers. CHP2000 type gears are established as the alternative option for the already existing solutions. The unique cam system has been used in the CHP 2000 gears. The cam leverage gives the chance to unblock, in a very easy way, the clamed gears after braking. Thus, it is a key aspect to perform laboratory tests over the braking process of a newly created solution. The proper value of the braking distance has a significant influence on the value of delay in terms of binding standards. The influence of loading on the effective braking distance and the value of the falling elevator cabin speed are analyzed and the results are presented. The results presented are interesting from lift devices operation and a new model of CHP 2000 progressive gear point of view.

  8. Thermal analysis of both ventilated and full disc brake rotors with frictional heat generation

    Directory of Open Access Journals (Sweden)

    Belhocine A.

    2014-06-01

    Full Text Available In automotive engineering, the safety aspect has been considered as a number one priority in development of a new vehicle. Each single system has been studied and developed in order to meet safety requirements. Instead of having air bags, good suspension systems, good handling and safe cornering, one of the most critical systems in a vehicle is the brake system. The objective of this work is to investigate and analyze 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 discs and to identify the critical temperature of the rotor. The analysis also gives us the heat flux distribution for the two discs.

  9. Study of Dual-redundancy Brushless DC Motor in Electric Aircraft Braking System%飞机刹车用双余度无刷直流电动机的研究

    Institute of Scientific and Technical Information of China (English)

    高金行; 全兴源; 戴志勇; 曹杨

    2012-01-01

    A study of dual redundant brushless DC motor in electric aircraft braking system was given. Based on Ansoft, the motor magnetic circuit was analyzed. The structure parameters were optimized. With the mathematical model of brushless DC motor, the simulation performance was shown. The key technologies of Commutation were analyzed. As shown of experiment, the design is reasonable and correct. Key words; dual redundant brushless DC motor; finite element analysis; performance simulation ; key developing technologies%以全电飞机刹车用双余度无刷直流电动机为研究对象,借助Ansoft软件对电机磁路进行分析计算,优化结构参数,并对其进行性能仿真.重点论述了确保无刷余度电机性能最优的调试关键技术.经过样机性能测试与设计相符,满足使用要求.

  10. Analysis and solution of SS4B braking system high-speeed electric air valve%SS4B型机车制动机高速电空阀故障分析及对策

    Institute of Scientific and Technical Information of China (English)

    张石峰; 刘泉; 万建兵

    2013-01-01

    In this paper ,the principle of SS4B braking system high-speed electric air valve action is introduced ,analysis was carried out to analysis the reason ,running of high-speed locomotive electro-pneumatic valve often appears failure ,it was showed that impu-rities have great influence on high -speed valve failure ,improve air quality ,reduce the presence of impurities ,can effectively reduce the occurrence of high speed valve fault .%  对SS4B型制动机高速电空阀动作的原理做了相关介绍,对在段运行机车高速电空阀经常出现故障的原因进行了分析,研究表明:杂质对高速阀故障的出现有很大的影响,改善空气管路的质量,减少杂质的出现,能有效地减少高速阀故障的发生。

  11. Intelligently Controllable Walker with Magnetorheological Fluid Brake

    Science.gov (United States)

    Kikuchi, Takehito; Tanida, Sosuke; Tanaka, Toshimasa; Kobayashi, Keigo; Mitobe, Kazuhisa

    Caster walkers are supporting frames with casters and wheels. These tools are regularly utilized as life support tools or walking rehabilitation tools in hospitals, nursing homes and individual residences. Users of the walkers can easily move it thanks to its wheels and casters. However falling accidents often happen when it moves without users. The falling accident is very serious problem and one of leading causes of secondary injuries. In the other case, it is hard to move to desired directions if users have imbalance in their motor functions or sensory functions, e.g., hemiplegic patients. To improve safeness and operability of the walkers, we installed compact MR fluid brakes on the wheels and controlled walking speed and direction of the walker. We named this intelligently controllable walker, “i-Walker” and discussed on the control methods and experimental results in this paper. Preliminary trials for direction control of the first-generation of the i-Walker (i-Walker1) are presented. On the basis of the results, we improved the control method and hardware of the i-Walker1, and developed the second-generation (i-Walker2). System description and experimental results of the i-Walker2 are also described. The i-Walker2 has better operability and lower energy consumption than that of the i-Walker1. The line-tracing controller of the i-Walker2 well controls human motions during walking experiments on the target straight line.

  12. A Review of a Study on Disc Brake Noise

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With the development of the automotive industry, disc brake noise has become an issue of growing concern to the automotive industry and customers. In this paper, the types of disc brake noise have been discussed. Ajter that, the theories and models that have been proposed as an explanation of brake squeal are reviewed. On the basis of these theories and models, some example simulations of disc brake squeal which use the Finite Element method and mathematical model have been introduced.

  13. Biweekly Waterfowl Counts from Mathews Brake, Morgan Brake, and Hillside National Wildlife Refuges in 2001 and 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Biweekly Waterfowl Counts from Mathews Brake, Morgan Brake, and Hillside National Wildlife Refuges conducted from October 2001 to February 2002

  14. Hillside, Morgans Brake, and Mathews Brake National Wildlife Refuges Deer Harvest Records are from 2008 and 2014

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These harvest data are from Hillside, Morgans Brake, and Mathews Brake NWRs during the 2008 and 2014 deer seasons. They measure weight, antler size, prevalence of...

  15. Central Mississippi Refuges: Yazoo, Panther Swamp, Hillside, Morgan Brake & Bathews Brake: Annual narrative report: Calendar year 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yazoo, Hillside, Panther Swamp, Morgan Brake, and Mathews Brake NWRs covers refuge activities during 2001. The report begins with a...

  16. 49 CFR 238.315 - Class IA brake test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake test. 238.315 Section 238.315... Requirements for Tier I Passenger Equipment § 238.315 Class IA brake test. (a) Except as provided in paragraph (b) of this section, either a Class I or a Class IA brake test shall be performed: (1) Prior to...

  17. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXVII, I--CATERPILLAR STARTING (PONEY) ENGINE (PART I), II--LEARNING ABOUT BRAKES (PART II).

    Science.gov (United States)

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

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE CONSTRUCTION AND OPERATION OF DIESEL ENGINE STARTING ENGINES AND BRAKE SYSTEMS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) GENERAL DESCRIPTION, (2) OPERATION, (3) COMBUSTION SPACE AND VALVE ARRANGEMENT (STARTING ENGINES), (4) TYPES OF BRAKES, AND (5) DOUBLE…

  18. SPEED ROLLER STAND MEASUREMENT SYSTEM CHECKING TECHNIQUE

    OpenAIRE

    Zybtsev, Y.; I. Marmut

    2011-01-01

    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.

  19. Composite braking control strategy of pure electric bus based on brake driving intention recognition%基于制动驾驶意图辨识的纯电动客车复合制动控制策略

    Institute of Scientific and Technical Information of China (English)

    赵轩; 马建; 汪贵平

    2014-01-01

    To research braking force distribution ratio of composite braking system for pure electric bus,a composite braking control strategy based on brake driving intention recognition was presented.A double-layer brake driving intention recognition model based on hidden Markov theory was set up and identified by using road experiment data.Based on recognized driving intention and vehicle speed,the distribution ratios of braking forces for front and rear wheels, ECE regulation, motor characteristics, slip ratios, battery characteristics, super capacitor characteristics and transmission system characteristics were taken as constraint conditions,the braking force distribution strategy of composite braking system was proposed,and the control strategy of composite braking system was simulated by Simulink software under 9 operating conditions.Simulation result shows that friction braking system and motor regenerative braking system can work coordinately and steadily under various operating conditions when the braking control strategy is applied,and braking energy can be recovered as much as possible under the premise of ensuring braking safety.Energy recovery efficiency is highest under slight brake when vehicle speed was low,and the efficiency can reach to 43 .84%.Energy recovery efficiency is lowest under emergency brake when vehicle speed is high,and the efficiency is only 0. 89%. 2 tabs,21 figs,23 refs.%为了研究纯电动客车复合制动系统制动力分配比例,提出了基于制动驾驶意图辨识的复合制动控制策略。基于隐形马尔科夫理论建立了双层制动驾驶意图辨识模型,运用道路试验数据对模型进行辨识验证。基于辨识出的驾驶意图和车速,以前后轮制动力分配比例、ECE 法规、电机特性、滑移率、蓄电池特性、超级电容特性与传动系统特性为约束条件,制定了复合制动系统制动力分配策略,在9种工况下,应用Simulink对复合制动系统进行建

  20. Analysis of Braking Characteristic for Tire Rotary-drum Machine%轮胎转鼓试验设备制动特性分析

    Institute of Scientific and Technical Information of China (English)

    鲍晓东; 侯勇; 张绍国

    2012-01-01

    制动系统是转鼓试验设备重要的安全部件,通过分析制动系统的材料属性,建立了制动系统的简化模型.对盘式制动器在不同制动压力下的紧急制动过程进行仿真模拟,深入分析了制动系统在不同工作负荷下制动装置摩擦表面的应力、温度场分布情况以及有效的制动时间.对比不同工况下的计算结果,得到了制动盘和刹车片的应力和温度场分布规律,并且分析了制动压力与制动时间之间的关系.结果表明制动压力越大,制动时间越短,但制动系统温升越明显,相关结论为指导设备制动系统参数的合理选定提供了理论依据.%Braking system is an important safety component for the rotating, drum test equipment, through the analysis on the material properties of the braking system, the model of braking system was es-tablishea\\Emergency braking process of the disc brake was simulated under different pressure,and then friction surface stress, temperature field distribution and effective braking time of brake system in different workload stress were further analyzedAccording to the calculation results ,stress and temperature field distribution for braking disc and pad were obtained,and relationship between braking pressure and braking time was analyzed.The results show that as the braking pressure enhanced, the braking time is shorter,however, the temperature rise for braking system is more obvious.Conclusion provides a theoretical basis for brake system rational parameter selection.

  1. Intelligent control for braking-induced longitudinal vibration responses of floating-type railway bridges

    International Nuclear Information System (INIS)

    This paper presents an intelligent control method and its engineering application in the control of braking-induced longitudinal vibration of floating-type railway bridges. Equations of motion for the controlled floating-type railway bridges have been established based on the analysis of the longitudinal vibration responses of floating-type railway bridges to train braking and axle-loads of moving trains. For engineering applications of the developed theory, a full-scale 500 kN smart magnetorheologic (MR) damper has been designed, fabricated and used to carry out experiments on the intelligent control of braking-induced longitudinal vibration. The procedure for using the developed intelligent method in conjunction with the full-scale 500 kN MR dampers has been proposed and used to control the longitudinal vibration responses of the deck of floating-type railway bridges induced by train braking and axle-loads of moving trains. This procedure has been applied to the longitudinal vibration control of the Tian Xingzhou highway and railway cable-stayed bridge over the Yangtze River in China. The simulated results have shown that the intelligent control system using the smart MR dampers can effectively control the longitudinal response of the floating-type railway bridge under excitations of braking and axle-loads of moving trains

  2. Hillside, Morgan Brake, and Mathews Brake National Wildlife Refuges Reforestation Plan for 1992-1996

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan addresses the history of reforestation at Hillside National Wildlife Refuge and its two satellite refuges, Morgan Brake National Wildlife Refuge and...

  3. BRAKING PROCESS OF ENDURO AND HIGHWAY-TOURIST MOTORBIKES

    Directory of Open Access Journals (Sweden)

    Paweł SKRZYPCZYK

    2015-06-01

    Full Text Available In the event of an emergency, head of the motorcycle has a split second to decide what to do defensive maneuver. The most common choice is the braking maneuver. Starting motorcycle braking is associated with the selection of additional brake, which uses a driver. It is here to choose to use the front brake, rear or both simultaneously. The paper presents the study of the effects of such decision on the braking process. Tests were carried out for enduro and highway-tourist motorbikes.

  4. 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.

  5. A High Braking Index for a Pulsar

    CERN Document Server

    Archibald, R F; Ferdman, R D; Kaspi, V M; Guillot, S; Harrison, F A; Keane, E F; Pivovaroff, M J; Stern, D; Tendulkar, S P; Tomsick, J A

    2016-01-01

    We present a phase-coherent timing solution for PSR J1640-4631, a young 206 ms pulsar using X-ray timing observations taken with NuSTAR. Over this timing campaign, we have measured the braking index of PSR J1640-4631 to be n = 3.15+/-0.03. Using a series of simulations, we argue that this unusually high braking index is not due to timing noise, but is intrinsic to the pulsar's spin-down. We cannot, however, rule out contamination due to an unseen glitch recovery, although the recovery timescale would have to be longer than most yet observed. If this braking index is eventually proven to be stable, it demonstrates that pulsar braking indices greater than 3 are allowed in nature, hence other physical mechanisms such as mass or magnetic quadrupoles are important in pulsar spin-down. We also present a 3-sigma upper limit on the pulsed flux at 1.4 GHz of 0.018 mJy.

  6. Asbestos free friction composition for brake linings

    Indian Academy of Sciences (India)

    Arnab Ganguly; Raji George

    2008-02-01

    An asbestos free friction material composite for brake linings is synthesized containing fibrous reinforcing constituents, friction imparting and controlling additives, elastomeric additives, fire retarding components and a thermosetting resin. The composite shows exemplary friction characteristics and has great resistance to wear and shows good temperature stability.

  7. A HIGH BRAKING INDEX FOR A PULSAR

    Energy Technology Data Exchange (ETDEWEB)

    Archibald, R. F.; Ferdman, R. D.; Kaspi, V. M.; Tendulkar, S. P. [Department of Physics and McGill Space Institute, McGill University, 3600 University Street, Montréal, QC H3A 2T8 (Canada); Gotthelf, E. V. [Columbia Astrophysics Laboratory, 550 West 120th Street, New York, NY 10027-6601 (United States); Guillot, S. [Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago (Chile); Harrison, F. A. [Cahill Center for Astrophysics, California Institute of Technology, 1216 East California Boulevard, Pasadena, CA 91125 (United States); Keane, E. F. [SKA Organization, Jodrell Bank Observatory, Cheshire SK11 9DL (United Kingdom); Pivovaroff, M. J. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550-9234 (United States); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Tomsick, J. A. [Space Science Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720-7450 (United States)

    2016-03-01

    We present a phase-coherent timing solution for PSR J1640–4631, a young 206 ms pulsar using X-ray timing observations taken with NuSTAR. Over this timing campaign, we have measured the braking index of PSR J1640–4631 to be n = 3.15 ± 0.03. Using a series of simulations, we argue that this unusually high braking index is not due to timing noise, but is intrinsic to the pulsar's spin-down. We cannot, however, rule out contamination due to an unseen glitch recovery, although the recovery timescale would have to be longer than most yet observed. If this braking index is eventually proven to be stable, it demonstrates that pulsar braking indices greater than three are allowed in nature; hence, other physical mechanisms such as mass or magnetic quadrupoles are important in pulsar spin-down. We also present a 3σ upper limit on the pulsed flux at 1.4 GHz of 0.018 mJy.

  8. Massive star models with magnetic braking

    CERN Document Server

    Meynet, Georges; Maeder, Andre

    2010-01-01

    Magnetic fields at the surface of a few early-type stars have been directly detected. These fields have magnitudes between a few hundred G up to a few kG. In one case, evidence of magnetic braking has been found. We investigate the effects of magnetic braking on the evolution of rotating ($\\upsilon_{\\rm ini}$=200 km s$^{-1}$) 10 M$_\\odot$ stellar models at solar metallicity during the main-sequence (MS) phase. The magnetic braking process is included in our stellar models according to the formalism deduced from 2D MHD simulations of magnetic wind confinement by ud-Doula and co-workers. Various assumptions are made regarding both the magnitude of the magnetic field and of the efficiency of the angular momentum transport mechanisms in the stellar interior. When magnetic braking occurs in models with differential rotation, a strong and rapid mixing is obtained at the surface accompanied by a rapid decrease in the surface velocity. Such a process might account for some MS stars showing strong mixing and low surfa...

  9. Comparative Frictional Analysis of Automobile Drum and Disc Brakes

    Directory of Open Access Journals (Sweden)

    H.P. Khairnar

    2016-03-01

    Full Text Available In the present work, a comparative frictional behaviour of drum brakes and disc brakes in automobiles has been investigated. The influential factors; contact force and friction radius were modeled for the estimation of the friction coefficient for drum as well as disc brakes. The effect of contact force and friction radius is studied with varying conditions of parameters; longitudinal force, caliper force and torque on piston side as well as non-piston side. The numerical results obtained have been compared with the similar obtained from virtual Matlab/Simulink models for drum and disc brakes. The results evidenced that friction radius predominantly affects brake pressure and thus the friction coefficient, also the increase in contact force resulted with decrease in friction coefficient both for drum and disc brakes. Further it has been found that disc brakes exhibit gradual decrease of friction coefficient due to the equitable distribution of braking effort while drum brake presents sudden variations in friction coefficient. It can be revealed that frictional behaviour of disc brake is more consistent than drum brake.

  10. The Effect of Cashew to The Friction Performance Of Automotive Brake Linings

    OpenAIRE

    Timur, Mustafa; Kılıç, Halil; Sugözü, İlker

    2013-01-01

    Brake linings used in automotive disks are usually composed of various components. Expected properties from a brake lining are appropriate standart value of wear resist, friction coefficient and also economical value. Brake lining extremely warms up during braking due to friction. The braking performance of brake lining changes and braking lining is subject to mecanical deformation due to excessive temperature. In recent twenty years in consequence of fast development in automotive technology...

  11. Simulation and analysis of vehicle stability based on ADAMS/CAR differential brake

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the braking safety of automobiles, the author studied the effect of differential brake on the stabilities. To analyze the mechanical characteristics of differential brake, automotive subsystem models were built by applying ADAMS/CAR, and automotive mechanics simulation model was built by setting the main subsystems such as body, engine and brake. The simulation model studied the distribution mode of three kinds of differential brake, and beeline braking stability and turning braking stability wer...

  12. 汽车制动器摩擦试验机测试系统的研究现状及展望%Research Status of Automotive Brake Friction Testing Machine Test System and Its Prospects

    Institute of Scientific and Technical Information of China (English)

    何晨; 梁军战

    2015-01-01

    汽车作为一种现代交通工具,其重要性毋庸置疑。随着汽车保有量的日益增多,汽车的安全问题引起了社会的广泛关注。介绍了汽车制动器摩擦试验机工作原理及特性,对其测试系统各种信号采集方式和数据存储方式的优缺点进行了总结及分析。为了解决目前信号采集误差大、数据不准确和系统稳定性不高等问题,结合汽车制动器摩擦试验机测试系统的研究现状,提出了诸多研究热点,可为汽车制动器摩擦试验机测试系统研究与开发提供参考。%Car is used as a modern transportation means its importance is beyond al doubt. Along with the steep increase of its own ̄ers,the problems of the cars’ s safety atlracts people's extra atlention. This paper not only introduces the working principle and char ̄acteristics of automotive brake friction testing machine ,but also does summarise and analyse the advantages and disadvantages of the signal acquisition method and data storage in the test system. Based on its research status,it puts forward many effective meas ̄ures to solve the problems,such as the wide error limit and low stability. The foundation is laid for its fest.

  13. 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.

  14. Structural optimization of an asymmetric automotive brake disc with cooling channels to avoid squeal

    Science.gov (United States)

    Wagner, Andreas; Spelsberg-Korspeter, Gottfried; Hagedorn, Peter

    2014-03-01

    Brake squeal is still a major issue in the automotive industry due to comfort complaints of passengers and resulting high warranty costs. Many measures to avoid squeal have been discussed in the engineering community reaching from purely passive measures like the increase of damping, e.g. by the application of shims, to the active or semiactive suppression of squeal. While active measures can be effective but are elaborate and therefore more expensive, passive measure are less complex in most cases. This leads to the necessity to develop passive, economic and robust measures to avoid squeal. Asymmetry of the brake rotor has been proposed to achieve this goal and the resulting split of all double eigenfrequencies of the brake rotor has lately been shown to stabilize the system.

  15. Comparison of Regenerative Braking Efficiencies of MY2012 and MY2013 Nissan Leaf

    Directory of Open Access Journals (Sweden)

    Albert Boretti

    2016-07-01

    Full Text Available The use of kinetic energy recovery systems (KERS is the best solution presently available to dramatically improve the energy economy of passenger cars. The paper presents an experimental analysis of the energy flow to and from the battery of a MY 2012 and a MY 2013 Nissan Leaf covering the Urban Dynamometer Driving Schedule (UDDS. The two vehicles differ for the integration of the electric drivetrain component, plus a different use of the electric motor and the regenerative brakes, in addition to a different weight. It is shown that while the efficiency propulsive power to vehicle / power from battery are basically unchanged, at about 87-89 %, the efficiency power to the battery / braking power to vehicle are significantly improved from values of about 70-80 % to values of 72-87 %. The analysis provides a state-of-the-art benchmark of the propulsion and regenerative braking efficiencies of electric vehicles.

  16. Potential wells with a unique brake orbit. Counterexamples to a conjecture by H. Seifert

    CERN Document Server

    Giambo', R; Piccione, P

    2012-01-01

    In this paper we prove the existence of real-analytic natural Hamiltonian systems - i.e. where H(q,p)=T(q,p)+V(q) in the 2N-dimensional real space, where N is any integer greater than 1 - with non critical energy levels E for the potential V such that the sublevel E of V is homeomorphic to the N-dimensional disk, and that only one brake orbit of energy E exists. A famous conjecture formulated by H. Seifert in 1948 claimed the existence of at least N distinct brake orbits for this situation.

  17. Thermomechanical behavior of dry contacts in disc brake rotor with a grey cast iron composition

    Directory of Open Access Journals (Sweden)

    Belhocine Ali

    2013-01-01

    Full Text Available The main purpose of this study is to analysis the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The simulation strategy is based on the calculation code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles. The thermal-structural analysis is then used coupling to determine the deformation established and the Von Mises stresses in the disk, the contact pressure distribution in pads. The results are satisfactory compared to those found in the literature.

  18. Product Quality Improvement Using FMEA for Electric Parking Brake (EPB)

    Science.gov (United States)

    Dumitrescu, C. D.; Gruber, G. C.; Tişcă, I. A.

    2016-08-01

    One of the most frequently used methods to improve product quality is complex FMEA. (Failure Modes and Effects Analyses). In the literature various FMEA is known, depending on the mode and depending on the targets; we mention here some of these names: Failure Modes and Effects Analysis Process, or analysis Failure Mode and Effects Reported (FMECA). Whatever option is supported by the work team, the goal of the method is the same: optimize product design activities in research, design processes, implementation of manufacturing processes, optimization of mining product to beneficiaries. According to a market survey conducted on parts suppliers to vehicle manufacturers FMEA method is used in 75%. One purpose of the application is that after the research and product development is considered resolved, any errors which may be detected; another purpose of applying the method is initiating appropriate measures to avoid mistakes. Achieving these two goals leads to a high level distribution in applying, to avoid errors already in the design phase of the product, thereby avoiding the emergence and development of additional costs in later stages of product manufacturing. During application of FMEA method using standardized forms; with their help will establish the initial assemblies of product structure, in which all components will be viewed without error. The work is an application of the method FMEA quality components to optimize the structure of the electrical parking brake (Electric Parching Brake - E.P.B). This is a component attached to the roller system which ensures automotive replacement of conventional mechanical parking brake while ensuring its comfort, functionality, durability and saves space in the passenger compartment. The paper describes the levels at which they appealed in applying FMEA, working arrangements in the 4 distinct levels of analysis, and how to determine the number of risk (Risk Priority Number); the analysis of risk factors and established

  19. REPORT on the TRUCK BRAKE LINING WORKSHOP and FLEET OPERATORS' SURVEY

    Energy Technology Data Exchange (ETDEWEB)

    Blau, P.J.

    2003-02-03

    The report summarizes what transpired during brake linings-related workshop held at the Fall 2003 meeting of the Technology and Maintenance Council (TMC) in Charlotte, NC. The title of the workshop was ''Developing a Useful Friction Material Rating System''. It was organized by a team consisting of Peter Blau (Oak Ridge National Laboratory), Jim Britell (National Highway Traffic Safety Administration), and Jim Lawrence (Motor and Equipment Manufacturers Association). The workshop was held under the auspices of TMC Task Force S6 (Chassis), chaired by Joseph Stianche (Sanderson Farms, Inc.). Six invited speakers during the morning session provided varied perspectives on testing and rating aftermarket automotive and truck brake linings. They were: James R. Clark, Chief Engineer, Foundation Brakes and Wheel Equipment, Dana Corporation, Spicer Heavy Axle and Brake Division; Charles W. Greening, Jr, President, Greening Test Labs; Tim Duncan, General Manager, Link Testing Services;Dennis J. McNichol, President, Dennis NationaLease; Jim Fajerski, Business Manager, OE Sales and Applications Engineering, Federal Mogul Corporation; and Peter J. Blau, Senior Materials Development Engineer, Oak Ridge National Laboratory. The afternoon break-out sessions addressed nine questions concerning such issues as: ''Should the federal government regulate aftermarket lining quality?''; ''How many operators use RP 628, and if so, what's good or bad about it?''; and ''Would there be any value to you of a vocation-specific rating system?'' The opinions of each discussion group, consisting of 7-9 participants, were reported and consolidated in summary findings on each question. Some questions produced a greater degree of agreement than others. In general, the industry seems eager for more information that would allow those who are responsible for maintaining truck brakes to make better, more informed choices

  20. Simulation and analysis of vehicle stability based on ADAMS/CAR differential brake

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the braking safety of automobiles, the author studied the effect of differential brake on the stabilities. To analyze the mechanical characteristics of differential brake, automotive subsystem models were built by applying ADAMS/CAR, and automotive mechanics simulation model was built by setting the main subsystems such as body, engine and brake. The simulation model studied the distribution mode of three kinds of differential brake, and beeline braking stability and turning braking stability were simulated. It shows that differential brake can amend turning shortage of automobile brake and improve its braking stability, but the effect of automobile mass on its braking stability is great. So the distribution mode of braking force and the effect of mass change should be considered while differential brake is applied.

  1. 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.

  2. 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.

  3. Using ABS Vehicle Braking Performance Analysis%装用ABS车辆的制动性能分析

    Institute of Scientific and Technical Information of China (English)

    王德江

    2012-01-01

    汽车制动系统在汽车的安全方面起着至关重要的作用,ABS在保持汽车制动时的方向稳定性并有限度地缩短制动距离、提高汽车制动安全性方面作用明显,使得全世界对ABS的应用都非常重视。在介绍ABS基本原理的基础上,对车辆制动进行受力分析,通过对有无ABS时的性能进行分析对比,说明有ABS工作时汽车制动力的变化频率大,对工程实践具有指导意义。%The automobile brake system in vehicle safety plays a crucial role in keeping the car,ABS braking directional stability and limit to shorten the braking distance,improve the automobile braking safety aspects of the role,making the whole world for ABS applications are very seriously.On the introduction of ABS on the basis of the basic principle,the vehicle braking force analysis,by contrast with or without ABS performance analysis,illustrates the ABS work of the automobile braking force changes in frequency,the project has guiding significance.

  4. 49 CFR 571.116 - Standard No. 116; Motor vehicle brake fluids.

    Science.gov (United States)

    2010-10-01

    ..., multipurpose passenger vehicles, trucks, buses, trailers, and motorcycles. S4. Definitions. Blister means a..., multipurpose passenger vehicle, truck, bus, trailer, and motorcycle that has a hydraulic brake system shall be... heating mantle designed to fit the flask, or an electric heater with rheostat heat control....

  5. Friction characteristics of a brake friction material under different braking conditions

    International Nuclear Information System (INIS)

    Highlights: • The tribological behavior of the brake material is well depending on interfacial temperature and friction conditions. • The friction performance is influenced by the material heterogeneity and its anisotropy. • The friction performance depended on the nature, morphology and orientation of constituents. - Abstract: As the evaluation of the tribological properties of the brake lining material is important for the braking performance identification, a pad-on-disc friction and wear tests of a commercial brake pad material against cast iron disc were conducted under low, middle and severe conditions. Three experiments via (t1), (t2) and (t3) with different sliding speeds and nominal contact pressure were conducted. Tests were performed with the pad in periodic sliding contact for 30 cycles. The scanning electronic microscopic (SEM) analysis with energy dispersive X-ray (EDX) was used to characterize the rubbed surface. The results showed that during the run-in period, the coefficient of friction increases steadily. For the friction mechanism: (i) at lower conditions, a stable friction film was generated on the surface of the brake pad, providing excellent friction stability with less wear, (ii) at middle conditions, fibers were agglomerated and were not contributed more, and (iii) at higher conditions, contact plates were identified which were accommodated the speed and the load

  6. Wind turbine trailing edge aerodynamic brakes

    Energy Technology Data Exchange (ETDEWEB)

    Migliore, P G [National Renewable Energy Lab., Golden, CO (United States); Miller, L S [Wichita State Univ., KS (United States). Dept. of Aerospace Engineering; Quandt, G A

    1995-04-01

    Five trailing-edge devices were investigated to determine their potential as wind-turbine aerodynamic brakes, and for power modulation and load alleviation. Several promising configurations were identified. A new device, called the spoiler-flap, appears to be the best alternative. It is a simple device that is effective at all angles of attack. It is not structurally intrusive, and it has the potential for small actuating loads. It is shown that simultaneous achievement of a low lift/drag ratio and high drag is the determinant of device effectiveness, and that these attributes must persist up to an angle of attack of 45{degree}. It is also argued that aerodynamic brakes must be designed for a wind speed of at least 45 m/s (100 mph).

  7. Bernoulli effect at free revolving flow braking

    OpenAIRE

    Budarin, V. A.

    2013-01-01

    In this research paper, analytical equations for the calculation of radial flow due to the braking on the flat surface plane of revolving flow were obtained. The calculation method is based on the use of pressure force balance equation, viscid friction and inertia. Three motion equations for incompressible, polytropic and isothermal flow were obtained, the type of a cumulative curve for the incompressible flow has been shown. Possibility of the use of radial flow for the compression of water ...

  8. Elastoplastic finite element analysis for wet multidisc brake during lasting braking

    Directory of Open Access Journals (Sweden)

    Ji Zhanling

    2015-01-01

    Full Text Available Addressed to serious heat degradation problem of the braking continuously performed in the drag brake application for a long time, finite element analysis for bidirectional thermal-structure coupling is adopted to investigate temperature and stress when material properties are temperature-dependent. Based on the constitutive relations of heat transfer and strain-stress, three-dimensional transient finite element equilibrium equations with many kinds of boundary conditions for bidirectional thermal-structure coupling were derived. And it was originally presented that start time, location, severity and evolution laws of plastic deformation were depicted using dimensionless stress distribution contour with the yield limit related to temperature. The change laws of plastic element number and contact area versus braking time were expressed by plasticity ratio and contact ratio curves, respectively. The laws revealed by the numerical calculation results are in accordance with the objective perception and reasoning.

  9. Investigation of the coatings applied onto brake discs on disc-brake pad pair

    Directory of Open Access Journals (Sweden)

    I. Kiliçaslan

    2009-07-01

    Full Text Available While braking, according to the severity of it, thermal, metallurgical, constructive and tribological occurrences emerge on the brake disc-pad interface. In this study, NiCr was sprayed as bonding layer onto the discs, one ofwhich was coated with Al2O3-TiO2 by plasma spray and the other was coated with NiCr-Cr3C2 by High Velocity Oxygen Fuel (HVOF. In addition, the discs were tested with inertia dynamometer according to SAE’s J2522 testing procedure. The measurements showed that although the pads of the coated discs were exposed to higher braking temperatures, friction coefficient of the disc coated with NiCr- Cr3C2 was obtained 6 % higher compared to the original disc.

  10. The Friction of Vehicle Brake Tandem Master Cylinder

    Science.gov (United States)

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

    2006-10-01

    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.

  11. Comparative Frictional Analysis of Automobile Drum and Disc Brakes

    OpenAIRE

    H.P. Khairnar; V.M. Phalle; S. S. Mantha

    2016-01-01

    In the present work, a comparative frictional behaviour of drum brakes and disc brakes in automobiles has been investigated. The influential factors; contact force and friction radius were modeled for the estimation of the friction coefficient for drum as well as disc brakes. The effect of contact force and friction radius is studied with varying conditions of parameters; longitudinal force, caliper force and torque on piston side as well as non-piston side. The numerical results obtained hav...

  12. 盘形制动系统颤振临界速度的计算及分析%Calculation and Analysis of Critical Chattering Velocity in Brake System

    Institute of Scientific and Technical Information of China (English)

    李元元; 丁旺才; 李飞; 张惠

    2011-01-01

    A dynamic model of one-degree-of-freedom disc brake system under dry friction was established,and the mathematical model was constructed based on the theory of differential inclusion, the critical velocity was calculated numerically, and the effects of damping ratio, kinetic frictional coefficient and the difference quantity of maximal static frictional coefficient and kinetic frictional coefficient on critical velocity were discussed separately. Results show that the critical velocity decreases as the damping ratio increases, while increases in pace with the kinetic frictional coefficient, and large difference quantity of maximal static fiictional coefficient and kinetic frictional coefficient will lead large critical velocity when the kinetic frictional coefficient is chosen, when the damping ratio equals to 0. 001 and maximal static frictional coefficient reaches 1.115 times of the kinetic frictional coefficient, the critical velocity becomes invariable and is close to kinetic frictional coefficient.%建立干摩擦的单自由度盘形制动系统动力学模型,基于微分包含理论建立其数学模型,采用数值方法计算系统发生颤振运动的临界速度,并讨论阻尼比、动摩擦因数以及最大静摩擦因数与动摩擦因数之差对临界速度的影响.结果表明:系统发生颤振的临界速度随着阻尼比的增大而减小;随动摩擦因数的增大而增大;在动摩擦因数确定的情况下,随最大静摩擦因数与动摩擦因数之差增大而增大,但最终趋于恒定,在阻尼比ζ=0.001情况下最大静摩擦因数为动摩擦因数1.1 15倍左右时临界速度不再发生变化.

  13. Nonlinear surface models of brake disk dynamics; Nichtlineare Oberflaechenmodelle der Bremsscheibendynamik

    Energy Technology Data Exchange (ETDEWEB)

    Schmalfuss, C.; Wedig, W.; Ams, A. [Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Technische Mechanik

    2000-07-01

    The motor car brake is described as a linear, time-variant model with a single degree of freedom and with nonlinear brake disk surface formulation. Particular regard is given to the changes of direction of the normal and friction forces with variable surfaces. A typical effect is the instability of the brake disk and caliper system which causes critical speed ranges. The authors investigated steady, harmonic and stochastic exchitations resulting from tumbling or surface roughness of the brake disk. The influence of these construction faults is shown up in stability maps. [German] Die KFZ-Bremse wird als lineares, zeitvariantes Modell mit nur einem Freiheitsgrad und nichtlinearer Bremsscheibenoberflaechen-Formulierung betrachtet. Besondere Aufmerksamkeit wird den Richtungsaenderungen der Normal- und Reibungskraefte bei variablen Oberflaechen gewidmet. Ein typischer Effekt ist die Instabilitaet des Systems Bremsscheibe-Bremssattel, welche zu Bereichen kritischer Fahrgeschwindigkeiten fuehrt. Untersucht werden stationaere, harmonische und stochastische Anregungen durch Taumelfehler bzw. Oberflaechenrauhigkeiten der Bremsscheibe. Der Einfluss dieser Bauungenauigkeiten wird in Stabilitaetskarten aufgezeigt. (orig.)

  14. Design and preliminary validation of a tool for the simulation of train braking performance

    Institute of Scientific and Technical Information of China (English)

    Luca Pugi; Monica Malvezzi; Susanna Papini; Gregorio Vettori

    2013-01-01

    Train braking performance is important for the safety and reliability of railway systems. The availability of a tool that allows evaluating such performance on the basis of the main train features can be useful for train system designers to choose proper dimensions for and optimize train’s subsystems. This paper presents a modular tool for the prediction of train braking performance, with a par-ticular attention to the accurate prediction of stopping distances. The tool takes into account different loading and operating conditions, in order to verify the safety require-ments prescribed by European technical specifications for interoperability of high-speed trains and the corresponding EN regulations. The numerical results given by the tool were verified and validated by comparison with experi-mental data, considering as benchmark case an Ansaldo EMU V250 train-a European high-speed train-currently developed for Belgium and Netherlands high-speed lines, on which technical information and experimental data directly recorded during the preliminary tests were avail-able. An accurate identification of the influence of the braking pad friction factor on braking performances allowed obtaining reliable results.

  15. Experimental Study on A New Type of Air-cooled Brake Drum's Braking Performance%自助风冷型制动鼓制动性能试验研究

    Institute of Scientific and Technical Information of China (English)

    赵悟; 杜木伟; 刘晨敏; 沈建军; 于宥源

    2013-01-01

    The structure and cooling mechanisms of a new type of air-cooled brake drum are introduced. Contrast test of temperature rising, brake torque and rotation speed are conducted by the inertia brake tester JF122C between the new type of air-cooled brake drum and the original brake drum. Meanwhile the strength and stiffness of the holes-drilled new type one are analyzed. The result of the contrast test proves that, compared with the original, the average maximum temperature of the new type of air-cooled brake drum is reduced by about 15℃, its average brake torque doesn't change much, and the initial revolving speed and declining trend of every test are alike, the strength and stiffness degrade little, i.e the new type of brake drum greatly improves heat radiating performance of the brake system while maintaining braking safety.%介绍了新型风冷式制动鼓的结构和降温机理.针对新型风冷式制动鼓和原车制动鼓,在JF122C惯性制动试验台上进行了制动鼓温升、制动力矩和转速对比试验,并分析了钻小孔后的新型制动鼓的强度和刚度.试验结果表明,与原车制动鼓相比,新型风冷式制动鼓平均最高温度降低约15℃,平均制动力矩没有明显改变,制动初始转速及下降趋势一致,强度和刚度也未下降.即新型制动豉在保证制动安全性的前提下,较好地改善了制动系统的散热性能.

  16. Petal Brake Hypersonic Entry System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA exploration plans will realize significant performance advantages with aerocapture and aerobraking of large, heavy payloads for Mars, Titan, and the gas...

  17. Squeal and chatter phenomena generated in a mountain bike disc brake

    Science.gov (United States)

    Nakae, Takashi; Ryu, Takahiro; Sueoka, Atsuo; Nakano, Yutaka; Inoue, Takumi

    2011-05-01

    This paper examines squeal and chatter phenomena generated experimentally in mountain bike disc brakes. There are two kinds of frictional self-excited vibrations in the bike disc brakes, called squeal with frequency of 1 kHz and chatter with frequency of 500 Hz. In order to reproduce the squeal and chatter, a bench test apparatus using an actual bike was set up to determine the associated frequency characteristics experimentally. The results show the frequencies to be independent of pad temperature and disc rotating speed. Squeal is shown to be in-plane vibration in the direction of the disc surface which is caused by the frictional characteristics having negative slope with respect to the relative velocity in the vibrating system, which includes brake unit, spokes and hub. Chatter is generated within a limited high temperature region. Again, it is frictional vibration in which the squeal and out-of-plane vibration of the disc due to Coulomb friction combine through the internal resonance relation between in-plane and out-of-plane nonlinear vibration caused by the temperature increase of the disc during braking.

  18. 混合动力履带车辆机电复合制动力分配策略研究%Study on Electric-mechanical Combined Braking Distribution Strategy of Hybrid Electrical Vehicle

    Institute of Scientific and Technical Information of China (English)

    曾庆含; 魏曙光; 魏巍; 马晓军

    2016-01-01

    For the achievement of the braking stability of dual-motor hybrid tracked vehicle with elec-tric-mechanical combined braking system,the braking moment distribution method is proposed based on fuzzy principle. First,the fuzzy controller of braking moment distribution coefficient with accelerate pedal signal and drive velocity as input was designed. And the constraint of electric brake was taken into account for the improvement of matching performance. Then,the electrical drive system,mecha-nical brake system and vehicle dynamical real-time model were set up with the braking process simula-ted in different braking intensities. The simulation results indicate that the combined braking fuzzy con-trol system can recover some braking energy and realize stable braking.%为解决双侧电驱动履带车辆复合制动问题,提出一种机械、电气制动力模糊分配控制策略,通过制定以踏板信号和车辆行驶速度为输入的模糊规则在线实时分配电气、机械制动比例,并考虑电制动实际存在的约束,提高车辆复合制动匹配效果。其次,建立了整车驱动电机系统、机械制动系统以及车辆动力学实时仿真模型,进行了多种制动强度下的驾驶员在环的控制原型仿真试验,仿真结果表明复合制动系统能够在有效回收制动能量的同时,实现平稳制动。

  19. Calculation and Adjustment of Auxiliary Shaft Hoist Braking Torque%副井提升机制动力矩的计算与调整

    Institute of Scientific and Technical Information of China (English)

    丁先亮; 冯庆平; 孙雨生

    2012-01-01

    The main cause of the problem that the deceleration of hoist emergency braking exceeds the standard is the high close brake pressure of brake. Based on the relevant provisions in "Coal Mine Safety Regulation", the paper deduced the inequality to calculate the close brake pressure, so as to calculate the range of identified close brake pressure and debug the brake system. The result can avoid the problem that the deceleration of hoist emergency braking exceeds the standard.%提升机紧急制动减速度超标,主要原因是制动器贴闸压力过高造成的.依据《煤矿安全规程》的相关规定,演绎出计算贴闸压力的不等式,由不等式计算出贴闸压力的取值范围,在取值范围内确定贴闸压力的大小,按确定贴闸压力的大小对制动系统进行调试,其结果就可以避免紧急制动减速度超标的问题.

  20. Quality control of cast brake discs

    Directory of Open Access Journals (Sweden)

    M. Stawarz

    2008-04-01

    Full Text Available The largest industrial application so far have the gray cast irons which are characterized by low tensile and bending strength, while at the same time they have good ultimate comprehensive strength. Additionally, the fatigue strength of gray cast irons is comparatively low and they are only to some extend sensitive for the surface waters effects. Cast iron is the material, which is comparatively easy to be processed, and for this reason – it is not expensive. Brake discs are exploited in particularly hard conditions. They must be resistant both against the thermal fatigue and abrasion wearing (at dry friction as well as against seizing, corrosion and mechanical load [1-3]. The gray cast iron, better than other materials, fulfills all the requirements necessary for making the material for the casts resistant against such tough conditions. This work reflects the researches aiming to define the quality of cast brake discs (ventilated and non-ventilated ones upon a period of their exploitation in real conditions. The following researches were performed: evaluations of the disc surface condition, measurement of disc thickness, examination of run – out flank and metallographic analysis. In order to more detailed recognition of mechanisms and reasons of brake discs wearing in real conditions, one should conduct additional examinations: computer analysis of the microstructure, chemical composition analysis, etc., as well as study of the technology of their production in foundries, where they are manufactured [4]. By obtaining the full set of the mentioned above data one can draw final conclusions and remove causes of possible defects.

  1. THE THEORETICAL MODEL FOR PREDICTING CIRCULATION VELOCITY OF HYDRAULIC BRAKE

    Institute of Scientific and Technical Information of China (English)

    刘英林; 侯春生

    1997-01-01

    By rational hypothesis of fluid flow pattern, applied the law of conservation of energy and integrated the laboratory test results, finished the prediction by the theoretical model of circulation velocity of hydraulic brake which is important parameter. Thus provide the theoritical basis for hydraulic brake of belt conveyor whose research has just been started.

  2. 49 CFR 393.48 - Brakes to be operative.

    Science.gov (United States)

    2010-10-01

    ...) The steering axle of a three-axle dolly which is steered by a co-driver; (5) Loaded house moving... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case...

  3. Design of haptic master featuring small-sized MR brakes

    Science.gov (United States)

    Gang, Han Gyeol; Choi, Seung-Bok; Sohn, Jung Woo

    2016-04-01

    In this work, a new type of haptic master featuring small-sized MR brake is proposed and its performances are evaluated. The proposed haptic master consists of base frame, stick grip and small-sized four MR brakes for 3-DOF rotational motion and 1-DOF gripper motion. To obtain large braking torque under limited small size of MR brake, dual tapered shape inner magnetic core is proposed and its performance is evaluated via both numerical estimation and experimental test. After design and implementation of control algorithm, it has been demonstrated through experiment that the proposed actuator has good performances on tracking control of desired torques. Then, a new haptic master device is designed and constructed by adopting the proposed MR brakes and light weight frame structures. It is verified that the proposed haptic master device is effective for the real application in the field.

  4. A Comparative Study on Automotive Brake Testing Standards

    Science.gov (United States)

    Kumbhar, Bhau Kashinath; Patil, Satyajit Ramchandra; Sawant, Suresh Maruti

    2016-06-01

    Performance testing of automotive brakes involves determination of stopping time, distance and deceleration level. Braking performance of an automobile is required to be ensured for various surfaces like dry, wet, concrete, bitumen etc. as well as for prolonged applications. Various brake testing standards are used worldwide to assure vehicle and pedestrian safety. This article presents methodologies used for automotive service brake testing for two wheelers. The main contribution of this work lies in comparative study of three main brake testing standards; viz. Indian Standards, Federal Motor Vehicle Safety Standards and European Economic Commission Standards. This study shall help the policy makers to choose the best criteria out of these three while formulating newer edition of testing standards.

  5. Design optimization of a magnetorheological brake in powered knee orthosis

    Science.gov (United States)

    Ma, Hao; Liao, Wei-Hsin

    2015-04-01

    Magneto-rheological (MR) fluids have been utilized in devices like orthoses and prostheses to generate controllable braking torque. In this paper, a flat shape rotary MR brake is designed for powered knee orthosis to provide adjustable resistance. Multiple disk structure with interior inner coil is adopted in the MR brake configuration. In order to increase the maximal magnetic flux, a novel internal structure design with smooth transition surface is proposed. Based on this design, a parameterized model of the MR brake is built for geometrical optimization. Multiple factors are considered in the optimization objective: braking torque, weight, and, particularly, average power consumption. The optimization is then performed with Finite Element Analysis (FEA), and the optimal design is obtained among the Pareto-optimal set considering the trade-offs in design objectives.

  6. Development of Asbestos - Free Brake Pad Using Bagasse

    Directory of Open Access Journals (Sweden)

    V. S. Aigbodion

    2010-03-01

    Full Text Available Development of asbestos-free brake pad using bagasse was investigated with a view to replace the use of asbestos whose dust is carcinogenic. The bagasse were sieve into sieve grades of 100, 150, 250, 350 and 710µm. the sieve bagasse was used in production of brake pad in ratio of 70%bagasse-30%resin using compression moulding. The properties examined are microstructure analysis, hardness, compressive strength, density, flame resistance, water and oil absorption. The microstructure reveals uniform distribution of resin in the bagasse. The results obtained showed that the finer the sieve size the better the properties. The results obtained in this work were compared with that of commercial brake pad (asbestos based and optimum formulation laboratory brake pad Palm Kernel Shell based (PKS, the results are in close agreement. Hence bagasse can be used in production of asbestos-free brake pad.

  7. SEE SAW BASED REGENERATIVE POWER SYSTEM

    OpenAIRE

    Tribhuwan Singh; Shahzad Ali

    2016-01-01

    Research related to electrical vehicles is gaining importance due to the energy crisis. 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 utilizes a seesaw system to capture energy whereas the conventional systems regenerate to the batteries. The user ha...

  8. SEE SAW CREATED RECREATING POWER SYSTEM

    OpenAIRE

    Sameer Singh*, Saha Ali

    2016-01-01

    Research related to electrical vehicles is gaining importance due to the energy crisis. 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 utilizes a seesaw system to capture energy whereas the conventional systems regenerate to the batteries. The user ha...

  9. STATISTIC, PROBABILISTIC, CORRELATION AND SPECTRAL ANALYSES OF REGENERATIVE BRAKING CURRENT OF DC ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    A. V. Nikitenko

    2014-04-01

    Full Text Available Purpose. Defining and analysis of the probabilistic and spectral characteristics of random current in regenerative braking mode of DC electric rolling stock are observed in this paper. Methodology. The elements and methods of the probability theory (particularly the theory of stationary and non-stationary processes and methods of the sampling theory are used for processing of the regenerated current data arrays by PC. Findings. The regenerated current records are obtained from the locomotives and trains in Ukraine railways and trams in Poland. It was established that the current has uninterrupted and the jumping variations in time (especially in trams. For the random current in the regenerative braking mode the functions of mathematical expectation, dispersion and standard deviation are calculated. Histograms, probabilistic characteristics and correlation functions are calculated and plotted down for this current too. It was established that the current of the regenerative braking mode can be considered like the stationary and non-ergodic process. The spectral analysis of these records and “tail part” of the correlation function found weak periodical (or low-frequency components which are known like an interharmonic. Originality. Firstly, the theory of non-stationary random processes was adapted for the analysis of the recuperated current which has uninterrupted and the jumping variations in time. Secondly, the presence of interharmonics in the stochastic process of regenerated current was defined for the first time. And finally, the patterns of temporal changes of the correlation current function are defined too. This allows to reasonably apply the correlation functions method in the identification of the electric traction system devices. Practical value. The results of probabilistic and statistic analysis of the recuperated current allow to estimate the quality of recovered energy and energy quality indices of electric rolling stock in the

  10. Radial brake assembly for a control rod drive

    International Nuclear Information System (INIS)

    This patent describes a brake assembly for a control rod drive for selectively preventing travel of a control rod in a nuclear reactor vessel. It comprises a shaft having a longitudinal centerline axis; means for selectively rotating the shaft in a first direction and in a second direction, opposite to the first direction; a stationary housing having a central aperture receiving the shaft; a frame fixedly joined to the housing and having a guide hole; a rotor disc fixedly connected to the shaft for rotation therewith and having at least one rotor tooth extending radially outwardly from a perimeter thereof, the rotor tooth having a locking surface and an inclined surface extending therefrom in a circumferential direction; a brake member disposed adjacent to the rotor disc perimeter and including a base, at least one braking tooth having a locking surface extending therefrom in a circumferential direction, and a plunger extending radially outwardly from the base and slidably joined to the frame through the guide hole; the rotor tooth and the braking tooth being complementary to each other; and means for selectively positioning the brake member in a deployed position abutting the rotor disc perimeter for allowing the braking tooth locking surface to contact the rotor tooth locking surface for preventing rotation of the shaft in the first direction, and in a retracted position spaced radially away from the rotor disc for allowing the rotor disc and the shaft to rotate without restraint from the brake member, the positioning means including a tubular solenoid fixedly joined to the frame and having a central bore disposed around the brake member plunger and effective for sliding the brake member plunger relative to the frame for positioning the brake member in the deployed and retracted positions

  11. Non-linear 2-DOF model and centre manifold theory to study limit cycle oscillations caused by drum-brake judder

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ming-gang; HUANG Qi-bai; WANG Yong; XU Zhi-sheng

    2007-01-01

    This paper presents the research on the laws of systematic-parameter dependent variation in the vibration amplitude of drum-brake limit cycle oscillations (LCO). We established a two-degree non-linear dynamic model to describe the low-frequency vibration of the drum brake, applied the centre manifold theory to simplify the system, and obtained the LCO amplitude by calculating the normal form of the simplified system at the Hopf bifurcation point. It is indicated that when the friction coefficient is smaller than the friction coefficient at the bifurcation point, the amplitude decreases; whereas with a friction coefficient larger than the friction coefficient of bifurcation point, LCO occurs. The results suggest that it is applicable to suppress the LCO amplitude by changing systematic parameters, and thus improve the safety and ride comfort when applying brake. These findings can be applied to guiding the design of drum brakes.

  12. 动车组电空制动协调控制优化研究%Research on Optimization of Electro-pneumatic Braking Cooperative Control for EMU

    Institute of Scientific and Technical Information of China (English)

    朱琴跃; 包世炯; 谭喜堂; 王东响

    2013-01-01

    分析现有动车组电空制动控制系统中的制动力分配策略,针对动车与拖车电空制动力施加不均的问题,提出一种电空制动协调控制优化策略。采用动车电制动优先的控制原则,并根据载重反比分配拖车与动车所需施加的空气制动力。以 CRH2型动车组中一动一拖为基本单元,利用Matlab/Simulink软件对列车在不同制动工况进行仿真,结果表明,基于载重反比分配制动力的电空制动协调优化控制策略可有效提高列车制动效率,减小动车与拖车的车轮踏面磨损。%On analysis of the braking force distribution strategy in existing Electric Multiple Unit(EMU) electro-pneumatic braking control system, an optimization strategy of electro-pneumatic braking cooperative control is proposed, which aims at solving the imbalance problem of the motor car and trailer car’s electro-pneumatic braking. It uses electro-pneumatic braking priority control principle in EMU, and distributes air braking force of motor car and trailer car in inverse ratio on the basic of load. By modeling the EMU electro-pneumatic cooperative braking control and braking force distribution optimized algorithm while taking one motor car and one trailer car in CRH2 EMU as the basic unit, the Matlab/Simulink software is used to simulate different braking condition. The results indicate that the electro-pneumatic cooperative braking control optimization strategy which based on the load inverse-proportion for braking force distribution has the significant effect on improving brake efficiency, reducing wheel tread wear of the motor car and the trailer car.

  13. 49 CFR 236.554 - Rate of pressure reduction; equalizing reservoir or brake pipe.

    Science.gov (United States)

    2010-10-01

    ... or brake pipe. 236.554 Section 236.554 Transportation Other Regulations Relating to Transportation...; Locomotives § 236.554 Rate of pressure reduction; equalizing reservoir or brake pipe. The equalizing-reservoir pressure or brake-pipe pressure reduction during an automatic brake application shall be at a rate not...

  14. Optimal design of a disc-type MR brake for middle-sized motorcycle

    Science.gov (United States)

    Nguyen, Quoc-Hung; Jeon, Juncheol; Choi, Seung-Bok

    2011-03-01

    This research work focuses on optimal design of a disc-type magneto-rheological (MR) brake that can replace a conventional hydraulic brake (CHB) of middle-sized motorcycles. Firstly, a MR brake configuration is proposed considering the available space and the simplicity to replace a CHB by the proposed MR brake. An optimal design of the proposed MR brake is then performed considering the required braking torque, operating temperature, mass and size of the brake. In order to perform the optimization of the brake, the braking torque of the brake is analyzed based on Herschel-Bulkley rheological model of MR fluid. The constrain on operating temperature of the MR brake is determined by considering the steady temperature of the brake when the motorcycle is cruising and the temperature increase during a braking process. An optimization procedure based on finite element analysis integrated with an optimization tool is employed to obtain optimal geometric dimensions of the MR brake. Optimal solution of the MR brake is then presented and simulated performance of the optimized brake is shown with remarkable discussions.

  15. 泵控电液混合驱动系统在板料折弯机上的应用研发%The application and exploration of pump-control electro-hydraulic driving system in press brake for sheet metal

    Institute of Scientific and Technical Information of China (English)

    李振光; 汪立新; 温峰虎; 雷斌华; 茅问宇

    2013-01-01

    The electric and hydraulic principles of the pump-control electro-hydraulic driving system have been introduced in the text, as well as the advantages of pump-control press brake comparing with the conventional one. It is pointed out that the application of pump-control electro-hydraulic driving system is more widely, which has a broad marketing prospect.%介绍了泵控电液混合驱动系统的电气原理、液压原理,以及与传统折弯机相比泵控折弯机的诸多优点,指出泵控电液混合驱动系统的应用将越来越广泛,具有广阔的市场前景.

  16. THEORETICAL AND EXPERIMENTAL ANALYSIS OF LOADING IMPACT FROM THE PROGRESSIVE GEAR ON THE LIFT BRAKING DISTANCE WITH THE USE OF THE FREE FALL METHOD

    Directory of Open Access Journals (Sweden)

    Paweł Lonkwic

    2016-06-01

    Full Text Available The gear which is the central safety element of the friction drive lift during braking is exposed to overloading connected with changeable weight which loads the lift braking system. In the article the results of numerical analysis for braking process of CHP 2000 type progressive gear distinguished by an innovative design have been presented. The numerical analysis was conducted with the use of a simulation of the gear roller displacement depending on changeable loading with the support of Abaqus/CAE software. Displacement of the gear roller from the neutral position in which the gear starts loosing energy of speeding up weight to zero was simulated. The results obtained from computer simulations were verified on the basis of a physical experiment at the bench station created to verify braking parameters of the gears with the use of free fall method.

  17. Regenerative braking control strategy in mild hybrid electric vehicles equipped with automatic manual transmission

    Institute of Scientific and Technical Information of China (English)

    QIN Datong; YE Ming; LIU Zhenjun

    2007-01-01

    The actual regenerative braking force of an integrated starter/generator (ISG),which is varied with desired braking deceleration and vehicle speed,is calculated based on an analysis of the required deceleration,maximum braking force of ISG,engine braking force and state of charge (SOC) of battery.Braking force distribution strategies are presented according to the actual regenerative braking force of ISG.To recover the vehicle's kinetic energy maximally,braking shift rules for a mild hybrid electric vehicle (HEV) equipped with automatic manual transmission (AMT) are brought forward and effects of transmission ratios are considered.A test-bed is built up and regenerative braking tests are carried out.The results show that power recovered by the braking shift rules is more than that recovered by the normal braking control rules.

  18. A modified approach to transient stability enhancement with fast valving and braking resistor applications

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Ramnarayan [Indian Institute of Technology, Roorkee, Uttaranchal (India). Department of Electrical Engineering; Bhatti, T.S.; Kothari, D.P. [Indian Institute of Technology, Delhi, New Delhi (India). Centre for Energy Studies

    2006-12-15

    Fast valving and braking resistor are two important members of the family of the discrete supplementary controllers (DISCOS). Both of these are very effective and economic means of transient stability enhancement under extreme contingencies. Being stationed at the similar end of a power system the two schemes carry a very good potential of an effective coordination. Such a coordinated control is helpful not only in obtaining an improved gain in stability, but also in overcoming the limitations and avoiding excessive duty on the part of an individual controller. In this work, a detailed study has been carried out to evaluate the scope and limitations of fast valving and dynamic braking resistor controls in enhancing the transient stability of power systems. Improvements have been suggested over the conventional schemes of control so as to improve their adaptability under different conditions of fault and loading or with different types of generating units. (author)

  19. 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.

  20. C/C composite brake disk nondestructive evaluation by IR thermography

    Science.gov (United States)

    Chu, Tsuchin P.; Poudel, Anish; Filip, Peter

    2012-06-01

    This paper discusses the non-destructive evaluation of thick Carbon/Carbon (C/C) composite aircraft brake disks by using transient infrared thermography (IRT) approach. Thermal diffusivity measurement technique was applied to identify the subsurface anomalies in thick C/C brake disks. In addition, finite element analysis (FEA) modeling tool was used to determine the transient thermal response of the C/C disks that were subjected to flash heating. For this, series of finite element models were built and thermal responses with various thermal diffusivities subjected to different heating conditions were investigated. Experiments were conducted to verify the models by using custom built in-house IRT system and commercial turnkey system. The analysis and experimental results showed good correlation between thermal diffusivity value and anomalies within the disk. It was demonstrated that the step-heating transient thermal approach could be effectively applied to obtain the whole field thermal diffusivity value of C/C composites.

  1. Residual stresses in a cast iron automotive brake disc rotor

    Energy Technology Data Exchange (ETDEWEB)

    Ripley, Maurice I. [Australian Nuclear Scinece and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)]. E-mail: m.ripley@ansto.gov.au; Kirstein, Oliver [Australian Nuclear Scinece and Technology Organisation, PMB 1, Menai, NSW 2234 (Australia)

    2006-11-15

    Runout, and consequent juddering and pulsation through the brake pedal, is a multi-million dollar per year warranty problem for car manufacturers. There is some suspicion that the runout can be caused by relaxation of residual casting stresses when the disc is overheated during severe-braking episodes. We report here neutron-diffraction measurements of the levels and distribution of residual strains in a used cast iron brake disc rotor. The difficulties of measuring stresses in grey cast iron are outlined and three-dimensional residual-strain distributions are presented and their possible effects discussed.

  2. Retardation-controlled safety brake at the test site

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, A.; Schroeder, R.; Sondermann, W.

    1989-02-01

    A double-drum winding installation is thought to require a retardation-controlled safety brake. The investigations needed for the design acceptance of such a braking installation have so far only been possible on an actual winding installation. This has not ruled out that the commissioning procedure of the whole installation could be delayed or endangered. The use of a simulator developed by the WBK Rope Testing Station, which replicates the behaviour of braked masses in the winding installation, made it possible for the first time to transfer a major part of the necessary investigations to the test site.

  3. New Phase-coherent Measurements of Pulsar Braking Indices

    CERN Document Server

    Livingstone, M A; Gavriil, F P; Manchester, R N; Gotthelf, E V; Kuiper, L; Livingstone, Margaret A.; Kaspi, Victoria M.; Gavriil, Fotis P.; Manchester, Richard N.; Kuiper, Lucien

    2007-01-01

    Pulsar braking indices offer insight into the physics that underlies pulsar spin-down. Only five braking indices have been measured via phase-coherent timing; all measured values are less than 3, the value expected from magnetic dipole radiation. Here we present new measurements for three of the five pulsar braking indices, obtained with phase-coherent timing for PSRs J1846-0258 (n=2.65+/-0.01), B1509-58 (n=2.839+/-0.001) and B0540-69 (n=2.140+/-0.009). We discuss the implications of these results and possible physical explanations for them.

  4. MODIFICATION OF FLAKE REINFORCED FRICTION BRAKE COMPOSITE MATERIAL

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to the recent development trend and need of the friction brake material, the flake reinforced friction brake material has been made out by adjusting the recipe and techniques. The two-dimensional flake vermiculite is selected as the reinforced stuffing of the material; the modified resin is used as the basal bed of the material. The tests manifest that the properties of mechanics are high, the friction coefficients are suitable and stable,and especially in high temperatures the wear is low. It is an excellent friction brake material.

  5. Residual stresses in a cast iron automotive brake disc rotor

    International Nuclear Information System (INIS)

    Runout, and consequent juddering and pulsation through the brake pedal, is a multi-million dollar per year warranty problem for car manufacturers. There is some suspicion that the runout can be caused by relaxation of residual casting stresses when the disc is overheated during severe-braking episodes. We report here neutron-diffraction measurements of the levels and distribution of residual strains in a used cast iron brake disc rotor. The difficulties of measuring stresses in grey cast iron are outlined and three-dimensional residual-strain distributions are presented and their possible effects discussed

  6. CARS WEAVE IN THE BRAKING POSITION OF A HUMP

    Directory of Open Access Journals (Sweden)

    D. O. Serheiev

    2009-09-01

    Full Text Available The work contains a theoretical study of freight car vibrations while a group of the freight cars are under braking by retarder. The purpose is to discover possible causes of derailment. The corresponding analytical description is presented. The solution of the differential equations for the groups of carriages confirms an assumption, according to which a contact between the carriage wheel of and the rail can be lost due to the oscillations induced by braking. The results allow to present recommendation for choosing the safe regime of braking in order to avoid the derailment.

  7. Gravitational waves from pulsars with measured braking index

    CERN Document Server

    de Araujo, Jose C N; Costa, Cesar A

    2016-01-01

    We study the putative emission of gravitational waves (GWs) in particular for pulsars with measured braking index. We show that the appropriate combination of both GW emission and magnetic dipole brakes can naturally explain the measured braking index, when the surface magnetic field and the angle between the magnetic dipole and rotation axes are time dependent. Then we discuss the detectability of these very pulsars by aLIGO and the Einstein Telescope. We call attention to the realistic possibility that aLIGO can detect the GWs generated by at least some of these pulsars, such as Vela, for example.

  8. 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.

  9. A Pulsar Eases Off the Brakes

    Science.gov (United States)

    Kohler, Susanna

    2015-10-01

    In 2006, pulsar PSR 18460258 unexpectedly launched into a series of energetic X-ray outbursts. Now a study has determined that this event may have permanently changed the behavior of this pulsar, raising questions about our understanding of how pulsars evolve.Between CategoriesA pulsar a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation can be powered by one of three mechanisms:Rotation-powered pulsars transform rotational energy into radiation, gradually slowing down in a predictable way.Accretion-powered pulsars convert the gravitational energy of accreting matter into radiation.Magnetars are powered by the decay of their extremely strong magnetic fields.Astronomical classification often results in one pesky object that doesnt follow the rules. In this case, that object is PSR 18460258, a young pulsar categorized as rotation-powered. But in 2006, PSR 18460258 suddenly emitted a series of short, hard X-ray bursts and underwent a flux increase behavior that is usually only exhibited by magnetars. After this outburst, it returned to normal, rotation-powered-pulsar behavior.Since the discovery of this event, scientists have been attempting to learn more about this strange pulsar that seems to straddle the line between rotation-powered pulsars and magnetars.Unprecedented DropOne way to examine whats going on with PSR 18460258 is to evaluate whats known as its braking index, a measure of how quickly the pulsars rotation slows down. For a rotation-powered pulsar, the braking index should be roughly constant. The pulsar then slows down according to a fixed power law, where the slower it rotates, the slower it slows down.In a recent study, Robert Archibald (McGill University) and collaborators report on 7 years worth of timing observations of PSR 18460258 after its odd magnetar-like outburst. They then compare these observations to 6.5 years of data from before the outburst. The team finds that the braking index for this bizarre

  10. Comparisonal Analysis of Manuevering and Braking

    Directory of Open Access Journals (Sweden)

    Artūras Žukas

    2011-04-01

    Full Text Available This article covers the possibility of avoiding a traffic accident considering a car driver who is fallen in a dangerous situation. In such a case, the driver can choose one of the following ways: hard braking or one of the types of maneuvering, including turning off, turning with straightening or changing a line regarding road surface type (dry asphalt, wet asphalt or snowy asphalt. The article also proposes formulas for calculating road distance the car travels till dead stop. Moreover, the tables display theoretical values taking into account various car speeds and road surfaces. The pictures help with determining the most suitable type of action in light of road and weather conditions as well as car speed. The pictures clearly show the dependence of road length on movement speed. At the end of the article, conclusions are proposed.Article in Lithuanian

  11. Determination Of Correlation Between Road Pavement Skid Resistance And Braking Deceleration

    OpenAIRE

    KOKOT, D; Rijavec, R.; Ambroz, M.

    2012-01-01

    There are many situations when road pavement surface skid resistance drops to unacceptable levels. Skid resistance is an essential pavement property for road safety, but drivers are not able to assess its degree by visual means, although in the end they must be able to stop their vehicles safely within the stopping sight distance. In our research normalized braking deceleration was related to SCRIMTEX SFC values and analyzed for different driving conditions (wet/dry), vehicle systems, skid re...

  12. Investigation of the relationship between damping and mode-coupling patterns in case of brake squeal

    OpenAIRE

    Fritz, Guillaume; Sinou, Jean-Jacques; Duffal, Jean-Marc; Jezequel, Louis

    2007-01-01

    International audience Brake squeal is a friction induced instability phenomenon that has to be addressed during the development process. The mechanism is considered a mode coupling phenomenon also referred to as coalescence. The system eigenvalues have been computed using a technique based on the finite element method. The coalescence patterns were then determined in relation to the friction coefficient. The effects of damping on the coalescence patterns have been investigated. If the two...

  13. Flatness-based model inverse for feed-forward braking control

    Science.gov (United States)

    de Vries, Edwin; Fehn, Achim; Rixen, Daniel

    2010-12-01

    For modern cars an increasing number of driver assistance systems have been developed. Some of these systems interfere/assist with the braking of a car. Here, a brake actuation algorithm for each individual wheel that can respond to both driver inputs and artificial vehicle deceleration set points is developed. The algorithm consists of a feed-forward control that ensures, within the modelled system plant, the optimal behaviour of the vehicle. For the quarter-car model with LuGre-tyre behavioural model, an inverse model can be derived using v x as the 'flat output', that is, the input for the inverse model. A number of time derivatives of the flat output are required to calculate the model input, brake torque. Polynomial trajectory planning provides the needed time derivatives of the deceleration request. The transition time of the planning can be adjusted to meet actuator constraints. It is shown that the output of the trajectory planning would ripple and introduce a time delay when a gradual continuous increase of deceleration is requested by the driver. Derivative filters are then considered: the Bessel filter provides the best symmetry in its step response. A filter of same order and with negative real-poles is also used, exhibiting no overshoot nor ringing. For these reasons, the 'real-poles' filter would be preferred over the Bessel filter. The half-car model can be used to predict the change in normal load on the front and rear axle due to the pitching of the vehicle. The anticipated dynamic variation of the wheel load can be included in the inverse model, even though it is based on a quarter-car. Brake force distribution proportional to normal load is established. It provides more natural and simpler equations than a fixed force ratio strategy.

  14. Fishery Management Plan for Morgan Brake National Wildlife Refuge - 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This management plan was prepared by the U. S. Fish and Wildlife Service for Morgan Brake National Wildlife Refuge. Data was provided by the Refuge and Area Office...

  15. Handy Brake National Wildlife Refuge Habitat Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Handy Brake National Wildlife Refuge Habitat Management Plan provides a long-term vision and specific guidance on managing habitats for the resources of concern...

  16. Deployable Engine Air-Brake for Drag Management Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA Engineering, Inc, proposes an SBIR program to demonstrate an innovative engine air-brake (EAB) technology that uses a deployable swirl vane mechanism to switch...

  17. Deployable Engine Air-Brake for Drag Management Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA Engineering, Inc., (ATA) proposes a Phase II SBIR program to demonstrate an innovative engine air-brake (EAB) technology that uses a deployable swirl vane...

  18. Fishery Management Plan for Mathews Brake National Wildlife Refuge - 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This management plan was prepared by the U.S. Fish and Wildlife Service for Mathew's Brake National Wildlife Refuge. Data was provided by the refuge and area office...

  19. Fishing Plan for Mathews Brake National Wildlife Refuge - 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal calls for the opening of Mathews Brake NWR to sport fishing. General regulations pertaining to licenses, creel limits, and methods of taking fish will...

  20. Crayfish survey at Morgan Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Crayfish sampling on Morgan Brake NWR for vernal crawfish and other species was done for 3 days at five sites. Data are present on species of crawfish and...

  1. 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.

  2. Nonlinear time series analysis of vibration data from a friction brake: SSA, PCA, and MFDFA

    International Nuclear Information System (INIS)

    We use the methodology of singular spectrum analysis (SSA), principal component analysis (PCA), and multi-fractal detrended fluctuation analysis (MFDFA), for investigating characteristics of vibration time series data from a friction brake. SSA and PCA are used to study the long time-scale characteristics of the time series. MFDFA is applied for investigating all time scales up to the smallest recorded one. It turns out that the majority of the long time-scale dynamics, that is presumably dominated by the structural dynamics of the brake system, is dominated by very few active dimensions only and can well be understood in terms of low dimensional chaotic attractors. The multi-fractal analysis shows that the fast dynamical processes originating in the friction interface are in turn truly multi-scale in nature

  3. The Calculation and Verification of the High Speed Train Braking Curve%高速列车制动曲线的计算与验证

    Institute of Scientific and Technical Information of China (English)

    张友兵; 张波

    2012-01-01

    分析了列车运行过程中的受力情况,给出了制动过程中减速度的计算方法,并采用正向、反向两种迭代方式计算列车制动曲线,两种方式计算出的制动曲线一致,证明了计算制动曲线的方法是正确的.在反向迭代计算制动曲线时,缩小距离步长,可以提高制动曲线的精确度,选择合适的距离步长,不但能保证精确度,而且可以满足时效性.通过仿真得出,在平直道上,CRH2型高速列车在初始速度为300km/h时,紧急制动距离为2 780m,最大常用制动距离为4 628m,符合国家规定.分析了制动过程中列车减速度与速度的关系.最后,分析了制动初始速度与制动距离的关系,发现制动初始速度越大,制动距离越长,且制动距离非线性增大.%In CTCS-3 train control system, the on-board equipment uses the target distance and continuous speed control mode to control the train. In order to ensure the train safety, the on-board equipment must calculate the braking curve based on the movement authority and adjust the train speed in real time. In this paper, the forces which are applied to the train are analyzed, and the calculation method of deceleration when the train is braking is given. The train braking curves are calculated by using forward and reverse iterative methods. The methods of calculating the train braking curve are proved to be correct. In the process of reversely and iteratively calculating the braking curve,narrowing the distance step can improve the accuracy of the braking curve,selecting the appropriate distance length not only can ensure the accuracy of the braking curve but also can meet the timeliness of calculating the braking curve, and The simulation result proves that the emergency braking distance of CRH2 high-speed trains is 2 780 m,the max normal braking distance is 4 628 m if the initial speed of the train is 300 km/h and the train is running on the flat and straight line. These results comply with the

  4. OPTIMAL EMERGENCY VEHICLE BRAKING CONTROL BASED ON DYNAMIC FRICTION MODEL

    Directory of Open Access Journals (Sweden)

    L. Olmos

    2005-04-01

    Full Text Available A dynamic friction model for the tire-road interface is used in an optimal control scheme for emergency braking ofvehicles. The controller sets a target relative velocity curve that the vehicle must track in order to achieve braking inminimum time. It is shown that this curve corresponds to the solution of a minimum time optimal control problem.The final goal of the control is to improve the safety levels in highway transportation.

  5. AASPT Carbon/Carbon Aircraft Brake Disk Granted MPA

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Xi'an Chaoma Technology Co. Ltd. was issued Parts Manufacturer Approval (PMA) for Carbon/Carbon aircraft brake disk for Airbus 320 series by Civil Aviation Administration of China (CAAC). The company is held by Academy of Aerospace Solid Propulsion Technology (AASPT), a subsidiary of China Aerospace Science and Technology Corporation (CASC). It is the first approval given to a Chinese company to design and produce brakes for main civilian aircraft.

  6. OPTIMAL EMERGENCY VEHICLE BRAKING CONTROL BASED ON DYNAMIC FRICTION MODEL

    OpenAIRE

    Olmos, L.; L. Álvarez-Icaza

    2005-01-01

    A dynamic friction model for the tire-road interface is used in an optimal control scheme for emergency braking of vehicles. The controller sets a target relative velocity curve that the vehicle must track in order to achieve braking in minimum time. It is shown that this curve corresponds to the solution of a minimum time optimal control problem. The final goal of the control is to improve the safety levels in highway transportation.

  7. Model problem about evaluation of the temperature field in the uniformly rotating wheel at interaction with the disk brake

    OpenAIRE

    Anatolii I. Zadorozhnyi; Igor V. Kolesnikov

    2011-01-01

    In the article the axially symmetric mixed problem of heat conduction for a system «a wheel-disk brake» is considered. The solution is obtained by Fox method of average and method of joining of the solutions on a demarcation line between the boundary conditions.

  8. Model problem about evaluation of the temperature field in the uniformly rotating wheel at interaction with the disk brake

    Directory of Open Access Journals (Sweden)

    Anatolii I. Zadorozhnyi

    2011-05-01

    Full Text Available In the article the axially symmetric mixed problem of heat conduction for a system «a wheel-disk brake» is considered. The solution is obtained by Fox method of average and method of joining of the solutions on a demarcation line between the boundary conditions.

  9. Development of automobile brake lining using pulverized cow hooves

    Directory of Open Access Journals (Sweden)

    Katsina C. BALA

    2016-06-01

    Full Text Available Asbestos has been used for so long as automobile brake lining material because of its good physical and chemical properties. However, due to the health hazard associated with its handling, it has lost favour and several alternative materials are being increasingly used. Asbestos-free brake lining was developed in this work using pulverized cow hooves along with epoxy resin, barium sulphate, graphite and aluminium oxide. This was with a view to exploiting the characteristics of cow hooves, which are largely discarded as waste materials to replace asbestos which has been found to be carcinogenic. Samples of brake linings were produced using compressive moulding in which the physical and mechanical properties of the samples were studied. The results obtained showed that proper bonding was achieved as the percentage by weight of epoxy resin increased and percentage by weight of pulverized cow hooves decreased. The hardness, compressive strength, coefficient of friction, water and oil absorption, relative density and wear rate of the brake linings were determined and compared with existing brake lining properties. The result indicates that pulverized cow hooves can be used as brake lining material for automobiles.

  10. Wear Modalities and Mechanisms of the Mining Non-asbestos Composite Brake Material

    Science.gov (United States)

    Bao, Jiusheng; Yin, Yan; Zhu, Zhencai; Tong, Minming; Lu, Yuhao; Peng, Yuxing

    2013-08-01

    The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures.

  11. Turbine turbobrake systems

    Science.gov (United States)

    Goodisman, Michael I.

    Short duration rotating turbine facilities are a recent development in the field of turbine research. Turbine braking devices can be used to maintain the turbine at the desired test speed, resulting in a longer usable test time. The Isentropic Light Piston Cascade at the Defence Research Agency in Pyestock will perform heat transfer and aerodynamic tests on the first stage of a Rolls-Royce turbine (MT1) linked to a new type of brake, the 'axial turbo brake'. The axial turbo brake is driven by the turbine's exhaust gas and is isolated from the turbine by a choked throat. The turbo brake's power absorption must be controlled to match the power developed by the turbine stage for a constant speed run. Both the turbo brake blade shape and novel power control system were developed from tests on a 0.17 scale test rig. The turbo brake's braking is controlled through by-pass of flow over the blade tips and partial blockage of the turbo brake's exit annulus. Also described is the mechanical design, development and manufacture of the full size turbo brake, turbine disc and turbine blades, which have been successfully spun tested to their overspeed condition. Finally, a theory for self-pumping turbo brakes is developed. These devices would have additional applications because they do not require a supply of high pressure gas to drive them.

  12. Electrophysiology-based detection of emergency braking intention in real-world driving

    Science.gov (United States)

    Haufe, Stefan; Kim, Jeong-Woo; Kim, Il-Hwa; Sonnleitner, Andreas; Schrauf, Michael; Curio, Gabriel; Blankertz, Benjamin

    2014-10-01

    Objective. The fact that all human action is preceded by brain processes partially observable through neuroimaging devices such as electroencephalography (EEG) is currently being explored in a number of applications. A recent study by Haufe et al (2011 J. Neural Eng. 8 056001) demonstrates the possibility of performing fast detection of forced emergency brakings during driving based on EEG and electromyography, and discusses the use of such neurotechnology for braking assistance systems. Since the study was conducted in a driving simulator, its significance regarding real-world applicability needs to be assessed. Approach. Here, we replicate that experimental paradigm in a real car on a non-public test track. Main results. Our results resemble those of the simulator study, both qualitatively (in terms of the neurophysiological phenomena observed and utilized) and quantitatively (in terms of the predictive improvement achievable using electrophysiology in addition to behavioral measures). Moreover, our findings are robust with respect to a temporary secondary auditory task mimicking verbal input from a fellow passenger. Significance. Our study serves as a real-world verification of the feasibility of electrophysiology-based detection of emergency braking intention as proposed in Haufe et al (2011 J. Neural Eng. 8 056001).

  13. A statistical approach to estimate the LYAPUNOV spectrum in disc brake squeal

    Science.gov (United States)

    Oberst, S.; Lai, J. C. S.

    2015-01-01

    The estimation of squeal propensity of a brake system from the prediction of unstable vibration modes using the linear complex eigenvalue analysis (CEA) in the frequency domain has its fair share of successes and failures. While the CEA is almost standard practice for the automotive industry, time domain methods and the estimation of LYAPUNOV spectra have not received much attention in brake squeal analyses. One reason is the challenge in estimating the true LYAPUNOV exponents and their discrimination against spurious ones in experimental data. A novel method based on the application of the ECKMANN-RUELLE matrices is proposed here to estimate LYAPUNOV exponents by using noise in a statistical procedure. It is validated with respect to parameter variations and dimension estimates. By counting the number of non-overlapping confidence intervals for LYAPUNOV exponent distributions obtained by moving a window of increasing size over bootstrapped same-length estimates of an observation function, a dispersion measure's width is calculated and fed into a BAYESIAN beta-binomial model. Results obtained using this method for benchmark models of white and pink noise as well as the classical HENON map indicate that true LYAPUNOV exponents can be isolated from spurious ones with high confidence. The method is then applied to accelerometer and microphone data obtained from brake squeal tests. Estimated LYAPUNOV exponents indicate that the pad's out-of-plane vibration behaves quasi-periodically on the brink to chaos while the microphone's squeal signal remains periodic.

  14. Electro-mechanical Braking Method in Hybrid Electric Vehicles Based on Feedback Control Theory

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; YU Jun-quan; LIU Zheng-yu; CHANG Cheng

    2014-01-01

    In this paper, the hybrid electric vehicle braking process is researched, by using variables consists of HEV speed, motor speed, and state of charge established, functions of mechanical braking force, regenerative braking force and efficiency of energy recovery are constructed, and the control goal is to maximization the energy recovery efficiency. Under the feedback control strategy, with the constrain condition of braking strength and braking stability, combining experiments in ADVISOR, in different experiments of different working conditions, we can see that in UDDS Cycle, the regenerative braking efficiency is the best. What’s more, compared with strategies in ADVISOR, strategy proposed in this paper is obviously better.

  15. Effect of Friction Model and Tire Maneuvering on Tire-Pavement Contact Stress

    Directory of Open Access Journals (Sweden)

    Haichao Zhou

    2015-01-01

    Full Text Available This paper aims to simulate the effects of different friction models on tire braking. A truck radial tire (295/80R22.5 was modeled and the model was validated with tire deflection. An exponential decay friction model that considers the effect of sliding velocity on friction coefficients was adopted for analyzing braking performance. The result shows that the exponential decay friction model used for evaluating braking ability meets design requirements of antilock braking system (ABS. The tire-pavement contact stress characteristics at various driving conditions (static, free rolling, braking, camber, and cornering were analyzed. It is found that the change of driving conditions has direct influence on tire-pavement contact stress distribution. The results provide the guidance for tire braking performance evaluation.

  16. Influence of Brake Characteristics on Longitudinal Impulse of Train%制动特性对列车纵向冲动的影响

    Institute of Scientific and Technical Information of China (English)

    魏伟; 武星宇

    2012-01-01

    针对大秦线重载列车实际运用中出现的纵向冲动过大的问题,使用基于气体流动理论的空气制动特性仿真和基于刚体动力学的列车纵向动力学联合仿真方法,研究制动波传播的均匀性、制动波速、制动缸升压特性等制动系统特性对纵向冲动的影响.结果表明在制动波速不变条件下,制动波匀速传播与非匀速传播时列车纵向冲动水平基本一致;制动波速对列车车钩力影响显著,波速越高,车钩力越小;在列车制动能力不变的条件下,随着列车首尾车制动缸压强曲线开口度的收敛,纵向冲动明显降低,最大车钩力发生位置向列车后部移动.%Referring to excessive longitudinal impulse of Da-Qin heavy haul trains in practice, co-simulation of air braking characteristics based on gas flow theory and train longitudinal dynamics based on rigid body kinetics are used to study the effects of braking system characteristics (uniformity of brake propagation, brake propagation speed and pressure increasing speed of brake cylinder, etc. )on longitudinal impulse. The results show that under the conditions of same brake propagation speed, train longitudinal impulse of uniform and non-uniform brake propagation are basically consistent, and brake propagation speed affects coupler force significantly. The faster the brake speed is, the smaller the coupler force is. Under the conditions of same stopping distance with the convergence of front and rear vehicle's brake cylinder pressure curves, longitudinal impulse is reduced significantly, and the locations of maximum coupler force are moved towards the rear of train.

  17. The braking force in walking: age-related differences and improvement in older adults with exergame training.

    Science.gov (United States)

    Maillot, Pauline; Perrot, Alexandra; Hartley, Alan; Do, Manh-Cuong

    2014-10-01

    The purposes of this present research were, in the first study, to determine whether age impacts a measure of postural control (the braking force in walking) and, in a second study, to determine whether exergame training in physically-simulated sport activity would show transfer, increasing the braking force in walking and also improving balance assessed by clinical measures, functional fitness, and health-related quality of life in older adults. For the second study, the authors developed an active video game training program (using the Wii system) with a pretest-training-posttest design comparing an experimental group (24 1-hr sessions of training) with a control group. Participants completed a battery comprising balance (braking force in short and normal step conditions), functional fitness (Senior Fitness Test), and health-related quality of life (SF-36). Results show that 12 weeks of video game-based exercise program training improved the braking force in the normal step condition, along with the functional fitness of lower limb strength, cardiovascular endurance, and motor agility, as measured by the Senior Fitness Test. Only the global mental dimension of the SF-36 was sensitive to exergame practice. Exergames appear to be an effective way to train postural control in older adults. Because of the multimodal nature of the activity, exergames provide an effective tool for remediation of age-related problems. PMID:24231655

  18. Prosthetic leg powered by MR brake and SMA wires

    Science.gov (United States)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  19. Hall drift and the braking indices of young pulsars

    CERN Document Server

    Gourgouliatos, K N

    2014-01-01

    Braking index measurements of young radio pulsars are all smaller than the value expected for spin down by magnetic dipole braking. We investigate magnetic field evolution in the neutron star crust due to Hall drift as an explanation for observed braking indices. Using numerical simulations and a semi-analytic model, we show that a $\\approx 10^{14}\\ {\\rm G}$ quadrupolar toroidal field in the neutron star crust at birth leads to growth of the dipole moment at a rate large enough to agree with measured braking indices. A key factor is the density at which the crust yields to magnetic stresses that build up during the evolution, which sets a characteristic minimum Hall timescale. The observed braking indices of pulsars with inferred dipole fields of $\\lesssim 10^{13}\\ {\\rm G}$ can be explained in this picture, although with a significant octupole component needed in some cases. For the stronger field pulsars, those with $B_d\\gtrsim 10^{13}\\ {\\rm G}$, we find that the magnetic stresses in the crust exceed the max...

  20. Unusual Braking Indices in Young X-ray Pulsars

    Science.gov (United States)

    Frederic Archibald, Robert; Kaspi, Victoria M.; Beardmore, Andrew P.; Gehrels, Neil; Kennea, Jamie; Gotthelf, Eric V.; Ferdman, Robert; Guillot, Sebastien; Harrison, Fiona; Keane, Evan; Pivovaroff, Michael; Stern, Daniel; Tendulkar, Shriharsh P.; Tomsick, John

    2016-04-01

    Pulsars spin down over time. By measuring braking indices of pulsars, effectively the change in the spin-down rate over time, we can probe the underlying driving engine of the spin-down. For a magnetic dipole in a vacuum, n is predicted to be 3. To date, all measured braking indices are less than 3, which can be explained, e.g. by particle winds, changes in the magnetic field. In all models of braking indices, n should be nearly constant on year time-scales. Here, I will discuss two recent observation results that challenge this model, interestingly both coming from young X-ray pulsars with no detected radio emission. The first, a long-lived decrease in the braking index of PSR J1846-0258 following a burst of magnetar-like activity, and secondly, the first stationary braking index greater than three. Understanding neutron-star spin evolution is key to constraining these objects' long-term energy output and has relevance to topics ranging from pulsar wind nebulae and supernova remnants to core-collapse supernova rates, physics, and expected outcomes.

  1. Adaptation of hybrid five-phase ABS algorithms for experimental validation

    OpenAIRE

    Gerard, Mathieu; Pasillas-Lépine, William; De Vries, Edwin; Verhaegen, Michel

    2010-01-01

    The Anti-lock Braking System (ABS) is the most important active safety system for passenger cars, but unfortunately the literature is not really precise about its description, stability and performance. This research improves a five-phase hybrid algorithm based on wheel deceleration and validate it on a tyre-in-the-loop laboratory facility. Five relevant effects are modelled so that the simulation matches the reality. Two methods to deal with the time delays are proposed. It can be verified t...

  2. 电动汽车

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Analysis of performance results from Future Truck 2001;Analytical Calculation of Air-Gap Magnetic Field Distribution and Instantaneous Characteristics of Brushless DC Motors;Application of Fuzzy Control Algorithms for Electric Vehicle Antilock Braking/Traction Control Systems;Application Studies of Electric Double Layer Capacitor System for Fuel Cell Vehicle;Arbin High Power Electric Vehicle Battery Testing System (EVTS) “Advanced Technology Reaching Deep Into the Future”……

  3. TIre/road friction estimation

    OpenAIRE

    DELANNE, Y; VANDANJON, PO

    2006-01-01

    In board tire/road friction estimation is of current interest in two different framework : - optimization of driver assistance systems efficiency : antilock braking system, electronic stability program, adaptive cruise control, lane departure control, advanced automatic driving, etc., - driver instantaneous warning about the available friction and limits for his possible driving actions. This subject has been the objective of many research programs throughout the world. Four main methods have...

  4. Freshwater Fish Survey of Mathews Brake Water Body - 1980 and 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A Freshwater Fish Survey of Mathews Brake water body including land not within Mathews Brake NWR. Methods included Electroshocker, creel census, and seine.

  5. Constraining t-T conditions during palaeoseismic events - constraining the viscous brake phenomena in nature.

    Science.gov (United States)

    Dobson, Katherine J.; Kirkpatrick, James D.; Mark, Darren F.; Stuart, Finlay M.

    2010-05-01

    Melt generated by frictional heating during an earthquake is generally assumed to act as a lubricant, and decrease the frictional resistance to sliding. However, recent experimental [1] and theoretical [2] studies indicate that this might not always be the case. When the earthquake starts, melts form in isolated small patches along the fault, and only later coalesce into more extensive sheets. While the pockets of melt are isolated they have a high resistance to viscous shear and increase the overall strength of the fault: an effect known as the ‘viscous brake'. The experimental and theoretical data suggest that the melt pockets can actually stop an earthquake. The crucial parameter that controls if the viscous brake can operate is the normal stress working on the system, which is a function of the mass (i.e. the thickness) of rock above the rupture. It is impossible to directly observe or sample the earthquake source in active faults, and natural examples of the viscous brake have yet to be identified. We present a novel study that uses a combination of low temperature thermochronometry techniques to investigate the viscous brake in nature, by taking advantage of exhumed faults that preserve a record of ancient earthquakes; i.e pseudotachylytes. Pseudotachylytes are chilled frictional melts and are the only accepted indicator of ancient seismicity along faults. Pseudotachylytes found in the central part of the Sierra Nevada mountain range, California, are thin (indicate that the pseudotachylytes formed at temperatures of time-temperature cooling path of the host rock to be determined and the geothermal gradient to be assessed, which in turn allows us calculate the depth at which rupture occurred. We use these results to test the hypothesis that the Sierra Nevada pseudotachylyte acted as a viscous brake. This will ultimately improve understanding of earthquake ruptures by identifying an intrinsic control on the magnitude of earthquakes. References 1. Di Toro et

  6. Investigation of Friction Behaviors of Brake Shoe Materials using Metallic Filler

    OpenAIRE

    E. Surojo; Jamasri; V. Malau; M.N. Ilman

    2015-01-01

    Some vehicles use brake shoe made from semi-metallic materials. Semi-metallic brake shoes are made from a combination of metallic and non-metallic materials. Metallic particles are added in the formulation of brake shoe material to improve composites characteristics. In this paper, friction behaviors of brake shoe material using metallic filler were investigated. Machining chips of cast iron and copper wire of electric motor used were incorporated in composite as metallic fillers with amount ...

  7. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Science.gov (United States)

    2010-10-01

    ... steering axle of a truck, truck-tractor or bus shall not be less than 4.8 mm (3/16 inch) at the shoe center....6 mm (1/16 inch) or less for hydraulic disc, drum and electric brakes. (2) Non-steering axle brakes... for drum brakes); or less than 3.2 mm (1/8 inch) for disc brakes. Hydraulic or electric...

  8. What can the braking indices tell us about pulsars' nature?

    CERN Document Server

    Yue, Y L; Zhu, W W

    2006-01-01

    As a result of observational difficulties, braking indices of only six rotation-powered pulsars are obtained with certainty, all of which are remarkably smaller than the value ($n=3$) expected for pure magnetodipole radiation model. This is still a real fundamental question not being well answered after nearly forty years of the discovery of pulsar. The main problem is that we are shamefully not sure about the dominant mechanisms that result in pulsars' spin-down. Based on the previous works, the braking index is re-examined, with a conclusion of suggesting a constant gap potential drop for pulsars with magnetospheric activities. New constrains on model parameters from observed braking indices are presented.

  9. Braking the Gas in the beta Pictoris Disk

    CERN Document Server

    Fern'andez, R; Wu, Y; Brandeker, Alexis; Fern\\'andez, Rodrigo

    2006-01-01

    (Abridged) The main sequence star beta Pictoris hosts the best studied circumstellar disk to date. Nonetheless, a long-standing puzzle has been around since the detection of metallic gas in the disk: radiation pressure from the star should blow the gas away, yet the observed motion is consistent with Keplerian rotation. In this work we search for braking mechanisms that can resolve this discrepancy. We find that all species affected by radiation force are heavily ionized and dynamically coupled into a single fluid by Coulomb collisions, reducing the radiation force on species feeling the strongest acceleration. For a gas of solar composition, the resulting total radiation force still exceeds gravity, while a gas of enhanced carbon abundance could be self-braking. We also explore two other braking agents: collisions with dust grains and neutral gas. Grains surrounding beta Pic are photoelectrically charged to a positive electrostatic potential. If a significant fraction of the grains are carbonaceous (10% in t...

  10. Dynamics Models of Interacting Torques of Hydrodynamic Retarder Braking Process

    Directory of Open Access Journals (Sweden)

    Wenhao Shen

    2013-01-01

    Full Text Available Hydrodynamic retarder is a kind of assist braking device, which can transfer the vehicle kinetic energy into the heat energy of working medium. There are complicated three-dimensional viscous incompressible turbulent flows in hydrodynamic retarder, so that it is difficult to represent the parameters changing phenomenon and investigate the interactional law. In order to develop a kind of reliable theoretical model for internal flow field, in this study, the dynamics models of interacting torques between impellers and working fluid were constructed based on braking energy transfer principle by using Euler theory to describe the flow state in view of time scale. The model can truly represent the dynamic braking process.

  11. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  12. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    Science.gov (United States)

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-01-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in…

  13. Investigation of Product Performance of Al-Metal Matrix Composites Brake Disc using Finite Element Analysis

    Science.gov (United States)

    Fatchurrohman, N.; Marini, C. D.; Suraya, S.; Iqbal, AKM Asif

    2016-02-01

    The increasing demand of fuel efficiency and light weight components in automobile sectors have led to the development of advanced material parts with improved performance. A specific class of MMCs which has gained a lot of attention due to its potential is aluminium metal matrix composites (Al-MMCs). Product performance investigation of Al- MMCs is presented in this article, where an Al-MMCs brake disc is analyzed using finite element analysis. The objective is to identify the potentiality of replacing the conventional iron brake disc with Al-MMCs brake disc. The simulation results suggested that the MMCs brake disc provided better thermal and mechanical performance as compared to the conventional cast iron brake disc. Although, the Al-MMCs brake disc dissipated higher maximum temperature compared to cast iron brake disc's maximum temperature. The Al-MMCs brake disc showed a well distributed temperature than the cast iron brake disc. The high temperature developed at the ring of the disc and heat was dissipated in circumferential direction. Moreover, better thermal dissipation and conduction at brake disc rotor surface played a major influence on the stress. As a comparison, the maximum stress and strain of Al-MMCs brake disc was lower than that induced on the cast iron brake disc.

  14. 基于CBTC的车载ATP安全制动曲线计算模型研究%Computational Model of Safe Braking Curve of Onboard ATP Based on CBTC

    Institute of Scientific and Technical Information of China (English)

    林颖; 王长林

    2011-01-01

    车载ATP系统是保证列车运行安全的系统,其中的关键技术之一是安全制动曲线计算模型.根据IEEE 1474.1TM标准的规定[1],车载ATP安全制动曲线由GEBR制动曲线和ATP紧急制动触发曲线组成.GEBR制动曲线是根据GEBR计算得出的,而ATP紧急制动触发曲线则是根据GEBR制动曲线计算出来的.针对该问题,本文分析了各种影响列车制动距离的因素和GEBR制动曲线与ATP紧急制动触发曲线的关系,建立了CBTC率载ATP安全制动曲线的计算模测.仿真证明,本文提出的计算模型满足IEEE 1474.1TM基于CBTC的车载ATP安全制动模型的要求.%The onboard ATP system is the system which protects train running safety. One of its key technologies is the computational model of the safe braking curve. According to IEEE 1474.1?, the on-board ATP safe braking curve is made up of the GEBR braking curve and the ATP emergency brake triggering curve. The GEBR braking curve is calculated by GEBR and the ATP emergency brake triggering curve is calculated by the GEBR braking curve. This paper analyzes various factors influencing the train braking distance and the relationship between the GEBR braking curve and the ATP emergency brake triggering curve, and establishes the computational model of safe braking curve of onboard ATP based on CBTC . Simulation proves that the model of this paper satisfies the IEEE 1474.1? Requirements for the safe braking model of onboard ATP based on CBTC.

  15. Dynamic interaction of brakes, tyres and road surface; Dynamische Interaktion Bremse - Reifen - Strasse

    Energy Technology Data Exchange (ETDEWEB)

    Huinink, H.; Schroeder, C.

    1999-12-01

    Rubber friction of rough surfaces is characterised by the molecular physics of the highly dynamic interaction between a polymer network and the road on nano- micrao- and macroscale length. The problems of power transmission of ALS-controlled tyres at quasi-stationary conditions (interaction tyres/braking system) are described by the grip/slip characteristics defined for the area of tyre contact, which in terms forms the basis for the interaction between material and road surface (according to Persson 1997) under the respective technical conditions of the vehicle. ALS-braking with time-dependent brake torque is a technically highly dynamic system state within the interaction of material, tyres, vehicle and road surface. New systems based on sensors such as the side-torsion-sensor made by Continental AG improve safety, comfort and economy by combining this feature with a vehicle management system which uses tyre forces and -deformation as input parameters. [Deutsch] Die Gummireibung auf rauhen Oberflaechen ist durch eine molekulare Physik der hochdynamischen Interaktion Polymernetzwerk / Fahrbahn auf nano-, mikro- und makroskaligen Laengen gekennzeichnet. Die Problematik der Kraftuebertragung bei ABS-geregelten Reifen unter quasistationaeren Bedingungen (Interaktion Reifen - Bremssystem) wird durch die in der Bodenaufstandsflaeche ortsaufgeloesten Kraftschluss - Schlupf - Kennlinien erfasst, deren Basis die Interaktion Material / Fahrbahn nach Persson (1997) unter den gegebenen technischen Bedingungen am Fahrzeug darstellt. Der ABS-Bremsvorgang bei zeitabhaengigem Bremsmoment ist ein technisch hochdynamischer Systemzustand im Wechselspiel Material - Reifen - Fahrzeug-Fahrbahn. Auf der Sensorik basierende dynamische Systemerweiterungen, wie z.B. durch den Seitenwand-Torsions-Sensor der Continental AG, verbessern Fahrsicherheit, Komfort und Wirtschaftlichkeit durch die Kombination mit einem Fahrzeugmanagementsystem, das die Reifenkraefte und -verformungen als

  16. 一种汽车盘式电磁制动器的研制%Research and manufacture of electromagnetic brake disc on automobile

    Institute of Scientific and Technical Information of China (English)

    龙云梅; 林秋逢; 曾竞; 何荣欣; 彭马保; 曾文高; 陈伟涛

    2013-01-01

    为解决目前汽车液压制动系统存在结构复杂、质量大、能源消耗大等问题,将电磁制动技术应用到汽车制动系统中.开展了盘式电磁制动器增力机构建模和应力仿真分析,建立了制动踏板行程与电流大小以及制动力之间的对应关系,提出了以电磁铁作为动力源,通过增力机构把电磁力放大到预期制动力推动摩擦片工作而实现汽车制动的方法;在理论分析和试验的基础上对电磁力控制、汽车防抱死性能、制动热稳定性等多方面进行了评价;对实体模型的制动稳定性、电磁力随衔铁与铁芯之间距离的变化关系、电磁线圈通电电流与踏板行程之间的变化关系等进行了试验.试验结果表明:电磁铁力达到780 N,制动系统反应时间为0.019 6 s,均符合汽车制动要求;电磁制动系统相比液压制动系统具有反应迅速、结构简单以及更易于集成化和远程控制等特点.%In order to solve the problem of the hydraulic brake system of automobile for its complicate structure, heavy weight and great drain on the resources, the electromagnetic brake technology was applied to the automobiles. After the analysis of disc electromagnetic brake reinforcement structure modeling and stress simulation, the corresponding relationship between the brake pedal travel, current size and braking force was established. A method was presented that taking electromagnetic as the power source and through the reinforcement structure enlarge the electromagnetic force to the expected brake force and drive the friction brake to make the car brake become true. Based on theoretically calculation and experiment, the control of electromagnetic force, ABS performance and the thermal stability of the brake were evaluated. On the solid model, the stability of electromagnetic brake, the varing of the electromagnetic force between the distance of gag bit and iron core, the varing between the current of the

  17. Simulation on Series Electro-hydraulic Combined Braking for 4WD Hybrid Electric Car%四驱混合动力轿车串联式电液复合制动仿真

    Institute of Scientific and Technical Information of China (English)

    赵治国; 彭玉钢

    2012-01-01

    针对自主开发的四轮驱动混合动力轿车,设计了串联式制动能量回收系统。基于制动安全性和最大化回收制动能量的原则,提出了ABS液压制动与再生制动协调控制的电液复合制动控制策略。该策略先根据驾驶员的操作实时计算制动强度和总需求制动力矩,然后依据制动强度大小对总需求制动力矩进行分配,并且实时检测车轮滑移率以判断是否切换到ABS独立工作模式。并在Simulink软件平台上建立了样车动力传动、制动系统及控制策略模型,分别在轻度、中度和紧急制动三种制动工况下仿真了串联式制动能量回收系统的性能。仿真结果表明:所提出的电液复合制动控制策略能有效地提高制动能量的回收效率,且在紧急制动时能保证车辆的制动稳定性能。%A new type of series regenerative braking system was designed for 4WD-hybrid electric car.Based on a principle of braking safety and maximize energy recovery,a electro-hydraulic combined braking control strategy for the sake of coordinately controlled between regenerative braking and ABS hydraulic braking was proposed.This strategy firstly calculated the braking strength and the braking torque required on the basis of driver's operation,then according to braking strength,the braking torque required was distributed,besides judging when would the operating mode switch to ABS mode by real-time detection of slip ratio.Simulation model including powertrain,braking system and control strategy was modeled on Matlab/Simulink,the performance of Series Regenerative Braking system was respectively verified in the condition of slight braking,moderate braking and emergency braking.The simulation results show that the proposed strategy obviously improves the braking energy recovery efficiency,meanwhile making sure that the car has a good braking performance in an emergency braking condition.

  18. Real-Time Estimation of the Distribution of Brake Response Times for an Individual Driver Using Vehicular Ad Hoc Network

    OpenAIRE

    Rakhshan, Ali; Ray, Evan; Pishro-Nik, Hossein

    2014-01-01

    Adapting the functioning of the collision warning systems to the specific drivers' characteristics is of great benefit to drivers. For example, by customizing collision warning algorithms we can minimize false alarms, thereby reducing injuries and deaths in highway traffic accidents. In order to take the behaviors of individual drivers into account, the system needs to have a Real-Time estimation of the distribution of brake response times for an individual driver. In this paper, we propose a...

  19. HXD2B机车Eurotrol制动机控制分析%Analysis of Eurotrol Braking Machine Control of HXD2B Locomotives

    Institute of Scientific and Technical Information of China (English)

    王颖平; 张向

    2013-01-01

    Introduce the braking control system priciple, braking control unit BCU and pre-control RE pressure control working principle of HXD2B electric locomotive. It focuses on analysing and studying the design plan and control principle of pre-braking, common braking, cou⁃ple-broken protection, operation monitoring, alleviating, holding pressure, overcharging, elimination, neutral and emergency braking, etc.%  介绍HXD2B电力机车制动控制系统原理、制动控制单元BCU和预控RE压力控制工作原理。重点分析和研究了一次缓解模式下,初制动、常用制动、断钩保护、运行监控、缓解、保压、过充及消除、中立、紧急制动等功能的设计方案和控制原理。

  20. A new hybrid spring brake orthosis for controlling hip and knee flexion in the swing phase.

    Science.gov (United States)

    Gharooni, S; Heller, B; Tokhi, M O

    2001-03-01

    In this study it is proposed that active contraction of muscles might be artificially replaced by a spring brake orthosis (SBO) to provide near-natural knee and hip swing phase trajectories for gait in spinal cord injured subjects. The SBO is a new gait restoration system in which stored spring elastic energy and potential energy of limb segments are utilized to aid gait. It is also shown that hip flexion can be produced without the need for withdrawal reflex, hip flexor stimulus or any mechanical actuator at the hip. A hip flexion angle of 21 degrees was achieved by a nonimpaired subject wearing a prototype orthosis.

  1. Computational thermo-fluid analysis of a disk brake

    Science.gov (United States)

    Takizawa, Kenji; Tezduyar, Tayfun E.; Kuraishi, Takashi; Tabata, Shinichiro; Takagi, Hirokazu

    2016-06-01

    We present computational thermo-fluid analysis of a disk brake, including thermo-fluid analysis of the flow around the brake and heat conduction analysis of the disk. The computational challenges include proper representation of the small-scale thermo-fluid behavior, high-resolution representation of the thermo-fluid boundary layers near the spinning solid surfaces, and bringing the heat transfer coefficient (HTC) calculated in the thermo-fluid analysis of the flow to the heat conduction analysis of the spinning disk. The disk brake model used in the analysis closely represents the actual configuration, and this adds to the computational challenges. The components of the method we have developed for computational analysis of the class of problems with these types of challenges include the Space-Time Variational Multiscale method for coupled incompressible flow and thermal transport, ST Slip Interface method for high-resolution representation of the thermo-fluid boundary layers near spinning solid surfaces, and a set of projection methods for different parts of the disk to bring the HTC calculated in the thermo-fluid analysis. With the HTC coming from the thermo-fluid analysis of the flow around the brake, we do the heat conduction analysis of the disk, from the start of the breaking until the disk spinning stops, demonstrating how the method developed works in computational analysis of this complex and challenging problem.

  2. Oxygen-Diffused Titanium as a Candidate Brake Rotor Material

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

    2009-01-01

    Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

  3. Can dark matter explain the braking index of neutron stars?

    DEFF Research Database (Denmark)

    Kouvaris, C.; Perez-Garcia, M. A.

    2014-01-01

    We explore a new mechanism of slowing down the rotation of neutron stars via accretion of millicharged dark matter. We find that this mechanism yields pulsar braking indices that can be substantially smaller than the standard n similar to 3 of the magnetic dipole radiation model for millicharged...... dark matter particles that are not excluded by existing experimental constraints thus accommodating existing observations....

  4. 49 CFR 571.106 - Standard No. 106; Brake hoses.

    Science.gov (United States)

    2010-10-01

    ... Vehicle Safety Standards § 571.106 Standard No. 106; Brake hoses. S1. Scope. This standard specifies... end fittings. S2. Purpose. The purpose of this standard is to reduce deaths and injuries occurring as.... S3. Application. This standard applies to passenger cars, multipurpose passenger vehicles,...

  5. Chinese Enterprises Slams the Brakes on Acquisition of Overseas Mines

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>On June 25,China Mining Association revealed that,as of the middle of June,Chinese enterprises slammed the brakes on acquisition of overseas mines.There are only 53 overseas mine acquisition cases so far this year,

  6. Braking index of isolated pulsars: open questions and ways forward

    CERN Document Server

    Hamil, Oliver

    2015-01-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities $\\Omega$, and their time derivatives which show unambiguously that the pulsars are slowing down. Although the exact mechanism of the spin-down is a question of debate, the commonly accepted view is that it arises either through emission of magnetic dipole radiation (MDR) from a rotating magnetized body, through emission of a relativistic particle wind, or via higher order magnetic multipole or gravitational quadrupole radiation. The calculated energy loss by a rotating pulsar is model dependent and leads to the power law $\\dot{\\Omega}$ = -K $\\Omega^{\\rm n}$ where $n$ is called the braking index. The theoretical value for braking index is $n = 1, 3, 5$ for wind, MDR, quadrupole radiation respectively. The accepted view is that pulsar braking is strongly dominated by MDR. Highly precise observations of isolated pulsars yield braking index values in the range $1 < n < 2.8$ which are consistently less than the value pred...

  7. Can Dark Matter explain the Braking Index of Neutron Stars?

    CERN Document Server

    Kouvaris, Chris

    2014-01-01

    We explore a new mechanism of slowing down the rotation of neutron stars via accretion of millicharged dark matter. We find that this mechanism yields pulsar braking indices that can be substantially smaller than the standard $n\\sim 3$ of the magnetic dipole radiation model for millicharged dark matter particles that are not excluded by existing experimental constraints thus accommodating existing observations.

  8. Coaxial magnetic brakes using single-domain YBCO

    Energy Technology Data Exchange (ETDEWEB)

    Putman, P.T. [Texas Center for Superconductivity and Department of Mechanical Engineering, University of Houston, Houston, TX 77204 (United States)], E-mail: pputman@uh.edu; Salama, K. [Texas Center for Superconductivity and Department of Mechanical Engineering, University of Houston, Houston, TX 77204 (United States)

    2008-06-15

    In coaxial magnetic brakes, the changing field produced by movement of a solenoidal magnet induces a current in the wall of a conductive tube. The interaction of the field and current leads to a repulsive force that slows the motion of the magnet. For brake applications that require high force density, melt-textured YBCO is a clear choice of material for the magnet because it can carry high currents at a given field and temperature, and is inherently capable of operating in persistent current mode. We present calculations of the performance of this type of brake as a function of magnet current density for catch tubes composed of aluminum and titanium. These results are validated with low speed (20 m/s) tests. Calculations indicate that melt-textured magnets can decelerate projectiles with a mass of 1 kg from 2000 m/s to rest in distances on the order of 10 m. This suggests that this type of brake is suitable for use in hypervelocity experiments, which sometimes requires nondestructive deceleration of projectiles for diagnostic purposes.

  9. CFD Analysis of Automotive Ventilated Disc Brake Rotor

    Directory of Open Access Journals (Sweden)

    Amol V. More

    2014-04-01

    Full Text Available Disc brakes work on the principle of friction by converting kinetic energy into heat energy. The key objective of a disc brake rotor is to accumulate this heat energy and dissipate it immediately. The effect of rotational speed on the aero-thermal performance is assessed. The rotor speed is observed to have substantial effect on the rotor performance. The heat dissipation and thermal performance of ventilated brake discs intensely be influenced by the aerodynamic characteristics of the air flow through the rotor passages. In order to investigate the aero-thermal performance of the ventilated disc brake at several altered driving speeds of the vehicle, the simulations were carried out at 3 different rotational speeds of 44rad/s 88 rad/s and 120 rad/s. The semi-automatic geometric model is created using the package Solid Works and the mesh for the model is done using ICEM CFD and the Post processing of the results is done using FLUENT-14.5.The results are discussed and presented in detail.

  10. ANALYSIS OF FAILURE MECHANISM IN MULTIPLE DISC WET BRAKES

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    By the numberical calculation of dynamic lining pressure distributions,temperature fields and thermal stress fields of steel plates,a method using nonlinear finite element techniques to analyze failure mechanism of a multiple disc wet brake is detailed ,and some measures for combatting these failures are provided.

  11. Non-resonant magnetic braking on JET and TEXTOR

    DEFF Research Database (Denmark)

    Sun, Y.; Liang, Y.; Shaing, K.C.;

    2012-01-01

    The non-resonant magnetic braking effect induced by a non-axisymmetric magnetic perturbation is investigated on JET and TEXTOR. The collisionality dependence of the torque induced by the n = 1, where n is the toroidal mode number, magnetic perturbation generated by the error field correction coil...

  12. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    Science.gov (United States)

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-12-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in obtaining their estimates of these quantities before and after watching a video recording of a car braking from various initial speeds to a complete stop and subsequent application of mathematical statistics to the obtained sets of students' answers. The results revealed that the difference between the value of the car braking distance estimated before watching the video and the real value of this distance was not caused by a random error but by a systematic error which was due to the incorrect students' conceptions about the car braking process. Watching the video significantly improved the students' estimates of the car braking distance, and we show that in this case, the difference between the estimated value and the real value of the car braking distance was due only to a random error, i.e. the students' conceptions about the car braking process were corrected. Some of the students subsequently performed video analysis of the braking processes of cars of various brands and under various conditions by means of Tracker that gave them exact knowledge of the physical quantities, which characterize a motor vehicle braking. Interviewing some of these students brought very positive reactions to this novel method of learning.

  13. SPECIFICITY AND TRENDS IN IMPROVEMENT OF TRACTOR TRAIN BRAKING DYNAMICS

    Directory of Open Access Journals (Sweden)

    G. A. Tayanovsky

    2015-01-01

    Full Text Available The paper considers an important problem in improvement of  braking dynamics potential as part of the overall tractor train dynamics consisting of  an all-wheel drive tractor and heavy-duty trailers which are either locally manufactured or developed with the participation of the paper’s authors. The trailers have a mechanical drive for their wheels from the tractor engine. The trains are intended for transportation peat, organic fertilizers and various loads in  forest exploitation and under other complicated soil and climatic and road conditions where there is justified necessity to activate the trailer wheels.Methodological tools have been developed with the purpose to analyze an influence of the blocked inter-double-reduction axle drive of an active tractor train on distribution of braking forces in double-reduction axles with due account of the heavy-duty peat trailer specificity. Theoretical provisions for wheeled vehicles have been developed with regard to the braking application specificity of active tractor trains with mechanical multi-path drive for wheels of a multi-double-reduction axle propulsion device. The paper presents calculation and theoretical data in order to estimate  distribution of specific braking forces in the double-reduction axle links of the active tractor train when the blocked inter-double-reduction axle drive of the tractor and trailer wheels is switched on and also in the case when the tractor engine is involved in braking process and a clutch coupling is switched-on.Sequence of the calculation formula has been completely carried out in the paper. They represent clear design and operational parameters of the active tractor train. Such approach has made it possible to realize them in the form of a software application which is convenient for analysis of the braking process pertaining to the investigated objects in order to select means for improvement of braking dynamics, rational parameters of multi

  14. 基于毫米波雷达的露天矿卡车防追尾自动刹车系统研究%Research on anti-rear auto brake system of trucks based on millimeter wave radar in Open-pit Mine

    Institute of Scientific and Technical Information of China (English)

    王有仓

    2016-01-01

    This article expounds the principle of signal receiving and transmitting base on technology of millimeter wave radar, introduces the composition of radar collision prevention system and auto brake function for open-pit mine truck. Through the industrial experiment and analysis of mine site, the mine provides the safe distance determination criterion under different road conditions for trucks. The mine applies the millimeter wave radar technology to the mine production practice and provides advanced technical means and methods for safety production.%阐述了毫米波雷达技术的信号收发原理,介绍了露天矿卡车雷达防追尾系统的组成与自动刹车功能。通过矿山现场的工业实验和分析,为卡车提供了在不同道路条件下的安全距离确定准则,将毫米波雷达技术应用到矿山生产实践,为安全生产提供了先进的技术手段和方法。

  15. A low cost, light weight cenosphere–aluminium composite for brake disc application

    Indian Academy of Sciences (India)

    V Saravanan; P R Thyla; S R Balakrishnan

    2016-02-01

    The commonly used composite material for brake rotor consists of silicon carbide (SiC) or aluminium oxide (Al$_2$O$_3$) particles which are more expensive. The weight of conventionally used composite is more compared to base alloy. The aim of this paper is to develop a light weight material for brake disc applications thereby substituting base alloy and conventional composite. This analysis led to 10 vol% cenosphere reinforced aluminium alloy (AA) 6063 composite as the most appropriate material for brake disc. To ensure the manufacturability of composite, composite brake rotor was casted using the sand casting technique and was machined to achieve the final component. Thermal capability of brake disc was ensured by studying temperature variation through vehicle testing procedure of disc brake. Cost reduction is one of the important benefit acquired using cenosphere reinforced composite. This was ensured by cost estimation and analysis. The cost estimated to manufacture the AA6063 brake disc was compared with composite cost.

  16. Thermo-Mechanical Simulation of Brake Disc Frictional Character by Moment of Inertia

    Directory of Open Access Journals (Sweden)

    Fei Gao

    2014-01-01

    Full Text Available The distribution of temperatures gradient and thermal stress of brake disc has been simulated by FEM code to make brake disc thermal stress more homogenously. In this study, using moment of inertia to simulate the realistic brake process instead of theoretically predefines the train deceleration rate, nonlinear deceleration rate and thermo-mechanical behavior has been revealed. The FEM models build upon LS-DYNA® thermo-mechanical code and contact algorithm. Non-uniform temperature alone disc radial direction was caused by severe friction in short time and the low heat transfer coefficient of its material. Parametric analysis for disc brakes have been carried out by comparison of grouped brake applications conform to UIC code, the main factor cause the high temperature gradient and thermal stress of brake disc is brake force and its initial speed.

  17. Selecting and investigating drive of safety brakes on hoists used in shaft sinking

    Energy Technology Data Exchange (ETDEWEB)

    Tsymbal, V.S.; Dimashko, A.D.; Samus, R.M.

    1980-12-01

    The most popular system of driving brakes is with the TEhG electrohydraulically driven pusher. Design of the pusher is described. Tests aimed at determining the most efficient method of cooling oil used in the hydraulic system in the pusher are evaluated. Investigations show that without cooling the oil the pusher can operate continuously 150 minutes long when air temperature is 25/sup 0/C and 100 minutes long when the temperature is 40/sup 0/C. Using an air radiator or a system of cooling oil with an oil radiator is inefficient. It is suggested that using powerful air fans with a capacity of at least 500 M/sup 3//min is the most efficient method of cooling oil in electrohydraulic pushers of safety brakes used in hoists. In order to prevent the oil temperature from increasing to over 90/sup 0/C (90/sup 0/C is the critical level) an automated control system should be used, which switches the pusher off when the temperature increases to 90/sup 0/C. (In Russian)

  18. Synthesis and Characterization of Antifriction Magnetorheological Fluids for Brake

    Directory of Open Access Journals (Sweden)

    Chiranjit Sarkar

    2013-07-01

    Full Text Available Magnetorheological (MR fluids are smart materials with shear strength ranging between zero to 100 kPa under the influence of magnetic field. The present paper discusses the synthesis of MR fluid and its application in brake. In MR brake, gap between stator and rotor is filled with low (off-state viscosity MR fluid. On the application of magnetic field, MR fluid changes its state from liquid to semi-solid by aligning magnetic particles in chains. Due to such chaining action, yield strength of fluid increases, friction between stator and rotor increases and fulfils the braking function. The strength of magnetic particle is a function of relative speed between stator and rotor, applied magnetic field, and volume percentage of magnetic particle. In this study antifriction (off-state and strong chain (on-state CI based MR fluid has been prepared by mixing oleic acid as antifriction additives and tetramethylammonium hydroxide as surfactant to reduce the agglomeration of the MR fluid. Yield strengths of the synthesized MR fluid in on-state and off-state have been compared with commercially available MRF 241ES fluid. A flywheel based MR brake experimental setup has been developed to analyze the performance of designed and developed MR brake.Results show that synthesized MR fluid is stronger and faster in response compared to MRF 241ES fluid.Defence Science Journal, 2013, 63(4, pp.408-412, DOI:http://dx.doi.org/10.14429/dsj.63.2633

  19. Cost-effectiveness criterion for optimal firing at surface targets by MLRS unguided rockets with ballistic aerodynamic brakes

    Directory of Open Access Journals (Sweden)

    Tugomir R. Kokelj

    2011-07-01

    Full Text Available A problem of selecting an artillery target while firing from a multiple launch rocket system (MLRS is not considered frequently in literature. A solution to that problem involves a good agreement among many elements such as shooting dispersion law of distribution, destruction target laws, dimensions of target, and the rate of fire. In this paper, the problem is discussed only for a 128 mm multiple launch rocket system (MLRS M77, known as 'OGANJ', with an unguided wrap around low-spin stabilized rockets with deflectors - aerodynamic brakes for ballistic trajectory control. The paper considered the advantages and disadvantages of the brakes in live fire using the proximity artillery service methodology.

  20. METHODS OF EFFICIENT MONITORING RATE OF THE MOBILE AGRICULTURAL EQUIPMENT BRAKE SYSTEM Методы опредления рациональной периодичности контроля технического состояния тормозной системы мобильной сельскохозяйственной техники

    Directory of Open Access Journals (Sweden)

    Byshоv N. V.

    2013-02-01

    Full Text Available The article presents the methods of efficient monitoring rate of the mobile agricultural equipment brake system based on the usage of methods of the theory of relativity. We have considered the methods of the brake gear monitoring rate according to the acceptable level of reliability, to the technical index and change logic of the technical parameters state and economic-probabilistic method. From the above-stated one can see, first, that diagnosing usage is the development of maintenance preventive strategy. Second, its practicability and the ways of realization are determined by technical and economic calculations

  1. A device of Emergency Braking Designed in Case of Mistakenly Trampling Throttle%一种驾驶员误踩油门紧急制动装置

    Institute of Scientific and Technical Information of China (English)

    王俊华; 张开明; 张力

    2012-01-01

    A device of emergency Braking is designed when a car driver mistakenly trample the throttle. The hardware consist of PIC12C508 microcontroller, acceleration sensor and driver modules, fuel control system, braking control system and so on; When braking mistakenly is tested by the acceleration sensor, piston of the broken oil type electromagnetic valve cut off oil. Then electrical equipment and brake pedal promote the automatic braking; This device can timely judge the wrong operation, and take effective measures to improve the efficiency of braking, which also enhance the safety and have a good practical value.%设计一种防止汽车驾驶员误踩油门紧急纠错装置;硬件由PIC12C508单片机、加速度传感器及驱动模块、油路切断控制系统、辅助刹车制动控制系统等组成;当加速度传感器检测到驾驶员将油门当刹车误踩、施加在油门踏板上的力远大于120N以上时,断油式电磁阀的活塞切断汽车油路,继电器联动刹车踏板进行自动刹车;该装置能及时地判断误操作,并采取有效地制动措施,提高了行车的安全性,有较好的实用价值.

  2. Regenerative braking potencial and energy simulations for a plug-in hybrid electric vehicle under real driving conditions

    OpenAIRE

    Martins, Luís Barreiros; Brito, J. M. O.; Rocha, A. M. D.; Martins, Jorge

    2009-01-01

    There are several possible configurations and technologies for the powertrains of electric and hybrid vehicles, but most of them will include advanced energy storage systems comprising batteries and ultra-capacitors. Thus, it will be of capital importance to evaluate the power and energy involved in braking and the fraction that has the possibility of being regenerated. The Series type Plug-in Hybrid Electric Vehicle (SPHEV), with electric traction and a small Internal Co...

  3. Real-time monitoring of brake shoe keys in freight cars

    Institute of Scientific and Technical Information of China (English)

    Rong ZOU; Zhen-ying XU; Jin-yang LI; Fu-qiang ZHOU

    2015-01-01

    Condition monitoring ensures the safety of freight railroad operations. With the development of machine vision technology, visual inspection has become a principal means of condition monitoring. The brake shoe key (BSK) is an important component in the brake system, and its absence will lead to serious accidents. This paper presents a novel method for automated visual inspection of the BSK condition in freight cars. BSK images are first acquired by hardware devices. The subsequent in-spection process is divided into three stages:first, the region-of-interest (ROI) is segmented from the source image by an im-proved spatial pyramid matching scheme based on multi-scale census transform (MSCT). To localize the BSK in the ROI, cen-sus transform (CT) on gradient images is developed in the second stage. Then gradient encoding histogram (GEH) features and linear support vector machines (SVMs) are used to generate a BSK localization classifier. In the last stage, a condition classifier is trained by SVM, but the features are extracted from gray images. Finally, the ROI, BSK localization, and condition classifiers are cascaded to realize a completely automated inspection system. Experimental results show that the system achieves a correct inspection rate of 99.2%and a speed of 5 frames/s, which represents a good real-time performance and high recognition accuracy.

  4. Brake caliper with offset pads: Innovative brake technology for commercial vehicles offers opportunities to reduce weight and cost; Bremssattel mit tangential versetzten Bremsbelaegen: Innovative Radbremsentechnologie fuer Nutzfahrzeuge bietet neue Moeglichkeiten zur Gewichts- und Kostenreduzierung

    Energy Technology Data Exchange (ETDEWEB)

    Antony, P.; Blatt, P. [WABCO Radbremsen GmbH, Mannheim (Germany)

    2005-07-01

    Continuous optimizations and technical improvements showed no further potential for cost and weight reductions on basis of the conventional technique of a sliding caliper and two supported pads in the carrier. Additionally, global and technical needs are growing. With its 4th generation of air disc brakes and a new caliper concept, WABCO accounts to these developments. Characteristically for the New Generation (NG) is the caliper concept with pad offset in circumferential direction. This presentation describes construction and basics of the system, shows the usage of FEM and elements of Bionic methods and proofs its effectiveness with test bench results. Additional potential for the design of a new interfaces between brake and axle are identified. A significant improved disc cracking behavior offers possibilities for additional cost and weight savings. (orig.)

  5. Study on the dynamic characteristics of a high frequency brake based on giant magnetostrictive material

    Science.gov (United States)

    Xu, Ai Qun

    2016-06-01

    In order to meet the requirements of rapid and smooth braking, high-frequency braking using a giant magnetostrictive actuator is proposed, which can solve the problems in hydraulic braking, such as, it leaks easily, catches fire easily, is difficult to find failures, high cost on maintenance and repairing, etc. The main factors affecting the force of a high-frequency braking actuator are emphatically analyzed, the brakes dynamic model is established and a performance testing device for high frequency braking is constructed based on LabVIEW. The output force of the actuator increases with the excitation current of the driving coil increasing, and the increased multiple of the output force is greater than that of the excitation current; the range of the actuator force amplitude is 121.63 N ∼ 158.14 N, which changes little, while excitation frequency changes between 200 Hz ∼ 1000 Hz. In a minor range of pre-stress, the output force decreases with an increase in the axial pre-stress of the giant magnetostrictive rod, but is not obvious. It is known by finite element simulation analysis that high-frequency braking shortens the braking displacement and time effectively, which proves the feasibility and effectiveness of high frequency braking. Theoretical analysis and experimental results indicate that the output force of the actuator changes at the same frequency with excitation current; it is controllable and its mechanical properties meet the requirements of high frequency braking.

  6. Research of Braking Energy Recovery Control Algorithm Based on Single Wheel Bench%基于单轮台架制动能量回收控制算法的研究

    Institute of Scientific and Technical Information of China (English)

    刘喜明; 孙仁云; 张霞

    2011-01-01

    Electric vehicle can provide a good braking performance under braking,while energy recovery can be guaranteed is an important feature for the electric vehicle control system.We propose a control algorithm which takes single-wheel ABS brake in our laboratory as the prototype bench,which can allocate the relationship between the braking force and the electronic brake force properly,and meanwhile,the braking energy recovery is also considered when the electric vehicle is under braking.It can make the electric vehicle has a good economic fitness in the premise of getting a safety brake,which has an important practical significance to extend driving range of electric vehicles.%电动汽车在制动情况下提供一个良好制动性能的同时保证其能进行能量回收是电动汽车能量回收控制系统的一个重要特性。针对此特性,以本实验室的单轮ABS制动台架为原型,提出了一套控制算法,不仅合理地分配了制动器制动力和电机制动力之间的关系,而且顾及到了制动时进行制动能量回收的问题,使得电动汽车在获得制动安全性的前提下有一个良好的经济适用性,这对延长电动汽车的续驶里程有着重要的实际意义。

  7. Assessing the effects of timing irregularities on radio pulsars anomalous braking indices

    Science.gov (United States)

    Chukwude, A. E.; Chidi Odo, Finbarr

    2016-10-01

    We investigate the statistical effects of non-discrete timing irregularities on observed radio pulsar braking indices using correlations between the second derivative of the measured anomalous frequency (̈νobs) and some parameters that have been widely used to quantify pulsar timing fluctuations (the timing activity parameter (A), the amount of timing fluctuations absorbed by the cubic term (σR23) and a measure of pulsar rotational stability (σz)) in a large sample of 366 Jodrell Bank Observatory radio pulsars. The result demonstrates that anomalous braking indices are largely artifacts produced by aggregations of fluctuations that occur within or outside the pulsar system. For a subsample of 223 normal radio pulsars whose observed timing activity appeared consistent with instabilities in rotation of the underlying neutron stars (or timing noise) over timescales of ˜ 10 – 40 yr, |̈νobs| strongly correlates (with correlation coefficient |r| ˜ 0.80 – 0.90) with the pulsar timing activity parameters and spin-down properties. On the other hand, no meaningful correlations (r objects, whose timing activity appears significantly dominated by white noise fluctuations. The current result can be better understood if the timing noise in isolated pulsars originates from intrinsic spin-down processes of the underlying neutron stars, but white noise fluctuations largely arise from processes external to the pulsar system.

  8. Assessment of the reproducibility of performance testing on an air-braked cycle ergometer.

    Science.gov (United States)

    Palmer, G S; Dennis, S C; Noakes, T D; Hawley, J A

    1996-05-01

    The purposes of this study were (I) to assess the reproducibility of endurance performance testing on an air-braked cycle ergometer, and (II) to compare laboratory performances to performances in road races. Ten well-trained, competitive cyclists (peak power output [PPO] 443 +/- 37 W, [values are mean +/- SD]) undertook either: (I) three 20 km and three 40 km time trials (TT) on an air braked ergometry system (Kingcycle) (n = 6), and/or (II) three 40 km laboratory TT and two 40 km road TT competitions (n = 8). The time taken for the laboratory simulated 20 km and 40 km TT rides were highly reproducible (coefficient of variation 1.1 +/- 0.9% and 1.0 +/- 0.5%, respectively). However, the mean power output and heart rate were significantly different (p cycling time and the average sustained power output. A significant correlation (r = 0.98, p road race times, although road race times were, on average, some 8% slower. These findings indicate that the Kingcycle ergometry system can be used as a reliable method of assessing short term endurance cycling performance.

  9. Can non-ideal magnetohydrodynamics solve the magnetic braking catastrophe?

    CERN Document Server

    Wurster, James; Bate, Matthew R

    2015-01-01

    We investigate whether or not the low ionisation fractions in molecular cloud cores can solve the `magnetic braking catastrophe', where magnetic fields prevent the formation of circumstellar discs around young stars. We perform three-dimensional smoothed particle non-ideal magnetohydrodynamics (MHD) simulations of the gravitational collapse of one solar mass molecular cloud cores, incorporating the effects of ambipolar diffusion, Ohmic resistivity and the Hall effect alongside a self-consistent calculation of the ionisation chemistry assuming 0.1 micron grains. When including only ambipolar diffusion or Ohmic resistivity, discs do not form in the presence of strong magnetic fields, similar to the cases using ideal MHD. With the Hall effect included, disc formation depends on the direction of the magnetic field with respect to the rotation vector of the gas cloud. When the vectors are aligned, strong magnetic braking occurs and no disc is formed. When the vectors are anti-aligned, a disc with radius of 13AU ca...

  10. Tearing mode velocity braking due to resonant magnetic perturbations

    Science.gov (United States)

    Frassinetti, L.; Menmuir, S.; Olofsson, K. E. J.; Brunsell, P. R.; Drake, J. R.

    2012-10-01

    The effect of resonant magnetic perturbations (RMPs) on the tearing mode (TM) velocity is studied in EXTRAP T2R. Experimental results show that the RMP produces TM braking until a new steady velocity or wall locking is reached. The braking is initially localized at the TM resonance and then spreads to the other TMs and to the rest of the plasma producing a global velocity reduction via the viscous torque. The process has been used to experimentally estimate the kinematic viscosity profile, in the range 2-40 m2 s-1, and the electromagnetic torque produced by the RMP, which is strongly localized at the TM resonance. Experimental results are then compared with a theoretical model which gives a reasonable qualitative explanation of the entire process.

  11. Differential Rotation in Neutron Stars Magnetic Braking and Viscous Damping

    CERN Document Server

    Shapiro, S L

    2000-01-01

    Diffferentially rotating stars can support significantly more mass in equilibrium than nonrotating or uniformly rotating stars, according to general relativity. The remnant of a binary neutron star merger may give rise to such a ``hypermassive'' object. While such a star may be dynamically stable against gravitational collapse and bar formation, the radial stabilization due to differential rotation is likely to be temporary. Magnetic braking and viscosity combine to drive the star to uniform rotation, even if the seed magnetic field and the viscosity are small. This process inevitably leads to delayed collapse, which will be accompanied by a delayed gravitational wave burst and, possibly, a gamma-ray burst. We provide a simple, Newtonian, MHD calculation of the braking of differential rotation by magnetic fields and viscosity. The star is idealized as a differentially rotating, infinite cylinder consisting of a homogeneous, incompressible conducting gas. We solve analytically the simplest case in which the ga...

  12. Magnetic Braking and Protostellar Disk Formation: The Ideal MHD Limit

    Science.gov (United States)

    Mellon, Richard R.; Li, Zhi-Yun

    2008-07-01

    Magnetic fields are usually considered dynamically important in star formation when the dimensionless mass-to-flux ratio is close to, or less than, unity (λ lesssim 1). We show that, in disk formation, the requirement is far less stringent. This conclusion is drawn from a set of 2D (axisymmetric) simulations of the collapse of rotating, singular isothermal cores magnetized to different degrees. We find that a weak field corresponding to λ ~ 100 can begin to disrupt the rotationally supported disk through magnetic braking, by creating regions of rapid, supersonic collapse in the disk. These regions are separated by one or more centrifugal barriers, where the rapid infall is temporarily halted. The number of centrifugal barriers increases with the mass-to-flux ratio λ. When λ gtrsim 100, they merge together to form a more or less contiguous, rotationally supported disk. Even though the magnetic field in such a case is extremely weak on the scale of dense cores, it is amplified by collapse and differential rotation, to the extent that its pressure dominates the thermal pressure in both the disk and its surrounding region. For relatively strongly magnetized cores with λ lesssim 10, the disk formation is suppressed completely, as found previously. A new feature is that the mass accretion is highly episodic, due to reconnection of the magnetic field lines accumulated near the center. For rotationally supported disks to appear during the protostellar mass accretion phase of star formation in dense cores with realistic field strengths, the powerful magnetic brake must be weakened, perhaps through nonideal MHD effects. Another possibility is to remove, through protostellar winds, the material that acts to brake the disk rotation. We discuss the possibility of observing a generic product of the magnetic braking, an extended circumstellar region that is supported by a combination of toroidal magnetic field and rotation—a "magnetogyrosphere"—interferometrically.

  13. Analysis of natural frequency variability of a brake component

    Science.gov (United States)

    Gallina, A.; Lisowski, W.; Pichler, L.; Stachowski, A.; Uhl, T.

    2012-10-01

    The manufacture of automotive disc brake calipers is subjected to many inherent variabilities resulting in product variability. In particular, the dispersion of natural frequency values is a primary issue in the context of vehicle comfort. This paper aims to quantify natural frequency variability and search for its causes. Extensive experimental tests and numerical simulations, described in the paper, point out the fundamental role of mold wear and assembling process in this variability.

  14. Differential Rotation in Neutron Stars: Magnetic Braking and Viscous Damping

    OpenAIRE

    Shapiro, Stuart L.

    2000-01-01

    Diffferentially rotating stars can support significantly more mass in equilibrium than nonrotating or uniformly rotating stars, according to general relativity. The remnant of a binary neutron star merger may give rise to such a ``hypermassive'' object. While such a star may be dynamically stable against gravitational collapse and bar formation, the radial stabilization due to differential rotation is likely to be temporary. Magnetic braking and viscosity combine to drive the star to uniform ...

  15. The effects of porosity in friction performance of brake pad using waste tire dust

    Directory of Open Access Journals (Sweden)

    İbrahim Mutlu

    2015-10-01

    Full Text Available Abstract This research is focused on the effect of porosity on the friction-wear properties of automotive brake pads. Waste Tire Dust (WTD was used as a new friction material in brake pads. Newly formulated brake pad materials with five different components have been produced by conventional techniques. In the experimental studies, the change of the friction coefficient, the temperature of the friction surface, the specific wear rate, and the hardness, density and porosity were measured. In addition, the micro-structural characterizations of brake pads are determined using Scanning Electron Microscopy (SEM. The mean coefficient of friction, porosity and specific wear are increased due to a WTD rate increases, on the other hand, hardness and density are decreased. As a result, WTD can be considered as an alternative to revalorize this kind of waste products in the brake pads and the amount of porosity of the brake pad affected the friction coefficient and wear behavior of the pad.

  16. 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.

  17. The Braking Index of Radio-quiet Gamma-ray Pulsar

    CERN Document Server

    Clark, C J; Wu, J; Guillemot, L; Camilo, F; Johnson, T J; Kerr, M; Allen, B; Aulbert, C; Beer, C; Bock, O; Cuéllar, A; Eggenstein, H B; Fehrmann, H; Kramer, M; Machenschalk, B; Nieder, L

    2016-01-01

    We report the discovery and timing measurements of PSR J1208-6238, a young and highly magnetized gamma-ray pulsar, with a spin period of 440 ms. The pulsar was discovered in gamma-ray photon data from the Fermi Large Area Telescope (LAT) during a blind-search survey of unidentified LAT sources, running on the distributed volunteer computing system Einstein@Home. No radio pulsations were detected in dedicated follow-up searches with the Parkes radio telescope, with a flux density upper limit at 1369 MHz of 30 $\\mu$Jy. By timing this pulsar's gamma-ray pulsations, we measure its braking index over five years of LAT observations to be $n = 2.598 \\pm 0.001 \\pm 0.1$, where the first uncertainty is statistical and the second estimates the bias due to timing noise. Assuming its braking index has been similar since birth, the pulsar has an estimated age of around 2,700 yr, making it the youngest pulsar to be found in a blind search of gamma-ray data and the youngest known radio-quiet gamma-ray pulsar. Despite its you...

  18. Modeling the Exo-Brake and the Development of Strategies for De-Orbit Drag Modulation

    Science.gov (United States)

    Murbach, M. S.; Papadopoulos, P.; Glass, C.; Dwyer-Cianciolo, A.; Powell, R. W.; Dutta, S.; Guarneros-Luna, A.; Tanner, F. A.; Dono, A.

    2016-01-01

    The Exo-Brake is a simple, non-propulsive means of de-orbiting small payloads from orbital platforms such as the International Space Station (ISS). Two de-orbiting experiments with fixed surface area Exo-Brakes have been successfully conducted in the last two years on the TechEdSat-3 and -4 nano-satellite missions. The development of the free molecular flow aerodynamic data-base is presented in terms of angle of attack, projected front surface area variation, and altitude. Altitudes are considered ranging from the 400km ISS jettison altitude to 90km. Trajectory tools are then used to predict de-orbit/entry corridors with the inclusion of the key atmospheric and geomagnetic uncertainties. Control system strategies are discussed which will be applied to the next two planned TechEdSat-5 and -6 nano-satellite missions - thus increasing the targeting accuracy at the Von Karman altitude through the proposed drag modulation technique.

  19. Research of blended braking characteristics of super-big electric wheels of mining dump truck%特大型电动轮矿用自卸车联合制动特性研究

    Institute of Scientific and Technical Information of China (English)

    罗春雷; 钟锡继; 吴伟传

    2012-01-01

    In order to obtain the blended braking characteristics of super-big electric wheels of mining dump truck on different downhill slope, and analyze the power distribution between grid resistance electric dynamic brake and hydraulic wet multi-disc brake, the dynamic model of blended braking system was established by using a certain type of 520 tons gross vehicle weight dump truck as research object. Results show that with the initial velocity of 30 km/h, emergency braking distance is less than 21 m on different slopes below 10% ; the average specific brake force nearly remain unchanged on different slope, and the maximum value is about 0. 35; for rear specific brake force is bigger than that of front, the possibility of sideslip and deviation is bigger than that of out of steering control; the specific brake force difference between rear and front can be reduced by moving the center of gravity to the rear axle, while the average specific brake force remain unchanged, so the ground adhesion can used effectively; the brake power ratio between grid resistance and wet multi-disc brake is about 2- 3. These results shows that the blended braking system can reduce the brakes load effectively, increase braking performance, and extend the service life of the main brakes.%为了研究特大型电动轮矿用自卸车下坡联合制动时的制动特性,分析联合制动时电阻栅能耗制动及液压多片湿盘式制动器制动功率的分配,以湘电重装满载整车重量达520t的自卸车为研究对象,建立了自卸车电阻栅能耗制动及液压多片湿盘式制动器联合制动系统动力学模型,利用Mtlab/simulink对该自卸车在不同下坡坡道上的紧急联合制动进行了数值分析计算,获得制动特性曲线.结果表明:初速度为30 km/h时,在不高于10%的坡度下紧急制动距离不超过21 m;平均比制动力在不同坡道基本保持不变,最高值为0.35左右;后轮比制动力大于前轮比制动力,侧滑、跑

  20. Detecting groan sources in drum brakes of commercial vehicles by TVA-FMEA

    OpenAIRE

    Karabay, Sedat; Baynal, Kasim; İğdeli, Cengiz

    2015-01-01

    In this article, the strategy followed by an automobile company for detecting the root causes of groan complaints related to rear drum brakes in commercial vehicles is presented using data collected from the sold troubled vehicles and from new vehicles from the production line, as well as the drum-brake test rig at the laboratory. Drum brake groan is often very intense and can cause large numbers of customer complaints. During a groan noise event, vehicle structure and suspension components a...