内置阀门式汽车制动液真空加注头的研制

针对目前国内外制动液加注机在对带ABS汽车制动系统加注制动液时,会因设备内部管路残留的制动液在高真空下气化,从而导致加注机内部真空度降低最终导致汽车制动力下降、制动效果变差的问题,本文采用了一种内置阀门式真空加注头,由PLC通过控制电磁阀来驱动气动阀门的开闭,从根本上解决了这一问题。     

混动汽车制动液加注通讯插头开发浅谈

行车制动系统是整车系统重要组成部分,其中制动液加注作为制动系统装配的最后一道工序,始终是总装车间的一项关键工艺。混动汽车由于其同时保留内燃机系统及电动系统,前舱产品布置复杂拥挤,往往给制动液加注通讯设备的设计开发造成不小的难度。文章归纳总结目前总装制动液加注常用几种的通讯方式,通过对比,提出了一种较经济,针对混动汽车的制动液加注通讯设备设计方法。     

MK20型ABS的排气加液

ＭＫ２０型ＡＢＳ中，由于液压回路中增加了用来调节车轮制动器压力的电磁阀，使得系统的排气加液跟传统的制动系统有所不同。介绍了ＡＢＳ的真空排气加液过程和ＡＢＳ常闭阀控制过程，并对真空加液的操作时间节拍进行估算。试验结果表明，其排气加液效果较好。     

汽车总装线上加注制动液泄漏故障分析

制动液加注系统在汽车生产线上属于装配工艺设备,主要功用是完成汽车制动液的加注。随着汽车生产效率的不断提高,加注节拍也越来越快,一般要求在45~80s内完成制动液的加注。加注过程要求首先对汽车制动系统进行抽真空,使其达到一定真空度时,再将制动液在压力下加入。并要求在抽真空的同时,通过系统真空度的变化来判断制动系统是否有泄漏现象。制动系统真空度大小将直接影响到汽车性能。即使制动液加注线上     

ABS检测与加注技术在生产上对保证汽车制动性能的探讨（三）

制动系统尤其是装用ABS系统的制动系统更要求良好的密封性，同时作为制动系统中传递制动压力的载体——制动液也需要很好的干燥性，整个制动系统要求无空气、无水分、系统密封。因此在制动液加注过程中制动液首先需经过干燥，有足够的沸点，系统真空度则需在2．5mbar以下，这就要求除汽车上制动管路要求高密封外，对加注接头与汽车上储液罐也提出高密封性要求。     

JBUS通讯技术在制动液加注设备上的应用

制动液加注的核心是加注设备和汽车ABS电控单元(ECU)之间的通讯控制问题,神龙公司采用JBUS通讯技术解决了这一问题。ABS通讯控制分为初始化、真空、加注、液面调整四个阶段,四个阶段的控制字分别为30、31、32、和33。本文同时介绍了西门子公司S7-Pdiag故障诊断软件的应用、PROFIBUS总线诊断、Winccflexible软件组态、模拟量信号处理等的应用。     

ABS制动系统排气

ＡＢＳ制动防抱死系统与普通制动系统在结构上有所区别，因此其、调整操作也有所不同。本期主要介绍ＡＢＳ系统排气操作要领，结合典型车的具体构造，说明排气操作程序。     

美国装有ABS汽车的制动器保养：ABS中的空气排除方法

装ＡＢＳ的汽车，若要打开制动管道，拆卸液压部件或整个系统进行修理时，则需进行一些特殊操作，当更换制动器，打开制动管道更换液压部件，或由于管道中出现空气使制动踏板发软或变低时，均应对制动器进行放气。一般放气规则：将管道中的空气放出，接通ＡＢＳ调节器中的电磁阀，使用汽车制造厂规定牌号的制动液，若ＡＢＳ的警告灯亮了，应在系统放气前，先诊断和修理故障。列举了装有不同ＡＢＳ的车型放气实例。     

ABS系统动作及制动液

汽车制动防抱死系统日益广泛的应用在汽车上，其使用维护工作应紧随其后。本文主要介绍ＡＢＳ系统动作原理、保修要点与制动液有关事项。     

“勇士”BJ2022型战地越野车ABS系统故障排除一例

故障现象：一辆“勇士”BJ2022型战地越野车,在野外训练过程中,ABS故障警告灯闪亮,但制动性能未发生显著变化。故障排除：现场试车,发现制动时地面有拖痕,ABS系统失效,但制动系工作正常。检查制动液压系统,发现系统管路及接头密封良好,制动液油质正常,仅液面高度略低。于是加注制动液并进行人工排气,但故障现象依然存在。用ABS故障诊断仪检测,显示左前轮轮速传感器故障,但清除故障码后即显示无故障,     

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

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.     

A practical identifier design of road variations for anti-lock brake system

Emergency brake technologies have always been a major interest of vehicle active safety-related studies. On homogeneous surfaces, traditional anti-lock brake system (ABS) can achieve efficient braking performance and maintain the handling capability as well. However, when road conditions are time variant during the braking process, or different at the bilateral wheels, braking stability performance is likely to be degraded. To address this problem and enhance ABS performances, a practical identifier of road variations is developed in this study. The proposed identifier adopts a statechart-based approach and is hierarchically constructed with a wheel layer and a full vehicle layer identifier. Based on the identification results, modifications are made to a four-phase wheel-behaviour-based ABS controller to enhance its performance. The feasibility and effectiveness of the proposed identifier in collaborating with the modified ABS controller are examined via simulations and further validated by track tests under various practical braking scenarios.     

一种基于PC486微机的实时硬件闭环模拟系统及应用

本文介绍一种基于ＰＣ４８６微机建造的实时硬件闭环模拟系统，用此系统研究并研制了４ＡＢＳ控制器，描述了系统硬件配置及实现的方法，车辆，轮胎及制动器的建模，给出了模拟结果并进行了控制逻辑的分析。     

Experimental investigations on continuous regenerative anti-lock braking system of full electric vehicle

Functions of anti-lock braking for full electric vehicles (EV) with individually controlled wheel drive can be realized through conventional brake system actuating friction brakes and regenerative brake system actuating electric motors. To analyze advantages and limitations of both variants of anti-lock braking systems (ABS), the presented study introduces results of experimental investigations obtained from proving ground tests of all-wheel drive EV. The brake performance is assessed for three different configurations: hydraulic ABS; regenerative ABS only on the front axle; blended hydraulic and regenerative ABS on the front axle and hydraulic ABS on the rear axle. The hydraulic ABS is based on a rule-based controller, and the continuous regenerative ABS uses the gain-scheduled proportional-integral direct slip control with feedforward and feedback control parts. The results of tests on low-friction road surface demonstrated that all the ABS configurations guarantee considerable reduction of the brake distance compared to the vehicle without ABS. In addition, braking manoeuvres with the regenerative ABS are characterized by accurate tracking of the reference wheel slip that results in less oscillatory time profile of the vehicle deceleration and, as consequence, in better driving comfort. The results of the presented experimental investigations can be used in the process of selection of ABS architecture for upcoming generations of full electric vehicles with individual wheel drive.     

Modeling and Analysis of Automotive Antilock Brake Systems Subject to Vehicle Payload Shifting

The steerability and stability of vehicles must be maintained during emergency stopping and evasive driving maneuvers on degraded road surfaces. The introduction of antilock brake and traction control systems (ABS/TCS) has expanded the envelope of safe vehicle operation for the majority of drivers. These mechatronic systems combine an electronic controller with wheel speed sensors, an electro-mechanical hydraulic brake actuator, and in some instances, engine intervention through the engine control unit, to regulate wheel slip. The development of ABS systems has traditionally depended on extensive in-vehicle testing, at cold weather proving grounds, which contribute to lengthy product development cycles. However, recent attention has been focused on the use of simulation and hardware-in-the-loop strategies to emulate test conditions in a controlled setting to shorten product design time and methodically address critical safety issues. In this paper, the effect of transient load shifting due to cargo movement on ABS performance in light-duty vehicles will be investigated. Analytical and empirical mathematical models are presented to describe the chassis, tire/road interface, wheel, brake modulator, and cargo dynamics. Two strategies, a model-free table lookup and model-based discrete nonlinear controller, are presented to regulate the ABS modulator's operation. These vehicle and controller dynamics have been integrated into a simulation tool to investigate the effect of transient weight transfers on the vehicle's overall stopping distance and time. Representative numerical results are presented and discussed to quantify the ABS systems' performance for various loading and operating conditions.     

基于模糊PID的汽车防抱制动系统控制策略的研究

在基于滑移率的ABS控制策略的基础上,建立了11自由度的汽车急转制动仿真模型。提出了一种参数自整定模糊PID控制算法,并采用了Bang-Bang控制和模糊PID控制分别对汽车ABS进行了仿真,其结果表明:模糊PID控制比Bang-Bang控制可以达到更好的效果。     

Improvement of drivability and fuel economy with a hybrid antiskid braking system in hybrid electric vehicles

When braking on wet roads, Antilock Braking System (ABS) control can be triggered because the available brake torque is not sufficient. When the ABS system is active, for a hybrid electric vehicle, the regenerative brake is switched off to safeguard the normal ABS function. When the ABS control is terminated, it would be favorable to reactivate the regenerative brake. However, recurring cycles from ABS to motor regenerative braking could occur. This condition is felt to be unpleasant by the driver and has adverse effects on driving stability. In this paper, a novel hybrid antiskid braking system using fuzzy logic is proposed for a hybrid electric vehicle that has a regenerative braking system operatively connected to an electric traction motor and a separate hydraulic braking system. This control strategy and the method for coordination between regenerative and hydraulic braking are developed. The motor regenerative braking controller is designed. Control of regenerative and hydraulic braking force distribution is investigated. The simulation and experimental results show that vehicle braking performance and fuel economy can be improved and the proposed control strategy and method are effective and robust.     

Automotive Steering Control in a Split-µ Manoeuvre Using an Observer-Based Sliding Mode Controller

Summary In this paper a sliding mode integral action controller and sliding mode observer are used to enhance vehicle stability in a split- µ manoeuvre. Anti-lock braking systems (ABS) have become an integral part of modern cars, and they have dramatically improved vehicle handling in braking manoeuvres. However, when a vehicle attempts to brake on a surface with uneven friction coefficient such as on wet or icy roads, a so-called split- µ scenario, the yaw moment generated by the asymmetric braking can prove demanding for an inexperienced driver. The controller presented hereworks in conjunction with a conventional ABS system to provide safe and effective braking through steer-by-wire. This paper extends previous state-feedback work by only using certain measurable quantities in the controller, estimating further signals by employing an observer.     

Automotive Steering Control in a Split-µ Manoeuvre Using an Observer-Based Sliding Mode Controller

Summary In this paper a sliding mode integral action controller and sliding mode observer are used to enhance vehicle stability in a split- µ manoeuvre. Anti-lock braking systems (ABS) have become an integral part of modern cars, and they have dramatically improved vehicle handling in braking manoeuvres. However, when a vehicle attempts to brake on a surface with uneven friction coefficient such as on wet or icy roads, a so-called split- µ scenario, the yaw moment generated by the asymmetric braking can prove demanding for an inexperienced driver. The controller presented hereworks in conjunction with a conventional ABS system to provide safe and effective braking through steer-by-wire. This paper extends previous state-feedback work by only using certain measurable quantities in the controller, estimating further signals by employing an observer.     

防抱死制动系统模糊自学习控制研究

由于车辆参数和运行工况的复杂多变，针对特定参数和路面条件所设计的防抱死制动系统往往难以适应。为解决这一问题，文中首先建立了带有盘式制动器的双轮车辆直线制动系统的数学模型；而后提出了模糊自学习控制策略，该方案通过引入模糊学习机制以调整模糊控制器的规则集，可使车辆对象输出跟踪理想参考模型的输出；接着对所设计控制算法在不同路面条件下进行了性能模拟；最后开发了模糊自学习微控制器，基于硬件在环仿真技术，对设计控制器的性能进行了实验验证。