Integrated Active Suspension and Anti-Lock Braking Control for Four-Wheel-Independent-Drive Electric Vehicles

This paper presents an integrated control scheme for enhancing the ride comfort and handling performance of a four-wheel-independent-drive electric vehicle through the coordination of active suspension system(ASS)and anti-lock braking system(ABS).First,a longitudinal-vertical coupled vehicle dynamics model is established by integrating a road input model.Then the coupling mechanisms between longitudinal and vertical vehicle dynamics are analyzed.An ASS-ABS integrated control system is proposed,utilizing an H∞controller for ASS to optimize load transfer effect and a neural network sliding mode control for ABS implementation.Finally,the effectiveness of the proposed control scheme is evaluated through comprehensive tests conducted on a hardware-in-loop(HIL)test platform.The HIL test results demonstrate that the proposed control scheme can significantly improve the braking performance and ride comfort compared to conventional ABS control methods.

Application Research on Self-healing Technology with Microcapsules for Automobile Brake Pad

In order to improve the performance of non-asbestos composite auto brake pads that are composed of matrix resin, reinforced material and fillers, a novel method with new technology of self-heal microcapsules was proposed. Nano reinforced fillers＇ effects were also considered in the experiment project. Five recipe designs for new composite auto brake pads were carried out and cor-responding samples were prepared as well. The friction coefficient and wearing properties at certain temperature, impact intensity and hardness were comparatively studied. Investigations indicate that properties of such composite auto brake pads meet the requirements of the national standards while microcapsule＇s weight content varies from 5.5wt%-1.09wt% of matrix resin and microcapsule＇s loca-tion varies in the pads. Nano reinforced fillers have the effects of increasing composites＇ impact in-tensity and hardness. Application of self-healing microcapsules in auto brake pads is feasible.

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

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） fimction. 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.

Development of a Low-cost Hardware-in-the-loop Simulation System as a Test Bench for Anti-lock Braking System

Nowadays validation of anti-lock braking systems（ABS） relies mainly on a large amount of road tests.An alternative means with higher efficiency is employing the hardware-in-the-loop simulation（HILS） system to substitute part of road tests for designing,testing,and tuning electronic control units（ECUs） of ABS.Most HILS systems for ABS use expensive digital signal processor hardware and special purpose software,and some fail-safe functions with regard to wheel speeds cannot be evaluated since artificial wheel speed signals are usually provided.In this paper,a low-cost ABS HILS test bench is developed and used for validating the anti-lock braking performance and tuning control parameters of ABS controllers.Another important merit of the proposed test bench is that it can comprehensively evaluate the fail-safe functions with regard to wheel speed signals since real tone rings and sensors are integrated in the bench.A 5-DOF vehicle model with consideration of longitudinal load transfer is used to calculate tire forces,wheel speeds and vehicle speed.Each of the four real-time wheel speed signal generators consists of a servo motor plus a ring gear,which has sufficient dynamic response ability to emulate the rapid changes of the wheel speeds under strict braking conditions of very slippery roads.The simulation of braking tests under different road adhesion coefficients using the HILS test bench is run,and results show that it can evaluate the anti-lock braking performance of ABS and partly the fail-safe functions.This HILS system can also be used in such applications as durability test,benchmarking and comparison between different ECUs.The test bench developed not only has a relatively low cost,but also can be used to validate the wheel speed-related ECU design and all its fail-safe functions,and a rapid testing and proving platform with a high efficiency for research and development of the automotive ABS is therefore provided.

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

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.

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

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.

制动装置用碳纤维复合材料耐磨性能表征及影响研究

以环氧树脂和碳纤维为原料,采用模压成型工艺制备了汽车防抱制动装置用碳纤维复合材料,研究了模压压力、加压温度、固化温度和固化时间对碳纤维复合材料摩擦磨损性能的影响,并分析了其摩擦磨损机理。结果表明,当模压压力为10 MPa、加压温度为110℃、固化温度为140℃、固化时间为30 min时,汽车防抱制动装置用碳纤维复合材料的摩擦系数较小,到达磨合期较短,具有良好的耐磨性能,为适宜的模压成型工艺。可以通过调整模压成型工艺参数,制备出耐磨性能良好的汽车防抱制动装置用碳纤维复合材料。

基于灰度图二值化的汽车制动器摩擦片残缺检测方法

由于传统方法在汽车制动器摩擦片残缺检测应用中正检率比较低,无法达到预期的检测效果,提出基于灰度图二值化的汽车制动器摩擦片残缺检测方法。采用CCD工业相机采集到摩擦片图像信息,通过对摩擦片灰度图二值化处理,提取到摩擦片图像前景区域,利用递增函数计算出摩擦片轮廓连通域,提取到摩擦片残缺特征,从而识别检测出摩擦片残缺。经实验证明,设计方法正检率在95%以上,在汽车制动器摩擦片残缺检测方面具有良好的应用前景。

汽车制动器磨损度检测方法的研究现状及优化策略

通过对现有汽车制动器磨损度的检测方式进行分析,探究和改进制动器磨损度的检查方法,以提高制动器的安全性和可靠性。在传统检查方法的基础上,提出增加智能化检测传感器和超声波检测方式的优化策略,并通过可视化技术展示分析结果。此策略在一定程度提高了检测结果的精度,且具有高效率和低成本的优点,并适用于各种车型和制动器类型的检测,极大地提高了汽车制动器磨损程度的检测能力,间接减少汽车故障率,提高驾驶安全性。

进口汽车用制动器衬片摩擦性能检测与产品不合格原因分析

随着国家经济的快速发展和人民对高质量、安全性的生活方向发展,而进口汽车在这一需求下逐年呈上升趋势,其中进口汽车用制动器衬片是汽车制动系统中最关键的安全零件,对制动效果起关键性作用,本文采用取样法对汽车盘式制动器衬片的摩擦性能进行测定和分析,并针对进口汽车用制动器衬片摩擦性能检测不合格原因分析。

电控发动机中汽车防抱死制动系统故障原因分析

本文通过分析电控发动机中汽车防抱死制动系统的工作原理、组成部分和功能,剖析了常见的硬件故障类型,包括电机故障、电路故障、执行机构故障等,并详细探讨了泵模块、排气阀、制动管路故障的成因及检修步骤。分析了ABS控制模块故障、ABS传感器故障以及ABS系统线路故障等方面的根源原因,阐述了各类故障对ABS系统性能的影响,以及相应的检测和修理方法。通过对防抱死制动系统故障成因的全面剖析,强调了深入研究系统故障原因的重要性。

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

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.

基于接触摩擦模型汽车盘式制动器场分布分析

汽车制动器制动过程中温度场、应力场等相互耦合,对系统的可靠性具有重要影响。针对应广泛的盘式制动器开展研究,根据制动原理,对影响会制动的关键参数进行分析,并根据车型参数进行验证。采用接触摩擦模型,对制动器的盘、片的热力耦合特性进行分析,建立数学模型,并采用ABAQUS建立仿真模型。选取紧急制动工况,设置制动初速度,获取各种特性参数场的分布规律,并对热力耦合特性进行分析;搭建盘式制动器性能分析台架,选取相同的紧急制动参数,获取整个制动规程中温度变化规律。结果可知:制动盘片接触的过程为非均匀接触,峰值压力为27.47MPa,最高接触应力为123.2MPa,均满足材料强度的使用要求;试验测试结果最高温度为562℃,出现在整个制动过程的结束前0.9s;仿真与试验测试温度变化趋势一致,且误差小于5%,表明摩擦接触模型分析结果是可靠的,为此类研究提供参考。

汽车木陶瓷制动衬片热弹性耦合分析

提出了一种以木陶瓷为原料的汽车制动衬片,建立了木陶瓷制动衬片的盘式制动器三维模型,模拟多种工况制动时木陶瓷制动衬片作用下盘式制动器的热弹性耦合特性,并基于Archard磨损模型及ABAQUS软件中的UMESHMOTION子程序实现木陶瓷制动衬片磨损深度的数值模拟。结果表明:以木陶瓷材料作为汽车制动摩擦材料,制动过程中制动盘温度峰值为254.25℃,相较于传统金属型制动衬片制动盘温度峰值低9.91℃,应力分布均匀,有利于减少制动盘热裂纹的产生,同时降低制动盘“热衰退”效应对车辆制动效能稳定性的影响。木陶瓷制动衬片制动过程中温度最高可达281.41℃,远低于木陶瓷材料热分解温度,具备良好的可靠性。以木陶瓷作为制动衬片摩擦材料,单次高速紧急制动磨损深度最大不超过2.11μm,具备良好的耐磨性。

基于机器视觉的刹车盘表面缺陷检测技术研究

汽车刹车盘是汽车制动系统的关键部件之一,刹车盘在铸造过程中由于生产工艺、生产环境、人工操作等因素会导致刹车盘存在砂眼、气孔、缩孔、裂纹等多种表面缺陷,从而影响其使用寿命和驾乘安全。随着人工智能技术的发展,机器视觉技术因其鲁棒性强、效率高、致错率低等诸多优点,已被逐步应用于刹车盘表面缺陷检测工序中,刹车盘检测技术也逐步与整个生产过程各工序的设备连接和数据兼容,高集成化的工业控制模式正在实现。随着图像处理技术的进步,相机、工业机器人等硬件设施的不断完善,未来将会逐步实现刹车盘流水线自动检测和缺陷件自动筛选,这将有助于提升刹车盘的生产质量,最大程度地保证车辆及驾乘人员的安全。

基于驾驶行为特性的AEB系统控制策略研究

为提高自动紧急制动系统在城市路况下的适用性,提出了一种基于驾驶行为特性的自动紧急制动系统控制策略。首先搭建驾驶员在环测试实验台,采集不同驾驶员在制动过程中的驾驶数据,分析驾驶行为特性与车辆间相对运动状态之间的关系。然后以分层控制的思想设计一种两级预警与制动控制策略:上层控制器确定制动减速度及预警和制动触发时间阈值,下层控制器设计模糊PID控制器实现对制动主缸压力的控制。最后利用CarSim与Matlab/Simulink进行前车静止场景仿真,并搭建无人驾驶线控底盘测试平台进行半实物实验验证。结果表明:两级预警与制动功能均能有效触发,制动过程中实际制动减速度能够很好地跟随期望制动减速度,且制动完成后车间距均控制在2.15 m左右,体现了设计的AEB系统具有良好的预警和紧急避撞效果。

汽车制动系统故障诊断及维修方法的分析

汽车制动系统是汽车装置中的一部分,只有具备了该系统,才可以保证汽车正常行驶,不过制动系统也会出现故障,这种情况下就会带来一些安全隐患问题,例如刹车不及时,导致交通事故安全问题的概率会提高。为保证汽车每项功能能够得到充分发挥,确保人身安全和财产安全,就需要定期维修汽车制动系统,预先了解故障问题。本文就针对汽车制动系统故障诊断和维修方式进行了分析与论述,以供相关人员参考。

考虑再生制动的线控电制动系统防滑控制策略研究

为顺应汽车电动化、智能化的发展需求,该文提出线控电制动系统,为提高车辆整体制动性能,围绕着整车“利用附着系数最大化”和“能量回收率最大化”的双重目标展开,探究再生制动和摩擦制动混合作用下线控电制动系统的防滑控制策略,主要研究内容为基于四轮制动力分配的动态防滑控制和再生制动能量回收控制。

汽车制动性能检验不合格原因浅析

机动车制动性能检验是汽车安全性检验工作中重要项目之一,也是保障车辆行驶安全方面重要的因素。本文以滚筒反力式制动试验台为例,对机动车安全性能检验中的线内检验制动性能检验的要求、检验过程、影响的主要因数及其它导致不合格的原因做介绍及分析,使机动车检验维修人员真正了解报告单的“内涵”,以便“对症下药”更快捷的找到制动性能检验不合格的因素。

基于PID控制的防抱死制动系统实现研究

为了避免汽车抱死现象的发生,提出一种基于PID控制的汽车防抱死制动系统(ABS)设计方案,该系统可有效提高汽车的行车安全。采用汽车的四分之一作为主要研究对象,建立了合理有效、简单适用的单轮车辆制动系统数据模型,有利于提升汽车的防抱死制动效果,符合系统的精度要求。通过对系统进行仿真可知该系统可实现汽车的防抱死制动,在测试过程中未发生抱死现象,较好地实现了汽车的制动控制。