汽车ABS/ASR/ACC集成化系统

叙述了ACC系统和ABS/ASR系统在改善汽车高速行驶主动安全性方面的功用 ,阐述了ACC系统是ABS/ASR系统功能的延伸、逻辑的发展及它们之间的内在联系 ,指出了在ABS/ASR的基础上只需增加测距装置和添加巡航控制子程序 ,就可方便地实现ABS/ASR/ACC集成化系统 ,并给出了集成化系统的控制框图和控制方法 ,论述了ABS/ASR/ACC集成化系统比孤立的ABS/ASR和ACC系统的优越性 .     

混有CACC车辆和ACC车辆的混合交通流驾驶舒适性

为了探索协同自适应巡航控制(cooperative adaptive cruise control,CACC)车辆对交通系统的潜在影响,分析了CACC车辆市场普及过程中存在的CACC车辆、自适应巡航控制(adaptive cruise control,ACC)车辆与人工驾驶车辆混合交通流驾驶舒适性.应用加州伯克利PATH实车验证的ACC模型和CACC模型进行数值仿真实验,采用国际ISO-2631-1标准评价混合交通流舒适性,并对ACC和CACC期望车间时距进行参数敏感性分析.最后,从交通流稳定性的角度,对舒适性仿真结果进行了讨论.结果表明:随着CACC市场率的增加,舒适性呈现先恶化、再逐渐提升的趋势.较大的ACC车间时距有利于抑制舒适性的恶化程度,CACC车辆对舒适性的提升作用不受其车间时距取值的影响.混合交通流稳定性定性地决定了舒适性的变化趋势,人工车辆安装车车通信设备,有助于舒适性的逐渐提升.     

多轴重型汽车气动制动防抱死系统性能仿真与试验

利用Matlab/Stateflow建立了多轴重型汽车气动ABS控制器模型,采用逻辑门限值算法建立ABS控制系统在高、低附着系数路面和对开路面上的控制策略,同时采用预测控制技术给出了相应的控制逻辑。结合重型汽车整车刚弹耦合虚拟样机模型,利用ADAMS和Matlab/Simulink对重型汽车气动ABS系统的制动性能进行联合仿真分析,并把联合仿真结果与实车ABS性能试验结果进行了对比。结果表明所设计的气动ABS控制系统的仿真分析结果与实车试验结果具有较好的一致性。     

Experiment Research on Fine Regulation of Wheel Cylinder Pressure Using PWM Technology

A test bench of ABS/ASR integrated hydraulic system is developed by using pulse-width modulation （PWM） technology. The effective duty ratio range of ABS outlet valve has been tested in PWM control. With 50 Hz carrier wave frequency, the tests are performed to determine the correspondence between duty ratio and the wheel cylinder pressure variation. The duty ratio range of ABS outlet valve in PWM control is determined and an experimental model of pressure reduction velocity （PRV） of wheel cylinder using PWM control is established. By comparison and test of the experimental model and realization of controlling the duty ratio of ABS outlet valves, the fine regulation of wheel cylinder PRV is realized in the working of ABS/ASR braking regulation, which is important and valuable to the improvement of the ABS/ASR controlling effect.     

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

The anti-lock braking system (ABS) and anti-slip regulation system(ASR) are the very i mportantparts of active safety systems used for modern vehi-cles . This two systems make up of commonintegratesystem ABS/ASR[1 ,2]. At present ,the main controlmethodin ABS/ASRis the logic threshold method.When getting the wheel speed signal ,ECUcomputesand applies control after comparing current signalwith the threshold[3 -5].Because of many reasons ,the wheel speed sig-nals sampled in ABS/ASRalw…     

基于紧急变道策略的汽车主动避障安全车距模型

基于最佳路径规划策略,提出了一种结合车辆纵向速度调节控制和车道变换操作的车辆紧急避障方法,建立了紧急车道变换工况下的安全车距模型,分析了不同制动作用调整车速时间对车辆变道行驶轨迹和安全车距的影响。通过对在同车道前方静态障碍物工况进行仿真,验证了所提出的安全车距模型的有效性。     

ABS智能控制器的设计与仿真

车辆ABS(Antilock Braking System)智能控制是一种优于传统ABS控制的控制技术,能够将车轮滑移率控制在目标滑移率附近,并且自动识别道路附着状况搜索最佳滑移率值,达到利用路面最大附着力的自适应效果.在建立车辆单轮防抱死仿真系统的基础上,设计了一个基于最佳滑移率的积分分离PID自适应控制器,并分别对此进行数字仿真与实物实验,结果表明,该控制器的控制稳定性、鲁棒性和自适应性均取得了良好的效果.     

汽车ABS制动压力抖动仿真与控制

建立复杂的非线性ABS系统与四分之一车数学模型,对不同参数下ABS的性能进行仿真,发现在传统控制方式下,ABS的制动压力抖动与滑移率波动存在一定的矛盾性。提出利用PWM方式控制高速电磁阀的开关,实现制动液流量的连续控制方法,有效地防止了汽车制动主缸压力抖动与滑移率的波动,提高了制动舒适性与安全性。     

Integrated Control System of Vehicle ABS/ASR/ACC Based onMC9S12DP256

The integrated control system of vehicle ABS/ASR/ACC has been developed using the MC9S12DP256 singlechip, which is the new Motorola 16-bit product in HSC12 family.The system including the main control module, the datacollection module and the drive and fault diagnosis module is demonstrated and its data collection function is presented indetail. The system designed by the modularization can supervise the data,drive the valves and pump. The program can bedebugged on line, which is steady and reliable validated by the large numbers of vehicle road tests.     

基于联合控制的汽车驱动防滑系统

为提高前轮驱动车辆在低附着或对开路面上的加速性能,设计了基于节气门与制动干预联合控制的驱动防滑系统.车速较低时选择前后轮速差作为ASR控制量,车速稍高时选择驱动轮滑转率作为ASR控制量.应用扭矩传感器测试了低附着路面的最佳滑转率,设计了基于车轮滑转程度的ASR工况识别方法,开发了针对低附着和对开路面的节气门与制动干预联合控制逻辑,进行了基于捷达GTX轿车的实车试验.试验结果表明,该系统控制逻辑合理,能够对工况做出准确识别,车速较低时将前后轮速差控制在7km/h内,车速稍高时将驱动轮滑转率控制在20%附近,提高了车辆的加速性能.     

New Method for Confirming the Desired Safety Headway Distance and Desired Deceleration in ACC System

A new method of confirming the desired safety headway distance and desired deceleration is put forward according to the detected static or moving target and its simulation results in Matlab are also presented.The validity of the algorithm to calculate the reference speeds of both the ACC vehicle and the targeted car according to the vector quadrangle composed of the relative distance, the relative azimuth angle, the relative speeds of the vehicles has also been demonstrated through numerical example in Matlab. New laws to obtain the desired deceleration by estimating the braking force according to the vehicle analyses force equation are established too.     

Longitudinal Control Strategy f or Vehicle Adaptive Cruise Control Systems

A new longitudinal control strategy for vehicle adaptive cruise control (ACC) systems is presented. The running relationship between the ACC vehicle and the detected target vehicle is described by the relative velocity and the deviation between the actual headway distance and the prescribed safety distance. Based on this, two state space models are built and the linear quadratic optimal control theory is used to yield desired velocity for the ACC-equipped vehicle when with the target vehicle detected. By switching among four control modes, the desired velocity profile is designed to deal with different running situations. A velocity controller, which includes a PID controller for throttle openness and a neural network controller for brake application, is developed to achieve the desired velocity profile. The proposed control strategy is applied to a non-linear vehicle model in a simulation environment and is shown to provide the ACC vehicle comfortable ride and satisfying safety.     

考虑驾驶员行驶特性的双模式自适应 巡航控制设计

为了设计一个能够模拟驾驶员行驶行为的汽车自适应巡航控制(ACC)系统,通过分析驾驶员的日常行驶特性,在模型预测控制的框架基础上提出一个双模式的自适应巡航控制策略：当远离前车时,ACC系统采取快速接近模式,在满足安全舒适的前提下以尽量短的时间减小两车间距;一旦车间距调整至期望值附近时,ACC系统切换到平稳跟车模式,使车辆安全、平稳、舒适地对前车进行跟车;为使2种模式切换时能平滑过渡,利用模糊理论设计了2个模式的切换规则来模拟驾驶员的决策过程.通过仿真试验,证实了该双模式ACC控制策略在满足行驶过程中的安全性以及舒适性的同时,有效地反映了驾驶员的日常行驶习惯,更易于被驾驶员接受,有利于提高ACC系统的使用率.     

基于数据驱动的鲁棒反步自适应巡航控制

为了实现高精度的鲁棒自适应巡航控制（ACC）,提出基于数据驱动的鲁棒反步自适应巡航控制算法. 利用反步技术设计虚拟控制器,将车辆间距控制转化为速度控制,避免速度相关型间距策略带来的间距与速度控制耦合;构建基于数据的耦合滑模面并设计状态观测器,补偿车辆复杂的非线性动力学特性、离散误差及外部干扰,提升控制算法的鲁棒性;利用反馈控制及鲁棒控制技术设计数据驱动的ACC鲁棒控制算法;分别选取固定时间间距、变时间间距策略,利用所提ACC算法及基于比例积分（PI）的ACC算法进行车辆自适应巡航控制对比仿真验证. 对比实验结果表明,所提算法在控制精度、鲁棒性方面具有优越性.     

汽车自适应巡航跟车多目标鲁棒控制算法设计

为满足自适应巡航系统跟车模式下的舒适性需求并且兼顾车辆安全性,基于模型预测控制原理提出一种多目标鲁棒跟车控制算法.建立考虑前车加速度干扰的自适应巡航系统车间纵向运动学模型,该模型可全面反映系统的动态演化规律,提高模型的精度和可靠性;针对自适应巡航系统需求进行目标分析,设计一种考虑舒适性和安全性的多目标模型预测控制算法;针对模型预测控制算法鲁棒性较差的问题,引入修正项反馈,提高控制系统鲁棒性,采用向量约束管理法解决模型预测控制算法硬约束造成的控制系统无优化解问题.仿真结果表明:该算法使跟车时车辆加速度及冲击度保持在舒适性范围,同时车间距始终大于最小安全距离,兼顾了舒适性和安全性要求,实现了自适应巡航控制系统跟车目的.     

Model of desired speed based on vehicle dynamic

The desired speed will help the drivers control their driver behavior that could directly influences the traffic safety.This paper presents a basic definition of a driver’s desired speed,and analyzes the effects of road geometer parameter,driver behavior and vehicle performance on the desired speed.By setting the familiar horizontal curve as the research environment,the generating process of the desired speed was described.Then,combined with the desired trajectory,the effect of driver’s identification of vehicle dynamic on the desired speed was highlighted.Based on the vehicle dynamic theory,a desired speed model that consisted of the desired trajectory,the driver’s experience and vehicle parameter was established and numerically analyzed.