基于Matlab／Simulink的汽车ABS建模与仿真

该文以单轮车辆为研究对象,建立整车数学模型、轮胎模型、制动器模型、液压系统模型和滑移率的计算模型。对所建立的汽车ABS数学模型进行仿真研究,得出仿真曲线。仿真结果表明,建立的ABS数学模型可靠,能达到较为理想的制动控制效果,验证了汽车ABS具有良好的制动性能和方向操纵性。     

基于增强学习的车辆转弯制动横向轨迹控制

针对传统的车辆转弯制动横向轨迹控制方法存在车辆整体滑移率高,控制后的车辆滑行时间较长、滑行路程较远的问题,提出基于增强学习的车辆转弯制动横向轨迹控制方法.构建车辆SAE坐标系,使用三角函数得到轮胎六分力的联合作用情况,通过拟合计算的形式,获取水平方向漂移数据及其侧向力,构建车辆动力模型,将车辆动力模型转化为线性的二自由度系统,设定车辆滑移率为目标函数,根据计算的函数最优解,使用增强学习算法选取最佳控制策略,从而完成基于增强学习的车辆转弯制动横向轨迹控制方法设计.构建仿真环节,通过与目前使用方法对比可知,上述方法的车辆整体滑移率较低,控制效果较为稳定.     

基于Matlab/Simulink的汽车ABS系统的建模与仿真

以单轮车辆为研究对象,在Matlab/Simulink的环境下建立整车数学模型、双线性轮胎模型、液压制动系统模型和滑移率计算模型,设计PID控制器,对所建立的汽车ABS数学模型进行仿真研究,得出仿真曲线,并将仿真结果与无ABS作用时的制动结果进行对比.结果表明,建立的ABS数学模型可靠,能达到较为理想的制动效果.     

对开路面制动车辆稳定性的控制方法及仿真

汽车在对开路面上紧急制动是汽车制动非常恶劣的一种工况.文中分析了车辆在对开路面上制动的稳定性问题并提出了相应的解决办法,根据简化车辆模型建立了相应状态空间方程,采用最优控制方法解决车辆稳定性问题.结合制动车辆的ABS(防抱制动系统),调整相应车轮的目标滑移率,通过对车辆的横摆力矩控制和相应的车轮滑移率和附着系数的调节使车辆保持制动稳定性,从而可以在不增加硬件成本的条件下完成车辆的稳定性控制.对车辆在对开路面的制动工况进行了仿真,结果表明,所提出的方法能有效改善对开路面上车辆的制动稳定性.     

防抱制动系统滑模状态观测和控制系统仿真

该文在考虑不平路面随机激励作用下车辆垂向振动的基础上 ,首先建立了四分之一车辆制动模型 ,而后充分运用滑移模式变结构的分析和设计方法 ,提出了车轮最佳滑移率的滑模实时在线辨识滑模优化算法 ,在对系统可观测性论证的基础上 ,设计了非线性滑模状态观测器 ,给出了单通道防抱制动系统基于滑移率的滑模控制算法 ,通过计算机仿真 ,验证了该控制算法的可行性和有效性 ,为设计具有高鲁棒性的防抱制动系统做了一定的理论探索和仿真工作     

基于逻辑门限值的客车ABS硬件在环测试研究

针对ABS控制器开发过程中纯数值仿真过于理想化,实车试验成本高、周期长等缺点,设计并搭建了客车ABS硬件在环仿真测试系统;系统由xPC目标实时仿真环境、气制动系统及整车动力学模型组成;气制动系统按照真实客车制动系统并配合力传感器搭建;整车动力学模型由轮胎模型、七自由度车辆模型、制动器模型等组成,并利用Simulink建模;在ABS控制策略中引入逻辑门限值控制,在客车ABS硬件在环仿真测试系统上测试了客车在高附着系数、低附着系数及对接路面上的制动情况;试验表明:逻辑门限值控制能很好地将车轮滑移率控制在最佳滑移率附近,具有较好的控制精度及鲁棒性。     

利用ADAMS与MATLAB对ABS滑模变结构控制的仿真

为了减少车辆控制系统的开发时间和费用,联合仿真的方法受到越来越多的重视。将多体系统动力学与智能控制理论相结合,对汽车制动防抱死控制系统进行了研究。它结合了不同软件的优点,可以在设计阶段验证控制算法对车辆性能的影响。利用ADAMS/CAR建立了汽车整车多体动力学模型,利用MATLAB/Simulink建立了基于滑移率的滑模变结构防抱死控制系统,利用ADAMS/Controls接口进行模型的集成、系统仿真。结果证明联合仿真方法对ABS系统设计切实可行,该控制算法具有较强的实用性。     

基于路面识别实时控制车轮滑移率的ABS系统

汽车防抱死制动系统(ABS)是一种很重要的汽车主动安全技术。并针对路面具体情况,对车辆防抱制动系统的滑移率实时控制进行研究。该文在MATLAB/Simulink仿真环境下,建立车辆动力学模型,实现了对路面状况识别,同时对基于滑移率控制的防抱制动系统的计算机仿真。仿真结果表明,该系统能真实地反映汽车ABS系统的实际工作过程,达到了满意的控制效果。     

基于TruckSim的三轴汽车自寻最优ABS控制设计

为提高三轴汽车的制动安全性能,在TruckSim中建立了三轴整车模型,针对以往研究中自寻最优理论不能应用到整车模型的问题,设计了简单可行的控制逻辑,将该理论应用到三轴整车模型。在TruckSim中建立了对开路面、对接路面、低附着路面、高附着路面四种工况,采用TruckSim与Simulink联合仿真,加入传统逻辑门限ABS作为对比,验证控制器的可行性。仿真结果表明,在四种工况下,自寻最优ABS的制动性能都要优于传统ABS,其中,在低附着路面工况下,自寻最优ABS的优越性最突出,制动距离减少24.5m,制动时间减少2.04s。说明自寻最优ABS可以自动搜索轮胎的最佳滑移率,提高三轴汽车的制动安全性能。     

联合制动系统性能仿真

该文分别介绍了联合制动系统的两部分———湿式多片盘式制动器和液力减速器的概念及工作原理 ;考虑车辆的旋转质量换算系数、传动效率、滑移率、制动力系数等影响因素 ,建立湿式多片盘式制动器和液力减速器联合制动的数学模型 ;利用MATLAB的SIMULINK仿真模块 ,研究联合制动的车辆制动性能 ,并与只用湿式多片盘式制动器的车辆制动性能对比 ,得出相关的结论。     

Adaptive neuro-fuzzy wheel slip control

Due to complex and nonlinear dynamics of a braking process and complexity in the tire–road interaction, the control of automotive braking systems performance simultaneously with the wheel slip represents a challenging problem. The non-optimal wheel slip level during braking, causing inability to achieve the desired tire–road friction force strongly influences the braking distance. In addition, steerability and maneuverability of the vehicle could be disturbed. In this paper, an active neuro-fuzzy approach has been developed for improving the wheel slip control in the longitudinal direction of the commercial vehicle. The dynamic neural network has been used for prediction and an adaptive control of the brake actuation pressure, during each braking cycle, according to the identified maximum adhesion coefficient between the wheel and road surface. The brake actuation pressure was dynamically adjusted on the level that provides the optimal level of the longitudinal wheel slip vs. the brake pressure selected by driver, the current vehicle speed, the brake interface temperature, vehicle load conditions, and the current value of longitudinal wheel slip. Thus the dynamic neural network model operates (learn, generalize and predict) on-line during each braking cycle, fuzzy logic has been integrated with the neural model as a support to the neural controller control actions in the case when prediction error of the dynamic neural model reached the predefined value. The hybrid control approach presented here provided intelligent dynamic model – based control of the brake actuation pressure in order to keep the longitudinal wheel slip on the optimum level during a braking cycle.     

A novel method for non-linear control of wheel slip in anti-lock braking systems

Anti-lock braking system (ABS) provides active safety for vehicles during braking by regulation of the wheel slip at its optimum value. Due to the non-linear characteristics and model uncertainties in vehicle dynamics, a non-linear controller with increased robustness should be designed for ABS. In this paper, to achieve this aim, an optimization-based braking torque control law is developed for ABS using the prediction of the wheel slip response from a continuous non-linear vehicle dynamics model. To increase the robustness of the controller, the integral feedback technique is appended to the design method. The derived control law and its special cases are evaluated and discussed. At the end, the performance of the proposed controller is compared with that of a sliding mode controller, reported in the literature, through simulations of braking on dry and slippery roads. The simulation results indicate that, the wheel slip tracking error is remarkably decreased by the proposed controller. Moreover, the achieved control input is entirely smooth and suitable for implementation.     

基于车轮加速度和滑移率的EBD控制策略

ABS控制并不适用于所有制动工况,由此进一步发展衍生出了电子制动力分配系统(Electric Brake force Distribution,EBD)。针对EBD的功能将EBD的工况分为轻制动、强制动和ABS故障,并分别设计控制策略,实现了一种以车轮加速度和滑移率为门限值的逻辑控制策略。控制策略通过增压、减压和保压调整轮缸制动压力,优先保证制动过程的稳定性,并且在轻制动时注重舒适性,强制动时减缓后轮压力上升速率,ABS故障时EBD代替ABS对后轮进行制动控制。基于车辆动力学仿真软件ve-DYNA的仿真测试和基于ve-DYNA与dSPACE构建的车辆底盘开发平台的硬件在回路测试表明,此EBD控制策略既能防止后轮先于前轮抱死,又能保证制动舒适性和较高的制动效率。     

Robust cascaded automatic cruise control of electric vehicles

This article focuses on automatic cruise control for electrically driven vehicles. The objective is to track a given vehicle‐velocity profile. For this type of application, the so‐called wheel slip plays a key role, as it is a measure for the force transmitted from the wheel to the road. Conventional wheel‐ slip controllers are usually activated if the absolute value of the slip exceeds pre‐assumed thresholds. Furthermore, it is distinguished between a braking and acceleration maneuver using separately designed and implemented controllers. In contrast, the proposed concept requires neither an activation strategy for the slip controller nor a distinction between braking and acceleration. The cascaded control structure is based upon adaptive‐gains super twisting sliding‐mode algorithm, and the friction force estimator is realized as a second‐order sliding‐mode observer with constant gains. The effectiveness and robustness of the proposed concept are demonstrated in numerical simulations using a complex multibody vehicle model. Copyright © 2015 John Wiley & Sons, Ltd.     

基于LabVIEW的汽车ABS性能检测系统仿真研究

本文以汽车制动性能评价指标为检测目标,提出了利用USB总线进行数据采集、基于LabVIEW虚拟平台的设计方案,并对制动性能检测系统进行了仿真研究。该系统能实现制动距离、制动时间、滑移率等性能参数的检测及其数据处理、曲线显示和数据存储等功能,为开发和研制汽车ABS性能检测系统提供了理论基础。     

电动汽车电-液并联ABS制动系统能量回收研究

为了提高续驶里程,针对某款越野车改装的电动汽车制动系统,提出一种基于ABS的电-液并联制动系统。此系统采用固定比例的前后轴制动力分配方式,结合恒定充电电流与最大回馈功率复合的再生制动控制方式,以基于滑移率的PID控制ABS系统来调节电、液制动力比例,在确保制动安全可靠的同时实现制动能量回收。根据上述理论建立数学模型,并利用AMESim和Simulink进行联合仿真,在3种典型工况下分析制动性能和能量回收效率。结果表明：基于ABS的电-液并联制动系统综合制动性能良好,且3种工况下的一次制动最小能量回收效率分别达到28%、28%和11%。     

电动汽车低速电气制动防抱死功能的研究

研究电动汽车制动防抱死功能优化问题,电动汽车在冰雪路面上进行纯再生制动时,驱动轮极有可能抱死,从而造成车辆操纵稳定性下降。为解决上述问题,根据驱动电机在基速以下的调速特性,提出了调压调速型电气ABS模型。以单轮电动汽车模型为研究对象,设计了以车轮滑移率为控制目标的滑动模式防滑控制器。在Matlab/Simulink环境下建立了电气ABS仿真模型,仿真结果表明所建模型具有良好的稳定性;同时表明制动过程由初期的反接制动、为主体的中期再生制动及后期的反接制动构成;且制动精度明显高于传统ABS。研究结果对电动汽车再生制动系统的设计具有一定的参考价值。     

Evaluation of antilock braking system with an integrated model of full vehicle system dynamics

Antilock braking system (ABS), traction control system, etc. are used in modern automobiles for enhanced safety and reliability. Autonomous ABS system can take over the traction control of the vehicle either completely or partially. An antilock braking system using an on–off control strategy to maintain the wheel slip within a predefined range is studied here. The controller design needs integration with the vehicle dynamics model. A single wheel or a bicycle vehicle model considers only constant normal loading on the wheels. On the other hand, a four wheel vehicle model that accounts for dynamic normal loading on the wheels and generates correct lateral forces is suitable for reliable brake system design. This paper describes an integrated vehicle braking system dynamics and control modeling procedure for a four wheel vehicle. The vehicle system comprises several energy domains. The interdisciplinary modeling technique called bond graph is used to integrate models in different energy domains and control systems. The bond graph model of the integrated vehicle dynamic system is developed in a modular and hierarchical modeling environment and is simulated to evaluate the performance of the ABS system under various operating conditions.