现代控制理论在汽车防抱制动系统中的应用

汽车防抑制动系统常采用以下三种控制方式：逻辑门限值控制、最优控制及滑动变结构控制。最优控制是基于状态空间法的现代控制理论方法，它可以根据车辆－路面系统的数学模型，用状态空间的概念，在时间域内研究汽车防抱制动系统。它是一种基于模型的分析型的控制系统，它根据防抱制动系统的各项控制要求，按最优化原理求得控制系统的最优控制指标。具体来讲，它将车轮的角速度和角加速度作为状态变量对系统进行优化控制，能达到很好     

基于最优变结构的防抱控制系统的研究

车轮制动的防抱系统是一类非线性系统，轮胎与路面间附着系数本身是非线性的且变化很大；结合滑模变结构和最优方法对防抱制动系统的控制进行了研究，很好地解决了控制的精确性等问题；在不同的滑移率误差区域采用不同的控制系统，人而得到很好的控制效果。     

车辆动力学控制的模拟

本文用模拟方法研究了车辆动力学控制系统。采用闭环的横摆角速度及车辆侧偏角控制，用它们之间的相平面分析确定控制策略。这一控制集成了基于滑移率控制的ＡＢＳ系统，实施简单，鲁棒性强，模拟结果显示该系统能有效地改善车辆的动力学性能。     

汽车ABS模糊控制方法的研究与仿真

将模糊控制理论用于汽车防抱死制动系统，确定防抱制动系统的参数。提出了车速估算的模糊逻辑方法。针对简化的汽车模型，用MATLAB模糊控制工具箱进行了模糊控制器的设计，并在SIMULINK仿真环境下进行了动态仿真，结果表明：基于模糊控制的防抱控制的防抱控制系统鲁棒性强，控制效果好，可实施性好。     

一种基于模型的最佳滑移率计算方法

基于滑移率控制的防抱制动系统(ABS)实现的难点在于确定各种路况下的最佳滑移率。本文基于μ λ曲线的参数模型,应用Kalman滤波理论实时计算了不同路面下的最佳滑移率。根据Kalman滤波新息序列特性,设计了路面跃变监视器,解决了Kalman滤波算法在检测跃变路面时响应滞后的问题。最后通过计算机仿真,验证了基于模型的最佳滑移率估计算法在车辆防抱制动系统中的可行性和有效性。     

在防抱制动控制中比较量的选择

汽车防抱制动系统广泛采用的是逻辑门限值控制，对于非线性系统是一种有效的控制方法。本论了几种不同的控制逻辑，通过对制动过程的动态模拟，比较了其防抱性能优劣。     

适应不同路面条件下的ABS制动仿真研究

汽车防抱制动系统ABS是改善汽车主动安全性的重要装置,本文利用Mat-lab/Simulink仿真软件,建立了车辆制动防抱系统仿真模型。通过仿真分析得到了车辆在不同路面制动时的滑动率,提出在不同路面制动时滑动率控制的最佳值,使车辆制动时的滑动率达到这一最佳值,从而可以实现车辆在不同路面条件制动时保持稳定的制动力,缩短制动距离。     

汽车缩略词辨析(二十八)

车辆动态控制系统(VDC)(日产) VDC(Vehicle Dynamics Control)是日产西马牌高级轿车采用的提高行驶稳定性的系统,日产汽车公司以前采用的是驱动力控制系统(TCS)/防抱制动系统(ABS).在打滑的路面上起步或加速时驱动轮易发生空转,汽车就不能够进行充分加速,并产生翘尾现象,从而使车辆失去稳定性.     

基于模糊控制理论的汽车ABS控制方法研究

介绍了模糊控制理论在汽车防抱死制动系统中的应用，提出了车速估算的模糊逻辑方法，并在SIMULINK仿真环境下进行了动态仿真。结果表明，基于模糊控制的防抱控制系统鲁棒性强，控制效果好，可实施性好。     

防抱制动系统基于模型的最佳滑移率计算方法

提出了一种基于μ-λ曲线的近似数学模型来实现最佳滑移率的递推最小二乘算法(RLS)。应用累积求和统计控制法(CUSUM)，解决了RLS算法在检测跃变路面时响应滞后的问题。通过计算机仿真，验证了算法在车辆防抱制动系统中的可行性和有效性。     

基于滑移率和减速度的ABS模糊控制仿真研究

在ABS逻辑门限值控制方法的基础上,通过分析道路试验数据,利用M atlab的模糊工具箱建立了模糊控制系统,采用7自由度整车模型在S imu link中进行仿真计算。仿真结果表明,基于滑移率和减速度的ABS模糊控制比逻辑门限值方法具有更好的自适应性,并可减少道路试验的工作量。     

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。     

汽车防抱死制动系统的自抗扰控制研究

汽车防抱死制动系统（Anti-lock Braking System,ABS）的作用是确保汽车制动时行驶方向的稳定性、可靠性,但是目前仍存在非线性、时变性以及参数不确定性等问题。为保证汽车制动行驶过程中的操纵稳定性和安全性,进一步实现各工况下防抱死制动系统的优化控制,以影响整车稳定的变量滑移率为研究对象,分析所设计策略的控制效果。搭建汽车动力学模型、制动系统模型、轮胎模型和滑移率模型等主要模型,设计基于滑移率的ABS二阶非线性自抗扰控制器。运用MATLAB/Simulink软件对基于自抗扰控制（Active Disturbance Rejection Control,ADRC）的ABS制动过程和基于模糊PID控制的ABS制动过程进行仿真,对比研究最佳滑移率、载荷、水泥-冰对接路面、扰动等对制动过程中的轮速、车速以及滑移率等动态性征反映的稳定性和抗扰能力的影响,同时研究其对最终制动距离和最终制动时间反映的制动性能的影响。最后,将自抗扰控制器和模糊PID控制器装配于试验车辆的ABS,进行水泥路面和冰-水泥对接路面制动过程的实车试验。研究结果表明：基于二阶非线性自抗扰控制算法的ABS制动的最终制动距离和最终制动时间更短、制动效果更优,制动过程中的轮速、车速和滑移率在响应速度、稳定性和抗扰能力等方面均更佳;试验结果与仿真结果吻合,证明了仿真模型及其仿真结果的可行性和正确性。     

基于路面附着系数曲线的最佳滑移率计算方法

滑模控制应用于ABS系统中可较好地跟踪任意指定滑移率,但最佳滑移率却随着路面情况而变化。从单轮制动时动力学模型着手,提出了基于附着系数曲线求取最佳滑移率的防抱死制动方法,间接实现了滑模控制器对最佳滑移率的跟踪控制,并通过计算机仿真,验证了此方法的可行性和有效性。     

Coordinated vehicle traction control based on engine torque and brake pressure under complicated road conditions

Vehicle traction control system has been developed to enhance the traction capability and the direction stability of the driving wheels through the tyre slip ratio regulation. Under normal situations, if the tyre slip ratio exceeds a certain threshold, the slip ratio of the driving wheel is regulated by the coupled interaction of the engine torque and the active brake pressure. In order to obtain the best driving performance on a road under complicated friction conditions, the driving torque and the active brake pressure, need to be decoupled and adjusted to avoid penalisation of each other. In this paper, a coordinated cascade control method with two sliding-mode variable structure controllers is presented. In this control method, the driving wheel slip ratio is regulated by adjusting the engine torque and the wheel brake pressure. Through the sliding-mode controller, the engine torque is tuned to achieve the maximum driving acceleration and then the active brake pressure is applied to the slipped wheel for further modification of the wheel slip ratio. The advantage of this control method is that through proper regulation, the conflict between the two control inputs could be avoided. Finally, the simulation results validate the effectiveness of the proposed method.     

Wheel slip control with torque blending using linear and nonlinear model predictive control

Modern hybrid electric vehicles employ electric braking to recuperate energy during deceleration. However, currently anti-lock braking system (ABS) functionality is delivered solely by friction brakes. Hence regenerative braking is typically deactivated at a low deceleration threshold in case high slip develops at the wheels and ABS activation is required. If blending of friction and electric braking can be achieved during ABS events, there would be no need to impose conservative thresholds for deactivation of regenerative braking and the recuperation capacity of the vehicle would increase significantly. In addition, electric actuators are typically significantly faster responding and would deliver better control of wheel slip than friction brakes. In this work we present a control strategy for ABS on a fully electric vehicle with each wheel independently driven by an electric machine and friction brake independently applied at each wheel. In particular we develop linear and nonlinear model predictive control strategies for optimal performance and enforcement of critical control and state constraints. The capability for real-time implementation of these controllers is assessed and their performance is validated in high fidelity simulation.     

Fuzzy Logic Traction Controllers and their Effect on Longitudinal Vehicle Platoon Systems

This paper presents two fuzzy logic traction controllers and investigates their effect on longitudinal platoon systems. A fuzzy logic approach is appealing for traction control because of the nonlinearity and time-varying uncertainty involved in traction control systems

The fuzzy logic traction controllers we present regulate brake torque to control wheel slip, which is the normalized difference between wheel and vehicle speed. One fuzzy controller estimates the peak slip corresponding to the maximum tire-road adhesion coefficient and regulates wheel slip at the peak slip. The controller is attractive because of its ability to maximize acceleration and deceleration regardless of road condition. However, we find through simulations the controller's performance degrades in the presence of time-varying uncertainties. The other fuzzy logic controller regulates wheel slip at any desired value. Through simulations we find the controller robust against changing road conditions and uncertainties. The target slip is predetermined and not necessarily the peak slip for all road conditions. If the target slip is set low, stable acceleration and deceleration is guaranteed, regardless of road condition

We also study the effect of traction control on longitudinal vehicle platoon systems using simulations. The simulations include acceleration and deceleration maneuvers on an icy road. The results indicate traction control may substantially improve longitudinal platoon performance, especially when icy road conditions exist.     

A vehicle ABS adaptive sliding-mode control algorithm based on the vehicle velocity estimation and tyre/road friction coefficient estimations

A sliding-mode observer is designed to estimate the vehicle velocity with the measured vehicle acceleration, the wheel speeds and the braking torques. Based on the Burckhardt tyre model, the extended Kalman filter is designed to estimate the parameters of the Burckhardt model with the estimated vehicle velocity, the measured wheel speeds and the vehicle acceleration. According to the estimated parameters of the Burckhardt tyre model, the tyre/road friction coefficients and the optimal slip ratios are calculated. A vehicle adaptive sliding-mode control (SMC) algorithm is presented with the estimated vehicle velocity, the tyre/road friction coefficients and the optimal slip ratios. And the adjustment method of the sliding-mode gain factors is discussed. Based on the adaptive SMC algorithm, a vehicle's antilock braking system (ABS) control system model is built with the Simulink Toolbox. Under the single-road condition as well as the different road conditions, the performance of the vehicle ABS system is simulated with the vehicle velocity observer, the tyre/road friction coefficient estimator and the adaptive SMC algorithm. The results indicate that the estimated errors of the vehicle velocity and the tyre/road friction coefficients are acceptable and the vehicle ABS adaptive SMC algorithm is effective. So the proposed adaptive SMC algorithm can be used to control the vehicle ABS without the information of the vehicle velocity and the road conditions.     

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.     

A Sliding Mode Controller for Wheel Slip Ratio Control System

A sliding mode controller has been developed for a wheel slip ratio control system for commercial vehicles with sluggish braking actuators to replace conventional if-then rule-like ABS control laws. New techniques overcome the tendency of sliding mode controllers to chatter. Computer simulation (hardware-in-the-loop simulation) and actual vehicle tests verified the effectiveness of this method to suppress chattering and keep the wheel slip ratio in a desirable range during braking on low-friction road surfaces.