采用分数阶趋近律的汽车ABS积分滑模控制研究

Study on Integral Sliding Mode Control of Vehicle ABS Based on Fractional Approach Law

为研究和评价ABS性能,以单轮车辆模型为基础,建立了单轮车辆动力学模型、轮胎模型及滑移率与附着系数的数学模型。在此基础上,提出了一种采用分数指数趋近律的汽车防抱死制动系统滑模变结构控制策略。这里主要采用含积分的滑模函数来设计切换函数,并结合分数阶指数微分方程、F-函数定义与性质,设计了分数阶指数趋近律。然后以实现高精度的滑模控制为目标,推导得到控制器总的等效控制输出。同时,在Matlab/Simulink中进行系统建模和仿真实验。结果表明:相比整数阶的汽车防抱死滑模控制系统滑移率能够更快、更准的跟踪达到期望值,制动时间和制动距离明显降低。

In order to study and evaluate ABS performance,a single wheel vehicle dynamics model,tire model,slip ratio and adhesion coefficient mathematical model are established based on single wheel vehicle model.On this basis,a sliding mode variable structure control strategy of vehicle anti-lock braking system by using fractional exponential approach law is proposed.A sliding function with integral is used to design the switching function,and combined with the definition and properties of fractional exponential differential equation and F-function,the fractional exponential reaching law is designed.Then,the total equivalent control output of the controller is derived for achieving the goal of high precision sliding mode control.Meanwhile,the system modeling and simulation experiments are carried out in Matlab/Simulink.The simulation results show that the sliding rate tracking error of the fractional order system compared with the sliding mode control with integer order is faster and more accurate to the expected value,and the braking distance is obviously reduced.