汽车TCS液压控制单元特性测试与控制应用

Test and application of hydraulic control unit in automotive traction control system

为实现汽车牵引力控制系统(TCS)中的主动液压制动控制精细调节,搭建了基于dSPACE的液压控制单元(HCU)性能测试系统,对HCU电磁阀特征参数进行了试验辨识,确定了采用脉宽调制控制(PWM)进行制动压力控制时目标压力梯度和目标占空比的映射关系。将测试分析结果应用于基于滑模控制的TCS算法,确定了基于目标压力梯度的PWM车轮制动控制逻辑,并在Matlab/Simulink和AMESim联合仿真环境下进行了仿真验证。结果表明:所设计的主动制动控制算法能以较高精度有效调节车轮滑转率,从而改善车辆行驶性能。

In order to modify the hydraulic brake pressure accurately for Traction Control System （TCS）, a Hydraulic Control Unit （HCU） test system based on dSPACE was developed. Using this system, the characteristic parameters of HCU valves were identified, and the relationship between the desired pressure gradient and target duty cycle in Pulse Width Modulation （PWM） brake control was obtained. In addition, the experiment and analysis results were used in the sliding-mode-based traction control algorithm and the wheel brake control logic based on target pressure gradient was proposed. The algorithm was verified using Matlab/Smulink and AMESim co-simulation. The results show that the proposed active brake control algorithm can provide high accurate regulation of wheel slip ratio, thus, the vehicle driving performance can be improved effectively.