汽车主动前轮转向的自抗扰控制器设计

Design of Active Disturbance Rejection Controller for Active Front Steering Vehicle

传统转向系统对驾驶员误操作不能予以纠正,在驾驶过程中驾驶员需不断修正方向以消除外界或内部对车辆的扰动;主动前轮转向系统产生独立于驾驶员的附加前轮转角,改变车辆的横向受力状态克服传统转向系统不足。提出采用自抗扰技术的汽车主动前轮转向系统,根据系统的输入和输出动态跟踪理想参考横摆角速度,使车辆在横摆角速度安全裕度内运行。在MATLAB中实现了自抗扰控制器算法,控制CarSim车辆模型进行直线行驶抗扰试验和双移线试验,研究了自抗扰控制转向系统的抗扰动性能、路径跟踪性能以及对参数变化的鲁棒性,并与PID控制试验结果进行对比。试验结果表明,自抗扰控制的主动前轮转向系统改善了车辆操纵稳定性,具有抗干扰能力强、路径跟踪性能良好和鲁棒性强等优点,且各项性能优于PID控制器。

For the conventional vehicle steering system, the driver＇s mistake operations can not be corrected, antithe driver needs to constantly amend direction to eliminate internal or external disturbances on vehicle duringdriving. An additional front wheel angle being independent to the driver＇s action is provided by active front steering（AFS） , so lateral force of the vehicle is changed to overcome the shortages of traditional steering system. In thispaper, the desired yaw rate is dynamically tracked by AFS using active disturbance rejection （ADR） techniqueaccording to the input and output of the system, and vehicle runs in yaw rate security margin. Active disturbancerejection controller （ADRC） algorithm was realized in MATLAB, and CarSim vehicle model was controlled byADRC to carry out straight driving anti-disturbance test and double lane change test. Anti-disturbance performance,path tracking performance and robustness to parameter variations of active disturbance rejection control steeringsystem were investigated, and compared with PID control test results. The test results show that controllability andstability of vehicle with ADRC was improved by the AFS that has strong disturbance rejection, good trackingperformance and robustness, and various performances are better than PID controller.