考虑横向稳定性的智能车辆路径跟踪控制

Path Following Control of Intelligent Vehicles Considering Lateral Stability

对于智能车辆的路径跟踪,传统位置偏差控制方法往往忽略了车辆的动态稳定性.针对这一问题提出一种考虑横向稳定性的智能车辆路径跟踪控制方法.首先建立二自由度车辆动力学模型和路径跟踪误差模型,综合考虑车辆位置偏差和车辆动力学状态,利用基于反馈优势的反推法(FDB)生成期望横摆角速度;然后基于线性二次型跟踪器(LQT)设计了主动前轮转向(AFS)和直接横摆力矩控制(DYC)的集成控制策略,得到了理想的控制输入(前轮转角和外部横摆力矩),进而实现精确跟踪期望横摆角速度和质心侧偏角;最后在Simulink仿真环境中对提出的控制方法进行验证.结果表明:提出的控制方法在路径跟踪的同时具有很好的横向稳定性能;相比于不考虑横向稳定性的控制方法,提出的方法在路径跟踪过程中跟踪精度更高,车辆的质心侧偏角更小,横摆角速度也能更好的跟踪期望值.

For the problem of path following in autonomous vehicles,the traditional position deviation control me-thod used to neglect the dynamic stability of vehicle.To solve this problem,a control method taking into account the lateral stability of path-following is proposed.Firstly,2-DOF vehicle dynamics model and path-following error model are established.Secondly,taking into consideration the position of vehicle and the state of vehicle dynamics,the desired yaw rate is generated through the use of the back-stepping feedback dominance back-stepping(FDB).After that,an integrated control strategy of active front steering(AFS)and direct yaw moment control(DYC)based on LQT(linear quadratic tracker)are designed.Next,the ideal control inputs(front wheel angle and yaw moment)are obtained,and the desired yaw rate and sideslip angle is thus tracked accurately.Finally the proposed method is verified in the Simulink environment.The simulation results show that the proposed control method has good lateral stability in path tracking.Compared with the method without considering the lateral stability,the me-thod proposed has higher tracking accuracy in the process of path tracking,the sideslip angle of the vehicle is smaller,and the yaw rate can better track the desired value.