关键词: 汽车工程, 分布式驱动电动汽车, 路径跟踪, 稳定性控制

Abstract:  A path tracking control strategy with integrated vehicle stability was proposed to improve the path tracking precision and vehicle stability of distributed drive electric vehicles under dangerous driving conditions such as high speed and low adhesion conditions. The hierarchical structure path tracking control strategy with vehicle stability, including the path tracking control layer, the stability controller decision layer and the drive wheel torque distribution layer. To solve the problem of the lower accuracy of LQR path tracking controller under high-speed and large curvature conditions, a closed loop PID correction driver model was used to compensate the front wheel angle of the vehicles. In addition, the stability controller was designed to track the ideal reference model of the vehicles. The controller developed the model predictive control algorithm to generate additional yaw moment. Meanwhile, the controller realized the optimal distribution of the wheel drive torques with the objective of minimizing tire load rate. Based on the independently designed distributed drive electric test vehicle, the double lane change tests were carried out on high-speed high adhesion road surfaces and high-speed low adhesion road surfaces respectively. The results show that, when driving on dry concrete pavement at 90 km/h speed, the lateral root mean square errors of the path tracking precision with integrated dynamics stability reduce by 29.7%, compared to the LQR path tracking controller using only closed-loop PID correction for path tracking. When driving on wet asphalt pavement at 70 km/h speed, the lateral root mean square errors reduce by 10.3%. Therefore, the proposed path tracking control strategy with integrated vehicle stability of distributed drive electric vehicles may improve path tracking accuracy, ensuring yaw stability under extreme conditions effectively. 

Key words: automotive engineering, distributed drive electric vehicle, path tracking, stability control