基于 Tube MPC 的多轴重型车辆全轮转向路径跟踪策略

An all-wheel steering path tracking strategy based on model predictive control with robust invariant set is proposed for a five-axle heavy-duty vehicle in this paper. Firstly，an all-wheel steering path tracking strategy based on first-axle and fifth-axle steering angle control is put forward to make the multi-axle vehicle more flexible in control，with the lateral force response synchronized and fully utilized. Then with considerations of the uncertainty of tire parameters and the bounded disturbance caused by side-wind in the control model，the Tube MPC is used to solve the path tracking problem. Meanwhile，a simplified minimum robust positively invariant set（mRPI）based on support function calculation is adopted to replace the general Minkowski sum-based mRPI operation，effectively saving the offline computation time of mRPI，reducing the number of vertices in the invariant set，and ensuring the online implementation of Tube MPC. Finally，a hardware-in-the-loop simulation is carried out with a result verifying that the Tube MPC-based all-wheel steering strategy proposed has higher path tracking accuracy and vehicle stability and stronger robustness when facing unknown disturbance，compared with ordinary all-wheel steering strategy.