四轮独立转向无人车辆斜向行驶轨迹跟踪控制方法

Aiming at the problem of high cost of steering system of four-wheel independent steering electric vehicle (4WIS-EV) and less functional development, a vehicle oblique driving control method was proposed to optimize the driving stability of 4WIS-EV during lane changing. Firstly, based on the 4WIS-EV lateral and longitudinal two-degree-of-freedom vehicle model, a lateral and longitudinal coupled trajectory tracking control method was proposed. According to linear-time-variant (LTV) model and model predictive control (MPC) algorithm, a closed-loop control of lateral deviation, heading angle deviation and longitudinal speed deviation was carried out. And then, a vehicle stability controller was designed, including yaw moment controller and torque distribution controller to improve trajectory tracking accuracy and driving stability simultaneously. Finally, a Simulink/Carsim/Prescan co-simulation platform was built to carry out the lane-changing simulation of the 4WIS-EV in double-line shifting condition. The simulation results show the feasibility of the oblique lane change and the effectiveness of the lateral and longitudinal coupled trajectory tracking control method.