关键词: 极限工况, 模型预测控制, 模糊控制, 四轮转向, 轨迹跟踪控制

Abstract: In order to improve the trajectory tracking accuracy of driverless four-wheel steering vehicles under extreme conditions of different road adhesion coefficients, this paper proposes a trajectory tracking control strategy. A vehicle three-degree-of-freedom dynamic model is established as the controller prediction model and the front wheel steering controller is designed through predictive model control theory. Considering the effect of the center-of-mass slip angle on vehicle stability, a rear wheel steering controller is designed based on the fuzzy control theory. A co-simulation model is established in Matlab/Simulink and CarSim software platforms. The high-speed turning condition on high-adhesion roads and the medium-speed turning condition on low-adhesion roads are selected for comparative experiments. The results show that, considering the center-of-mass slip angle, the rear wheel steering controller ensures the high-speed steering stability of the driverless four-wheel steering vehicle. At the same time, compared with the rear wheel angle controller without considering the center-of-mass slip angle, the trajectory tracking accuracy improves about 25%