Abstract: | In order to improve the trajectory tracking accuracy and yaw stability of intelligent four-wheel independent drive electric vehicles subject to varied road curvature, a comprehensive control method combining model predictive control with direct yaw moment control is proposed. Firstly the vehicle dynamics model considering lateral and longitudinal coupling is established, and the second-order Runge Kutta discrete method is applied to enhance the accuracy of the discrete model. Based on the simplified two-degree-of freedom dynamics model, the vehicle yaw stability constraints are derived and the nonlinear model predictive controller is designed. Then, due to the fact that the direct yaw moment control can change the vehicle yaw rate and the heading angle, the collaborative control rules are designed, taking into account the prediction state, control command and tracking error of the controller. The simulation results show that the proposed collaborative control solves the contradiction between the stability constraint and control accuracy,compensates the yaw stability constraint if no feasible solution is found, and improves the trajectory tracking
accuracy and yaw stability of intelligent vehicles. |