Vehicle Active Steering Control Research Based on Two-DOF Robust Internal Model Control

Because of vehicle＇s external disturbances and model uncertainties,robust control algorithms have obtained popularity in vehicle stability control.The robust control usually gives up performance in order to guarantee the robustness of the control algorithm,therefore an improved robust internal model control（IMC） algorithm blending model tracking and internal model control is put forward for active steering system in order to reach high performance of yaw rate tracking with certain robustness.The proposed algorithm inherits the good model tracking ability of the IMC control and guarantees robustness to model uncertainties.In order to separate the design process of model tracking from the robustness design process,the improved 2 degree of freedom（DOF） robust internal model controller structure is given from the standard Youla parameterization.Simulations of double lane change maneuver and those of crosswind disturbances are conducted for evaluating the robust control algorithm,on the basis of a nonlinear vehicle simulation model with a magic tyre model.Results show that the established 2-DOF robust IMC method has better model tracking ability and a guaranteed level of robustness and robust performance,which can enhance the vehicle stability and handling,regardless of variations of the vehicle model parameters and the external crosswind interferences.Contradiction between performance and robustness of active steering control algorithm is solved and higher control performance with certain robustness to model uncertainties is obtained.

Steering and braking game control architecture based minimax robust stability control for emergency avoidance of autonomous vehicles

The existing electronic stability control(ESC)system does not consider the steering intention of an autonomous driving system(ADS)during autonomous driving emergency avoidance.The distributed control scheme between ESC and ADS does not involve any information interaction,and the balance between path tracking and lateral stability is not optimal.A Nash game control scheme of steering and braking system is proposed to ensure that both path tracking and stability are simultaneously in the loop and solve the conflict by simulating the interaction between the two agents considering the impact on the interaction between a path following and lateral stability.Each agent considers its interests and the opponent’s interest,resulting in a global optimal control solution of steering control and ESC.Then,using minimax optimization theory,a lateral stability strategy is proposed to make the game control architecture under emergency avoidance more robust to uncertain lateral disturbances.Finally,simulation and hardware in the loop experiments show that the proposed scheme can consider both vehicle’s path following performance and lateral stability in the event of an emergency.