四轮轮毂电机独立驱动电动汽车轨迹跟踪与横摆稳定性协调控制研究

In order to improve trajectory tracking precision and dynamics stability of intelligent vehicles under extreme conditions such as high speed and low adhesion conditions, this paper proposes a coordinated control strategy of trajectory tracking and direct yaw-moment based on the layered control structure for autonomous four-wheel-independent-driving electric vehicles, which consists of an upper and a lower controller. Firstly, in the upper controller, a model predictive controller is developed based on the three-degree-of-freedom (3-DOF) vehicle dynamics model considering multiple nonlinear constraints while optimizing the prediction time domain and control time domain through theoretical analysis. The steering angle of the front wheels and the additional yaw-moment are derived via optimization derivation. Then, in the lower controller, the optimal distribution of wheel longitudinal force is realized with the objective of minimizing the load rate of tires. Considering the real-time requirement of the control strategy, the effective set algorithm is adopted for the optimal torque distribution. Finally, the effectiveness of the proposed control scheme of coordinated controller of trajectory tracking and yaw stability is verified under different vehicle speeds and road adhesion coefficients in the CarSim-Simulink joint simulation.