Coordination Control for Path Tracking and Stability of 4WS-4WID Automated Vehicles: A Game Theory-Based Approach

Aiming at the multi-objective control problem of tracking accuracy and stability in the path tracking process of automated vehicles, a novel coordination control strategy for path tracking and stability of four-wheel steering and four-wheel independent driving (4WS-4WID) automated vehicles is proposed in this paper. The proposed control framework consists of a game theory-based upper controller and a torque distribution lower controller. The upper controller employs non-cooperative Nash game theory to derive a coordination control strategy based on a three-party game, aiming to investigate the interaction between Active Front Steering (AFS), Active Rear Steering (ARS), and Four-Wheel Independent Driving (4WID). The Nash equilibrium solution is obtained by solving the coupled Riccati equation within a linear quadratic differential game framework, which provides the front and rear wheel angles as well as yaw moment required for the path tracking process. The torques of four in-wheel motors are allocated by the lower controller through quadratic programming. To validate the effectiveness of the proposed approach, a joint simulation platform is constructed using CarSim/Simulink, and simulation tests are conducted. The results demonstrate that the coordination control strategy exhibits robust path tracking and lateral stabilization capabilities even under extreme operating conditions.