Cooperative Strategy of Trajectory Tracking and Stability Control for 4WID Autonomous Vehicles Under Extreme Conditions

Trajectory tracking and stability control are two essential functions of autonomous vehicles, and there is inevitable mutual interference between them, especially under extreme conditions. Towards addressing this challenge, this paper proposes a novel cooperative strategy of trajectory tracking and stability control for four-wheel independent drive (4WID) autonomous vehicles. An adaptive trajectory tracking controller is designed based on the model predictive control (MPC) theory, in which the tire cornering stiffness is modified in real-time leverages the lateral force estimated by the square-root cubature Kalman filter (SCKF). Then, the vehicle stability controller is designed based on the sliding mode control (SMC), in which the tire force saturation constraint and the relative weight of yaw rate and sideslip angle are considered. Furthermore, a weight adaptive criterion with normalized stability index is defined to develop the cooperative strategy of trajectory tracking and stability control. The feasibility and adaptability of the proposed method to different extreme conditions are verified by hardware-in-the-loop (HIL) test and CarSim-Simulink co-simulation. Finally, an experimental case is presented to demonstrate the realizability of the proposed method.

Automated summary

This paper proposes a novel cooperative strategy for trajectory tracking and stability control of four-wheel independent drive (4WID) autonomous vehicles. An adaptive trajectory tracking controller is designed using the model predictive control (MPC) theory, which modifies the tire cornering stiffness in real-time based on the estimated lateral force. A vehicle stability controller is then designed based on sliding mode control (SMC), considering tire force saturation constraint and relative weight of yaw rate and sideslip angle. The feasibility and adaptability of the proposed method are verified through hardware-in-the-loop (HIL) test and CarSim-Simulink co-simulation. An experimental case is presented to demonstrate the realizability of the proposed method.