Path tracking of autonomous vehicle with consideration of vehicle stability in sideslip angle phase plane

Abstract

In current research of autonomous vehicle path tracking, most contributions focus on tracking accuracy during complex driving condition. However, the vehicle might fall into unstable dangerous condition when the road curvature is big or with high speed. A path tracking control framework is proposed in this paper, which considers path tracking accuracy and vehicle stability. In general, the control framework consists of three main components: vehicle stability judging controller, path tracking controller, and torque distributor. Firstly, the stability of the current vehicle can be evaluated by the stability judgment controller according to the phase plane of the sideslip angle. Then, the proportion of vehicle stability in the control objective is adjusted according to the current vehicle stability. To improve the path tracking accuracy, the path tracking is composed of a combined controller using MPC algorithm, which controls the front wheel angle and direct yaw moment at the same time. After that, the torque distributor is developed to distribute the desired yaw moment into four executive wheels, which synthesizes the results of power performance distribution and stability distribution. Finally, the effectiveness of the proposed control framework is verified by the Matlab-CarSim co-simulation experiment and the hardware-in-the-loop experiment based on LabVIEW-RT. The results show that the proposed controller has better tracking accuracy and stability than the general MPC controller.