Optimal control of the automatic steering system

Optimal control-based automatic steering system regardless of steering actuator dynamics for autonomous ground vehicle might be unstable for real vehicle implementation. This paper analyzes such an unstable phenomenon and gives solution to the problem through selection of appropriate optimal control matrix. Firstly, a new kind of the vehicle-road lateral dynamic model with look-ahead action is established and the steering controller for path tracking is developed based on the optimal control theory with regardless of steering actuator dynamics. Then, combining with the steering actuator dynamics, the unstable phenomenon is introduced and analyzed for real vehicle implementation. A novel solution to overcome the unstable phenomenon is proposed. Simulation results show that the proposed automatic steering optimal controller is useful and achievable for real vehicle implementation.