Stability Analysis of a Closed-loop Articulated Vehicle System with Trailer Active Steering based on LQR Control

This paper presents an LQR-based trailer active steering control method to enhance the dynamic stability of the articulated vehicle system. As a typical articulated vehicle, a car-trailer combination (CTC) is studied. A 3DoF (degree of freedom) single-track model is established. The control objective is to optimize the critical state of CTCs to the steady-state condition, and the steering angle of the trailer is the input. The simulation result shows that the trailer's active steering can rapidly reduce the yaw rate of CTCs under the original dynamic critical speed. The yaw damping ratio of the closed-loop system increases from 0 to 0.68, in which the stability of the dynamic is fully guaranteed.