Research on the Control Strategy of Trailer Tracking Tractor for Articulated Heavy Vehicles

The purpose of this paper is to improve the path-following capability and high-speed lateral stability of the articulated heavy vehicles (AHVs). The six-axle heavy articulated vehicle was taken as the research object, in order to simplify the control design, the three-axle trailer of the articulated vehicles was simplified to a single-axle trailer. The Newton's second law was applied to the tractor unit and the single-axle trailer unit respectively, a three-degree-of-freedom vehicle yaw plane model was established, and its state space equation was derived. The trailer steering controller was designed by linear quadratic regulator (LQR) technique. At the same time, the optimal index function was determined by combining the vehicle state variables, and the optimal control input was obtained by using the algebraic Riccati equation. In order to achieve better control of the trailer unit, the relationship of the Ackerman steering geometry is used to obtain the ideal angle of each tire of the trailer unit. Co-simulation of low-speed steady circular motion and double lane change motion in Matlab/Simulink and Trucksim was carried out to verify the validity of the proposed vehicle model and the designed trailer steering controller. The simulation results show that the designed controller significantly improves the path following performance of the trailer unit and enhances the high-speed lateral stability.