Modeling and Control Design for Active Trailer Steering of Heavy Vehicles

This paper presents a linear quadratic regulator (LQR) controller for active trailer steering (ATS) of a tractor-semitrailer. The tractor-semitrailer is modelled as a linear yaw/roll model with 5 Degrees-Of-Freedom (DOF). The linear yaw/roll model is validated with a nonlinear tractor-semitrailer model developed with TruckSim under a simulated single lane-change maneuver. Then, the validated linear yaw/roll model is used to design the LQR controller for ATS. The TruckSim model and the LQR controller are integrated by means of an interface between the software packages of TruckSim and Matlab/Simulink. The LQR controller is assessed using numerical simulation of the TruckSim model with and without the ATS control. Evaluation of the controller is based on the performance measures of the trailer in terms of rearward amplification (RA), peak roll angle, and load transfer ratio (LTR). It is demonstrated that the LQR controller leads to the decrease the peak values of the aforementioned measures by 4.81%, 20.7%, and 33%, respectively.