Disturbance Observer based Optimal Active Suspension Control for Vehicle-Trailer Systems

This paper presents an active suspension controller for a vehicle-trailer system aimed at improving ride comfort by accounting for the trailer’s effect. Previous studies have primarily focused on controller design for vehicles with active suspension systems alone. However, with the increasing number of drivers towing trailers, there is a growing need for an active suspension controller that considers disturbances caused by the trailer—without requiring additional sensors. In this work, trailer-induced disturbances are estimated using a disturbance observer based on a half-car model. The control input is determined through a combination of feedback control, using a linear quadratic regulator and feedforward control. The proposed algorithm was evaluated through simulation studies involving four consecutive bump scenarios. Simulation results demonstrated that the proposed algorithm effectively reduced vertical acceleration caused by the trailer when compared to baseline algorithms.