Dual-mode switched control of suspension with consideration of actuator dynamics

This work developed a dual-mode switched active control suspension to improve ride comfort and enhance anti-roll performance. First, a 4-DOF roll-plane half-car model, with consideration of the non-linear characteristics of hydraulic actuator, was employed for the study. On the basis of the backstepping algorithm, the controller was designed with two states corresponding to ride comfort control and anti-roll control. Accordingly, the controller can switch between the active suspension system (ASS) mode and the active hydraulically interconnected suspension (AHIS) mode. Subsequently, a trajectory planning function for the body roll angle was adopted to ensure a smooth switching process and desired value tracking. To estimate the critical states required for the control algorithm, the authors applied state observation based on the unscented Kalman filter (UKF). Then, simulation and road testing were undertaken to evaluate the performance of the UKF-based observation. Finally, numerical simulations, including step input and the fishhook test, were carried out to illustrate the effectiveness of the presented approach.