Control of the motorized active suspension damper for good ride quality

Abstract

This paper presents a control algorithm for the motorized active suspension damper. The control algorithm consists of supervisory, upper-level and lower-level controllers. The supervisory controller determines the control modes, such as the passive mode, the roll mode and the body acceleration mode. The upper-level controller computes the damping force using linear quadratic control theory. The actuator input is determined by the lower-level controller. Three state estimators, namely the vehicle body’s velocity estimator, the suspension state estimator and the friction estimator, are proposed to estimate the sprung-mass and unsprung-mass velocities, the tyre deflection, the roll angle, the roll rate and the friction. The performance of the proposed control algorithm was evaluated via simulations and vehicle tests. It was shown from both simulations and vehicle tests that the proposed control algorithm can improve the ride quality using a motorized active suspension damper.