Motorized vehicle active suspension damper control with dynamic friction and actuator delay compensation for a better ride quality

Abstract

This paper describes motorized active suspension damper control with dynamic friction and actuator delay compensation for an enhanced ride quality. The control algorithm consists of a supervisory controller, an upper-level controller and a lower-level controller. The supervisory controller determines the control modes, such as the passive control modes and the active control mode. The upper-level controller, which incorporates the existing actuator delay, computes the damping force using linear quadratic control theory. The actuator input is determined by the lower-level controller by compensating the dynamic friction torque. To estimate the sprung-mass displacement, the sprung-mass velocity, the unsprung-mass displacement and the unsprung-mass velocity, two state estimators are proposed. An adaptive observer is developed for the non-linear dry friction to estimate the ball-screw dynamic friction caused by the axial movement of the actuator and the viscosity. The performance of the proposed control algorithm was evaluated from simulations. It was shown from simulations that the proposed motorized active suspension damper control with a friction and delay compensation algorithm can improve the ride quality.