Integrated controller design for automotive semi-active suspension considering vehicle behavior with steering input

This study aims at achieving simultaneous realization of ride comfort and steering stability in the controller design for semi-active suspension considering the most sensitive frequency range of human body and vehicle behavior at steering. In this study, a method which can improve both the ride comfort and the vehicle stability is proposed by separating the control range in terms of frequency domain, where the frequency weightings on the controlled variables are used. Furthermore, the controller is scheduled in time domain in order to realize the positive pitch angle mode at the slalom. In this study, the dynamics of road disturbance is supposed and is accommodated into that controller to make the control performance more effective. In order to investigate the effectiveness of the proposed control system, the computer simulations are carried out by using a full vehicle model which has variable stiffness and damping semi-active suspension system. As a result, it is demonstrated that the proposed method can realize improving the ride comfort, reducing the vehicle motion, and synchronizing the roll and pitch angles caused by steering.