Semi-active suspension control system design for vibration reduction of passenger's body based on lissajous figure of damping force

In recent years, it is reported that passenger's dynamics and sensibility are different from a driver. However, there are few researches about a suspension control which considers the dynamics of human body, and a sitting position. In this paper, new semi-active suspension control logic is developed to reduce passenger's vibration and motion. First, a vehicle and passenger model including the dynamics of human body and the sitting position is constructed. Second, robust control system design method which uses the vertical acceleration of a passenger's head as one of controlled value, is proposed. In order to control the jerk which is generated by changing of a damping coefficient rapidly, the robust controller is designed based on Lissajous figure of damping force. From the result, it was confirmed that in nearly the resonance frequency of vertical direction of the passenger's head, the proposed control method can reduce the passenger's vibration better than general control methods which use a vertical acceleration of the vehicle body as the controlled value.