Chapter 8 - Multiple-DOF active seat suspension

Abstract

The heavy duty vehicles are generally working under severe conditions, where the uneven road can cause roll vibration and vertical vibration of the vehicle body and can affect seat suspension. The conventional single-degree of freedom (single-DOF) seat suspension can only isolate the vertical vibration while it transfers the roll vibration to the driver’s body. The high magnitude of driver body’s lateral acceleration caused by roll vibration will influence drivers’ health and ride comfort. In this chapter, we introduce a two-layer multiple-DOF active seat suspension which has a z-axis DOF in the bottom layer and a roll DOF in the top layer. A non-singular terminal sliding controller is designed to control the top-layer to reduce the lateral acceleration and roll acceleration by tracking the desired roll angle. An H∞ controller with disturbance compensation is applied to control the bottom-layer for vertical vibration isolation. Both controllers use the variables which can be measured or estimated in the practical application as feedback signals. The proposed vibration isolation method can effectively reduce the whole-body vibration (WBV) of heavy duty vehicle drivers, and it shows high potential for practical application.