Bilinear Optimal Control of Semi-Active Suspension Taking Account of Coupled Vibration of Elastic Carbody and Truck

Abstract

Making a vehicle lightweight for high-speed often leads to reduction of flexural-rigidity of the body, and it brings about a problem that elastic vibration deteriorates ride quality with rigid body vibration. In addition to the rigid body vibration, it is also necessary to reduce the fundamental elastic mode of body bending vibration in order to achieve good ride quality. In this study, a FEM model is made by taking into consideration not only the rigid body dynamics, but also the elastic body vibration of a railway vehicle, and the effectiveness of semi-active suspension is examined for the elasticity vehicle. The semi-active suspension designed by the bilinear optimal control theory is used as a means of vibration reduction. The bilinear optimal control theory is applied to the suspension and it is compared with the skyhook control theory which has already been put into practice. As a result, it was shown that the bilinear optimal control theory reduces elantic vibration as well as rigid body vibration, while the skyhook control theory can reduce only rigid body vibration. Particularly, it was made clear that the semi-active suspension located at the truck can control the elastic vibration of vehicle body.