Attitude Stabilization of Dynamically-Stable Four-Wheeled Vehicle with Independent Suspension

Abstract

This paper deals with a dynamically-stable personal vehicle which is driven by four omnidirectional wheels. It has two distinctive mechanical structures. First, the vehicle body is connected to the chassis with a single universal joint. Though the body is inherently unstable, once it is stabilized by an appropriate feedback controller, the posture is always maintained upright while driving, even on sloping surface. Secondly, four wheels are elastically supported by independent suspension for traveling on rough road. It causes additional oscillatory dynamics in the closed-loop system which must be explicitly taken into account in the controller design. The overall mechanical structure, its kinematic and dynamic models, derivation of the controller are described.