Non-linear decoupling control of vehicle plane motion

Abstract

This article studies the decoupling control strategies for a quasi-linearised vehicle model consisting of three degrees of freedom. The key feature of the model is that it preserves strong non-linearities and inherent coupling effects between longitudinal acceleration/braking force, steering angles and state variables of the vehicle, based on which two kinds of decoupling controllers are presented. Firstly, a control law for approximate decoupling of longitudinal, lateral and yaw motions is derived, which requires small control magnitude. Next, by selecting the virtual control inputs, a new input–output map is built, and the input–output decoupling controller is proposed. Furthermore, according to the characteristics of the vehicle model, an exponentially stable observer is designed. Several simulations are included to illustrate the proposed control scheme.