Tracing control for a tracked vehicle based on a virtual wheeled mobile robot

Abstract

Although a tracked vehicle enables stable movements on rough terrain, in a rotating motion no fixed kinematic model such as the model of wheeled mobile robot exists. Hence, it is difficult to realize a autonomous driving control of the tracked vehicle. In this paper, a new tracking control method for a tracked vehicle is described. The proposed method is constructed by using a virtual wheeled mobile robot. A instantaneous motion of the vehicle with slip can be regarded as a motion of a mobile robot with independent driving wheels. From the kinematic constraints, the virtual mobile robot model is derived. The virtual desired trajectory for the virtual robot is obtained from the given desired trajectory for the original tracked vehicle under the assumption that the virtual model is fixed. A control rule is derived by applying a differential feedback control method for wheeled mobile robots, and guarantees that the virtual mobile robot follows the virtual desired trajectory. We also describe a on-line prediction method for the virtual robot so as to discard the assumption that the virtual model is fixed.