Controlled Motion of a Wheeled Three-Link Vehicle: Theory and Experiment

In this paper we examine the controlled motion of a three-link wheeled mobile robot on a horizontal plane. The motion of the system is induced by periodic oscillations of the outermost links relative to the central link in the horizontal plane. The dynamics of the robot is analyzed using two theoretical models. The first is a model of nonholonomic rolling which assumes motion without slipping at the points of contact. The second is a hybrid dynamical model which takes into account the possibility of alternation between nonholonomic rolling and motion with slipping along the axis of a wheel pair. An experimental investigation of the dynamics of the developed prototype with different controls is carried out. A comparative analysis is made of the data obtained in the course of a full-scale experiment and the results of numerical simulation based on both models considered. This comparative analysis is used to identify the limits of applicability of the nonholonomic model. It is shown that within these limits the nonholonomic model describes the real motion with good accuracy.