Velocity Following Control of a Pseudo-Driven Wheel for Reducing Internal Forces Between Wheels

Abstract

The coordination of multiple driving wheels is an important issue in wheeled mobile robot design, for both maximizing tractive capability and optimizing energy consumption. This study converts a driving wheel into a pseudo-driven wheel (PDW), which is controlled to follow the motion of the robot body, in accordance with the kinematic constraints. To eliminate the internal force conflicts between wheels, a velocity following control (VFC) method is proposed to control the PDW in the presence of force disturbance caused by soil distortion during wheel-terrain interaction. The feasibility of the PDW conversion and the proposed control method are experimentally demonstrated. Compared with the inverse kinematics control (IKC) method, the rover using PDW with VFC is shown to be capable of more accurate straight and steering path following on soft terrain, reducing internal forces between wheels by more than 70% in the experiments.