Passivity-based control of an omnidirectional mobile robot

This paper studies passivity-based trajectory tracking control of an omnidirectional mobile robot. The proposed control design is simple to be implemented in practice, because of an effective exploitation of the structure of robot dynamics. First, the passivity property of the prototype robot is analyzed. Then the control system is designed based on the energy shaping plus damping approach. We find that the prototype robot itself has enough damping forces. As a result, only energy shaping is needed in our proposed controller, while the damping injection is unnecessary for our robot. In other words, the disadvantages of differential feedback, such as amplifying the measurement noise, can be avoided. Globally asymptotic stability is guaranteed. Both simulations and experimental results show the effectiveness of the proposed control design.