Tracking control of a spherical inverted pendulum with an omnidirectional mobile robot

This paper considers the problems of design and implementation of trajectory tracking control of a spherical inverted pendulum with an omni-directional mobile robot. The control objective is to control the robot to track the desired translational trajectory with desired orientation while maintaining the inverted pendulum in its upright position. The mathematical models of the spherical pendulum and omnidirectional mobile robot are given to facilitate the control analysis and design. Based on linear output regulation, and inverse dynamics, a tracking controller is designed to achieve asymptotic trajectory and orientation tracking. The designed control law is implemented on a digital signal processor and tested on an experimental apparatus. The effectiveness of the designed control scheme is validated through experimental studies. The results show that the robot is able to track the reference trajectory and reference orientation while balancing the inverted pendulum.