Design and Modeling of a Dual-Ball Self-Balancing Robot

In this letter, a novel dual-ball self-balancing robot is proposed for the first time. Different from the operating principle of the traditional single-ball self-balancing robot, the dual-ball robot can achieve flexible variable-axis rotations though the differential motions of the two balls, and overcome the drawbacks of single-ball self-balancing robots such as large mass of the ball and low dynamic response of robot. The kinematics of the dual-ball robot including front and rear balls, main body and the omni-wheels are formulated analytically, together with the dynamic model. Subsequently, the motion control scheme of the dual-ball robot is also developed by considering both balancing control and motion control. Following that, numerical simulations are conducted to validate the control scheme. One research prototype is developed, and experiments are carried out to evaluate the design concept and theoretical models of the dual-ball self-balancing robot.