Dynamics modelling and stable motion control of a Ballbot equipped with a manipulator

Human-Robot physical interaction is an important attribute for robots operating in human environments. A Ballbot is an under-actuated system with nonholonomic dynamic constraints. It is a skinny robot with a small base that helps the robot to move in limited space. It is as tall as human height until could interact by people whereas a Ballbot has not been equipped with a manipulator. This manipulator adds new advantages to the Ballbot such as object manipulation and grasping. In this paper and to achieve more performance of a Ballbot, it is equipped with a PUMA type manipulator which gives to the proposed robot the capability of better stabilization. To this end, dynamics equations of the assumed mobile robot is presented and verified. Then, by respecting to this fact that a Ballbot is in the class of under-actuated systems, a control algorithm is proposed to attain the stable motion control of the system. Finally, a simulation routine is performed to move along the desired path/trajectory. Obtained results reveal the merits of the verified model of the new Ballbot and the considered control algorithm which will be discussed.