Balancing of an inverted pendulum with a redundant direct-drive robot

This paper addresses the problem of stabilizing a base-excited inverted pendulum around its upright position with a robot. The pendulum has two rotational degrees of freedom and its base point is moved in two-dimensional space by a planar direct-drive robot. The robot has three degrees of freedom and its kinematic redundancy occurring at the inverse kinematics is utilized to optimize the joint acceleration and the manipulability measure. A decentralized joint acceleration control with a software velocity/acceleration observer, is used to accelerate/decelerate each joint of the robot to balance the pendulum. Experimental results are described to show the stable and robust responses of the control system