Abstract
A stabilizing control law is obtained for a pendulum whose weight can be moved based on a condition for suppressing vibrations of the swing derived by an energy-based method, and experiments are performed to examine the usefulness of the controller. The controller is realized by a servo system for the position of the weight that simply consists of a second-order lag and a bang-bang reference input obtained from the pendulum trajectory. The control system approaches the optimal one that minimizes the damping ratio of the pendulum when the time constant of the servo system approaches zero. The results of experiments show the effectiveness of the proposed method.