Energy-efficient power assisting methods for periodic motions and its experimental verification

This paper considers power assist control methods for periodic motions in a steady-state. In most power assist applications, additional force is applied in proportion to the instantaneous value of force generated by human. However, human persistent tasks are sometimes periodic and it can be shown that the proportional assist is not optimal for such motions. Therefore, we propose power assisting methods to suppress the velocity fluctuation similar to the repetitive control. By monitoring an energy consumption, we compare the effectiveness and the energy efficiency of each method through experiments.