2012 Volume 25 Issue 2 Pages 28-38
This paper considers power assist control methods for periodic motions. 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 in the sense of energy efficiency. Therefore, we propose power assisting methods to suppress the velocity fluctuation similar to the repetitive control. We compare the effectiveness and the energy efficiency of each method through numerical simulation and experiments.