1. Nagamori Institute of Actuators, Faculty of Engineering, Kyoto University of Advanced Science , 18 Yamanouchi-Gotandacho , Ukyo-ward , Kyoto, 615-8577 , Japan
2. Department of Mechanical and Electrical Systems Engineering, Faculty of Engineering, Kyoto University of Advanced Science , 18 Yamanouchi-Gotandacho , Ukyo-ward , Kyoto, 615-8577 , Japan