1. Department of Mechanical and Control Engineering, Kyushu Institute of Technology, 1-1 Sensui, Tobata, Kitakyushu, Fukuoka 8048550, Japan
2. Graduate School of Information Sciences, Applied Information Sciences, Information and Applied Technology, Human–Robot Informatics, Tohoku University, 6-6-01 Aramaki Azaaoba, Aoba, Sendai 9808579, Japan