1. College of Information and Electrical Engineering, China University of Mining and Technology, Jiangsu, Xuzhou 221116, China e-mail:
2. Graduate School of Natural Science and Technology, Okayama University 3-1-1 Tsushimanaka, Okayama 7008530, Japan e-mail:
3. Graduate School of Engineering, University of Fukui, Fukui 9108507, Japan e-mail:
4. School of Mechatronics Engineering and Automation, Shanghai University, 149 Yanchang Road, Shanghai 200072, China e-mail: