1. Yangzhou Polytechnic Institute, Yangzhou 225127, China
2. Department of Electrical Engineering, Yangzhou University, Yangzhou 225127, China
3. College of Automation, Jiangsu University of Science and Technology, Zhenjiang 215600, China
4. Program of Intelligence and Control, Cluster of Electronics and Mechanical Engineering, School of Science and Technology, Gunma University, Kiryu 376-8515, Japan