1. School of Electrical Engineering and Automation, Anhui University, Anhui, China
2. School of Electrical Engineering, Xi’an University of Technology, Xi’an, China
3. School of Electronic Information Engineering, Xi’an Technological University, Xi’an, China
4. School of Electrical and Electronic Engineering, Nanyang Technological University, Jurong West, Singapore
5. Department of Automation, University of Science and Technology of China, Hefei, China