1. School of Advanced Manufacturing, Guangdong University of Technology, Jieyang, China
2. School of Electromechanical Engineering and State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, Guangdong University of Technology, Guangzhou, China
3. School of Electronic and Information Engineering, Guangdong Ocean University, Zhanjiang, China
4. Electrical Engineering, National Cheng Kung University, Tainan, Taiwan, China