1. School of Automation, Northwestern Polytechnical University, Xi'an, China
2. Department of Engineering, King's College London, London, U.K.
3. Guizhou Aerospace Linquan Motor Company, Ltd., Guiyang, China
4. Xi'an Shuoyuan Optoelectronic Technology Company, Ltd., Xi'an, China
5. Department of Electrical Engineering, College of Engineering, University of Bisha, Bisha, Saudi Arabia