1. Electrical and Electronic Engineering, Xi'an Jiaotong-Liverpool University, Suzhou, China
2. Mechatronics and Robotics, Xi'an Jiaotong-Liverpool University, Suzhou, China
3. College of Electrical Engineering, Zhejiang University, Hangzhou, China
4. University of Liverpool, Liverpool, U.K.
5. School of Urban Railway Transportation, Soochow University, Suzhou, China