1. School of Computer and Communication Engineering, Northeastern University at Qinhuangdao 1 , Qinhuangdao 066004, China
2. School of Control Engineering, Northeastern University at Qinhuangdao 2 , Qinhuangdao 066004, China
3. Beijing Jiaotong University, School of Electrical Engineering 3 , Beijing, China
4. Beijing Engineering Research Center of Electric Rail Transportation 4 , Beijing, China