1. College of Electronic and Information Engineering, Tongji University, Shanghai 201804, China
2. Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University, Shanghai 201804, China
3. Institute of Rail Transit, Tongji University, Shanghai 201804, China
4. Shanghai University of International Business and Economics, Shanghai 201620, China
5. Faculty of Mathematics and Physical Sciences, University College London, WC1E 6BT, London, UK