1. School of Automation and Intelligence, Beijing Jiaotong University, Beijing, People's Republic of China
2. Engineering and Natural Sciences, Technische Hochschule Wildau, Wildau, Germany
3. Baotou Railway Vocational & Technical College, Baotou, People's Republic of China
4. National Engineering Research Center of Rail Transportation Operation and Control System, Beijing Jiaotong University, Beijing, People's Republic of China