1. School of Civil Engineering, Qingdao University of Technology, Qingdao 266520, P. R. China
2. School of Information and Control Engineering, Qingdao University of Technology, Qingdao 266520, P. R. China
3. Beijing Key Laboratory of Traffic Engineering, Beijing University of Technology, Beijing 100124, P. R. China
4. CRRC Qingdao Sifang Co., LTD, Qingdao 266111, P. R. China
5. School of Rehabilitation Sciences and Engineering, University of Health and Rehabilitation Sciences, Qingdao 266113, P. R. China