1. Beijing Key Laboratory of Performance Guarantee on Urban Rail T ransit Vehicles, School of Machine-electricity and vehicle Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China
2. School of civil engineering and survey, Beijing polytechnic college, Beijing 100044, China
3. State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084, China
4. School of Humanity and Law, Beijing University of Civil Engineering and Architecture, Beijing 100044, China