1. School of Automotive and Traffic Engineering, Jiangsu University, Zhenjiang 212013, P. R. China
2. Chongqing Key Laboratory of Urban Rail Transit System Integration and Control, Chongqing 400074, P. R. China
3. Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Kow-loon, Hong Kong, P. R. China
4. College of Engineering, China Agricultural University, Qinghuadonglu No.17, HaiDian District, Beijing 100083, P. R. China
5. State Key Laboratory of Intelligent Agricultural Power Equipment, Luoyang 471039, P. R. China
6. Luoyang Tractor Research Institute Co. Ltd., Luoyang 471039, P. R. China