1. School of Mechanical Engineering, Southwest Jiaotong University , Chengdu, 610031 , China
2. Technology and Equipment of Rail Transit Operation and Maintenance Key Laboratory of Sichuan Province , Chengdu, 610031 , China
3. Department of Mathematics, Auburn University Montgomery , Montgomery, AL 36124-4023 , USA
4. Hunan Special Equipment Inspection and Testing Institute , Changsha, 410117 , China