1. Associate Professor, College of Mechatronic Engineering, North Univ. of China, Xueyuanlu 3, Taiyuan 030051, China (corresponding author).
2. Ph.D. Candidate, College of Mechatronic Engineering, North Univ. of China, Xueyuanlu 3, Taiyuan 030051, China.
3. Civil Engineer, Academy of Military Sciences, Academy of Defense Engineering, Changyonggong 15, Beijing 100850, China.
4. Professor, Dept. of Astronautic Science and Mechanics, Harbin Institute of Technology, Xidazhijie 92, Harbin 150001, China.