1. School of Electromechanical Engineering, Beifang University of Nationalities, Yinchuan, Ningxia, China
2. School of Information and Communication Engineering, North University of China, Taiyuan, Shanxi, China
3. School of Mechanical Engineering, Taiyuan University of Science and Technology, Taiyuan, Shanxi, China
4. State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University, Xi'an, Shaanxi, China