1. Department of Mechanical and Electrical Engineering, North China University of Technology, Beijing 100144, China
2. State Key Laboratory of Multimodal Artificial Intelligence Systems, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
3. Department of Orthopaedics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China
4. Faculty of Information Technology, Beijing University of Technology, Beijing 100124, China