1. School of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou, China
2. The State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, China
3. Chair of Mechanics and Robotics, University of Duisburg-Essen, Duisburg, Germany
4. Robotics Research Center, Yanshan University, Qinhuangdao, China