1. School of Mechanical Engineering, Anhui Polytechnic University 1 , Wuhu 241000, China
2. Wuhu Ahpu Robot Technology Research Institute Co., Ltd. 2 , Wuhu 241000, China
3. National Key Laboratory of Science and Technology on Helicopter Transmission, Nanjing University of Aeronautics and Astronautics 3 , Nanjing 210016, China
4. Zhejiang Fine Motion Robot Joint Technology Co., Ltd. 4 , Yuhuan 317600, China
5. School of Mechanical Engineering, Zhejiang University 5 , Hangzhou 310058, China