[1] Univ Sci & Technol Beijing, Sch Automat & Elect Engn, Beijing 100083, Peoples R China
[2] Univ Elect Sci & Technol China, Sch Automat Engn, Chengdu, Sichuan, Peoples R China
[3] Univ Elect Sci & Technol China, Ctr Robot, Chengdu, Sichuan, Peoples R China
[4] Beihang Univ, Sch Automat Sci & Elect Engn, Beijing, Peoples R China