1. Robotics and Automation Team, Guangdong Institute of Automation, Guangzhou, Guangdong, 510070, P. R. China
2. Biomimetic and Intelligent Robotics Laboratory, School of Mechanical and Automotive Engineering, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
3. Department of Computing Science, University of Alberta, Edmonton, AB, T6G 2E8, Canada
4. School of Electronic and Information Engineering, South China University of Technology, Guangzhou, Guangdong, 510640, P. R. China