1. Institute of Robotics and Intelligent Manufacturing and School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, China
2. School of Automation and Electrical Engineering, Shenyang Ligong University, Shenyang, China
3. School of Computing, University of Portsmouth, Portsmouth, U.K.
4. State Key Laboratory of Robotics, Shenyang Institute of Automation, Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang, China