1. Frontier Science and Technology Research Center, Guangzhou Institute of Advanced Technology, Guangzhou 511458, China
2. School of Engineering Science, University of Chinese Academy of Sciences, Beijing 100049, China
3. School of Intelligent Manufacturing, Chengdu Technological University, Chengdu 611730, China
4. School of Construction Machinery, Chang’an University, Xi’an 710064, China
5. Department of Robot Engineering, Hanyang University, Ansan 426-791, Republic of Korea