1. School of Automation and the Guangdong-HongKong-Macao Joint Laboratory for Smart Discrete Manufacturing, Guangdong University of Technology, Guangzhou, China
2. College of Electrical and Information Engineering and the National Engineering Laboratory for Robot Visual Perception and Control, Hunan University, Changsha, China
3. School of Computer Science and Engineering, South China University of Technology, Guangzhou, Guangdong, China