1. Robotics and Autonomous Systems Thrust, The Hong Kong University of Science and Technology (Guangzhou), Guangzhou, China, also with the Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong SAR, China, and also with the HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Futian, Shenzhen 518000, China.
2. Department of Electrical and Computer Engineering, National University of Singapore, Singapore 119077.
3. Automation and Robotics Research Institute, The University of Texas at Arlington, Arlington, TX 76118 USA.