1. Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, Hong Kong
2. College of Automation Engineering, Nanjing University of Aeronautics and Astronautics (NUAA), Nanjing, Peoples' Republic of China
3. School of Automation, Nanjing University of Science and Technology, Nanjing, Peoples' Republic of China
4. School of Automation, Guangdong University of Technology, Guangzhou, Peoples' Republic of China