1. Department of Cognitive Robotics, Delft University of Technology, Delft, The Netherlands
2. School of Science and Engineering, Chinese University of Hong Kong (Shenzhen), Shenzhen Institute of Artificial Intelligence and Robotics for Society, Shenzhen, China
3. UBTECH Robotics Corporation, Shenzhen, Guangdong, China
4. School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei, China
5. Humanoids and Human Centered Mechatronics Research Line of Istituto Italiano di Tecnologia (IIT), Genova, Italy
6. School of Computing, University of Leeds, Leeds, U.K.