1. Tianjin University Key Laboratory of Mechanism Theory and Equipment Design of the Ministry of Education, Centre for Advanced Mechanisms and Robotics, , Tianjin 300350 , China
2. Southern University of Science and Technology Institute for Robotics, , Shenzhen 518055 , China ;
3. King’s College London Centre for Robotics Research, , London WC2R 2LS , UK ;
4. Tianjin University Key Laboratory of Mechanism Theory and Equipment Design of the Ministry of Education, , Shenzhen 518055, China