1. School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
2. Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education, Tianjin University, Tianjin 300072, China;
3. School of Mechanical Engineering, Tianjin University, Tianjin 300072, China
4. School of Mechanical Engineering, Tianjin University, Tianjin 300072, China e-mail:
5. Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC 3122, Australia