Funding for this research was provided by:
Foundation for Innovative Research Groups of the National Natural Science Foundation of China (51521003)
National Natural Science Foundation of China (51675123, 61603112)
Self-Planned Task of State Key Laboratory of Robotics and System (SKLRS201603B)
Article History
Received: 28 June 2017
Accepted: 13 February 2018
First Online: 5 March 2018