Funding for this research was provided by:
National Natural Science Foundation of China (61305102)
Open Foundation of the State Key Laboratory of Robotics and System (SKLRS-2013-MS-02)
the fifty-fourth batch of China Postdoctoral Science Fund (2013M540247)
Article History
Received: 24 May 2018
Accepted: 9 November 2018
First Online: 20 November 2018