**Author details**

Yiming Wu1,2\*, He Chen1,2 and Tong Yang1,2

\*Address all correspondence to: wuyiming\_1@126.com

1 Institute of Robotics and Automatic Information Systems, College of Computer and Control Engineering, Nankai University, Tianjin, China

2 Tianjin Key Laboratory of Intelligent Robotics, Nankai University, Tianjin, China
