1. Mechanical Engineering Department, Shandong University, Jinan, China
2. Inria, CNRS, Centrale Lille, UMR 9189 CRIStAL, University of Lille, Lille, France
3. IntelliSobot Technology (IST) Company Ltd., Suzhou, Jiangsu, China
4. Control Science and Engineering Department, Shandong University, Jinan, China