1. School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, China
2. State Key Laboratory of Synthetical Automation for Process Industries, Northeastern University, Shenyang, China
3. Department of Engineering, King's College London, London, U.K.
4. Parallel Robot and Mechatronic System Laboratory of Hebei Province, Yanshan University, Qinhuangdao, China