1. Research Institute of Intelligent Control and Systems; Harbin Institute of Technology; Harbin 150080 China
2. School of Electrical and Electronic Engineering; Nanyang Technological University; 639798 Singapore
3. College of Automation; Harbin Engineering University; Harbin 150001 China
4. College of Engineering and Science; Victoria University; Melbourne 8001 Vic. Australia
5. School of Machinery and Automation; Wuhan University of Science and Technology; Wuhan 430081 China