1. Liaoning Key Laboratory of Information Physics Fusion and Intelligent Manufacturing for CNC Machine, Shenyang Institute of Technology, Shenfu New District 113122, Fushun, Liaoning, P. R. China
2. School of Automation and Electrical Engineering, Shenyang Ligong University, No. 6, Nanping Middle Road, Hunnan District, Shenyang City, Liaoning Province 110159, P. R. China
3. Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, UK
4. Department of Computer Science, University of Bradford, Bradford, U. K.
5. Department of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL, U. K.