1. Key Laboratory of Advanced Manufacturing and Intelligent Technology, Ministry of Education, Harbin University of Science and Technology, Harbin, P. R. China
2. Qiqihar Heavy CNC Equipment Corp. Ltd., Qiqihar, P. R. China
3. School of Electrical and Mechanical Engineering, Qiqihar University, Qiqihar, P. R. China
4. Qiqihar First Machine Tool Factory Corp. Ltd., Qiqihar, P. R. China