LU Di is a professor in the College of Mechanical and Electronic Engineering, Xi'an University of Architec- ture and Technology. His research interests include mechanical and electronic engineering and intelligent control, ludiland@ 126. com WANG Jian-xin is a postgraduate in the College of Mechanical and Electronic Engineering, Xi' an Uni- versity of Architecture and Technology. His research is on computer control. LI Jia-feng is a postgraduate in the College of Mechanical and Electronic Engineering, Xi'an University of Architecture and Technology. His research is on computer contol. TIAN Ye Working in the Sales Department of Sany Heavy Industries.