In the area of precision engineering industries, high performance positioning precision machines are increasingly employed to improve the productivity and to lower the manufacturing cost. In many applications such as actuaphotonics or biomedical products, there are increasingly demands for machines that have positioning accuracy of several micrometers. In this paper, we present a prototype precision machine that has a positioning accuracy of 1 /spl mu/m and a peak speed above 1 m/s. The precision positioning machine uses a three phase permanent magnet linear motor as the actuator. As it is capable of producing linear motion directly, it eliminates the needs of mechanical transmission from the rotary to the linear motion. High closed loop performance has been achieved by using a state space based model predictive controller and a dynamic friction compensation system. The friction and the control system have been optimally identified and tuned using the genetic algorithm. Experimental results have verified the effectiveness of the developed approach.
['K. H. Low', 'Meng-Teck Keck']
A high performance precision machine