Parameter identification and controller optimization using GA for a precision stage

In this paper, we present the optimization of the performance of a precision motion control system which has a positioning accuracy of 1 μm. The system uses a permanent magnet DC linear motor as the actuator to provide a smooth direct force. As the friction has a deteriorating effect on the performance of the precision stage, various experiments have been conducted and data are used to identify the friction parameters using GA. To achieve fast and accurate servo response, we use the GA to optimize a state space predictive controller with a dynamic friction compensation scheme for the control system. Experimental results are presented to demonstrate the good performance of our prototype system.