TRACKING ERRORS DECREASING IN CNC SYSTEM OF MACHINE TOOLS

In the paper the procedures and practical methods of tracking errors compensation in servo-drives are considered. The PID controllers of servo-drives do not decrease tracking errors enough in the case of fast changes of the motion velocity. The good method of decreasing of the tracking errors in cascade servo-drives is to use the feedforward command and feedforward friction compensation. The exemplary results of the test of CNC system based on servo-drives with PMSM motors with proposed control method including the on-line calculation of feedforward loops parameters are presented.