Direct drive XY table based on real-time position compensation and repetitive control

The contour accuracy of direct drive XY table driven by the permanent magnet linear synchronous motor (PMLSM) is influenced for time-varying free-form contour following task, end effect and friction of the XY table. To enhance the contouring performance, contour error algorithm applicable for multi-axis nonlinear motion system was adopted. Position error compensator (PEC) was combined to make the contour error approach to zero. A compound control scheme base on combining repetitive controller (RC) and a pseudo derivative feedback with feed-forward (PDFF) speed controller were employed in this paper. Theoretical analysis and simulation results show that the designed control system make XY table possess high performance of contour accuracy and reduce the influence of the periodic disturbances of XY table system.