Coordinated Adaptive Robust Contour Tracking of Linear-Motor-Driven Tables in Task Space

In order to improve the overall contouring performance, it appears that it is no longer possible to neglect dynamic coupling phenomena that occur during contour tracking, especially for linear motor systems which often move at high speed. This paper studies the high performance contour tracking control of linear-motor-driven tables. The table dynamics is first transformed into a task coordinate frame. A discontinuous projection based adaptive robust controller (ARC) which explicitly takes into account the dynamic coupling effect is constructed to improve the contouring performance under both parametric uncertainties and uncertain nonlinearities. A desired compensation ARC scheme is also presented, in which the regressor is calculated using desired contour information only. Both schemes are implemented and compared on a linear-motor-driven X-Y table.