I. Introduction
As ONE of the most important function for multiaxis motion system represented by a computer numerical controlled (CNC) machine tool, contour following can coordinate all the axes of the motion system to complete the processing of the desired contour [1], [2]. It is of great practical significance for multiaxis motion systems to achieve great contouring following performance. Contouring error, which is defined as the deviation between the contour formed by the actual motion control and the desired contour, is the most intuitive indicator of the contouring performance [3]. Generally, the contouring error can be reduced indirectly through the improvement of the tracking precision of each axis [4]. In recent years, with the development of power electronic drive technology, more and more advanced motion control algorithms, such as learning adaptive robust control [12], [13], model predictive control [5], [6], repetitive control [7], cascade control [8], [9], and data-driven control [10], [11], have been successfully applied to practical industry to improve the contouring performance of multiaxis systems. However, since the dynamic characteristics of each axis in the multiaxis system will inevitably be mismatched in practical applications, simply improving the tracking accuracy of each axis may not guarantee the reduction of contouring error [14].