Compensation Approach to Error of Perpendicularity and Mismatch Error of Position Loop Gains in CNC Machine

Abstract

The contour precision has been an important CNC machine accuracy index along with the increase of high precision complex parts NC machining. The error of perpendicularity and the mismatch error of position loop gains among linked axes are regarded as the prime reasons to bring about CNC machine contour error. After analyzing the influence of the error of orthogonal axes perpendicularity to CNC machine contour precision, a compensation approach is set up that the following error is corrected in each sampling period, by introducing a perpendicularity deflection parameter. After analyzing the influence of the mismatch error of position loop gains to contour precision, a cross-coupled control approach based on interpolation dots is developed to enhance the matching degree among all of the linked axes. Finally, the developed compensation approaches are testified on a CNC experiment table. The experimentation results reveal that the developed compensation approaches are effective to enhance contour precision.