Application of an Iterative Learning Control Algorithm to Volumetric Error Compensation for CNC Machines

Abstract

To promote higher-quality machining, this paper presents a software-based method for compensating for volumetric errors. The developed software compensation method modifies CNC part programs by applying previously obtained volumetric error tables to modify the axial motion commands. Furthermore, iterative learning control is employed to repetitively and precisely calculate these modified motion commands and further reduce any newly generated volumetric errors that deviate from the machining contours described by the CNC part programs. Several experiments and simulations were performed on a commercial CNC milling machine to validate the approach developed in this study. The results of the experiments indicate that volumetric errors are significantly reduced by applying the developed software compensation method. The rate of reduction was 77.99% for a tested circular contour and 87.59% for a tested spiral contour; therefore, the feasibility of the developed software compensation method was successfully validated for volumetric error compensation for CNC machines.

Influence Analysis of Geometric Error and Compensation Method for Four-Axis Machining Tools with Two Rotary Axes

“…The error compensation experiments were performed on a linear machine tool. Lu et al [32] suggested a software-based method for compensating volumetric errors and modifying CNC part programs through the application of previously obtained volumetric error tables to modify the commands. Experiments were conducted, and the rate of reduction was found to be 77.99% for a tested circular contour and 87.59% for a tested spiral contour.…”