Contouring performance measurement and evaluation of NC machine controller for virtual machining CAM system

Abstract

To realise a virtual machining CAM system the machine tol accuracy together with the controller behaviour should be incorporate in the CAM system. For such a a purpose a ball-bar method is presented for measuring and verifying the circular positioning, contouring, and performance evaluation of a CNC controller. A parameter adjustment method for the enhancement of CNC controller errors was also proposed. First, a mathematical representation of the error patterns was defined, and transformed into contouring forms. By comparing the measured data with the defined controller error patterns, an analysis method was developed based on the "weighted residual method". The algorithms developed in this study were implemented in a software for extracting the error patterns of an NC controller from the measured contouring data using a ball-bar. The software is also able to suggest the parameter adjustment required to enhance the NC controller performance optimally.