Real-time verification of multiaxis NC programs with raster graphics

A system has been developed for verification of multiaxis NC programs with dynamic display of the in-process part in real-time. Such a system is needed because it is time-consuming and expensive to verify an NC program for machining a complicated part. Based on the concept of solid modeling, this system models a "machined" part by taking the Boolean difference of the tool swept volumes from the workpiece. Two key features contribute to the real-time performance of the system: an analytical method for computing swept volumes, and a scan-rendering algorithm for displaying images of solid models. Experience from implementing the system for industrial applications will be discussed. Also presented is a practical method for verifying NC programs with positional tolerances.