Graphical simulation & automatic verification of NC machining programs

A machining simulator seeks to display graphically the effects on the workpiece (and associated fixtures) of the cutter motions prescribed in an NC program. Simulators enable NC programmers and machine operators to detect visually potential collisions and gross programming errors. A machining verifier seeks to determine automatically, without recourse to human judgement, whether an NC program will produce a specified part without undesirable side effects (collisions, cutter breakage, etc.). Simulators and verifiers both require solid modelling facilities, but simulators need only fast display generators for Boolean combinations whereas verifiers require more varied and powerful facilities. This paper summarizes the issues underlying simulation and verification while describing a new simulator that is being converted into a verifier.