Direct dimensional NC verification

Abstract A technique for automatic verification of three-axis numerically controlled (NC) milling programs is presented. Other methods proposed for NC verification rely on application of solid modelling technology. However, direct techniques suffer from heavy computational cost; and view-based techniques, while very efficient for simulation, are not capable of accurate dimensional NC verification. This article presents a unique approach to the problem based on direct comparison of the NC tool path program with a model of the desired part. An algorithm is presented that provides complete dimensional NC verification at a computational cost significantly less than direct solid modelling approaches. A software implementation of this algorithm produces graphical output depicting the desired part as shaded surfaces with out-of-tolerance areas highlighted. Several applications are presented that demonstrate verification of actual NC programs.