Solid Model Approach to Numerical Control Emulation and Verification

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This project will provide a real-time verification of the input code for numerical control (NC) machine tools. The program will have several facets: visualization of the cutting process in wireframe, solid model display of the part after any desired interactive rendering of part geometry. The key aspect of this project -- solid modeling of the as-machined part -- is accomplished by a novel approach termed "extended octrees" (EO). In contrast to other popular solid model methods, the time per cut (Boolean operation) remains roughly constant with EO, as the part complexity grows. EO recursively subdivides the space occupied by the workpiece into cubic regions of variable size that are empty or filled (classical octrees) as well as face, edge and vertex cells. The model is fully three-dimensional with each cut input as a boundary representation of the volume swept out by the tool. Various improvements are proposed to reduce the time per cut (currently a few seconds per cut on a 386-based PC). The as- machined solid model can be compared with the computer aided design solid model (via a boolean) for automated verification. The solid model may also be helpful in assisting heuristic methods to carry out process planning for multi-axis NC code generation.