| Verification of numerically controlled (N/C) machining programs prior to actual milling is often a very tedious and costly step in the manufacturing process. This dissertation describes an algorithm and its implementation in computer software which allows cost-effective checking of N/C milling programs for complex, sculptured surface parts. The current implementation is applicable to three-axis milling operations. The algorithm combines techniques originally developed for accurate, non-polygonal, surface shading and elements of B-rep solid modeling technology, to produce graphical output depicting the desired part as shaded surfaces with out-of-tolerance areas highlighted. Complexity analysis shows the algorithm to be of order N, where N is the cardinality of the tool path program. This result is compared with a direct solid modeling approach to the problem which has been shown to have complexity O(N('4)). |
