A case-based NC code generating system for prismatic parts

This article describes a process planning system that utilizes case-based reasoning. The system, CBPlan, uses a feature-based part representation as a key to the case library. This representation is converted into queries that try to find a match in the case library, a match that points to the process plan. If the entire part does not have a match in the case library, the part structure is relaxed, and a process plan for the simpler part is sought. The system produces the final process plan from the partial plans retrieved for the relaxed parts. Since the cases in the library do not consider the exact dimensions of the part, the plans retrieved are modified to fit the dimensions of the particular part that is processed, and an NC program is then generated. Currently, the system is implemented using CLIPS embedded in a C++ environment, thus providing both declarative and object-oriented windows based programming environments.