FAPPS (Feature-based Automatic Process Planning System) is developed as a comprehensive metal cutting process planning system operated in PC environments. It can recognize the machining features automatically from a given 3D part design model, and then generates operation sheets, divided process drawings, NC codes, and inspection sheet. It consists of the following modules: tolerance input module for menu-driven input of tolerances, feature recognition module for automatic recognition of pre-defined machining features and compound features, process planning module for rule based determination of machining processes, divided process drawing module for automatic generation of divided process drawings, operation planning module for rule based generation of specific operation plans, and measurement planning module for automatic generation of CMM measurement plans.
The CMM measurement planning in FAPPS uses both geometric information and tolerance information from CAD files in order to determine measurement surfaces, number and positions of measurement points, and measurement sequences for inspecting machined parts. The measurement plan is represented in DMIS format for automated measurements using CMM’s. The measurement planning module that is realized in FAPPS is explained in this paper with the developed algorithms. Fuzzy logic calculation is used to determine the number of measurement points and geometric consideration for selecting measurement positions is performed.