A FUZZY EXPERT-SYSTEM FOR THE DESIGN OF MACHINING OPERATIONS

In this paper, a fuzzy expert system called Smart Assistant to Machini st, or SAM, is introduced. The system consists of four modules: a data base, a cutter selection module, a cutting condition design module and a learning module. The database consists of four data files: work mat erial data file, machine tool data file, machining plan data file (whi ch defines desirable material removal rate, surface finish, cutting sp eed, feed, depth of cut, etc.) and cutter data file. The cutter select ion module is developed based on fuzzy logic, in which the cutter sele ction is conducted in three steps. First, the input information is ''f uzzyized''. Next, using the fuzzy correlation functions, cutter grades and cutters are selected. Then, the selected grades and cutters are s earched against the cutter data file to check the availability. The cu tting condition design module is developed based on fuzzy non-linear p rogramming and user interactive graphics; The learning module is devel oped so that users can fine-tune the fuzzy functions to further improv e the performance of the system. The system has two distinct features: (1) it can select cutters and design cutting conditions based on part ial and imprecise information, and (2) it selects commercial cutter pr oducts used on shop floors. The use of the system is demonstrated usin g two examples.