Expert model for intelligent control of composite materials processing in a press

Abstract

An Expert Model for the in-process control of the press processing of thermoset composite materials has been developed. The knowledge base written using Texas Instruments Personal Consultant Plus (PC PLUS) expert system shell was interfaced with models written in FORTRAN (FORmula TRANslation). The expert model which is running on a single computer with a single processor takes advantage of the symbol crunching capability of the LISP (LISt Processing) computer language and the number crunching capability of FORTRAN. The Expert Model control system is a Qualitative-Quantitative Process Automation (QQPA) system since it includes both quantitative model-based and qualitative rule-based expert system operations. The feasibility of using models to determine the process state when sensors are not available or are malfunctioning was demonstrated. Hercules 3501-6/AS4 8″ × 8″ panels were processed in the heated-platens press using both the standard cure cycle and the expert model control system. Various physical and mechanical properties were measured from panels processed using the two cycles. Using QQPA, processing time has been reduced significantly without altering product quality.