DESIGN OF A RULE-BASED CONTINUOUS PROCESS CONTROLLER USING MODIFIED IDEF0 METHODOLOGY

This article proposes a new method to design a rule-based Continuous P rocess (CP) controller. This approach adopts Modified IDEF0 (MI) diagr ams as a graphical representation of production rules. Initially, the material flows or functional requirements for the CP are specified by synthesizing the MI diagram primitives. The control flows for the CP a re then created by a number of transformation rules. The MI diagrams a re therefore transformed to the Final MI (FMI) diagrams which can be d irectly transformed to production rules. The fact that production rule s are created by systematical transformation eliminates any redundant, contradictory, or unnecessary rules. The simulation approach can veri fy the consistency of the designed CP controller. Thus, a feasible rul e-based CP controller can be systematically developed. An illustrative gas transmission system is examined with three manufacturing policies , i.e. Proportional plus Integral plus Derivative (PID) control, Neura l control and Fuzzy control. The results indicate that all of these po licies are feasible in applying the proposed method. This method not o nly provides graphical representations to construct well-organized pro duction rules, but also includes a systematical transformation of the control flows for a CP controller.