Process control method and system with employment of fuzzy inference

摘要

A process control method and a process control apparatus using a fuzzy control with reducing rules and membership functions. The process control apparatus for determining a manipulating variable of a controlled object, includes an input/output unit for inputting a present value of a controlled variable and for outputting the determined manipulating variable, a predicting unit having a simulator of a controlled object, for calculating a control variable after a predetermined time has passed, assuming now that a present value of the manipulating variable is continued, and a fuzzy controlling unit for inferring a manipulating variable at a present time by inputting a deviation value between a preset set-point value and a predicted value. The simulator simulates the controlled object as dead time and a first order delay. Since only the predicted value of the controlled variable is employed as the input of the fuzzy control, fuzzy inference can be simplified and noise resistance can be improved.