Structured logic control in glass preparation processes

The development and operating procedures for process controls using modern control theory are compared with reasoning-based control formatted in structured logic. The discussion is based on recent results obtained on controls used in the preparation of molten glass for the manufacturing of glass articles. The general aspects of the temperature controller for a glass burner forehearth are presented. The limitations of using proportional-integral-derivative (PID) control in reducing upstream disturbances and the implementation of a feedforward-feedback algorithm based on a stochastic parameter identification method are discussed. Because of the sensitivity dependence of the stochastic algorithm on the operational variations of the forehearth, it is less favorable, given the current conditions prevalent in production plant floors. Preliminary results are presented for an application of fuzzy logic in the forehearth temperature process