Knowledge-Based Simulation of a Glass Annealing Process: An AI Application in the Glass Industry

Abstract

This paper describes a knowledge-based simulation sys-tem for a glass annealing process. The long ovens, known as lehrs, in which annealing takes place are not well understood by their operators. In fact, only a few experts can predict the effects of a change in the lehr controls. Attempts to sim-ulate the behavior of the lehr using conventional methods have not been successful due to the size and complexity of the lehr. Our knowledge-based approach is capable of both simulating the glass temperature curve in an annealing lehr and planning the necessary lehr control settings to achieve a desired curve. It consists of two cooperating expert systems, one rule-based and the other frame-based. The system also includes a high-bandwidth graphics display which allows op-erators to interactively test control-setting changes and ask for the control settings which meet desired specifications. A description of the domain, a history of the development, and details of the design are all presented, along with lessons learned from the experience.