Expert system for blast furnace operation at Kimitsu works.

The experience and knowledge of operators are important for operation control of blast furnaces. A knowledge engineering or expert system that can represent this empirical knowledge was practically applied to Nos. 3 and 4 blast furnaces at Kimitsu Works, Nippon Steel Corp. In the development of the knowledge base for the expert system, the knowledge of the most experienced operators was represented by a hypothetical inference method composed of the sensor information judgement, interim judgement, final judgement and action stages. The expert system was implemented with emphasis placed on its maintainability by operators. Among the measures taken to this end are the adoption of a Japanese production language, augmentation of indication of inferred result, and installation of off-line terminals for modifying and test running the knowledge base. As a result of these efforts, the expert system can be largely operated and controlled by the field personnel. Since the expert system was brought on-line, periodic study meetings have been evaluating its performance and updating the knowledge base. The expert system is utilized in the actual operation control of the two blast furnaces at a high rate and the blast furnaces are stably operated.