モデルに基づく運転操作プランの生成機構を組み込んだプラント運転制御用エキスパートシステム

抄録

Conventional knowledge-based plant control systems control a plant according to heuristics stored in a knowledge base. So, it will fail if the plant falls in the situation not considered a priori by the designer of the plant control system. We call it an unforeseen situation. This paper proposes a new architecture that can dynamically generate a plan of plant operations against the unforeseen situation. This proposed architecture is based on the thinking process of a skilled human operator. It consists of three functions as follows : (a) the diagnosis of the unforeseen situation by using qualitative causal relations among plant process parameters ; (b) the plan generation of plant operations to recover the plant from the unforeseen situation by using the constraints satisfaction method ; (c) the plan verification by predicting a plant behavior when a plant is operated according to the generated plan. To realize these functions, the proposed architecture uses the multiple models, namely, a qualitative causal model, a device model, an operation principle model and a dynamics model. We have implemented a mode-based plant control expert system on the basis of this proposed architecture. This paper focuses on the plan generation and verification of plant operations and discusses the experimental results of this expert system.