Yasuko Nakayama

Model-based automatic programming for plant control

A model-based automatic programming system for sequence control is described. The domain knowledge of the application area is discussed and an environment model that represents concepts of the domain-physical entities, actions and states, relations and conditions-in an extended semantic network is proposed. The system also has model-derivation methods. Because it uses a generic model to generate a specific description of the target plant, the system can be applied to the control of any plant of the same type. The model-based approach supports every task in the software life-cycle. As a result, it enables designers to specify control programs using natural terms and concepts. The system was evaluated by generating practical control programs for steel plants. It doubled design productivity while still producing programs that were satisfactory to design experts. These results suggest that at a primary goal of automatic programming research should be the development of models of the domain area.<<ETX>>

A knowledge representation for model-based high-level specification

A conditional semantic network as knowledge representation for model-based high-level specification in a plant control programming domain is proposed. In this representation, semantics of relations varies according to the plant situation, while it is determinate in conventional networks. A plant model enables designers to design control programs using natural terms and concepts of a plant. In order to interpret user-defined high-level specifications, the model includes knowledge about plant control in addition to plant components. The plant control knowledge is a type of constraint relation which exists among the plant components actions and states. It varies according to the plant situation. The plant model, including the plant control knowledge, is appropriately described in the conditional semantic network representation.<<ETX>>

An interactive specification acquisition method for software design

This paper describes a specification acquisition method used in PlantBASE, an automatic software design system for plant control. In this method, a plant model is first provided with the knowledge about behaviors and functions of each machine composing a target plant. By referring to this knowledge, PlantBASE recognizes the physical structure of the target plant from the specifications given in the form of tables and diagrams and generates a flowchart of machine operations, thereby reducing the cost of describing the control sequence for the plant.