A History-Oriented Envisioning Method

A novel and generic approach named as "history-oriented envisioning" is proposed to qualitatively envision all the possible and the sound situations focusing on our intended partial behaviors and actions of an objective system. Some basic notations called a "partial history" and a "partial situation" are introduced as the extensions of the conventional history and its situations representing qualitative, temporal behaviors and actions of the system. They provide the basic information of the intended partial behaviors and actions to the history-oriented envisioning. A major characteristic of the envisioning proposed here is its low complexity attained by the specified history of behaviors and actions in addition to the conventional scenario. Another important characteristic is its incremental structure enabling the iterative import of the predicted and/or observed information of the objective system. The feasibility of the proposed method is demonstrated by an example of controlling a steam generator of a plant. This method provides a basic measure to qualitatively estimate and plan system behaviors, and is considered to be applicable to wide engineering areas such as simulation, planning, design and diagnosis.