Model-based explanation of specifications for sequence control

Proposes a model-based approach to generating graphical explanations of high-level specifications for plant control. The specifications are explained by a symbolic simulator which generates a plant animation. The animation corresponds directly to images of a machine´s action which the designers have in their minds, so that the designers can easily confirm the accuracy of their specifications. Many kinds of knowledge about a plant are needed to generate the animation. This knowledge includes machine structures, machine actions, functions, materials, and so on. The knowledge about functions is the most important for the plant animation, as it allows the symbolic simulator to reason about operations on the materials. In particular, when a plant deals with solid materials, it is difficult to represent this knowledge because the machines used in such a plant usually have some functions which depend on the machines´ actions and plant conditions. To solve this problem, we have developed a framework to represent such functions and their relations