- 人工知能学会誌 (ISSN:09128085)
- vol.7, no.5, pp.877-887, 1992-09-01
This paper presents a computable design process model that is based on a logical framework. A computable design process model is useful not only to investigate designing activities but also to realize intelligent CAD (Computer-Aided-Design) systems. We propose a computable model based on a non-classical logical framework including abduction, circumscription, meta-level reasoning, and modal logic. First, we discuss design processes with a cognitive model of design processes. We point out four problems that are difficult to solve in the classical logical framework. Second, we formalize design processes in a non-classical logical framework. In this formalization, a design process is regarded as an iterative process of abduction, deduction, and circumscription. Abduction is used to obtain candidate descriptions of the design object, deduction to find out properties of the design object, and circumscription to solve inconsistency occurred in the design process. These types of inference are used for knowledge about objects ; on the other hand meta-level reasoning based on knowledge about action is used to reason out what should be done next. Furthermore we introduce data semantics to represent transitions of design states. Data semantics is a kind of modal logic which allows not only truth value t and f but also u (unknown), and a design process is interpreted as a process generating possible worlds sequentially. Then, we illustrate a design simulator based on this logical model. We discuss formalization and implementation of abductive inference and utilization of other inferences that are needed to implement a design simulator. We show that it can trace a design process in which design objects are gradually refined as the design proceeds.