This paper presents an approach to solving constraint satisfaction problems using Asynchronous Teams of autonomous agents (ATeams). The focus for the constraint satisfaction problem is derived from an effort to support spatial layout generation in a conceptual design framework. The constraint specification allows a high-level representation and manipulation of qualitative geometric information. We present a computational technique based on ATeams to instantiate solutions to the constraint satisfaction problem. The technique uses a search for a solution in numerical space. This permits us to handle both qualitative relationships and numerical constraints in a unified framework. We show that simple knowledge, about human spatial reasoning and about the nature of arithmetic operators can be hierarchically encapsulated and exploited efficiently in the search. An example illustrates the generality of the approach for conceptual design. We also present empirical studies that contrast the efficiency of ATeams with a search based on genetic algorithms. Based on these preliminary results, we argue that the ATeams approach elegantly handles arbitrary sets of constraints, is computationally efficient, and hence merits further investigation.

This paper presents a novel formulation of the configuration-design problem that achieves the benefits of the concurrent engineering (CE) design paradigm. In CE, all design concerns (manufacturability, testability, etc.) are applied to an evolving design throughout the design cycle. CE identifies conflicts early on, avoids costly redesign, and leads to better products. Our formulation is based on a distributed dynamic interval constraint-satisfaction problem (DDICSP) model. Persistent catalog agents map onto DDICSP variables and constraint agents map onto DDICSP constraints. These agents use a set of operations and heuristics to navigate the design space to eliminate sets of designs until a solution is found. Experimental results show that an architecture where each catalog agent resides on a separate computer has performance advantages over nondistributed approaches.

This paper describes decisions made during the development of an expert system for advising on problems that arise in the use of cutting fluids in engineering. It covers the problems of knowledge acquisition and of knowledge representation and of the relationship between them. The need for iterative prototyping is noted, and the choice between a database and a rule-based approach is discussed. The paper model and the machine model may not be isomorphic, although both are useful, albeit for different purposes.

This paper discusses the issues related to retrieval of cases in a case-based design system. The limitations of the conventional approaches are brought out, and this is followed by a description of a new approach to indexing and retrieval. This approach aims at capturing control knowledge required for retrieval from individual retrieval examples. Since this approach is based on past retrieval examples, we call it RBEX (Retrieval Based on EXamples). The proposed approach is implemented in a prototype system called CADREM. CADREM uses design methods used in solving past design problems to solve new problems. This is closer to the derivational analogy approach rather than the more common transformational analogy. CADREM has been tried in the domain of conceptual structural design of buildings. Sample outputs from CADREM are also included.

An ongoing research effort is consolidating material and process knowledge in a critiquing system dealing with fuzzy criteria to aid designers in evaluating the incorporation of composite materials into their design. The extent of knowledge required to perform the task of evaluating composite processes and materials is often beyond the expertise of many design engineers as they lack understanding of the nature of composite material manufacturing. The system under development is known as the Composites Design and Manufacturing Critiquing System (CDMCS). The CDMCS critiques a submitted design through interaction with the user. An account of the strengths and weaknesses of the design is supplied to the user through the facilities. The current focus of the system is on process selection, but the system is generic so that other aspects of composite material manufacturing may be included. The system is implemented in Macintosh™ Common LISP. This article describes the features of the system that have been implemented. The system is currently being extended to cover more than the primary process component of the domain.