Alan H. Bond

A formal approach for product model information

A formal approach to the representation of engineering and CAD information is developed, called EDM. Its intended use includes defining schemas for integrated engineering databases, a normal form for translating between CAD systems and/or engineering applications, and for archiving. A set of information structures or forms is developed for describing engineering product models. The criteria identified and used to evaluate and justify the structures include: (1) representation of function, as well as the form and physical properties of the product; (2) support for multiple levels of abstraction and for the various phases of the product life cycle; (3) representation of semantics sufficient for all uses and for determining the validity of information used in applications; and (4) extensible semantics, supporting the addition of new functional evaluations, new technologies, and new conceptual generalizations. A small set of class structures and relations is presented. expressed as predicate logic forms, and composed from domains and aggregations. These class structures support: (1) functional descriptions of a product and their accumulation within multiple hierarchies, based on shared physical property descriptions; (2) the definition of physical objects in terms of functional descriptions and their composition into higher level objects; (3) generalizations of objects and functions; (4) constraint structures that specify integrity conditions; and (5) structures able to depict engineering technologies.

Cooperation in aircraft design

We describe how aircraft are designed in a large organization. We discuss the different phases of design and interaction with the customer. We then describe the models used by each specialist department and the interactions among departments during the design process. We observe that the main design choices are refinement operations on the design. We then briefly describe how the negotiation process is controlled by an organizationally agreed sequence of commitment steps. We then describe negotiation at higher levels in the organization. What decisions are made, the compromises worked out, and the effect of these higher-level commitments on the design process.We conclude that: (1) aircraft design proceeds by thecooperation ofspecialists (specialist teams or departments); (2) each specialist has its ownmodel of the design, and may use several different models or partial models for different purposes; (3) specialists have limited ability to understand each others models. They communicate using ashared vocabulary, but not necessarily shared technical knowledge; (4) design proceeds by successiverefinement of the models, which are coordinated and updated together; (5) the design decisions, which are acts of commitment and model refinement, arenegotiated by the specialists among themselves; (6) one way this negotiation process is organized and controlled is by the use ofcommitment steps; (7) negotiations occur at higher levels in the organization, resulting in commitments which greatly influence and constrain the design process and its organization, and which have the greatest effect on the cost of the product.

The cooperation of experts in engineering design

Abstract The cooperation of specialists with distributed knowledge is examined, in the context of knowledge-based support for collaboration among different engineering departments in carrying out large design tasks. It is concluded that 1 each specialist department has its own private justification language, but interacts with another department using a common shared language. 2 there may be little shared knowledge, and the shared language may involve an abstracted subset of the private languages of the collaborators. 3 collaborative reasoning can be limited because of • expression problems, not being able to ask the right questions. • rules of interaction and protocol, arising from legalistic procedures or from proof strategy. • performance problems, not having sufficient resources, due to the complexity of resolving the distribution. A simple model for collaborative reasoning is proposed that defines a collaboration strategy as a dialogue game.

A data model for design databases

This paper reviews the premises and current status of work on EDM, a data model for engineering product databases. A new data model is defined, and its application to the modeling of a portion of an intelligent CAD system demonstrated. Application of the data model to CAD database schema definition is discussed, as well as for translation between databases. This work summarizes and extends the previously published work on EDM, presented in (Eastman, Bond and Chase, 1991a) and (Eastman, Bond and Chase, 1991b).

Application and evaluation of an engineering data model

In a companion paper, we introduced an information model called EDM, for representing design and engineering information. EDM defines a small set of structures capable of depicting a wide range of semantics necessary for engineering design. These structures allow the definition of specific product models that are equivalent to database schemas, a fully instantiated structure is equivalent to an engineering or CAD database. EDM was developed in response to several criteria, among them the need to support changing technologies and evaluations and the need to support integrity checking. In this paper, EDM is applied to a small but complex example, a wall in building construction. Geometric, acoustic, and thermal properties are developed for the wall, defined in EDM structures. The example is then considered in terms of the evaluation criteria.

A subject-indexed bibliography of distributed artificial intelligence

An updated version of a large bibliography of articles and books related to distributed artificial intelligence (DAI) is presented. It is intended to be a complete and comprehensive list of research on DAI. It does not contain references to research on distributed computing, parallel processing for AI, connectionism, general AI, or research in social science disciplines that are important to DAI such as sociology, symbolic interactionism, or economics. >

Knowledge-based automatic dimensioning

Abstract A knowledge-based system, for automatically dimensioning a given 3D CAD model, is described. It was found that 1. 1. dimensioning should preferably be based upon manufacturing features which are sets of surfaces in specified 3d relationships 2. 2. several different kinds of rules are needed 2.1. (a) for each feature, rules for generation of dimensions onto sets of surfaces comprising it 2.2. (b) for each surface, the generation of linear dimension forms 2.3. (c) for each such form, the instantiation of the dimension onto an explicit 3d linear element 2.4. (d) the selection of 3d linear elements to express in 2d views, and the selection of views to use 2.5. (e) the layout of the 2d dimensions generated. 3. 3. a large amount of redundancy occurred, which had to be managed and retained, until final decision on selection and placement of 2D dimensions were made. The system works by a sequence of applications of rules, which construct a set of prioritized goals connected by a network of redundancy relationships. Rules of types (a), (b) and (c) are successively applied, starting with the 3D model, to produce linear dimensioning goals, with redundancy relations among them. View selection and 2D layout involve rules of types (d) and (e), and a complex evaluation of each individual 2D dimensioning choice for each 3D linear dimensioning goal. The system was written in Prolog, using the UCLA CADLOG intelligent CAD system.

Integrating Prolog and CADcAM to produce an intelligent CAD system

A discussion is presented of system issues in integrating an artificial intelligence system with a conventional computer‐aided design system. Two different schemes for integration, and experience in implementing a combined VM/PROLOG and CADAM, are described.

Distributed decision making in organizations

Problems and concepts for understanding how expert systems can be thought about, designed, and used in organized activity are discussed. Considerations and concepts from distributed artificial intelligence are explained, noting the connection with research in the computer support of organized activity. The authors recent research in two areas is outlined. They are cooperation in a vertical structure of an organizational hierarchy and horizontal cooperation among a team of agents with different specializations, solving a joint problem.<<ETX>>

Brain mechanisms for interleaving routine and creative action

We argue that frontal areas select and control routine action which originates in the basal ganglia, providing detailed interleaving with the creative knowledge elaboration activity of the cortex. The basal ganglia form loops and learn associations from various source areas to target areas of the cortex. We relate these connections to the cortical perception-action hierarchy. We outline examples of routinization and interleaving for the Tower of Hanoi problem, for routinization of motor control, of problem solving action, and of eye movement. We suggest a role for the ventral group of thalamic nuclei in controlling the flow of routine action.