Christoph Klauck

ARC-TEC : acquisition, representation and compilation of technical knowledge

A global description of an expert system shell for the domain of mechanical engineering is presented. The ARC-TEC project constitutes an AI approach to realize the CIM idea. Along with conceptual solutions, it provides a continuous sequence of software tools for the acquisition, representation and compilation of technical knowledge. The shell combines the KADS knowledge-acquisition methodology, the KL-ONE representation theory and the WAM compilation technology. For its evaluation a prototypical expert system for production planning is developed. A central part of the system is a knowledge base formalizing the relevant aspects of common sense in mechanical engineering. Thus, ARC-TEC is less general than the CYC project but broader than specific expert systems for planning or diagnosis.

FEAT-REP : representing features in CAD/CAM

When CAD/CAM experts view a workpiece, they perceive it in terms of their own expertise. These terms, called features, which are build upon a syntax (geometry) and a semantic (e.g. skeletal plans in manufacturing or functional relations in design), provide an abstraction mechanism to facilitate the creation, manufacturing and analysis of workpieces. Our goal is to enable experts to represent their own feature-language via a feature-grammar in the computer to build feature-based systems e.g. CAPP systems. The application of formal language terminology to the feature definitions facilitates the use of well-known formal language methods in conjunction with our flexible knowledge representation formalism FEAT-REP which will be presented in this paper.

Formal business process engineering based on graph grammars

Abstract Designing and managing a companys specific landscape and its business processes has been identified as a great challenge for several years. Business processes are highly dynamic and distributed and can only rarely be planned, modeled and analyzed completely. For a computer-aided business process system, which supports the designing and managing process, first of all a powerful uniform formalism is necessary, where all necessary knowledge concerning companys and its processes can be represented. In this paper we will concentrate on the introduction of such a formal methodology to describe business processes, company organization structures and information technology structures in one uniform formalism. The ideas we use are mainly based on methods from graph grammars, process management, Artificial Intelligence and business process (re)engineering.

PIM—skeletal plan-based CAPP

Abstract In order to create a production plan from product model data, a human expert thinks in a special terminology with respect to the given workpiece and its production plan. He identifies certain areas of interest, the so-called application features. The exact form of these features is influenced by his manufacturing environment (e.g. available tools) and by his personal experience. The expert associates the application features with fragments of a production plan. By combining these fragments, bearing in mind some general principles, he creates the complete production plan. We present a set of representation formalisms which allow to model this approach very closely. Based on a general geometrical/technological representation formalism, an experts personal terminology is described in terms of features. Skeletal plans (abstracted plans or fragments of plans) are associated to these features. The generation of a production plan consequently boils down to a sequence of abstraction, selection and refinement: The geometrical/technological representation of a workpiece allows the recognition of the relevant features. The associated skeletal plans are selected, merged and refined until a complete plan is created. This is demonstrated in the CAPP system PIM (Planning In Manufacturing), which has been developed as a prototype.

Content-based image retrieval

In order to retrieve images it is much more sophisticated and usual for human beings to use natural language concepts, e.g. mountainlake, than syntactical features, e.g. red region left up. This leads to a content-based image retrieval. Furthermore, it is unreasonable for any human being to make the content description for 1000 of images manually.From this point of view, the project IRIS1 (Image Retrieval for Information Systems) combines well-known methods and techniques in computer vision and AI in a new way to generate content descriptions of images in a textual form automatically. The text retrieval is done by IBM SearchManager for AIX.The system is implemented on IBM2 RISC Sytem/60003 using AIX4. It has already been tested with 1200 images.

STEP : Überblick über eine zukünftige Schnittstelle zum Produktdatenaustausch

STEP (Standard for the Exchange of Product Model Data) ist ein von der ISO entwickeltes Standardformat zur Abbildung produktdefinierender Daten (ISO TC 184/SC 4, NAM 96.4) im Gesamtkomplex der CIM-Techniken (Computer Integrated Manufacturing), der 1993 weltweiter Standard werden soll. In diesem Bericht wird ein Uberblick uber den derzeitigen Entwicklungsstand von STEP gegeben. Dabei werden die bereits weitgehend stabilen Teile detailliert beschrieben.

Skeletal Plans Reuse: A Restricted Conceptual Graph Approach

In order to reuse the existing skeletal plans in the manufacturing process planning system PIM, in this paper, we propose a plan reuse framework, in which Restricted Conceptual Graphs are used as the internal representations of these skeletal plans and reusing these skeletal plans is approached by retrieving the most specific general candidate and effectively modifying.

Akquisition und Repräsentation von technischem Wissen für Planungsaufgaben im Bereich der Fertigungstechnik

Im Bereich der Fertigungstechnik kann eine Fulle von Planungsaufgaben identifiziert werden, die fur eine Bearbeitung mit Methoden der KI geeignet erscheinen. Das Projekt ARC-TEC am DFKI wendet die KADS-Methode zur systematischen Entwicklung von Expertensystemen an und erstellt Tools fur alle Phasen dieser Entwicklung. Die Brauchbarkeit der entwickelten Methoden und Tools wird am Beispiel der Erstellung von Arbeitsplanen fur die Drehbearbeitung demonstriert. Besonderes Augenmerk gilt dabei der expliziten Reprasentation des konkreten Expertenwissens und der Bearbeitung des gegebenen Problems in einer der Vorgehensweise des Experten moglichst naheliegenden Weise. In the area of production engineering many planning tasks can be found which seem well-suited to be tackled using AI-methodologies. The ARC-TEC project of the DFKI uses the model based KADS approach for a systematic development of expert systems and provides tools to support the different phases of this development. The generation of work plans for manufacturing by turning is used as an example to demonstrate the applicability of the different tools and methodologies. Special focus is upon the explicit representation of the concrete experts knowledge and the problem solving strategy which closely follows the way an expert solves the problem.

Graph Grammar Based Object Recognition for Image Retrieval

In order to retrieve a set of intended images from an image archive, human beings think of special contents with respect to the searched scene. The necessity of a semantics-based retrieval leads to a content-based analysis and retrieval of images. From this point of view, our project Image Retrieval for Information Systems (IRIS) develops and combines methods and techniques of computer vision and knowledge representation in a new way in order to automatically generate textual content descriptions of images. IRIS retrieves the images using a conventional text retrieval system.

Heuristic classification for automated CAPP

In order to create a process plan from a workpiece description, a human expert thinks in a special terminology with respect to the given workpiece. The steps of human thinking during the generation process of a process plan are following the principles of heuristic classification: First using feature recognition an abstraction process is realized yielding a high level (qualitative) description of the current workpiece in terms of features. To these features certain (more or less) abstract (partial) process plans -- the so-called skeletal plans -- are associated. In the refinement step these skeletal plans are merged together to one complete process plan. In this paper we present a set of domain-oriented higher level representation formalisms for features and skeletal plans suitable for the modeling of this approach. When an experts (process planners knowledge has been represented using these formalisms, the generation of a process plan can be achieved by heuristic classification. This is demonstrated in the CAPP- system PIM, which is currently implemented as a prototype.