János Nacsa

Application of software reuse and object-oriented methodologies for the modelling and control of manufacturing systems

In this paper object-oriented design and the application of software reuse of components of flexible manufacturing systems (FMS) will be introduced. The goal of this research is to provide methods and tools to build up FMS simulation models and control strategies easily, fast and reliably. As a software tool the SALMS reuse repository and its application will be demonstrated. The design methodology used for model development is based on the object-oriented Rational Rose CASE tool and on the use-case design of the OOSE methodology. A hybrid simulation and scheduling system (SSS) is used to validate and evaluate all results. SSS has been implemented as a combination of a traditional simulation/animation system (SIMAN/Cinema) and an intelligent expert environment (G2). The application of the real-time, intelligent G2 environment points to one of our R and D goals, to create intelligent, real-time control of FMS. Reuse in SIMAN/Cinema and in G2 will be analysed separately and together in general, and in the context of FMS.

Comparison of three different open architecture controllers

Abstract Since the late 80s there are a growing need of the machine tool builders and the end users to have open architecture controllers. Different levels of openness can be defined analyzing the available research results and products. The main initiatives leading the current research in these efforts are the European OSACA, the American OMAC and the OSEC from Japan. A complex comparison of these projects and their goals and achievements is presented in this paper. It is stated that in their present form it is not possible to merge easily the three results to get a unified and potentially worldwide accepted open architecture controller.

Application of artificial intelligence to problems in advanced manufacturing systems

Abstract Flexible manufacturing systems (FMS) are used worldwide for the production of parts in CIM systems. The design and operation of an FMS can be achieved only by the teamwork of several experts using different computer programs. Because of the complexity and diversity of the problems to be solved, traditional programming can be used only if combined with artificial intelligence techniques, such as expert and knowledge-based systems. This paper deals with the application of expert systems to assist in quality control and the simulation and control of FMSs. Well known traditional simulation (Cinema/SIMAN) and networking (MAP) packages are combined with high performance expert systems (ALL-EX, G2) to provide acceptable solutions. This paper reports on recent work where rapid prototype rograms are under test, with the ultimate goal of providing industrially applicable programs.

Integrated application of real-time expert systems for FMS evaluation and control

The paper describes some applications of expert systems (ES) for flexible manufacturing systems (FMS). A complex FMS simulation tool is shown with different connection possibilities to expert systems to have a good evaluation performance and the make steps toward automatic control. The interfacing problems of the software modules are also discussed. In the recent stage of the research rapid prototype programs are under test, and the future goal of CIM Research Laboratory (CIMLab) is to solve industrial problems with these tools and softwares.

Knowledge management support for machine tool designers using expert enablers

A set of methods and tools for the knowledge-based design (KBD) of machine tools is described. This paper presents a method to capture and formalize engineering knowledge and a set of software applications for ‘knowledge-based engineering’ (KBE), including product data management, design processes management, design documents management and automatic rule-based geometry generation. The aim of these tools is to solve the main problems that are facing machinery companies regarding design knowledge: the long learning process for new employees, loss of collective knowledge and experience, poor management of engineering knowledge and lack of agreed company standards and procedures for design.

Communication problems of expert systems in manufacturing environment

Abstract Recently increasingly artificial intelligent methods are used in the computer integrated manufacturing (CIM) applications. Real-time expert system shells are good tools to develop intelligent cell controllers. The first part of this paper summarises the communication problems of the expert systems in the CIM applications in the level of connection point of view. Then a research application called SSQA are shortly described with its aims and modules. The third part explains the way of the communication in SSQA.

Concurrent engineering approach to support CIM reference model-based FMS design

Abstract As a Computer Integrated Manufacturing system is a complex, expensive and long-term investment, it is necessary to have a good reference model as a first step to deal with its design and operation. A promising way to assist in CIM design and implementation is the Concurrent Engineering (CE) approach. This paper introduces a reference model (based on the CIM-OSA Architectural Framework) that was developed from a functional point of view. Details are given on how this model can be used for the concurrent design of products and Flexible Manufacturing Systems (FMS).

Intelligent Open CNC System Based on the Knowledge Server Concept

In an ideal scenario of intelligent machine tools (18) the human mechanist was almost replaced by the controller. During the last decade many efforts have been made to get closer to this ideal scenario, but the way of information processing within the CNC did not change too much. The paper summarises the requirements of an intelligent CNC evaluating the different research efforts done in this field using different artificial intelligence (AI) methods. In the second part of the paper a low cost concept for intelligent systems named Knowledge Server for Controllers (KSC) is introduced. It allows more devices to solve their intelligent processing needs using the same server that is capable to process intelligent data. In the final part this concept is used in an open CNC environment to build up an intelligent CNC. The preliminary results of the implementation are also introduced.

Some communication problems of KB-controlled manufacturing systems

Abstract Knowledge-based or intelligent control of flexible manufacturing systems (FMS) involves the continuous or frequent observation and evaluation of the status and condition of the system performance, decision-making based both on the evaluation results and on pre-defined knowledge, and then system operation according to these decisions. In the case of normal, scheduled operation, there is no need for either intelligence or interactions to modify the operation. The procedure given above may, however, help if any kind of disturbance or irregularity happens, as is rather common in the case of highly sophisticated, complex systems. This paper deals with control and communication problems inflexible manufacturing systems using programs based on a real-time expert-system environment, taking into consideration the requirement for openness in up-to-date systems. Two robot applications will be discussed as demonstrations.

Shop-floor communication with OSACA-compliant controllers

The ESPRIT framework within the EC had given a chance for a European consortium to develop a model for the new generation of open controls, that could be used for advanced manufacturing environment. The OSACA consortium (the name OSACA stands for: Open System Architecture for Controls within Automation Systems) had developed the methodology and the technology to build such open controllers. Within the 4th framework, the EC has launched a continuation project, named IDAS-OSACA, to help the dissemination process for the results achieved previously by the consortium. The article gives a summary on the external (superior and inferior) communication means applied with the OSACA controllers. The authors have prepared the article based on their review on the former OSACA project deliverables.