N. Roth

A Key Issue in Product Life Cycle: Disassembly

Abstract Incoming environmental legislation is expected to impose recycling activities on industrial and consumer product manufacturers. Disassembly of used products is needed in order to make recycling economically viable in the current state of the art of reprocessing technology, thus avoiding the future high disposal costs. This paper gives an overview of disassembly research at universities, research centers and industrial companies, pointing out ongoing topics and trends for future activities. Among them, major attention has been paid to basic technological development, product design (design for disassembly), process design (selection of disassembly strategy and automation level) and system design (configuration of manual and automated disassembly facilities, design of disassembly tools). It is also shown how the emerging life cycle concept can be fully exploited to develop suitable ways of dealing with information related to environmental protection and resource optimization. A result of the survey is that further development on disassembly of existing products (technology, planning at process and system level) is needed to allow future products to be designed with recycling considerations in mind.

Assembly of microsystems

In the microworld, as well as in the macroworld, assembly is a crucial operation in the genesis of a product. This keynote paper focusses on the assembly problems occurring in the manufacturing cycle of microsystems. Scaling effects make that the assembly problems are different in the microworld. The different assembly operations and techniques, like manipulation by physical contact, non-contact manipulation, smart assembly techniques, and joining methods are thoroughly discussed. Finally, some relevant examples of micro-assembly systems and of assembled microproducts are given.

Relevance of Assembly in Global Manufacturing

Abstract Within the framework of entire production assembly plays an exceptional and specific role. In this step of the value adding chain the different components lead to the function determining unit. The globalization of the markets as well as technological innovations increasingly cause a redesign of the arrangement of the value adding chain in the global manufacturing network. Concerning the site selection for assembly plants two major strategies can be distinguished: Assembly follows the market and/or is shifted into regions of low labor costs. The global division of labor is supplementary favored because of new possibilities of telecommunications. A decentralized distribution of the assembly capacities can lead to productivity disadvantages due to the loss of economies of scale. This can in turn be compensated by local production alliances. State and specific problems of global networks in assembly will be analyzed in four relevant product areas.

Logistical Positioning in a Turbulent Environment

Abstract To describe the new challenges for manufacturing companies in Production Planning and Control (PPC), the term ‘turbulence’ is increasingly used. An analysis of the difficulties in PPC shows the similarities to phenomena known from physics. The aim of this article is to describe these phenomena qualitatively and quantitatively and to exploit the resulting findings for the design of PPC and the logistical positioning.

Application of Advanced Data Processing Technology for Integrated Inspection in Electrotechnical Assembly

Abstract The paper deals with integrated test and quality assurance systems for monitoring 3rd control of advanced production lines in electrotechnical industry The focus of the paper is on the application of innovative data processing technologies based on neural networks which are used both for acoustic signal interpretation as well as for rage processing By describing examples of their application in the manufacturing of electric motors and in the assembly of Printed Circuit Boards (PCB) both the technological approach as well as the conclusions from the industrial application are discussed.

Optimization of Set-up Strategies for Operating Automated SMT Assembly Lines

Abstract The state of the art in automation of the assembly of printed circuit boards (PCBs) is very advanced. But since the solutions realised up to low are mainly concentrated on the existing spectrum of standard components the introduction of the new technology of surface mounted devices (SMD) requires new approaches. The lead time for a defined production volume of PCBs with SME is decisively influenced by the choice of the set-up status of the assembly systems or assembly lines involved. The paper describes an approach to minimize the lead time by developing an optimization strategy for the initial set-up and subsequent changes in set-up of the components.

Knowledge of Selecting Assembly Cell Components and Its Distribution to CAD and an Expert System for Processing

During planning an assembly cell, either mechanized or manually driven, knowledge describing the necessities of assembly operations and the capabilities of the future equipment is essential. This domain is analyzed, structured and transformed in order to be processed by an appropriate software system. With this the devices are characterized and selected referring to the specific process demands derived from a product analysis. Geometrical and technological data are to be considered by available software (such as CAD) or specially developed modules. The extension of the CAD system in combination with an expert system improves the efficiency of the planning process as well as the reliability of its result.

Model Generation for Sensor-Guided Flexible Assembly Systems

Abstract Current research in sensor technology is leading to task- independent algorithms and knowledge- based processing systems. The paper emphasizes that in complex production processes, not only the geometric object descriptions but also the peripheral conditions such as cell- layout, surface properties, sensor interdependencies, and data integration must be considered. An adequate definition of the term ‘sensor model’ is given. By using AI- techniques, a generic knowledge- based machine vision system is designed that consists of four main elements: a declarative part, a generative element, a rule- based component, and an application dependent analysis program. The principles above are discussed in terms of two implemented 2D/3D- sensors. Finally an evaluation of prototype installations is given.

A Model-Based Grey-Scale Sensor System for Robotics

Summary Production devices for fabrication of medium and small aeries have to be flexible to meet the changing conditions of production. Scene- analysis systems for the recognition and inspection of workpieces are an important tool for flexible automation. Most vision systems currently available for robotics show severe limitations concerning recognition time, workpiece acquisition, illumination etc. This paper describes a Grey- Scale Sensor System for recognition of touching and overlapping workpieces, designed to meet the requirements of real applications in the factory. The system comprises 2 stages: a feature- extraction stage, which is designed mainly in special- purpose hardware and a model- based analysis stage realized in software. The system works with edge- based geometrical primitives and surface features. The model comprises topographical and procedural information in order to control the image- analysis, which is based on a Heuristic Search technique. A prototype version has been finished and interfaced to a robot. First experiences show that the system is working satisfactoryly in a wide range of environmental conditions and with different kinds of workpieces.

Clean Room Industrial Robot for Handling and Assembly in Semiconductor Industry

Abstract In many technical areas innovation is characterized by an increasingly progressing miniaturisation leading to a situation, that a growing spectrum of products has to be produced under clean room conditions. Technical as well as economic reasons are responsible for the necessity to automize large areas of that type of production, because even under protective measures human workers produce an unacceptable amount of pollution in clean rooms. Industrial robots can be used in clean rooms, but they have to be designed or at least to be largely modified to meet the requirements. In this paper development and technical features of such robot systems are described and results from an application in assembly tasks within semiconductor production are discussed.