Jens P. Wulfsberg

Open production: scientific foundation for co-creative product realization

Globalization and the use of technology call for an adaptation of value creation strategies. As the potential for rationalization and achieving flexibility within companies is to the greatest possible extent exhausted, approaches to the corporate reorganization of value creation are becoming increasingly important. In this process, the spread and further development of information and communication technology often provide the basis for a reorganization of cross-company value nets and lead to a redistribution of roles and tasks between the actors involved in value creation. While cooperative, decentralized and self-organizing value creation processes are in fact being promoted, the associated potential for development and production engineering is being underestimated and hence not implemented sufficiently. This contribution will introduce a value creation taxonomy and then, using its notion and structure, describe the emerging transformations in value creation on the basis of case studies. Finally an adequate framework for analysing and configuring value creation will be presented.

Practical robot calibration with ROSY

The accuracy of pose of industrial robots is often unsatisfactory for advanced applications. Particularly regarding off-line programming, exchangeability and high precision tasks problems may occur which can be very time-consuming and costly to solve. Therefore a calibration system ROSY has been developed in order to increase the accuracy of standard robots and parallel-kinematic structures, like the Tricept robots.

Square Foot Manufacturing: a new production concept for micro manufacturing

Today a large number of microstructures are already employed as separate components or as constituents of larger modules in a broad spectrum of production in medical technology, optics, biotechnology, mechatronics, fluidics, (micro)-forming and tool construction. Current research activities are directed towards the downscaling of manufacturing procedures or the formation of complex process chains for the manufacture of micro workpieces. The Square Foot Manufacturing concept represents one approach aimed at achieving significant technical, economic and ecological developments in the production of microstructures by means of machining techniques that can be applied to a spectrum of materials as broad as possible. This fabrication concept representing a refinement of existing desktop manufacturing concepts is currently being developed at the Institute of Production Engineering of Helmut-Schmidt-University/University of the Federal Armed Forces Hamburg. This paper is intended to provide an overview of the theoretical concept and the current state of its technical implementation.

Human Hybrid Robot: a new concept for supporting manual assembly tasks

Due to the volatile conditions in today’s production, flexible assembly systems are required. However, current plants are often custom-made which are designed for a fix product spectrum. Especially for the assembly of unique products or products with a small-scale lot size and large-scale lot size with a high diversity of variants, many manufacturing steps are difficult or non economic to automate. Thus, a large part of the manufacturing processes is to be performed manually. These can be supported by assistance systems, but appropriate systems are seldom available. A new approach for supporting manual assembly tasks is the hybridization of biological and technical systems, a so-called “Human Hybrid Robot” (HHR). The kinematic chains of human, machines and tools are configured task-depended in serial and parallel arrangement. By doing so, the individual skills are used optimally. Main focus of this concept is improving the assembly accuracy and error prevention to boost the overall quality of the assembly processes. This paper presents the theoretical concept. Possible applications and realization of exemplary components are outlined to show the potential of HHR.

Square Foot Manufacturing—A Modular and Mutable Desktop Machine Tool System

This article presents the theoretical concept and the practical implementation of Square Foot Manufacturing (SFM). The concept meets the demands for micro manufacturing with modular, mutable, ad-hoc configurable, and function-integrated small machine tools. Here, a feed unit, a measuring system, a workpiece clamping device, and mechanical interfaces are described as components of the machine tool system to prove the feasibility and advantages of the SFM concept. The feed unit uses the principles of a monolithic flexure-based mechanism combined with piezo stack actuators. High precision is guaranteed by avoiding positioning errors and friction of conventional guidance systems. A low-force clamping device uses an elastic deflection of its chuck to securely fasten micro workpieces. It also acts as a workpiece carrier allowing for various production layouts. The mechanical interfaces are based on a kinematic coupling to provide high repeat position accuracy. The interface is necessary to obtain the SFM-typical high modularity and interchangeability of modules. Experimental measurements are shown to verify the performance of the components.

A novel methodology for the development of compliant mechanisms with application to feed units

This paper highlights the process of developing compliant mechanisms. Because of their high precision and the absence of friction compliant mechanisms are especially suitable for the use in micro manufacturing. In the following a systematic methodology of the development process is presented, including the design process, the realization of a mechanism and an application for feed units. At the first stage of design the topology of a compliant mechanism and the geometry of the flexure hinges are generated applying optimization methods. Afterwards efficient modeling strategies are applied to ensure dynamic models with high accuracy and manageable size for further investigations. Using these models an open-loop control is designed by means of mathematical trajectory optimization. At the final stage models and open-loop control are applied to design a closed-loop control completing the feed unit. This holistic approach reduces time and effort of the development process significantly. It supports the developer in creating reliable and innovative compliant mechanisms for a wide range of applications.

Modularity in small machine tools

Up to now, machine tools in micro production hardly feature modularity and hence offer only few opportunities to reconfigure or individualize a manufacturing process. This article gives a summary of concepts, how modularity in small micro machine tools can be designed and implemented. A size-adaptable machine frame is the basis for various possible process layouts. Adapters, a feed module with replaceable drive and kinematics, equipped with appropriate interfaces as well as a supply concept are introduced to allow further configuration. The combination of those concepts characterizes a small modular machine tool system. Technical solutions and fully functional prototypes will be shown and discussed in the following paper.

Hamburg Model of Knowledge Management

Knowledge management within manufacturing networks allows an efficient integration of distributed business processes in order to realise a common value creation. There are enormous potentials to accelerate the common innovation development or to cut costs through the harmonisation of cross-company value chains. Although the science and industrial community is aware of this, the potentials arising from a collaborative use of knowledge in networks have not been entirely exploited yet. The Hamburg Model offers a general guideline for developing a systematic management of knowledge within value creation networks, which is supplemented by a context-dependent, dynamic qualitative model that takes the relevant impact factors of a specific case of application into account.

Paradigm change: small machine tools for small workpieces

To overcome current limitations in micro manufacturing a new approach instead of evolutionary small step progress has to take place. Applying small machine tools to manufacture small workpieces allows for a leap of improvements enabled by the small size itself. This miniaturization in comparison to simply down-scaling current concepts qualifies the use of materials and technologies commonly not found in machine tools. This contribution describes the aspects, methodology, qualifications as well as cause and effects pursued by the approach of small machine tools for small workpieces.

Value creation in open-source hardware communities: Case study of Open Source Ecology

Technical progress in production technology, the advancement and spread of information and communication technologies (ICT) as well as the spill-over of the highly efficient and innovative open source principles to the world of physical products represent a new set of tools and concepts to address the challenges of sustainable economic development. Correspondingly, we can observe (new) modes of value creation that put into question traditional economic strategies and assumptions by stressing collaboration instead of competition and knowledge sharing instead of black box engineering. Open Source Ecology (OSE) is a famous example of a nonprofit organization which fosters worldwide participation and collaboration to jointly develop open source hardware for operation in both developing and industrialized countries. Based on the concepts open source appropriate technology (OSAT), the community aims at the free access to the knowledge and knowhow of low-cost and easy-to-build products to empower people to build and run a civilization. This case study describes and analyzes the value creation processes of OSE and derives new opportunities for business models based on openness.