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17th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2017

作者： Uhlmann, E. Reis, T. Oberschmidt, D. Rendel, O. Guhde, S. Fraunhofer Institute for Production Systems and Design Technology IPK Germany Institute for Machine Tools and Factory Management IWF Technische Universität Berlin Germany Universität Hamburg Department of Mathematics Germany

ISBN: (纸本)9780995775107

The coupling of real and virtual machine tool components in a hardware-in-the-loop environment is commonly used by state-of-the-art engineering tools as well as automated test procedures to verify the system behaviour. Time deterministic models are necessary to provide simulation results in a predictable time frame. This leads to efficient development procedures. This article presents a method and results of an automated engineering tool that uses time discrete deterministic order-reduced systems for the calculation of the dynamic machine tool behaviour. An innovative model-order-reduction (MOR) procedure was developed that provides a low-dimensional approximation of the original model with associated error estimation as well as inherent system characteristics, like passivity and steady-state accuracy, for a defined time step width. The validation of the calculation model, based on the new MOR procedure, was carried out on a three-axes test stand. It is representative for high dynamic machine tools and equipped with an integrated real-time control environment. The real-time settings as well as stiffness K, damping D, and mass M can be adjusted. Various low-dimensional time discrete models were implemented for demonstrative application and experimental validation of the MOR procedure. The results show high potential for the use in engineering processes. A reduction from a secondary order system with 19, 932 unknowns to a first order system with 80 unknowns was realized. Furthermore, the difference between calculated and measured deviation of the test stand's x-axes was achieved with a value of eXMax = 750 nm.

关键词： Couplings

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Machine Tool and technology for Manufacturing of Micro-structures by Micro Dry Electrical Discharge Milling

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Procedia CIRP 2018年 68卷 825-830页

作者： Eckart Uhlmann Ivan Perfilov Fraunhofer Institute for Production Systems and Design Technology Pascalstrasse 8-9 Berlin 10587 Germany Institute for Machine Tool and Factory Management Technische Universität Berlin Pascalstrasse 8-9 Berlin 10587 Germany

This paper presents a new machine tool concept for micro dry electrical discharge milling. It includes two different motion systems, EDM spindle and EDM generator, as well as the control system. The feed motion is realised with high-precision linear axes and the high-dynamic motion, needed for the gap width control, with a two axes piezo unit. A control system is based on the Open Source development platforms. It includes several microcontrollers, with each controlling individual subsystems of the machine. The hybrid EDM generator is based on the high speed GaN FET transistors, which allow to control charging and discharging phase of the capacitor without using resistance.

关键词： dry-EDM ED milling micro-structures

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Vision-based Identification Service for Remanufacturing Sorting

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Procedia Manufacturing 2018年 21卷 384-391页

作者： Marian Schlüter Carsten Niebuhr Jan Lehr Jörg Krüger Fraunhofer Institute for Production Systems and Design Technology Pascalstr. 8-9 10587 Berlin Germany TU Berlin - Department of Industrial Automation Pascalstr. 8-9 10587 Berlin Germany

One of the main goals of sustainability is to reduce the ecological footprint. As a result the automotive industry has been encouraged to become more efficient in using existing resources to reach a target value of at least of 85 % of a car’s weight for reuse and recycling as of 2015. The trade of used parts is expanding in total amount as well as in diversity of items. In industry practice employees have to decide upon the further use of a product based on experience or a reference list. We introduce a machine vision-based service for the identification of exchange parts. Images and weights of used parts serve as input whereby extracted inherent object features determine the identification of respective parts. First, in two main steps data is pre-filtered by its dimensions and volume out of a low-level 3D-model, created by a Shape-From-Silhouette algorithm. Secondly, a feature-based matching process is performed on the images. Two different feature matching approaches, a classic key point-based as well as a convolutional neural network, are evaluated. First results show the proof of concept recognition rates up to 96 %.

关键词： Remanufacuring Sorting Machine Vision Core Management Identification Object Recognition Reverse Logistics Closed-Loop Supply Chain Inherent Features

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A PSS maturity self-assessment tool

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Procedia CIRP 2018年 73卷 86-90页

作者： Konrad Exner Juliane Balder Rainer Stark Fraunhofer Institute for Production Systems and Design Technology Pascalstraße 8-9 10587 Berlin Germany Technische Universität Berlin Pascalstraße 8-9 10587 Berlin Germany

The ongoing discussion about digital transformation in combination with new digital services is increasing uncertainties in companies on how to proceed regarding their strategic development of new products, services as well as integrated offers. The main challenges for companies has been stated in several industrial workshops and projects. They comprise the assessment of the current situation, identifying the business value of digital transformation as well as the necessary capabilities needed regarding the implementation of a target vision. Based on the results of a literature analysis as well as initial prescriptive and descriptive study a revised PSS maturity model has been developed for assessing the status of a company reflecting on four dimensions: value proposition, business processes, customer and sustainability. The approach is complemented with an online self-assessment tool and generic action recommendations. The methodology has been applied and evaluated with a case company. The qualitative results indicate a good user acceptance and a very good ease of use as well as an improvable feedback regarding the action recommendations.

关键词： Product-Service systems maturity model self-assessment tool

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Investigating challenges of a sustainable use of marine mineral resources

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Procedia Manufacturing 2018年 21卷 321-328页

作者： Andrea Kaluza Kai Lindow Rainer Stark Technische Universität Berlin Industrial Information Technology PTZ 4 Pascalstraße 8-9 10587 Berlin Germany Fraunhofer-Institute Production Systems and Design Technology Pascalstr. 8-9 10587 Berlin Germany

High-tech products as well as renewable energy systems require ever-increasing quantities and more different metals. The extraction of metals and industrial minerals for the production of consumer goods and machines take place almost exclusively on land now. However, the interest in marine mineral resources has been re-inflamed due to the problem of geopolitical availability, such as fragile or failed raw material states and oligopolistic structures among the producers. This article gives a brief outline of the political, social and economic context of this change in interest in marine mineral raw materials extraction.

关键词： seabed activities marine mineral resources sustainability Post Paris Agenda multi-stakeholder processes technology

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Application of Micro Structured, Boron Doped CVD-diamond as μEDM Tool Electrodes

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Procedia CIRP 2018年 68卷 649-653页

作者： Eckart Uhlmann Dirk Oberschmidt Robert Bolz Fraunhofer Institute for Production Systems and Design Technology Pascalstrasse 8-9 Berlin 10587 Germany Institute for Machine Tool and Factory Management Technische Universität Berlin Pascalstrasse 8-9 Berlin 10587 Germany

High precision cavities are used for micro injection and micro embossing tools in the field of tool making and are mainly used for small batch or mass production of micro parts. In order to fabricate a large quantity of parts, wear resistant tool materials are required. In possession of a high hardness and a high Young's Modulus, such materials are often hard or even impossible to machine by conventional fabrication processes. Being independent of the work piece's mechanical properties, Micro-Electrical Discharge Machining (μEDM) is predestined for this case. μEDM is based on the modification of state of the art process technologies and universal machine tools applied for electrical discharge machining operations [1] , [2] . Besides the adjustment of the electrical parameters, the μEDM-process is also determined by the tool electrode's material which has a big influence on the material removal rate V W , the electrode's wear behavior, as well as the process results concerning surface quality and dimensional accuracy [3] . Experimental investigations aim at decreasing the wear of tool electrodes using novel electrode materials. To assure an efficient process, short production times and low tool wear ϑ are demanded. Therefore, electrodes with excellent electrical and thermal conductivity along with a high mechanical strength have to be used. Boron doped CVD-diamond is fulfilling these criteria. Microstructures within thin CVD-diamond foils are realized by direct structuring utilizing laser ablation and by indirect structuring using micro-structured copper substrates in the CVD-process, which transfer the micro-structure onto the growing diamond layer. Experiments were conducted in order to identify suitable EDM-parameters for different workpiece materials, namely steel 90MnCrV8, silicon carbide SiSiC and tungsten carbide K40F, which lead to lower tool wear ϑ and high accuracy.

关键词： μEDM die-sinking CVD-diamond tool electrode material

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Human robot collaboration - using kinect v2 for ISO/TS 15066 speed and separation monitoring

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Procedia CIRP 2018年 76卷 183-186页

作者： Martin J. Rosenstrauch Tessa J. Pannen Jörg Krüger Fraunhofer Institute for Production Systems and Design Technology Pascalstr 8-9 10587 Berlin Germany Technische Universität Berlin Institute for Machine Tools and Factory Management Pascalstr 8-9 10587 Berlin Germany

The use of industrial robots within assembly workstations where human and robot should be able to collaborate or even cooperate involve high safety requirements. One out of four possibilities outlined in the current technical specification ISO/TS 15066 for ensuring safety is speed and separation monitoring. Here the robot motion speed in- or decreases dynamically depending on the distance between operator and robot. This paper introduces an approach of a speed and separation monitoring system with the help of a time of flight sensing. After introducing this safety ensuring method, a Microsoft Kinect V2 is used to continuously detect human worker within a shared workspace. With the help of the robots joint angles from the robot control it is possible to compute the distances between all robot joints and the human worker. The shortest distance, which is at the same the critical distance time, is determined and as a consequence the velocity and acceleration values of the robot were set to safe values according to ISO/TS 15066. As it is not necessary to visually detect also the robot, but only human workers, this approach is very resilient. Afterwards the introduced setup is tested by a real detected human in front of a Kinect and a simulated industrial robot (Universal Robot UR5) in the robot operating system ROS. Measurements show that depending on the position of the worker the robots speed adapts to recommended safety values up to a complete halt if necessary. Conclusively all results are discussed and an outlook for possible fields of applications is given.

关键词： human robot collaboration safety ISO/TS 15066 kinect v2

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Application of Additive Manufactured Tungsten Carbide Tool Electrodes in EDM

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Procedia CIRP 2018年 68卷 86-90页

作者： Eckart Uhlmann André Bergmann Robert Bolz Witalij Gridin Fraunhofer Institute for Production Systems and Design Technology Pascalstrasse 8-9 Berlin 10587 Germany Institute for Machine Tool and Factory Management Technische Universität Berlin Pascalstrasse 8-9 Berlin 10587 Germany

Application fields of electrical discharge machining (EDM) are limited due to given process conditions. When producing structures of high aspect ratios or using multi-axis machining, removed particles assemble at the machining zone, leading to process instabilities. A promising approach to improve EDM process conditions is the utilization of flushing channels in the tool electrode. However, with increasing complexity of the electrode geometry and the local integration of the mentioned flushing channels, conventional electrode manufacturing reaches its limitations. By applying Selective Laser Melting (SLM), these limitations are eliminated. The appropriate integration of flushing channels, even for complicated electrode geometries, improves process conditions during EDM in a variety of applications, leading to a higher material removal rate V W and reduced tool wear ϑ compared to machining without flushing. Additionally, the number of required tool electrodes can be reduced, as SLM enables an efficient integration and miniaturization of all features in a single electrode. Of particular interest in the field of EDM is carbide. Because of its wear resistance and stability, it is an ideal electrode material, which is commonly applied in μEDM. Tungsten carbide-cobalt is representative for this group of materials, which is already used in tool manufacturing. Several tests show a general suitability of carbide tool electrodes made by SLM for EDM-processing. However, the SLM process parameters and the composition of the carbide-cobalt show significant impact to the EDM results. A lower proportion of cobalt leads to reduced material removal rates V W and rising tool wear.

关键词： EDM die-sinking SLM additive manufacturing tungsten carbide

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Affordance Based Approach to Automatic Program Generation for Industrial Robots in Manufacturing

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Procedia CIRP 2018年 76卷 133-137页

作者： Oliver Heimann Jörg Krüger Fraunhofer Institute for Production Systems and Design Technology Pascalstr 8-9 10587 Berlin Germany Technische Universität Berlin Institute for Machine Tools and Factory Management Pascalstr 8-9 10587 Berlin Germany

Due to the increasing demand for flexible and low-cost production, manufacturing solutions involving human robot interaction have become much sought-after. Robotic manufacturers meet the demand with a rising number of low cost robots specifically designed around safety and usability. However, the programming is still based on a tool centric teach-in. This paper discusses an affordance based approach for process programming in industrial manufacturing. Using low level feature detection and a consecutive evaluation, a fast programming method for industrial applications is presented. The paper presents the concept and a prototypic implementation for a welding process. Using the affordance detection, the system is able to identify relevant seams based on an image of the work space. The identified seams are then presented to the user for review with the means of augmented reality. Lastly, the system derives a welding program based on the detected seams. First experiments show promising results concerning programming speed and path accuracy for different work piece shapes and task definitions. Finally, based on the experience gained with the prototype, the outlook discusses the possibilities and further fields for future work.

关键词： Robot Welding Programming

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Precision enhancement technologies for multi-axis ultra precision machining of freeform optical elements with variable micro/nano structures

Precision enhancement technologies for multi-axis ultra prec...

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ASPEN/ASPE 2017 Spring Topical Meeting on Manufacture and Metrology of Structured and Freeform Surfaces for Functional Applications

作者： Uhlmann, E. Kühne, S. Jagodzinski, M. Widemann, R. Haskic, K. Institute for Machine Tools Factory Management IWF Technische Universität Berlin Berlin Germany Fraunhofer Institute for Production Systems and Design Technology IPK Berlin Germany LT ULTRA-PRECISION TECHNOLOGY GmbH Herdwangen-Schönach Germany

Aspherical and freeform optics receive uprising attention, due to their advantages in terms of aberrations and reduction of system volume, for example in spectroscopic applications. An additional surface structuring e... 详细信息

ISBN: (纸本)9781510853546

关键词： Enhancement Technologies Optical Component precision machining aberrations MULTIAXIAL surface structure reduction Precision

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