Now showing 1 - 10 of 163
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Nachhaltige Reinigung und Präparation

2024 , Uhlmann, Eckart , Polte, Julian , Burgdorf, Philipp , Reder, Waldemar

In der Fertigungstechnik lautet aktuell die Devise, innovative Wege für mehr Nachhaltigkeit zu entdecken. Für industrielle Reinigungsprozesse ist das CO2-Strahlen auf dem Vormarsch - im Beitrag wird beschrieben, warum.

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Edge Computing Software für den Zerspanungsprozess

2023 , Uhlmann, Eckart , Hocke, Toni , Heper, Martin , Polte, Mitchel

In aktuellen Forschungsprojekten entwickeln Forscher des Instituts für Werkzeugmaschinen und Fabrikbetrieb (IWF) Open-Source-Software für Edge Devices. Für die Auslegung der Fertigungsprozesse wird neben den ingenieurwissenschaftlichen Themen auch exemplarisch die Auslegung einer entwickelten Auswerteelektronik inklusive der Softwarebereitstellung adressiert. Der interdisziplinäre Ansatz, einschließlich der Softwarebereitstellung, wird exemplarisch an einem DFG-Projekt zur Prozessüberwachung bei der Ultrapräzisionsdrehbearbeitung diskutiert.

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Cooling Capacity of Oil-in-Water Emulsion under wet Machining Conditions

2023 , Nabbout, Kaissar , Sommerfeld, Martin , Barth, Enrico , Uhlmann, Eckart , Bock-Marbach, Benjamin , Kuhnert, Jörg

Many industrial machining operations are carried out under wet machining conditions. Modelling and simulating fluid-structure-interactions and conjugate heat transfer are still a challenge nowadays. In this paper, temperature dependent heat transfer coefficients (HTC) h(T) are experimentally estimated for wet machining-like conditions in a jet cooling experiment. The transient temperature is thereby used to solve an Inverse Heat Transfer Problem for HTC function estimation. Determined HTC are applied as input in related jet cooling simulation using the Finite-Pointset-Method (FPM) to validate the modeling approach. Additionally, wet cutting simulations numerically highlight the influence of determined HTC h(T) on turning.

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Automated defect detection of CT projection image data using Monte Carlo simulation

2022 , Uhlmann, Eckart , Hein, Christoph , Fehlhaber, Felix , Wang, Yifan , Dürre, Gregor

During the last decade industrial computed tomography has become one of the most important metrological procedures for internal inspection, where it sees widespread application in additive manufacturing. Evaluating the CT volume data for defects is currently a lengthy process involving data acquisition, reconstruction, surface reconstruction, and nominal/actual comparison. The goal of the presented project is the development of a new pipeline for automated defect detection operating solely with projection data. Using this pipeline, the amount of necessary projections NP and therefore the measurement time of each object will be heavily reduced. Reference projection data of non-defect objects were generated using a multi-GPU Monte Carlo X-ray simulation. The innovative implementation of the Monte Carlo simulation on GPUs makes the photon number of 5x1011required for a proper simulation of an X-ray projection feasible for the first time. This generated reference data was then compared to real data and the differences evaluated. With this new processing pipeline, it is now possible to achieve a defect analysis with less than six projection images, which decreases the minimum measurement time tmby nearly two magnitudes.

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Semi-automatic process control for efficient refurbishment of turbine blades

2023-06-16 , Uhlmann, Eckart , Polte, Julian , Mühlich, Christopher , Mönchinger, Stephan , Ebrahimi, Puya

The refurbishment of turbine blades requires the precise removal of damaged surface coatings. In manufacturing companies, this usually involves time-consuming activities such as detecting residual coatings and adapting process settings to varying turbine blade geometries. The use of automated systems therefore opens up opportunities to improve the efficiency of turbine blade refurbishment processes by replacing manual tasks. This paper presents an conceptual approach for a semi-automatic decoating process of turbine blades that integrates abrasive blasting technology into a closed loop process control system. The experimental setup consists of a robot for guiding the turbine blade in a blast machine and a nozzle system for local removal of residual coatings using abrasive material. Based on image processing the residual coatings of a turbine blade are labeled by a neural network and mapped to a 3D model of the turbine blade, which is used by a software control system to coordinate the decoating process. Using a prototype setup this paper investigates the applicability of the proposed approach and evaluates its feasibility.

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Enabling of Automatically Generation of Cutting Paths for Three-Dimensional Pre-Contouring with Waterjet Trimming

2023 , Reder, Waldemar , Uhlmann, Eckart

Abrasive Water Injector Jet Cutting (AWIJC) is a flexible machining process for manufacturing high-performance materials, such as titan-and nickel-base-alloys. Due to the low ductility and thermal conductivity of these materials, conventional machining is struggling with high tool costs and wear. The tool wear in AWIJC is independent of the machined material, and the process has the potential to provide a cost-efficient solution in machining high-performance materials. Trimming, a near-net-shape pre-contouring with multi-stage AWIJC, requires a detailed knowledge of cutting paths for all steps in advance. In order to enable a geometrical flexible manufacturing process, an automatically cutting path generation is necessary. This article presents an application developed with NX Open using Visual Basic. The application TrimCAD is able to provide all necessary geometries for trimming based on the geometries of initial and finished parts. Furthermore, it is possible to adjust the number of cuts and the degree of pre-contouring. All geometries are automatically exported as a standardized three-dimensional STEP-file. The STEP-geometries can be processed to the CAM-processor of the waterjet machine. TrimCAD is an innovative possibility to machine three-dimensional parts made of high-performance materials.

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Fundamental study on embedded displacement sensor arrays for ultrasonic-assisted ultraprecision machining

2022 , Uhlmann, Eckart , Polte, Mitchel , Bulla, Benjamin , Dambon, Olaf , Dicke, Clemens , Hocke, T. , Thißen, Kai , Heper, M.

Ultraprecision machining is a key technology for manufacturing complex steel moulds with dimensional accuracies in sub-micrometer range for mass production of optical components using micro-injection moulding. According to the state of the art, during the machining of carbide-forming metals, such as steel alloys, used single crystal diamond tools suffer from excessive tool wear. In order to overcome this technological und economical limitation, ultrasonic-assisted ultraprecision machining is applied successfully in a broad range of industrial and scientifically applications. Based on the reduction of the contact time between the tool and the workpiece excessive chemical and related tribological tool wear can be avoided. Nevertheless, the cutting speed is strictly limited to deceed critical contact times. Therefore, the monitoring of the tool vibration characteristic and thus the process control is a major challenge and of current industrial and scientifically interest. To overcome these challenges a method for in-situ measurement of the ultrasonic vibration is currently being developed and first results are shown. Using the sophisticated ultrasonic system, developed by SON-X GMBH, Aachen, Germany, up to a frequency fUS= 100 kHz the application of a dedicated eddy current sensor enabled the determination of the real path lines and the exact position of the cutting edge during the whole process with a displacement amplitude AD= 1 µm. The results were subsequently verified by laser vibrometer measurements. As a result of the investigation, an elliptical path movement of the cutting edge in the longitude direction AD,y= ± 1.0 µm and in z-direction AD,z= ± 0.34 µm could be determined using a frequency fUS= 100 kHz. Based on this new measurement method, the vibration characteristic can be specifically varied and adapted to the application. In addition, a comprehensive scientifical knowledge of the process can be gained and used to improve tool wear models.

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Echtzeit-Energieüberwachung in der Funkenerosion

2023 , Uhlmann, Eckart , Polte, Mitchel , Yabroudi, Sami , Thißen, Kai , Penske, Wilhelm

Ein großes Optimierungspotenzial der Funkenerosion liegt in den Energien der einzelnen Entladungen verborgen. Eine vektorielle Bestimmung der Entladedauern und die darauf basierende Energieberechnung sowie Klassifizierung erlauben es, die Entladeenergien, Entladungsarten und -dauern in Echtzeit zu überwachen und zu analysieren. Möglich wird dies durch ein Multiprocessing-Erzeuger-Verbraucher-Schema, welches überdies eine Visualisierung und Auswertung der Messdaten erlaubt.

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Smarte Überwachung elektrischer Großantriebe

2023 , Geisert, Claudio , Polte, Julian , Uhlmann, Eckart , Rauch, Hartmut , Brach, Karsten

Die Nutzung von Digitalisierungstechnologien im Kontext von Industrie 4.0 bietet insbesondere für den gesamten Bereich der Wartung und Instandhaltung von elektrischen Großantrieben großes Potenzial zur Schaffung innovativer Serviceangebote. Durch erweiterte Sensorik im elektrischen Antrieb und Intelligenz in der Verarbeitung und Analyse von Daten im Betrieb von Anlagen, kann eine vorausschauende Instandhaltungsstrategie eingeführt werden, die eine höhere Verfügbarkeit der Anlagen ermöglicht und gleichzeitig den Aufwand für Instandhaltungseinsätze reduziert. Um diese Potenziale im Servicegeschäft elektrischer Großantriebe zu erschließen, wird in diesem Beitrag ein hypothesengetriebener Ansatz zur Zustandsüberwachung beschrieben.

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Flexible Automatisierung mit Virtuellen Agenten

2022 , Uhlmann, Eckart , Polte, Julian , Mühlich, Christopher , Lindow, Kai

The process automation of hybrid assembly systems presents companies with the challenge of integrating people and machines into a collaborative system while taking socio-economic aspects into account. The transfer of biological principles to the design of production processes, in combination with Industry 4.0, enables the development of self-organizing systems. Inspired by this, a decentralized platform solution for flexible automation is presented in order to use human skills to increase productivity in a targeted manner.