Steffen Ihlenfeldt

• Fraunhofer Institute for Machine Tools and Forming Technology

The application of robotics has evolved significantly through every industry. Robots do provide a wide range of motion, however their advantage of having lightweight components also limit the rigidity of the tool center point. Compensatory techniques involving joint stiffness determination and model-based predictions is one potential approach while...

The deep drawing tool development process, from method planning and design of tools to tool try-out and final commissioning, is very time-consuming and requires extensive iterative manual effort, particularly during the try-out stage. To accelerate the entire process, integrating obtained knowledge from the tool try-out stage into the early design...

The objective of this paper was to examine the potential for the automated release of research data within the context of material science consortium projects, with adherence to the stipulated rules and contractual agreements, while also considering all relevant framework conditions, including those pertaining to protection and confidentiality. The...

The tool try-out process of deep drawing tools is often tedious, iterative, and manual, leading to suboptimal results and prolonged ramp-up phases. Toolmakers first capture spotting patterns of the tool surfaces and then manually remove material based on these patterns. A key challenge is the complex interaction between the tools, the sheet metal,...

Die virtuelle Inbetriebnahme gewinnt zunehmend an Bedeutung, doch das Potenzial der Modelle für Optimierung und Wartung wird noch nicht ausgeschöpft. Der Beitrag beleuchtet die technische Umsetzung zur Nutzung der Modelle als digitale Schatten und zeigt praxisnahe Anwendungen. Herausforderungen wie die Integration realer Betriebsdaten unter Wahrung...

Human activity prediction in industrial environments with content semantics using 3D point clouds can ensure human safety and process efficiency. This work aims to train and optimize context-based AI models to develop a framework for anticipating human group activities and estimating human motion. Main Contributions of this work: 1. Design of multi...

In today's car body shop, the number of cases where multiple robots share workspaces is growing rapidly. This trend means more productivity—but it poses a challenge to program the increasingly complex robotic systems. We present a framework for automatically generating robot programs of multi-heavy-duty robot systems in car body manufacturing. The...

Human–robot collaboration (HRC) is an advancing field which integrates the skills of humans and robots for realizing more flexible and efficient production lines. However, one of the main challenges of HRC is ensuring human safety. This paper presents a new approach for 1. modeling the most common hazards mentioned in ISO 12100, 2. developing a mul...

The increasing digitalisation of machinery enhances production facilities by laying the foundations for advanced data analysis. To ensure effectiveness, it is essential that the collected data is of the highest quality for optimal use in various applications. The quality of data is subject to a variety of influences. This includes the design and op...

Zusammenfassung Ziel der strukturmodellbasierten Korrektur ist es, thermo-elastische Fehler an Werkzeugmaschinen steuerungsintegriert zu korrigieren. Sie wird in Abb. 1 anhand der thermo-elastischen Wirkungskette eingeordnet. Die strukturmodellbasierte Korrektur nutzt physikalisch basierte Modelle, das können z. B. Finite-Element-Modelle oder Knote...

Zusammenfassung Dieses Kapitel zeigt, wie realitätsnahe aufgaben- und maschinenspezifische Verluste prognostiziert werden können. Die Verlustprognosen können bereits in der Planungsphase zur Reduktion thermischer Schwankungen eingesetzt werden, wodurch geringe Verbesserungen des Temperaturganges möglich werden. Deutlich mehr Wert besteht jedoch in...

Zusammenfassung Am Beispiel der DMU 80 eVo von DMG Mori wird eine detaillierte Analyse des thermischen Verhaltens und der geeigneten Maßnahmen zu dessen Verbesserung gezeigt. Der Fokus liegt dabei auf in den vorangegangenen Abschnitten vorgestellten Verfahren, aber es wird an geeigneten Stellen auch auf alternative Ansätze verwiesen. Das Vorgehen e...

Zusammenfassung Die in Kap. 18 vorgestellte Methodik zum Betrieb von Kühlsystemen in Werkzeugmaschinen wird in diesem Kapitel exemplarisch am Beispiel eines Maschinengestells angewandt. Es wurde in der Vergangenheit die verformungsgerechte Temperierung von Gestellstrukturen aus Polymerbeton untersucht und dabei mehrere Einzelkreisläufe, die einzeln...

Machine learning has become increasingly important in materials design, yet traditional single-task learning (STL) models fail to fully exploit the potential of available data in scenarios involving multiple targets and incomplete datasets. While STL models overlook the inherent correlations between target properties, this study showcases how multi...

Additive manufacturing is gaining importance in a number of application areas, and there is an increased demand for mechanically resilient components. A way to improve the mechanical properties of parts made of thermoplastics is by using reinforcing material. The study demonstrates the development of a monitoring procedure for a fused filament fabr...

In sheet metal forming, the quality of a formed part is strongly influenced by the local lubrication conditions on the blank. Fluctuations in lubrication distribution can cause failures such as excessive thinning and cracks. Predicting these failures in real-time for the entire part is still a very challenging task. Machine learning (ML) based digi...

Modal analysis is a standard tool for evaluating the dynamic behaviour of machine tools. Since the dynamic behaviour can differ for operating and analysis conditions, the use of operational modal analysis for machine tools has been researched over the last decade. However, the operation of a machine tool is a special case with respect to the excita...

Sustainability and digitalization are of high importance for companies to stay competitive and cope with market requirements from internal and external stakeholders. Especially the current changes in reporting standards and frameworks increase pressure to quickly adapt internal processes and acquire the relevant data. In this context, Industry 4.0...

The rapid advancement of digitalization and AI presents significant opportunities for small and medium-sized enterprises (SMEs), particularly in manufacturing. However, adoption is often hindered by limited resources, expertise, and scalability issues. This paper introduces an interdisciplinary framework combining engineering, labor sciences, and b...

In engineering modeling, white-box and black-box concepts represent two fundamental approaches for modeling systems. White-box models rely on detailed prior knowledge of the physical system, enabling transparent and explainable representations. Black-box models, on the other hand, consist of opaque internal workings and decision-making processes th...

The responsible use of resources is an essential part of the manufacturing of industrial products. This includes the economical use of cooling lubricant and requires precise knowledge of the cooling mechanisms and their effect on the accuracy of the machine tool and thus the thermal error. A temporal and spatial resolution of the dynamic coolant fl...

Applying machine learning (ML) techniques in the context of limited data remains a challenge of practical importance. Questions on both the sufficiency of a given dataset for ML data analysis and data acquisition planning arise. Both aspects are quantitatively addressed in this work. The first one is treated as part of dataset diagnostics, which in...

The manufacturing industry must maintain high-quality standards while meeting customer demands for customization, reduced carbon footprint, and competitive pricing. To address these challenges, companies are constantly improving their production processes using quality management tools. A crucial aspect of this improvement is the root cause analysi...

Discovering optimal material designs in the design space can be significantly accelerated by leveraging machine learning (ML) models for screening candidates. However, the quality of these designs depends on the prediction accuracy of the ML models and the efficiency of the optimization algorithms used. This study comprehensively compares different...

Industrial anomaly detection models proved to be a viable solution for automating the task of visual inspection. Despite their effectiveness, the deployment of current deep learning models for anomaly detection for high-resolution images involves large memory requirements, which are unattainable in industrial deployments on edge devices. In this pa...

Nowadays, companies are operating in increasingly competitive and dynamic markets with rapidly changing customer demands. In order to meet these challenges, digitalization can be leveraged to achieve a transformation in product and service development. As a result, new concepts and methods are emerging, including smart product-service systems (smar...

Thermal error compensation via a numeric control (NC) system is a proven option for upgrading the precision of machine tools. The main advantage is the generally cost-effective application, as no changes to the machine design are necessary. Since modern machine tools are equipped with standard numeric controls along with additional functions and in...

Sensor-based monitoring of process and tool condition in milling is a key technology for improving productivity and workpiece quality, as well as enabling automation of machine tools. However, industrial implementation of such monitoring systems remains a difficult task, since they require high sensitivity and minimal impact on CNC machines and cut...

Thermal errors are among the most significant factors affecting the positioning accuracy of a machine tool. This paper demonstrates the advantages of combining reduced-order model (ROM) finite element method (FEM) simulations with data-driven error prediction algorithms, such as artificial neural networks (ANN) or characteristic diagrams. First, th...

Industrial robots are increasingly prevalent due to their large workspace and cost-effectiveness. However, their limited static and dynamic stiffness can lead to issues like mode coupling chatter and regenerative chatter in robotic milling processes, even at shallow cutting depths. These problems significantly impact performance, product quality, t...

Predicting the Remaining Useful Life of a machine components or systems is a pivotal technology in condition-based maintenance and essential for ensuring the reliability and safety in various production-engineering applications. The influx of extensive industrial data has notably enhanced the efficacy of data-driven Remaining Useful Life prediction...

This research responses to major challenges in the development and commissioning of multi-robot systems. A mechanical coupling through a handled workpiece may result in damage to the piece or the entire system when the distance between the robot TCPs deviates during motion. This paper introduces a novel method that allows to successively test and c...

This paper demonstrates the application of a fully automated machine learning (ML) pipeline on time series data from the domain of production engineering. The workflow aims to streamline the machine learning (ML) process and reduce manual effort by incorporating automated machine learning (AutoML) and automated featurization techniques. A comparati...

Additive manufacturing of plastic components in medical technology enables greater freedom of design when designing patient-specific products, in particular, in production of customised medical products, such as orthoses. In the present contribution, the advantages of a digital process chain are combined, from the 3D scan of the patient to CAD-supp...

Die Überwachung von Umformprozessen sowie des Maschinenverhaltens ist ein wesentlicher Enabler für gesteigerte Agilität und Effizienz in der Umformtechnik. Bei der Überwachung von Walzprozessen zur Herstellung von metallischen Bipolarplatten besteht die Anforderung einer genauen, sensitiven und kontinuierlichen Messung bei gleichzeitig mechanisch r...

Virtual prototyping is a strategic practice in the research and development of innovative products and machine tools. Virtual prototyping allows the integration of multidomain simulations into the designing process to replicate and analyze the impact of design choices on the overall system performance, reducing time-to-market while simultaneously i...

Zusammenfassung Strukturintegrierte Kraftsensorik besitzt zahlreiche Vorteile gegenüber klassischen Ansätzen zur Kraftmessung. Gleichzeitig wirken jedoch prozess- und strukturbedingte Einflüsse auf die Kraftsensoren, die in Abhängigkeit der Sensorposition durch ein Messmodell kompensiert werden müssen. Für dynamische Messungen während der Maschinen...

Zusammenfassung In jeder Phase des Produktlebenszyklus müssen unterschiedliche thermische Fragestellungen beantwortet werden. Zu diesem Zweck bildet der Digitale Zwilling die Maschine selbst und die auf ihr laufenden Prozesse aufgabenbezogen ab. Damit ist die virtuelle Maschine nicht ein einzelnes Modell, sondern muss als Digitaler Werkzeugkasten k...

Zusammenfassung Dieser Beitrag weist die Notwendigkeit der numerischen Abbildung von Prozess-Maschine Interaktionen in der Umformtechnik nach und stellt aktuelle Ansätze zu deren Modellierung und Berechnung vor. Dabei werden sowohl steigende Anforderungen hinsichtlich Modellkomplexität und -genauigkeit adressiert als auch auf die wachsenden Herausf...

Rising demands on manufacturing technologies lead to an increase in the complexity of corresponding machines and systems. This complexity acts as an obstacle to the development and realization of digital, usage-based business models for complex manufacturing systems. Particularly in the case of pay-per-use business models, it is necessary to monito...

The advancing digitization affects product design and manufacturing. Companies focus on product-service systems (PSS) to improve customer satisfaction and loyalty. However, these PSS become increasingly complex as digital technologies are incorporated and cross-company collaboration and manufacturing is facilitated. In essence, we can observe a tra...

Thermally induced position errors are one of the main error sources on the workpiece caused by the behavior of the machine tool. In today’s industrial environment, the correction of thermal errors is usually based on simple regression approaches, where the characteristic diagrams for correction are generated experimentally. The performance of these...

The deformation of press bolster plates under load can significantly impact the quality of manufactured workpieces. Consequently, press manufacturers are usually obliged to provide the metric proof of the permissible deformation values during the press commissioning process. Unfortunately, the existing measurement methods for determining bolster pl...

Multi-Material Jetting (MMJ) is an additive manufacturing process empowering the printing of ceramics and hard metals with the highest precision. Given great advantages, it also poses challenges in ensuring the repeatability of part quality due to an inherent broader choice of built strategies. The addition of advanced quality assurance methods can...

Implementing processes for traceability is required in various industries to assure product quality during manufacturing, provide evidence on required processing conditions or facilitate product recalls. Commonly, radio-frequency identification (RFID) or code recognition techniques (e.g. Data Matrix) are applied to track the flow of workpieces thro...

In recent years, space agencies, such as the National Aeronautics and Space Administration (NASA) and European Space Agency (ESA), have expanded their research activities in the field of manufacturing in space. These measures serve to reduce limitations and costs through fairing size, launch mass capabilities or logistic missions. The objective, in...

Energy consumption is an important factor in the operation of machine tools. Recent studies showed that in average, of the machine tools total energy demand is caused by internal cooling systems. The continually rising performance of machine tools, together with the importance of thermal stability, reasons the requirement for demand oriented coolin...

This study represents the first application of multifractal analysis to characterize spatial microforms’ volumes resulting from face milling on flat surfaces, emphasizing its novelty. Photographs of samples of C35 steel and AA22024 aluminum alloy, subjected to various cutting conditions during milling, were utilized to apply the multifractal approa...

Industrial robots have gained prominence due to their large work-space and cost-effectiveness. However, their limited static and dynamic compliance restricts their machining capabilities across various materials. Particularly, the inadequate dynamic stiffness of milling robots results in detrimental phenomena like mode coupling chatter and regenera...

Human-robot collaboration (HRC) is an advancing field which inte-grates the skills of humans and robots for realizing more flexible and efficient production lines. However, one of the main challenges of HRC is ensuring human safety. This paper presents a new approach for 1. modeling the most common hazards mentioned in ISO 12100, 2. developing a mu...

Die Fabrikplanung ist ein mehrdimensionales Aufgabengebiet und gegenwärtig mit dem Spannungsfeld aus Nachhaltigkeit, wirtschaftlicher Unsicherheit und kürzeren Technologiezyklen konfrontiert. Es werden kontinuierlich methodische Ansätze entwickelt und technologische Fortschritte in die Planungsprozesse integriert. Folglich entsteht der Eindruck, da...

The programming of industrial robots necessitates specialized expertise and significant time and effort, particularly for small batch sizes. However, with the increasing demand for agility in production, the solutions used for robot programming have evolved significantly. Intuitive robot programming systems based on diverse concepts have been intro...

The automated production of individualized products in a cyber-physical production system (CPPS) requires the combined automation of software and machine components. While this leads to increased productivity, the complexity of the CPPS may result in long unplanned downtimes when faults occur, and no system model is available to guide the maintenan...

Due to the high volatility of market demand and an increasing individualization, traditional textile manufacturing companies are required to carry out efficient production planning and scheduling (PPS). Highly complex manufacturing operations and a heterogeneous landscape of production equipment in terms of age, technology and automation level as w...

Manufacturing companies are operating in an environment that is becoming steadily more challenging and uncertain. The most serious risks in developed countries increasingly concern the shortage of skilled workers, growing competition from emerging countries, and ever-shorter development cycles for products that are expected to meet a growing variet...

The trend towards globalization is increasingly being questioned or put under the microscope for social, political, and economic policy reasons. Due to the closely net-worked trade relations unpredictable events like pandemics, natural disasters, technical disruptions of supply chains and political conflicts can have considerable economic and socia...

Data-driven methods, machine learning and artificial intelligence methods are not yet exploited to their intended potential in solving the technical-technological challenges, especially in industrial applications, despite versatile development progress. This is mainly justified by the insufficient practicality of AI solutions. To exploit the potent...

Energy consumption is an important factor in the operation of machine tools Recent studies showed that in average 1/5 of the machine tools total energy demand is caused by internal cooling systems. The continually rising performance of machine tools together with the importance of thermal stability, reasons the requirement for demand oriented cooli...

In recent years, space agencies like NASA and ESA have expanded their research activities in the field of Manufacturing in Space. These measures serve to reduce limitations and costs through fairing size, launch mass capabilities or logistic missions. The objective, in turn, is to develop technologies and processes that enable on-demand manufacturi...

Process monitoring in forming technology can serve as a basis for transparent manufacturing and closed-loop control systems. Particularly, sensor systems associated with tool clamping interfaces offer great potential for robust inline process monitoring but are hardly investigated. In this paper, a concept to monitor a sheet metal forming process c...

The hollow embossing rolling of thin-walled high precision components like metallic bipolar half plates is characterized by narrow process windows. Here, the knowledge of interaction between forming machine, roll and process is crucial for the process stability and quality of formed bipolar half plates. In this paper, the elastic machine and formin...

In-process monitoring in milling, specifically tool condition monitoring (TCM), is an important technology for improving productivity and workpiece quality. However, industrial implementation of in-process TCMs remains a difficult task, since progressing tool wear is indicated by small changes of various physical parameters. Therefore, a sensitive...

Awareness about climate change has led to policies and regulations but also customer preferences favoring sustainable production. Thus, producing businesses are confronted by this, as they consume a large share of resources. Therefore, when producing, additional dimensions beyond commercial feasibility ought to be considered. Here, literature on su...