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Software-Defined Manufacturing (SDM) is a new paradigm for how to manufacture in the Industry 4.0 factory of the future. The approach requires a fundamental change in thinking and reinvention of central business models in production technology. This paper discusses the main challenges on the way to a software-defined factory of the future and illustrates possible solutions. An exemplary future factory is presented, in which the validation of the solutions is carried out. For this purpose, cloud-based Computerized Numerical Control (CNC) is considered as use case. Experimental results demonstrate the proof of concept and show the potential for further applications.

Industrial machine tool feed drives are predominantly controlled by cascade control due to their low tuning complexity and inherent robustness. However, the cascaded structure requires the inner cascades to have higher dynamics than the outer cascades, which limits the achievable dynamic accuracy. Direct control approaches, which substitute the position and velocity cascade, offer the potential to utilize the unused potential. A promising approach is model predictive control (MPC), which optimizes the manipulated variable with a plant model along a prediction horizon. However, model uncertainties between the nominal model and the real plant lead to tracking errors. Therefore, this paper presents, a linear MPC (LMPC) and an adaptive MPC (AMPC) with an additional integral action to robustly compensate for model mismatches. Both controllers use a compliant model, are real-time capable with a sample rate of $${{2}\,\textrm{kHz}}$$ 2 kHz and consider state and input space constraints. The AMPC accounts for position-varying stiffness and friction. The controllers are experimentally compared with classical P-PI cascaded control on a ball screw drive. They show a tracking error reduction of $${{37}{\,\%}}$$ 37 % (LMPC) and $${{44}{\,\%}}$$ 44 % (AMPC) during a high speed motion profile and an increase in bandwidth of $${{180}{\,\%}}$$ 180 % (LMPC) and $${{184}{\,\%}}$$ 184 % (AMPC), resulting in significantly improved dynamic accuracy.

Dieser Beitrag präsentiert ein Konzept für den simulationsgestützten Betrieb von Flugrobotern im dynamischen Produktionsumfeld einer wandlungsfähigen Fabrik. Zentrale Bedeutung wird dabei dem digitalen Zwilling beigemessen, der ein Umgebungsmodell inklusive Realdatenanbindung bereitstellt. Darauf basierend können Dienste implementiert werden, die den Betrieb eines Flugroboters unterstützen, beispielsweise zur Lokalisierung, Bahnplanung oder Mensch-Flugroboter-Interaktion. This paper presents an approach for the simulation-based operation of flight robots in the dynamic production environment of a flexible factory. An important role is assigned to the digital twin, which provides an environment model including real data connection. Based on this, services can be implemented supporting the operation of a flight robot, e.g. for localization, path planning or human-robot interaction.

Um wettbewerbsfähig zu bleiben, streben Unternehmen eine effiziente, fehlerfreie Produktion an. Neben der End-of-Line-Qualitätskontrolle mit anschließender Nacharbeit, bestehen Ansätze, um Prozessparameter entlang des Materialflusses für eine Fehlerkompensation anzupassen. In einer software-definierten Fertigung nimmt dieser Planungsraum durch Enabler der Industrie 4.0 weiter zu. Dieser Beitrag zeigt eine Konzeption für die iterative Planung der Fertigungsprozesse, um das vollständige Potenzial des Produktionssystems für die Produktion individueller fehlerfreier Produkte zu nutzen. To remain competitive, companies strive for efficient, defect-free production. In addition to end-of-line quality control with subsequent rework, there are approaches to adjust process parameters along the material flow for error compensation. In software-defined manufacturing, this planning space increases further due to enablers of Industry 4.0. This paper presents a scheme for iterative planning of manufacturing processes to exploit the full potential of a production system for manufacturing individual defect-free products.

Dieser Beitrag stellt ein Konzept für die Integration von interaktiven Simulationsmodellen in einer Virtual-Reality (VR)-Simulationsumgebung vor. Dabei werden die Simulationsmodelle aus der virtuellen Inbetriebnahme (VIBN) von Produktionsanlagen betrachtet. Ein Ziel der erweiterten VIBN mithilfe von einer VR besteht darin, die Lücke zwischen VIBN und der realen Inbetriebnahme zu schließen. Damit das vorhandene VIBN-Modell möglichst einfach in der VR-Visualisierung integriert werden kann, ist es essenziell, eine Durchgängigkeit des Simulationsmodells im Engineering zu gewährleisten. Aus diesem Grund wird auf das bestehende Austauschdatenformat „AutomationML“ eingegangen. This paper presents a method for integrating interactive simulation models into a virtual reality (VR) simulation environment. To this end, simulation models from virtual commissioning (VIBN) of production plants are considered. One goal of enhanced VIBN using VR is to close the gap between VIBN and real commissioning. To integrate the existing VIBN model as easily as possible into the VR visualization, it is essential to ensure engineering continuity for the simulation model. For this reason, the existing exchange data format AutomationML will be discussed.

Die Vorspannung ist eine zentrale Größe für Kugelgewindetriebe, da sie Umkehrspiel und Nachgiebigkeit minimiert, gleichzeitig jedoch die Reibung und den Verschleiß erhöht. Die Vorspannungsnachstellung an Kugelgewindetrieben bietet die Möglichkeit, Verschleißerscheinungen zu minimieren und die Lebensdauer bei gleichbleibendem Betriebsverhalten zu erhöhen. In diesem Beitrag werden passive, rein mechanische Konzepte zur belastungsgerechten Vorspannungsnachstellung vorgestellt, die gegenüber bestehenden Lösungsansätzen vorteilhaft hinsichtlich der Kosten und des Integrationsaufwandes sind. The preload is a key factor for ballscrew drives, as it minimizes backlash and compliance while increasing friction and thus wear. Preload adjustment on ballscrews allows for minimizing wear and increasing service life while maintaining the same operating behavior. This article presents purely mechanical methods for load-compliant preload adjustment, which are advantageous compared to existing solution approaches in terms of cost and integration effort.

Software-defined manufacturing (SDM) überträgt den Ansatz der Trennung von Anwendungen und unterlagerten Systemen, welcher ein entscheidendes Paradigma und Erfolgsfaktor für die Digitalisierung in vielen Branchen ist, auf die industrielle Produktion. Neben einer gesteigerten Integration von IT und OT können so die Produktionsprozesse einer gesamten Fabrik dynamisch durch Software anpasst werden. Ziel dieses Beitrags ist es, den SDM-Ansatz und die zur Umsetzung notwendigen Konzepte hinsichtlich technologischer Infrastruktur und Abstraktionsschicht vorzustellen. Anhand von zwei Use Cases werden die sich daraus ergebenden Potenziale aufgezeigt. Software-defined manufacturing (SDM) takes the approach of separating applications from underlying systems to industrial production. This paradigm has been the key success factor for digitization in many sectors. Thus, the production processes of a factory can be dynamically adapted by software. This paper aims to present the SDM approach as well as the required measures for its implementation with respect to technological infrastructure and abstraction layer. Two use cases demonstrate the opportunities of SDM.

Load-oriented lightweight structures are commonly designed based on topology optimization. For machine tool parts, they enable the reduction of moving masses and therefore increase the resource and energy efficiency of production systems. However, this usually results in complex part structures that are difficult or impossible to produce using conventional manufacturing methods. In this paper, a hybrid layer laminated manufacturing (LLM) method is proposed enabling manufacturing of topology-optimized machine tool parts. The method is referred to as hybrid, as the subtractive structuring of metal sheets is combined with the additive joining of the sheets by adhesive bonding. This enables enclosed inner cavities without support structures, which are used to approximate the optimal density distribution from a topology optimization via manufacturing. The proposed LLM method is validated on the basis of a bearing block of a ball screw feed drive. A experimental study in the time and frequency domain on a test rig confirms the principle suitability of the LLM method for the production of industrial applicable lightweight components., Deutsche Forschungsgemeinschaft, Projekt DEAL

A distributed simulation makes it possible to couple simulation tools and lays the foundation for the usage of multicore capabilities to decrease the calculation time. In consequence the simulation is partitioned on multiple simulation tasks. If simulation tasks with different integration step sizes are used, the configuration is called multi-rate simulation. In real-time simulations the tasks are calculated parallely, which means that fast tasks do not wait for the simulation result of slower tasks. A sequential approach where fast tasks wait for slower tasks would slow down the overall simulation and therefore tear the real-time requirements. In a real-time multi-rate approach, signal processing of the coupling signals between the tasks is required. For this signal processing, multi-rate methods are used. Easy multi-rate methods lead to stepped signals in the faster task, because the slower task does not provide a new calculated signal at each timestep of the faster task. In this work further methods are investigated in an industrial real-time simulation environment. The analysis contains continuous and discontinuous as well as energy conserving methods. It is shown how these different methods perform for various kinds of signals. The methods are compared and evaluated on signals with different characteristics, which allows a recommendation for the choice of a method in a specific simulation scenario. The application of the multi-rate methods is shown on an example virtual commissioning simulation of an industrial robot. It shows that the right choice of a multi-rate method has a big impact on the overall simulation result.

Von Industrierobotern wird zunehmend eine hohe Bahn genauigkeit und ein gutes Störunterdrückungsverhalten gefordert. Um dem gerecht zu werden, wird hier ein semiaktiver Dämpfungsansatz vorgestellt, der Antriebsstrangschwingungen aktorbasiert dämpft. Damit geht ein stärker gedämpftes Systemverhalten einher, wodurch sich die Regelverstärkungsfaktoren erhöhen lassen. Das Resultat ist ein verbessertes Gesamtverhalten, das an einem „Kr210–2“ von Kuka mit semiaktiver Dämpfung an Achse 1 nachgewiesen wird. Industrial robots are increasingly required to provide high path accuracy and good disturbance rejection behavior. In order to achieve this, a semi-active damping approach is presented, which damps drive train vibrations actuator-based. This leads to a more damped system behavior, allowing control gains to be increased. The result is an improved overall behavior, which is demonstrated on a Kuka Kr210–2 with semi-active damping on axis 1.

In multi-axis processes, such as welding or 3D printing, the determination of the orientation of the tool relative to the workpiece is usually determined by technology-dependent geometric algorithms. In the simplest case, the orientation of the tool is defined according to the surface normal vectors of the workpiece surfaces. However, with large curvature gradients, this method can lead to jumps in the orientation which lead to unwanted stopping of the translational motion. In the linear interpolation of this movement, the path speed usually decreases significantly due to the relatively large compensating movement of a kinematic system. This type of path movement usually has negative effects on the CNC process, which requires constant path velocities. This paper describes a method for time-optimized path planning that utilizes the orientation tolerances of multi-axis processes. Orientation tolerances are process-dependent tolerances that indicate which orientation ranges (angular positions) from tool to workpiece are permissible without decreasing the process quality. The potential time savings of this method are shown with an extreme example of a planar 3-axis kinematics and on an industrial 7-axis CNC system.

Der Impulsaktor bietet einen Ansatz, durch mechanische Stöße die Dynamik von Vorschubachsen deutlich zu erhöhen und nahezu sprunghafte Geschwindigkeitsänderungen zu erlauben. In diesem Beitrag wird vorgestellt, wie ein Versuchsstand mit zwei Vorschubantrieben, der bereits einen zusätzlichen Aktor besitzt, um einen Aktor in der zweiten Achse erweitert und die Bahnplanung mit zwei Aktoren angepasst wird. Ein Nachweis der Funktionalität erfolgt simulativ an einem Mehrkörpermodell. The impact-based actuator is an approach to significantly increase the dynamics of feed axes by means of mechanical impacts, enabling almost abrupt velocity changes. This paper presents a test stand with two feed drives and one additional actuator is being extended by another actuator in the second axis and shows how path planning is adapted to operation with two actuators. A verification of the functionality is done simulatively on a multi-body model.

Zahnstange-Ritzel-Antriebe werden überwiegend bei großen Werkzeugmaschinen eingesetzt und häufig mit indirekter Lageregelung betrieben. Hieraus resultiert eine geringe Positioniergenauigkeit und ein unzureichendes dynamisches Nachgiebigkeitsverhalten. Um den hohen Genauigkeitsanforderungen moderner Werkzeugmaschinen gerecht zu werden, wird in diesem Beitrag eine beschleunigungsbasierte Störgrößenkompensation vorgestellt. Experimentelle Ergebnisse belegen eine Verbesserung des Störverhaltens. Rack-and-pinion drives are mainly used in large machine tools and controlled by indirect position control. This leads to low positioning accuracy as well as an insufficient dynamic compliance. To meet the high accuracy requirements of modern machine tools, this paper presents an acceleration-based disturbance compensation. Experimental results prove a considerable improvement of the disturbance behavior.

The term co-design describes a collaborative design process, usually across the boundaries of individual areas. A major aspect, and often an obstacle in the implementation of the co-design approach, is the establishment of a centralized data management system. In the past, the data management concept has been approached from different perspectives. Current approaches usually are oriented along the process chain and thus reflect a unidirectional flow of information. Neither the information feedback nor the reaction to adjustments in upstream model steps is supported, which makes continuous collaboration more difficult and at best reduces the co-design approach for continuous data usage. This paper addresses these weaknesses while outlining an integrative data processing concept enabling co-design between the domains of construction and industrial prefabrication. Geometrical information generated during architectural design and construction planning is reused for the production of components, manufacturing-related design adjustments are transferred back into the domain of construction. Changes throughout the entire process are centrally recorded. To ensure independence from the software tools used and to consider their great diversity, data exchange is largely based on standards, namely industry foundation classes and the standard for the exchange of product model data. In order to counteract the sequential processing according to a waterfall model and to support the co-design approach, the industrial prefabrication toolchain, consisting of computer-aided manufacturing software and downstream postprocessors, is largely automated, so that reprocessing of a workpiece for minor geometric adjustments no longer requires any interaction of the production planner.

Additive manufacturing is becoming increasingly important for industrial applications. Especially laser powder bed fusion processes play a decisive role. However, the technology often lacks in reliability and part quality due to complex process interactions and disturbing influences. To counteract these limitations, a flexible and high-dynamic control of relevant process parameters, taking into account the transient process conditions, is indispensable. Currently, the most process parameters are often kept constant, since the used control systems do not offer real-time capable interfaces for intervention. To enable the adjustment of parameters during the process, an open control architecture for galvanometer scanners and laser sources was developed. The architecture is based on an industrial control system in combination with a field-programmable gate array (FPGA) communicating via a real-time fieldbus. The novel control architecture is used to integrate a model-based feedforward control, adjusting the laser power, scan speed and scan strategy based on the current powder bed temperature calculated by a two-dimensional thermal model during run time. An integrated learning algorithm autonomously tunes the process parameters during the manufacturing process and determines the optimal combination of laser power, scan speed and powder bed temperature to achieve a homogeneous melt pool. On average, the standard deviation of the powder bed temperature along the scan path was reduced by 48% for the simulated test cases.

Fehler bei der Inbetriebnahme von Maschinen und Anlagen sind kostspielig und zeitintensiv. Dabei steigen die Kosten mit dem Voranschreiten des Entwicklungsprozesses stark an. Um Missverständnisse oder Planungsfehler zu minimieren, bevor diese hohe Kosten verursachen, wird ein intelligentes Assistenzsystem beschrieben, das die Vorstellungen, Ziele und Mittel des Kunden auf einfache Weise erfasst und auftretende Probleme oder Unklarheiten reaktiv korrigiert. Der Maschinen- und Anlagenhersteller profitiert dabei von einer automatisch erstellten, einheitlichen Dokumentation der Kundenanforderungen. Errors during commissioning of machines and plants are costly and time intensive. The costs grow higher with every step of the development process. To minimize misunderstandings and planning errors during the requirements phase, an intelligent assistance system is being introduced which acquires the ideas, goals and resources of a customer in a simple manner and reactively corrects arising problems or ambiguities. The machine and plant manufacturer profits from the uniform documentation of customer requirements.

State of the art machine tool controllers offer several Internet-of-Things (IoT) interfaces for machine data acquisition using industrial or edge computers. However, the available data exchange rates for these communication platforms are limited to a few hundred Hertz. As the data is not available in high frequency resolution, such a network communication is not suitable for monitoring and optimizing highly dynamic machining processes. This paper describes an efficient system architecture, which enables the acquisition of internal machine data as well as the high frequency sampling of external sensors. Based on this data, an Operational Modal Analysis (OMA) approach can be used to determine the tool tip dynamics during the machining process. Identification of tool tip frequency response requires the reconstruction of the excitation of the machine tool structure, i.e. the occurring machining forces. For this purpose, an approach relying on monitoring the commanded motor currents is applied.

Zunehmend suchen Komponentenhersteller nach Lösungen zur Bereitstellung von digitalen Abbildern ihrer realen Komponenten. Ziel ist es, dass Kunden damit ihre Automatisierungskonzepte virtuell validieren und Steuerungssysteme im Entwicklungsprozess anhand einer virtuellen Inbetriebnahme eingehend testen und optimieren können. Simulationswerkzeuge für die virtuelleInbetriebnahme bieten mittlerweile vielfältige Schnittstellen zur Einbindung bestehender Teilmodelle bei der Modellierung eines digitalen Zwillings einer Maschine oder Anlage. In diesem Beitrag wird die Online-Plattform „TwinStore“ für den Austausch von Simulationsmodellen zur virtuellen Inbetriebnahme vorgestellt.

In diesem Artikel wird ein hybrider Ansatz mit Aktor vorgestellt, der die Impulsübertragung bei mechanischen Stößen ausnutzt, um eine Vorschubachse sprungartig zu beschleunigen. Der Maschinentisch wird hierfür mit einem Aktor ausgestattet, der eine Impulsmasse relativ zum Tisch bewegt und zum geforderten Zeitpunkt definiert auf eine vorgesehene Stoßfläche schlägt. DasErgebnis ist, dass mit diesem Konzept beispielsweise Ecken einer Kontur mit annähernd konstanter Bahngeschwindigkeit durchfahren werden können, da nahezu keine Beschleunigungs- und Bremswege notwendig sind. Experimentelle Untersuchungenerfolgen an einem einachsigen Versuchsstand, zusätzlich dazu wurde ein Simulationsmodell entwickelt, mit dem das Potenzial für einen mehrachsigen Betrieb abgeschätzt werden kann.

Der Einsatz wandlungsfähiger Plug-and-Produce-Systeme (PnP-Systeme) [1 - 4] für Montageaufgaben ermöglicht eine gesteigerte Reaktionsfähigkeit auf schwankende Losgrößen und sich ändernde Produktvarianten, die aus stets wechselnden Kundenbedarfen resultieren. Neue Montageprozesse können je nach Anpassungsbedarf mit modularen, vernetzten Systemmodulen ohne signifikanten Engineering-Aufwand integriert werden [1]. Sicherheitstechnisch stellt diese hohe Wandlungsfähigkeit allerdingseine große Herausforderung dar, da bei jeder ungeplanten Systemveränderung eine erneute Risikobeurteilung nach der Maschinenrichtlinie [8] sowie eine Aktualisierung der Dokumentation nach der Betriebssicherheitsverordnung (BetrSichV) [9] erforderlich ist. Dies führt zu einem erhöhten personellen wie auch monetären Aufwand während der sicherheitstechnischen Abnahme. Dieser Beitrag stellt ein neuartiges Konzept AutoSafety für eine assistierte Risikobeurteilung basierend auf einer Softwarelösung vor.

The objective of this letter is to propose a drive-based control method for damping joint vibrations in order to improve the machining quality and the productivity of robot machining. The machining quality is significantly determined by the transfer behavior of the gearboxes installed in the robot joints. This letter presents a novel approach for drive-based damping of these vibrations and thus for increasing the dynamic path accuracy on the basis of secondary encoders. The approach represents an enhancement of the independent joint control, which is widely used in industry. The simulation as well as the experimental results on a KUKA KR210-2 demonstrate the effectiveness of the presented control method for damping gearbox vibrations and increasing the dynamic path accuracy of industrial robot manipulators.

The great flexibility provided by generative manufacturing offers immense potential for the structural component optimization. However, this freedom needs to be utilized by appropriate CAx tools. In this paper, we present a novel slicing method, enabling the automatic generation of topology-optimized Laminated Layer Manufacturing (LLM) parts. With this method a part of arbitrary shape can be automatically sliced and equipped with a uniform virtual grid that is suitable for manufacturing. The optimal density distribution is then mapped onto the individual slices and locally approximated through the introduction of variably shaped cavities. By using 3D modeling techniques all LLM sheets are modeled parametrically and assembled automatically. To verify the functionality of the presented method, it is applied to two practical parts and compared with a conventional topology optimization method.

A hardware-in-the-loop simulation has to use the control cycle as simulation clock. This time-deterministic clocking can be difficult to meet for complex behavior models in a real-time simulation. To accelerate a real-time simulation, the calculation can be parallelized by co-simulation whereby multiple, differently detailed behavior models can be simulated parallelly. In these multi-scale models, a slower, detailed model guides a fast, abstract model. In this work, a Kalman filter is examined as a multi-rate method to predict the signals of a physical-based model for a material flow simulation in real-time. To improve the results, smoothing and boundary conditions are added.

Der Einsatz von Industrierobotern erlaubt auch kleineren Betrieben die Automatisierung verschiedener Bearbeitungsschritte. Daraus resultierende Möglichkeiten für die flexible Kleinserienfertigung stellen jedoch gleichzeitig große Anforderungen an die Werkstückaufspannung. Dieser Beitrag stellt ein Konzept für eine vollautomatische Werkstückfixierung vor, welche die Bearbeitung von großflächigen Schalenelementen aus leicht zerspanbaren Werkstoffen durch Umpositionieren von Vakuumgreifern während der spanenden Bearbeitung ermöglicht. The use of industrial robots enables small-sized enterprises to automate various processing steps. The possibilities for flexible small series production result in great demands being placed on workpiece clamping. A concept for fully automatic workpiece fixturing is presented to enable the manufacturing of large-area shell elements that are made of easily machinable material by dynamic repositioning of vacuum grippers during machining.

Bin picking describes a robot system that picks unsorted objects from a bin based on sensor data. The object recognition is one of the main difficulties when calculating the grasping pose. In the worst case, a faulty object recognition leads to a system standstill. This work introduces a framework concept for improving the object recognition by predicting the configuration of all the objects in the bin based on an initial scan in form of a point cloud. This is done by taking advantage of an online simulation, with the goal of reducing the total number of scan cycles, which leads to a reduced risk of failure and improves the overall performance of a bin picking system.

Bei mehrstufigen Produktionssystemen rotierender Bauteile kann bereits ein kleiner Fehler zu Ausschuss führen. Um die Wettbewerbsfähigkeit europäischer Unternehmen zu gewährleisten, wird eine Null-Fehler Fertigung angestrebt. In diesem Beitrag wird dafür eine Web-App vorgestellt, die Bauteilvari- ationen automatisch erkennen und Fehlerkompensations- strategien ableiten kann. Das Potenzial des mehrstufigen Produktionssystems wird genutzt, um Fehler am Bauteil im Produktionsfluss durch eine geeignete Steuerung und Regelung zu beheben. In multi-stage manufacturing systems of rotating parts, even a small defect can lead to rejects. In order to maintain competitiveness, European companies aim for zero-defect manufacturing. We present a web app that can automatically detect part variations and derive defect compensation strategies. The potential of the multi-stage production system is used to eliminate part defects downstream by means of suitable control.

Industrieroboter werden zunehmend für Anwendungen eingesetzt, in denen es wichtig ist, die programmierte Bahn exakt einzuhalten. Hierfür ist vorwiegend das dynamische Verhalten der Roboterachsen entscheidend. Stetig steigende Anforderungen an die dynamische Bahngenauigkeit motivieren die Analyse und Quantifizierung der Achsdynamik. In diesem Beitrag wird ein neuer Ansatz vorgestellt, bei dem das dynamische Verhalten von Roboterachsen mithilfe von Secondary Encodern ermittelt wird. Industrial robots are increasingly used for applications with high requirements on path accuracy. The main factor here is the dynamic behavior of the robot joints. To satisfy rising demands on dynamic path accuracy, it is essential to analyze and quantify the axis dynamics. This paper presents a novel approach to determine the dynamic behavior of robot axes using secondary encoders.

Direct-deposition Additive Manufacturing technologies like Fused Deposition Modeling suffer from several drawbacks such as anisotropic mechanical properties which impair part quality. Multi-Axis Additive Manufacturing (MAAM) promises to significantly reduce these drawbacks. However, path-planning for the complex kinematics still poses a problem which has only been solved partly and for very specific applications. This paper proposes a software architecture for a general purpose path-planning tool for MAAM technologies enabling the simultaneous implementation of different strategies. The architecture is designed to be extensible, largely machine independent and enables granular multi-scale optimizations. First implementation results and illustrating examples demonstrate the modularity and extensibility.