Fraunhofer-Institut für Optronik, Systemtechnik und Bildauswertung IOSB

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  • Publication
    Learning Petri net models from sensor data of conveying systems based on the merging of prefix and postfix trees
    ( 2022)
    Windmann, Stefan
    Petri nets are a common modeling approach for parallel processes such as transport operations in conveying systems. In industrial applications, the Petri net models are usually created manually, which involves a lot of effort, especially if the modeled systems change frequently. This paper introduces a new learning method to automatically generate Petri nets from sensor data acquired in conveying systems. The underlying approach is to create prefix and postfix trees of possible event sequences and to merge them into a compact graph, which can be transformed into a deterministic Petri net model of the conveying system. Experimental results show that the proposed method produces realistic Petri net models even for conveying systems with ambiguous events.
  • Publication
    Migrationskonzept zur Einführung von Ethernet TSN in die Feldebene
    ( 2021)
    Schriegel, Sebastian
    ;
    Jasperneite, Jürgen
    Anwendungen, wie z. B. eine datengetriebene Prozessüberwachung oder eine für die Fertigung kundenindividueller Produkte notwendige wandlungsfähige Produktionstechnik, erzeugen neue und zusätzliche Anforderungen an die Industrielle Kommunikation. Die Kommunikation muss stoßfrei rekonfiguriert werden können, um Plug-and-Play-Dienste zu ermöglichen und so skalierbar und sicher sein, dass eine vertikale Kommunikation vom Sensor bis zur Cloud möglich wird. Als Basis für ein skalierbares Kommunikationsnetzwerk, welches von verschiedenen echtzeitfähigen oder nicht-echtzeitfähigen Protokollen konvergent genutzt werden kann und so die bisher harte Grenze zwischen IT und Feldebene durchlässig macht, soll Ethernet TSN verwendet werden. Um auch einfache Sensoren ohne Gateways anzuschließen, sollen neue physikalische Übertragungstechnologien, Single Pair Ethernet (SPE) eingesetzt werden. Lange Lebenszyklen von Produktionsanlagen und Automatisierungstechnik führen allerdings dazu, dass die Einführung und Verbreitung neuer Technologien nur langsam erfolgt. Dabei unterliegt die Einführung der genannten Technologien unterschiedlichen Einflüssen: So ist die Einführung von TSN als Netzwerktechnologie gegenüber einer Physical Layer-Technologie, wie Single Pair Ethernet, oder einer Protokolleinführung, wie OPC UA, besonders schwer, da TSN nur dann genutzt werden kann, wenn alle Geräte eines Netzwerkes TSN auch unterstützen. Migrationsstrategien für Feldgeräte sind heute häufig unzureichend. Ein neuer Ansatz für eine verbesserte Migrationsstrategie für Feldgeräte, der die Einführung von Ethernet TSN in die Feldebene ermöglicht, ist der Ethernet Bridge-Modus "Time Aware Forwarding". Time Aware Forwarding vereinfacht die Umsetzung von TSN in Feldgeräte mit zwei Ports. Bestehende PROFINET-Hardware und -Geräte erlangen mit diesem Verfahren die geforderten Funktions- und Leistungsmerkmale, wie Synchronität und geplanter Datenverkehr, um mit TSN-Netzwerken zusammenarbeiten zu können.
  • Publication
    Optimal multispectral sensor confgurations through machine learning for cognitive agriculture
    ( 2021)
    Becker, Florian
    ;
    Backhaus, Andreas
    ;
    Johrden, Felix
    ;
    Flitter, Merle
    Hyperspectral sensor systems play a key role in the automation of work processes in the farming industry. Non-invasive measurements of plants allow for an assessment of the vitality and health state and can also be used to classify weeds or infected parts of a plant. However, one major downside of hyperspectral cameras is that they are not very cost-effective. In this paper, we show, that for specific tasks, multispectral systems with only a fraction of the wavelength bands and costs of a hyperspectral system can lead to promising results for regression and classification tasks. We conclude that for the ongoing automation efforts in the context of cognitive agriculture reduced multispectral systems are a viable alternative.
  • Publication
    Modular and scalable automation for field robots
    ( 2021)
    Osten, Julia
    ;
    Weyers, Catrin
    ;
    Bregler, Kevin
    ;
    Emter, Thomas
    ;
    Petereit, Janko
    This article describes a modular and scalable charging and navigation concept for electrified field robots and other agricultural machines. The concept consists of an underbody charging system on a trailer and a modular navigation box. The underlying conductive charging process is compared to other charging techniques. Charging time in relation to charging current and mean power consumption in field use is displayed. In the navigation box, data of various sensors are combined by means of multi-sensor fusion regarding the precise time of arrival. Time synchronization is achieved by a novel method for compensating the data latency jitter by employing Kalman based timestamp filtering. Furthermore, navigation functionalities, such as motion planning and mapping, are presented.
  • Publication
    New active learning algorithms for near-infrared spectroscopy in agricultural applications
    ( 2021)
    Krause, Julius
    ;
    Günder, Maurice
    ;
    Schulz, Daniel
    ;
    Gruna, Robin
    The selection of training data determines the quality of a chemometric calibration model. In order to cover the entire parameter space of known influencing parameters, an experimental design is usually created. Nevertheless, even with a carefully prepared Design of Experiment (DoE), redundant reference analyses are often performed during the analysis of agricultural products. Because the number of possible reference analyses is usually very limited, the presented active learning approaches are intended to provide a tool for better selection of training samples.
  • Publication
    An approach for Industrie 4.0-compliant and data-sovereign Digital Twins
    ( 2021)
    Jacoby, Michael
    ;
    Volz, Friedrich
    ;
    Weißenbacher, Christian
    ;
    Stojanovic, Ljiljana
    ;
    Usländer, Thomas
    Data sharing between enterprises requires both interoperability and data sovereignty. In the application domain of industrial production an integrated approach is required that encompasses standards and technologies of both Industrie 4.0 and the International Data Spaces(IDS). This paper describes how to combine them for the concept of Digital Twins following the architectural framework given in ISO DIS 23247. Furthermore, an implementation approach is described relying upon the Fraunhofer Advanced AAS Tools for Digital Twins (FA³ST). The resulting architectural approach may be combined with further open manufacturing standards, and may be applied for data analytics and the engineering of AI-based systems.
  • Publication
    Soil monitoring for precision farming using hyperspectral remote sensing and soil sensors
    ( 2021)
    Schreiner, Simon
    ;
    Culibrk, Dubravko
    ;
    Bandecchi, Michele
    ;
    Gross, Wolfgang
    ;
    Middelmann, Wolfgang
    This work describes an approach to calculate pedological parameter maps using hyperspectral remote sensing and soil sensors. These maps serve as information basis for automated and precise agricultural treatments by tractors and field robots. Soil samples are recorded by a handheld hyperspectral sensor and analyzed in the laboratory for pedological parameters. The transfer of the correlation between these two data sets to aerial hyperspectral images leads to 2D-parameter maps of the soil surface. Additionally, rod-like soil sensors provide local3D-information of pedological parameters under the soil surface. The goal is to combine the area-covering 2D parameter maps with the local 3D-information to extrapolate large-scale 3D-parameter maps using AI approaches.
  • Publication
    DecaWave ultra-wideband warm-up error correction
    ( 2021)
    Sidorenko, Juri
    ;
    Schatz, Volker
    ;
    Scherer-Negenborn, Norbert
    ;
    Arens, Michael
    ;
    Hugentobler, Urs
    In the field of indoor localization, ultra-wideband (UWB) technology is no longer dispensable. The market demands that the UWB hardware has to be cheap, precise and accurate. These requirements lead to the popularity of the DecaWave UWB system. The great majority of the publications about this system deals with the correction of the signal power, hardware delay or clock drift. It has traditionally been assumed that this error only appears at the beginning of the operation and is caused by the warm-up process of the crystal. In this article, we show that the warm-up error is influenced by the same error source as the signal power. To our knowledge, no scientific publication has explicitly examined the warm-up error before. This work aims to close this gap and, moreover, to present a solution which does not require any external measuring equipment and only has to be carried out once. It is shown that the empirically obtained warm-up correction curve increases the accuracy for the twoway- ranging (TWR) significantly.
  • Publication
    An intelligent management system for aquaponics
    ( 2021)
    Karimanzira, Divas
    ;
    Rauschenbach, Thomas
    Population rise, climate change, soil degradation, water scarcity, and food security require efficient and sustainable food production. Aquaponics is a highly efficient way of farming and is becoming increasingly popular. However, large scale aquaponics still lack stability, standardization and proof of economical profitability. The EU-INAPRO project helps to overcome these limitations by introducing digitization, enhanced technology, and developing standardized modular scalable solutions and demonstrating the viability of large aquaponics. INAPRO is based on an innovation a double water recirculation system (DRAPS), one for fish, and the other one for crops. In DRAPS, optimum conditions can be set up individually for fish and crops to increase productivity of both. Moreover, the integration of digital technologies and data management in the aquaculture production and processing systems will enable full traceability and transparency in the processes, increasing consumers' trust in aquaculture products. In this paper, the innovations and the digitization approach will be introduced and explained and the key benefits of the system will be emphasized.
  • Publication
    Predictive tracking with improved motion models for optical belt sorting
    ( 2020)
    Pfaff, Florian
    ;
    Pieper, Christoph
    ;
    Maier, Georg
    ;
    Noack, Benjamin
    ;
    Gruna, Robin
    ;
    Kruggel-Emden, Harald
    ;
    Hanebeck, Uwe D.
    ;
    Wirtz, Siegmar
    ;
    Scherer, Viktor
    ;
    Längle, Thomas
    ;
    Beyerer, Jürgen
    Optical belt sorters are a versatile means to sort bulk materials. In previous work, we presented a novel design of an optical belt sorter, which includes an area scan camera instead of a line scan camera. Line scan cameras, which are well-established in optical belt sorting, only allow for a single observation of each particle. Using multitarget tracking, the data of the area scan camera can be used to derive a part of the trajectory of each particle. The knowledge of the trajectories can be used to generate accurate predictions as to when and where each particle passes the separation mechanism. Accurate predictions are key to achieve high quality sorting results. The accuracy of the trajectories and the predictions heavily depends on the motion model used. In an evaluation based on a simulation that provides us with ground truth trajectories, we previously identified a bias in the temporal component of the prediction. In this paper, we analyze the simulation-based ground truth data of the motion of different bulk materials and derive models specifically tailored to the generation of accurate predictions for particles traveling on a conveyor belt. The derived models are evaluated using simulation data involving three different bulk materials. The evaluation shows that the constant velocity model and constant acceleration model can be outperformed by utilizing the similarities in the motion behavior of particles of the same type.