Now showing 1 - 7 of 7
  • Publication
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    Design and Development of a Roaming Wireless Safety Emergency Stop
    Modern manufacturing is characterized by a high degree of automation, with autonomous systems also frequently being used. In such environments human intervention in the event of malfunctions or maintenance becomes a rare but also necessary task. When human workers are no longer an integral part of the production process, but only intervene when necessary, e.g., in the case of unexpected machine behavior, appropriate safety solutions will become even more important. This work describes a wireless communication system enabling a flexible and safe emergency stop function for multiple automation cells. A portable emergency stop switch allows seamless transition between different wireless cells, ensuring functional safety. The communication protocol combines IO-Link Wireless features with the safety requirements already implemented in IO-Link Safety. Security requirements are fulfilled through encryption and authentication. The IO-Link Wireless roaming functionality is used to extend the system across several manufacturing cells. An experimental setup confirms the suitability of the system for various applications. The results demonstrate the effectiveness of the handover mechanism and evaluate the potential of the system to improve flexibility, availability and security in dynamic production environments. Future extensions could include the use of AI based evaluation of the radio signals for an intelligent cell handover.
  • Publication
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    An Analysis of Rolling Horizon Multi-Agent Path Finding in Robotic Sorting Systems
    (IEEE, 2023-09)
    Hein, Benedikt
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    Kirchheim, Alice
    The growth of parcel shipments for end-customer delivery led to the emergence of robotic sorting systems, which offer improved flexibility and cost-effectiveness compared to conveyor-based sorting systems. Controlling large fleets of mobile robots for sorting tasks remains a challenge, as it requires solving a complex multi-agent path finding problem. One possible solution is the recently introduced rolling horizon collision resolution framework, which is actively discussed in the literature. However, its configuration to suit robotic sorting systems concerning real-time capabilities and throughput is still the object of ongoing investigation. To address this research gap, this study investigates the application of the rolling horizon collision resolution framework on two types of robotic sorting systems and a parameter study is conducted to assess its potential in terms of real-time capability and sorting performance.
  • Publication
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    Concept for a Real-Time IoT-Architecture for Collision Avoidance in Smart Cities based on the 5G Mobile Technology
    (IEEE, 2023) ;
    Mousavi, Mohammad Reza
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    Trautwein, Ingo
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    Freymann, Andreas
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    Beutelspacher, Christoph
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    Nehrke, Lara
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    Ludwig, Stephan
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    Kirchheim, Alice
    Road traffic significantly increased in the last decades. The avoidance of accidents and the continuity of traffic flow are significant challenges for road mobility. In this paper, a real-time Internet of Things (IoT) architecture is presented for these current road traffic challenges. The presented architecture takes advantage of the emerging 5G mobile technology and relies on infrastructure components so that the presented architecture can be integrated into city infrastructure to become smarter and provide benefits to citizens. A collision warning service is being implemented to warn road users of imminent collisions. The parallel traffic flow optimization will also enable the prioritization of highlighted traffic partici-pants, such as emergency vehicles. By prioritizing pedestrians, bicycles, e-bikes and buses, for example, it will also be possible to achieve specific traffic and climate policy goals. An according smartphone app allows the resulting advantages to be used in the short term. Furthermore, additional actuators such as displays and signal transmitters will integrate all road users, regardless of the specific app usage. By using 5G, these components will also be implemented quickly, flexibly and reliably as infrastructure IoT devices. The paper concludes with a presentation of a research project in which these solutions are currently being implemented.
  • Publication
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    D8.4 Precision Measurement of the Application-dependent Current Consumption of a Wireless Transceiver Chip
    Modern production concepts generate a demand for reliable, fast and secure wireless communication solutions. Therefore, the current consumption should not increase highly due to additional security operations. This paper shows a principle current measurement method exemplarily of a transceiver for IOLink Wireless protocol. The results show that the current consumption increases by about 316 μA when using hardware-based encryption features, whereby an experimental standard deviation of the mean values of about 15 μA was determined.
  • Publication
    Metadata only
    Deep Fading in a Reverberation Chamber for Wireless Device Testing
    Reverberation chambers (RCs) are a feasible option as test environment for evaluation of wireless devices with integrated antenna as they inherently emulate a Rayleigh fading channel. In this paper the dependency of deep fading on the frequency and position/orientation of an equipment under test (EUT) antenna is evaluated for different numbers of RC steps and loading conditions. The measured data were applied to an exemplary standard for wireless communication. The measurement results are highly repeatable and independent of frequency or position/orientation of the EUT and loading conditions.
  • Publication
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    P2.13 Korrelation von wiederholten Messungen in einer Modenverwirbelungskammer
    Modenverwirbelungskammern (MVKn) stellen vielfältig verwendbare, reproduzierbare Messumgebungen dar. Grundsätzlich handelt es sich dabei um elektromagnetisch geschirmte Volumina, in denen sog. Modenrührer eingebracht sind, die ein elektromagnetisches Feld „verwirbeln“, sodass ein Prüfling einer definierten aber statistisch variierenden Umgebung ausgesetzt wird. Die Modenrührer in MVKn können schrittweise zwischen den einzelnen Messzeitpunkten oder kontinuierlich verfahren werden. In diesem Beitrag werden die jeweiligen Eigenschaften von wiederholten Messungen, die sowohl bei kontinuierlichem als auch schrittweisem Betrieb der Modenrührer aufgenommen wurden, betrachtet. Mit Hilfe von Korrelationskoeffizenten wird jeweils die Wiederholbarkeit der aufgenommenen Messwertsequenzen insgesamt untersucht. Darüber hinaus wird die Wiederholbarkeit von Fadingeinbrüchen gesondert betrachtet, da diese einen wesentlichen Einfluss auf Funksysteme haben, die mittels einer MVK charakterisiert werden können. Als Ursache für Abweichungen bei Wiederholungen wird abschließend das zeitliche Verhalten bzw. die Streuungen zwischen den Messzeitpunkten betrachtet.
  • Publication
    Metadata only
    Base Station Antenna Placement of Wireless Sensor/Actuator Networks in Manufacturing Cells
    (2019) ;
    Krush, Dmytro
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    Wattar, Housam
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    Wireless technologies are intensively used in industrial environments and wireless sensor/actuator networks play a key role for highly flexible automation plants, especially within the Industry 4.0 initiative. In order to achieve a highly robust system behavior also an attentive antenna selection and placement within a manufacturing cell is of interest resulting in an enhanced system reserve. In this paper different strategies for base station antenna placement are investigated with the focus on star-topologies, i.e. a central base station and a multitude of remotely located wireless sensors and actuators. A probabilistic approach has been chosen for modeling path loss, multipath fading and coexistence behavior with respect to adjoining manufacturing cells. Also cable attenuation for remote antennas connected to the base station are taken into account.