39 research outputs found

    Concept of a Dual Energy Storage System for Sustainable Energy Supply of Automated Guided Vehicles

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    Due to the growing number of automated guided vehicles (AGVs) in use in industry, as well as the increasing demand for limited raw materials, such as lithium for electric vehicles (EV), a more sustainable solution for mobile energy storage in AGVs is being sought. This paper presents a dual energy storage system (DESS) concept, based on a combination of an electrical (supercapacitors) and an electro-chemical energy storage system (battery), used separately depending on the required transport distance. Each energy storage unit (ESU) in this DESS is capable of supplying the AGV completely. The concept takes into account requirements for a complex material flow as well as minimizing the energy storage capacity required for the operation of the AGV. An energy flow analysis is performed and further used as a basis to derive three possible circuit concepts for the technical realization. The circuit concepts are compared to other approaches from related work, differentiating the functionality to hybrid energy storage systems (HESS). The functionality of the concepts was validated by mapping the energy flow states to active circuit components. Finally, an approach for implementing the control strategy as a state machine is given, and conclusions for further investigations are drawn

    Classified AGV Material Flow and Layout Data Set for Multidisciplinary Investigation

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    Automated Guided Vehicles (AGV) are increasingly used in industry to automate material flow tasks. To efficiently operate systems of AGVs, researchers have proposed many different planning and control methods, e.g., for scheduling, dispatching, and routing. The performance of these methods depends on the characteristics of the system, such as transport distances and station operation frequencies. Even though these characteristics strongly influence the algorithms, no classified collection of layout data was found based on a scientific literature review. In this paper, a data set of 72 material flow and layout compositions from the scientific literature (42) and German industry (30) is presented. Each composition in the data set consists of a transport matrix and a distance matrix. To classify the compositions, a holistic taxonomy was established based on distinguishing criteria for material flow and layout compositions known from the scientific literature. The compositions were classified according to the taxonomy. An analysis of the station operation frequency and transport distance distribution data reveals typical characteristics of the compositions as well as variations between the classified compositions. The aim of this data set is to allow benchmarking of planning and control methods, thus increasing the transparency and traceability of scientific work. Furthermore, the analysis of the layouts and their taxonomy allows to compare the methods of different disciplines. By providing standardized, machine readable formats, automatic testing and optimization will be possible

    Challenges in the development of the Laser Metal Deposition process for use in microgravity at the Einstein-Elevator

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    This paper is about the challenges in developing the Laser Metal Deposition process with metal powder for use in microgravity. The modified gravitational conditions are set up for a few seconds using a drop tower, the Einstein-Elevator of the Leibniz University Hannover. In addition to the drop tower, the specially adapted setup of the experiment will be explained. The samples produced in microgravity during this project will demonstrate the influence of gravity on this additive manufacturing process and on the materials used. Thermal analyses using the Ansys software show how the temperature distribution of the manufactured specimens looks over time and what this means for the execution of the experiment

    Lateralization of mesial temporal lobe epilepsy with chronic ambulatory electrocorticography

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    OBJECTIVE: Patients with suspected mesial temporal lobe (MTL) epilepsy typically undergo inpatient video-electroencephalography (EEG) monitoring with scalp and/or intracranial electrodes for 1 to 2 weeks to localize and lateralize the seizure focus or foci. Chronic ambulatory electrocorticography (ECoG) in patients with MTL epilepsy may provide additional information about seizure lateralization. This analysis describes data obtained from chronic ambulatory ECoG in patients with suspected bilateral MTL epilepsy in order to assess the time required to determine the seizure lateralization and whether this information could influence treatment decisions. METHODS: Ambulatory ECoG was reviewed in patients with suspected bilateral MTL epilepsy who were among a larger cohort with intractable epilepsy participating in a randomized controlled trial of responsive neurostimulation. Subjects were implanted with bilateral MTL leads and a cranially implanted neurostimulator programmed to detect abnormal interictal and ictal ECoG activity. ECoG data stored by the neurostimulator were reviewed to determine the lateralization of electrographic seizures and the interval of time until independent bilateral MTL electrographic seizures were recorded. RESULTS: Eighty-two subjects were implanted with bilateral MTL leads and followed for 4.7 years on average (median 4.9 years). Independent bilateral MTL electrographic seizures were recorded in 84%. The average time to record bilateral electrographic seizures in the ambulatory setting was 41.6 days (median 13 days, range 0-376 days). Sixteen percent had only unilateral electrographic seizures after an average of 4.6 years of recording. SIGNIFICANCE: About one third of the subjects implanted with bilateral MTL electrodes required >1 month of chronic ambulatory ECoG before the first contralateral MTL electrographic seizure was recorded. Some patients with suspected bilateral MTL seizures had only unilateral electrographic seizures. Chronic ambulatory ECoG in patients with suspected bilateral MTL seizures provides data in a naturalistic setting, may complement data from inpatient video-EEG monitoring, and can contribute to treatment decisions

    Entwicklung einer mobilen Anwendung zur Produktnachverfolgung im Fertigungsprozess

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    Die Digitalisierung birgt sowohl für den Unternehmer, als auch für den Kunden diverse Vorteile. Als Instrument zur Veranschaulichung dieser Vorteile dienen vor allem Service-Apps, welche bereits von großen Unternehmen beispielsweise zur Produktnachverfolgung etabliert wurden. Das Mittelstand 4.0 – Kompetenzzentrum Hannover legt den Fokus auf kleine und mittelständische Produktionsbetriebe und vermittelt das Potenzial der Digitalisierung im Rahmen von Industrie 4.0. Dies geschieht anhand einer Produktionslinie personalisierter Kugelschreiber und einer zu Demonstrationszwecken entwickelten App für mobile Endgeräte. Konzeptionierung, Entwicklung und Umsetzung dieser App werden genauestens aufgeführt und erläutert. Die App wurde unter dem Betriebssystem Android entwickelt und gliedert sich in sieben Phasen, beginnend mit der Anforderungsanalyse bis hin zur Veröffentlichung im Google Play Store. Während der Unternehmer die Möglichkeit geboten bekommt, Rückschlüsse als Entscheidungshilfe zur effizienteren Gestaltung der Produktion zu nutzen, ist der Kunde in der Lage, seine Aufträge echtzeitnah in der Produktion nachzuverfolgen und gegebenenfalls Änderungen vorzunehmen

    Classified AGV Material Flow and Layout Data Set for Multidisciplinary Investigation

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    Automated Guided Vehicles (AGV) are increasingly used in industry to automate material flow tasks. To efficiently operate systems of AGVs, researchers have proposed many different planning and control methods, e.g., for scheduling, dispatching, and routing. The performance of these methods depends on the characteristics of the system, such as transport distances and station operation frequencies. Even though these characteristics strongly influence the algorithms, no classified collection of layout data was found based on a scientific literature review. In this paper, a data set of 72 material flow and layout compositions from the scientific literature (42) and German industry (30) is presented. Each composition in the data set consists of a transport matrix and a distance matrix. To classify the compositions, a holistic taxonomy was established based on distinguishing criteria for material flow and layout compositions known from the scientific literature. The compositions were classified according to the taxonomy. An analysis of the station operation frequency and transport distance distribution data reveals typical characteristics of the compositions as well as variations between the classified compositions. The aim of this data set is to allow benchmarking of planning and control methods, thus increasing the transparency and traceability of scientific work. Furthermore, the analysis of the layouts and their taxonomy allows to compare the methods of different disciplines. By providing standardized, machine readable formats, automatic testing and optimization will be possible

    Entwicklung einer Versuchsumgebung zur Untersuchung der Herausforderungen in cyber-physischen Intralogistiksystemen

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    The trend towards heterogeneous, decentral systems in intralogistics results in the need for a concept to describe and virtualize assets to enable their interaction. The multi-layer concept of Cyber-Physical Intralogistics Systems (CPIS) is introduced. The system description (descriptive layer) defines the structure of the digital twins and the communication (virtual layer) of physical (robots, periphery) and logical assets (control systems, simulations). To implement this concept, an experimental environment was developed at the Institute for Material Handling and Logistics and the Karlsruhe Institute of Technology. It consists of physical components, such as models of mobile robots or manipulators, and further periphery, such as racks and charging stations. The environment is supplemented by simulations and control software. Use cases for CPIS are to be implemented and tested in this environment. Due to the easily accessible hardware components and the possible scaling of the systems in the simulation, implementation cycles can be reduced, and results can be achieved quickly without requiring a real-world intralogistics system. CPIS can be used to initialize an automated charging process or to exchange perceived position data of system participants. The primary goal is to enable a modular system, add new participants through plug-and-play, and make systems easily changeable.Der Trend zu heterogenen, dezentralen Systemen in der Intralogistik erfordert ein Konzept zur Beschreibung und Virtualisierung von Assets, um deren Interaktion zu ermöglichen. Das mehrschichtige Konzept der Cyber-Physical Intralogistics Systems wird eingeführt. Die Systembeschreibung (Descriptive Layer) definiert die Struktur der digitalen Zwillinge und der Kommunikation (Virtual Layer) von physischen (Roboter, Peripherie) und logischen Assets (Steuerungssysteme, Simulationen). Zur Umsetzung dieses Konzepts wurde am Institut für Fördertechnik und Logistiksysteme des Karlsruher Instituts für Technologie eine Versuchsumgebung entwickelt. Sie besteht aus physischen Komponenten, wie den Modellen mobiler Roboter oder Manipulatoren, und anderen intralogistischen Komponenten, wie Regalen und Ladestationen. Ergänzt wird die Umgebung durch Simulationen und Steuerungssoftware. In dieser Umgebung sollen Anwendungsfälle für CPIS implementiert und getestet werden. Durch die leicht zugänglichen Hardwarekomponenten und die mögliche Skalierung der Systeme in der Simulation können Implementierungszyklen verkürzt und Ergebnisse schnell erzielt werden, ohne dass eine reales Intralogistiksystem benötigt wird. CPIS können zur Initialisierung eines automatisierten Ladevorgangs oder zum Austausch von Positionsdaten aufgenommen durch Systemteilnehmer genutzt werden. Das primäre Ziel ist es, ein modulares System zu ermöglichen, neue Teilnehmer durch Plug-and-Play hinzuzufügen und Systeme wandelbar zu machen
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