NachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
Kueppers. M., S. Paredes Pineda, M. Metzger, Matthias Huber, S. Paulus, H. Heger, S. Niessen
Decarbonization pathways of worldwide energy systems – Definition and modeling of archetypes
Applied Energy, vol. 285, no. 01 March 2021
2021
DOI: 10.1016/j.apenergy.2021.116438
Abstract anzeigen
Energy system models help to find the optimal technology mixes for decarbonization strategies in countries worldwide. To reduce the modeling effort and analyze as many countries as possible, this paper proposes a novel approach of energy system archetypes which can be directly evaluated. These archetypes classify similar countries worldwide independently from their geographic location. Advantages of this idea are the setup of a transferable global database allowing for data reconstruction between countries, market size estimations, and the ability to compare peer countries facing similar challenges. To enable such modeling, a framework is developed in which the archetypes are defined, standardized modeling rules are developed, and the results are evaluated for validation. In a benchmark against simple geographic classifications, the presented clustering approach, which results in 15 archetypes, improves the variance between all countries and their corresponding archetypes by 44% compared to the variance between the countries and their geographic sub-regions. The model results of these archetypes state the need of balancing technologies for the daily cycle of photovoltaic generation and the general importance of flexibility in future decarbonized energy systems. Overall, the results confirm that archetypes are an adequate approach to derive the set of solutions for the decarbonization of worldwide countries.
DigitalTC GrafenauBeitrag (Sammelband oder Tagungsband)
Sebastian Wilhelm
Exploiting Home Infrastructure Data for the good: Emergency Detection by reusing existing Data Sources
[Accepted for publication]
Advances in Intelligent Systems and Computing
2021
Abstract anzeigen
Monitoring people within their residence can enable elderly to live a self-determined life in their own home environment for a longer period of time. Therefore commonly activity profiles of the residents are created using various sensors in the house. Deviations from the typical activity profile may indicate an emergency situation. An alternative approach for monitoring people within their residence we investigates within our research is reusing existing data sources instead of installing additional sensors. In private households there are already numerous data sources such as smart meters weather station routers or voice assistants available. Intelligent algorithms can be used to evaluate this data and conclude on personal activities. This in turn allows the creation of activity profiles of the residents without using external sensor technology.This work outlines the research gap in reusing existing data sources for Human Activity Recognition (HAR) and emergency detection which we intend to fill with our further work.
DigitalTC GrafenauBeitrag (Sammelband oder Tagungsband)
Dietmar Jakob
Acceptance and Practically of Voice Assistance Systems in the everyday life of seniors: A study design
[Accepted for publication]
Advances in Intelligent Systems and Computing
2021
Abstract anzeigen
Voice assistance systems (VAs) are becoming more popular. For Digital Natives these systems are almost part of everyday life. Does this technology also have the potential to facilitate access to digital services for persons aged 55+? Using the example of Amazon's "Echo" devices our research intends to provide a survey of the extent to which VAs are known to the target group how many elderly people own these systems and whether there are any reservations. In addition test persons will be investigated which form of interaction seems easiest for the solution of the tasks and how the operation of VAs differs from the operation of mobile devices to be learned and applied. The evaluation will include statements on socio-demographic and ethnographic aspects. Various Amazon Echo devices are installed in 20 senior households (and additionally in their family households) in order to test user acceptance and its benefits under real-world conditions.
DigitalTC GrafenauBeitrag (Sammelband oder Tagungsband)
Sebastian Wilhelm
Activity-Monitoring in Private Households for Emergency Detection: A Survey of Common Methods and Existing Disaggregable Data Sources
[Accepted for publication]
Proceedings of the 14th International Joint Conference on Biomedical Engineering Systems and Technologies
2021
Abstract anzeigen
Ambient-Assisted Living (AAL) technologies can enable the elderly people to live a self-determined life in their own home environment instead of hospitals and retirement homes for a longer period of time. Hence AAL systems are not only used for everyday support but also for the detection of potential emergency situ- ations and for triggering notification chains. For this purpose the people are usually continuously monitored within their residents by ambient or wearable sensors to detect deviations in their daily behavior.This work surveys common used technologies for Human Activity Recognition (HAR) / Human Presence De- tection (HPD) which is the basis for emergency detection. Furthermore by examining various home automa- tion software existing data sources from the residential infrastructure are identified that would be suitable for detecting personal activities.
DigitalTC GrafenauBeitrag (Sammelband oder Tagungsband)
Sebastian Wilhelm, Dietmar Jakob, Jakob Kasbauer, Diane Ahrens
GeLaP: German Labeled Dataset for Power Consumption
[Accepted for publication]
Proceedings of the 6th International Congress on Information and Communication Technology
2021
Abstract anzeigen
Due to the increasing spread of smart meters numerous researchers are currently working on disaggregating the power consumption data. This procedure is commonly known as Non-Intrusive Load Monitoring (NILM). However most approaches to energy disaggregation first require a labeled dataset to train these algorithms.In this paper we present a new labeled power consumption dataset that was collected in 20 private households in Germany between September 2019 and July 2020. For this purpose the total power consumption of each household was measured with a commercial available smart meter and the individual consumption data of 10 selected household appliances were collected.
NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenZeitschriftenartikel
A. Hamid, J. Sun, H. Zhang, Thomas Stirner
Molecular dynamics simulation analysis of helium cluster growth conditions under tungsten surfaces
Computational Materials Science, vol. 186, no. January
2021
DOI: 10.1016/j.commatsci.2020.109994
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Molecular dynamics simulations have been performed to study the effects of helium fluxes on helium cluster size underneath tungsten surfaces under bombardment of helium atoms with incident energy 30 100 eV at temperature 300 2100 K. The simulation results show that the helium cluster size depends on the magnitude of the helium flux: at a higher flux, the helium clusters on average form in smaller size in tungsten but with larger number; while the clusters form further away from the surface at a lower flux. The coalescence of He atoms and helium bubbles depends on the tungsten temperature: at elevated temperatures around 2000 K, the incident He atoms in tungsten slow down more rapidly than at 1000 K but the number of vacancies per He cluster is smaller. The incident energy has a strong effect on the retention of helium atoms: The helium retention rate increases with the incident energy, and the helium retention depends weakly on temperature in the low energy range of interest. It is also found that the surface orientation plays an important role not only in determining the depth distribution but also in determining the helium retention and cluster size: at the surface {1 1 0}, the retention rate of helium atoms is the lowest, and at the surface {1 1 1}, the clusters grow easily in the lateral direction. The present simulation results suggest that the {0 0 1} surface is favorable for fuzz growth. The results obtained in the present work provide insight to the reasons why the fuzz only grows within a certain parameter range at the atomic level.
NachhaltigEuropan Campus Rottal-InnTC FreyungZeitschriftenartikel
Javier Valdés, Sebastian Wöllmann, Andreas Weber, G. Klaus, Christina Sigl, M. Prem, Robert Bauer, Roland Zink
A framework for regional smart energy planning using volunteered geographic information
Advances in Geosciences, vol. 54, no. 10 December 2020, pp. 179-193
2020
DOI: 10.5194/adgeo-54-179-2020
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This study presents a framework for regional smart energy planning for the optimal location and sizing of small hybrid systems. By using an optimization model – in combination with weather data – various local energy systems are simulated using the Calliope and PyPSA energy system simulation tools. The optimization and simulation models are fed with GIS data from different volunteered geographic information projects, including OpenStreetMap. These allow automatic allocation of specific demand profiles to diverse OpenStreetMap building categories. Moreover, based on the characteristics of the OpenStreetMap data, a set of possible distributed energy resources, including renewables and fossil-fueled generators, is defined for each building category. The optimization model can be applied for a set of scenarios based on different assumptions on electricity prices and technologies. Moreover, to assess the impact of the scenarios on the current distribution infrastructure, a simulation model of the low- and medium-voltage network is conducted. Finally, to facilitate their dissemination, the results of the simulation are stored in a PostgreSQL database, before they are delivered by a RESTful Laravel Server and displayed in an angular web application.
DigitalElektrotechnik und MedientechnikTSZ WeißenburgBeitrag (Sammelband oder Tagungsband)
Alireza Tajafari Sahebi, Amir Samiee, László Juhász
MRAC Implementation for Electric Throttle Valve
Proceedings of the 2020 10th International Conference on Advanced Computer Information Technologies (ACIT) [September 6-8, 2020; Deggendorf]
2020
DOI: 10.1109/ACIT49673.2020.9208929
Abstract anzeigen
Design, implementation and testing of a model reference adaptive controller for an electric throttle valve are presented. An important step by design an adaptive controller is to find an adaptation mechanism. For this purpose, we employed the Lyapunov stability theory. The main challenge in this project originates from a certain term in the updating rules. This term contains the angular velocity, which is not measurable directly. Numerical differentiation of the measured angular position yields a noisy signal. To overcome this problem, we used a non-ideal derivative method. The use of a non-linear state observer based on extended Kalman filter could significantly enhance the control quality. This task is currently in progress.
DigitalFraunhofer AWZ CTMTMaschinenbau und MechatronikZeitschriftenartikel
F. Heilmeier, R. Koos, M. Singer, C. Bauer, Peter Hornberger, Jochen Hiller, W. Volk
Evaluation of Strain Transition Properties between Cast-In Fibre Bragg Gratings and Cast Aluminium during Uniaxial Straining
Sensors, vol. 20, no. 21
2020
DOI: 10.3390/s20216276
Abstract anzeigen
Current testing methods are capable of measuring strain near the surface on structural parts, for example by using strain gauges. However, stress peaks often occur within the material and can only be approximated. An alternative strain measurement incorporates fibre-optical strain sensors (Fiber Bragg Gratings, FBG) which are able to determine strains within the material. The principle has already been verified by using embedded FBGs in tensile specimens. The transition area between fibre and aluminium, however, is not yet properly investigated. Therefore, strains in tensile specimens containing FBGs were measured by neutron diffraction in gauge volumes of two different sizes around the Bragg grating. As a result, it is possible to identify and decouple elastic and plastic strains affecting the FBGs and to transfer the findings into a fully descriptive FE-model of the strain transition area.We thus accomplished closing the gap between the external load and internal straining obtained from cast-in FBG and generating valuable information about the mechanisms within the strain transition area.It was found that the porosity within the casting has a significant impact on the stiffness of the tensile specimen, the generation of excess microscopic tensions and thus the formation of permanent plastic strains, which are well recognized by the FBG. The knowledge that FBG as internal strain sensors function just as well as common external strain sensors will now allow for the application of FBG in actual structural parts and measurements under real load conditions. In the future, applications for long-term monitoring of cast parts will also be enabled and are currently under development.
DigitalFraunhofer AWZ CTMTMaschinenbau und MechatronikZeitschriftenartikel
Jochen Hiller, Peter Landstorfer, Philipp Marx, Matthias Herbst
Evaluation of the impact of faulty scanning trajectories in robot-based x-ray computed tomography
Measurement Science and Technology, vol. 32, no. 1
2020
DOI: 10.1088/1361-6501/abaf2a
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X-ray computed tomography (CT) imaging for industrial applications is limited to certain physical conditions to be fulfilled. The size of the measuring object and the accumulated wall thickness are two fundamental conditions. An omission of these conditions by not capturing object attenuation information by the x-ray detector leads to missing data in the 3D reconstruction process and results as a consequence in image degradation and artifacts. Conventional industrial x-ray CT is based on cone-beam projections and circular or helical scanning trajectories using linear axis and a rotary (lift) table. For many inspection tasks on big-sized or unusually shaped objects the physical limits for obtaining a sufficient high image quality are reached very quickly when using conventional CT systems. Industrial six-axis robots offer much more flexibility with respect to the conditions mentioned earlier and can overcome the limitations of conventional scanners. In the present work we characterized an industrial six-axis robot in its working space following ISO 9283 in terms of pose accuracy and pose repeatability. These results are then used to simulate faulty scanning trajectories in terms of pose deviations where a single robot is used as an object manipulator to rotate virtual specimens on a circular trajectory resulting in different (faulty) reconstruction datasets. These datasets are evaluated visually and by using performance parameters and geometrical features in order to determine the reproduction fidelity (performance) of a one arm robot-based CT system depending on different pose errors. With the results obtained it was shown that a robot-based CT system of type B (in our classification scheme) using one robot as object manipulator should be able to reach a spatial resolution power in the range of the voxel size (in our case 200 µm) and smaller (neglecting effects from focal spot size, detector unsharpness from x-ray to light conversation and scatter radiation) if systematic pose errors are compensated using appropriate calibration methods.
DigitalFraunhofer AWZ CTMTMaschinenbau und MechatronikZeitschriftenartikel
S. Zabler, M. Maisl, Peter Hornberger, Jochen Hiller, C. Fella, R. Hanke
X-ray imaging and computed tomography for engineering applications
tm - Technisches Messen, vol. 87, no. Online veröffentlicht: 08.04.2020
2020
DOI: 10.1515/teme-2019-0151
Abstract anzeigen
After an incremental development which took place over four decades, X-ray imaging has become an important tool for non-destructive testing and evaluation. Computed Tomography (CT) in particular beholds the power of determining the location of flaws and inclusions (e. g. in castings and composites) in three-dimensional object coordinates. Therefore, and thanks to a speed-up of the measurement, CT is now routinely considered for in-line inspection of electronics, castings and composites. When precision and not speed is important, Micro-CT (μCT) can be employed for Dimensional Measurements (DM, e. g. quality assurance and shape verification), as well as for in situ testing, and for characterizing micro-structures in metals and composites. Using appropriate image processing and analysis μCT can determine the local fibre orientation in composites, the granular morphology of battery cathodes or the inter-connectivity of certain phases in casting alloys.
Today, the large variety of X-ray instruments and methods poses an application problem which requires experience and a lot of knowledge for deciding which technique applies best to the task at hand. Application-specific guidelines exist for X-ray radiography testing (RT) only, whereas standardization has been applied to CT, unfortunately leaving out high resolution subμ CT, and nano-CT. For the latter exist an equally high number of NDT applications, however these instruments still necessitate a profound expertise. The task is to identify key industrial applications and push CT from system standardization to application specific automation.
DigitalTC GrafenauZeitschriftenartikel
Ali Fallah-Tehrani
The Choquet Kernel on the use of Regression Problem
Information Sciences, no. 08 December 2020
2020
DOI: 10.1016/j.ins.2020.11.051
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Recently, we have presented a new family of kernels on the basis of the discrete Choquet integral. While a naïve computation of this kernel has an exponential complexity in the number of features, we have proposed an efficient approach with computational complexity of 1. This kernel family is able to recognize dependencies between features and moreover it can be regularized through a proper selection of q-additivity. In fact, to reduce the effect of over-fitting there is an opportunity to restrict the flexibility of kernel to a lower degree. A key feature of the Choquet integral in a data-driven way is its monotonicity, however, this representation does not consider any monotonicity constraint; hence it is versatile for other applications, too. This issue is highlighted in the experimental study. In this regard, we apply the Choquet kernel for regression task and compare the performance of the proposed kernel versus state-of-the-art support kernel-based regression methods as well as random forest.
DigitalMobilTC FreyungBeitrag (Sammelband oder Tagungsband)
M. Novàk, J. Geyer, M. Prokýšek, M. Hais, S. Gril, M. Davidková, P. Doležal, Peter Hofmann, Rajan Paudyal
Construction of a Multisensor UAV System for Early Detection of Forest Pests
Advances in Intelligent Systems and Computing V, Cham, Switzerland, vol. 1293
2020
ISBN: 978-3-030-63270-0
DigitalNachhaltigEuropan Campus Rottal-InnZeitschriftenartikel
Kueppers. M., C. Perau, M. Franken, H. Heger, Matthias Huber, M. Metzger, S. Niessen
Data-Driven Regionalization of Decarbonized Energy Systems for Reflecting Their Changing Topologies in Planning and Optimization
Energies, vol. 13, no. 16
2020
DOI: 10.3390/en13164076
Abstract anzeigen
The decarbonization of energy systems has led to a fundamental change in their topology since generation is shifted to locations with favorable renewable conditions. In planning, this change is reflected by applying optimization models to regions within a country to optimize the distribution of generation units and to evaluate the resulting impact on the grid topology. This paper proposes a globally applicable framework to find a suitable regionalization for energy system models with a data-driven approach. Based on a global, spatially resolved database of demand, generation, and renewable profiles, hierarchical clustering with fine-tuning is performed. This regionalization approach is applied by modeling the resulting regions in an optimization model including a synthesized grid. In an exemplary case study, South Africa’s energy system is examined. The results show that the data-driven regionalization is beneficial compared to the common approach of using political regions. Furthermore, the results of a modeled 80% decarbonization until 2045 demonstrate that the integration of renewable energy sources fundamentally changes the role of regions within South Africa’s energy system. Thereby, the electricity exchange between regions is also impacted, leading to a different grid topology. Using clustered regions improves the understanding and analysis of regional transformations in the decarbonization process.
NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH TeisnachBeitrag (Sammelband oder Tagungsband)
Christian J. Trum, M. Jung, Beate Schmidbauer, Sebastian Sitzberger, E. Willenborg, Rolf Rascher
Hybrid-process-chain for polishing optical glass lenses – HyoptO
Proceedings of SPIE Optical Engineering + Applications (24 August - 04 September, 20208; Optical Manufacturing and Testing XIII; online conference), San Diego, United States, vol. 11487
2020
DOI: 10.1117/12.2568400
Abstract anzeigen
A number of process steps that build on one another are required to manufacture optical components from glass. The polishing steps are the most time-consuming and therefore cost-intensive parts of the process chain. Low removal rates and the depth of the Sub Surface Damage (SSD) to be removed contribute to this. An alternative for the complete removal of the SSD-penetrated material using contactless polishing methods such as Ion Beam Figuring (IBF) is the healing of the SSD. Due to the induced energy during laser-polishing, the material is remelted at the defects and the SSD are closed. However, laser-polishing is also associated with disadvantages in terms of shape accuracy and surface quality. The project HyoptO is therefore devoted to the development of a hybrid-process-chain consisting of laser processing and conventional polishing. It is expected that the healing times of the SSD can significantly reduce the process times in the subsequent polishing steps. However, there are a few questions to be answered regarding the economic use of the hybrid-process-chain. These include:
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