06 Fakultät Luft- und Raumfahrttechnik und Geodäsie

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/7

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Institute: search.filters.UBSInstitut.Fakultät Luft- und Raumfahrttechnik und Geodäsie (Institutsübergreifend)Subject: search.filters.subject.620

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    Validation of the safety requirements of the landing gear using fault tree analysis
    (2022) Iven, Leander; Zaidi, Yaseen
    We analyze the functionality of the landing system of a regional aircraft in the extension and cruise flight modes and validate safety requirements through the fault tree analysis. The main landing gear system is captured in the electromechanical-fluidic domain and system behavior is abstracted in an elementary hydraulic circuit. The functional representation is then constructed into a fault tree which allows analysis of the failure propagation originating at different branch terminals, for instance, at the main landing gear actuator which extends the gear and holds it retracted during the cruise, door actuator, door uplocks, and hydraulic power supply. Each component is assigned a failure probability. Each failure mode is abstracted as a top-level event having a probability of failure and through Boolean combinations of component failures in the lower branches. Two reliability aspects considered are the availability to fully lower the landing gear and the integrity of inadvertent gear or door extension while cruising. Architectural changes through undercarriage system reconfiguration and component redundancy have been exploited to improve system failure rates. The analysis determines the overall system failure rate against the flight cycles. The process is agile to accommodate design changes with the evolution of architecture during the systems engineering lifecycle.
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    Modelling vegetation health and its relation to climate conditions using Copernicus data in the City of Constance
    (2024) Khikmah, Fithrothul; Sebald, Christoph; Metzner, Martin; Schwieger, Volker
    Monitoring vegetation health and its response to climate conditions is critical for assessing the impact of climate change on urban environments. While many studies simulate and map the health of vegetation, there seems to be a lack of high-resolution, low-scale data and easy-to-use tools for managers in the municipal administration that they can make use of for decision-making. Data related to climate and vegetation indicators, such as those provided by the C3S Copernicus Data Store (CDS), are mostly available with a coarse resolution but readily available as freely available and open data. This study aims to develop a systematic approach and workflow to provide a simple tool for monitoring vegetation changes and health. We built a toolbox to streamline the geoprocessing workflow. The data derived from CDS included bioclimate indicators such as the annual moisture index and the minimum temperature of the coldest month (BIO06). The biophysical parameters used are leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FAPAR). We used a linear regression model to derive equations for downscaled biophysical parameters, applying vegetation indices derived from Sentinel-2, to identify the vegetation health status. We also downscaled the bioclimatic indicators using the digital elevation model (DEM) and Landsat surface temperature derived from Landsat 8 through Bayesian kriging regression. The downscaled indicators serve as a critical input for forest-based classification regression to model climate envelopes to address suitable climate conditions for vegetation growth. The results derived contribute to the overall development of a workflow and tool for and within the CoKLIMAx project to gain and deliver new insights that capture vegetation health by explicitly using data from the CDS with a focus on the City of Constance at Lake Constance in southern Germany. The results shall help gain new insights and improve urban resilient, climate-adaptive planning by providing an intuitive tool for monitoring vegetation health and its response to climate conditions.