Blending of Inputs and Outputs for Modal Velocity Feedback

Dynamical systems like mechanical structures can be effectively damped by applying forces which oppose the velocity measured at the very same location. To apply this principle also to systems with multiple actuators and sensors of different type and at different locations, a novel control approach is presented in this paper. The control approach aims to damp individual modes by a minimum-gain feedback of blended measurement outputs to blended control inputs. To that end, a numerically efficient algorithm is proposed for computing input and output blending vectors which yield the desired isolation of the target mode(s). The effectiveness of the proposed approach is demonstrated by increasing the modal damping of an aeroelastic syste

Physik des Skateboardings - Materialabhängige Elastizitätseigenschaften des Skateboard Decks

Zum Zwecke der Kontextualisierung von Physikunterricht existieren zahlreiche Bezüge zu unterschiedlichen Sportarten. Ergänzend zu klassischen Beispielen, wie z.B. dem schiefen Wurf beim Basketball, besitzen insbesondere Sportarten mit einer gewissen Nähe zur Jugendkultur ein großes Potential, um die Auseinandersetzung mit physikalischen Inhalten zu motivieren. So basiert das Skateboarding auf grundlegenden Prinzipien der Mechanik und weist vielfach Bezüge zum Basiskonzept Energie auf. Als Grundlage für den Einbezug eines Sportkontextes in den Physikunterricht gilt es jedoch den physikalischen Hintergrund der jeweiligen Sportart zu klären.Bislang existieren hinsichtlich grundlegender Prinzipien des Skateboardings im Gegensatz zu anderen Sportarten nur in geringem Umfang fachliche Untersuchungen. Auch Hersteller von Skateboards nutzen selten empirische Daten zur Entwicklung von Skateboards, sondern berücksichtigen vor allem praktisches Erfahrungswissen. Der Beitrag widmet sich dieser Forschungslücke durch die experimentelle Analyse zentraler Einflussfaktoren auf die Dynamik skateboardtypischer Bewegungen. Die Untersuchungen umfassen eine experimentelle Kraftanalyse des Kicks und Pops sowie die Messung des Einflusses der Materialzusammensetzung eines Skateboard Decks auf die für das Sprungverhalten grundlegenden Elastizitätseigenschaften eines Skateboards

Physik des Skateboardings - Materialabhängige Elastizitätseigenschaften des Skateboard Decks

Zum Zwecke der Kontextualisierung von Physikunterricht existieren zahlreiche Bezüge zu unterschiedlichen Sportarten. Ergänzend zu klassischen Beispielen, wie z.B. dem schiefen Wurf beim Basketball, besitzen insbesondere Sportarten mit einer gewissen Nähe zur Jugendkultur ein großes Potential, um die Auseinandersetzung mit physikalischen Inhalten zu motivieren. So basiert das Skateboarding auf grundlegenden Prinzipien der Mechanik und weist vielfach Bezüge zum Basiskonzept Energie auf. Als Grundlage für den Einbezug eines Sportkontextes in den Physikunterricht gilt es jedoch den physikalischen Hintergrund der jeweiligen Sportart zu klären.Bislang existieren hinsichtlich grundlegender Prinzipien des Skateboardings im Gegensatz zu anderen Sportarten nur in geringem Umfang fachliche Untersuchungen. Auch Hersteller von Skateboards nutzen selten empirische Daten zur Entwicklung von Skateboards, sondern berücksichtigen vor allem praktisches Erfahrungswissen. Der Beitrag widmet sich dieser Forschungslücke durch die experimentelle Analyse zentraler Einflussfaktoren auf die Dynamik skateboardtypischer Bewegungen. Die Untersuchungen umfassen eine experimentelle Kraftanalyse des Kicks und Pops sowie die Messung des Einflusses der Materialzusammensetzung eines Skateboard Decks auf die für das Sprungverhalten grundlegenden Elastizitätseigenschaften eines Skateboards

Advanced Gust Load Alleviation using Dynamic Control Allocation

Active control techniques play a key role in today's aircraft developments to reduce structural loads during gust encounter and thereby enable highly fuel-efficient aircraft designs. The performance of such gust load alleviation (GLA) systems, however, is often limited by physical limitations in the actuation system. In this paper, a novel GLA control approach is presented which exploits actuator redundancies to avoid performance degradations when individual actuators are driven to their limits or become faulty. To that end, a baseline controller for damping loads-dominating aeroelastic modes is extended with a dynamic control allocation system for handling constrained actuators. Thereby, virtual control inputs, generated for a targeted aeroelastic mode control, are distributed to the actual control inputs in an optimal way. To do so, a convex optimization problem is formulated which is solved in real time with the goal to minimize performance degradations due to actuator constraints. The effectivity of the presented GLA controller is experimentally validated on a highly flexible wing in a wind tunnel considering different actuator constraints and gust excitations at multiple airspeeds

Come, tell me how you live: Habitat suitability analysis for Ostrea edulis restoration

Against the background of the UN decade on ecosystem restoration and the new EU Biodiversity Strategy for 2030, and in the context of marine spatial planning and complex maritime user conflicts, reliable information on habitat suitability for large-scale restoration is an important prerequisite for implementing conservation management and for supporting successful, sustainable, and ecologically efficient restoration measures. In this study, habitat suitability was assessed using multicriteria decision analysis (MCDA) for the restoration of the European oyster, Ostrea edulis, in marine protected areas (MPAs) of the German Bight in the North Sea: Borkum Reef Ground (Borkum Riffgrund, BRG) and Sylt Outer Reef – Eastern German Bight (Sylter Außenriff, SAR). Based on site selection criteria, exclusion and suitability factors for the MCDA were defined. Results were integrated with the available geodata to produce habitat suitability maps for oyster restoration in the area of interest. Suitable as well as unsuitable habitats have been successfully identified for both MPAs: several hundred square kilometres (≥97.2% of BRG) or several thousand square kilometres (≥74.5% of SAR) were classified as ecologically and logistically suitable for oyster restoration measures in the respective MPAs. As oyster restoration is significantly limited by human activities (e.g. bottom trawl fisheries), the management of fisheries is an important prerequisite for successful oyster restoration in both MPAs. Results show that designated fishery management measures will increase the possibilities for oyster restoration. In BRG, our results correspond to the known historical distribution. In SAR, our results significantly exceed the historically known distribution. The habitat suitability analysis will facilitate decision-making regarding ocean use, and will reduce restoration costs through targeted management activities in areas of high suitability and expand species recovery by improving the survival of reintroduced individuals. The habitat suitability analysis procedure is easily adaptable for application to other areas, other species, or other habitat restoration projects, or to other conservation management settings. The software applied is open source and the suitability calculation is described in detail to inform wider applications

Design and wind tunnel test of an actively controlled flexible wing

The reduction of flight loads has the potential to reduce structural mass in wing design and to improve passenger comfort. In the DLR project KonTeKst, an actively controlled wing was designed, manufactured and tested in a wind tunnel experiment. The motivation of the activity was to validate methods for the design of combined passive and active load alleviation techniques, including aeroelastic tailoring and active load control. In addition, the experimental activities provided an opportunity to improve and validate modal identification techniques. The wind tunnel model is a flexible composite wing of 1.6 meter (half-) span, with three flaps used for load control. The control design uses H2 optimal blending techniques for input and output. The control strategy is capable of accounting for failure of one flap without critically losing performance. The wind tunnel experiment was performed in a wind tunnel with a maximum speed of 50 m/s. The paper will give an overview of the numerical design activities for wing and load control, of wing design and manufacturing, including the selection and installation of sensors and actuators, and of the wind tunnel set up including the actuation of the wing, data acquisition and online analysis, as well as selected results

MALDI Profiling of Human Lung Cancer Subtypes

Proteomics is expected to play a key role in cancer biomarker discovery. Although it has become feasible to rapidly analyze proteins from crude cell extracts using mass spectrometry, complex sample composition hampers this type of measurement. Therefore, for effective proteome analysis, it becomes critical to enrich samples for the analytes of interest. Despite that one-third of the proteins in eukaryotic cells are thought to be phosphorylated at some point in their life cycle, only a low percentage of intracellular proteins is phosphorylated at a given time.In this work, we have applied chromatographic phosphopeptide enrichment techniques to reduce the complexity of human clinical samples. A novel method for high-throughput peptide profiling of human tumor samples, using Parallel IMAC and MALDI-TOF MS, is described. We have applied this methodology to analyze human normal and cancer lung samples in the search for new biomarkers. Using a highly reproducible spectral processing algorithm to produce peptide mass profiles with minimal variability across the samples, lineal discriminant-based and decision tree–based classification models were generated. These models can distinguish normal from tumor samples, as well as differentiate the various non–small cell lung cancer histological subtypes.A novel, optimized sample preparation method and a careful data acquisition strategy is described for high-throughput peptide profiling of small amounts of human normal lung and lung cancer samples. We show that the appropriate combination of peptide expression values is able to discriminate normal lung from non-small cell lung cancer samples and among different histological subtypes. Our study does emphasize the great potential of proteomics in the molecular characterization of cancer