No description available.

This thesis describes the development of a series of codes for trim and longitudinal stability analysis of a helicopter in forward flight. In general, particular use of these codes can be made for parametric investigation of the effects of the external and internal systems integrated to UH-60 helicopters. However, in this thesis the trim analysis results are obtained for a clean UH-60 configuration and the results are compared with the flight test data that were acquired by ASELSAN, Inc. The first of the developed trim codes, called TRIM-CF, is based on closedform equations which give the opportunity of having quick results. The second code stems from the trim code of Prouty. That code is modified and improved during the course of this study based on the theories outlined in [3], and the resultant code is named TRIM-BE. These two trim codes are verified by solving the trim conditions of the example helicopter of [3]. Since it is simpler and requires fewer input parameters, it is more often more convenient to use the TRIM-CF code. This code is also verified by analyzing the Bo105 helicopter with the specifications given in [2]. The results are compared with the Helisim results and flight test data given in this reference. The trim analysis results of UH-60 helicopter are obtained by the TRIM-CF code and compared with flight test data. A forward flight longitudinal dynamic stability code, called DYNA-STAB, is also developed in the thesis. This code also uses the methods presented in [3]. It solves the longitudinal part of the whole coupled matrix of equations of motion of a helicopter in forward flight. The coupling is eliminated by linearization. The trim analysis results are used as inputs to the dynamic stability code and the dynamic stability characteristics of a forward flight trim case of the example helicopter [3] are analyzed. The forward flight stability code is applied to UH-60 helicopter. The codes are easily applicable to a helicopter equipped with external stores. The application procedures are also explained in this thesis.

Mittels Zeitrafferaufnahmen ist es möglich, einzelne Zellen und deren Nachkommenschaft innerhalb bestimmter Zellkulturen zu verfolgen. Fortgeschrittene Bilderverarbeitungsmethoden gestatten es, diesen Prozess der Zellverfolgung über Hunderte von aufeinanderfolgenden Bildern weitgehend zu automatisieren und baumartige Zelltrajektorien zu erzeugen. Allerdings kommt es dabei häufig zu Situationen, in denen die entsprechenden Algorithmen zu ungenau werden und ein Benutzereingriff erforderlich ist. Ziel dieser Arbeit war ein entsprechendes Softwaretool zu entwickeln, dass diesen Benutzereingriff gewährleistet und damit die automatische Zellverfolgung komplementiert. Die entsprechende Software ist in der Lage , die zu Grunde liegenden Bildstapel zu laden und als Bildsequenz darzustellen. Darüber hinaus werden zusätzliche Informationen zu den erkannten Zellobjekten und den automatisch generierten Zelltrajektoren (vor-prozessierte Metadaten aus Mathematica) geladen und repräsentiert. Zentrale Aufgabe der Software ist es, eine Plattform zu schaffen, auf der ein geschulter Nutzer die erkannten Trajektorienabschnitte effizient und benutzerfreundlich erkennen und gegebenenfalls miteinander verknüpfen kann. Die entsprechend ergänzten Trajektorien können anschliessend als Metadaten für die weitere Verarbeitung und Auswertung zur Verfügung gestellt werden. Das Softwaretool stellt einen wichtigen Bestandteil einer Auswertepipline für zeitlich ausgedehnte Videoaufnahmen von Zellkulturen dar und leistet damit einen Beitrag zum Verständnis von Zellorganisation und zellulärer Migration.

Traditionally, the task of determining aircraft position and attitude for automatic control has been handled by the combination of an inertial measurement unit (IMU) with a Global Positioning System (GPS) receiver. In this configuration, accelerations and angular rates from the IMU can be integrated forward in time, and position updates from the GPS can be used to bound the errors that result from this integration. However, reliance on the reception of GPS signals places artificial constraints on aircraft such as small unmanned aerial vehicles (UAVs) that are otherwise physically capable of operation in indoor, cluttered, or adversarial environments. Therefore, this work investigates methods for incorporating a monocular vision sensor into a standard avionics suite. Vision sensors possess the potential to extract information about the surrounding environment and determine the locations of features or points of interest. Having mapped out landmarks in an unknown environment, subsequent observations by the vision sensor can in turn be used to resolve aircraft position and orientation while continuing to map out new features. An extended Kalman filter framework for performing the tasks of vision-based mapping and navigation is presented. Feature points are detected in each image using a Harris corner detector, and these feature measurements are corresponded from frame to frame using a statistical Z-test. When GPS is available, sequential observations of a single landmark point allow the point's location in inertial space to be estimated. When GPS is not available, landmarks that have been sufficiently triangulated can be used for estimating vehicle position and attitude. Simulation and real-time flight test results for vision-based mapping and navigation are presented to demonstrate feasibility in real-time applications. These methods are then integrated into a practical framework for flight in GPS-denied environments and verified through the autonomous flight of a UAV during a loss-of-GPS scenario. The methodology is also extended to the application of vehicles equipped with stereo vision systems. This framework enables aircraft capable of hovering in place to maintain a bounded pose estimate indefinitely without drift during a GPS outage.

Les phases préliminaires du processus de conception sont celles qui influencent le plus le résultat. Elles sont caractérisées par l’incertitude : le processus ne peut être précisément défini à l’avance. L’approche Design Thinking est particulièrement adaptée pour gérer cette spécificité. L’introduction de supports numérique pendant ces phases de conception préliminaire a été identifiée comme une piste de recherche à fort potentiel. L’analyse de ces phases amont a permis de définir des postulats à partir desquels construire ces nouveaux supports numériques. Ces dispositifs sont constitués de deux surfaces tactiles, multi-utilisateurs ; une orientée horizontalement pour favoriser le foisonnement, l’autre orientée verticalement pour favoriser la focalisation. Par conséquence, ces plateformes ont été identifiées avec l’acronyme HOVER (HORizontale VERticale). La méthodologie de recherche comporte deux phases. Lors de la première phase, des expérimentations ont permis de comparer les dispositifs numériques avec les dispositifs actuels. Cette phase avait pour objectif de déterminer si les dispositifs numériques étaient acceptables dans la situation d’usage préconisée. Lors de la deuxième phase, les dispositifs numériques ont été testés dans des situations de travail réelles, afin de déterminer s’ils améliorent ces situations de travail. Ces expérimentations, ont été faites sur une spécifique plateforme HOVER, dénommés plateforme TATIN-PIC (Table Tactile Interactive –Plateforme Intelligente de Conception), construite à l’Université de Technologie de Compiègne. Les quatre expérimentations de la première phase ont révélées un niveau d’acceptabilité satisfaisant. En outre, cette phase permis d’identifier plusieurs pistes d’amélioration notamment au niveau des interactions homme-machines. La prise en compte des données collectées lors de cette phase a conduit à la conception d’une nouvelle version des dispositifs numériques. Cette nouvelle version, dénommée plateforme Digital Project Space (DPS), a été utilisée pour tester le dispositif dans des situations d’utilisation réelles. Les résultats de ces tests préliminaires montrent que les utilisateurs sont satisfaits des améliorations apportées par la plateforme DPS, et que ses performances, sont au pire, comparable aux meilleures prestations des supports papier actuellement disponibles. Des tests complémentaires sont néanmoins nécessaires pour avoir des résultats généralisables. Les perspectives sont de continuer la dissémination des dispositifs DPS dans la sphère productive afin d’obtenir des données quantitatives sur l’efficacité et l’efficience. L’objectif étant d’identifier des modèles prescriptifs de l’impact des dispositifs sur le processus de conception préliminaire. / The early preliminary phases of the design process are the most impactful on the final outcomes. However, they are ill defined, the path to follow is not clear. Design-thinking approaches are a good solution to tackle the incertitude of these phases. The introduction of computer tools during these phases has been identified as an interesting research path to explore. Through the analysis of these early preliminary design phases, a list of high-level assumptions has been made. These high-level assumptions delimited the perimeter of action for the design of a new kind of computer supported design platforms. These platforms are composed of two multi-touch, multi-users surfaces; one is horizontal to favor divergent thinking, while the other is vertical to favor convergent thinking. By this fact, I identified them with then name “HOVER” (HORizontal - VERtical) platforms. The preconized research methodology has two steps. The first step consists in the experimental comparison of the new tool with existing ones. The aim of this evaluation is to determine if HOVER platforms are applicable to the situation for which they have been designed. The second step consists in ethnographic observations of real case studies to establish if HOVER platforms have successfully improved the existing situation. This study has been conducted on a specific HOVER platform, the TATIN-PIC platform (French acronym for Table Tactile Interactive – Plateforme Intelligente de Conception) built at the Université de Technologie de Compiègne. The first step, composed of four quasi-experimental observations, showed a satisfying level of applicability. Besides, it provided multiple indications for the improvement of the HOVER platforms regarding Human Machine interactions. For example, it has confirmed the need for an interconnected vertical and horizontal surface, the need for a natural manipulation of intermediary objects, the need for a smooth circulation among design methods and, as well, the need for new design methods to be implemented. Thanks to these indications, a second version of a HOVER platform has been made. This improved platform, called Digital Project Space (DPS) platform, has been used for success evaluation in a real context. From these preliminary tests emerged that users are satisfied by the support of the DPS platform. Performances are in the worst-case scenario, as good as actual tools. Further and more accurate real case studies are needed to generalize these findings. This outlines the future perspectives, such as the definition of prescriptive models of the impact of such device on the early preliminary design phases. / Le fasi preliminari del processo di progettazione sono caratterizzate dall’incertezza, sia in termini di conoscenza che di azioni da compiere. Al contempo, pero, sono le fasi cruciali per il risultato globale del processo di progettazione. L’approccio Design Thinking è particolarmente adatto per le caratteristiche di queste fasi. L’introduzione di strumenti digitali durante il processo di progettazione preliminare è stata identificata come una pista di ricerca interessante da esplorare. L’analisi di queste fasi ha permesso di emettere una lista di postulati su cui progettare nuovi strumenti digitali. Questa classe di strumenti ha le sembianze di una piattaforma composta da due superfici tattili multi-utilizzatore; una è orizzontale per favorire il pensiero divergente, mentre l’altra è verticale per favorire il processo convergente. A causa di ciò, abbiamo deciso di identificare queste piattaforme con l’acronimo HOVER (HORizontal and VERtical). Il forte divario in termini di curva d’apprendimento tra i dispositivi esistenti (principalmente basati su carta) e le piattaforme HOVER, ha richiesto la definizione di una metodologia di ricerca adeguata. Questa metodologia ha inoltre il compito di garantire un rigore metodologico nell’approccio di ricerca. Due fasi di questa metodologia sono state eseguite. Nella prima fase, il nuovo dispositivo è comparato sperimentalmente con i dispositivi esistenti al fine di determinare se è applicabile alla situazione per cui è stato concepito. Nella seconda fase, il dispositivo è valutato in una situazione reale al fine di determinare se ha apportato, con successo, un miglioramento alla situazione esistente. Questi studi sono stati condotti su una specifica HOVER platform chiamata TATIN-PIC (acronimo francese per Table Tactile Interactive – Plateforme Intelligente de Conception), progettata e construita all’Université de Technologie de Compiègne. La prima fase, che ha visto quattro esperimenti, ha mostrato un livello di applicabilità soddisfacente, ha inoltre fornito molteplici piste di miglioramento in termini d’interazione uomo macchina. Grazie a questi feedback una seconda versione del dispositivo è stata creata. Tale versione, chiamata piattaforma Digital Project Space (DPS) è stata utilizzata per testare il successo del dispositivo in situazioni di reale utilizzo. Da questi test preliminari è emerso che gli utilizzatori sono rimasti soddisfatti dell’apporto fornito dal dispositivo, e che le performance sono nel caso peggiore equivalenti alla situazione attuale. Ulteriori e approfondite osservazioni di uso in situazioni reale sono necessarie per avere dei riscontri generalizzabili. Questo traccia gli scenari per il futuro; continuando la disseminazione nell’ambito industriale del dispositivo, sarà possibile ottenere dei riscontri quantitativi in termini diefficienza ed efficacia, grazie ai quali, estrapolare dei modelli prescrittivi dell’impatto del dispositivo sul processo di progettazione preliminare.