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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Arquitetura de software aviônico de um VANT com requisitos de homologação. / Sem título em inglês

Amianti, Giovani 20 February 2008 (has links)
Recentemente, um crescente número de institutos de pesquisa pelo mundo tem focado seus estudos em veículos aéreos não tripulados (VANT ou, em inglês, UAV - Unmanned Aerial Vehicle), que se revelam muito úteis tanto em aplicações militares quanto civis, pois suas principais vantagens são: a alta confiabilidade, baixo risco à vida, reduzido custo de implantação e manutenção. A pesquisa apresentada neste trabalho integra-se ao projeto BR-UAV em desenvolvimento na empresa Xmobots Sistemas Robóticos LTDA e no Laboratório de Veículos Não Tripulados (LVNT) da Escola Politécnica da USP. O projeto BR-UAV visa a contribuir para a inserção desta tecnologia no país e, para tanto, desenvolve atualmente a plataforma, aviônica e sistema de controle autônomo voltados ao objetivo de monitoramento no espectro visível e infravermelho. O principal requisito do projeto BR-UAV é o desenvolvimento de um sistema aéreo não tripulado capaz de voar dentro do espaço aéreo controlado. Esta pesquisa foca no desenvolvimento do software embarcado, assim este software deve ser desenvolvido de acordo com uma metodologia direcionada a homologação. Por isso, este trabalho propõe uma metodologia que foi baseada em cinco elementos: processo de desenvolvimento, normas, ferramentas de sistema operacional, ferramentas de aplicação e ferramentas matemáticas. Após o estabelecimento dos objetivos, de uma análise do estado da arte em sistemas aviônicos, e da metodologia de certificação, o processo de desenvolvimento foi inicializado. Na fase de engenharia de sistemas, os requisitos de sistema foram capturados. Então a arquitetura de sistema (hardware e software) foi modelada e analisada. A partir desta modelagem de sistema, os requisitos funcionais e temporais de software puderam ser capturados na etapa de análise da fase de engenharia de software. Na etapa de Implementação, o interior dos agentes foi codificado.Além disso, foi implementado o filtro de Kalman estendido para integrar informações de GPS, unidade de medição inercial e bússola. Na etapa de Testes, foram realizados testes de integração funcional e de desempenho computacional. Os resultados demonstraram que o sistema atendeu a todos os requisitos consumindo 38.3% de processamento. Finalmente, os próximos passos desta pesquisa são discutidos. / Recently, an increasing number of research institutes around the world has been focusing their efforts in the study of unmanned aerial vehicles (UAV), which have proved to be very useful both in military and civil applications because of their major advantages: high reliability, reduced risk to life, reduced maintenance and implantation costs. The research presented in this work is part of the BR-UAV project, which is in development at XMobots Sistemas Robóticos LTDA and at the Laboratório de Veículos Não Tripulados of USP (Brazil). This project aims to contribute for the insertion of this technology in Brazil. Particularly, at the present stage, the project includes the development of the platform, avionics and autonomous control system for environment monitoring via visible and infrared spectrums. The main requirement of BR-UAV Project is the development of an unmanned aerial system that could flight in controlled airspace. This research is focused on the development of embedded software, and therefore this software should be developed according to a certification methodology. For this purpose, this work proposes a methodology that was based into five guidelines: development process, norms, operating system tools, application tools and mathematical tools. The development process was started after the statement of objectives and the analysis of the state of art on UAV avionics. In the systems engineering phase, system requirements were captured and then the system architecture (hardware and software) was modeled and analyzed. From the system modeling, the functional and temporal software requirements could be captured in the analysis stage of the software engineering phase. In the Implementation stage, the agents were coded as well as the Extended Kalman Filter for integrating information from GPS, inertial measurement unit and Compass sensors. In the Tests stage, integration tests were performed.The results showed that the system could fulfill requirements using 38.3% of processing consumption. Finally, the next steps of this research are discussed.
132

Formação e manutenção de correntes de retorno: influência da morfologia e das ondas incidentes / Formation and maintenance of rip currents: influence of morphology and waves

Serrao, Pedro Fernandes 26 February 2019 (has links)
Correntes de retorno são fluxos estreitos e intensos posicionados normal ou obliquamente a linha de costa e são a chave para compreender os processos de troca de água entre a zona de surfe e a plataforma interna. O objetivo do presente estudo é avaliar a influência da morfologia e das forçantes externas nos processos de formação e manutenção das correntes de retorno na praia de Maresias (SP). Para tanto, foram integrados diversos métodos como imagens aéreas obtidas através de VANT, levantamentos topográficos e modelagem numérica. Os resultados indicam que a variação longitudinal da morfologia desempenha um papel fundamental na formação e manutenção das correntes de retorno, assim como os parâmetros de ondas incidentes. A porção leste e central da área de estudo se manteve estável quando comparada a porção oeste, em virtude de correntes de retorno controladas pela morfologia, que também intensificaram os processos de erosão e deposição na porção emersa do perfil praial. Já a porção oeste se mostrou mais suscetível a variações do parâmetros de ondas incidentes. Outro fator relevante observado foi o risco para banhistas; as correntes a leste da área de estudo representaram maior risco visto que o regime de saída foi predominante durante todo o experimento e os fluxos permaneceram estáveis por até 1 km. Os resultados mostram ainda que em se tratando dos padrões de correntes de retorno na praia de Maresias (SP), feições morfológicas geradas durante eventos extremos podem sobrepujar o efeito da variação dos parâmetros de ondas incidentes. / Rip currents are narrow and strong flows positioned normal or oblique to the coastline that represent the key to understand the processes of water exchange between the surf zone and the inner shelf. The aim of this study is to assess the influence of the morphology and the external forces in the processes of rip currents formation and maintenance at Maresias beach (SP). Therefore, we combine various methods, sucha as AUV aerial images, topographic surveys and numerical modeling. The results show that the longitudinal variation of the morphology plays a key role in the formation and maintenance of rip currents, as well as the incoming wave parameters. The central and eastern part of the study area were more stable than the west part, due to the rip currents controlled by the bathymetry, which also intensify the processes of erosion and deposition in the beach profile. The western part was more susceptible to variations of the incoming wave parameters. Another relevant factor is related to beach safety; the currents in the central and east part are more dangerous, since they show an exit flow during all the experiment and the flow remained stable up to 1 km. The results also show that in the case of rip currents at Maresias beach (SP), morphological features generated during extreme events can overcome the effect of the incoming waves.
133

Remote Sensing of Soybean Canopy Cover, Color, and Visible Indicators of Moisture Stress Using Imagery from Unmanned Aircraft Systems

Anthony A Hearst (6620090) 10 June 2019 (has links)
Crop improvement is necessary for food security as the global population is expected to exceed 9 billion by 2050. Limitations in water resources and more frequent droughts and floods will make it increasingly difficult to manage agricultural resources and increase yields. Therefore, we must improve our ability to monitor agronomic research plots and use the information they provide to predict impacts of moisture stress on crop growth and yield. Towards this end, agronomists have used reductions in leaf expansion rates as a visible ‘plant-based’ indicator of moisture stress. Also, modeling researchers have developed crop models such as AquaCrop to enable quantification of the severity of moisture stress and its impacts on crop growth and yield. Finally, breeders are using Unmanned Aircraft Systems (UAS) in field-based High-Throughput Phenotyping (HTP) to quickly screen large numbers of small agronomic research plots for traits indicative of drought and flood tolerance. Here we investigate whether soybean canopy cover and color time series from high-resolution UAS ortho-images can be collected with enough spatial and temporal resolution to accurately quantify and differentiate agronomic research plots, pinpoint the timing of the onset of moisture stress, and constrain crop models such as AquaCrop to more accurately simulate the timing and severity of moisture stress as well as its impacts on crop growth and yield. We find that canopy cover time series derived from multilayer UAS image ortho-mosaics can reliably differentiate agronomic research plots and pinpoint the timing of reductions in soybean canopy expansion rates to within a couple of days. This information can be used to constrain the timing of the onset of moisture stress in AquaCrop resulting in a more realistic simulation of moisture stress and a lower likelihood of underestimating moisture stress and overestimating yield. These capabilities will help agronomists, crop modelers, and breeders more quickly develop varieties tolerant to moisture stress and achieve food security.
134

Development of embedded image processing for low-altitude surveillance UAVs to assist operators in their mission / Développement d’un système d’assistance aux opérateurs de mini-drones de surveillance par traitements d’images embarqués

Castelli, Thomas 30 September 2016 (has links)
Cette thèse, effectuée en partenariat entre la société Survey Copter, le laboratoire Hubert Curien et la Direction Générale de l’Armement (DGA), répond à des besoins tant militaires que civils dans le cadre de l’utilisation de drones à basse altitude. Dans un premier temps nous avons focalisé nos recherches sur la détection d’objets mobiles pour les mini-drones de surveillance destinés aux applications militaires, tels que ceux opérés par Survey Copter. Nous présentons d’abord la méthode que nous avons développé qui consiste en une comparaison entre un flot optique et le flot estimé, l’objectif étant de détecter les objets ayant un mouvement différent de celui correspondant à la scène dans sa globalité, et de maximiser la robustesse de cette détection vis-à-vis des problèmes induits par la parallaxe. Puis, nous décrivons le projet général dans lequel s’inscrit cette détection, en détaillant les choix technologiques et compromis qui ont été effectués, l’objectif étant de développer une carte électronique qui puisse être embarquée sur un drone et permettant d’apporter des fonctionnalités d’assistance aux opérateurs. Une seconde partie, réalisée en collaboration avec le Dr. Mubarak Shah, directeur du laboratoire CRCV en Floride, vise à apporter une solution au problème de sécurité qu’engendre le nombre grandissant de micro-drones de loisir évoluant dans l’espace aérien civil. La solution que nous proposons comporte deux étapes, premièrement elle utilise les informations cadastrales pour pré-calculer avant le décollage un plan de vol qui permet d’éviter les zones dangereuses comme les routes. La seconde étape intervient pendant le vol et permet d’adapter localement le plan de vol de façon à éviter le survol des objets mobiles tels que les voitures et piétons. Les résultats encourageants que nous avons obtenus grâce à notre méthode de détection d’objets mobiles ont conduit à une publication dans la conférence ISPA 2015, et notre contribution pour l’utilisation sécurisée de drones dans l’espace aérien civil va faire l’objet d’une soumission à la conférence ICRA 2017 / This thesis, in partnership between Survey Copter (a French company), theHubert Curien laboratory, and the DGA (a compnent of the FrenchMinistry of Defense), aims at providing solutions for low-altitude UAVs for both military and civil applications. We first focus on moving objects detection for military surveillance using mini-UAVs, such as Survey Copter’s products. Our method consists in comparing a dense optical flow with an estimated flow in order to isolate objects that are independently moving compared to the global scene. This method was developed to be robust to parallax which is an inherent problem of such platforms, parallax. In this thesis we also detail an on-going project that consists in the development of an embedded processing board able to provide all necessary functionalities to assist UAV operators in their mission. Given the recent popularity of consumer drones, we worked, with Dr. Mubarak Shah, Director of the CRCV laboratory in Florida, towards providing a solution to the security threat those vehicles represent for public safety. Our method consists in two steps. The first one is performed prior to takeoff by computing the safest path for the mission in order to avoid dangerous areas such as roads. The second is based on an in-flight adaptation process of the initial flight plan to avoid flying above some particular objects such as cars or pedestrians. The promising results obtained thaks to our moving objects detection method have led to a publication in ISPA 2015, and our contribution towards safe navigation of UAVs will be submitted in September to ICRA 2017
135

Proposta de uma arquitetura base para integração de VANT / A proposal for a base architecture for UAV integration.

Guidoti, Fernanda Pereira 19 March 2019 (has links)
O presente documento tem por objetivo apresentar a dissertação desenvolvida no Programa de Mestrado em Ciência da Computação e Matemática Computacional do ICMC/USP. A presente pesquisa busca avançar o estado da arte considerando um conceito chamado arquitetura base que integra Veículos Aéreos Não Tripulados (VANTs) com uma plataforma web, no contexto de arquitetura de software, determina uma arquitetura inicial que se adapta as exigências de cada área. Os estudos também avançam na apresentação de uma plataforma web integrando vários VANTs e agregando diferentes módulos com variações que satisfaça a necessidade para diferentes áreas de aplicações. Com frequência os VANTs são utilizados por inúmeras áreas, como agricultura, segurança, monitoramento ambiental, coleta de dados, cidades inteligentes, entre outras, seja para visualizar imagens, vídeos ou informações de voos e é de extrema importância que essas informações estejam além de acessível bem organizadas. Muitos trabalhos são encontrados na literatura sobre VANT, mas poucos tratam o problema de acesso a informações de voos. Neste trabalho é abordado uma arquitetura de software base para a comunicação e recuperação de informações de VANTs. Para isso, a arquitetura base propõem coletar e processar diferentes informações, ou seja como cada VANT tem suas semelhanças e compartilham estruturas comuns, neste cenário, explorando estas similaridades, é proposto esta arquitetura base. Para validar esta hipótese foi realizado um estudo de caso em duas fazendas com cultivos de mangas, com a finalidade de integrar o VANT, a estação base, a estação local e a estação web, podendo recuperar informações. A principal contribuição do trabalho é o auxílio no desenvolvimento da pesquisa na área de VANTs, além de ter também um ambiente que possa ser utilizado em larga escala por diversos pilotos de VANTs para armazenamento de dados dos voos, parte destes dados ficariam em domínio público e outra parte ficaria disponível apenas ao proprietário do VANT. / This paper aims to present the dissertation developed in the Masters Program in Computer Science and Computational Mathematics of the ICMC / USP. The present research seeks to advance state of the art considering a concept called base architecture that integrates Unmanned Aerial Vehicles (UAV) with a platform in the context of software architecture determines an initial architecture that adapts the requirements of each area. The studies also advance in the presentation of a web platform integrating several UAVs and adding different modules with variations that satisfy the need for different areas of applications. Often the UAVs are used by numerous areas such as agriculture, security, environmental monitoring, data collection, smart cities, among others, whether to view images, videos or flight information and it is of the utmost importance that this information is beyond reach well organized. Many papers are found in the UAV literature, but few address the problem of access to flight information. In this work, a base software architecture for the communication and flight information of UAVs is addressed. For this, the base architecture proposes to collect and process different information, that is how each UAV has its similarities and share common structures, in this scenario, exploring these similarities, this base architecture is proposed. To validate this hypothesis, a case study was carried out on two farms with mango crops, in order to integrate the UAV, the base station, the local station and the web station, and can retrieve flight information. The main contribution of the work is the aid in the development of research in the area of UAVs, in addition to having an environment that can be used in large scale by several pilots of UAVs to store flight data, part of this data would be in the public domain and another part would be available only to the UAV owner.
136

Mission Specialist Human-Robot Interaction in Micro Unmanned Aerial Systems

Peschel, Joshua Michael 2012 August 1900 (has links)
This research investigated the Mission Specialist role in micro unmanned aerial systems (mUAS) and was informed by human-robot interaction (HRI) and technology findings, resulting in the design of an interface that increased the individual performance of 26 untrained CBRN (chemical, biological, radiological, nuclear) responders during two field studies, and yielded formative observations for HRI in mUAS. Findings from the HRI literature suggested a Mission Specialist requires a role-specific interface that shares visual common ground with the Pilot role and allows active control of the unmanned aerial vehicle (UAV) payload camera. Current interaction technology prohibits this as responders view the same interface as the Pilot and give verbal directions for navigation and payload control. A review of interaction principles resulted in a synthesis of five design guidelines and a system architecture that were used to implement a Mission Specialist interface on an Apple iPad. The Shared Roles Model was used to model the mUAS human-robot team using three formal role descriptions synthesized from the literature (Flight Director, Pilot, and Mission Specialist). The Mission Specialist interface was evaluated through two separate field studies involving 26 CBRN experts who did not have mUAS experience. The studies consisted of 52 mission trials to surveil, evaluate, and capture imagery of a chemical train derailment incident staged at Disaster City. Results from the experimental study showed that when a Mission Specialist was able to actively control the UAV payload camera and verbally coordinate with the Pilot, greater role empowerment (confidence, comfort, and perceived best individual and team performance) was reported by a majority of participants for similar tasks; thus, a role-specific interface is preferred and should be used by untrained responders instead of viewing the same interface as the Pilot in mUAS. Formative observations made during this research suggested: i) establishing common ground in mUAS is both verbal and visual, ii) type of coordination (active or passive) preferred by the Mission Specialist is affected by command-level experience and perceived responsibility for the robot, and iii) a separate Pilot role is necessary regardless of preferred coordination type in mUAS. This research is of importance to HRI and CBRN researchers and practitioners, as well as those in the fields of robotics, human-computer interaction, and artificial intelligence, because it found that a human Pilot role is necessary for assistance and understanding, and that there are hidden dependencies in the human-robot team that affect Mission Specialist performance.
137

Self-configuring ad-hoc networks for unmanned aerial systems

Christmann, Hans Claus 01 April 2008 (has links)
Currently there is ongoing research in the field of Mobile Ad-hoc Networks (MANET) for several different scenarios. Research has focused on topology related challenges such as routing mechanisms or addressing systems, as well as security issues like traceability of radio communication or encryption. In addition, there are very specific research interests such as the effects of directional antennas for MANETs or optimized transmission techniques for minimal power consumption or range optimization. Unmanned aerial vehicles (UAVs), and unmanned aerial systems (UAS) in general, need wireless systems in order to communicate. Current UAS are very flexible and allow for a wide spectrum of mission profiles by means of utilizing different UAVs, according to the requirements at hand. Each mission poses special needs and requirements on the internal and external UAS communication and special mission scenarios calling for UAV swarms increase the complexity and require specialized communication solutions. UAS have specific needs not provided by the general research, but are, on the other hand, to diversified to make much use of narrowly focused developments; UAS form a sufficiently large research area for application of MANETs to be considered as an independent group with specialized needs worthy of tailored implementations of MANET principles. MANET research has not tackled a general approach to UAS although some sources show specific applications involving UAVS. This work presents some new aspects for the development of of ad-hoc wireless networks for UAVs and UAS and focuses on their specialties and needs. A general framework for MANET development is proposed. Furthermore, the proposed specific evaluation scenarios provide for a UAS focused comparison of MANET performance.
138

Control of cooperative unmanned aerial vehicles / Έλεγχος συνεργαζόμενων ρομποτικών οχημάτων

Αλέξης, Κώστας 06 October 2011 (has links)
This thesis addresses the problems of design and control of small cooperative unmanned autonomous quadrotor aerial vehicles. A new approach is proposed, for the modeling of the system’s dynamics using linearized Piecewise AffineModels. The Piecewise Affine dynamic–models cover a large part of the quadrotor’s flight envelope while also taking into account the additive effects of environmental disturbances. The effects of aerodynamic forces and moments were also examined. A small quadrotor is designed and developed that emphasizes in the areas of increased on–board computational capabilities, state estimation and modular connectivity. Based on the translational and rotational system’s dynamics: a) a switching model predictive controller, b) an explicitly solved constrained finite time optimal control strategy, and c) a cascade control scheme comprised of classical Proportional Integral Derivative control scheme augmented with angular acceleration feedback, were designed and experimentally tested in order to achieve trajectory tracking under the presence of wind–gusts. The efficiency of the proposed control methods was verified through extended experimental studies. The final quadrotor design utilizes a powerful control unit, a sensor system that provides state estimation based on inertial sensors, ultrasound sonars, GPS and vision chips, and an efficient actuating system. The research effort extended in the field of unmanned aerial vehicles cooperation. Cooperation strategies were proposed in order to address the problems of: a) Forest Fire Monitoring and b) Unknown Area Exploration and Target Acquisition. The Forest FireMonitoring algorithm is formulated based on consensus systems theory formulated as a spatiotemporal rendezvous problem in between the quadrotors. The Area Exploration and Target Acquisition algorithm is formulated based on market–based approaches. / Η συγκεκριμένη διατριβή καταπιάνεται με τα προβλήματα της σχεδίασης και ελέγχου μικρού μεγέθους συνεργαζόμενων μη επανδρωμένων αεροσκαφών με έμφαση στα συστήματα Κάθετης Απογείωσης και Προσγείωσης και ιδιαίτερα στη συστήματα τύπου Quadrotor. Μια νέα προσέγγιση για την μοντελοποίηση της δυναμικής του συστήματος η οποία βασίζεται στη θεωρία των Piecewise Affine συστημάτων προτείνεται. Η μοντελοποίηση με βάση τη θεωρία των Piecewise Affine συστημάτων καλύπτει ένα μεγάλο μέρος του φακέλου πτήσης του αεροσκάφους καθότι συνυπολογίζει μέρος της μη-γραμμικότητας του συστήματος ενώ παράλληλα δίνει τη δυνατότητα να χρησιμοποιηθούν τα ιδιαίτερα ανεπτυγμένα εργαλεία του γραμμικού ελέγχου. Αναπτύσσεται νέα πειραματική πλατφόρμα αεροσκάφους τύπου quadrotor η οποία χαρακτηρίζεται από ιδιαίτερες ικανότητες υπολογιστικής ισχύος, αυτόνομη εκτίμηση κατάστασης, πολλαπλή συνδεσιμότητα και αποδοτικό σύστημα πρόωσης. Η τελική πλατφόρμα quadrotor ελικοπτέρου UPATcopter ενσωματώνει μικρουπολογιστικό σύστημα υψηλών δυνατοτήτων, ειδικά συστήματα εκτίμησης κατάστασης τόσο σε εσωτερικούς όσο και σε εξωτερικούς χώρους μέρος των οποίων αναπτύχθηκε στα πλαίσια της διατριβής και αποδοτικό υποσύστημα πρόωσης. Τρεις διαφορετικοί νόμοι ελέγχου αναπτύχθηκαν και δοκιμάστηκαν πειραματικά. Αρχικά δοκιμάσθηκε ένας Constrained Finite Time Optimal Controller, ο οποίος υπολογίζεται πολύ-παραμετρικά και συνυπολογίζει την επίδραση των περιορισμών εισόδου και κατάστασης. Ο συγκεκριμένος ελεγκτής υπολογίσθηκε με βάση μια οικογένεια Piecewise Affine αναπαραστάσεων του υποσυστήματος προσανατολισμού και δοκιμάσθηκε επιτυγχάνοντας αποδοτικό έλεγχο του προσανατολισμού του σκάφους. Ακολούθως δοκιμάσθηκε ένας Switching Model Predictive Control βασισμένος στην Piecewise Affine μοντελοποίηση του συστήματος ο οποίος επίσης συνυπολογίζει την επίδραση των περιορισμών του συστήματος και του ρόλου των διαταραχών. Με τη χρήση αυτού του ελεγκτή επιτεύχθηκε έλεγχος προσανατολισμού και θέσης του αεροσκάφους τόσο σε άπνοια όσο και υπό την επίδραση ισχυρών διαταραχών ανέμου. Επιπρόσθετα, δοκιμάσθηκε ελεγκτής βασισμένος στη θεωρία PID ελέγχου επαυξημένος με ανάδραση γωνιακής επιτάχυνσης του συστήματος. Τέλος, η έρευνα επεκτάθηκε και στις στρατηγικές συνεργασίας μη επανδρωμένων αεροσκαφών προτείνοντας δύο αλγόριθμους. Συγκεκριμένα προτάθηκε αλγόριθμος για την αντιμετώπιση των προβλημάτων επιθεώρησης δασικής πυρκαγιάς και αλγόριθμος εξερεύνησης μιας άγνωστης περιοχής από ομάδα ετερογενών αεροσκαφών.
139

Development of an integrated avionics hardware system for unmanned aerial vehicle research purposes

Van Wyk, Robin 03 1900 (has links)
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The development of an integrated avionics system containing all the required sensors and actuators for autopilot control is presented. The thesis analyzes the requirements for the system and presents detailed hardware design. The architecture of the system is based on an FPGA which is tasked with interfacing with the sensors and actuators. The FPGA abstracts a microprocessor from these interface modules, allowing it to focus only on the control and user interface algorithms. Firmware design for the FPGA, as well as a conceptualization of the microprocessor software design is presented. Simulation results showing the functionality of firmware modules are presented. / AFRIKAANSE OPSOMMING: Die ontwikkeling van ‘n geïntegreede avionika‐stelsel wat al die vereiste sensors en aktueerders vir outoloods‐beheer bevat, word voorgestel. Die tesis analiseer die vereistes van die stelsel en stel ‘n hardeware‐ontwerp voor. Die argitektuur van die stelsel bevat ‘n FPGA wat ‘n koppelvlak met sensors en aktueerders skep. Die FPGA verwyder die mikroverwerker weg van hierdie koppelvlak modules en stel dit sodoende in staat om slegs op die beheer en gebruikerskoppelvlak‐algoritmes te fokus. Sagteware‐ontwerp vir die FPGA, asook die konseptualisering van die sagtewareontwerp vir die mikroverwerker, word aangebied. Simulasie resultate wat die funksionaliteit van die FPGA‐sagteware modules aandui, word ook voorgestel.
140

Monocular vision assisted autonomous landing of a helicopter on a moving deck

Swart, Andre Dewald 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The landing phase of any helicopter is the most critical part of the whole flight envelope, particularly on a moving flight deck. The flight deck is usually located at the stern of the ship, translating to large heave motions. This thesis focuses on the three fundamental components required for a successful landing: accurate, relative state-estimation between the helicopter and the flight deck; a prediction horizon to forecast suitable landing opportunities; and excellent control to safely unite the helicopter with the flight deck. A monocular-vision sensor node was developed to provide accurate, relative position and attitude information of the flight deck. The flight deck is identified by a distinct, geometric pattern. The relative states are combined with the onboard, kinematic state-estimates of the helicopter to provide an inertial estimate of the flight deck states. Onboard motion prediction is executed to forecast a possible safe landing time which is conveyed to the landing controller. Camera pose-estimation tests and hardware-in-the-loop simulations proved the system developed in this thesis viable for flight tests. The practical flight tests confirmed the success of the monocular-vision sensor node. / AFRIKAANSE OPSOMMING: Die mees kritiese deel van die hele vlug-duurte van ’n helikopter is die landings-fase, veral op ’n bewegende vlugdek. Die vlugdek is gewoonlik geleë aan die agterstewe-kant van die skip wat groot afgee bewegings mee bring. Hierdie tesis ondersoek die drie fundamentele komponente van ’n suksesvolle landing: akkurate, relatiewe toestand-beraming tussen die helikopter en die vlugdek; ’n vooruitskatting horison om geskikte landings geleenthede te voorspel; en uitstekended beheer om die helikopter en vlugdek veilig te verenig. ’n Monokulêre-visie sensor-nodus was ontwikkel om akkurate, relatiewe-posisie en oriëntasie informasie van die vlugdek te verwerf. Die vlugdek is geidentifiseer deur ’n kenmerkende, geometriese patroon. Die relatiewe toestande word met die aan-boord kinematiese toestandafskatter van die helikopter gekombineer, om ’n beraming van die inertiale vlugdek-toestande te verskaf. Aan-boord beweging-vooruitskatting is uitgevoer om moontlike, veilige landingstyd te voorspel en word teruggevoer na die landingsbeheerder. Kamera-orientasie afskat-toetse en hardeware-in-die-lus simulasies het die ontwikkelde sisteem van hierdie tesis lewensvatbaar vir vlug-toetse bewys. Praktiese vlug-toetse het die sukses van die monokulêre-visie sensor-nodus bevestig.

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