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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.
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Mission Specialist Human-Robot Interaction in Micro Unmanned Aerial SystemsPeschel, 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.
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Self-configuring ad-hoc networks for unmanned aerial systemsChristmann, 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.
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Control of cooperative unmanned aerial vehicles / Έλεγχος συνεργαζόμενων ρομποτικών οχημάτωνΑλέξης, 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.
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Development of an integrated avionics hardware system for unmanned aerial vehicle research purposesVan 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.
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Monocular vision assisted autonomous landing of a helicopter on a moving deckSwart, 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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Investigation of an aeroelastic model for a generic wing structureCilliers, M. E. 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Computational Aeroelasticity is a complex research field which combines structural
and aerodynamic analyses to describe a vehicle in flight. This thesis investigates the
feasibility of including such an analysis in the development of control systems for unmanned
aerial vehicles within the Electronic Systems Laboratory at the Department
of Electrical and Electronic Engineering at Stellenbosch University.
This is done through the development of a structural analysis algorithm using the
Finite Element Method, an aerodynamic algorithm for Prandtl’s Lifting Line Theory
and experimental work. The experimental work was conducted at the Low-Speed
Wind Tunnel at the Department of Mechanical and Mechatronic Engineering.
The structural algorithm was applied to 20-noded hexahedral elements in a winglike
structure. The wing was modelled as a cantilever beam, with a fixed and a free
end. Natural frequencies and deflections were verified with the experimental model
and commercial software.
The aerodynamic algorithm was applied to a Clark-Y airfoil with a chord of 0:1m
and a half-span of 0:5m. This profile was also used on the experimental model.
Experimental data was captured using single axis accelerometers. All postprocessing
of data is also discussed in this thesis. Results show good correlation
between the structural algorithm and experimental data. / AFRIKAANSE OPSOMMING: Numeriese Aeroelastisiteit is ’n komplekse navorsingsveld waar ’n vlieënde voertuig
deur ’n strukturele en ’n aerodinamiese analise beskryf word. Hierdie tesis ondersoek
die toepaslikheid van hierdie tipe analise in die ontwerp van beheerstelsels vir onbemande
voertuie binne die ESL groep van die Departement Elektriese en Elektroniese
Ingenieurswese by Stellenbosch Universiteit.
Die ondersoek bevat die ontwikkeling van ’n strukturele algoritme met die gebruik
van die Eindige Element Methode, ’n aerodinamiese algoritme vir Prandtl se
Heflynteorie en eksperimentele werk. Die eksperimentele werk is by die Department
Meganiese en Megatroniese Ingensierswese toegepas in die Lae-Spoed Windtonnel.
Die strukturele algoritme maak gebruik van ’n 20-nodus heksahedrale element
om ’n vlerk-tipe struktuur op te bou. Die vlerk is vereenvouding na ’n kantelbalk
met ’n vasgeklemde en ’n vrye ent. Natuurlike frekwensies en defleksies is met die
eksperimentele werk en kommersiële sagteware geverifieer.
Die aerodinamiese algoritme is op ’n Clark-Y profiel met 0:1m koord lengte en ’n
halwe vlerk length van 0:5m geïmplementeer. Die profiel is ook in die eksperimentele
model gebruik.
Die eksperimentele data is met eendimensionele versnellingsmeters opgeneem.
Al die verdere berekeninge wat op ekperimentele data gedoen is, word in die tesis
beskryf. Resultate toon goeie korrelasie tussen die strukturele algoritme en die
eksperimentele data.
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DESENVOLVIMENTO DE UM VEÍCULO AÉREO NÃO TRIPULADO PARA APLICAÇÃO EM AGRICULTURA DE PRECISÃO / THE DEVELOPMENT OF UNMANNED AERIAL VEHICLE FOR AGRICULTURAL FARM PURPOSESMedeiros, Fabrício Ardais 27 January 2007 (has links)
This work presents the development of the unmanned aerial vehicles (UAV) as an important option for the monitoring and remote sensing of agricultural activities. The UAV application in recognition missions has been favored and helped mainly by the its current technological state of development, like reduced cost of manufacturing, reduction in the size and
weight of navigation equipments, and the need of optimizing in the corps production. For a better understanding of this project, the contents were divided into three main subjects,
methodology applied for each state, performance of the prototype, monitoring and processing of acquired aerial images. The development of the UAV was focused into the methodological activities used in the project and as well as in the results generated by its application to assemble the final prototype. The material and the technique used for the production of each component of the final UAV prototype,
is described through modes and phases. Under the project conditions the set prototype and the equipments used with it showed acceptable results. The acquired and processed images by the set UAV and equipments were good enough
for a preliminary analysis of crops and can give support in the identification of blotch and weed invasions in specific areas of them. / Este trabalho apresenta o desenvolvimento dos veículos aéreos não tripulados (VANT) como uma importante opção para o monitoramento e sensoriamento das atividades agrícola. Sua aplicação em missões de reconhecimento vem sendo favorecida e facilitada pelo atual estágio de
desenvolvimento tecnológico, principalmente pela redução do custo e do tamanho dos equipamentos e pela necessidade de otimização da produção. Para o melhor entendimento do projeto na íntegra, dividiu-se em três partes, as quais são:
metodologia aplicada para a construção do protótipo, desempenho do protótipo e monitoramento e tratamento das imagens aéreas capturadas. Seu desenvolvimento procurou ressaltar as atividades metodológicas envolvidas no processo de projeto e os resultados da metodologia aplicada para a construção do protótipo na concepção final, descrito nos módulos e fases em cada um dos componentes fabricados e nos diversos tipos de materiais empregados na construção do VANT. O protótipo, com seus devidos equipamentos, apresentou resultados satisfatórios para as situações
requeridas no projeto e gerou imagens com qualidade suficiente para oferecer informações preliminares de uma determinada área, proporcionando suporte nas atividades agrícolas e o auxílio no planejamento e a tomada de decisões para a localização das manchas nas lavouras.
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Fault-tolerant control of an octorotor unmanned aerial vehicle under actuators failures / Commande tolérante aux fautes lors de pannes de moteurs d’un droneSaied, Majd 08 July 2016 (has links)
La sûreté de fonctionnement est devenue indispensable pour tous les systèmes critiques où des vies humaines sont en jeu (comme l’aéronautique, le ferroviaire, etc.). Ceci a conduit à la conception et au développement des architectures tolérantes aux fautes, l’objectif de ces architectures étant de maintenir un service correct délivré par le système malgré la présence de fautes, et en particulier de garantir la sécurité-innocuité et la fiabilité du système. La tolérance aux fautes sur les drones aériens multirotors a récemment reçu une attention importante de la part de la communauté scientifique. En particulier, plusieurs travaux ont été développés sur la tolérance aux fautes des quadrirotors suite à des fautes partielles sur les actionneurs, et récemment des recherches ont abordé le problème de panne totale de l’un des actionneurs. D’après ces études, il a été montré qu’une défaillance totale d’un actionneur dans un quadrirotor rend le système non complètement contrôlable. Une solution proposée est de considérer des multirotors avec des actionneurs redondants (hexarotors ou octorotors). La redondance inhérente disponible dans ces véhicules est exploitée, en cas de défaillance sur les actionneurs, pour redistribuer les efforts de commande sur les moteurs sains de façon à garantir la stabilité et la contrôlabilité complète du système. Dans ce travail de thèse, des approches pour la conception de systèmes de commande tolérants aux fautes des drones multirotors sont étudiées et appliquées au contrôle des octorotors. Toutefois, les algorithmes sont conçus de manière à être applicables sur les autres types de multirotors avec des modifications mineures. D’abord, une analyse de contrôlabilité de l’octorotor après l’occurrence de défaillances sur les actionneurs est présentée. Ensuite, un module de détection et d’isolation de pannes moteurs basé sur un observateur non-linéaire et les mesures de la centrale inertielle est proposé. Les mesures des vitesses et des courants de moteurs fournis par les contrôleurs de vitesse sont également utilisées dans un autre algorithme de détection pour détecter les défaillances des actionneurs et distinguer les pannes moteurs des pertes des hélices. Un module de rétablissement basé sur la reconfiguration du multiplexage est proposé pour redistribuer les efforts de commande d’une manière optimale sur les actionneurs sains après l’occurrence de défaillances dans le système. Une architecture complète, comprenant la détection et l’isolation des défauts suivie par le rétablissement du système est validée expérimentalement sur un octorotor coaxial puis elle est comparée à d’autres architectures basées sur l’allocation de commande et la tolérance aux fautes passive par mode glissant. / With growing demands for safety and reliability, and an increasing awareness about the risks associated with system malfunction, dependability has become an essential concern in modern technological systems, particularly safety-critical systems such as aircrafts or railway systems. This has led to the design and development of fault tolerant control systems (FTC). The main objective of a FTC architecture is to maintain the desirable performance of the system in the event of faults and to prevent local faults from causing failures. The last years witnessed many developments in the area of fault detection and diagnosis and fault tolerant control for Unmanned Aerial rotary-wing Vehicles. In particular, there has been extensive work on stability improvements for quadrotors in case of partial failures, and recently, some works addressed the problem of a quadrotor complete propeller failure. However, these studies demonstrated that a complete loss of a quadrotor motor results in a vehicle that is not fully controllable. An alternative is then to consider multirotors with redundant actuators (octorotors or hexarotors). Inherent redundancy available in these vehicles can be exploited, in the event of an actuator failure, to redistribute the control effort among the remaining working actuators such that stability and complete controllability are retained. In this thesis, fault-tolerant control approaches for rotary-wing UAVs are investigated. The work focuses on developing algorithms for a coaxial octorotor UAV. However, these algorithms are designed to be applicable to any redundant multirotor under minor modifications. A nonlinear model-based fault detection and isolation system for motors failures is constructed based on a nonlinear observer and on the outputs of the inertial measurement unit. Motors speeds and currents given by the electronic speed controllers are also used in another fault detection and isolation module to detect actuators failures and distinguish between motors failures and propellers damage. An offline rule-based reconfigurable control mixing is designed in order to redistribute the control effort on the healthy actuators in case of one or more motors failures. A complete architecture including fault detection and isolation followed by system recovery is tested experimentally on a coaxial octorotor and compared to other architectures based on pseudo-inverse control allocation and a robust controller using second order sliding mode.
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Arquitetura de software aviônico de um VANT com requisitos de homologação. / Sem título em inglêsGiovani Amianti 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.
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