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Control allocation as part of a fault-tolerant control architecture for UAVsBasson, Lionel 03 1900 (has links)
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The development of a control allocation system for use as part of a fault-tolerant control
(FTC) system in unmanned aerial vehicles (UAVs) is presented. This system plays a
vital role in minimising the possibility that a fault will necessitate the reconfiguration of
the control, guidance or navigation systems of the aircraft by minimising the difference
between the desired and achievable aircraft performance parameters. This is achieved
by optimising the allocation of control effort commanded by the virtual actuators to the
physical actuators present on the aircraft.
A simple general six degree of freedom aircraft model is presented that contains all of
the relevant terms needed to find the trim biases of the aircraft actuators and evaluate
the performance of the virtual actuators. This model was used to develop a control
allocation formulation that optimises the performance of the virtual actuators of the
aircraft while minimising adverse effects and avoiding actuator saturation. The resulting
problem formulation was formulated as a multi-objective optimisation problem which was
solved using the sequential quadratic programming method.
The control allocation system was practically implemented and tested. A number of
failure categories of varying severity were defined and two aircraft with different levels
of actuator redundancy were used to test the system. The control allocation algorithm
was evaluated for each failure category, aircraft test case and for a number of differing
control allocation system configurations. A number of enhancements were then made
to the control allocation system which included adding frequency-based allocation and
adapting the algorithm for an unconventional ducted-fan UAV.
The control allocation system is shown to be applicable to a number of different conventional
aircraft configurations with no alterations as well as being applicable to unconventional
aircraft with minor alterations. The control allocation system is shown to
be capable of handling both single and multiple actuator failures and the importance of
actuator redundancy is highlighted as a factor that influences the effectiveness of control
allocation. The control allocation system can be effectively used as part of a FTC system
or as a tool that can be used to investigate control allocation and aircraft redundancy. / AFRIKAANSE OPSOMMING: Die ontwikkeling van ’n beheertoekenning sisteem vir gebruik as deel van ’n fout verdraagsame
beheersisteem in onbemande lugvaartuie word voorgelê. Hierdie sisteem speel
’n essensiële rol in die vermindering van die moontlikheid dat ’n fout die herkonfigurasie
van die beheer, bestuur of navigasiesisteme van die vaartuig tot gevolg sal hê, deur die
verskil te verminder tussen die verlangde en bereikbare werkverrigtingsraamwerk van die
vaartuig. Dit word bereik deur die optimisering van die toekenning van beheerpoging
aangevoer deur die virtuele aktueerders na die fisiese aktueerders teenwoordig op die
vaartuig.
’n Eenvoudige algemene ses grade van vryheid lugvaartuig model word voorgestel wat
al die relevante terme bevat wat benodig word om die onewewigtigheid verstelling van
die vaartuig se aktueerders te vind en die werksverrigting van die virtuele aktueerders
te evalueer. Hierdie model is gebruik om ’n beheer toekenning formulering te ontwikkel
wat die werkverrigting van die virtuele aktueerders van die vaartuig optimiseer terwyl
nadelige gevolge verminder word asook aktueerder versadiging vermy word. Die gevolglike
probleem formulering is omskryf as ’n multi-doel optimiserings probleem wat opgelos is
deur gebruik van die sekwensiële kwadratiese programmerings metode.
Die beheertoekenning sisteem is prakties geïmplementeer en getoets. ’n Aantal fout kategorieë
van verskillende grade van erns is gedefinieer en twee vaartuie met verskillende
vlakke van aktueerder oortolligheid is gebruik om die sisteem te toets. Die beheer toekenning
algoritme is geëvalueer vir elke fout kategorie, vaartuig toetsgeval, asook vir ’n aantal
verskillende beheertoekenning sisteem konfigurasies. ’n Aantal verbeterings is aangebring
aan die beheertoekenning sisteem, naamlik die toevoeging van frekwensie gebaseerde
toekenning en wysiging van die algoritme vir ’n onkonvensionele onbemande geleide waaier
lugvaartuig.
Die beheertoekenning sisteem is van toepassing op ’n aantal verskillende konvensionele
vaartuig konfigurasies met geen verstellings asook van toepassing op onkonvensionele
vaartuie met geringe verstellings. Die beheertoekenning sisteem kan beide enkel- en
veelvoudige aktueerder tekortkominge hanteer en die belangrikheid van aktueerder oortolligheid is beklemtoon as ’n faktor wat die effektiwiteit van beheertoekenning beïnvloed.
Die beheertoekenning sisteem kan effektief geïmplementeer word as deel van ’n fout verdraagsame
beheersisteem of as ’n werktuig om beheertoekenning en vaartuig oortolligheid
te ondersoek.
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An analysis and comparison of two methods for UAV actuator fault detection and isolationOdendaal, Hendrik Mostert 12 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Fault detection and isolation (FDI) is an important aspect of effective fault tolerant control
architectures. The Electronic System Laboratory at Stellenbosch University identified the
need to study viable methods of FDI. In this research two FDI methods for actuator failures
on the Meraka Modular UAV are investigated.
The Meraka Modular UAV is an unmanned aircraft that was developed by the CSIR. A
simple six degree of freedom non-linear mathematical model is developed that presents a
platform on which the two FDI methods are formulated. The theoretical model is used in
a simulation environment to extensively test and compare the performance of the proposed
FDI methods in different types of flight conditions.
The first method investigated is a multiple model adaptive estimator (MMAE), which incorporates
a bank of Kalman filters. Each Kalman filter in the MMAE is conditioned for
each expected actuator fault scenario. The limitations of using linear Kalman filters are explained
and they are replaced by extended Kalman filters, whose associated advantages and
disadvantages are discussed. Each filter in the bank of Kalman filters produces a residual
vector and residual covariance matrix. This information is subjected to a Bayes classifier to
determine the fault scenario which will have the highest likelihood of being active.
The second method that is studied incorporates the parity space approach for FDI. The
parity space consists of the parity relations that quantify all the analytical redundancies
available between the sensors’ outputs and actuator inputs of a system. A transformation
matrix is then optimised to transform these parity relations into residuals that are specially
sensitive to specific actuator faults. Actuator faults cause the parity space residuals’ variance
to increase. A cumulative summation procedure is used to determine when the residuals’
variance has changed sufficiently to indicate an actuator fault. A pseudoinverse actuator
estimation scheme is used to extract the actuator deflections from the parity relations.
The FDI performance is tested by deliberately failing specific actuators of the Meraka Modular
UAV in-flight. The flight test data is then used to analyse and compare the performance
of the two FDI methods investigated in the research. It is found that, for the specific
Meraka Modular UAV, the FDI performs as expected with disturbance effects and actuator
excitation influencing the FDI effectiveness. The research shows that the bank of Kalman
filters creates less false alarms whereas the parity space FDI is more sensitive to faults. It
is illustrated that FDI can be improved with active actuator excitation and process noise
estimation techniques, delivering promising results. / AFRIKAANSE OPSOMMING: Fout-deteksie en -isolasie (FDI) is belangrik vir ’n stelsel se beheerder om foute te kan
hanteer. Die Elektroniese Stelsellabaratorium (ESL) by die Universiteit van Stellenbosch
het die behoefte geïdentifiseer om te gaan kyk na moontlike FDI-stelsels wat gebruik kan
word op hul onbemande vliegtuie (OV). In hierdie navorsing is daar na twee FDI-metodes
gekyk wat op die Meraka Modulêre OV toegepas kan word.
Die Meraka Modulêre OV is ’n vliegtuig wat deur die WNNR ontwikkel is. ’n Eenvoudige sesgrade-
van-vryheid, nie-liniêre wiskundige model van die Meraka Modulêre OV is ontwikkel,
en die FDI-metodes is rondom hierdie model geformuleer. Die teoretiese model is gebruik
in ’n simulasie-omgewing en die werkverrigting van die twee FDI-metodes is in verskillende
vlug-omstandighede getoets en vergelyk.
Die eerste metode waarna gekyk is, was ’n multi-model aanpasbare afskatter (MMAA), wat
’n bank van Kalman-filters gebruik. Elke Kalman-filter in die MMAA is gekondisioneer
vir elke denkbare aktueerder-fout. Die beperkinge rondom liniêre Kalman-filters is uitgelig
en vergelyk met uitgebreide Kalman-filters, waarvan die voor- en nadele bespreek is. Elke
filter in die MMAA produseer ’n residu-vektor en residu-kovariansiematriks. Hierdie informasie
is na ’n Bayes-klassifiseerder gestuur om te bepaal watter fout-senario die grootste
waarskynlikheid het om aktief te wees.
Die tweede metode waarna gekyk is, het die pariteitsruimte vir FDI gebruik. Die pariteitsruimte
is uit al die pariteitsverwantskappe opgebou wat die verhoudings tussen al die insette
en uitsette van ’n sisteem kwantifiseer. ’n Transformasie-matriks is geoptimaliseer om hierdie
pariteitsverwantskappe te transformeer na residue wat elkeen sensitief is tot ’n spesikiefe
aktueerderfout. ’n Spesifieke aktueerderfout veroorsaak dat ’n spesifieke residu se variansie
verhoog. ’n Kummulatiewe sommeringsproses is dan gebruik om te bepaal of die variansie
genoegsaam toegeneem het. Sodoende kon daar bepaal word of ’n fout ontstaan het. ’n
Pseudo-inversaktueerder-afskattingstegniek is gebruik om die afgeskatte aktueerderdefleksie
uit die pariteitsverwantskappe te onttrek.
Die FDI-werkverrigtinge van die twee metodes is getoets deur sekere aktueerders met opset
te laat faal gedurende vlugtoetse. Die vlugtoetsdata is gebruik om die werkverrigting van die
FDI-metodes te analiseer en met mekaar te vergelyk. Met die spesifieke Meraka Modulêre
OV is, soos te wagte, bevind dat versteurings en aktueerderopwekking ’n groot invloed op
die FDI’s se werkverrigtinge toon.
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Kinodynamic planning for a fixed-wing aircraft in dynamic, cluttered environments : a local planning method using implicitly-defined motion primitivesCowley, Edwe Gerrit 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: In order to navigate dynamic, cluttered environments safely, fully autonomous Unmanned
Aerial Vehicles (UAVs) are required to plan conflict-free trajectories between two states
in position-time space efficiently and reliably. Kinodynamic planning for vehicles with
non-holonomic dynamic constraints is an NP-hard problem which is usually addressed
using sampling-based, probabilistically complete motion planning algorithms. These algorithms
are often applied in conjunction with a finite set of simple geometric motion
primitives which encapsulate the dynamic constraints of the vehicle. This ensures that
composite trajectories generated by the planning algorithm adhere to the vehicle dynamics.
For many vehicles, accurate tracking of position-based trajectories is a non-trivial
problem which demands complicated control techniques with high energy requirements.
In an effort to reduce control complexity and thus also energy consumption, a generic
Local Planning Method (LPM), able to plan trajectories based on implicitly-defined motion
primitives, is developed in this project. This allows the planning algorithm to construct
trajectories which are based on simulated results of vehicle motion under the
control of a rudimentary auto-pilot, as opposed to a more complicated position-tracking
system. The LPM abstracts motion primitives in such a way that it may theoretically be
made applicable to various vehicles and control systems through simple substitution of
the motion primitive set.
The LPM, which is based on a variation of the Levenberg-Marquardt Algorithm (LMA),
is integrated into a well-known Probabilistic Roadmap (PRM) kinodynamic planning algorithm
which is known to work well in dynamic and cluttered environments. The complete
motion planning algorithm is tested thoroughly in various simulated environments,
using a vehicle model and controllers which have been previously verified against a real
UAV during practical flight tests. / AFRIKAANSE OPSOMMING: Ten einde dinamiese, voorwerpryke omgewings veilig te navigeer, word daar vereis dat
volledig-outonome onbemande lugvoertuie konflikvrye trajekte tussen twee posisie-tydtoestande
doeltreffend en betroubaar kan beplan. Kinodinamiese beplanning is ’n NPmoeilike
probleem wat gewoonlik deur middel van probabilisties-volledige beplanningsalgoritmes
aangespreek word . Hierdie algoritmes word dikwels in kombinasie met ’n
eindige stel eenvoudige geometriese maneuvers, wat die dinamiese beperkings van die
voertuig omvat, ingespan. Sodanig word daar verseker dat trajekte wat deur die beplaningsalgoritme
saamgestel is aan die dinamiese beperkings van die voertuig voldoen.
Vir baie voertuie, is die akkurate volging van posisie-gebaseerde trajekte ’n nie-triviale
probleem wat die gebruik van ingewikkelde, energie-intensiewe beheertegnieke vereis.
In ’n poging om beheer-kompleksiteit, en dus energie-verbruik, te verminder, word ’n generiese
plaaslike-beplanner voorgestel. Hierdie algoritme stel die groter kinodinamiese
beplanner in staat daartoe om trajekte saam te stel wat op empiriese waarnemings van
voertuig-trajekte gebaseer is. ’n Eenvoudige beheerstelsel kan dus gebruik word, in
teenstelling met die meer ingewikkelde padvolgingsbeheerders wat benodig word om
eenvoudige geometriese trajekte akkuraat te volg. Die plaaslike-beplanner abstraeer
maneuvers in so ’n mate dat dit teoreties op verskeie voertuie en beheerstelsels van
toepassing gemaak kan word deur eenvoudig die maneuver-stel te vervang.
Die plaaslike-beplanner, wat afgelei is van die Levenberg-Marquardt-Algoritme (LMA),
word in ’n welbekende “Probabilistic Roadmap” (PRM) kinodinamiese-beplanningsalgoritme
geïntegreer. Dit word algemeen aanvaar dat die PRM effektief werk in dinamiese, voorwerpryke
omgewings. Die volledige beplanningsalgoritme word deeglik in verskeie, gesimuleerde
omgewings getoets op ’n voertuig-model en -beheerders wat voorheen vir
akkuraatheid teenoor ’n werklike voertuig gekontroleer is tydens praktiese vlugtoetse.
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Online system identification for fault tolerant control of unmanned aerial vehiclesAppel, Jean-Paul 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: In this thesis the strategy for performing System Identification on an aircraft is presented. The
ultimate aim of this document is to outline the steps required for successful aircraft parameter
estimation within a Fault Tolerant Control Framework.
A brief derivation of the classical 6 degree-of-freedom aircraft model is firstly presented. The
derivation gives insight into the aircraft dynamics that are to be used to estimate the aircraft
parameters, and provides a basis for the methods provided in this thesis.
Different techniques of System Identification were evaluated, resulting in the choice of the
Regression method to be used. This method, based on the Least-Squares method, is chosen
because of its simplicity of use and because it does not require as much computational time as
the other methods presented. Regression methods, including a recursive algorithm, are then
applied to aircraft parameter estimation and practical considerations such as Identifiability and
corrupted measurements are highlighted.
The determination of unknown measurements required for System Identification of aircraft
parameters is then discussed. Methods for both estimating and measuring the Angle-of-Attack
(AoA) and angular accelerations are presented. The design and calibration of an AoA probe
for AoA measurements, as well as a novel method that uses distributed sensors to determine
the angular accelerations is also presented.
The techniques presented in this thesis are then tested on a non-linear aircraft model. Through
simulation it was shown that for the given sensor setup, the methods do not provide
sufficiently accurate parameter estimates. When using the Regression method, obtaining
measurements of the angle-of-attack solely through estimation causes problems in the
estimation of the aerodynamic lift coefficients.
Flight tests were performed and the data was analyzed. Similar issues as experienced with
estimation done on the non-linear aircraft simulation, was found. Recommendations with
regards to how to conduct future flight tests for system identification is proposed and possible sources of errors are highlighted. / AFRIKAANSE OPSOMMING: In hierdie tesis word die strategie vir die uitvoering van Stelsel Identifikasie op 'n vliegtuig
aangebied. Die uiteindelike doel van hierdie document is om die stappe wat nodig is vir 'n
suksesvolle vliegtuig parameter beraming, binne 'n Fout Tolerante Beheer Raamwerk, uit
eente sit.
'n Kort afleiding van die klassieke 6 graad-van-vryheid vliegtuig model word eerstens
aangebied. Die afleiding gee insig in die vliegtuig dinamika wat gebruik moet word om die
vliegtuig parameters te beraam, en bied 'n basis vir die metodes wat in hierdie tesis verskyn.
Verskillende tegnieke van Stelsel Identifikasie is geëvalueer, wat lei tot gebruik van die
regressie-metode. Hierdie metode is gekies as gevolg van sy eenvoudigheid en omdat dit nie
soveel berekening tyd as die ander metodes vereis nie. Regressie metodes, insluitend 'n
rekursiewe algoritme, word dan toegepas op vliegtuig parameter beraming en praktiese
orwegings soos identifiseerbaarheid en korrupte metings word uitgelig.
Die bepaling van onbekende afmetings wat benodig is, word vir Stelsel Identifisering van die
vliegtuig parameters bespreek. Metodes om die invalshoek en hoekige versnellings te meet en
beraam, word aangebied. Die ontwerp en kalibrasie van 'n invalshoek sensor vir invalshoek
metings, sowel as 'n nuwe metode wat gebruik maak van verspreide sensore om die
hoekversnellings te bepaal, word ook aangebied.
Die tegnieke wat in hierdie tesis aangebied is, word dan op 'n nie-lineêre vliegtuig model
getoets. Deur simulasie is dit getoon dat die metodes vir die gegewe sensor opstelling nie
voldoende akkurate parameters beraam nie. Dit is ook bewys dat met die gebruik van die
Regressie metode, die vekryging van metings van die invalshoek slegs deur skatting,
probleme in die beraming van die aerodinamiese lug koëffisiente veroorsaak.
Die tegnieke wat in hierdie tesis verskyn, word dan op werklike vlug data toegepas.Vlugtoetse
is uitgevoer en die data is ontleed. Aanbeveling met betrekking tot hoe om toekomstige vlug
toetse vir Stelsel Identifikasiete word voorgestel, en moontlike bronne van foute word uitgelig.
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Motion planning algorithms for autonomous navigation for a rotary-wing UAVBeyers, Coenraad Johannes 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: This project concerns motion planning for a rotary wing UAV, where vehicle controllers are
already in place, and map data is readily available to a collision detection module. In broad
terms, the goal of the motion planning algorithm is to provide a safe (i.e. obstacle free)
flight path between an initial- and goal waypoint. This project looks at two specific motion
planning algorithms, the Rapidly Exploring Random Tree (or RRT*), and the Probabilistic
Roadmap Method (or PRM).
The primary focus of this project is learning how these algorithms behave in specific environments
and an in depth analysis is done on their differences. A secondary focus is the
execution of planned paths via a Simulink simulation and lastly, this project also looks at
the effect of path replanning.
The work done in this project enables a rotary wing UAV to autonomously navigate an
uncertain, dynamic and cluttered environment. The work also provides insight into the
choice of an algorithm for a given environment: knowing which algorithm performs better
can save valuable processing time and will make the entire system more responsive. / AFRIKAANSE OPSOMMING: ’n Tipiese vliegstuuroutomaat is daartoe in staat om ’n onbemande lugvaartvoertuig (UAV)
so te stuur dat ’n stel gedefinieerde punte gevolg word. Die punte moet egter vooraf beplan
word, en indien enige verandering nodig is (bv. as gevolg van veranderinge in die omgewing)
is dit nodig dat ’n menslike operateur betrokke moet raak. Vir voertuie om ten volle
outonoom te kan navigeer, moet die voertuig in staat wees om te kan reageer op veranderende
situasies. Vir hierdie doel word kinodinamiese beplanningsalgoritmes en konflikdeteksiemetodes
gebruik.
Hierdie projek behels kinodinamiese beplanningsalgoritmes vir ’n onbemande helikopter,
waar die beheerders vir die voertuig reeds in plek is, en omgewingsdata beskikbaar is vir
’n konflikdeteksie-module. In breë terme is die doel van die kinodinamiese beplanningsalgoritme
om ’n veilige (d.w.s ’n konflikvrye) vlugpad tussen ’n begin- en eindpunt te vind.
Hierdie projek kyk na twee spesifieke kinodinamiese beplanningsalgoritmes, die “Rapidly
exploring Random Tree*” (of RRT*), en die “Probabilistic Roadmap Method” (of PRM).
Die primêre fokus van hierdie projek is om die gedrag van hierdie algoritmes in spesifieke
omgewings te analiseer en ’n volledige analise te doen op hul verskille. ’n Sekondêre fokus is
die uitvoering van ’n beplande vlugpad d.m.v ’n Simulink-simulasie, en laastens kyk hierdie
projek ook na die effek van padherbeplanning.
Die werk wat gedoen is in hierdie projek stel ’n onbemande helikopter in staat om outonoom
te navigeer in ’n onsekere, dinamiese en besige omgewing. Die werk bied ook insig in die
keuse van ’n algoritme vir ’n gegewe omgewing: om te weet watter algoritme beter uitvoertye
het kan waardevolle verwerkingstyd bespaar, en verseker dat die hele stelsel vinniger kan
reageer.
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Flight control system for an autonomous parafoilVan der Kolf, Gideon 12 1900 (has links)
Thesis (MScEng)-- Stellenbosch University, 2013. / ENGLISH ABSTRACT: This thesis presents the development of a flight control system (FCS) for an unmanned,
unpowered parafoil and the integration with an existing parafoil system in collaboration with
a team at the University of Cape Town (UCT). The main goal of the FCS is to autonomously
guide the parafoil from an arbitrary deployment position to a desired landing target. A nonlinear
8 degrees of freedom (8-DOF) parafoil model by C. Redelinghuys is incorporated into a
MATLAB Simulink simulation environment. The non-linear model is numerically linearised
and modal decomposition techniques are used to analyse the natural modes of motion. All
modes are determined to be stable but a poorly damped lateral payload relative twist mode
is present which causes large payload yaw oscillations. The FCS is divided into stability
augmentation, control and guidance subcomponents. Stability augmentation is proposed in
the form of a yaw rate damper which provides artificial damping for the oscillatory payload
twist mode. For control, a yaw rate controller is designed with the aim of a fast response
while not exciting the payload twist oscillation. Subsequently, an existing guidance method
is implemented for path following. Autonomous path planning and mission control logic is
created, including an energy management (EM) method to eliminate excess height and a
terminal guidance (TG) phase. The TG phase is the final turn before landing and is the
last chance to influence landing accuracy. A TG algorithm is implemented which generates
an optimal final turn and can be replanned en route to compensate for unknown wind
and other disturbances. The FCS is implemented on existing avionics, integrated with the
parafoil system and verified with hardware in the loop (HIL) simulations. Flight tests are
presented but are limited to remote control (RC) tests that verify the integration of the
avionics and the parafoil system and test preliminary FCS components. / AFRIKAANSE OPSOMMING: Hierdie tesis dra die ontwikkeling voor van ‘n vlug-beheerstelsel (VBS) vir ’n onbemande,
onaangedrewe valskerm-sweeftuig (parafoil), asook die integrasie daarvan met ’n bestaande
stelsel. Die projek is in samewerking met ’n span van die Universiteit van Kaapstad (UCT)
uitgevoer. Die VBS se hoof doel is om die sweeftuig outonoom vanaf ’n arbitrêre beginpunt
na ’n gewensde landingsteiken te lei. ’n Nie-lineêre 8 grade van vryheid sweeftuig model deur
C. Redelinghuys is in die MATLAB Simulink omgewing geïnkorporeer. Die nie-lineêre model
is numeries gelineariseer om ’n lineêre model te verkry, waarna die natuurlike gedrag van die
tuig geanaliseer is. ’n Swak gedempte laterale draai ossillasie van die loonvrag is geïdentifiseer.
Die VBS is opgedeel in stabiliteitstoevoeging, beheer en leiding. ’n Giertempo-demper
(yaw rate damper) is as stabiliteitstoevoeging om die loonvrag ossillasie kunsmatig te demp,
voorgestel. ’n Giertempo-beheerder is ontwerp met die klem op ’n vinnige reaksie terwyl
die opwekking van die loonvrag ossillasie terselfdetyd verhoed word. Daarna is ’n bestaande
metode vir trajekvolging geïmplementeer. Outonome padbeplanning en oorhoofse vlugplan
logika is ontwikkel, insluitend ’n energie-bestuur (EB) metode, om van oortollige hoogte
ontslae te raak, asook ’n terminale leiding (TL) metode. Die TL fase verwys na die finale
draai voor landing en is die laaste kans om die landingsakkuraatheid te beïnvloed. ’n Bestaande
TL algoritme is geïmplementeer wat ’n optimale trajek genereer en in staat is om
vir wind en ander versteurings te kompenseer deur die trajek deurgaans te herbeplan. Die
VBS is op bestaande avionika geïmplementeer, met die sweeftuigstelsel geïntegreer en met
behulp van hardeware in die lus (HIL) simulasies geverifieer. Vlugtoetse is voorgedra, maar
is egter beperk tot radio beheer vlugte wat die korrekte integrasie van die avionika en die
voertuig toets, asook ’n beperkte aantal voormalige VBS toetse.
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Development of a data collection system for small Unmanned Aerial Vehicles (UAVs)Zhou, Yan January 2011 (has links)
Dissertation (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2011 / This paper presents the development of a data collection system for a small unmanned
Aerial Vehicle (UAV) flight. The following three facets comprise of a UAV system: (1) a UAV
aircraft; (2) onboard avionics; and (3) a ground control station subsystem (Taha et al.,
2010:1). In this project, the UAV aircraft is based on the low-cost autonomous quad-rotator
system named “Arducopter Quad”, where the onboard avionic system utilizes both an
ArduPilot Mega (APM) on-board controller and IMU sensor shield, while the “Mission
Planner” software operates as GCS software to gather essential flight data (Xiang & Tian,
2011:176). The approach provides the UAV system structure and both hardware and
software with a small UAV data collection system, which is examined throughout the study.
And introduce the concept of Arducopter dynamics for better understanding with its flight
control.
The study also considers the communication process between the UAV and the ground
control station. The radio wave is an important aspect in the UAV data collection system
(Austin, 2010:143). The literature review introduced the basis of the radio wave in respect of
its travelling speed, and its characteristics of propagation, including how different frequencies
will affect radio wave propagation.
The aim of this project was to develop a platform for a small UAV real-time data collection
system. The pendulum system was involved to simulate the “Roll” movement of the small
UAV, while real-time IMU sensor data was successfully collected at ground control station
(GCS), both serial communication and wireless communication, which was applied in the
data collection process. The microwave generator interference test proves that the 2.4 GHz
XBee module is capable of establishing reliable indoor communication between the APM
controller and the GCS.
The work of this project is towards development of additional health monitoring technology to
prevent the safety issue of the small UAV. The data collection system can be used as basis
for the future research of real-time health monitoring for various small UAVs.
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EVALUATING UNMANNED AIRCRAFT SYSTEM PHOTOGRAMMETRY FOR COASTAL FLORIDA EVERGLADES RESTORATION AND MANAGEMENTUnknown Date (has links)
The Florida Everglades ecosystem is experiencing increasing threats from anthropogenic modification of water flow, spread of invasive species, sea level rise (SLR), and more frequent and/or intense hurricanes. Restoration efforts aimed at rehabilitating these ongoing and future disturbances are currently underway through the implementation of the Comprehensive Everglades Restoration Plan (CERP). Efficacy of these restoration activities can be further improved with accurate and site-specific information on the current state of the coastal wetland habitats. In order to produce such assessments, digital datasets of the appropriate accuracy and scale are needed. These datasets include orthoimagery to delineate wetland areas and map vegetation cover as well as accurate 3-dimensional (3-D) models to characterize hydrology, physiochemistry, and habitat vulnerability. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection
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Reconfigurable Aerial Computing System: Design and DevelopmentGu, Yixin 08 1900 (has links)
In situations where information infrastructure is destroyed or not available, on-demand information infrastructure is pivotal for the success of rescue missions. In this paper, a drone-carried on-demand information infrastructure for long-distance WiFi transmission system is developed. It can be used in the areas including emergency response, public event, and battlefield. In years development, the Drone WIFI System has developed from single-CPU platform, twin-CPU platform, Atmega2560 platform to NVIDIA Jetson TX2 platform. By the upgrade of the platform, the hardware shows more and more reliable and higher performance which make the application of the platform more and more exciting. The latest TX2 platform can provide real time and thermal video transmission, also application of deep learning of object recognition and target tracing. All these up-to-date technology brings more application scenarios to the system. Therefore, the system can serve more people in more scenarios.
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Design and Evaluation of Geometric Nonlinearities using Joined-Wing SensorCraft Flight Test ArticleGarnand-Royo, Jeffrey Samuel 14 June 2013 (has links)
The Boeing Joined-Wing SenorCraft is a novel aircraft design that has many potential benefits, especially for surveillance missions. However, computational studies have shown the potential for nonlinear structural responses in the joined-wing configuration due to aerodynamic loading that could result in aft wing buckling. The design, construction, and flight testing of a 1/9th scale, aeroelastically tuned model of the Joined-Wing SensorCraft has been the subject of an ongoing international collaboration aimed at experimentally demonstrating the nonlinear aeroelastic response in flight. To accurately measure and capture the configuration\'s potential for structural nonlinearity, the test article must exhibit equivalent structural flexibility and be designed to meet airworthiness standards. Previous work has demonstrated airworthiness through the successful flight of a Geometrically Scaled Remotely Piloted Vehicle. The work presented in this thesis involves evaluation of an aeroelastically tuned design through ground-based experimentation. The result of these experimental investigations has led to the conclusion that a full redesign of the forward and aft wings must be completed to demonstrate sufficient geometric nonlinearity for the follow-on Aeorelastically Tuned Remotely Piloted Vehicle. This thesis also presents flight test plans for the aeroelastically tuned RPV. / Master of Science
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