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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.
71

Regulering og optimalisering av Shell Eco-maraton kjøretøy / Control and optimization of Shell Eco-marathon vehicle

Øverby, Jardar Sølna January 2011 (has links)
Å bygge en bil som kan kjøre tusen kilometer på energien i en eneste liter bensin; er ingeniørkunst. Når tusenvis av Europas ypperste studenter innen teknologi og ingeniørvitenskap hvert år møtes i konkurransen Shell Eco-marathon, utfordres skillet mellom hva som oppfattes som mulige og umulige. Kreativitet og respektløs nytenkning utfoldes når morgendagens teknologer får muligheten til å følge nysgjerrigheten på jakt etter nye å bedre teknologiske løsninger for morgendagens samferdsel. Dette er hvordan det har vært å oppleve og være deltager i NTNU sitt fjerde bidrag til Shell Eco-marathon. Motivasjonen for prosjektet har med andre ord vært stor.Arkitekturen og mange av modulene som ble brukt i kontrollsystemet i 2011-versjonen av DNV Fuel Fighter, ble arvet fra 2010-versjonen. Det ble i 2010 lagt ned et solid stykke arbeid i lage et modulbasert og fleksibelt kontrollsystem til bilen. Det lot seg derfor gjøre å kombinere en videreutvikling av noen av fjorårets løsninger, med også å introdusere helt ny funksjonalitet. Hver modul sin videre inndeling i en spesialmodul, og en universalmodul som er lik for alle nodene i det CAN-baserte nettverket har fortsatt fungert utmerket.Av de nyvinningene som faller inn under denne rapporten, nevnes først og fremst arbeidet med utvikling av et hybridsystem for å kunne bruke en modul av superkondensatore til å øke energiutnyttelsen i den elektriske delen av framdriftssystemet. Det er da først og fremst muligheten til å kunne tilbakeføre noe av bevegelsesenergien fra bilen til kondensatorene under nedbremsing med elektromotoren, som har vært det viktigste formålet. Slik kan energien så lagres til videre bruk under påfølgende akselerasjon. Dette systemet er både simulert og produsert, men ble dessverre ikke tatt i bruk under faktiske konkurransen. For senere studenter ligger det flere muligheter her til å få tatt dette systemet ordentlig i bruk.Videre nevnes det hardware-endringer for å bedre kontrollen over vifta som sørger for luftgjennomstrømning i den hydrogenbaserte brenselcella. Dette ga bedre kontroll over arbeidstemperaturen i cella. I tillegg en ny modul for å sikre gode målinger av flere viktige tilstander i systemet lagt til. Det medførte at det for første gang ble gjennomført målinger av strømmen i koblingene mellom brenselcelle og motorkontroller.Årets største utfordring har imidlertid vært motoren. Uforutsette svakheter i designet av motoren, førte til store problemer å komme opp i store nok hastigheter. Årsaken var at en for høy tilbakeindusert spenning fra motoren gjorde at spenningsnivået som var tilgjengelig fra brenselcella ikke strakk til når turtallet vokste. Dette problemet ble ikke beskrevet i noen rapport fra 2010. I samarbeid med SmartMotor, som en av flere viktige partnere for prosjektet, fikk selv denne utfordringen en løsning. Denne løsningen innebar å øke luftgapet i motoren slik at koblingen mellom permanentmagnetene og statorviklingene ble svakere. Dette er imidlertid en løsning som kompromiterer virkningsgraden i motoren. Hvor mye redusert virkningsgrad denne tilpasningen førte til ble aldri forsøkt målt. Ved en eventuell gjenbruk av motoren, må dette problemet få en permanent løsning.Som kronen på verket ble laget til slutt belønnet med to gjeve priser etter et godt gjennomført løp på konkurransens siste dag. Det ble andreplass i klassen, og pris for beste mediehåndtering.
72

Control of a multifunction Arm Prosthesis Model

Bersvendsen, Jørn January 2011 (has links)
In this thesis a working control system for a 7 degrees of freedom hand prosthesis model controlled by electromyographic and accelerometer signals has been developed.The complete system consists of a wireless EMG and accelerometer measurement system, two National Instruments data acquisition modules, a desktop computer, a Lego Mindstorms NXT brick and a hand model with 7 motorized degrees of freedom.The controller is based on pattern recognition and signal classification.Several different EMG features for this purpose are presented and implemented.Two different linear classifiers were used and their performance studied.The LabVIEW software platform was used for both the computer and the NXT.The developed software has a modular design, facilitating future development and extension.Its design and implementation are presented and discussed.
73

Visualisering av store mengder data i brannvarslingssystem / Visualization of large amounts of data in fire alarm systems

Nilsson, Gaute January 2011 (has links)
På broen i et moderne cruise-skip kryr det av teknologiske innretninger for styring av forskjellige tekniske detaljer ved båten. Støynivået skal være lavt og utstyr som genererer unødvendig støy skal ikke forekomme. Derfor foretrekkes visuelle presentasjonssystemer som er rasjonelle og som ikke stresser mannskapet.Mesteparten av båtens tekniske systemer presenterer en helhetlig oversikt over systemet via en skjerm, og muligens et pekredskap/tastatur oppe på broen.Ettersom moderne skip i dag er meget høyteknologiske resulterer dette i et stort antall systemer med tilhørende informasjonspresentasjonssystemer som alle krever oppmerksomhet fra tid til annen.Autronica som ledene aktør innenfor branndeteksjon ønsker å se nærmere på alternative måter å skaffe en rask og helhetlig oversikt over deres system. Oppgaven tar for seg et eksperiment hvor det studeres om det er mulig å presentere store datamengder ved å påtrykke spesielle parametere til et komplekst dynamisk system.
74

A Modular Software and Hardware Framework with Application to Unmanned Autonomous Systems : Interacting Modules, Error Detection and Hardware Design

Skøien, Kristoffer Rist January 2011 (has links)
The Department of Engineering Cybernetics at the Norwegian University of Science andTechnology established the Unmanned Vehicle Laboratory fall 2010. The goal is to havestudents develop a fully functional autonomous aerial vehicle over time as part of projects and master’s theses. A range of projects were carried out fall 2010, among others the report General Platform for Unmanned Autonomous Systems was written on the topic of hardware, operating systems and peripheral interfacing.This master’s thesis continues where the previous report left suggestions for further work, and covers the topics of a software framework, sensor error detection, actuator and sensor interfacing, that is now part of the autonomous flight system.A highly modular software framework has been constructed, applicable far beyond theunmanned vehicle domain. Due to the high level of encapsulation and modularity it isespecially valuable in projects where there is a high mobility of the workforce, such as student projects and theses. It acts as a middleware layer, with language independent, separately compilable modules, communicating with one another to achieve the desired functionality.To prevent unrealistic or erroneous sensor readings from spreading through the system, a software detection unit catches signal anomalies based on statistics and alerts subscribing modules. The algorithm has been interfaced into the software framework, and is applicable to numerous sensors.Hardware was designed, constructed and tested to handle sensor interfacing, power supply demands and real-time critical actions such as actuator control. The design is performed from an aerial vehicle application point of view, but general to such an extent that is usable in a wide range of autonomous crafts.The framework, filter and hardware are merged together and tested on an embedded system, verifying the system functionality with a feedback loop from measurements to actuators. Utilizing the previous work along with all three elements of this thesis, a fully functional system for vehicle control is achieved.
75

NAROM Mikro UAS / NAROM Micro UAS : Unmanned Aircraft System for Educational Use

Tokheim, Arve Jørgen Haugland January 2011 (has links)
This report presents the development of the NAROM UAS, an Unmanned Aircraft System for educational use by the Norwegian Centre of Space Related Education (NAROM). The NAROM UAS is a small, inexpensive and modular platform intended for technological courses. This UAS enables students to plan and carry out UAS operations while also flying their own experimental payloads.A Skywalker EPO airframe was successfully selected as the platform for the Unmanned Aerial Vehicle (UAV), providing a flight endurance of about one hour and a tested payload capacity of unit{550}{gram}. The NAROM UAV also holds an ArduPilot Mega autopilot (APM). The APM proved reliable and sturdy once correctly set up. A meteorological payload was also developed for the NAROM UAV, based on a CanSat kit. This payload includes pressure, temperature, and humidity sensors in combination with a GPS receiver. Spatial weather data was transmitted to a Ground Control Station (GCS) and recorded in real-time. Consistent weather pattern data was collected in flight although the full potential of this platform could only be fully demonstrated by a scientific weather mapping study; however, this proved to be outside the scope of this master thesis.
76

Robotisert tankrensesystem for fiskeyngeloppdrett / Robotic tank cleaning system for fish juvenile production

Braa, Håvard Lein January 2011 (has links)
Denne prosjektoppgaven beskriver utvikling og konstruksjon av en prototype av en autonom tankrenserobot for marin yngelproduksjon. Gjennom oppgaven har det blitt utviklet et nytt konsept og en prototype som viser mulighetene for et automatisk tankrensesystem. Det valgte konseptet baserer seg på en selvgående robot som kjører på tankens utside, med en magnetisk kobling til en rensepute på tankens innside. Gjennom et riktig forhold mellom masse og friksjonskrefter, kan prototypen både bevege på seg og henge fast på tanken. Ved bruk av permanentmagneter har dette latt seg løse. På grunn av riktig dimensjonering av krefter og tilpassede løsninger er det utviklet en farkost som kan traversere både tankens bunn og tankens vegger uten problemer. Det er utviklet et rensekonsept for å løsne avfallet fra den begrodde tanken, med minimale forstyrrelser av yngelen. Dette ble løst med et roterende magnetfelt gjennom tankveggen til en roterende rensepute på tankens innside. Praktiske tester i tank med vann og tørrfor viser at renseren løsner avfallet fra tankveggen, ved at det løses opp i vannet. Et konsept for utnyttelse av en enkelt robot for automatisert rens av flere tanker har blitt utviklet. Gjennom et egenutviklet brosystem kan dette løses. En prototype av et brosystem har blitt utviklet og testet på en enkelt tank. Resultatene viser at konseptet kan utvikles til et komplett tankrensesystem for en hel tankrigg. Systemet skal enkelt kunne installeres. Det har blitt løst ved å utvikle et grafisk brukergrensesnitt til en PC. Med trådløs dataoverføring til roboten, kan rensesystemet enkelt installeres. En operatør kan også overvåke robotens posisjon og status via brukergrensesnittet. Valg av sensorer på roboten har blitt gjort med tanke på å oppnå tilstrekkelig presisjon med en lav investeringskostnad. Gjennom kalibreringsrutiner og praktiske testing er sensorenes ytelser verifisert mot ønskede egenskaper. Det benyttede sensoroppsettet har tilstrekkelig nøyaktighet, liten fysisk utforming og er prisgunstig. Et fungerende posisjonerings- og navigasjonssystem er utviklet basert på angitte waypoints på tankene. Testkjøring med systemet har vist gode resultater. En posisjonsnøyaktighet på ca 2 cm er oppnådd for hele tankveggen. Dette er vurdert som godt nok for den gitte oppgaven. På tankbunnen ble ikke nøyaktigheten testet.I løpet av prosjektet er det utviklet elektronikk. Et design bestående av to kretskort er planlagt med tanke på stor fleksibilitet for fremtidig bruk. Elektronikken har vist gode egenskaper gjennom testing underveis i prosjektet. Målet med oppgaven var å utvikle et konsept og en tilstrekkelig utviklet prototype for et rensekonsept. Den utviklede prototypen har ikke de mekaniske egenskapene som trengs for å sikre stabilitet og robusthet i et ferdig produkt. Når vi ser på de valgte løsninger og oppnådd funksjonalitet opp mot den gitte oppgaven, er grunnlaget for et bra konsept og en produksjonsmodell lagt. Ved hjelp av utviklet teknologi vil et helautomatisk rensesystem fjerne dagens behov for manuell arbeidsinnsats i forbindelse med tankrensing.
77

Automatic Inspection of Cage Integrity with Underwater Vehicle

Jakobsen, Rolf Arne Hult January 2011 (has links)
This thesis is a preliminary study for the initiative to develop an autonomous AUV foruse in aquaculture. A micro-ROV is used to test the concept of inspecting net integrityin sh cages by analyzing video feed from a video camera. Software is developed, including an interactive GUI, thruster control, and the analysis algorithms. A lasermodule is also developed to measure the distance between the ROV and sh cage usingtwo laser line generators. The conclusion is that checking for net integrity with a camera and computer vision software is a viable option in a future AUV. The laser module works well, providing reliable distance measurements for the ROV.
78

Microcontroller based fluid flow and image control system for biochemical analysis

Kotsbak, Marius Bjørnstad January 2007 (has links)
Jarle Kotsbak started started the company Kotsbak Consulting to test an idea he had of a method of sequencing DNA material, that is reading the contents of the string of genes in a DNA. The method is supposed to be much faster and cheaper than the methods that exist today. For the analysis equipment there are a lot of parts that need to be developed, and the most important ones in the first phases of experimentation is given as problems for this thesis.The analysis is going to take place in a relatively small reaction chamber where chemicals need to be automatically added and heated to the correct temperature. Then a high resolution image is going to be captured using a small image chip similar to those found inside digital cameras. As these have varying real time requirements, it is not possible to control from a ordinary PC. A microcontroller is needed to do the low level controls. Control of the experiments should be possible to set up from a PC connected to the equipment using a USB (Universal Serial Port) 2.0 port, which is also going to transfer the images captured to the PC for image and data analysis.Atmel AVR32 microcontroller was suggested for use, and it was not found that any of the requirements was not in theory possible to solve using this microcontroller, so it was the one used in all parts. It was evaluated if it was best to program the microcontroller directly without an operating system, but it was found that using Linux, which the evaluation boards of the microcontroller was shipped with, had so many advantages over the small and uncertain advantages of programming the microcontroller directly. so Linux was used in all parts. As most of the needed drivers for Linux were new or unreleased, a lot of time was spent learning how to compile the Linux kernel with those patches and finding out how to use the undocumented parts of the drivers, as well as extending the drivers to support the hardware and specification needed.The heating controller worked quite well after getting the connection to the sensors working, including estimation of the temperature inside the reaction chamber, which is the temperature that is going to be controlled, but can not be measured directly. If needed it is possible to tune the controller better for stricter requirements or change to a model based controller if needed and the parameters in the model can be found, which turned out to be hard.A nice solution to the flow control was found using a stepping motor that is able to push the piston in a syringe containing one of the chemical mixes in exact amounts, controlled by an external stepping motor driver chip, which was easy to get working, connected using I2C. The solution was at least as good and much easier to implement than the one suggested in the assignment, using valves and pressure measurements to estimate the amount flowing.It was shown that image capture of the required resolution, i.e. 2048 x 1536 and possibility for much higher, was possible using Linux and the hardware support for transferring images from image chips in the AVR32 microcontroller using kernel modules. The problem is that it was only working sometimes, so a little more debugging of the possible hardware/ software reason for this to be resolved, but it seems like it is only a small problem and not caused by any limitation in software or hardware.It was attempted to get the USB part working without running an O/S on the microcontroller, but it did not succeed, partly because of incomplete documentation of the USB hardware module in the AVR32. Then the available driver systems for USB slave equipment under Linux was studied and it was found that gadgetfs seemed most promising to use. The driver did though first not load, just giving a stacktrace. In a newer version of the Linux version for the development board, it did though load and it seemed like it was working. Further development of this part was not done because of much delay in the other parts, and the fact that choosing Linux as platform, as well as the image being buffered in RAM, allows to use ethernet to transport the images during testing until later product development stages.Overall most of the parts have been accomplished according to the specifications, although there was not too detailed practical testing of each part because of much time spent on solving problems, and the fact that many complex parts were outlined to be solved during the project. Solving the small problems left as described at the corresponding discussion chapters should, with small modifications/customization, make the practical solutions found usable for future prototypes of the product or for more experiments.
79

Anti-Slug Control with Non-Linear State Estimation

Syre, Terese Vardenær January 2012 (has links)
In offshore production, the two-phase mixture of oil and gas is transported from the seabed oil wells to the surface facilities by pipelines and risers. The two-phase flow can have different flow regimes, where severe slugging is one undesirable flow regime and an effective solution is needed to prevent it. The recommended solution is active control of the top-side choke valve. Previously, controllability analysis is done of two-phase flow in a 4-state pipeline-riser model. This analyze concludes that the best way to control the choke valve is by using the subsea pressure measurement combined with topside flow measurement. However, the subsea pressure might be difficult to measure correctly because the pipeline is placed under tough conditions, hundredth or even thousands of meters under sea level. One possibility is to combine topside pressure with topside flow measurement and use for estimation of states or other sub-sea measurements that are normally not available. Simulation studies are done in MATLAB of different anti-slug control solutions. Linear Kalman filter, extended Kalman filter (EKF) and unscented Kalman filter (UKF) are used for state estimation and combined with controllers such as PI, LQR and MPC. The input to the system is flow rate of gas and liquid, and the nominal choke opening. The input disturbance to the process is change in the flow rate of gas and liquid imitating slug flow.As expected, when only topside measurements are used, because of the highly nonlinear system dynamics the linear Kalman filter fails in stabilizing the system. The EKF works good when the system has low input disturbance, while the UKF is the best nonlinear filter when the system has high input disturbance. However, when the nominal choke opening is increased, the UKF combined with a controller fails. The LQR controller combined with UKF shows slightly better results than the PI and MPC controller combined with the same filter for state estimation. There is also potential in using the high-gain observer in control strategies.
80

Motion Planning Framework for Industrial Manipulators using the Open Motion Planning Library (OMPL)

Barland, Martin January 2012 (has links)
Robotic manipulators are used in many different scenarios these days. If one of these manipulators is moved from one location to another it may require a total reprogramming of that manipulator because of the new environment the robot is working in. This is because the path planning and trajectory planning scheme which works in one environment might not be suitable in another. This text takes a look at how an intuitive and easy to use motion planning framework for finding paths in different static environments or scenarios can be made. The use of the Open Motion Planning Library has been used for the path planning and second-order cone programming solved by SeDuMi in Matlab has been used for finding the time-optimal trajectory.

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