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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.
371

Enhanced communication support between control room and field operation : Human communication and interaction

Berg, Håkon Nergaard January 2007 (has links)
Communication between the field operator and the control room operator is vital for successful operation in the process industry. By reviewing models for human cognition and interpersonal communication and collaboration together with appropriate ~technology, concepts for enhancing the field operator/control room operator communication are developed. These concepts constitutes the basis for design and implementation of a working prototype. The prototype is utilizing a mobile device with wireless networking abilities.Evaluation of the concepts concludes that they most likely will enhance communication and decrease erroneous decisions because of higher system awareness and better mental models. This is achieved by introducing data to an operator from the system context of the other operator. The prototype also increases the communication abilities by allowing the operators to interact with each other through pointing and drawing.
372

Motion Analysis : Model Based Head Pose Estimation of Infants

Fernandez Cuesta, Roald January 2010 (has links)
This thesis presents a method for performing tracking and estimation of head position and orientation by means of template based particle filtering. The implementation is designed to withstand high levels of occlusion and noise, and allow for system dynamics to be accounted for. To accelerate the computation, GPGPU techniques are used to enable the GPU to function a co-processor, resulting in real-time performance. A method is devised for dynamic creation of feature points used in the particle filter. Furthermore, the graphics pipeline is used to overlay and visualize the tracking, as well as play a key role in the dynamic template functionality. Finally, a benchmarking system is suggested and developed for carrying out controlled evaluation of tracking methods in general.
373

Autonomous Bicycle

Brekke, Snorre Eskeland January 2010 (has links)
The autonomous bike was conceived by Jens G. Balchen back in the eighties, and later picked up by Amund Skavhaug. The idea of a two-wheeled, self-powered, yet riderless bike has since been pursued intermittently over the years. Audun S{o}lvberg was the last person working on the project in 2007, making large headway towards the final goal of the bike: An outdoor ride, preformed by a riderless bicycle.The same goal is shared by this thesis; to make the bike work as intended and get the bicycle running outside. Additionally, as it would be naive to assume that this work would leave the bike in perfect condition, the thesis focuses on documenting issues that are left unfixed upon completion. Unfortunately, a fully functional, outdoor demonstration was not achieved, but half of the battle was won: Two of the three motors residing on the bike can be fully controlled by an external device.At the start of the work, the instrumentation system was mostly completed. A computer, running a QNX Neutrino Operating System, interfacing with potmeters, motors, Inertial Measurement Units and a GPS where available, mounted on the bike. Drivers communicating with the hardware was already written, and a Simulink model, meant to control the bike had been developed. However, the motherboard was in need of replacement, and the Simulink model was not finalized or even tested. The system was also lacking wireless networking capabilities.Yet, at the onset of the thesis, it was believed that the project was very close to reaching its ultimate goal.As the work progressed, several issues became apparent, emerging along with problems being solved. The motherboard was replaced with a motherboard{}, implicitly requiring a new hard drive to be installed. The OS was upgraded from version 6.3.0 to 6.4.1, to bring it up to date and as a requirement for some of the motherboard hardware. All of the device drivers where modified to work without their counterpart hardware connected, easing development of the Simulink model. The model was shown to be unreliable, but the hardware interface subsystem was completed and tested to allow for easy integration in separate projects. To demonstrate the capabilities of subsystem, a Bike Demo model was created, allowing the steer and pendulum to be controlled by the used of the bike accelerometer, using orientation data as reference. The intent was for the demo to serve as a control system for an outdoor ride. Ultimately the motor controller card was found to be incompatible with the propulsion motor, unable to deliver sufficient current. At the time of discovery, too little time reminded for the problem to be rectified. A demonstration of control system however, was successfully concluded.An attempt to bring wireless networking to the bike failed. Arguably too much time was spent making USB Wifi devices working with the QNX OS, when easier alternatives could perhaps have solved the problem earlier.The thesis has a large focus on the work ahead, as the system is complex and unreliable by its very nature. All known issues are detailed and summarized, and the various chapters describing hardware and software have been outlined in an attempt to serve as a go-to reference for students taking on the autonomous bike project in the future.
374

Hardware Implementation of a Time Management Unit (TMU)

Søvik, Stian Juul January 2010 (has links)
This thesis describes the implementation of a Time Management Unit (TMU) in hardware as specified by Gregertsen and Skavhaug, the specification and implementation of several improvements to the proposed specification, and the creation of a software framework to enable use of the module in a convenient way. A set of thorough automatic functional tests are also described and provided. The performance of the module is assessed and discussed. A user description similar to the AVR32 UC3 datasheets is also created.The TMU has been implemented as a hardware module on the peripheral bus (APB) on the AVR32 UC3 microcontroller, which makes it easy to develop and test stand-alone, and simple to integrate into future UC3 microcontrollers. Also, as the APB interface of the AMBA standard is an open standard used by several System-on-a-chip (SoC) designs, the module can be implemented on other microcontrollers with very low effort.The final product makes it possible to measure and control the execution time of tasks with high precision and low overhead. It supports atomic swapping of registers in a manner closely related to a context switch.Gregertsen and Skavhaugs’s research in implementing support for the Ada language and run-time environment on the UC3 microcontroller will benefit directly from this project, as the system relies on the hardware support provided by the TMU. Also, as the project can be used in proving that hardware support of execution time monitoring may allow for new ways of ensuring schedulability in real-time systems, it can possibly be a part of a new direction in real-time research.
375

Condition Monitoring : Based on "black-box"- and First Principal Models

Borgan, Tom-Rune January 2011 (has links)
Summary and conclusionsThis master thesis investigates Principal Component Analysis (PCA) methods used in the field of Early Fault and Disturbance Detection (EFDD). Statoil and ABB have in collaboration developed an application for EFDD that among others consist of PCA methods. The applications are used to run condition monitoring on oil- and gas processes, and are a software prototype currently being tested in Statoil. To make the method more robust and convincing to the operators it is desirable to improve the application.This thesis will focus on the Principal Component Analysis (PCA) method and some extension to it based on Model Based PCA (MBPCA). The PCA in its simplest form have some severe restrictions due to linear and stationary data. The motivation will therefore be to see how PCA and extension based on MBPCA and Nonlinear PCA (NLPCA) methods operates when used on non-linear data. For the PCA to describe a process adequately a certain amount of data is required. In the industry the process is often sort of instrumentation. The next motivation would be to investigate if lack of instrumentation could be replaced by some estimates and then approve the ability for the PCA analysis. Another issue concerning instrumentation is the use of virtual tags. Virtual tags are mathematical functions based on already available measurements. The idea is based on process insight. If we know the process well and the cause of nonlinearities some additional nonlinear functions could be incorporated to increase the performance of the PCA method. To verify the factors mention above some of the methods would use data from a heat exchanger – and Centrifugal pump process, and some using only one of the processes.The conclusion from the work is as follows: Based on the simulations preformed it’s evident that using MBPCA do improve the PCA method for fault detection, even if the model is not entirely correct to the real process. When it comes to using virtual tags the simulations on centrifugal pump increased the performance of the PCA method. NLPCA here based on Autoassociative Neural Networks did not perform as well as MBPCA but the method is harder to tune and therefore it would be wrong to brush aside this method. The improvement of using estimates for missing measurement gave small improvement.
376

EPP-basert protesemodell / EPP-based arm prosthesis

Solberg, Ranveig January 2011 (has links)
Oppgaven er en fortsettelse av tidligere arbeid med å utvikle en EPPbasertprotsese med to frihetsgrader til en ung dysmelipasient som hartransversell armdysmeli med en rudimenter nger. Denne ngeren skalbrukes til å styre protesen. Det er gjort et litteratursøk for å kartleggemetoder og utfordringer for reguleringsteknisk analyse av epp- og telemanipulatorsystemer,og satt opp et sett kriterier som er viktige å ta hensyntil under realisering av systemet. Det er beskrevet et programstruktur,som siden er realisert på to AVR Buttery, en for hver frihetsgrad. Disseer koblet til en protesemodell og en proksimal styringsmodul tilpasset ennormal hånd for testing av konseptet.
377

Autonomous Bicycle : The First Self Balanced Ride

Ånnestad, Dag Christian January 2011 (has links)
The idea of an autonomous bicycle originates from Jens G. Balchen who wanted to make an unmanned autonomous bicycle. The idea was picked up by Amund Skavhaug who extended the idea with the concept of using an inverted pendulum to simulate a leaning rider. The previous attempts to develop a bicycle capable of performing an autonomous ride has so far all ended in failure. The main reason for the Department of Engineering Cybernetics is to develop such a bicycle is for use in recruitment and motivation of students. The main goal of this thesis is to develop a bicycle that after the implementation of a suitable control is capable of performing an autonomous ride.The goal of this thesis is to create a controller making the bicycle capable of performing the first self balanced ride. The focus is not on implementing the most advanced controller but creating a system actually capable of performing this first ride. An equally important focus is that the framework delivered at the end of this thesis is capable of handling the further development towards a fully autonomous bicycle.The author has during this thesis performed the additions needed in order to be able to implement a self balancing controller. The parameters of the real bicycle were measured and used to create a simulation environment of the bicycle in Simulink. Several controllers were simulated in Simulink, before a controller were implemented on the physical bicycle.The physical bicycle delivered as a part of this thesis consists of a fully functional framework both capable and ready for the further development. A self balancing controller is implemented on the bicycle and the bicycle has performed it's first self balance ride.
378

Leak Detection in Pipelines by the use of State and Parameter Estimation / Leak Detection in Pipelines by the use of State and Parameter Estimation

Oven, Sindre January 2014 (has links)
A model based estimation process is implemented in simulation of a transmissionline for the purpose of leak detection. The model has one inlet, one branch and twooutlets. The objective of this thesis is aimed at determining, through simulation results,the effectiveness of the Kalman Filter for leak detection in a pipeline network.Water distribution systems often contain a large amount of unknown losses. Themagnitude of the water loss range from 10 to over 50 percent of the total waterpumped. Water leaks and losses lead to an unnecessary increase in energy usedto pump water to users, which means higher costs for the providers and thus thecustomers. Our increasing population and the necessity and limited availability ofwater will, and are already causing problems, so it is obvious that more controlefforts need to be implemented on these systems. Moreover, leaks that are not consideredto be major faults tend to go unnoticed, which in total add up to a lot ofwater loss.The work done in this thesis may also be relevant for the petroleum industry, astransportation of oil and gas also face many of the same problems as the waterdistribution industry. One should also note that the environmental impact of leaksin oil pipes are bigger than those in water pipes.The leak detection process used in this thesis is model based. A model of a transmissionline with a branch and two outlets is derived from two basic partial differentialequations describing mass and momentum balances for a hydraulic transmission line.Simulations are run , and when the system is in its steady state, a leak is introduced.Flow and pressure at all three extremes are used as inputs to the Kalman Filter.The likelyhood of two leaks occuring simultaneously is low, so only one leak will beexpected at a time.Localization of the leaks are not studied, only the detecton and the magnitude.It is shown that a Kalman Filter can be used as a detection method in this systemto a certain degree. The changes caused by the pressure change is noticable when aleak occurs in a large scale system, even if the leak is very small. The speed of theKalman Filter proved to be a problem area, as some of the estimated states useda long time to reach its final value. More satisfying results may be found throughmore rigorous testing, improvements in the model itself, and changes to the tuningparameters in the Kalman Filter.
379

UAV Path Planning for Ice Intelligence Purposes using NLP

Grimsland, Lars Arne January 2012 (has links)
As the oil and shipping industry are interested in operating in arctic waters, the need for ice intelligence gathering is rising.The thesis describes the implentation and results of a path planning framework for an UAV used for ice intelligence purposes. THe framework produsces paths based on optimization of a non-linear problem, using the IPOPT library in C++.A model for information uncertainty is implemented, and optimal paths based on minimizing the total information uncertainty are compared to optimal paths based on minimizing distance between UAV and target. Both off line and offline path planning is tested with single and multiple targets.It was found that minimizing information uncertainty can work very well for path planning for ice berg surveillance, or for surveillance of a small search grid.Minimizing information uncertainty generally gave better results than minimizing distance between the UAV and given targets.The implementation should be made more robust, and interfaces towards other UAV sysmets has to be made before the path planning platform has any practical use.
380

Stabilizing Slug Control Using Subsea Choke Valve

Lieungh, Mats January 2012 (has links)
This thesis study the possibility of riser slugging control in oshore oil productionusing a subsea choke valve. A 5-state simplied model of a well-pipelinerisersystem is introduced and tted to a reference model in the ow simulatorOLGA. The models have two inputs, a subsea valve at the wellhead and a topsidevalve at the top of the riser. The eect the valves have on the behavior ofthe simplied model are tted to simulation data from the OLGA-model usingbifurcation diagrams.An input-output controllability analysis of the simplied model show thatanti-slug control using a subsea valve at the wellhead is more dicult than theconventional solution, which is to use the topside choke valve. This is conrmedby simulations on the simplied model using Hinfinity-controllers.Stabilizing control of the OLGA-model using the subsea valve was unsuccessful,despite testing dierent measurement combinations and control structures.A more promising solution for controlling riser slugging using a subsea valve istested in OLGA, where a subsea valve located near the base of the riser can keepthe system stable at riser slugging conditions. This is also seen in an experimenton a small scale ow lab.

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