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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.

Survey of SCADA systems and visualization of a real life process / Översikt över SCADA-system och visualisering av verklig process

Gomez Gomez, Jose Angel January 2002 (has links)
Most of the industrial plants has a control center where is installed a SCADA (Supervisory Control And Data Acquisition) application. At the moment, it exists a great offer of acquisition, supervision and control of software and the evolution of this software follows a triple tendency: intercommunication between applications, standardization of the communications with the field devices and adoption of the communication surroundings. The report is divided in two parts: In the first the reader can learn the basic ideas of SCADA system and find the most important SCADA software available today. InTouch 7.1 and WinCC have been studied in more depth because they are the most successful software. In the second part is described the visualization of a real life process, it is the visualization of a toy car factory allocated in Linköping?s University and how interconnected the visualization process with the PLC (Programmable Logic Controller). In the report also are described the basic components needed to realize the visualization of any process involving PLCs.

Ett mät- och reglersystem för temperaturkompensering

Löwendahl, Jonas, Wegman, Micael January 2002 (has links)
An automatic control system for calibration of pressure indicators has been constructed. This control system can be used as a complement to the calibration system located at AerotechTelub, division MainPartner, in Linköping. The calibration system used today contains some not wanted pressure changes, which is compensated by hand today. The new system presented in this report automates the calibrating process and simplifies the calibration. Suitable hardware as motor, controls card and so on have been found and software in the form of Visual Basic program has been developed. The solution presented in this thesis satisfies the goals that have been presented in the goal description. To achieve a more complete automatic calibration system there are some further improvements yet to be done.

En simuleringsmiljö för distribuerad navigering / A simulation environment for distributed navigation

Färnemyhr, Rickard January 2002 (has links)
This master thesis studies distributed navigation which isa function implemented in a future network based combat information system to improve the accuracy in navigation for combat vehicles in a mechanized battalion, above all in the event of loss of GPS. In the event of loss of the GPS the vehicles obtain dead reckoning performance through the backup system that consists of an odometer and a magnetic compass. Dead reckoning means a drift in the position that makes the accuracy in the navigation worse. The distributed navigation function uses position and navigation data with measurements between the vehicles to estimate the errors and uncertainties in positions, which are used to improve the accuracy in position for the vehicles. To investigate and demonstrate distributed navigation, a simulation environment has been produced in Matlab. The environment is general so different navigation systems can be used and studied and also dynamical so a further development is possible. The simulation environment has been used to investigate and evaluate an implementation of distributed navigation. The implementation has been made using a central filter where fusion takes place of all navigation data and measurements. This filter has been realized with help of Kalman filter theory, in which all vehicles are put together in a state space model. Simulations have been performed for different scenarios and the result of these show that the drift in position is avoided.

Utveckling och implementering av ett audiopejlsystem baserat på tidsdifferensmätning / Development and implementation of an acoustic direction- and location-finding system using time difference of arrival

Wikström, Maria January 2002 (has links)
The use of spread spectrum signals has increased dramatically in military applications. Finding methods for detecting and positioning of these signals have become interesting research areas for signal intelligence purposes. One method is to measure the time difference of arrival (TDOA) that occurs when two receivers are synchronous and spatially separated. Based on the TDOA-technique an audio-demonstrator has been developed and implemented. This report describes the theory for how sound received in microphones can be used to extract information about the transmitter’s position from the measured time difference. The technique has been implemented and tested in a non-silencing room where sound from a loudspeaker has been recorded into MATLAB through the use of microphones. By correlating the received signals, an estimation of the time difference can be made. A hyperbolic function represents all possible transmitter positions for the given time difference. With three of more receivers a single position can be estimated. With an accuracy within a couple of hundreds of a degree, a direction can be estimated with simulated signals for a given SNR (usually 25dB) or a position within a few centimetres when the transmitter is a couple of meters away. Tests with real audio signals show less satisfying results. The position can at best be estimated with an accuracy of 5% of the distance to the receiver when the microphones are spread out 0.7m apart. The performance of the audio-demonstrator can be improved by using better methods for finding the points of intersection between hyperbolas and by weighting the estimated time differences.

Integration av simuleringsmodeller för bränslesystemet i JAS 39 Gripen / Integration of Simulation Models for the Fuel System in JAS 39 Gripen

Lindgren, Michael January 2002 (has links)
In this final thesis two simulation models have been integrated. The simulation models are models of JAS 39 Gripen’s fuel system, software and hardware. The time consuming and costly work to develop software has made the department of fuel system to build two models in Xmath/Systembuild. The software model also simplifies the comprehension of how the software in the control computer of the fuel system works. Before the final thesis was done the software and hardware models were used separately and for different purposes. The software model wasused for verification and validation, and the hardware model for the system simulator. Because of the complex software it was a requirement to be able to simulate the software and hardware when they were connected, which would make it possible to study the different control signals generated by the software. To do that an interface between the user and the simulation model was created because it takes too much time to set all the inputs to the simulations model. The final thesis was assumed to deal only with an upgrading of the software model. The models have been connected and a user’s interface has been created with help of the program language Mathscript, which is a part of Xmath. A user’s guide is written so the user can simulate without experience of Xmath/Systembuild. With the connected models the user can now efficiently simulate and the result can be saved for later usage. The user can also simulate predefined missions from Saabs system simulator.

Gruppmålföljning av markobjekt / Group Tracking of Ground Targets

Solli, Johanna January 2002 (has links)
This Masters Thesis considers tracking of ground targets. Since ground targets often are difficult to detect with sensors a track is easily lost in ground target tracking. The main question in this thesis is whether information on close targets and observations of them can be used to make the tracking more reliable. An algorithm using Kalman filters and JPDA-association to create a group track for vehicles travelling together has been implemented in Matlab. Using the state of the centre of the group the state of a vehicle in the group can be updated. The result of updating vehicles states with the state of the centre of the group is that the relative decrease in lost tracks is improved with up to 53 % in the studied case.

Algoritmer för objektdetektering i SAR och IR-bilder / Algorithms for detection of objects in SAR and IR-images

Ahlström, Linus January 2003 (has links)
The first part of the thesis consists of a brief introduction to the general principles of target detection and the sensor-systems used. In the following part there is a theoretical description of the algorithms this thesis focuses on. The detection algorithms described in this paper are called Cell Average, Ordered Statistics, 2parameter and Gammadetector. Two different discriminators called Extended Fractal Features and Quadratic Gamma Discriminator are also described. The algorithms are tested on three different types of data, simulated SAR-pictures, authentic SAR-targets and IR-pictures. The last part account for the results, both those achieved with pictures and those results achieved when doing statistical tests, in this case MonteCarlo- simulations and Reciever Operating Characteristics-curves. The results show that the Gamma- detector and the QGD-algorithm perform best on the tests done in this thesis.

Quality of Service i IP-nätverk / Quality of Service in IP Networks

Ahlin, Karl January 2003 (has links)
The original promise behind the Internet Protocol was to deliver data from a sender to the receiver using a best-effort approach. This means that the protocol makes no guarantees except that it will try to deliver the data to the destination. If some problem occurs the packet may be discarded by the network without any notice. No guarantees are made regarding the time it takes to deliver the data, the rate at which data will be delivered or if data is delivered in the same order it was sent. The best-effort approach is arguably the reason behind the success of the Internet Protocol and is what makes IP scalable to networks the size of the Internet. However, this approach is also a problem for network operators who want to offer better quality of service to some of their customers. This master thesis will discuss some of the theories behind the implementation of quality of service schemes in an IP network and also provide an example of how to implement it in an existing network.

Modellering och reglering av drivenheter i gaffeltruck / Modelling and control of the drive units in a forklift

Arnsby, Mattias, Tägtström, Bo January 2003 (has links)
To enable the enhancement of the driver's environment in a forklift, an alternative form of steering has been evaluated. An earlier concept with a combined driving and steering wheel has been exchanged to a concept with two driving wheels. A link wheel has replaced the combined driving and steering wheel. The steering is done through differentiation of the velocities of the two driving wheels. The scope of this master thesis is to create a simulation model, create a control program and to evaluate the concept of two driving wheels. The simulation model was created in Matlab/Simulink with the aid of enclosed functions written in C. The model is constructed so that the same control program can be used in the model as well as in the physical forklift prototype, which the model is based on. Validation of the simulation model shows that the model is in accordance with reality in a satisfactory manner. The control program is a compromise between a gentle behaviour of the forklift and a quick response to the driver's steering commands. Evaluation of the concept shows that steering through differentiation of the wheel velocities is possible although there are some deficiencies. The two main deficiencies are that, when driving slowly, the link wheel will affect the steering of the forklift in a negative manner, and that there are limitations regarding motor power.

Modellering och simulering av tryckreglersystemet till en kärnkraftsreaktor / Modelling and simulation of the pressure control system in a nuclear power plant

Rosell, Daniel January 2003 (has links)
Under ventilprov vid kärnkraftverket Oskarshamnsverket 3 har oscillationsfenomen detekterats vid vissa driftlägen, främst i samband med stängning av någon av högtrycksreglerventilerna som reglerar ångflödet ut från reaktortanken. Syftet med detta examensarbete är att förklara uppkomsten av dessa oscillationer. För att kunna analysera problemet har en modell över reaktor och tryckregulator tagits fram. Detta har gjorts dels med hjälp av befintlig systemdokumentation och dels genom att skatta modeller av olika delar av systemet. Det har visat sig att det går att få fram en modell som skattar reaktortrycket ganska väl med ångflöde och neutronflöde som insignaler. En tidigare beskrivning av ångflöde för olika ventilöppningsgrader har visat sig vara felaktig och därför har en ny ångflödesfunktion tagits fram. Vid simuleringar med den modell som har byggts upp över tryckreglersystemet har oscillationsfenomenet kunnat påvisas. Tryckregulatorn syftar till att hålla reaktortrycket konstant genom att variera ångflödet ut från reaktorn. Detta görs genom att variera ventilernas öppningsgrad. Förhållandet mellan öppningsgrad och ångflöde är dock inte linjärt. Meningen är att detta ska kompenseras i reglerservomotorn som ska reglera ventilerna så att ångflödet motsvarar det beordrade ångflödet från regulatorn. Denna linjärisering bygger dock på det felaktiga sambandet mellan ventilöppningsgrad och ångflöde. Vid stängning av en högtrycksreglerventil kommer signalen från tryckregulatorn att förstärkas jämfört med fallet med samtliga ventiler öppna, något som med stor sannolikhet leder till uppkomsten av självsvängningar. I rapporten ges två förslag till lösningar på självsvängningsproblemet. Om man kan få fram en bra bild av det olinjära sambandet mellan regulatorns signal och ångflödet borde detta kunna kompenseras i regulatorn så att man åter får ett linjärt samband. Ett annat alternativ är att byta ut de kurvskivor som nu används för linjärisering i reglerservomotorerna så att man får ett linjärt samband mellan regulatorns beordrade ångflöde och det verkliga ångflödet.

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