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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.
1

Erfarenheter från utveckling av kvadratisk optimeringsalgoritm för prediktionsreglering

Ljung, Dennis, Das, Ruben, Isaksson, Johan, Yngve, Alexander, Sestorp, Adam, Söderén, Martin, Fast, Sebastian January 2015 (has links)
Denna kandidatrapport studerar en projektuppgift som har utförts av en grupp studenter på Linköpings universitet. Uppgiften har givits av en industridoktorand på Saab och härstammar från reglering av styrsystem i stridsflygplan. Det som har tagits fram av kandidatgruppen är en kvadratisk optimeringslösare som även kan köras från MATLAB. Undersökningar har gjorts om det går att implementera optimeringsalgoritmen i programspråket C med projektets tidsbegränsning, om lösaren kan bli lika snabb som den kommersiella produkten Gurobi och om projektet går att utföra utan någon speciell utvecklingsmetodik. I resultat går det att se att det gick att implementera optimeringsalgoritmen, att lösaren inte kunde bli lika snabb som Gurobi och att kandidatgruppen inte använde någon speciell utvecklingsmetodik. Slutsatser kandidatgruppen har dragit ar att valet av optimeringsalgoritm inte var helt genomtänkt, att mer mer tid och resurser hade lösaren kanske kunnat blivit lika snabb som Gurobi och att arbetet fungerade tillfredsställande utan någon speciell utvecklingsmetod.
2

On-line uppdragsplanering baserad på prediktionsreglering / On-line mission planning based on Model Predictive Control

Sjanic, Zoran January 2001 (has links)
Modern air battles are very dynamic and fast, and put extreme pressure on pilots. In some unpredictable situations, like new discovered threats or mission plan deviation because of enemy aircraft, the pilots might need to replan their predefined flight route. This is very difficult, if not impossible, to do since numerous factors affect it. A system that can help the pilots to do such a thing is needed. P revious work in this field has involved methods from artificial intelligence like A*-search. In this master thesis, implementation of a replanning system based on a control theory method, Model Predictive Control (MPC), is examined. Different factors influencing the path, such as terrain and threats, are included in the algorithm. The results presented in this thesis show that MPC solves the problem. As with every method there are some drawbacks and advantages, but as a summary the method is a very promising one and is worth further development. Proposals of future work and different improvements of the algorithms used here are presented in this report as well.
3

On-line uppdragsplanering baserad på prediktionsreglering / On-line mission planning based on Model Predictive Control

Sjanic, Zoran January 2001 (has links)
<p>Modern air battles are very dynamic and fast, and put extreme pressure on pilots. In some unpredictable situations, like new discovered threats or mission plan deviation because of enemy aircraft, the pilots might need to replan their predefined flight route. This is very difficult, if not impossible, to do since numerous factors affect it. A system that can help the pilots to do such a thing is needed. P</p><p>revious work in this field has involved methods from artificial intelligence like A*-search. In this master thesis, implementation of a replanning system based on a control theory method, Model Predictive Control (MPC), is examined. Different factors influencing the path, such as terrain and threats, are included in the algorithm. </p><p>The results presented in this thesis show that MPC solves the problem. As with every method there are some drawbacks and advantages, but as a summary the method is a very promising one and is worth further development. </p><p>Proposals of future work and different improvements of the algorithms used here are presented in this report as well.</p>
4

Reference Governor for Flight Envelope Protection in an Autonomous Helicopter using Model Predictive Control / Referensövervakning för flygenvelopsskydd i en autonom helikopter via modellbaserad prediktionseglering

Carlsson, Victor, Sunesson, Oskar January 2014 (has links)
In this master’s thesis we study how Model Predictive Control (MPC) can be fitted into an existing control system to handle state constraints. We suggest the use of reference governing based on the predictive control methodology. The platform for the survey is Saabs unmanned helicopter Skeldar. We develop and investigate different Reference Governor(RG) formulations that can be used together with the already existing stabilizing control system. These different setups show various features regarding model predictive control. One setup is complemented with a pre-filter to prevent aggressive actuator control in response to set-point changes, while the other is developed to handle this in the MPC framework. We also show that one of these RGs can be extended to guarantee stability and convergence. Implementation and real time requirements are also considered in this thesis. For this two different QP-solvers have been used for online solving of the optimization problem that arises from the MPC formulations. For evaluation and analysis the solutions are implemented in an advanced simulation environment developed at Saab and in a hardware-in-the-loop avionics test rig for the Skeldar system.
5

Modeling and Evaluation of Turret Control Systems for Main Battle Tanks

Lyth, Mikael January 2021 (has links)
The aim of the thesis was to implement and compare control methods in a model of a main battle tank. Three controllers were implemented in a two axis gimbal model and their performances were compared. The comparisons were performed using step changes in the reference signal, frequency analysis of an oscillating reference signal and disturbances, and turret mass uncertainties. The results showed that the sliding mode controller had the best performance for both reference changes and disturbance attenuation. The PID controller had a better performance for the change in reference, compared to the model predictive controller, but a significantly worse disturbance attenuation. Due to model approximations, such as assuming ideal engines and noise reduction, the results likely show a better performance than what can be expected if applied on a real main battle tank. Therefore, the results show an upper limit of the stabilization performance of turret and barrel control and should only be used to compare the controllers. / Målet med uppsatsen var att implementera och jämföra reglermetoder för en teoretisk modell av en modern stridsvagn. Tre metoder implementerades i ett tvåaxligt gimbalsystem och deras prestanda utvärderades. Mer specifikt utvärderades regulatorernas respons för en referensändring, en referensstörning och osäkerheter i tornets massa och massfördelning. Utifrån dessa resultat jämfördes sedan reglermetoderna. Resultaten visade att sliding mode regulatorn hade bäst prestanda för både referensändring och referensstörningen när man tittar på frekvensanalys av mät- och processstörningar. PID-regulatorn hade en bättre prestanda än MPC-regulatorn för en referensändring men en sämre respons för en referensstö-rning. På grund av modellförenklingar som till exempel antaganden om ideala motorer och brusreduktion visar resultaten troligen en något bättre prestanda än vad som kan uppnås på en riktigt stridsvagn. Det medför att resultaten visar en övre gräns för vad styrsystemet för en stridsvagns torn- och eldrörsrotation kan uppnå.

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