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3101 Uppsatser om Control stability - Sida 1 av 207

Utveckling av modellbaserad reglering i kommersiella styrsystem

In industrial control systems PID-control remains the prevalent strategy, also for processes that would benefit from model based control. The purpose of this thesis is to evaluate whether model based control can be readily implemented in an industrial control system. To this end a simulated surge tank with a simulated industrial control system is studied. For evaluation two scenarios with specified objectives are selected.Following a review of LQR and versions of MPC, Predictive Functional Control (PFC) is considered the most suitable for implementation. PFC is a form of MPC developed with industrial applications in mind and therefore has several advantages for implementation in an industrial control system.

Förbättrad förbränningsstabilitet i EBK för turbofläktmotor RM12 genom förändrad motorreglering : Improved afterburner combustion stability for turbofan engine RM12 by modified engine control

The engine of JAS 39 Gripen, RM12, has recently been equipped with a new flameholder and a new engine inlet. This change has caused an increased noise level from the engine when the afterburner is in use. The noise level reaches its peak when the afterburner is partially used. The problem is thought to be unstable combustion in the regions around the flameholder. A solution to the problem has been proposed by Volvo Aero.

Frekvensreglering i det nordiska kraftsystemet

Svenska Kraftnät is (together with the other transmission system operators of the Nordic power system) responsible for keeping balance between the generated and demanded power in the Nordic power system. Spontaneous load variations and system disturbances, however, lead to power imbalance followed by frequency variations. The frequency deviations can be limited to an acceptable level by the spinning reserve, mainly by hydro power control. But there are also other system properties which have a great influence on the frequency and system stability. The frequency and voltage dependence of the loads have a direct influence on the power balance.

MEASUREMENT OF C-REACTIVE PROTEIN IN CANINE SERUM ON KONELABAUTOANALYZER 20

An inflammatory reaction is induced after release of proinflammatory mediators such asinterleukin 1 and 6 and tumour necrosis factor ?. These mediators stimulate the liver tosuppress the syntheses of albumin and endure the syntheses of acute phase protein forinstance C-reactive protein. The aim of this paper was to perform a method validation on animmune turbidimetric assay to quantify C-reactive protein in canine serum at the laboratory atSkara Animals Hospital, Skara, Sweden. The validation involved evaluation of the assaylinearity, precision, stability and recovery.The method was proved to be linear for both TruLab control and Medinor control.

Diagnos av stiktion i reglerventiler för prediktivt underhåll

This master thesis reviews advances in detection and diagnosis of static friction (stiction) in control valves. Control valves suffering from stiction results in oscillating control loops which in turn decreases both the process stability and reliability. Perstorp AB sees a necessity to automatically detect stiction in valves before the effects of the malfunctioning valves have become too severe. This thesis presents an introduction to maintenance, control loops and how stiction in valves can affect performance of control loops.A selection of methods presented in the literature are introduced and examined using normal operating data from the site in Perstorp. Common for all selected methods is their intuitive ideas and that they are based on normal operating data and minimum amount of process knowledge.

Regulatorer med styrsignalsbegränsning

This thesis studies the negative impact that control signal saturation may have on a controlled system. Different methods that are used to compensate for this problem are also studied and evaluated. Both sensitivity to disturbances and the effect the method has on the systems'ability to follow a reference signal will be examined. Stability will be discussed, but no conclusions whether the systems are stabilized or not can be drawn. Control signal saturation will lead to a slower behavior in general.

Dammsäkerhetsanalys via stabilitetsberäkningar för Långströmmens kraftverk : En jämförelse mellan olika dimensioneringsmetoder

A detailed dam safety evaluation (in Sweden called FDU) was performed in 2009 by WSP where stability control was performed for Långströmmen power plant with associated spillways. This evaluation concluded that stability could not be ensured, and risk of sliding occurred. The evaluation is based entirely on the recommendations outlined in RIDAS, the power companies guidelines for dam safety, and it is clear that extensive renovations are necessary to stabilize the dam.In this work, the stability will also be checked with guidance through new proposals on guidelines for concrete dams sliding stability, ELFORSK?s report 08:59. This report considered the guidelines in RIDAS as oversimplified, both from an international perspective, but also with regard to the current state of knowledge regarding dam safety.

Utveckling av reglersystem till quadrokopter

The purpose of this project was to further develop and complete a quadcopter that had been built in an earlier course at KTH, so that it could be used for demonstration and education at the school. The quadcopter was at the beginning of the project completed when it came to hardware, and there was some software functionality implemented but no system for automatic stabilization. The main goal of the project was to implement such a system, and to combine it with the previous functionality to make the quadcopter operable and able to fly. To create a functioning and stable ground multiple basic software features has been implemented, and on top of that additional software to improve the safety, stability and functionality. The most important part is the control system that is responsible for converting sensor and control signals to suitable motor values.

Undersökning av mätsystem och regulatorstrukturer för industriella tillämpningar

This thesis is divided in to two different parts. The first part includes examination of the measurementsystem of an industrial robot using a resolver sensor. The main focus is on methods for suppressing noise in the angularvelocity signal without increasing timedelay. Five different methods are investigated. Three of these are based on oversampling: burstsamplingmethod, meanvaluemethod and correlationmethod.

På uppdrag av Allah - En studie av legitimiteten i den saudiarabiska statsapparaten

Since 2003 Saudi Arabia is under attack from domestic Al Qaida-cells which, by random shootings of westerners and bombings of compounds and official state buildings, is trying to challenge the stability of the royal regime. According to Al Qaida, the Royal family is attacked because of their friendly relations to the US and for not implementing Islam in the Saudi society as profound as they ought to. Political analyst finds it obvious that the Islamic Al Qaida-cells by terrorism is trying to erode the stability in the kingdom.An important foundation for stability for any government is legitimacy. The aim of this thesis is to examine the royal legitimacy strategy in the state bureaucracy of Saudi Arabia. The question at issue is: how has the royal family constructed the civil, military and religious bureaucracies to maintain and promote stability and legitimacy?The thesis focuses on the on three different units within these three bureaucracies and it surveys the way they are staffed and organized to strengthen and maintain legitimacy for the royal family.

Stabilitetsberäkningar och åtgärdsförslag vid islast på Skålandammen

Hydropower is an important source of energy in Sweden and accounts for about 46 % of the total energy production. Sweden has about 1 200 hydropower plants and with the intention of raising the pressure head of the water and to store water, dams are built by the power plants. The storage reservoirs make it possible to adjust the energy production by demand and season. Dams in connection to the reservoirs are subjected to additional loading during periods of high floods or when an icecap in the winter is formed on the reservoirs. In order to maintain the dam safety, the power companies in Sweden are working with guidelines for dam safety from RIDAS.

Risker i flera dimensioner : Om kopplingen mellan designmönstret MVC och projektrisker

The purpose of this project was to further develop and complete a quadcopter that had been built in an earlier course at KTH, so that it could be used for demonstration and education at the school. The quadcopter was at the beginning of the project completed when it came to hardware, and there was some software functionality implemented but no system for automatic stabilization. The main goal of the project was to implement such a system, and to combine it with the previous functionality to make the quadcopter operable and able to fly. To create a functioning and stable ground multiple basic software features has been implemented, and on top of that additional software to improve the safety, stability and functionality. The most important part is the control system that is responsible for converting sensor and control signals to suitable motor values.

Kommersiella Fastighetshyror och Finansiell Stabilitet

In recent years, global organizations safeguarding financial stability has started to track commercial property markets. One of the reasons for this refers to the fact that commercial property constitutes a large share of bank lending. Simultaneously, bank exposures to commercial property are extensive and risky since collateral values are strongly correlated to borrowers cash flows. Since banks are viewed to play a key role for financial stability, studying the relationship is well motivated. To better understand how commercial property markets interact with financial stability, this paper develops an econometric model for studying the commercial rental market.

Effekten av sex veckors coreträning enligt det förkoreograferade programmet Fokus

Core strength is important in order to be able to do all types of daily activities. One way to exercise ones core muscles is according to the pre- choreographed program Fokus. Previous studies have shown that core training gives better balance and stability in the core and also improved techniques, body awareness and control. Aim: To evaluate the core endurance strength, the balance and the studied individuals self estimated body awareness and control after six weeks of training according the pre- choreographed program Fokus. Methods: A total of 14 people volunteered to participate in the study, six of which completed the study.

Effekten av sex veckors coreträning enligt det förkoreograferade programmet Fokus

Core strength is important in order to be able to do all types of daily activities. One way to exercise ones core muscles is according to the pre- choreographed program Fokus. Previous studies have shown that core training gives better balance and stability in the core and also improved techniques, body awareness and control. Aim: To evaluate the core endurance strength, the balance and the studied individuals self estimated body awareness and control after six weeks of training according the pre- choreographed program Fokus. Methods: A total of 14 people volunteered to participate in the study, six of which completed the study.

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