Dissertationen: „Electrical control“

1

Huang, Hong. „Electrical two speed transmission and advanced control of electric vehicles“. Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0002/NQ38349.pdf.

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2

SERPI, ALESSANDRO. „Predictive control of electrical drives“. Doctoral thesis, Università degli Studi di Cagliari, 2009. http://hdl.handle.net/11584/266015.

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In this work, the application of the Predictive Control Technique to the electrical drives has been considered and discussed, especially in comparison with the employment of the traditional control techniques. First of all, a predictive control algorithm for the Brushless DC drive is developed with the aim of improving the traditional current commutation as best as possible. Then, a novel predictive control algorithm is proposed by imposing both the reference torque value and the minimum Joule losses condition. Then, several predictive control algorithms are proposed for the Synchronous Reluctance Machine, taking into account the magnetic saturation effects too. They are based either on the traditional control strategy or on optimization criteria, such as the minimum steady state Joule losses condition and the fastest achievement of the reference torque value. Finally, a novel predictive Direct Torque Control algorithm is synthesized for the Asynchronous Machine, by taking into account both voltage saturation and current limitation constraints. The synthesizing procedure adopted is also shown by an interesting graphical representation. The effectiveness of all the proposed algorithms has been properly tested by appropriate simulation studies, performed in the Matlab Simulink environment. The corresponding results have highlighted how the employment of the Predictive Control Technique allows better performances compared to those achievable by the traditional control ones.
In this work, the application of the Predictive Control Technique to the electrical drives has been considered and discussed, especially in comparison with the employment of the traditional control techniques. First of all, a predictive control algorithm for the Brushless DC drive is developed with the aim of improving the traditional current commutation as best as possible. Then, a novel predictive control algorithm is proposed by imposing both the reference torque value and the minimum Joule losses condition. Then, several predictive control algorithms are proposed for the Synchronous Reluctance Machine, taking into account the magnetic saturation effects too. They are based either on the traditional control strategy or on optimization criteria, such as the minimum steady state Joule losses condition and the fastest achievement of the reference torque value. Finally, a novel predictive Direct Torque Control algorithm is synthesized for the Asynchronous Machine, by taking into account both voltage saturation and current limitation constraints. The synthesizing procedure adopted is also shown by an interesting graphical representation. The effectiveness of all the proposed algorithms has been properly tested by appropriate simulation studies, performed in the Matlab Simulink environment. The corresponding results have highlighted how the employment of the Predictive Control Technique allows better performances compared to those achievable by the traditional control ones.

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3

Bourilkov, Jordan Todorov. „Electrical pH control in aqueous solutions“. Thesis, City University London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418981.

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4

Yeoh, Seang Shen. „Control strategies for the More Electric Aircraft starter-generator electrical power system“. Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/34098/.

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The trend towards development of More Electric Aircraft (MEA) has been driven by increased fuel fossil prices and stricter environmental policies. This is supported by breakthroughs in power electronic systems and electrical machines. The application of MEA is expected to reduce the aircraft mass and drag, thereby increasing fuel efficiency and reduced environmental impact. The starter-generator (S/G) scheme is one of the solutions from the MEA concept that brings the most significant improvement to the electrical power generation system. A S/G system is proposed from the possible solutions brought by the MEA concept in the area of electrical power generation and distribution. Due to the wide operating speed range, limited controller stability may be present. This thesis contributes to the control plant analysis and controller design of this MEA S/G system. The general control requirements are outlined based on the S/G system operation and the control structure is presented. The control plants are derived specifically to design the controllers for the S/G control scheme. Detailed small signal analysis is performed on the derived plant while taking into consideration the aircraft operating speed and load range. A safe range for the controller gains can then be determined to ensure stable operation throughout the S/G operation. Adaptive gain and a novel current limit modifier are proposed which improves the controller stability during S/G operation. Model predictive control is considered as an alternative control strategy for potential control performance improvements with the S/G system. The technical results and simulations are supported by Matlab®/Simulink® based models and validated by experimental work on a small scaled drive system.

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5

Alahakoon, Sanath. „Digital motion control techniques for electrical drives“. Doctoral thesis, KTH, Electric Power Systems, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-2954.

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Digital motion control area toady is a well-established one,which is believed to be first initiated by power electronicengineers in the early seventies. Modern digital controltheory, advances in digital signal processor andmicrocontroller technology and recent developments in powerelectronic devices have made this field a very competitive one.The objective of this thesis is to present some digital motioncontrol techniques that can be applied for electrical drives.This is done by investigating two motion control problemsassociated with electrical drives; namely, precision motioncontrol and sensorless motion control.

Application of digital motion control techniques for preciseeccentric rotor positioning of an induction machine with ActiveMagnetic Bearings (AMB) is the first application problemaddressed in the thesis. The final goal is to prepare aflexible test rig for the study of acoustic noise in standardinduction machines with rotor eccentricity. AMB control hasbeen a challenging task for the control engineers since itsinvention. Various types of control techniques - both analogand digital - have been attempted with a lot of success overthe past years. In the application area of rotating machines,the whole concept of AMB control means stabilizing the rotor ofthe machine in the exact center of the radial AMBs andmaintaining that position under magnetic disturbance forcesexerted on it by the stator under running condition. The aim ofthe first part of the thesis is to present several digitalmotion control techniques that would give the user theflexibility of moving the rotor to any arbitrary position inthe air gap and maintaining that eccentric position.

The second part of the thesis dealt with sensorless controlof Permanent Magnet Synchronous Motors (PMSM) for high-speedapplications. Conventional PMSM drives employ a shaft-mountedencoder or a resolver to identify the rotor flux position. Itis advantageous to eliminate the shaft-mounted sensor byincorporating sensorless control schemes for PMSM drive systemsdue to many reasons. A sensorless control scheme must besufficiently robust and less computationally heavy for it to besuccessful. However, reliable performance of a sensorlesscontrol drive strategy is always an integration of many digitalmotion control techniques. Implementation of fast currentcontrol by overcoming sampling delay in the discrete system isa key issue in this respect. Suitable speed control with areliable controller anti-windup mechanism is also essential.Compensation techniques for the inverter non-idealities mustalso be incorporated to achieve better performance. In thispart of the thesis, all these aspects of a well performingsensorless control strategy for a PMSM are investigated.Frequency dependent machine parameter variation, which is asignificant practical problem against achieving the expectedperformance of these control strategies, is also addressed.

Most of the problems addressed in the thesis are related toimplementation issues of a successful control method. Theapproach in this work is to find solutions to those applicationissues from the automatic control theory.

Keywords:Eccentric rotor positioning, modeling,integrator anti-windup, bumpless transfer, identification,periodic disturbance cancellation, sampling delay compensation,cascaded control, speed and position estimation, compensationsfor non-idealities, parameter estimation, start-uptechnique

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6

Radan, Damir. „Integrated Control of Marine Electrical Power Systems“. Doctoral thesis, Norwegian University of Science and Technology, Faculty of Engineering Science and Technology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1984.

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This doctoral thesis presents new ideas and research results on control of marine electric power system.

The main motivation for this work is the development of a control system, power management system (PMS) capable to improve the system robustness to blackout, handle major power system faults, minimize the operational cost and keep the power system machinery components under minimal stress in all operational conditions.

Today, the electric marine power system tends to have more system functionality implemented in integrated automation systems. The present state of the art type of tools and methods for analyzing marine power systems do only to a limited extent utilize the increased knowledge available within each of the mechanical and electrical engineering disciplines.

As the propulsion system is typically consisted of the largest consumers on the vessel, important interactions exists between the PMS and vessel propulsion system. These are interacted through the dynamic positioning (DP) controller, thrust allocation algorithm, local thruster controllers, generators' local frequency and voltage controllers. The PMS interacts with the propulsion system through the following main functions: available power static load control, load rate limiting control and blackout prevention control (i.e. fast load reduction). These functions serve to prevent the blackout and to ensure that the vessel will always have enough power.

The PMS interacts with other control systems in order to prevent a blackout and to minimize operational costs. The possibilities to maximize the performance of the vessel, increase the robustness to faults and decrease a component wear-out rate are mainly addressed locally for the individual control systems. The solutions are mainly implicative (for e.g. local thruster control, or DP thrust allocation), and attention has not been given on the interaction between these systems, the power system and PMS. Some of the questions that may arise regarding the system interactions, are as follows: how the PMS functionality may affect a local thruster control, how the local thruster control may affect the power system performance, how some consumers may affect the power system performance in normal operations and thus affect other consumers, how the power system operation may affect the susceptibility to faults and blackout, how various operating and weather conditions may affect the power system performance and thus propulsion performance though the PMS power limiting control, how propulsion performance may affect the overall vessel performance, which kind of faults can be avoided if the control system is re-structured, how to minimize the operational costs and to deal with the conflicting goals. This PhD thesis aims to provide answers to such questions.

The main contributions of this PhD thesis are:

− A new observer-based fast load reduction system for the blackout prevention control has been proposed. When compared to the existing fast load reduction systems, the proposed controller gives much faster blackout detection rate, high reliability in the detection and faster and more precise load reduction (within 150 miliseconds).

− New advanced energy management control strategies for reductions in the operational costs and improved fuel economy of the vessel.

− Load limiting controllers for the reduction of thruster wear-out rate. These controllers are based on the probability of torque loss, real-time torque loss and the thruster shaft

accelerations. The controllers provide means of redistributing thrust from load fluctuating thrusters to less load fluctuating ones, and may operate independently of the thrust allocation system. Another solution is also proposed where the load limiting controller based on thrust losses is an integrated part of DP thrust allocation algorithm.

− A new concept of totally integrated thrust allocation system, local thruster control and power system. These systems are integrated through PMS functionality which is contained within each thruster PLC, thereby distributed among individual controllers, and independent of the communications and dedicated controllers.

− Observer-based inertial controller and direct torque-loss controller (soft anti-spin controller) with particular attention to the control of machine wear-out rate. These controller contribute to general shaft speed control of electrical thrusters, generators and main propulsion prime movers.

The proposed controllers, estimators and concepts are demonstrated through time-domain simulations performed in MATLAB/SIMULINK. The selected data are typical for the required applications and may differ slightly for the presented cases.

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7

Fan, Minlin. „A subsea electrical actuator and control system“. Thesis, University of Liverpool, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398584.

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8

Laird, E. A. „Electrical control of quantum dot spin qubits“. Thesis, Lancaster University, 2009. http://eprints.lancs.ac.uk/124373/.

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9

Wenzel, Brian Jeffrey. „CLOSED-LOOP ELECTRICAL CONTROL OF URINARY CONTINENCE“. Case Western Reserve University School of Graduate Studies / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=case1120932206.

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10

Birch, Alan Philip. „Adaptive load frequency control of electrical power systems“. Thesis, Durham University, 1988. http://etheses.dur.ac.uk/6448/.

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The thesis describes Load Frequency Control techniques which may be used for real-time on-line control of large electrical power systems. Traditionally the frequency control of power systems has been carried out using standard fixed parameter control schemes, which give control over the immediate steady- state error and the long term accumulated frequency error, but do not account for the fact that system conditions can alter due to the change in consumer load and generating patterns. The thesis presents a method of controlling the system frequency using adaptive control techniques, which ensure that optimal control action is calculated based on the present system conditions. It enables the system operating point to be monitored so that optimal control may continue to be calculated as the system operating point alters. The proposed method of frequency control can be extended to meet the problems of system interconnection and the control of inter-area power flows. The thesis describes the work carried out at Durham on a fixed parameter control scheme which led to the development of an adaptive control scheme. The controller was validated against a real-time power system simulator with full Energy Management software. Results are also presented from work carried out at the Central Electricity Research Laboratories under the C.A.S.E award scheme. This led to the development of a power system simulator, which along with the controller was validated on-line with the Dispatch Project used by the Central Electricity Generating Board.

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11

CAVANINI, Luca. „Model Predictive Control for Electrical and Mechatronic Systems“. Doctoral thesis, Università Politecnica delle Marche, 2018. http://hdl.handle.net/11566/253007.

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L'attività di ricerca presentata in questa tesi riguarda il progetto e lo sviluppo di sistemi di controllo basati sulla predizione del comportamento del processo da controllare, in modo da ottenere prestazioni di controllo ottimizzate. I processi presi in considerazione sono convertitori elettrici di potenza e sistemi meccatronici. L'uso di algoritmi di controllo basati sul modello per predire l'evoluzione del processo è stata limitato a lungo a sistemi caratterizzati da dinamiche lente. Ciò è dovuto al tempo necessario a calcolare la legge di controllo, che prevede la risoluzione di un problema di minimizzazione vincolata da efettuarsi nell'intervallo di campionamento indicato nelle specifiche di progetto (in tempi minori in caso di unità di controllo che gestiscono più processi). Negli ultimi anni, la potenza di calcolo delle schede di controllo embedded è significativamente aumentata, permettendo di applicare le tecniche di controllo predittivo a sistemi caratterizzati da dinamiche veloci. Considerando le potenzialità del controllo predittivo, in questa tesi differenti leggi di controllo sono state sviluppate per far fronte a problematiche di controllo relative a diferenti casi di studio. Approcci MPC basati su modelli lineari tempo invariati (LTI) sono state considerati per il controllo di sistemi di micro-posizionamento piezoelettrici e di convertitori di potenza. In questo ambito sono state presentate le basi teoriche che permettono di applicare con successo tali tecniche su schede di controllo caratterizzate da ridotta potenza computazionale. Controllori per sistemi avionici e marini sono stati inoltre considerati. In questo ambito, sono stati sviluppati modelli lineari a parametri tempo varianti (LPV) rispetto ai quali sono stati sviluppati i sistemi di controllo. In questo ambito è stata sviluppata inoltre un'innovativa tecnica che permette di ridurre il carico computazionale richiesto dagli algoritmi MPC basati su modelli LPV, di modo da permetterne l'implementazione su schede embedded. Tutti i sistemi di controllo sviluppati sono stati testati su processi reali laddove possibile, ed in alternativa su simulatori altamente realistici.
The research activity presented in this thesis concerns the design and the development of control systems based on the prediction of the behavior of the process to be controlled, in order to obtain optimized control performance. The processes taken into account are electrical power converters and mechatronic systems. The use of model-based algorithms to predict the process evolution has been limited for a long time to systems featured by slow dynamics. This issue is related to the time needed to compute the control law, which requires the real time resolution of a constrained optimization problem, that must be always solved in a prescribed amount of time, usually corresponding to the sampling period or even shorter in multi-purpose control units. In recent years the computational the increasing power of control units has allowed the application of predictive control algorithms to complex and faster dynamic processes. Considering the potential of the predictive control to solve multivariable control problems, thanks to the optimized performance and the efective handling of systems constraints, in this thesis diferent control algorithms have been developed to solve problems linked to several case studies. Linear Time Invariant (LTI) model-based MPC approaches have been considered for micro-positioning piezoelectric systems and power converters. In this context theoretical conditions to efectively apply MPC for pre-compensed systems on low computational hardware have been given. Control approaches for avionic and marine systems have been also considered. In this context Linear Parameter Varying (LPV) models have been developed and an innovative solution has been studied to reduce the computational efort of LPV-based MPC on em- bedded control platform. All the above controllers have been tested on real processes, wherever possible, and through highly realistic simulators.

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12

Boodhoo, Lana Elizabeth. „Electrical therapies for rhythm control of atrial fibrillation“. Thesis, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511894.

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13

Stone, Barry A. „Control strategies for functional electrical stimulation induced cycling“. Thesis, University of Glasgow, 2005. http://theses.gla.ac.uk/1533/.

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Functional Electrical Stimulation cycling ergometers and mobile cycling systems have been developed over a number of years to allow Spinal Cord Injured persons to exercise. Standard able bodied exercise tests are adapted and applied to paraplegic cyclists. A modified recumbent tricycle is instrumentated with an electric motor and sensors to measure cadence and the power produced by the cyclist at the crank. They are then integrated to a stimulator and a laptop computer. The tricycle is mounted on an indoor cycling trainer to provide a novel test bed for the implementation of exercise testing. Controllers are desired to control cadence and power during cycling. Identification of input-output data for the cadence-motor loop and the power-stimulation loop is undertaken. Three muscle groups are stimulated on a paraplegic subject to produce power. Models are identified of the power and cadence systems. Thereafter controllers are designed, via polynomial methods. The results show that the controllers are robust during cadence tracking, power tracking and for disturbance rejection. The controllers can be accurately applied to exercise testing protocols. The concept of VO2 control is induced. VO2 is the rate of oxygen uptake during exercise. VO2-power dynamics are identified and as before a model is fitted to the measured data. Controllers are designed and further modified, as the understanding of the VO2 dynamics is developed. This is through a series of tests to improve the accuracy of the control. The results illustrate that VO2 control is a novel and practical application. These findings develop the field of functional Electrical Stimulation Induced Cycling within the laboratory. However further work is required to develop this application outside laboratory conditions.

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14

Singh, B. „Microprocessor control and instrumentation of electrical power systems“. Thesis, University of Bradford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379865.

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15

Lane, Rodney. „Control of upper-limb functional neuromuscular electrical stimulation“. Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/419062/.

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Functional electrical stimulation (FES) is the name given for the use of neuromuscular electrical stimulation to achieve patterns of induced movement which are of functional benefit to the user. System are available that use FES to aid persons who have suffered an insult to the motor control region of the brain and been left with movement impairment. The aim of this research was to investigate methods of providing an FES system that could have a beneficial effect in restoring arm function. The techniques for applying upper-limb stimulation are well established, however the methods of controlling it to provide functional use remain lacking. This is because upper-limb movement can be difficult to measure and quantify as the starting point for any movement may not be well defined. Moreover the movements needed to complete a useful function such as reaching and grasping requires the coordinated control of a number of muscle groups, and that relies on being able to track the position of the limb. Effective control of FES for the arm requires reliable feedback about the position and state of the limb. Electromyograms (EMG) are a measure of the very small electrical signals that are emitted whenever a muscle is ‘fired’ to move. EMG can be used to detect muscle activity and so can be a useful feedback control input. It does however have a number of drawbacks that this research sought to address by combining the method with external motion sensors. The intension had been to use the motion sensors to track the position of the limb and then use the EMG measurements to detect the wearer’s movements. FES could then be used to assist the wearer in making a desired movement. Initial studies were done to separately investigate the motion sensing and the EMG measurement components of the system. However before these could be combined a more interesting observation was made relating to bioimpedance. A study of bioimpedance measurements found a relationship between tissue impedance changes and muscle activity. Different methods for measuring bioimpedance where investigated and the results compared, before a practical technique for capturing measurements was developed and demonstrated. A new set of test equipment was made using these finding. Subsequent results using this equipment were able to demonstrate that bioimpedance measurement could be taken from a limb while FES was being used, and that these measurement could be used as a feedback signal to control the FES to maintain a target limb position. This work forms the basis of a novel approach to the control of FES that uses feedback from the user’s limb to determine the position of the limb in free space without need for additional sensors.

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16

Grimshaw, Paul Edward. „Electrical control of solute transport across polyelectrolyte membranes“. Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14425.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1989.
Includes bibliographical references.
Supported in part by NSF ERC. CDR-8500003 Supported in part by NSF. CBT-8512814
by Paul E. Grimshaw.
Ph.D.

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17

Freebairn, David Alexander. „Electrical control of bacterial adherence to conducting polymers“. Thesis, Queen's University Belfast, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.680117.

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In this thesis, low direct currents (DC) have been shown to successfully reduce bacterial adherence to conducting polymers in unique electrically modified flow devices without the aid of an antimicrobial agent. However, alternating currents (AC) and radio-frequency currents (RF) were not found to be effective. The design and manufacture of these new DC and RF flow devices has been comprehensively documented within, accompanied by relevant standard operating procedures and experimental designs. Additionally, the thesis includes a review of seminal bioelectric literature and discusses the potential for exciting future developments in this multidisciplinary field of research. These findings are ultimately intended to facilitate the design of new indwelling medical devices (IMDs) as well as electrically sterilized polymer surfaces for a wide range of far-reaching applications in industries where bacterial biofilms proliferate

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18

Miao, Xia Ph D. Massachusetts Institute of Technology. „Toward distributed control for autonomous electrical energy systems“. Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/128321.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2020
Cataloged from PDF of thesis.
Includes bibliographical references (pages 136-144).
In this thesis we study the problem of enabling autonomous electrical energy systems (AEESs) by means of distributed control. We first propose a modular modeling approach that represents a general electrical energy system (EES) as a negative feedback configuration comprising a planar electrical network subsystem and a subsystem of single-port components. The input-output specifications of all components are in terms of power and voltage. This mathematical modeling supports the basic physical functionality of balancing power supply and demand at the acceptable Quality of Service (QoS). These input-output specifications are met by the controllable components equipped with the newly proposed distributed control. We show that these controllers enable stable and feasible system-level closed-loop dynamics. Moreover, an interactive algorithm for autonomous adjustments of their controller set points based on the information exchange with neighboring components is introduced. This serves as a proof-of-concept illustration of how components adjust their power and voltage toward a system-level equilibrium. Such process is the basis for autonomous reconfigurable operation of small microgrids. As the first step toward scaling up the proposed concepts, we consider the problem of enhanced automatic generation control (E-AGC) for systems with highly dynamic load variations, including effects of intermittent renewable generation. Further work is needed to fully generalize this approach for control design of large-scale EES. In addition to theoretical results, we also report the results of several numerical and hardware tests. These show the effectiveness of the proposed approach in fairly complex scenarios, including unplanned large faults and hard-to-predict fast-varying power disturbances.
by Xia Miao.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science

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19

Ramsey, Laurence. „Control of molecular motor motility in electrical devices“. Thesis, University of Liverpool, 2014. http://livrepository.liverpool.ac.uk/18913/.

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In the last decade there has been increased interest in the study of molecular motors. Motor proteins in particular have gained a large following due to their high efficiency of force generation and the ability to incorporate the motors into linear device designs. Much of the recent research centres on using these protein systems to transport cargo around the surface of a device. The studies carried out in this thesis aim to investigate the use of molecular motors in lab-on-a-chip devices. Two distinct motor protein systems are used to show the viability of utilising these nanoscale machines as a highly specific and controllable method of transporting molecules around the surface of a lab-on-a-chip device. Improved reaction kinetics and increased detection sensitivity are just two advantages that could be achieved if a motor protein system could be incorporated and appropriately controlled within a device such as an immunoassay or microarray technologies. The first study focuses on the motor protein system Kinesin. This highly processive motor is able to propel microtubules across a surface and has shown promise as an in vitro nanoscale transport system. A novel device design is presented where the motility of microtubules is controlled using the combination of a structured surface and a thermoresponsive polymer. Both topographic confinement of the motility and the creation of localised ‘gates’ are used to show a method for the control and guidance of microtubules. Two further studies use the actin myosin motor protein system. Both concentrate on the manipulation of actin filaments, gliding on immobilised myosin, by DC electrical fields. Motor protein is adsorbed onto several surface chemistries with varying protein adsorption properties. A range of electrical fields are applied to the motility assay and the performance is analysed in terms of the directionality and any changes in the average velocity of filaments on each surface. This enables us to attribute surface properties to particular motility characteristics and hypothesise as to the nature of protein adsorption. The same electrical motility device is used with an alternative method to allow a more detailed study of the effect of surface chemistry on the motility function and the response of the motility after exposure to an electrical field. The movement of actin filaments on myosin motors is accelerated by a DC electrical field. Upon termination of the field the motility is allowed to return to pre-field function and this section of the procedure is analysed together with the data from the previous study to draw conclusions on the protein adsorption properties of each surface. Both chapters are used to draw conclusions on the response of the motor protein system when it is adsorbed on different surface chemistries. The investigations carried out in this thesis are used to show both novel ways of controlling motor protein motility and also to highlight aspects of design that need to be taken into consideration when incorporating motor proteins into lab-on-a-chip devices. The electrical motility device in particular has proved to be a dynamic and inexpensive tool in investigating motor protein motility.

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20

Loukarakis, Emmanouil. „Decentralised optimisation and control in electrical power systems“. Thesis, Durham University, 2016. http://etheses.dur.ac.uk/11601/.

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Emerging smart-grid-enabling technologies will allow an unprecedented degree of observability and control at all levels in a power system. Combined with flexible demand devices (e.g. electric vehicles or various household appliances), increased distributed generation, and the potential development of small scale distributed storage, they could allow procuring energy at minimum cost and environmental impact. That however presupposes real-time coordination of demand of individual households and industries down at the distribution level, with generation and renewables at the transmission level. In turn this implies the need to solve energy management problems of a much larger scale compared to the one we currently solve today. This of course raises significant computational and communications challenges. The need for an answer to these problems is reflected in today’s power systems literature where a significant number of papers cover subjects such as generation and/or demand management at both transmission and/or distribution, electric vehicle charging, voltage control devices setting, etc. The methods used are centralized or decentralized, handling continuous and/or discrete controls, approximate or exact, and incorporate a wide range of problem formulations. All these papers tackle aspects of the same problem, i.e. the close to real-time determination of operating set-points for all controllable devices available in a power system. Yet, a consensus regarding the associated formulation and time-scale of application has not been reached. Of course, given the large scale of the problem, decentralization is unavoidably part of the solution. In this work we explore the existing and developing trends in energy management and place them into perspective through a complete framework that allows optimizing energy usage at all levels in a power system.

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21

Björklund, Marcus, und Eric Fjärstedt. „Active Stabilizer : Independent Project in Electrical Engineering“. Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-324765.

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22

PRUSAKIEWICZ, LUKAS, und FREDRIK LINDSTROM. „Electrical skateboard with cruise control : Comparing energy consumption with and without cruise control“. Thesis, KTH, Maskinkonstruktion (Inst.), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-226664.

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The use of electric skateboards as small transport vehicleshas gained in popularity during the latest years, and thereare numerous manufacturers on the market.This report will go through the building of an electricskateboard and implementation of a cruise control. Thiswill be done using an Arduino UNO board and a rotaryencoder to read the speed of the skateboard. The speed ofthe skateboard can also be manually controlled by the riderusing a hand held controller.The thesis of the report is to compare the energy consumptionwith and without the use of cruise control. Thisis done by building two sensors measuring voltage and currentover the motor, to later calculate the energy consumedwhen the skateboard is driven. A number of tests wereconducted and the results show that use of cruise controlconsumes more energy in most cases.
Användning av elektriska skateboards som kompakta transportmedelhar växt i popularitet under de senaste åren, ochdet finns flera tillverkare på marknaden.Denna rapport går igenom tillverkandet av en elektriskskateboard med implementering av en farthållare. Dettagörs med ett Arduino UNO kort och en pulsgivare för attmäta skateboardens hastighet. Hastigheten kan även manuelltbestämmas av användaren med en handkontroll.I avhandlingen jämförs energiförbrukningen med ochutan användning av farthållaren. För att jämföra dettabyggs två sensorer som mäter spänning och ström över motorn.Detta för att sedan beräkna energin som förbrukasnär skateboarden körs. Ett flertal tester utfördes och resultatetvisar att användningen av farthållaren i de flestafallen förbrukar mer energi.

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Berry, Randall A. (Randall Alexander). „A linear control approach to ATM congestion control“. Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40234.

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Okafor, Nelson. „Analysis and control of nonlinear phenomena in electrical drives“. Thesis, University of Newcastle Upon Tyne, 2013. http://hdl.handle.net/10443/1839.

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Electrical motors are key to the growth of any modern society. In order to ensure optimal utilisation of the motors, the shaft speed and armature current must be controlled. Currently, the most efficient way of achieving both speed and current control in electrical motors is through power electronic switching, thus making the system both nonlinear and time varying. The combination of electric motors and control electronics is referred to as electric drives. Due to the inherent nonlinear nature of electrical drives, the system is prone to complex dynamical phenomena including bifurcations, chaos, co-existing attractors and fractal basin boundaries. The types of nonlinear phenomena that occur in some of the more common electrical drive systems, namely permanent magnet dc (PMDC) drives, series connected dc (SCDC) drives and switched reluctance motor (SRM) drives, are considered for analysis in this project. The nominal steady state behaviour of these drives is a periodic orbit with a mean value close to the reference value. But as some system parameters are being varied, the nominal orbit of the system referred to as the period-1 orbit, may lose its stability leading to the birth of new attracting orbit that is periodic, quasi-periodic or chaotic in nature. The most common technique for performing stability analysis of a periodic orbit is the Poincaré map approach, which has been successfully applied in DC-DC converters. This method involves reducing the continuous time dynamical system into a discrete time nonlinear iterative map and the periodic orbit into a fixed point. The stability of the periodic orbit then depends on the eigenvalue of the Jacobian matrix of the map evaluated at the fixed point. However, for some power electronic based system the nonlinear map cannot be derived in closed form due to the transcendental nature of the equation involved. In this project, the recently introduced Monodromy matrix approach is employed for the stability analysis of the periodic orbit in electrical drives. This method is based on Filippov’s method of differential inclusion and has been successfully applied in the stability analysis of periodic orbits in both low order and higher order DC-DC converters. This represents the first application of the technique in electrical drives. The Monodromy matrix approach involves computing the State Transition Matrix (STM) of the system around the nominal orbit including the STM at the switching manifold (sometimes referred to as the Saltation matrix). Also, by manipulating some of the parameters in the Saltation matrix, it is possible to control the instabilities and thus extend the system parameter range for nominal period-1 operation. The experimental validation of the nonlinear phenomena in a proportional integral (PI) controlled PMDC drive, which is absent in literature, is presented in this thesis. The system was implemented using dsPIC30F3010 which is a low cost and high performance digital signal controller.

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Sparks, Rachel Elizabeth. „Mechanical and electrical control of transport through single molecules“. Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.656861.

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The field of molecular electronics is continuously striving towards ever smaller electronic devices. To achieve this an intricate understanding of the electrical properties of molecules connected to metallic leads is vital. This thesis derives a general analytical formula, that describes the transmission through a single molecule, with the advantage that it can be evaluated on a pocket calculator. The tight binding model is applied to a multi-branch structure to derive the probability of transmission through the system, the results of which are tested against ab-initio simulations, which utilise a combination of Density Functional Theory (DFT) and the Green's function formalism to compute the transmission coefficient. The results highlight a range of interference effects in single and multi-branched structures and show a close agreement to tight binding formula. Further to this a study of the effects of an external electric field applied to a molecular junction is presented, where the aim is to construct a molecular switch based upon 7f-7f and van der Waals (vdW) interactions. Polycyclic Aromatic Hydrocarbons (PAH) are found to adsorb to each other, whereby the barriers to rotation of the adsorbed molecule relative to the base molecule can be influenced by an external electric field, leading to stable states that can be identified from the energy minimum of the system. A study of P AH systems is presented leading to a proposed molecular switch based upon applying an electric field to control the energy minimum.

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Kirtley, C. „Control of functional electrical stimulation with extended physiological proprioception“. Thesis, University of Strathclyde, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292029.

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Kershaw, Robert Andrew. „Retrieved voluntary electromyogram signals for functional electrical stimulation control“. Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295098.

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Agreda, Adrian. „Electrical control of the nonlinear properties of plasmonic nanostructures“. Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCK010.

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Ce travail rassemble les technologies de nanoélectronique et de nano-photonique pour créer un dispositif électro-plasmonique dont les propriétés optiques linéaires et non linéaires sont contrôlées électriquement. Ici, nous présentons la première démonstration de la modulation de photoluminescence non linéaire par des moyens électriques dans un cas d'étude simple. A cette fin, les nanoantennes plasmoniques sont interfacées avec des connexions électriques induisant des régions localisées d’accumulation et de déplétion d'électrons et affectant ainsi la réponse optique. De plus, une analyse complète de la photoluminescence non linéaire dans les nanofils plasmoniques est réealisée. La délocalisation et le transport des non-linéarités apportées par de telles structures permettent l’activation à distance des signaux. Différents aspects, dont les mécanismes sous-jacents à la modulation électrique et les processus dictant la généeration de photoluminescence non linéaire, sont systématiquement explorés
This work brings nano-electronics and nano-photonics technologies together to create an electron- plasmon device whose linear and nonlinear optical properties are electrically controlled. Here, we present the first demonstration of nonlinear photoluminescence modulation by electrical means in an uncluttered configuration. To this purpose, plasmonic nanoantennas are interfaced with elec- trical connections inducing localized regions of electron accumulation and depletion and therefore affecting the optical response. Additionally, a complete analysis of the nonlinear photoluminescence in plasmonic nanowires is carried out. The delocalization and transport of nonlinearities provided by such structures allow the remote activation of the signals. Different aspects including the un- derlying mechanisms behind the electrical modulation and the processes dictating the nonlinear photoluminescence generation are systematically explored

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Hambrick, Joshua Clayton. „Configurable, Coordinated, Model-based Control in Electrical Distribution Systems“. Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/37792.

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Utilities have been planning, building, and operating electrical distribution systems in much the same way for decades with great success. The electrical distribution system in the United States has been consistently reliable; an impressive feat considering its amazing complexity. However, in recent years, the electrical distribution system landscape has started to undergo drastic changes. Emerging applications of technologies such as distributed generation, communications, and power electronics offer both opportunities and challenges to power system operators as well as customers and developers. In this work, Graph Trace Analysis along with an integrated system model are used to develop algorithms and analysis methods necessary to facilitate the implementation of these new technologies on the electrical distribution system. A penetration limit analysis is developed to analyze the impact of distributed generation on radial distribution feeders. The analysis considers generation location, equipment rating, voltage violations, and flicker to determine the amount of generation that can be safely attached to a circuit. A real-time, hierarchical, model-based control method is developed that coordinates the operation of all control devices on electrical distribution circuits. The controller automatically compensates for changes in circuit topology as well as the addition or removal of control devices from the active circuit. Additionally, the controller allows the integration of modern, "smart" equipment with legacy control devices to facilitate incremental modernization strategies. Finally, a framework is developed to allow the testing of new analysis and control methodologies for electrical distribution systems. The framework can be used to test scenarios over multiple consecutive hourly or sub-hourly time points. The framework is used to demonstrate the effectiveness of the model-based controller versus existing operating methods for a distribution circuit test case.
Ph. D.

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Zhao, Dong. „Exploring Construction Safety and Control Measures through Electrical Fatalities“. Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/71712.

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Globally, construction is considered a hazardous industry with a disproportionate amount of fatal and non-fatal injuries as compared to other industries. Electrocution is named as one of the "fatal four" causes for construction injuries by the Occupational Safety and Health Administration (OSHA). In the United States, an average of 47.9% electrical fatalities occurred in the construction industry from 2003 to 2012, according to the U.S. Department of Labor. These fatalities include both electrical workers and non-electrical workers. Such a disproportionate rate suggests a need of research to improve construction safety and reduce injuries due to electrocution. However, there is a lack of understanding of causation mechanisms surrounding fatal accidents by electrocution using a systems approach; and there is a disconnection between the mechanism of fatal electrocution accidents and the associated control measures, which may lead to less effective prevention in construction. This dissertation has three objectives, including: (a) establishing a sociotechnical system model that reflects the electrocution occurrence in the U.S. construction industry and identify the associations among its internal subsystems; (b) determining specific electrocution patterns and associated mechanism constraints; and (c) examining hierarchy of control (HOC) measures and determining their appropriateness. Findings from his research include: (a) the identification of three system patterns of electrocution in construction work systems and the associations between personnel, technological, organizational/managerial subsystems, and the internal and external environment for each of the three patterns, using a macroergonomics framework; (b) the identification of five features of work, and map out their decision-making chains, critical decision-making points and constraints, as an interpretation of electrocution mechanisms in the workplace; and (c) revealing that behavioral controls remain prevalent in electrical hazard mitigation even though the knowledge of construction safety and health has increased in the past decades, and that the effectiveness of controls is not statistically different by construction type nor occupation. Based on these findings, the research also suggests corresponding mitigation recommendations that construction managers shall strictly follow HOC rules by giving priority to higher level of controls and upgrading the industry's prevention strategy by introducing more technological innovations and encouraging prevention through design (PtD) strategies.
Ph. D.

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Jönsson, Jack. „Belief-aided Robust Control for Remote Electrical Tilt Optimization“. Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-301028.

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Remote Electrical Tilt (RET) is a method for configuring antenna downtilt in base stations to optimize mobile network performance. Reinforcement Learning (RL) is an approach to automating the process by letting an agent learn an optimal control strategy and adapt to the dynamic environment. Applying RL in real world comes with challenges, for the RET problem there are performance requirements and partial observability of the system through exogenous factors inducing noise in observations. This thesis proposes a solution method through modeling the problem by a Partially Observable Markov Decision Process (POMDP). The set of hidden states are modeled as a high- level representation of situations requiring one of the possible actions uptilt, downtilt, no change. From this model, a Bayesian Neural Network (BNN) is trained to predict an observation model, relating observed Key Performance Indicators (KPIs) to the hidden states. The observation model is used for estimating belief state probabilities of each hidden state, from which decision of control action is made through a restrictive threshold policy. Experiments comparing the method to a baseline Deep Q- network (DQN) agent shows the method able to reach the same average performance increase as the baseline while outperforming the baseline in two metrics important for robust and safe control behaviour, the worst- case minimum reward increase and the average reward increase per number of tilt actions.
Fjärrstyrning av Elektrisk Lutning (FEL) är en metod för att reglera lutningen av antenner i basstationer för att optimera presentandan i ett mobilnätverk. Förstärkande Inlärning (FI) används som metod för att automatisera processen genom att låta en agent lära sig en optimal strategi för reglering och anpassa sig till den dynamiska miljön. Att tillämpa FI i ett verkligt scenario innebär utmaningar, för FEL specifikt finns det krav på en viss nivå av prestanda samt endast en delvis observerbarhet av systemet på grund av externa faktorer som orsakar brus i observationerna. I detta arbete föreslås en metod för att hantera detta genom att modellera problemet som en Delvis Observerbar Markovprocess (DOM). De dolda tillstånden modelleras för att representera situationer där var och en av de möjliga aktionerna behövs, det vill säga att luta antennen upp, ner eller inte ändra på lutningen. Utifrån denna modellering så tränas ett Bayesiskt Neuralt Nätverk (BNN) för att estimera en observationsmodel som kopplar observerade nyckeltal till de dolda tillstånden. Denna observationsmodel används för att estimera sannolikheten att vardera dolt tillstånd är det rätta. Utifrån dessa sannolikheter så görs valet av aktion genom ett tröskelvärde på sannolikheterna. Genom experiment som jämför metoden med en standardimplementering av en agent baserad på ett Djupt Qnätverk (DQN) visas att metoden har samma prestation när det kommer till en medelnivå på prestandaökning i nätverket. Metoden överträffar dock standardmetoden i två andra mätvärden som är viktiga ur aspekten säker och robust reglering, minimumvärdet på prestandaökningen samt medelökningen av prestandan per antal up- och nerlutningar som används.

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Bi, Chong, Congli Sun, Meng Xu, Ty Newhouse-Illige, Paul M. Voyles und Weigang Wang. „Electrical Control of Metallic Heavy-Metal–Ferromagnet Interfacial States“. AMER PHYSICAL SOC, 2017. http://hdl.handle.net/10150/625745.

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Voltage-control effects provide an energy-efficient means of tailoring material properties, especially in highly integrated nanoscale devices. However, only insulating and semiconducting systems can be controlled so far. In metallic systems, there is no electric field due to electron screening effects and thus no such control effect exists. Here, we demonstrate that metallic systems can also be controlled electrically through ionic rather than electronic effects. In a Pt/Co structure, the control of the metallic Pt/Co interface can lead to unprecedented control effects on the magnetic properties of the entire structure. Consequently, the magnetization and perpendicular magnetic anisotropy of the Co layer can be independently manipulated to any desired state, the efficient spin toques can be enhanced about 3.5 times, and the switching current can be reduced about one order of magnitude. This ability to control a metallic system may be extended to control other physical phenomena.

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Doyon, Michel. „Decentralized impedance control“. Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=26384.

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Many applications of manipulators to date have been based on position control, but when a robot manipulator makes contact with the environment, the control of force and position is required. One approach, impedance control, is to control the manipulator such that the relationship between position and force is well defined. For example, such that the robot behaves like a mass-spring-damper system whose parameters can be specified arbitrarily. In the recent years, many of the impedance control implementations were using force feedback from an end-effector force sensor and the impedance control was performed by forming the error in Cartesian coordinates. The implementation proposed here requires instead co-located torque sensors and the feedback control signals are based solely on joint variables, torque and displacement. Co-located torque sensors lead to a larger control bandwidth since the structural dynamics of the arm is seen as a perturbation, but is not part of the plant to be controlled. Simple SISO controllers, designed to modulate individual joint impedances, can achieve diagonal (decoupled) impedance matrices in Cartesian coordinates, provided that a set of SISO compensators, called her "decouplers", are set up to cancel the non-linear coupling among the joints. This strategy results in a simple computational architecture which does not require complex coordinates transformations to be performed at servo rate. The method can be used with non-redundant and redundant manipulators and experimental results are discussed using a seven DOF manipulator available at the Institut de recherche d'Hydro-Quebec.

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Manzoor, Ali, Hesham Elkhbai und Ziad Kkwaneen. „Adaptive Control of Foot Orthosis“. Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-650.

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Major problems of the Foot Drop treatment are expensive and complex solutions. This work

presents the performance of a new inexpensive method named as Semi-Active Ankle Foot

Orthosis (SAAFO). The concept of this approach is to use inexpensive sensors to detect foot step

movement. The signals from the sensors afterwards will be fed to a control system of SAAFO in

runtime for a smooth foot movement of a drop foot patient while walking. Different sensors have

been studied in detail along with comparison to the proposed sensor system and mechanical

design. The signals from the sensors are used to detect different phases of human walking. These

sensors are placed at different positions on an orthosis and their signals are studied in detail.

Experiments have been done in different conditions to get a realistic picture either this assembly

can be implemented commercially. Signals are plotted and discussed yielding that the human

walking phases can be easily and accurately detected using inexpensive sensor assembly.

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Kuditipudi, Sasank. „Simulation for non-congestion losses control over Mobile Ad-Hoc Network using Transmission Control Protocol“. Thesis, California State University, Long Beach, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10007412.

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Mobile Ad-hoc Network (MANET) is a group of individual mobile nodes that exhibit mobility, which results in network congestion. The nodes in MANET are continuously moving with change in network topology that results in significant network congestion. Transmission Control Protocol (TCP) is the most popular connection oriented transport layer protocol used today. The TCP when applied over MANET faces challenges, such as congestion and non-congestion losses. We are concentrating to distinguish between these losses and overcome the non-congestion losses.

The current project presents results on the performance evaluation of various TCP implementations, as measured in terms of the following parameters: end-to-end delay; throughput; network overhead; and packet delivery ratio. Simulations of applying the various TCP schemes over MANET have been performed using the Network Simulator (NS2), and simulation results including comparisons between the different TCP schemes are presented.

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Farson, Dave F. „Control of arc weld thermal cycles“. The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1387446228.

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O'Halek, Stephen J. (Stephen John). „Extending a control system model for rate-based congestion control“. Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/38826.

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Boesak, C. D. „Controller design via H[infinity] optimal control, quantitative feedback theory and fuzzy logic control : an application to load frequency control“. Master's thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/5249.

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Bibliography: leaves 104-112.
This thesis describes the application of robust controller design techniques namely H[infinity] optimal control, fuzzy logic control and quantitative feedback theory to the load frequency control problem of power systems. It thus forms a comparative study of these design methods. Load frequency control is the closed loop control of electrical generating units to regulate the system frequency at its nominal value in the presence of load disturbances. Load frequency control also includes the regulation of the tie-line interchange powers.

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Zhang, Han. „Information Driven Control Design: A Case for PMSM Control“. Cleveland State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=csu1515408555890069.

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Kim, Hana 1980. „Multimodal animation control“. Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/29661.

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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.
Includes bibliographical references (leaf 44).
In this thesis, we present a multimodal animation control system. Our approach is based on a human-centric computing model proposed by Project Oxygen at MIT Laboratory for Computer Science. Our system allows the user to create and control animation in real time using the speech interface developed using SpeechBuilder. The user can also fall back to traditional input modes should the speech interface fail. We assume that the user has no prior knowledge and experience in animation and yet enable him to create interesting and meaningful animation naturally and fluently. We argue that our system can be used in a number of applications ranging from PowerPoint presentations to simulations to children's storytelling tools.
by Hana Kim.
M.Eng.

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Shen, Dennis Ph D. Massachusetts Institute of Technology. „Robust synthetic control“. Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115743.

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Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 63-65).
In this thesis, we present a robust generalization of the synthetic control method. A distinguishing feature of our algorithm is that of de-noising the data matrix via singular value thresholding, which renders our approach robust in multiple facets: it automatically identifies a good subset of donors, functions without extraneous covariates (vital to existing methods), and overcomes missing data (never been addressed in prior works). To our knowledge, we provide the first theoretical finite sample analysis for a broader class of models than previously considered in literature. Additionally, we relate the inference quality of our estimator to the amount of training data available and show our estimator to be asymptotically consistent. In order to move beyond point estimates, we introduce a Bayesian framework that not only provides practitioners the ability to readily develop different estimators under various loss functions, but also equips them with the tools to quantitatively measure the uncertainty of their model/estimates through posterior probabilities. Our empirical results demonstrate that our robust generalization yields a positive impact over the classical synthetic control method, underscoring the value of our key de-noising procedure.
by Dennis Shen.
S.M.

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Yao, Bo 1968. „Priority mechanism for QoS control in CDMA system through dynamic power control“. Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79272.

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Future wireless systems will have to support multimedia services such as voice, data and video. Issues in providing multimedia services on wireless systems include multiple access, bandwidth rationing, scheduling and power control. In this thesis, we address the last issue. CDMA is assumed to be the access method. Each of these services has different Quality of Service (QoS) requirements, maximum power and packet time-out constraints; in order to achieve the required QoS, they can alter their transmission. In this work, we present a novel Power Control With Priority Scheduling (PCWPS) algorithm for a wireless CDMA system, which achieves reliability and efficiently control packet loss due to timeout violation for simultaneously transmitted multimedia traffic, as well as minimizing system total interference. Our power control algorithm requires information about each traffic class instant state, as well as the wireless channel condition at the beginning power update iteration. Based on this information, the optimum allocated power can be calculated through linear or nonlinear programming methods. The simulation results show that our algorithm achieves good performance in term of packet loss due to timeout.

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Jacobs, D. M. (Danver Maxwill). „Voltage control of medium to high power three-phase inverter supply systems“. Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52608.

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Thesis (MScEng)--University of Stellenbosch, 2001.
ENGLISH ABSTRACT: In this thesis a new voltage control method is developed for a three-phase inverter supply system. The inverter supply system consist of a Permanent Magnet Generator, a three-phase rectifier, a three-phase inverter plus LC-filter and a three-phase transformer in series. This system supplies power to a network or to a stand-alone load. The main focus of this thesis is on the control aspects of the inverter and the LC-filter. Different voltage control systems are investigated and compared to each other. From these methods the proposed voltage control method is developed where only the output voltages are measured to establish good voltage control. All these voltage control methods are also simulated with a software package. The proposed voltage control method compares very well with other voltage control methods. The results that are obtained in the simulations are satisfactory. The proposed voltage control method is also implemented in an 8 kW laboratory scale model and, again, very good practical results are obtained. A TMS320F240 nsp controller is used to implement the proposed voltage control method. The controller compensates well for load steps, and these results compare well to an alternative voltage control method, which was also evaluated practically.
AFRIKAANSE OPSOMMING: In hierdie tesis IS 'n nuwe spanningsbeheermetode ontwikkel VIr 'n drie-fase wisselrigter kragtoevoerstelsel. Die wisselrigter kragtoevoerstelsel bestaan uit 'n Permanent Magneet Generator, 'n drie-fase gelykrigter, 'n drie-fase wisselrigter plus Le-filter, en 'n drie-fase transformator in serie. Hierdie stelsel voorsien krag aan 'n netwerk sowel as aan 'n alleenstaande las. Die hooffokus van hierdie tesis is op die beheeraspekte van die wisselrigter en Le-filter. Verskillende spanningsbeheermetodes is deeglik ondersoek en vergelyk met mekaar. Uit hierdie metodes is dan die voorgestelde beheermetode ontwikkel waar slegs die uittreespanning gemeet word om goeie spanningsbeheer te kan doen. Al hierdie spanningsbeheermetodes is dan gesimuleer met 'n sagteware pakket. Die voorgestelde spanningsbeheermetode vergelyk baie goed met die ander spanningsbeheermetodes. Die resultate verky in die simulasies is ook baie bevredigend. Die voorgestelde beheermetode is ook geïmplementeer op 'n 8 kW laboratorium skaalmodel en weereens is baie goeie praktiese resultate verky. 'n TMS320F240 DSP-beheerder is gebruik om die voorgestelde beheermetode mee te implementeer. Die beheerder kompenseer baie goed vir lastrappe en vergelyk ook goed met 'n ander spanningsbeheermetode wat prakties ge-evalueer is.

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Alvarez, Rogelio E. „Interdicting electrical power grids“. Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Mar%5FAlvarez.pdf.

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Thesis (M.S. in Operations Research)--Naval Postgraduate School, March 2004.
Thesis advisor(s): Javier Salmeron, R. Kevin Wood. Includes bibliographical references (p. 69-70). Also available online.

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Khairallah, Ousama Said. „Robotics Control using Active Disturbance Rejection Control“. Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1262832204.

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Tipsuwan, Yodyium. „Gain Scheduling for Networked Control System“. NCSU, 2003. http://www.lib.ncsu.edu/theses/available/etd-08282003-105850/.

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Performances of closed-loop control systems operated over a data network are typically degraded by network-induced delays. Furthermore, the closed-loop control systems can become unstable. The purpose of this research has been to develop a control methodology to handle network-induced delay effects using optimal gain scheduling on existing controllers. The proposed gain scheduling technique adapts controller gains externally by modifying a controller output to enable the controller for uses over a data network. Since existing controllers can still be utilized, the proposed methodology can reduce control system reinstallation and replacement costs. First, the effectiveness of the proposed gain scheduling technique on networked DC motor speed control using a PI (Proportional-Integral) controller is investigated. Also, the concept of network traffic condition measurement to select optimal controller gains is presented. Then, a middleware framework to measure network traffic conditions on an IP network based on delays and delay variations and to modify controller gains is described. Suggestion of using neural network in the gain scheduling scheme is also given. Finally, the gain scheduling technique with the middleware framework is then extended to mobile robot path-tracking control.

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Kavuru, Sree Keerthi. „Vital sign monitor with emergency control“. Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1603974.

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Negligence of the health care representatives during emergency situations causes numerous deaths in the hospitals. Developing an efficient, quick and reliable health care monitor with emergency control can help reduce human errors. This project is based on monitoring patients admitted in hospitals. It is a health monitoring device which measures the heart rate, blood pressure and body temperature of patients. After the vitals are measured accurately, it transmits them wirelessly to a monitoring room using ZigBee. In emergency situations, abnormal vitals are sent to the doctor and the emergency contact using a GSM module. There are many monitoring systems using Bluetooth, but monitoring using ZigBee has many advantages. There is a new approach by adding a GSM module, as the vitals can be received on any telephone as a SMS. This is very useful when they need to be sent to an emergency contact or the doctor in charge. This elementary, cost efficient health monitoring system is based on a simple controller. The main result achieved by this approach is the reduction of the micro controller processing time by twelve, due to which the end to end execution time of the system is also reduced. The heart rate of the patient is also measured with medically approved equipment unlike the previous models.

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Alsaif, Saif A. „Echoic Flow for Guidance and Control“. The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1543864969419357.

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Yorke, Rory. „Chaos control using local polynomial approximation“. Master's thesis, University of Cape Town, 2001. http://hdl.handle.net/11427/5075.

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Includes bibliographical references.
Chaotic systems may be defined as those whose behaviour is sensitively dependent on initial conditions. Such systems may be made periodic using small input perturbations, as proposed in [OGY90]; this is called Ott-Grebogi-Yorke (OGY) chaos control. The original method used a linear model for controller design; a later development of chaos control was [CCdF99], in which a polynomial model is used. This dissertation proposes using local Taylor polynomial models as a basis for chaos control.

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Marques, Fausto. „The robustness of H-infinity control“. Master's thesis, University of Cape Town, 1999. http://hdl.handle.net/11427/16094.

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Bibliography : leave 111.
Modern control theory generates controllers of a high order. Since these controllers inherently require elaborate circuits or algorithms for implementation, there is always the possibility that the implemented controller will differ from the designed controller by a certain degree. Furthermore, the control engineer might want to tweak the controller in practice and will therefore deliberately adjust the parameters of the nominal controller. The key factor is that the controller although perturbed from the nominal controller, will still stabilize the closed loop system. The greater this perturbation can be without destabilizing the closed loop system, the more robust the controller is. Keel et al, in their paper entitled "Robust, Fragile or Optimal?" (1997), made a statement that the controllers generated by H-infinity design methods are fragile. A norm was introduced called the parametric stability margin, to serve as a measure of this robustness. A fragile controller is defined as a controller that is very sensitive to changes in its controller coefficients and any small change from the nominal controller will result in closed loop instability. This type of controller will have a very small parametric stability margin. This parametric stability margin is defined as a radius in parameter space in which the controller will be stable in closed loop. If the norm of the perturbation exceeds this margin in parameter space, then the closed loop system will become unstable. A real plant was chosen as a means to test the claims of Keel et al. The plant is a simple "robot arm", a non-linear second order system. The non-linearity creates both open loop stable and unstable regions for control. A controller was designed for this plant using H-infinity techniques. This controller would form the basis for testing the claims of Keel et al. When this controller was analysed using the parametric stability margin, it was predicted to be fragile or stated differently: very small changes in the controller coefficients would destabilize the closed loop system. However, closer scrutiny revealed that this sensitivity was only concentrated on the leading coefficients in the numerator and denominator of the controller. Furthermore, the relative size of the perturbations on these coefficients was far in excess of 1000% of the original coefficient. The designed controller was implemented successfully in practice using a digital implementation. Even a perturbed version of 200% of the controller coefficients stabilized the closed loop system. It was then discovered that it was possible to create a perturbation with a norm greater than the parametric stability margin that would still stabilize the closed loop system. A similar perturbation could also be constructed for the examples presented by Keel et al in their paper (1997). The resulting conclusion was that the H-infinity techniques actually generate rather robust controllers. Provided that the perturbations on the leading controller coefficients are kept below the destabilizing value, the other coefficients can be perturbed to a very large degree. This destabilizing value is given by the perturbation vector at the parametric stability margin. This perturbation will place some closed loop poles on the stability boundary of the region of interest.

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