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1
Soviš, Jiří. „Bezsnímačové řízení střídavých motorů na platformě STM32“. Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442463.
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The thesis is focused on the issue of sensorless vector control of a synchronous motor with permanent magnets in the low-speed range. In the first part, there is a brief description of the synchronous motor and the necessary transformations for the application of vector control. This is followed by the overview of sensorless methods for position estimation by injecting a high-frequency harmonic signal. The practical part is devoted to the implementation of a control algorithm to develop kit STM32NUCLEO-L476RG, which is preceded by the identification of all engine parameters. As part of the implementation, a structure including current, speed and position control was designed. The functionality and robustness of the settings have been successfully tested due to the different inertia and load.
2
Cilia, Joseph. „Sensorless speed and position control of induction motor drives“. Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362888.
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3
Östling, Johan. „High Accuracy Speed and Angular Position Detection by Dual Sensor“. Thesis, Uppsala universitet, Fasta tillståndets fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-365726.
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For many decades there has been a need in many industries to measure speed and position of ferrous gears. This is commonly done by converting passing gear teeth from trigger wheels to electrical impulses to calculate speed and angular position. By using Hall effect sensors or Giant Magnetoresistance sensors (GMR), a zero speed detection of gear teeth is possible while at the same time be cheap to produce and durable for harsh environments. A specially designed trigger-wheel (cogwheel created for measurements) with gear teeth in a specific pattern, exact position can be detected by using a dual sensor, even when no earlier information is available. The new design of trigger-wheel also makes this new method more accurate and universal compared to previous solutions. This thesis demonstrates and argues for the advantages of using a dual sensor for speed and angular position detection on gear wheels. Were one sensor do quantitative measurements for pattern detection in the teeth arrangements and the other sensor do qualitative measurements for position detection.
4
Budden, Alan Stephen. „Sensorless zero-speed position detection for brushless permanent magnet machines“. Thesis, University of Bristol, 2006. http://hdl.handle.net/1983/05c6fe86-20a7-4a40-b39d-4f62d0c774a7.
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5
Rao, Niankun. „A novel high-speed stereo-vision system for real-time position sensing“. Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/39637.
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Real-time position sensing has a wide range of applications in motion control systems, parts inspection
and general metrology. Vision-based position sensing systems have significant advantages over other
sensing methods, including large measurement volume, non-contact sensing, and simultaneous mea-
surement in multiple degrees-of-freedom (DOF). Existing vision-based position sensing solutions are
limited by low sampling frequency and low position accuracy. This thesis presents the theory, design,
implementation and calibration of a new high-speed stereo-vision camera system for real-time position
sensing based on CMOS image sensors.
By reading small regions around each target image rather than the full frame data of the sensor,
the frame rate and image processing speed are vastly increased. A high speed camera interface is
designed based on Camera Link technology, which allows a maximum continuous data throughput
of 2.3Gbps. In addition, this stereo-vision system also includes fixed pattern noise (FPN) correction,
threshold processing, and sub-pixel target position interpolation.
In order to achieve high position accuracy, this system is calibrated to determine its model parame-
ters. The primary error sources in this system include target image noise, mechanical installation error
and lens distortion. The image sensor is characterized, and its FPN data is extracted, by experiment.
The mechanical installation error and lens distortion parameters are identified through camera cali-
bration. The proposed camera calibration method uses the 3D position reconstruction error as its cost
function in the iterative optimization. The optimization of linear and nonlinear parameters is decoupled.
By these means, better estimation of model parameters is achieved. To verify the performance of the
proposed calibration method, it is compared with a traditional single camera calibration method in sim-
ulation and experiment. The results show that the proposed calibration method gives better parameter
estimation than the traditional single camera calibration method.
The experimental results indicate that the prototype system is capable of measuring 8 targets in 3-
DOF at a sampling frequency of 8kHz. Comparison with a coordinate measurement machine (CMM)
shows that the prototype system achieves a 3D position accuracy of 18μm (RMS) over a range of
400mm by 400mm by 15mm, with a resolution of 2μm.
6
Chi, Song. „Position-sensorless control of permanent magnet synchronous machines over wide speed range“. Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1186974583.
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7
Roskilly, Kyle. „Sensor augmentation of GPS for position and speed sensing in animal locomotion“. Thesis, Royal Veterinary College (University of London), 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.669198.
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8
Chretien, Ludovic. „POSITION SENSORLESS CONTROL OF NON-SALIENT PERMANENT MAGNET SYNCHRONOUS MACHINE“. University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1145286531.
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9
Chan, Leon Y. (Leon Yen-Lee). „Mechanisms of regulation of the spindle position checkpoint kinase, Kin4“. Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/58197.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references.
Most cells are polarized in that they are aware of spatial cues and can respond to these cues accordingly. One major aspect of cell function that is often responsive to these polarization cues is cell division. Cell division, the process of making two cells from one progenitor, requires equal distribution of the genetic material to the two progeny cells. When polarized cells divide, an additional constraint on the segregation of the genetic material is imposed, namely, cells must divide the genetic material along axes defined by polarization cues. In eukaryotes, this problem is generally solved by the positioning of the mitotic spindle according to these spatial cues. Defects in spindle positioning can lead to the generation of cells with incorrect organelle, genetic and molecular contents, fate and/or, spatial orientation. Cells have evolved feedback mechanisms that monitor defects in spindle positioning and delay the cell cycle in response to such defects. These mechanisms are best elucidated in the budding yeast, Saccharomyces cerevisiae. The protein kinase Kin4 inhibits the Mitotic Exit Network when the spindle is mis-positioned. How Kin4 is itself regulated and whether or how Kin4 responds to spindle mis-position is not known. The work presented in this thesis elucidates the regulation of Kin4. We identify a novel spindle position checkpoint component, PP2A-Rts 1, and show that it promotes checkpoint function by enabling proper Kin4 localization. We also identify domains and sequence determinants within Kin4 that control localization and function. We present a model of how the spindle position checkpoint senses spindle position and test this model for Kin4 function. We find that the generation of positive and negative mitotic exit regulatory zones allows the cell to sense and translate the spatial information of spindle position into a chemical cell cycle signal.
by Leon Y. Chan.
Ph.D.
10
Myers, Paul G. „A two-dimensional spoiler of arbitrary chordwise position in a low speed flow“. Thesis, University of Bristol, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303755.
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11
Alamaa, Angelica. „High-speed railway embankments : a comparison of different regulation“. Thesis, KTH, Jord- och bergmekanik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-198074.
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Swedish transport administration initiated this Master Thesis project and the aim was to compare regulations for the design of high-speed railways from three European countries: France, Germany and Spain. The reason why this is of interest for the Swedish transport administration is the design of the first Swedish high-speed railway, called Ostlänken. Therefore, a literature study of the regulations and other literature regarding high-speed railway has been carried out. A basic description of railway components, slab track and ballasted tracks is presented. Ballasted embankments usually consist of a trackbed layer (ballast onto subballast), and the ultimate thickness of this layer is discussed, as there are a number of methods available to calculate the appropriate thickness, with a number of different design parameters. These design methods results in different trackbed thickness and choosing the “wrong” method might lead to an overestimation or underestimation of the trackbed layer. Constructing a ballastless railway line means that the ballast is replaced by another material, usually a slab made of reinforced concrete or asphalt, and the rail is cast onto this slab. Countries design their slab using different methods. Germany has constructed high-speed railway lines with a slab track solution, generally slabs with low flexible stiffness. France has until recently constructed their high-speed line ballasted but is now developing a new slab track technique, called NBT (New Ballastless Track) and Spain uses various methods. It is difficult to compare the regulations, however, there are some factors that at least begin to explain the differences between the countries: the frost hazard, the inherent ground quality, purpose with the railway (mixed traffic, solely passenger traffic, etc.), design parameters (life, axle load, etc.). Furthermore, the settlement requirements, soil classification and bearing capacity are factors that varies from country to country, but the origin for this variation is harder to detect.
12
Winter, Alexei Ivan. „Speed regulation for tidal turbines : a new control concept“. Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.723430.
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13
Keysan, Ozan. „A Non-invasive Speed And Position Sensor For Induction Machines Using External Search Coils“. Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/3/12610290/index.pdf.
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In industrial drives market, speed and position estimation are one of the most important subjects for accurate motor drives. Vector controlled drives has the best dynamic performance among AC motor drives. Sensorless vector control is one of
the most studied one. However, sensorless drive systems fail at low or zero speeds and may not have enough accuracy. For better accuracy and speed range speed sensors or position encoders are usually essential. However, coupling of sensor and
sensor prices introduces extra cost on the drive. Thus in order to reduce the cost of the drive a cheap and easy to mount speed sensor is essential.
Throughout this study, a speed and position sensor using an external search coil placed between cooling fins on the frame of an induction machine is proposed. The search coil utilizes the fringing flux outside the frame of induction motor. Using
the induced voltage on the external search coil, a new method that estimates the flux and rotor position is proposed.
In this study, the induced voltage on the search coils are investigated with different types of search coils placed on various positions. The frequency domain and time domain analysis are performed in order to build a model that can estimate machine flux, rotor speed and rotor position.
As a result of this study, a low cost, easy to mount speed and position sensor is designed and implemented. Experiment results are presented.
14
Irigoyen, Eizmendi Javier. „Commande en position et force d'un robot manipulateur d'assemblage“. Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb37598444q.
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15
Gogas, Kyriakos. „Design of a robust speed and position sensorless decoupled P-Q controlled doubly-fed induction generator for variable-speed wind energy applications“. Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99762.
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Wind energy is a relatively young but rapidly expanding industry. In order for wind generation to be cost effective, it must produce energy at a minimum cost per dollar of investment. Performance characteristics such as power output versus wind speed must be optimized in order to compete with other energy sources. Also, if the utility uses wind power for a part of its generation, the output power of these turbines must have the same high quality and reliability when it enters the utility grid. The ability to vary operating speed is important in wind generation because it allows for an optimization of the transfer of power from the wind to the turbine shaft. Doubly-fed induction generators (DFIG) are an interesting solution for variable-speed systems with limited variable speed range, and are typically used in wind energy conversion systems.The objectives of this thesis are to implement a decoupled P-Q control of a DFIG that does not rely on mechanical sensors and to design a speed and position sensorless algorithm that is robust to variations of the values of the machine parameters. The sensorless DFIG control algorithm presented in this thesis is based on a modified phasedlock loop with an improved positioning algorithm. With the measured stator voltages, stator and rotor currents, the speed and position of the DFIG are estimated. The speed is estimated independent of machine parameters, which results in a significant improvement in speed control robustness to parameter variations. In addition, the algorithm avoids using differentiation, which significantly improves its immunity to noise and does not require the measurement of the rotor voltages. Also, it is shown that the positioning algorithm has an improved operation in generator mode. Although the accuracy of the positioning algorithm is depended on machine parameters; it is shown with the designed controller that the P-Q decoupled control is robust to changes of machine parameters. Theoretical and simulation results are validated on an experimental setup.
16
Vickery, John Lawrence. „AN INTELLIGENT DIFFERENCING GLOBAL POSITIONING SYSTEM UTILIZING DIFFERENTIAL DOPPLER TO DETERMINE POSITION AND SPEED ACCURATELY“. MSSTATE, 2002. http://sun.library.msstate.edu/ETD-db/theses/available/etd-03012002-121541/.
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It is not where in the world you are that matters. It is where you are with respect to a reference point whether on land or at sea. That is the basis behind Differencing GPS. Utilizing the carrier wave and Gold Code (GC) signal transmitted by GPS satellites, this project uses two GPS receivers and a system integration manager utilizing neural networks and expert systems to determine a user position and speed relative to a fixed point on earth. Two methods of determining the user position are employed: classic triangulation and measuring the difference in the Doppler shift of the carrier wave between the user and the reference receiver. The idea is for the user to know where they are in relationship to a designated fixed point and navigate with respect to that fixed point. The user could range from a farmer or an aircraft out at sea attempting to land on the deck of a carrier.
17
Bu, Jianrong. „High performance rotor position sensorless control of switched reluctance machines over a wide speed range /“. The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487949836205613.
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18
Zhuan, Xiangtao. „Optimal handling and fault-tolerant speed regulation of heavy haul trains“. Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-07212007-131319.
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19
Lee, Jae Ryong. „Microprocessor-based soft variable structure control for D.C. motor speed regulation“. Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/50045.
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The theory of soft variable structure control, which produces robustness to parameter variation and fast transient response, is discussed in this thesis.
The digital implementation techniques are presented in the aspects of sample rate, prefilter design, hardware selection, and microprocessor arithmetic operation.
Simulation and experimental results showed good performance in negative speed range, but this controller created unwanted high armature current fluctuation in positive speed range. The reasons turned out to be the limitation of sample rate, noise from the tachometer, and high gain at positive speed.Master of Science
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20
Mehta, Urmish R. „Optimal control of a high speed overhead crane including hoisting“. Ohio : Ohio University, 1992. http://www.ohiolink.edu/etd/view.cgi?ohiou1172863064.
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21
Boukas, Theocharis K. „Exact feedback linearization with state derivative feedback for high-performance field-oriented induction motor speed/position control“. Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/14890.
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22
Webster, Courtney Ann. „Effects of Running Speed, Fatigue, and Bracing on Motor Control of Chronically Unstable Ankles“. Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23733.
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Ankle sprains are among the most common injuries for participants in running and jumping sports. Following an initial sprain injury, many (30-40%) will develop chronic ankle instability (CAI), characterized by a perception of instability and repeated sprain injuries. Quasi-static test methods indicate poor postural stability and joint position sense (JPS) as associated motor control deficits. Little research, though, has investigated ankle motor control under dynamic (simulated sport) or fatigue conditions. To better understand factors contributing to the increased sprain rate in adults with CAI, three studies were completed investigating the roles of running speed, fatigue, and ankle bracing on motor control in adults with CAI.
First, two groups with and without ankle instability performed dynamic athletic maneuvers at each of two running speeds. Joint kinematics and kinetics were measured to identify differences in motor control strategies. Participants also completed two quasi-static tests (JPS and single leg drop landings). The level of correspondence between quasi-static and dynamic test methods was of particular interest. A second study compared fatigue development and fatigue adaptations when executing single leg drop landings. Strength loss and ratings of perceived exertion measured fatigue development, and joint kinematics, kinetics, and muscle activation quantified drop landing performance. A final study examined whether ankle braces, a common treatment for ankle sprains, retained their effectiveness when an athlete was fatigued. JPS and ankle stiffness were measured before and after a fatigue protocol while using each of three brace conditions.
Overall, results indicated that adults with CAI exhibit distinct adaptations to changes in speed and to fatigue that may increase their risk for ankle reinjury. Specific changes, however, depended on the particular activity being performed. Single leg drop landing kinematics may be a good representation of kinematics during dynamic athletic performance. Neither test brace improved JPS following fatigue, but each may be effective in providing mechanical stiffness compared to an unbraced condition. The effectiveness of a particular test brace, however, may be gender-specific. Future work should focus on identifying the benefits of different braces under broader conditions to help inform brace selection.Ph. D.
23
Page, Karen Mary. „Mathematical models in embryology : the selection, regulation and speed of formation of patterns“. Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302119.
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24
Bennett, April M. „Active Regulation of Speed During a Simulated Low-altitude Flight Task: Altitude Matters!“ Wright State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=wright1167238078.
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Ofori, Ernest. „A Pulse Injection Based Sensorless Position Estimation Method for a Switched Reluctance Motor over a Wide Speed Range“. University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1403130339.
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26
Meadows, John Ceil. „Regulation of mitotic progression by factors that influence spindle position and stability in fission yeast“. Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1444825/.
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It has previously been proposed that in fission yeast mitotic spindle position is monitored by a checkpoint that controls the timing of anaphase onset. This checkpoint is activated by treatment of cells with Latrunculin A (Lat A), an inhibitor of actin polymerisation. It was previously thought that Lat A imposes an anaphase delay by preventing interaction of astral microtubules with the cortical actin cytoskeleton and that this interaction was required for correct spindle orientation. By contrast I show that cells lacking Mto1, a centrosomin-like protein, have mis-orientated spindles but are not delayed in the timing of sister chromatid separation. Secondly, I show that astral microtubules are only nucleated after sister chromatids separate and that mitotic spindle orientation is instead determined by the position of the spindle pole body during interphase. Spindle pole position is controlled by interphase microtubules, which also position the nucleus in the centre of the cell. Since the position of the nucleus determines the site of septation, I propose that interphase microtubules ensure perpendicular alignment of the spindle and the axis of cell division. Thirdly, in contrast to previous findings, I find that Lat A causes an anaphase delay and mitotic spindle collapse in a proportion of cells. These results suggest that Lat A delays the onset of anaphase by disrupting mitotic spindle stability rather than by causing spindle mis-orientation. Importantly, this effect is abolished in a Lat A-insensitive actin mutant, implicating a role for actin in mitotic spindle stability. Lastly, I demonstrate that the effect of Lat A is exacerbated in cells lacking Ase1, which binds and stabilises the spindle midzone. I have uncovered two factors, Mal3, and a novel kinesin, Klp9, which are required for viability in the absence of Ase1. I present a preliminary characterisation of the role of Klp9 in the mitotic cell cycle.
27
Festenstein, Richard. „Molecular analysis of the human CD2 Locus Control Region in transgenic mice“. Thesis, Open University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321311.
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28
March, Philip. „Robust anti-windup control and its application to permanent magnet synchronous motor speed regulation“. Thesis, University of Leicester, 2009. http://hdl.handle.net/2381/27563.
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This thesis is concerned with the design of anti-windup compensators and similar augmentations to electronic control systems that aid the system to cope with isolated nonlinearities within the closed loop such as actuator saturation. The thesis builds on theoretical contributions in the literature regarding the synthesis of low order dynamic anti-windup compensators by presenting a successful industrial application of these techniques. A range of other anti-windup techniques are described and through simulation and mathematical analysis, the pros and cons of these designs are presented. Some subtle extensions to the recent optimal synthesis routines are also presented that can offer improved flexibility in tuning and greater performance for certain systems. The industrial application chosen is an Electrically Powered Hydraulic Steering (EPHS) system in which complex constraints are applied to the currents flowing in and voltages applied to a three phase Permanent Magnet Synchronous Motor (PMSM) contained within.
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Becker, Jeremie Francois Claude. „Determinants of nucleosome organisation and transcription regulation by histone marks“. Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:b91fc973-2eb5-4e76-b6d5-ddaed1449a68.
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Epigenetics is the study of heritable changes in gene expression that do not involve changes in the underlying DNA sequence. Epigenetic pathways appeared in eukaryotes where multicellular organisms differentiate into different cell types, associated with different phenotypes. The differentiation process is achieved by modifications of the chromatin structure which, by altering the access of trans-factors to the DNA, result in gene activation and repression. Epigenetic mechanisms are therefore viewed as an "extra" layer of information that modulate the genetic information in time and space, necessary for the development and the response to environment stimuli. Although the recent development of high-throughput sequencing technologies has provided an unprecedented insight into epigenetic pathways, the mechanisms controlling the chromatin dynamic as well as their downstream effects on cellular processes are far from being fully understood. In this thesis, our focus will be restricted to mechanisms acting on the nucleosome level. The first chapter will present the factors known to influence nucleosome positioning as well as the challenges related to the measurement of the nucleosome architecture. The second chapter will introduce a statistical approach, NucleoFinder, capable of identifying nucleosomes consistently positioned in a population of cells. In chapter three, we will make use of NucleoFinder to investigate the importance of cis and trans-factors on the nucleosome architecture in human and show that, despite variation across functional regions, cis-factors have a very modest in influence on nucleosome positioning. Finally, in chapter four, we will aim to identify clusters of histone modifications specific to functionally distinct regions, characterize their function and their association with gene expression level.
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Sutter, Nathaniel Barrett. „Suppression of stable and variegating position effects by the 5'HS2 and inducible 3MRE enhancers /“. Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/5038.
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Zuleta, Ignacio. „A high speed mass spectrometer based on micromachined ion optics and position sensitve detection for the monitoring of non-stationary processes /“. May be available electronically:, 2008. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
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Messali, Amir. „Contribution to Rotor Position and Speed Estimation for Synchronous Machine Drive Using High Frequency Voltage Injection : Application to EV/HEV Powertrains“. Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0048.
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Cette thèse s’inscrit dans le cadre de la chaire Renault/Centrale Nantes sur l’amélioration des performances des véhicules électriques (EV/HEV). Elle est dédiée à la problématique de l’estimation de la position/vitesse des moteurs synchrones à aimants permanents (MSAP) sans capteur mécanique, en utilisant les techniques d’injection de signaux haute fréquence (HF) sur toute la plage de vitesse des MSAP. Dans ce cadre, plusieurs contributions ont été proposées dans les parties de démodulation/traitement du signal et d’algorithmes de poursuite des techniques d’injection HF, afin d’améliorer l’estimation de la position/vitesse des MSAP par rapport aux méthodes existantes. Dans la partie démodulation/traitement du signal des techniques d’injection HF, les contributions ont consisté à proposer des solutions originales permettant de réduire les effets de filtrage dans la chaine d’estimation et de rendre cette dernière indépendante des paramètres (électriques) de la machine. Dans la partie poursuite, les contributions portent essentiellement sur l’exploitation de la fonction signe de l’erreur de position (à la place de l’erreur de position) comme information de mesure, pour estimer la position, la vitesse et l’accélération des MSAP sans capteurs mécaniques avec des observateurs par modes glissants d’ordre 1 (classiques, étapes par étapes et adaptatifs). Les contributions proposées dans les deux parties ont pour avantages d’une part, de robustifier la chaine d’estimation en la rendant indépendante des paramètres électriques et mécaniques. Et d’autre part, d’améliorer la précision et les performances de la chaine d’estimation, et par conséquent du contrôle des MSAP sans capteurs mécaniques, dans les phases transitoires et en régimes permanents avec une méthode de réglage aisée. Les méthodes d’estimation développées ont été testées en simulation et en expérimentation sur un banc d’essai de machines électriques. Les résultats obtenus ont permis de mettre en évidence les performances de ces méthodes en terme de suivi de trajectoire et de robustesse sur toute la plage de fonctionnement des MSAP sans capteurs mécaniquesThis thesis is part of the Renault / Centrale Nantes Chair on improving the performance of electric vehicles (EV / HEV). It is dedicated to the problem of estimating the position / speed of self-sensing permanent magnet synchronous motors (PMSM) without mechanical sensors, using high frequency (HF) signal injection techniques over the full speed range of PMSM. In this context, several contributions have been proposed in the demodulation / signal processing and tracking algorithms parts of HF injection techniques, in order to improve the estimation of the position / speed of the MSAP compared to the existing methods. In the demodulation / signal processing part of the HF injection techniques, the contributions consisted of proposing original solutions making it possible to reduce the filtering effects in the estimation chain and to make the latter independent of the electrical machine parameters. In the tracking part, the contributions mainly concern the use of the function sign of the position error (instead of the position error) as measurement information, to estimate the position, the speed and the acceleration of self-sensing PMSM with firstorder sliding mode observers (conventional, step-by-step and adaptive). The contributions proposed in both parts have the advantages of robustifying the estimation chain by making it independent of electrical and mechanical parameters on the one hand. On the other hand, they allow improving the accuracy and performance of the estimation chain, and therefore the control of self-sensing PMSM, in transient and steady-state phases with an easy tuning method. The estimation methods developed were tested in simulation and experimentation on a test bench of electrical machines. The results obtained made it possible to highlight the performances of these methods in terms of trajectory tracking and robustness over the entire operating range of PMSM self-sensing control
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Corrales, Berjano Marc 1984. „Text in context : Chromatin effects in gene regulation“. Doctoral thesis, Universitat Pompeu Fabra, 2018. http://hdl.handle.net/10803/565719.
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This thesis reports the study of chromatin composition and conformation on the expression of integrated reporters at thousands of genomic locations in the Drosophila genome. We have adapted and improved a technology (Thousands of Reporters Integrated in Parallel TRIP) to randomly integrate barcoded reporters allowing us to measure the context effects on transcription at ~80.000 different loci. We have focused on housekeeping promoter-reporters due to their relative autonomy from distal regulatory elements.
Taking advantage of published genome-wide localization maps of chromatin protein and histone marks, together with the three-dimensional genome structure of the Drosophila Kc167 cell line, we have been able to computationally extract the features that best predict the expression of the integrated reporters. Centromeric heterochromatin is highly silencing but position effects were also observed along chromosome arms, away from heterochromatin. Chromatin states such as Black and Blue (Polycomb, H3K27me3) were found to be refractory to expression while Green (HP1, H3K9me) was found to be permissive or refractory depending on the location. Yellow (MRG15, H3K4me) chromatin was the most permissive while Red (Brm, H3K4me) could also be repressive or activating depending on the integration point.
Surprisingly we discovered that the housekeeping reporters are maximally expressed when they land on loci engaging in contacts with promoters and terminators of active genes.
The low dependence on enhancers confirms the hypothesis that the requisites for developmental regulation are different that for broadly expressed genes.
Moreover our results bring experimental evidence to the observation that housekeeping genes tend to cluster during evolution along the chromatin fiber, providing an explanation to the spatial contacts among these clusters observed in Hi-C experiments.Esta tesis recoge los resultados del estudio del efecto de la composición y conformación de la cromatina en la expresión génica mediante la integración de miles de reporteros en el genoma de Drosophila. A tal efecto hemos adaptado y mejorado una técnica (Thousands of Reporters Integrated in Parallel, TRIP) permitiendo la integración aleatoria de genes reportero marcados (barcoded) con el fin de medir su expresión dependiente de contexto en ~80.000 loci distintos. Gracias a los numerosos mapas de ocupación a escala genómica de proteínas asociadas a cromatina y marcas de histonas, así como la estructura tridimensional del genoma en la linea celular utilizada Drosophila Kc167, hemos podido extraer las variables que mejor explican la expresión de los genes reportero integrados. La Heterocromatina pericentromérica demostró su capacidad represora aunque los efectos de posición también pudieron observarse en los brazos cromosómicos, lejos de dicha cromatina. Estados de la cromatina como Black y Blue (Polycomb, H3K27me3) se mostraron refractarios a la expresión mientras que la de tipo Green (HP1, H3K9me) demostró tener efecto ambivalente en función del lugar de integración. La cromatina Yellow (MRG15, H3K4me) mostró ser la mas permisiva mientras que la de tipo Red (Brm, H3K4me) evidenció el mismo carácter ambivalente en función del punto de integración. Sorprendentemente descubrimos que los reporteros housekeeping se expresan de forma óptima cuando se integran en loci contactando promotores y terminadores de genes activos. La escasa dependencia de enhancers confirma la hipótesis según la cual los requisitos para la regulación de genes del desarrollo difieren de los utilizados por genes de expresión ubicua. Por ultimo nuestros resultados brindan evidencia experimental a la observación de la agrupación de genes housekeeping a lo largo de la fibra de ADN durante la evolución. De mismo modo aportan una explicación para el elevado numero de contactos que muestran dichas agrupaciones en experimentos Hi-C.
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Elkhomri, Othman. „DSP IMPLEMENTATION OF DC VOLTAGE REGULATION USING ADAPTIVE CONTROL FOR 200 KW 62000 RPM INDUCTION GENERAT“. Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2926.
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The thesis discusses the development of closed loop system to control the DC voltage for 200 kW induction generator rated at a speed of 62000 RPM under different load conditions. The voltage regulation has been implemented using PI controller. A gain scheduling control algorithm has been developed to select the appropriate controller gains with respect to the generator load. Further, a relationship between the generator loads and the controller gains has been established. This relationship has been modeled using adaptive control technique to vary the gains automatically at any load condition. The adaptive control technique has been successfully generalized for real time DSP implementation to regulate the DC voltage for high speed induction generators rated from 5 kW to 200 kW.M.S.
Department of Electrical and Computer Engineering
Engineering and Computer Science
Electrical Engineering
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Lalonde-Parsi, Marie-Jasmine. „Perception of self-motion & regulation of walking speed in older adults in comparison to young adults“. Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=117015.
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Older adults display slower walking speeds, which could be attributed to an altered perception of optic flow (OF) speed. It has been previously demonstrated that older adults exhibit altered speed discriminations when exposed to expanding OFs. Whether these perceptual impairments explain slower and less context-adapted gait speeds in older adults remains unknown. The purpose of this study was to contrast speed discrimination thresholds and gait speed adaptations in young-old vs. younger adults. I also sought to determine whether speed discrimination and walking speed modulation abilities were related in older adults. Twelve young adults (23.0 ± 2.4 years) and twelve young-old adults (68.8 ± 4.4 years) participated in a speed discrimination experiment and two walking experiments. In the speed discrimination experiment, participants wore a head-mounted display (HMD) that displayed a virtual reality (VR) scenario depicting self-motion along a corridor. Participants were asked to choose which of two scenes that were played sequentially, moved faster. Speed discrimination thresholds were determined as the geometric mean of the last eight reversals. In the walking tasks, participants walked on a self-paced treadmill while wearing the HMD and viewing the VR scene showing OF speeds ranging from 0.25 to 2 times their comfortable speed. In the first walking paradigm, participants were instructed to walk the corridor distance of each test trial, which displayed different OF speeds, within the same time as during a preceding control trial that presented an OF matching their comfortable gait speed. In the second walking paradigm, participants were instructed to match their gait speed to the speed of the OF shown in the virtual environment. Walking speed modulation was measured as the slope between walking speed changes and OF speed changes (walking paradigm 1), and as the absolute error in walking speed with respect to the target speed (walking paradigm 2). Older adults showed larger speed discrimination thresholds, more attenuated slopes and larger errors in speed compared to their younger counterpart. Within the older group, speed discrimination thresholds were not significantly related to speed modulation abilities, as measured by the slopes and absolute errors in speed. These findings indicate that older age affects both the ability to perceive speed information from OF and to modulate walking speed in response to OF speed changes. It is suggested that poor visual motion perception may be one of the contributing factors leading to a mobility decline in older adults.Les gens âgés ont une démarche plus lente, ce qui peut être attribué à une perception fautive de la vitesse du flux optique (FO). Il a déjà été démontré que les personnes âgées ont une capacité altérée à discriminer la vitesse de stimuli visuels décrivant des FO à différentes vitesses. On ne sait toujours pas si cette perception déficiente explique que leur vitesse de marche soit plus lente et que leur démarche soit moins adaptée aux demandes contextuelles. Le but de cette étude était de comparer le seuil de discrimination de la vitesse et l'adaptation de la vitesse de marche chez des jeunes personnes et des personnes âgées en bonne santé. J'ai aussi examiné la relation entre la perception de la vitesse et l'habilité à contrôler la vitesse de marche. Douze jeunes adultes (23.0 ± 2.4 ans) et douze adultes plus âgées (68.8 ± 4.4 ans) ont participé à une évaluation de la perception de la vitesse et à deux évaluations de la démarche. Lors de l'expérience de perception de la vitesse, les participants étaient en position assise et portaient un casque de réalité virtuelle illustrant leur déplacement le long d'un corridor à différentes vitesses. Ensuite, les participants devaient identifier laquelle des deux scènes présentées était la plus rapide. Les seuils de perception de la vitesse ont été mesurés par la moyenne géométrique des huit derniers changements de vitesse. Lors des tâches de marche, les participants marchaient sur un tapis roulant auto-rythmé en portant un casque de réalité virtuelle montrant des scènes présentées à des vitesses de FO variant de 0,25 à 2 fois leur vitesse de marche confortable. Lors du premier test de marche, les participants devaient marcher la longueur du corridor qui décrivaient des vitesses variées de FO (condition expérimentale) et ce, durant la même période de temps qu'un essai précédent illustrant un FO équivalant à leur vitesse confortable de marche (condition contrôle). Lors de la deuxième session, on a demandé aux participants de marcher à une vitesse équivalente à la vitesse du FO présentée dans l'environnement virtuel. La modulation de la vitesse de marche a été mesurée selon la pente entre les changements de vitesse de marche et les changements de vitesses du FO (premier test de marche) et avec les erreurs absolues de vitesse de marche par rapport à la vitesse cible (deuxième test de marche). Les adultes plus âgés ont démontré des seuils plus élevés de discrimination des vitesses, des pentes plus atténuées et de plus grandes marges d'erreurs de vitesse lorsque comparés aux jeunes adultes. Parmi le groupe plus âgé, les seuils de discrimination des vitesses n'étaient pas reliés de façon significative aux habiletés à moduler la vitesse de marche, tel que mesurés par les pentes et les erreurs de vitesse. Ces résultats indiquent que le vieillissement affecte autant l'habileté à percevoir les vitesses du FO que celle à moduler sa vitesse de marche en réponse aux changements de vitesse de FO. Ces observations suggèrent qu'une mauvaise perception de mouvements visuels pourrait être un des facteurs contribuant au déclin de la mobilité chez les personnes âgées.
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Reinikka, Ritva Sinikka. „Credibility, speculation and the speed of trade liberalization with an application to Kenya“. Thesis, University of Oxford, 1994. http://ora.ox.ac.uk/objects/uuid:8f156602-ac18-4d54-b6be-cd7b372af38b.
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This thesis studies the causes and consequences of the credibility problem in trade liberalization, with a special reference to African economies. The two necessary conditions for credibility are found to be macroeconomic compatibility and time-consistency, while the sufficient conditions are more difficult to identify. A lack of credibility is typically probabilistic as private agents may be uncertain about the government's intentions, or the future terms of trade. The first part of the thesis develops a theory of economic behaviour in the absence of credibility. Due to private responses, incredibility creates a welfare cost which may arise from (i) non optimal intertemporal substitution in consumption, (ii) accumulation of stocks of imports, (iii) insufficient relocation of factors, and (iv) deferral of investment. A simple consumption model and two production models are used to assess the magnitude of the welfare cost and to derive a cost curve as a function of the probability of default. A non-monotonic curve with kinks emerges. Many standard results concerning the speed of liberalization change drastically when the assumption of full credibility is relaxed. Containing consumption costs would typically call for a gradual reform to reduce the incentive to accumulate inventories, while, from the production point of view, a big bang or initial overshooting are preferable. Gradualism is preferable when (i) reserves may otherwise be depleted by speculative imports, forcing the government to abandon the reform, (ii) only incremental devaluation is possible, or (iii) the level of the implicit tariff is unknown. The second part examines how liberalization episodes can be identified empirically using a quantitative measure of trade policy. The average implicit tariff index, which is the ratio of the domestic deflator to the world price index, is derived for Kenya. As the domestic deflator appears to be biased, a hypothetical implicit tariff index is derived from a Linear Expenditure System. Further, the other empirical study quantifies the social cost of incredibility during four Kenyan reforms. Three hypotheses are tested: (i) speculative accumulation of imports, (ii) deferral of investment, and (iii) increased liquidity in response to perceived uncertainty about future trade policy. The highest welfare cost was incurred during the 1980 reform which was not coordinated with exchange rate management and was therefore incompatible.
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Reif, Angela. „Self Regulatory Depletion Effects On Speed Within A Complex Speech Processing Task“. Bowling Green State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1400183863.
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Vujacic, Sanja. „Régulation des relations interétatiques en position de dépendance : Étude du cas de la Croatie“. Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLV103/document.
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Dans cette thèse, nous avons cherché à mimer la gouvernance du système de régulation des relations interétatiques de l’Espace croate, dans le respect des propriétés structurelles des systèmes sociaux adaptatifs régis par les lois naturelles, en particulier les principes d’auto-organisation et de complexité. La modélisation de l’organisation des relations interétatiques dans l’Espace croate nous a permis d’étudier la complexité de la gouvernance qui est en jeu entre les parties et le tout, dans les interactions entre trois niveaux de régulation (national, régional, international). Elle nous a amenée aussi à définir les risques systémiques comme des défauts de capacité de régulation des relations interétatiques qui menacent la stabilité (la sécurité) de l’Espace croate. Nous sommes parvenue à la conclusion que la première source de risques est le projet géopolitique et géoéconomique de l’expansion de l’Alliance atlantique vers l’Est eurasiatique et l’absence de projets de politiques extérieures autonomes aux échelles nationale et européenne. La seconde source de risques est l’imbrication inter/transnationale entre les organisations, licites ou illicites : politiques, financières, économiques, juridiques, médiatiques, les services de sécurité et de renseignement selon le projet de mondialisation néolibéral dont est doté le système de régulation des relations interétatiques. L’étude du cas de la transition croate a débouché sur le constat qu’elle a été une émergence de cette imbrication, dont l’objectif principal n’était pas l’indépendance politico-économique nationale, mais une privatisation privilégiée au prix de la précarisation par la dévastation économique et démographique de l’Espace croate et de la mise en position de dépendance du jeune État croate par rapport aux intérêts de cette imbrication inter/transnationaleIn this thesis we have tried to mimic the governance of the Croatian interstate relations regulation system in compliance with the structural properties of adaptive social systems that are directed by natural laws, in particular the principles of self-organization and complexity. Modelling the organization of interstate relations in the Croatian area enabled us to study the complexity of governance expressed in the dynamic between the whole and the parts, in relation to the interactions between three regulation levels (national, regional, international). It also led us to define systemic risk as regulation capacity defect of interstate relations that threaten the stability (security) of the Croatian space. We reached the conclusion that the primary source of risk is the geopolitical and geo-economic project of the expansion of NATO to the Orient, as well as lack of autonomous foreign policies on national and European levels. The second source of risk is the inter / transnational nesting between organizations, legal or illegal: political, financial, economic, media, justice, security and intelligence services according to the neoliberal globalization project that animates the interstate relations regulation system. The case study of the Croatian transition led to the conclusion that it was an emergence of this nesting whose main objective was not national political and economic independence but a privileged privatization which price to pay is economic and demographic devastation, a precarious Croatian contemporary society and the young Croatian state’s position of dependence to the interests of inter / transnational nesting
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Goksu, Omer. „Shaft Transducerless Vector Control Of The Interior Permanent Magnet Motor With Speed And Position Estimation Using High Frequency Signal Injection And Flux Observer Methods“. Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/12609617/index.pdf.
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In this thesis, shaft transducerless vector control of Interior Permanent Magnet (IPM) motor with speed and position estimation using saliency based high frequency signal injection and fundamental model based flux observer methods will be investigated. The magnetic saliency characteristic of a 2.2-kW IPM motor will be experimentally extracted by means of high frequency signal injection. High frequency signal injection method will be used to estimate the speed and position at zero and low speed based on the magnetic saliency of the IPM motor. At high speed, fundamental model based flux observer method will be utilized for speed and position estimation. Seamless transition between the two estimation methods will be provided. Using the estimated speed and position information, the motor will be closed loop vector controlled and the drive motion performance over wide speed and load range will be investigated. The IPM motor drive and the estimation/control algorithms will be modeled and their performance will be demonstrated by detailed computer simulations. A three-phase voltage source inverter and a motor test bench will be built, and the estimation/control algorithms will be implemented on a DSP based motor control platform. The IPM motor drive system will be tested in the laboratory and the theory and simulation results will be verified by the experiments.
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Villet, Wikus Theo. „Critical evaluation and application of position sensorless control techniques for reluctance synchronous machines“. Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86527.
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Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: The position sensorless controllability of the reluctance synchronous machine (RSM) is investigated in this thesis with the focus on industry applications where variable and dynamic torque is required from startup up to rated speed. Two low speed as well as one medium to high speed position sensorless control (PSC) method for RSMs are investigated. These methods are extended to operate in the entire rated speed region with a hybrid PSC structure that makes use of phase locked-loop synchronisation and a hysteresis changeover method. It is shown in this thesis that PSC of the lateral rib rotor RSM is not possible from zero up to ± 0.2 p.u current. It is shown through finite element (FE) simulations that PSC of the ideal rotor RSM however, is possible at zero reference current. A novel construction method is used to build two ideal rotor RSMs. Measured flux linkage curve results of the ideal rotor RSMs correlate well with simulation results and it is shown that the electrical angle of the machine can be tracked successfully at zero reference current. The FE simulation package is used to compare the saliency of the RSM on a per-unit scale to three types of field intensified permanent magnet (FI-PM) synchronous machines and a field weakening interior permanent magnet synchronous machine. It is shown that the saliency of the RSM is larger than that of the investigated PM machines from zero up to rated load. It is thus concluded that the RSM is well suited to saliency-based PSC (SB-PSC) methods, which are used to control synchronous machines at startup and low speeds. The hybrid PSC methods developed in this thesis, are tested and evaluated on three proposed industry applications. The first is a reluctance synchronous wind generator with an inverter output LC filter. The LC filter allows long cables to be used and reduces the voltage stress on the stator windings of the machine. The combination of the LC filter and hybrid PSC method allows the power electronics and controller to be stationed in the base of the turbine tower. A new stator quantity estimation method is derived to omit the need of current and voltage sensors on the machine side of the LC filter. Good maximum power point tracking laboratory results are shown with the high frequency injection-assisted hybrid PSC method. The second application investigated is a position sensorless controlled variable gear electric vehicle (EV) RSM drive. Simulation and measured results show good torque capabilities of the position sensorless controlled EV RSM. It is shown through simulation results that the fundamental current harmonic is dominant in the demodulation scheme of the high frequency injection position sensorless control (HFIPSC) method due to the high current rating of the proposed RSM. The HFI-PSC method is extended to reduce the effect of the fundamental current harmonic in the demodulation scheme without adding any additional filters. The final investigated application is a novel mine scraper winch, which uses two position sensorless controlled RSMs to retrieve ore from the blast site underground. The new design improves on the safety, efficiency and durability of the current scraper winch design. Measured results show that the position sensorless controlled winch RSM is able to deliver rated startup torque with both investigated SB-PSC methods. Finally an automation method is implemented and tested to limited the applied force on the scraper and automatically free itself when stuck.
AFRIKAANSE OPSOMMING: Die posisie sensorlose beheer eienskappe van die reluktansie sinchroonmasjien (RSM) word in hierdie tesis ondersoek met die fokus op industriële toepassings waar varierende dinamiese draaimoment vereis word vanaf stilstand tot by ken spoed. Twee lae spoed- en een ho¨e spoed posisie sensorlose beheer (PSB) metodes vir RSMe is ondersoek. Hierdie metodes is uitgebrei om twee hibriede PSB metodes to skep wat die RSM van stilstand tot by kenspoed posisie sensorloos kan beheer. Die ontwikkelde hibriede metodes maak gebruik van ’n histerese oorskakelings skema en fase geslote lus sinchronisasie Daar word in hierdie tesis bevestig dat die laterale rib RSM nie beheer kan word met die geondersoekte PSB metodes by nul stroom nie. Eindige element simulasie resultate wys egter daarop dat die ideale rotor RSM wel beheer kan word met die geondersoekte metodes by nul stroom. ’n Nuwe konstruksie metode is voorgestel om twee ideale rotor RSMe to bou. Gemete vloed omsluiting kurwes resultate korreleer baie goed met dié van die eindige element simulasies. Gemete resultate wys ook daarop dat PSB van die nuwe masjiene moontlik is by nul stroom. ’n Eindige element pakket is gebruik om die speek-koëffissiënt van die RSM te vergelyk met drie tipes veld-versterkte permanent magneet masjiene, asook een veld verswakte permanent magneet versinkte masjien. Die simulasie resultate wys dat die RSM se speek-koëffissiënt hoër is as die van die geondersoekte permanent magneet masjiene. Die RSM is dus geskik vir speek-koëffissiënt georienteerde PSB metodes, wat hoofsaaklik by stilstand en lae spoed gebruik word. Die ontwikkelde hibried PSB metodes is getoets en geëvalueer met drie voorgestelde industriële toepassings. Die eerste is ’n reluktansie sinchroon wind generator met ’n omsetter uittree laagdeurlaat filter. Die laagdeurlaat filter laat toe dat langer kabels vanaf die omsetter na die generator gebruik kan word. Die kombinasie van die laagdeurlaat filter en die PSB metodes laat toe dat die drywingselektronika en die beheerders in die toring basis geplaas kan word. Dit kan die gewig van die nasel verminder. Goeie maksimum drywingspunt volging laboratorium resultate word getoon met die hoë frekwensie ondersteunde hibried PSB metode. Die tweede geondersoekte toepassing is ’n posisie sensorlose beheerde, varierende ratkas elektriese voertuig RSM. Goeie simulasie en gemete draaimoment resultate van die RSM word getoon. Simulasie resultate toon dat die fundamentele q-as stroom harmoniek dominant is in die demodulasie skema van die hoë frekwensie PSB metode, as gevolg van die hoë ken stroom van die motor. Die hoë frekwensie PSB metode is uitgebrei om die fundamentele stroom harmoniek te onderdruk in die demodulasie skema sonder om enige filters by te voeg. Die finale toepassing is ’n nuwe myn windas wat van twee posisie sensorlose beheerde RSMe gebruik maak om klippe ondergronds te verplaas vanaf die ontploffings area. Die voorgestelde ontwerp verbeter die huidige ontwerp ten opsigte van die veiligheid, energie effektiwiteit en robuustheid. Gemete resultate wys dat ken draaimoment moontlik is met altwee speek-koëffissiënt metodes. ’n Automasie metode, wat die maksimum draaimoment op die windas beperk en automaties homself bevry indien hy vasval, is voorgestel en geëvalueer.
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Bouwer, Pieter. „Modelling, design and implementation of a small-scale, position sensorless, variable speed wind energy conversion system incorporating DTC-SVM of a PMSG drive with RLC filter“. Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80242.
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Thesis (MScEng)--Stellenbosch University, 2013.Wind energy has proven to be a viable source of clean energy, and the worldwide demand is growing rapidly. Variable speed topologies, with synchronous generators and full-scale converters, are becoming more popular, and the e ective control of these systems is a current trend in wind energy research. The purpose of this study is the modelling, design, simulation and implementation of a small-scale, variable speed wind energy conversion system, incorporating the position sensorless direct torque control with space vector modulation, of a permanent magnet synchronous generator, including an RLC converter lter. Another aim is the development of a gain scheduling algorithm that facilitates the high level control of the system. Mathematical models of the combined lter-generator model, in the stationary and rotating reference frames, are presented and discussed, from which equivalent approximate transfer functions are derived for the design of the controller gains. The design of the controller gains, RLC lter components, gain scheduling concept and maximum power point tracking controller are presented. It is discovered that the RLC lter damping resistance has a signi cant e ect on the resonance frequency of the system. The system is simulated dynamically in both Simulink and the VHDL-AMS programming language. Additionally, the maximum power point tracking controller is simulated in the VHDL-AMS simulation, including a wind turbine simulator. The simulation results demonstrate good dynamic performance, as well as the variable speed operation of the system. The practical results of torque and speed controllers show satisfactory performance, and correlate well with simulated results. The detailed gain scheduling algorithm is presented and discussed. A nal test of the complete system yields satisfactory practical results, and con rms that the objectives of this thesis have been reached.
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Liu, Zhen. „Reconstruction and Control of Tip Position and Dynamic Sensing of Interaction Force for Micro-Cantilever to Enable High Speed and High Resolution Dynamic Atomic Force Microscopy“. The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1483629656167247.
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Pramono, Hadi Sasongko. „Etude et réalisation de régulateurs adaptatifs numériques de tension et de vitesse d'un groupe turbo-alternateur“. Grenoble INPG, 1988. http://www.theses.fr/1988INPG0052.
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Cette thèse décrit l'étude et la réalisation d'un régulateur numérique de groupe turbo alternateur dont les paramètres varient en fonction du point de fonctionnement de la machine. D'abord, une étude comparative d'application de la commande adaptative aux groupes de production est présentée. Les méthodes de commande adaptative comportant le schéma, la stratégie, le type et le nombre de variables sont analysées dans la suite de façon à trouver la plus convenable. Ensuite, est présentée l'étude théorique de la conception de régulateurs adaptatifs modal et optimal. Les performances des régulateurs proposés sont décrites par simulation numérique et par l'implantation sur un modèle dynamique du réseau construit autour d'un micro alternateur et commandé par un microprocesseur. Enfin, la conclusion comporte l'analyse des résultats obtenus avec les avantages et les inconvénients ainsi que les propositions pour la poursuite de cette étude
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Bramley, Wesley Joel. „The relationship between strength, power and speed measures and playing ability in premier level competition rugby forwards“. Queensland University of Technology, 2006. http://eprints.qut.edu.au/16252/.
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Physical tasks such as scrummaging, rucking and mauling are highly specific to rugby and also place unique physiological demands on the different playing positions within the forwards. Traditionally, the recruitment and development of talented rugby union players has focused on the assessment of motor skills and game intelligence aspects of performance, with less emphasis placed on the specific physiological requirements of playing positions in rugby. The purpose of this investigation was to measure the position-specific strength, speed and power characteristics of Premier rugby forwards in order (1) to determine whether any differences existed in the physiological characteristics of the different forward playing positions (prop, lock and loose forwards) and (2) to investigate the relationship between these physiological characteristics and coaches evaluations of football playing ability. Twenty-two male Premier level competition rugby forwards, consisting of eight prop forwards, five lock forwards and nine loose-forwards participated in the study. The Grunt 3000, a rugby specific force testing device was utilised to measure the static and dynamic horizontal strength during simulated scrummaging and rucking/mauling movements. Sprint times relating to acceleration ability (0 -10m, 0-20m) and maximum running speed (20 - 40m) were measured during a 40m sprint running test. In addition, force, power and displacement characteristics of a countermovement vertical jump were calculated from trials performed on a force plate. Also, player performance skill and physical capacity scores were determined independently by experienced coaches who assessed them based on their performances during the season. One-way analysis of variance and effect size statistics evaluated differences in the measured variables between forward playing positions and linear regression analysis evaluated the relationship between the coaches' scores of player performance skill and physical capacity and game specific measures of strength speed and power. Since there were no statistical significant differences between forward groups for horizontal force and countermovement jump variables and these analyses lacked statistical power, an effect size statistic was used to establish trends for differences in force and CMJ variables between the groups. There were moderate effect size differences between groups for horizontal impact force with prop and lock forwards producing 17.7% and 12.8% more force than the loose forwards respectively. No clear differences were apparent between forward positional groups for mean dynamic horizontal force and countermovement jump displacement of the centre of gravity. A significant difference (p =0.049) was shown between forward positional groups over the 0-40m sprint distance. Also, moderate effect size differences between pairs of groups were evident in 0-10m, 0-20m, 20-40m sprint times with both loose forwards and lock forwards on average, 6% faster than the prop forwards. A backward linear regression analysis revealed that the single best predictor of coaches' physical capacity and performance skill scores was the 20 - 40m sprint performance, accounting for 28% of the variance in player's physical capacity scores and 29% of the variance in player's performance skill scores. Whole-body horizontal static strength and impact strength in prop forwards and dynamic horizontal strength (relative to body mass) and sprint acceleration ability in loose forwards represent key factors for consideration when selecting forward players to these positions in the Premier rugby competition. The vertical jumping ability of all forward positional groups needs to be confirmed in a future study utilising a line-out specific countermovement jump test (free use of arm swing and line-out lifters in the jump) on a force plate. Monitoring of performance in rugby forwards should include an acceleration sprint test (0-10m) as this is specific to the sprinting patterns of forward players during a game, and maximum sprinting speed test (20-40m) as this test has the ability to discriminate between skilled and less-skilled rugby union forwards.
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Venegas-Ortiz, Juan. „Statistical mechanics of gene competition“. Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/9372.
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Statistical mechanics has been applied to a wide range of systems in physics, biology, medicine and even anthropology. This theory has been recently used to model the complex biochemical processes of gene expression and regulation. In particular, genetic networks offer a large number of interesting phenomena, such as multistability and oscillatory behaviour, that can be modelled with statistical mechanics tools. In the first part of this thesis we introduce gene regulation, genetic switches, and the colonization of a spatially structured media. We also introduce statistical mechanics and some of its useful tools, such as the master equation and mean- field theories. We present simple examples that are both pedagogical and also set the basis for the study of more complicated scenarios. In the second part we consider the exclusive genetic switch, a fundamental example of genetic networks. In this system, two proteins compete to regulate each other's dynamics. We characterize the switch by solving the stationary state in different limits of the protein binding and unbinding rates. We perform a study of the bistability of the system by examining its probability distribution, and by applying information theory techniques. We then present several versions of a mean field theory that offers further information about the switch. Finally, we compute the stationary probability distribution with an exact perturbative approach in the unbinding parameter, obtaining a valid result for a wide range of parameters values. The techniques used for this calculation are successfully applied to other switches. The topic studied in the third part of the thesis is the propagation of a trait inside an expanding population. This trait may represent resistance to an antibiotic or being infected with a certain virus. Although our model accounts for different examples in the genetic context, it is also very useful for the general study of a trait propagating in a population. We compute the speed of expansion and the stationary population densities for the invasion of an established and an expanding population, finding non-trivial criteria for speed selection and interesting speed transitions. The obtained formulae for the different wave speeds show excellent agreement with the results provided by simulations. Moreover, we are able to obtain the value of the speeds through a detailed analysis of the populations, and establish the requirements for our equations to present speed transitions. We finally apply our model to the propagation in a position-dependent fitness landscape. In this situation, the growth rate or the maximum concentration depends on the position. The amplitudes and speeds of the waves are again successfully predicted in every case.
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Saliba, Pamela. „High-frequency trading : statistical analysis, modelling and regulation“. Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLX044.
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Cette thèse est constituée de deux parties liées l’une à l’autre. Dans la première, nous étudions empiriquement le comportement des traders haute fréquence sur les marchés financiers européens. Nous utilisons les résultats obtenus afin de construire dans la seconde partie de nouveaux modèles multi-agents. L’objectif principal de ces modèles est de fournir aux régulateurs et plateformes de négociation des outils innovants leur permettant de mettre en place des règles pertinentes pour la microstructure et de quantifier l’impact des divers participants sur la qualité du marché.Dans la première partie, nous effectuons deux études empiriques sur des données uniques fournies par le régulateur français. Nous avons accès à l’ensemble des ordres et transactions des actifs du CAC 40, à l’échelle de la microseconde, avec par ailleurs les identités des acteurs impliqués. Nous commençons par comparer le comportement des traders haute fréquence à celui des autres intervenants, notamment pendant les périodes de stress, en termes de provision de liquidité et d’activité de négociation. Nous approfondissons ensuite notre analyse en nous focalisant sur les ordres consommant la liquidité. Nous étudions leur impact sur le processus de formation des prix et leur contenu informationnel selon les différentes catégories de flux : traders haute fréquence, participants agissant pour compte client et participants agissant pour compte propre.Dans la seconde partie, nous proposons trois modèles multi-agents. À l’aide d’une approche à la Glosten-Milgrom, nous parvenons avec notre premier modèle à construire l’ensemble du carnet d’ordres (spread et volume disponible à chaque prix) à partir des interactions entre trois types d’agents : un agent informé, un agent non informé et des teneurs de marché. Ce modèle nous permet par ailleurs de développer une méthodologie de prédiction du spread en cas de modification du pas de cotation et de quantifier la valeur de la priorité dans la file d’attente. Afin de se concentrer sur une échelle individuelle, nous proposons une deuxième approche où les dynamiques spécifiques des agents sont modélisées par des processus de type Hawkes non linéaires et dépendants de l’état du carnet d’ordres. Dans ce cadre, nous sommes en mesure de calculer en fonction des flux individuels plusieurs indicateurs pertinents relatifs à la microstructure. Il est notamment possible de classer les teneurs de marché selon leur contribution propre à la volatilité. Enfin, nous introduisons un modèle où les fournisseurs de liquidité optimisent leurs meilleurs prix à l’achat et à la vente en fonction du profit qu’ils peuvent générer et du risque d’inventaire auquel ils sont confrontés. Nous mettons alors en évidence théoriquement et empiriquement une nouvelle relation importante entre inventaire et volatilitéThis thesis is made of two related parts. In the first one, we study the empirical behaviour of high-frequency traders on European financial markets. We use the obtained results to build in the second part new agent-based models for market dynamics. The main purpose of these models is to provide innovative tools for regulators and exchanges allowing them to design suitable rules at the microstructure level and to assess the impact of the various participants on market quality.In the first part, we conduct two empirical studies on unique data sets provided by the French regulator. It covers the trades and orders of the CAC 40 securities, with microseconds accuracy and labelled by the market participants identities. We begin by investigating the behaviour of high-frequency traders compared to the rest of the market, notably during periods of stress, in terms of liquidity provision and trading activity. We work both at the day-to-day scale and at the intra-day level. We then deepen our analysis by focusing on liquidity consuming orders. We give some evidence concerning their impact on the price formation process and their information content according to the different order flow categories: high-frequency traders, agency participants and proprietary participants.In the second part, we propose three different agent-based models. Using a Glosten-Milgrom type approach, the first model enables us to deduce the whole limit order book (bid-ask spread and volume available at each price) from the interactions between three kinds of agents: an informed trader, a noise trader and several market makers. It also allows us to build a spread forecasting methodology in case of a tick size change and to quantify the queue priority value. To work at the individual agent level, we propose a second approach where market participants specific dynamics are modelled by non-linear and state dependent Hawkes type processes. In this setting, we are able to compute several relevant microstructural indicators in terms of the individual flows. It is notably possible to rank market makers according to their own contribution to volatility. Finally, we introduce a model where market makers optimise their best bid and ask according to the profit they can generate from them and the inventory risk they face. We then establish theoretically and empirically a new important relationship between inventory and volatility
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Brambilla, Elisa. „Investigation of E. coli genome complexity by means of fluorescent reporters of gene expression“. Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066607/document.
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Escherichia coli est capable de survivre dans de nombreux environnements différents. Les informations nécessaires à cette adaptation sont codées dans le chromosome. Cette molécule circulaire est condensé dans une structure compacte protéines-ADN, appelée nucléoïde. Le chromosome n¿est pas uniforme et montre notamment une distribution inégale de sites de fixation de protéines et de séquences riches en AT. Il a été montré que la position des gènes importants pour la cellule est hautement conservée dans les gamma-protéobactéries. Ces différences le long du chromosome et cette conservation de la position suggèrent que la position du gène peut influencer son expression. Pour tester cette hypothèse, on a étudié l'expression d'un gène fluorescent inséré dans différentes positions autour du chromosome. L'expression de ce gène est contrôlé par des promoteurs différemment régulés: un est réprimé par la protéine H-NS, un est non régulé et un est sensible au superenroulement de l'ADN. Nous avons étudié l'expression dynamique de ces promoteurs pendant les différentes phases de croissance dans différentes conditions. Nous avons montré que l'expression du promoteur dépendant de la protéine H-NS est liée à l'emplacement sur le chromosome. En effet, la répression par H-NS est accrue en présence de séquences riches en AT. Nous avons également étudié l'influence d'un gène divergent sur l'expression de gènes rapporteurs en fonction de la position chromosomique. Nous avons montré que cette influence dépend de la localisation du gène. Nous avons donc demontré l'impact de la position chromosomique sur l'expression des gènes tout en donnant une nouvelle perspective sur la complexité du génomeEscherichia coli is able to survive in many different environments. The information necessary for this adaptation is encoded in the chromosome. This circular molecule is condensed in a compact DNA-protein structure, called the nucleoid. The chromosome is not uniform, and shows uneven distributions of nucleoid-associated proteins (NAPs) binding sites, AT-rich sequences and general protein occupancy domains. It has been demonstrated that the position of important genes is highly conserved in ?-Proteobacteria. These differences along the chromosome and the conserved position of important genes suggest that the position of the gene can influence gene expression. To test this hypothesis, I studied the expression of a fluorescent reporter gene inserted in different positions around the chromosome. The expression of the reporter is driven by differently regulated promoters, one repressed by the important NAP H-NS, one non regulated and one subject to supercoiling and stringent control. We studied the dynamical expression of these promoters in different growth conditions, growth phases, upon nutritional upshift and under stress. We showed that the expression of the H-NS dependent promoter depends on the location on the chromosome, because H-NS repression is enhanced in presence of AT-rich sequences. We also studied the influence of a divergent gene on the reporter expression as a function of chromosomal position, and showed that this influence depends on the location of the gene. With our study we have been therefore able to show the impact of chromosomal position on gene expression and to give a new perspective on genome complexity
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Andersson, Oskar. „Inclusion of Wind Turbines into Frequency Support Services : Exploring frequency stability issues and comparing regulation power market products“. Thesis, Uppsala universitet, Institutionen för elektroteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-435076.
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There is a trend in Sweden towards increasing the electricity production from renewable energy sources in the electric grid. The increased share of renewables could be seen as essential for Sweden to be able to meet the obligated climate goals. Integration of renewables will enable Sweden to be a progressive part in reducing greenhouse gases and decreasing the global warming. However, one issue with renewable energy sources is the inverter governed production. This, together with the decommission of larger synchronous generators, results in decreasing the inertia and increasing the instability inthe grid. This thesis is dedicated to elaborating on frequency stability issues and investigating how Variable Speed Wind Turbines (VSWT) could contribute towards stabilized operation when included in frequency support services. The study is generated through an extensive research process where focus areas are identified. Questions are purposed and then discussed through interviews with experienced people in the field. Estimated power production series from a wind turbine park (WTP) are applied in a constructed model to study the possibilities appearing when including VSWTs in frequency support services. The income generated from including VSWTs in different regulation power market services is with the model compared against solely procuring the production capacity on the day ahead market. The studied frequency support services are then compared altogether to generate favorable solutions. The study examines both economic as well as technical features of the inclusion of VSWTs in frequency support services. Results found in the study were that inclusion of wind turbines for power regulation purposes could be seen as increasingly manageable and needed in the electric grid. The maturity of technical solutions alongwith a transition in the regulation power market could be observed as leading factors. The diversification of regulation abilities and the increasing economic incentives in the regulation power market was also found to be important reasons for including wind turbines in the regulation power market. In the study, it was also found thataggregating the power production from several VSWT could increase the ability to deliver the studied services. It was concluded that inclusion of VSWT in the frequency containment reserve during disturbed operation for down-regulation purposes as well as the fast frequency reserve was the most promising frequency support products for the inclusion of wind turbines. When including battery energy storages and to a larger part managing the durability demands for the services then the frequency contain reserve for normal operation and the frequency containment reserve for disturbed operation for upregulation purposes could be observed as preferable alternatives. Regulation abilities were concluded as achievable with the use of pitch and torque regulation techniques available in the variable speed wind turbine.
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Xu, Li-Qing, und 許立慶. „Position regulation and speed control of a rotating beam via variable structure control“. Thesis, 1998. http://ndltd.ncl.edu.tw/handle/51689175475671076130.
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碩士中原大學
機械工程研究所
86
This paper presents the vibration control of the flexible rotating beam with a tip mass. Modeling and control of a flexible rotating beam has received a great deal of attention. When a tip mass of a flexible beam is a rigid body, not only bending vibration but also torsional vibration will occur. In this paper, the bending and torsion vibrations and rigid-body motion are governed by the nonlinear coupled partial differential equations associated with a set of nonlinear boundary conditions. The coupling provides the opportunity to suppress the flexible vibration by control torque applying to the rotating beam. A new variable structure control (VSC) law designed by Lyapunov''s direct method is proposed for vibration suppression and tracking control simultaneously. Asymptotic stability of the controlled system is proved. Simulation results are provided to show the effectiveness of the controller design.The rigid body motion and flexible vibration system can be controlled because of their coupling terms in governing equations. Due to the applying of new variable structure control method, the derived algorithm ensures that system satisfies the reaching conditions and stability conditions. By selecting a suitable sliding mode function, new variable structure control can design a controller for the propose of position regulation and speed control and sliding mode exist. The new VSC controller prevents the chattering and the control force prevents closing infinite. Although the design procedure of VSC is simple, numerical results have shown that the proposed VSC not only very effective eliminates the vibration of the flexible vibration of the rotating beam, but also keeps good tracking performance. In speed control, the sliding mode design is different from position control. The speed error is closed to zero that means rotating speed is closed to our target speed. Using the PDA controller law, no information of the flexible deformations is needed and the system is globally stable. The PDA controller is simulation results reveal that this controller is effective for regulation and vibration control.The design procedure of vibration control can also be applied to any other rigid body motion and flexible vibration coupled system.
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Wen-HongLi und 李文宏. „Design and Implementation of a Position Sensorless IPMSM Drive with Characteristics of Wide Range of Speed Regulation and Reliable Start-up“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/zq9x5u.
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碩士國立成功大學
電機工程學系
103
This thesis aims at developing a permanent magnet synchronous motor (PMSM) drive for starting up a PMSM motor without using any position sensor. The technology developed in this thesis is composed of three different methods: the first one is the high-frequency pulse voltage signal estimation method; the second one is the high-frequency voltage signal injection method for the low-speed zone; and the last one is the sliding mode current control method, which is implemented by using a sliding mode current observer, for the medium-speed zone and the high-speed zone. The high-frequency voltage signal injection method uses the saliency of an interior PSMS to estimate the rotor position. In contrast, the sliding mode current observer uses the back electromotive force (EMF) to estimate the rotor position. However, when the PMSM is stationary or rotates in low speed, the sliding mode observer based approach cannot estimate the rotor position because the value of back EMF is too small. As a result, the rotor position of the PMSM needs to be aligned and open loop startup needs to be carried out. After the PMSM reaches to the threshold speed, the sliding mode current observer is then switched on to estimate the rotor position. In order to cope with the aforementioned problem, in this thesis the relationship between the rotor position and the size of the inductor that can be known from the principle of magnetic saturation of the stator core is exploited to estimate the rotor position of the motor when stationary, and to avoid a temporary inversion phenomenon caused by aligning the rotor position. After the initial rotor position is detected, the high-frequency voltage signal injection method is used for starting up a PMSM. Compared to the commonly used variable voltage variable frequency (VVVF) open loop startup method, the proposed method is more robust and has better ability in noise suppression, in which it can further expand the range of speed control. The thesis uses a low-cost 16 bits single-chip microcontroller dsPIC33FJ32MC304 to realize the position sensorless field oriented control drive for interior PMSMs. Several experiments have been conducted to verify the feasibility of the proposed architecture.