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1
Örjegård, Johan. "Wireless control of wall switches : A module that controls your existing wall switch with an application." Thesis, Högskolan i Halmstad, Akademin för informationsteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-33102.
Full textAbstract:
In this project a home-automation-solution is developed that wirelessly can control an existing wall switch with an application from a smart device. The purpose of the project is to develop a new solution that doesn’t require any electrical knowledge to mount the solution. Exiting solutions for controlling a switch require a module that is connected in series with the switch. The project will develop a module that can be mounted next to the selected wall switches to control them without electrical connection to the AC-voltage of the switch. Instead there is a servo that physically press the switch that is controlled. The servo motor is controlled wirelessly via Bluetooth Low Energy using an Android application, thus, a force is applied to the switch to turn on or off. A rechargeable lithium battery of 3.7 volts powers the whole module. Therefore, a "power-board" was developed that step up the voltage to 5 V. There are also components on the board that manage battery charging via microUSB. The Android application communicates via a Bluetooth Low Energy module that is mounted on a CPU board and has been developed and specifically manufactured to fit into the project. Both the power-board and processor-board is developed from own drawings and PCB layouts, and made with a manual etching method. The chassis has also been designed and manufactured with a 3D printer. The chassis holds all circuit boards, battery and a mount for the servo. The result is a working prototype that can be mounted on a switch and then operate the switch within the range of BLE. The prototype has a run time of each charging cycle of about 60 days under conditions that it is operated, on average, three times per day.I detta projekt utvecklas en hemautomationslösning som kan styra befintliga väggströmbrytare trådlöst via en applikation från en smart enhet. Syftet med projektet är att utveckla en ny lösning där det inte krävs någon elinstallationskunskap för att montera lösningen. Dagens lösningar för att trådlöst styra en strömbrytare kräver att en modul kopplas in i serie med strömbrytaren. I projektet utvecklas en modul som kan monteras bredvid utvalda strömbrytare för styrning av dem utan att behöva ansluta sig galvaniskt till brytarens starkström. I stället sitter en servomotor i modulen som fysiskt trycker på den strömbrytare som skall styras. Servomotorn kan styras trådlöst via Bluetooth Low Energy med hjälp av en androidapplikation, på så sätt appliceras en kraft på brytarvippan och slå på eller av den. Hela modulen är strömförsörjd av ett laddningsbart litiumbatteri på 3,7 volt. Därför har ett spänningskort utvecklats som växlar upp spänningen till 5 V. På spänningskortet finns även komponenter som hanterar laddning av batteriet via microUSB. Applikationen kommunicerar via en BLE-modul som i sin tur sitter monterad på ett processorkort som har utvecklats och tillverkas speciellt för att passa in i detta projekt. Både spänningskortet och processorkortet är utvecklade ifrån egna ritningar och PCB-layouter samt tillverkade med en manuell etsningsmetod. Ett chassi har också konstruerats och tillverkats med en 3D-skrivare. Chassit rymmer alla kretskorten, batteriet och har ett motorfäste för montering av servomotorn. Resultat har blivit en fungerande prototyp som kan monteras på en strömbrytare och därefter manövrera brytaren inom den räckvidd som BLE klarar av. Prototypen har en drifttid på cirka 60 dagar under förutsättningar att den manövreras i genomsnitt vid tre tillfällen per dygn.
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Yan, Yingyi. "Unified Three-terminal Switch Model for Current Mode Controls." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/35647.
Full textAbstract:
Current-mode control architectures with different implementation approaches have been an indispensable technique in many applications, such as voltage regulator, power factor correction, battery charger and LED driver. Since the inductor current ramp, one of state variables influenced by the input voltage and the output voltage, is used in the modulator in current-mode control without any low pass filter, high order harmonics play important role in the feedback control. This is the reason for the difficulty in obtaining the small-signal model for current-mode control in the frequency domain. A continuous time domain model was recently proposed as a successful model for current-mode control architectures with different implementation. However, the model was derived by describing function method, which is very arithmatically complicated, not to mention time consuming. Although an equivalent circuit for a current mode control Buck converter was proposed to help designers to use the model without involving complicated math, the equivalent circuit is not a complete model. Moreover, no equivalent circuit for other topologies is available for designers. In this thesis, the primary objective is to develop a unified three-terminal switch model for current-mode control with different implementation methods, which are applicable in all the current mode control power converters.
First, the existing model for current mode control is reviewed. The limitation of average models and the discrete time model for current-mode control is identified. The continuous time model and its equivalent circuit of Buck converter is introduced. The deficiency of the equivalent circuit is discussed.
After that, a unified three-terminal switch model for current mode control is presented. Based on the observation, the PWM switch and the closed current loop is taken as an invariant sub-circuit which is common to different DC/DC converter topologies. A basic small signal relationship between terminal currents is studied and the result shows that the PWM switch with current feedback preserves the property of the PWM switch in power stage. A three-terminal equivalent circuit is developed to represent the small signal behavior of this common sub-circuit. The proposed model is a unified model, which is applicable in both constant frequency modulation and variable frequency modulation. The physical meaning of the three-terminal equivalent circuit model is discussed. The model is verified by SIMPLIS simulation in commonly used converters for both constant frequency modulation and variable frequency modulation.
Then, based on the proposed unified model, a comparison between different current mode control implementations is presented. In different applications, different implementations have their unique benefit on extending control bandwidth. The properties of audio susceptibility and output impedance are discussed. It is found that, for adaptive voltage positioning design, constant on-time current mode control can simplifies the outer loop design.
Next, since multiphase interleaving structure is widely used in PFC, voltage regulator and other high current applications, the model is extended to multiphase current mode control. Some design concerns are discussed based on the model.
As a conclusion, a unified three-terminal switch model for current mode controls is investigated. The proposed model is quite general and not limited by implementation methods and topologies. All the modeling results are verified through simulation and experiments.Master of Science
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Hudson, Christopher Allen. "Single-Phase, Single-Switch, Sensorless Switched Reluctance Motor Drive Utilizing a Minimal Artificial Neural Net." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/34735.
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Artificial Neural Networks (ANNs) have proved to be useful in approximating non-
linear systems in many applications including motion control. ANNs advocated in
switched reluctance motor (SRM) control typically have a large number of neurons
and several layers which impedes their real time implementation in embedded sys-
tems. Real time estimation at high speeds using these ANNs is diffcult due to the
high number of operations required to process the ANN controller. An insuffcient
availability of time between two sampling intervals limits the available computation
time for both processing the neural net and the other functions required for the motor
drive. One ideal application of ANNs in SRM control is rotor position estimation. Due
to reliability issues, elimination of the rotor position sensors is absolutely required for
high volume, high speed and low cost applications of SRM's. ANNs provide a means
by which drive designers can implement position sensorless drive technology that is
both robust and easily implemented.
It is demonstrated that a new and novel ANN configuration can be implemented
for accurate rotor position estimation in a sensorless SRM drive. Consisting of just
4 neurons, the neural estimator is the smallest of its kind for SRM rotor position
estimation. The breakthrough that provided the reduction was the addition of a non-
linear input. Typical input spaces for SRM position neural estimators consist of both
current,and fux-linkage. The neural network was trained on-line using these
inputs and a third, non-linear input provided by a preprocessed product of the two
typical inputs.Master of Science
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Zheng, Hong. "Identification of a Transcription Factor that Controls the Angiogenic Switch." Université Louis Pasteur (Strasbourg) (1971-2008), 2002. http://www.theses.fr/2002STR13196.
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Chez les mammifères adultes, l'angiogenèse se limite à des situations pathologiques telles que les tumeurs ou la cicatrisation, ainsi qu'à des processus naturels tel que le cycle menstruel. Pendant l'angiogenèse, des facteurs de croissance, secrétés par les cellules normales ou tumorales environnantes, ciblent les cellules endothéliales et rétablissent les capacités de prolifération et de différenciation des cellules endothéliales quiescentes. Une question importante est l'élucidation des circuits intra-cellulaires réglant cette " conversion angiogénique " dans les "cellules environnantes" qui déclenchent les processus pathologiques et physiologiques. Les réponses cellulaires aux facteurs de croissance sont contrôlées par les cascades MAP kinases, qui transduisent les signaux extracellulaires des récepteurs de surface activés par le ligand vers le noyau. Les MAP kinases phosphorylent des effecteurs nucléaires, tels que les Facteurs de Complexe Ternaire (TCF), une sous-famille des facteurs ets impliqués dans la prolifération cellulaire, la différenciation et la transformation,. Net se distingue des autres TCF par son activité de puissant répresseur transcriptionnel dans des conditions basales dans lesquelles les MAP kinases ne sont pas activées. Après activation par la voie Ras/ERK, NET est converti en un régulateur positif de la transcription. Net est exprimé aux stades E7. 5-8. 5 dans le réseau vasculaire en cours de développement, plus particulièrement dans les îlots sanguins du corps jaune, les vaisseaux allantoi͏̈ques, l'endocarde et l'aorte dorsale. Cette expression associée aux structures vasculaires persiste durant toute la vie de l'animal. Afin d'étudier les fonctions de Net in vivo, nous avons généré des souris comportant une mutation ciblée du gène Net. Nous avons : (a) étudié l'angiogenèse induite par la cicatrisation ; (b) examiné différents organes dans lesquels l'angiogenèse se produit naturellement chez l'adulte (utérus et ovaires) ; (c) utilisé des modèles expérimentaux in vitro, ex vivo et in vivo d'angiogenèse et de transformation, et (d) examiné différents types de tumeurs humaines. Notre étude démontre que Net se comporte comme une régulateur "commutateur" de l'angiogenèse, permettant le maintient de l'état quiescent des cellules endothéliales dans des conditions où Net n'est pas activé par les MAP kinases, et agissant comme activateur après phosphorylation par les cascades MAP kinase déclenchées in vivo par les molécules pro-angiogéniquesIn adult mammals, angiogenesis is restricted to pathological situations such as tumours and wound healing, and some natural processes such as the female reproductive cycle. During angiogenesis, growth factors, generated by surrounding normal or tumour cells, target on endothelial cells and induce quiescent endothelial cells to proliferate and differentiate. An important unresolved question is which intra-cellular circuits regulate this "angiogenic switch" in the "surrounding cells" those trigger the beginning of the pathological and physiological processes. Cellular responses to growth factors are controlled by MAP kinase cascades, that transduce extracellular signals from ligand-activated cell surface receptors to the nucleus. MAP kinases phosphorylate nuclear effectors, such as the ternary complex factors (TCFs), a sub-family of the ets transcription factors that regulate cellular proliferation, differentiation and transformation. Net differs from the other TCFs in that in basal conditions, in which MAP kinases are not activated, it strongly inhibits transcription. Upon Ras/ERK activation, NET is converted to a positive regulator to activate transcription. Net is expressed at E7. 5-8. 5 in developing vascular primodia, including the yolk sac blood islands, allantoic vessels, heart endocardium and dorsal aortae, and vascular-associated expression persists throughout whole life. In order to study the function of Net in vivo, we generated mice with a targeted disruption of the net gene. We: (a) studied wound healing induced angiogenesis; (b) examined different organs in which angiogenesis occurs naturally in the adult (uterus and ovary); (c) used in vitro, ex vivo and in vivo experimental models of angiogenesis and transformation, and (d) examined different types of human tumours. Our studies provide strong evidence that Net behaves as a switch regulator of angiogenesis, which helps to maintain the quiescent state under conditions in which Net is not activated by MAP kinases, and which acts as an activator following induction through phosphorylation by MAP kinase signalling cascades activated by pro-angiogenic molecules in vivo
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Khav, Eddie. "Visualizing an RB-E2F Cellular Switch that Controls Cell Proliferation." Thesis, The University of Arizona, 2013. http://hdl.handle.net/10150/297627.
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Mammalian cell proliferation is regulated by an Rb-E2F gene network. The input node of this network, Cyclin D, receives graded growth signals; the output node, E2F, generates an all-or-none response. That is, the Rb-E2F gene network functions as a cellular switch, converting analog growth signals into digital E2F activities. The On or Off of this Rb-E2F switch determines the On or Off of cell proliferation. To help better understand the analog/digital conversion mechanism, we constructed a reporter cell line to visualize the dynamic expression of Cyclin D and E2F genes by red and green fluorescence in individual cells, respectively.
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Sargolzaei, Arman. "Time-Delay Switch Attack on Networked Control Systems, Effects and Countermeasures." FIU Digital Commons, 2015. http://digitalcommons.fiu.edu/etd/2175.
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In recent years, the security of networked control systems (NCSs) has been an important challenge for many researchers. Although the security schemes for networked control systems have advanced in the past several years, there have been many acknowledged cyber attacks. As a result, this dissertation proposes the use of a novel time-delay switch (TDS) attack by introducing time delays into the dynamics of NCSs. Such an attack has devastating effects on NCSs if prevention techniques and countermeasures are not considered in the design of these systems. To overcome the stability issue caused by TDS attacks, this dissertation proposes a new detector to track TDS attacks in real time. This method relies on an estimator that will estimate and track time delays introduced by a hacker. Once a detector obtains the maximum tolerable time delay of a plant’s optimal controller (for which the plant remains secure and stable), it issues an alarm signal and directs the system to its alarm state. In the alarm state, the plant operates under the control of an emergency controller that can be local or networked to the plant and remains in this stable mode until the networked control system state is restored.
In another effort, this dissertation evaluates different control methods to find out which one is more stable when under a TDS attack than others. Also, a novel, simple and effective controller is proposed to thwart TDS attacks on the sensing loop (SL). The modified controller controls the system under a TDS attack. Also, the time-delay estimator will track time delays introduced by a hacker using a modified model reference-based control with an indirect supervisor and a modified least mean square (LMS) minimization technique.
Furthermore, here, the demonstration proves that the cryptographic solutions are ineffective in the recovery from TDS attacks. A cryptography-free TDS recovery (CF-TDSR) communication protocol enhancement is introduced to leverage the adaptive channel redundancy techniques, along with a novel state estimator to detect and assist in the recovery of the destabilizing effects of TDS attacks. The conclusion shows how the CF-TDSR ensures the control stability of linear time invariant systems.
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Yan, Yingyi. "Equivalent Circuit Model for Current Mode Controls and Its Extensions." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/50485.
Full textAbstract:
Current-mode control architectures have been an indispensable technique in many applications, such as Voltage Regulator, Point-of-load converters, power factor correction, battery charger and LED driver. Since the inductor current ramp is used in the modulator in current-mode control without any low pass filter, high order harmonics play important role in the feedback control. This is the reason for the difficulty in obtaining the small-signal model for current-mode control in the frequency domain. A continuous time domain model was recently proposed as a successful model for current-mode control architectures. However, the model was derived by describing function method, which is very arithmatically complicated, not to mention time consuming.For the analysis and design of non-linear system, equivalent circuit model, which is user friendly and intuitive, is an effective tool. In this dissertation, the primary objective is to develop a unified three-terminal switch model for current-mode controls using the results of describing function derivation, which characterizes the small signal property of the common subcircuit of current mode controlled PWM converters. Its application is extended to average current mode control, V2 control and other proposed novel current mode control schemes.
First, the existing model for current mode control is reviewed. The limitations of exsiting model for current-mode control are identified. Based on the universal small signal relationship between terminal currents and the results of describing function derivation, a unified three-terminal switch model for current mode control is proposed. A three-terminal equivalent circuit is developed to represent the small signal behavior of this common sub-circuit. The proposed model is applicable in both constant frequency and variable frequency modulation.
After that, the modeling of digital predictive current mode control is presented. Predictive current mode control is one of the promising digital current mode control method featuring fast dynamic response and low sample rate requirement. Many implementations were presented in past ten years. To understand the benefit and the limitation of each implementation, help the engineer to choose the modulation scheme and design the control loop, a small signal Laplace-domain model for digital predictive current mode controls is proposed. The model is extended to the multi-sampled implementation. The modeling result is summarize as the small signal equivalent circuit mode, whose form is consistant with that of analog current mode controls. Based on S-domain model, digital predictive current mode controls are compared with analog implementation to demonstrate the advantages and limitation. Implementation selection guideline and compensation is discussed based on the modeling results.
Then, using the proposed unified model is used in the analysis of average current mode control. Under proper design, the inductor current ripple passes through the current compensator and appears in PWM comparator. It significantly influence the high frequency small signal property of the converter. In chapter 3, the proportional feedback is separated from integral feedback so that the sideband frequency feedback effect can be taken into consideration. It extends the results obtained in peak-current model control to average current mode control. The proposed small signal model is accurate up to half switching frequency, predicting the sub-harmonic instability. Based on the proposed model, a new feedback design guideline is proposed. By designing the external ramp following the proposed design guideline, quality factor of the double poles at half of switching frequency in control-to-output transfer function can be precisely controlled. This helps the feedback design to achieve widest control bandwidth and proper damping.
V2 control is a popular control scheme in Point-of-load converters due to the unique fast transient response. As the output voltage ripple is used as PWM modulation ramp, V2 control has close relationship with current mode control but this relationship was not addressed in the exsiting model. Chapter 4 utilizes the three-terminal switch model to build the equivalent circuit model for V2 control, which clearly shows that V2 control is a particular implementation of current mode control, with proportional capacitor voltage feedback and load current feedback embeded.
The analysis presented in Chapter 3 provides a clear physical understanding of average current mode control. With constant frequency modulation, the control bandwidth is usually limited by the double pole at half of swithcing frequency, especially in the converters with wide duty cycle range. Chapter 5 proposed a novel I2 current mode control to improve the dynamic performance of average current mode control. In particular, constant on-time I2 control eliminates the need of external ramp while the current loop is inherently stable. Moreover, constant on-time modulation improves the light load efficiency.
As a conclusion, this dissertation proposed a unified three-terminal switch model for current mode controls. The application of this equivalent circuit model is extended to average current mode control, V2 control and the novel I2 current mode control. The Laplace-domain model of predictive current mode control is also presented. All the modeling results are verified through simulation and experiments.
Ph. D.
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Sutherland, Caleb, Yunxi Cui, Hanbin Mao, and Laurence H. Hurley. "A Mechanosensor Mechanism Controls the G-Quadruplex/i-Motif Molecular Switch in the MYC Promoter NHE III 1." AMER CHEMICAL SOC, 2016. http://hdl.handle.net/10150/621939.
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MYC is overexpressed in many different cancer types and is an intensively studied oncogene because of its contributions to tumorigenesis. The regulation of MYC is complex, and the NHE III1 and FUSE elements rely upon noncanonical DNA structures and transcriptionally induced negative superhelicity. In the NHE III1 only the G-quadruplex has been extensively studied, whereas the role of the i-motif, formed on the opposite C-rich strand, is much less understood. We demonstrate here that the i-motif is formed within the 4CT element and is recognized by hnRNP K, which leads to a low level of transcription activation. For maximal hnRNP K transcription activation, two additional cytosine runs, located seven bases downstream of the i-motif-forming region, are also required. To access these additional runs of cytosine, increased negative superhelicity is necessary, which leads to a thermodynamically stable complex between hnRNP K and the unfolded i-motif. We also demonstrate mutual exclusivity between the MYC G-quadruplex and i-motif, providing a rationale for a molecular switch mechanism driven by SP1-induced negative superhelicity, where relative hnRNP K and nucleolin expression shifts the equilibrium to the on or off state.
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Farhat, Dayana. "MORC, un régulateur épigénétique au carrefour des trajectoires développementales du parasite T. gondii A MORC-driven transcriptional switch controls Toxoplasma developmental trajectories and sexual commitment." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALV014.
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Toxoplasma gondii est l’agent pathogène responsable de la toxoplasmose, une maladie sans gravité lorsqu'elle est contractée chez un sujet immunocompétent ou en dehors d'une grossesse. Lorsqu’elle est congénitale, la toxoplasmose peut se manifester par des malformations neurologiques sévères et une atteinte de la rétine, pouvant conduire à la cécité. La toxoplasmose peut être aussi gravissime chez le malade immunodéprimé (SIDA - greffes d'organes - thérapies anticancéreuses). Les principaux modes de contamination sont d’origine alimentaire. L’homme se contamine habituellement en ingérant les kystes présents dans les viandes, ou des oocystes provenant des matières fécales d’un chat infecté et souillant les légumes, les fruits ou l’eau. Si la reproduction sexuée constitue un élément central dans la pathogénèse de la toxoplasmose et la transmission du parasite entre les animaux, cette étape clé du cycle parasitaire reste encore mal étudiée à l’échelle moléculaire, en partie dû à la difficulté à cultiver in vitro les formes sexuées ; pour des raisons évidentes d’éthique, l’utilisation de chats est quant à elle restreinte par la législation. Le destin cellulaire d’un parasite est apparemment prédéterminé par des mécanismes épigénétiques modifiant de manière réversible, transmissible et adaptative, l'expression des gènes sans en changer la séquence d’ADN. Nous avons montré que l’épi-drogue FR235222 en inhibant l’enzyme HDAC3 modifie les trajectoires développementales et promeut l’apparition dans les cultures in vitro des formes latentes et sexuées. Au cours de ma thèse j’ai étudié protéine Microrchidia (MORC), initialement identifiée comme un partenaire de HDAC3. Les protéines MORC interviennent dans la réponse aux dommages à l'ADN et la répression des transposons et bien que conservées chez les eucaryotes restent peu étudiées. Nous avons résolu l’interactome spécifique de MORC qui réunit HDAC3 mais aussi plusieurs facteurs de transcription apetala (AP2). L’immunoprécipitation de chromatine de la protéine MORC, couplée au séquençage massif (ChIP-seq), a montré que la protéine MORC co-localise parfaitement avec HDAC3 à la chromatine au voisinage de plus de 1600 gènes dont l’expression est connue pour être restreintes au stades sexués et latents (sporozoites et bradyzoite). L’épuisement de la protéine MORC de manière inductible par le système dégron induit à l’auxine (AID) confirme la répression par MORC des gènes susmentionnés et de leurs protéines. Le phénomène de transition vers les stades sexués est quasi exhaustif et très peu de gènes échappent à cette régulation par MORC. Nous avons montré que MORC est nécessaire à l’adressage à la chromatine de HDAC3, et émettons l’hypothèse que les facteurs AP2 co-purifiés apportent la spécificité de reconnaissante à l’ADN. Nos données montrent également un schéma de régulation beaucoup plus complexe puisque la déplétion de MORC dans les parasites conduit à l’induction de facteurs AP2 dits secondaires qui aurait pour mission de guider les trajectoires développementales et de garantir l’unidirectionnalité du cycle parasitaire, un élément clé de la persistance et de la transmission entre les hôtes définitifs/intermédiaires de Toxoplasma gondiiToxoplasma gondii has a complex life cycle that is typified by asexual development that takes place in vertebrates, and sexual reproduction, which occurs exclusively in felids and is therefore less studied. The developmental transitions rely on changes in the patterns of gene expression, and recent studies have assigned roles for chromatin shapers, including histone modifications, in establishing specific epigenetic programs for each given stage. Here, we identified the T. gondii microrchidia (MORC) protein as an upstream transcriptional repressor of sexual commitment. MORC, in a complex with Apetala 2 (AP2) transcription factors, was shown to recruit the histone deacetylase HDAC3, thereby impeding the accessibility of chromatin at the genes that are exclusively expressed during sexual stages. We found that MORC-depleted cells underwent marked transcriptional changes, resulting in the expression of a specific repertoire of genes, and revealing a shift from asexual proliferation to sexual differentiation. MORC acts as a master regulator that directs the hierarchical expression of secondary AP2 transcription fac- tors, and these transcription factors potentially contribute to the unidirectionality of the life cycle. Thus, MORC plays a cardinal role in the T. gondii life cycle, and its conditional depletion offers a method to study the sexual development of the parasite in vitro, and is proposed as an alternative to the requirement of T. gondii infections in cats
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Masoud, Khalid Hasan. "Circuits and controls for grid-connected inverters." Thesis, Queensland University of Technology, 2002.
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Rossek, Sacha J. "Direct optical control of a microwave phase shifter using GaAs field-effect transistors." Thesis, Middlesex University, 1995. http://eprints.mdx.ac.uk/10682/.
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The design and analysis of a novel optical-to-microwave transducer based upon direct optical control of microwave gallium arsenide (GaAs) field-effect transistor (FET) switches is the subject of this thesis. The switch is activated by illuminating the gate depletion region of the FET device with laser light having a photon energy and wavelength appropriate to the generation of free carriers (electron-hole pairs) within GaAs. The effects of light on the DC and microwave properties of the GaAs FET are explored and analyzed to permit the characterization of the switching performance and transient response of a reflective microwave switch. The switch is novel in that it utilizes direct optical control, whereby the optically controlled GaAs FET is directly in the path of the microwave signal and therefore relies on optically-induced variations in the microwave characteristics of the switch. This contrasts with previous forms of optically controlled switches which rely on indirect methods with the optical stimulus inducing variations in the DC characteristics of the GaAs FET, such that there is no direct interaction between the optically illuminated GaAs FET and the microwave signal. Measured and simulated results relating to the switching performance and transient response of the direct optically controlled microwave switch have been obtained and published as a result of this work. For the first time, good agreement is achieved between the measured and simulated results for the rise and fall times associated with the transient response of the gate photovoltaic effect in optically controlled GaAs FET switches. This confirms that the GaAs FET, when used as an optically controlled microwave switch, has a transient response of the order of several micro-seconds. An enhanced model of the GaAs FET switch has been developed, which represents a more versatile approach and leads to improved accuracy in predicting switching performance. This approach has been shown to be valid for both optical and electrical control of the GaAs FET. This approach can be used to model GaAs FET switches in discrete or packaged forms and predicts accurately the occurrence of resonances which may degrade the switch performance in both switching states. A novel method for tuning these resonances out of the switch operating band has been developed and published. This allows the switch to be configured to operate over the frequency range 1 to 20 GRz. The agreement between the models and measured data has been shown to hold for two very different GaAs FET structures. The results of the direct optically controlled microwave GaAs FET switch have been used as the basis for the design of a novel direct optically controlled microwave phase shifter circuit; Measured and simulated results are in good agreement and verify that the performance of the optically controlled phase shifter is comparable with previously published results for electrically controlled versions of the phase shifter. The 10 GRz phase shifter was optically controlled over a 1 GRz frequency range and exhibited a mid-band insertion loss of 0.15 dB. The outcome of the work provides the basis for directly controlling the phase of a microwave signal using the output of an optical sensor, with the GaAs FET acting as an optical-to-microwave transducer through a monolithic interface.
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Park, Sung Yeul. "Design and Implementation of Four-quadrant Operation in Single-Switch Based Switched Reluctance Motor Drive System." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/33985.
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In step with development of advanced, cost effective semiconductors and electrical motor drive components, the Switched Reluctance Machine (SRM) has become the center of public attention. Interest in a single-phase SRM has arisen in many places, especially because of its low cost applications. However, some drawbacks have plagued single-phase SRM: the lack of self-starting capability and restricted operation conditions.
This thesis presents a four-quadrant operation SRM drive system with a single controllable switch for two phase configuration. The SRM's configuration has four main stator poles, four rotor poles, and four auxiliary stator poles. Because of this special arrangement, a four-quadrant operation with a given power converter topology and proposed control algorithms has been realized. The focus of the paper is to realize a four-quadrant operation with a single-switch converter based SRM. In addition, this research resulted in a new self-starting scheme without adding permanent magnets. Simulation results and experimental results utilizing the control algorithm verify the performance of the system.
Master of Science
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Ogston, Elizabeth F. Y. (Elizabeth Flora Yehlan). "The Arctic switch fabric control interface system." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40172.
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Du, Yong. "Online Admission Control for Multi-Switch Ethernet Networks." Thesis, Mälardalens högskola, Inbyggda system, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-29854.
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The trend of using switched Ethernet protocols in real-time domains, where timing requirements exist, is increasing. This is mainly because of the features of switched Ethernet, such as its high throughput and availability. Compared to other network technologies, switched Ethernet can support higher data rate. Besides the timing requirements, that must be fulfilled in real-time applications, another requirement is normally demanded in real-time systems. This requirement is the ability of changing, adding or removing the messages crossing the network during run-time. This ability is known as on-line reconfiguration, and it should be done in a way that the real-time behavior of the network is not violated. This means that, the guarantee of meeting the timing requirements for the messages should not be affected by the changes in the network. In this thesis, we focus on on-line reconfiguration for multi-hop HaRTES architecture, which is a real-time switched Ethernet network. The HaRTES switch is a modified Ethernet switch that provides real-time guarantees as well as an admission control to be used for on-line reconfiguration. We study the existing reconfiguration methods including centralized and distributed approaches. Then, we propose a solution to provide on-line reconfiguration for the multi-hop HaRTES architecture, based on the studied methods. For this purpose, we use a hybrid method to achieve the advantages of both traditional centralized and distributed approaches. Moreover, we perform two different experiments. In the first experiment we focus on the decision making part of the method. The decision making part decides whether the requested reconfiguration is feasible. We calculate the time required to make the decision in different network settings. In the second experiment, we focus on the entire reconfiguration process, where the decision making is part of it. Again, we show the time needed to do the reconfiguration in several network settings. Finally, we conclude the thesis by presenting possible future works
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Lugagne, Jean-Baptiste. "Real-time control of a genetic toggle switch." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC249/document.
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Les progrès récents de la microfluidique, la biologie synthétique, la microscopie automatisée rendent aujourd'hui possible le contrôle externe de l'expression des gènes en temps réel. Parmi les défis que devra relever le domaine du contrôle externe et temps-réel de l'expression des gènes, se trouve la possibilité de contrôler des réseaux de régulation génique aux dynamiques complexes et multi-stables et le contrôle de multiples gènes en parallèle. Pour faire avancer le domaine dans cette direction nous avons étudié la contrôlabilité d'un réseau bistable composé de deux gènes, appelé genetic toggle switch, ou bascule génétique, autour de son point d'équilibre instable sur de longues périodes. Dans ce document, nous présentons la mise en place d'une plateforme de contrôle externe de l'expression des gènes en cellule unique, ainsi que le développement d'un châssis cellulaire bactérien et d'une librairie de circuits de bascules génétiques à contrôler. Nous utilisons la plateforme pour diriger et maintenir notre système génétique dans sa région d'instabilité avec des techniques de stabilisation à la fois en boucle ouverte et en boucle fermée. Nous démontrons non seulement que les plateformes de contrôle in silico peuvent être utilisées pour contrôler un système génétique dans un état hors-équilibre, nous démontrons aussi la possibilité de maintenir une population de cellules dans leur région d'instabilité à l'aide de stimulations périodiques en boucle ouverte. Ces résultats suggèrent l'émergence de régimes de stabilité différents dans des réseaux de régulation génique lorsqu'ils sont soumis à des environnements fluctuants, et peuvent fournir de nouvelles perspectives dans l'étude de la prise de décision cellulaire. Nous présentons aussi une nouvelle approche pour l'analyse d'images de microscopie qui exploite l'information cachée dans plusieurs plans focaux autour du spécimen au lieu d'utiliser seulement un seul plan focal. L'objectif de cette méthode est d'identifier automatiquement les différentes parties d'une image à l'aide de techniques d'apprentissage-machine inspirées de l'imagerie hyperspectrale. La méthode facilite la segmentation de l'image et peut être facilement adaptée à différents organismesRecent progresses in microfluidics, synthetic biology and microscopy automation now make it possible to control gene expression externally and in real time. Among the challenges facing the field of external real-time control of gene expression is the control of intricate, multistable gene regulation networks as well as the control of several target genes at the same time. To advance the domain in this direction we studied the controllability of a simple bistable two-genes network, the so-called genetic toggle switch, in the vicinity of its unstable equilibrium point for extended periods of time. Throughout this document, we present the development of a custom control platform for external control of gene expression at the single-cell level as well as a bacterial cellular chassis and a library of toggle switch genetic circuits for us to control. We use the platform to drive and maintain our genetic system in its region of unstability with both closed-loop and open-loop strategies. Not only do we demonstrate that in silico control platforms can control genetic systems in out-of-equilibrium states, we also notably maintain a population of cells in their unstable area with open-loop periodic stimulations. These results suggest the possible emergence of different regimes of stability in gene regulation networks submitted to fluctuating environments, and can potential insights in the study of cellular decision making. We also introduce a new approach for microscopy image analysis which exploits information hidden in several focal planes around the specimen instead of using only a single-plane image. The objective of this method is to automatically label different parts of an image with machine learning techniques inspired by hyperspectral imaging. The method is then shown to facilitate segmentation and be easily adaptable to various different organisms
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Teodoro, Ricardo Gouveia. "Controle da posição angular da perna de voluntários hígidos e com lesão medular utilizando estimulação elétrica funcional e técnicas de controle robusto e chaveado." Ilha Solteira, 2018. http://hdl.handle.net/11449/157347.
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Orientador: Aparecido Augusto de CarvalhoResumo: A Estimulação Elétrica Funcional tem sido utilizada para auxiliar no restabelecimento de funções motoras em paraplégicos. Neste trabalho é proposto um procedimento experimental para identificar as incertezas politópicas de um modelo dinâmico do movimento do membro inferior, produzido por estimulação elétrica aplicada no quadríceps. Foram realizadas comparações entre controle em malha aberta e dois controladores em malha fechada. O projeto dos controladores foi baseado em desigualdades matriciais lineares (LMIs). Os resultados experimentais foram obtidos para 5 voluntários hígidos e 4 voluntários paraplégicos. Devido à incerteza dos parâmetros da planta, os resultados experimentais mostraram que o sinal de controle é incerto para um ponto de operação. Pela primeira vez aplicou-se controle chaveado com incerteza e estimulação elétrica para controlar o movimento do membro inferior. O controlador chaveado u_(σ,ξ) (t)apresentou o menor valor da derivada temporal da função de Lyapunov e compensou a incerteza do sinal de controle.
Abstract: Functional Electrical Stimulation has been used to aid and restore motor functions in paraplegics. In this work, we propose an experimental procedure to identify the polytopic uncertainties of a dynamic model of the lower limb movement produced by electrical stimuli applied to the quadriceps. A comparison between open-loop control and two closed-loop controllers was performed. The controller design was based on linear matrix inequalities (LMIs). Experimental results were obtained for 5 healthy volunteers and 4 paraplegic volunteers. Due to plant parameters uncertainties, the experimental results showed that the control signal is uncertain for an operating point. For the first time, a robust switched controller and electrical stimulation were applied to control the movement of the lower limb. The switched controller u_(σ,ξ) (t)presented the smallest time-derivative value of the Lyapunov function and compensated the uncertainty in the control signal.
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Thomas-Claudepierre, Anne-Sophie. "The cohesin and mediator complexes control immunoglobulin class switch recombination." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAJ112/document.
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Lors des réponses immunitaires, les lymphocytes B diversifient leur répertoire par l’hypermutation somatique (HMS) et la commutation isotypique (CI). Ces deux mécanismes sont dépendant de l’activité de « activation-induced cytidine deaminase » (AID), une enzyme qui déamine les cytosines de l’ADN en uraciles générant des mésappariements qui sont processés différemment dans le cas de l’HMS et de la CI. Au cours de la CI, le locus de la chaîne lourde des immunoglobulines subit un changement de conformation qui rapproche les promoteurs, les enhancers et les régions de switch afin de permettre la recombinaison des régions de switch. Cependant, les mécanismes moléculaires sous-jacents n’ont pas encore été identifié. Dans le but de comprendre les mécanismes de régulation d’AID, nous avons réalisé un criblage protéomique et identifié CTCF ainsi que les complexes médiateur et cohésine qui constituent des facteurs préalablement impliqués dans les interactions longues distances. Au cours de ce travail de thèse, nous avons montré que le complexe médiateur est requis pour la transcription de la région de switch acceptrice, pour l’interaction de cette dernière avec l’enhancer Eµ et pour le recrutement d’AID au locus des IgH. D’un autre côté, nous avons montré que le complexe cohésine est impliqué dans la réparation des cassures induites par AID et qu’il pourrait être impliqué dans la recombinaison des régions de switchDuring immune responses, B cells diversify their repertoire through somatic hypermutation (SHM) and class switch recombination (CSR). Both of these mechanisms are dependent on the activity of activation-induced cytidine deaminase (AID), an enzyme that deaminates cytosines into uracils generating mismatches that are differentially processed to result in SHM and CSR. During CSR, the Ig heavy chain (IgH) locus undergoes dynamic three-dimensional structural changes in which promoters, enhancers and switch regions are brought into close proximity. Nevertheless, little is known about the underlying mechanisms. To gain insight into the molecular mechanism responsible for AID regulation during CSR, we performed a proteomic screen for AID partners and identified CTCF, cohesin and mediator complexes, which are factors previously implicated in long-range interactions. We showed that during CSR, the mediator complex is required for acceptor switch region transcription, long-range interaction between the enhancer and the acceptor switch region and AID recruitment to the IgH locus whereas the cohesin complex is required for proper AID-induced breaks repair and might favor switch regions synapsis
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Koh, Hyunsoo. "Modeling and Control of Single Switch Bridgeless SEPIC PFC Converter." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/34125.
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Due to increasing concerns on the power quality, power factor correction (PFC) has become an important issue in light-emitting diode (LED) lighting applications. A boost converter is one of the most well-known PFC topologies, due to its simple circuitry, simple control scheme and small number of passive components. Even though a boost converter is recognized as a typical PFC converter, its output voltage must be higher than its input voltage. This feature is disadvantageous because the device requires an additional buck-stage for LED lighting systems.
As an alternative to the boost converter, a single-ended primary-inductor converter (SEPIC) allows output voltage to be lower or higher than the input voltage. Thus, the SEPIC converter is gaining popularity as a LED driver because it does not require additional power conversion stage. However, designing a controller to meet stability requirements and international standards is quite challenging for SEPIC converters. Additionally, if the digital controller is adopted for its built-in communication features, creating a digitally controlled SEPIC converter would be even more challenging.
This thesis focuses on the state-space averaging modeling of the SEPIC PFC converter and the design of controllers based on both analog and digital controls with precise modeling. The proposed SEPIC converter incorporates RC damping circuits to avoid the instability, and
thus the entire SEPIC converter becomes a 5th order system. Such a high-order system model was derived mathematically and verified with circuit simulator modeling. After verification of the circuit model, the controller was designed with analog transfer functions and converted to and the discrete domain for digital controller implementation. A 150-W single-switch bridgeless SEPIC PFC converter prototype was built accordingly to verify the design. In addition to the current loop controller design for stability, a feed-forward compensator for is introduced and derived for better waveform quality. Simulation results and experiment results are also presented to verify the complete controller with feed-forward compensation. The Texas Instruments (TI) digital signal processor (DSP) TMS320F28335 was adopted for digital controller implementation. For comparison purpose, the TI UC3854 controller was implemented to verify the analog controller design results.Master of Science
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Smith, Christopher Lee. "Modeling and Control of a Six-Switch Single-Phase Inverter." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/34492.
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Distributed generation for consumer applications is a relatively new field and it is difficult to satisfy both cost and performance targets. High expectations coupled with extreme cost cutting to compete with traditional technologies make converter design difficult. As power electronics mature more opportunities arise for entry into this lucrative area. An excellent understanding of converter dynamics is crucial in producing a well performing and cost competitive system.
The six-switch single-phase inverter proposed in this thesis is a prime candidate for use in single households and small businesses. Its compact size and compatibility with existing electrical standards make its integration easy. However, little work is available on characterizing the system from a controls point of view. In particular balancing the two outputs with an uneven load is a concern. This thesis uses nodal and loop analysis to formulate a mathematical model of the six-switch single-phase inverter. A non-linear time invariant model is constructed for circuit simulation; details found in real circuits are added.
A hardware-in-the-loop (HIL) configuration is used for more accurate simulation. In fact, its use makes for an almost seamless transition between simulation and hardware experimentation. A detailed explanation of the HIL system developed is presented.
The system is simulated under various load conditions. Uneven loads and lightly loaded conditions are thoroughly examined. Controllers are verified in simulation and then are tested on real hardware using the HIL system. DC bus disturbance rejection and non-linear loads are also investigated. Acceptable inverter performance is demonstrated without expensive current sensors or high sampling frequency.Master of Science
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Whitaker, Michael Peter. "Improving the control strategy for a four-switch buck-boost converter." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42125.
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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 125-126).
The four-switch buck-boost converter, such as implemented with the Linear Technology LTC3440 integrated circuit, is useful in many applications. While this topology can be highly efficient, new strategies for controlling it could decrease power losses even more. The strategy proposed for this thesis involves the use of level shifted triangle waves and high speed comparators to achieve a narrower buck-boost region than achieved in previous control IC's such as the LTC3440. Reducing the amount of operation in this regime is desirable because it is the most inefficient mode of operation of the converter. This potentially simpler solution will allow for resources to be used to improve the performance of other elements of the circuit, allowing for potential increases in efficiency.
by Michael Peter Whitaker.
M.Eng.
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Thomson, F. M. "Control of the switch from acidic to neutral fermentation in Klebsiella aerogenes." Thesis, University of Aberdeen, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.593565.
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Chapman, Heather M. "Gsx genes control the neuronal to glial fate switch in telencephalic progenitors." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1394725163.
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Raley, Jack. "Efficient DC-DC switch regulator applied iterative learning and anti-windup control /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p1457288.
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Thesis (M.S.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed November 14, 2008). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 65-66).
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Cusack, Jessy L. "Design of a High Speed Clutch with Mechanical Pulse-Width Control." Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-theses/173.
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Kinetic energy storage via flywheels is an emerging avenue for hybrid vehicle research, offering both high energy and power density compared to more established electric and hydraulic alternatives. However, connecting the high speed flywheel to the relatively low speed drivetrain of the vehicle is a persistent challenge, requiring a transmission with high variability and efficiency. A proposed solution drawing inspiration from the electrical domain is the Switch-Mode Continuously Variable Transmission (SM CVT), which uses a high speed clutch to transfer energy to a torsion spring in discrete pulses with a variable duty cycle. The greatest limitation to the performance of this system is the speed and efficiency of commercial clutch technology. It is the goal of this thesis to develop a novel clutch which meets the actuation speed, controllability, and efficiency requirements of the SM CVT, with potential for reapplication in other rotary mechanical systems with switching functionality.
The performance demands of the clutch were derived via a theoretical design case based on the performance requirements of a typical passenger vehicle, indicating the need for a sub-millisecond engagement and disengagement cycle. This is not met by any conventional clutch. Several concepts were considered across the fluid, electromagnetic and mechanical energy domains. A final concept was chosen which employs a friction disk style architecture, with normal force produced by compressing springs via an axial cam mounted to the flywheel. To control duty cycle, the cam was designed with a radially varying profile such that increasing radial position results in proportionally increasing ratio of high dwell to low dwell. Three synchronized followers are then translated radially on the cam by a control linkage. Analysis of the follower train dynamics and system stiffness were carried out to inform the design of a scaled benchtop prototype. Experimental testing was carried out to characterize the performance of the prototype. It was found that the intended functionality of the design was achieved, with discrete energy transfer accomplished via pulsing of the clutch. However, maximum efficiency was only 33% and torque capacity was only 65% of the intended 70Nm. Significant opportunity exists for improvement of the clutch performance in future research.
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Kowalczuk, Emma K. "Simulating, fabricating and characterising photoconductive microwave switches for RF applications." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/14968.
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Photoconductive microwave switches can be used in place of traditional microwave switches to reconfigure antennas and RF circuits. The switch, which consists of a silicon die placed over a gap in transmission line, is controlled by illumination via a fibre optic cable. Hence there is no requirement to design electrical biasing lines which may affect RF performance. This benefit is the main motivation behind further developing and understanding the photoconductive switch. The second motivation is the growing demand for reconfigurable antennas which necessitate certain switching requirements; one specific area of interest is in cognitive radio applications. However, in order to use such a switch in RF circuitry, the photoconductive nature of the switch must be understood. This is addressed in this thesis presenting and applying analytical equations which dictate the material properties in photoconductive silicon. These equations are then used to generate a 3D EM simulation model to investigate transmission loss in the photoconductive switch. The concept of signal planarity is investigated so as to give some insight into the best way to package the switch. In order to potentially reduce loss and facilitate a packaged device, the fabrication of the switch is investigated. Namely, the treatment of the silicon and the addition of contacts on the silicon are discussed as possible methods to improve switch performance. Lastly, linearity, power handing and switching times are presented for the photoconductive switch. This characterisation is important with regards to understanding which types of application the switch can be used in. In particular the single tone and two tone linearity of the switch is measured these values have not previously been reported for this type of photoconductive switch. The results are encouraging and support further development of the switch into a packaged product to be used in reconfigurable antennas and circuitry.
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Kotecha, Ramchandra M. "Analysis and Comparison of Popular Models for Current-Mode Control of Switch Mode Power Supplies." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1300211710.
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Carniato, Leonardo Ataide. "Robust H∞ switched static output feedback control design for linear switched systems subject to actuator saturation /." Ilha Solteira, 2019. http://hdl.handle.net/11449/183007.
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Orientador: Marcelo Carvalho Minhoto TeixeiraResumo: Este trabalho dedica-se ao estudo do problema de controle robusto envolvendo custo H∞ para sistemas lineares chaveados no tempo contínuo, sujeitos à saturação no atuador e com incertezas politópicas, considerando leis de chaveamento e controladores chaveados dependentes da saída da planta. Os métodos propostos oferecem novas condições baseadas em Desigualdades Matriciais Lineares (LMIs - do inglês, Linear Matrix Inequalities) para o projeto de controladores chaveados utilizando funções de Lyapunov dependentes de parâmetros. O método é baseado em um resultado recentemente introduzido na literatura para o projeto de controle H∞ de saída o qual evita igualdades matriciais lineares (LMEs - do inglês, Linear Matrix Equalities) e a necessidade de impor restrições nas matrizes de saída do sistema, isto é, as matrizes de saída do sistema podem ser de posto linha incompleto. Com o objetivo de estender estes resultados, a restrição de saturação no atuador é estudada. Análises teóricas e resultados de simulações mostram que os novos procedimentos são menos conservativos quando comparados a métodos publicados recentemente na literatura. No método proposto, as condições são uma classe particular de desigualdades matriciais bilineares (BMIs - do inglês, Bilinear Matrix Inequalities), as quais contêm alguns termos bilineares devido à multiplicação de matrizes por escalares. Estes termos estão relacionados à combinação convexa das matrizes de chaveamento bem como a outros parâmetros escalare... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This thesis is devoted to the study of the robust H∞ control problem of continuous-time switched linear systems subject to actuator saturation with polytopic uncertainties, considering an output-dependent switching law and a switched static output feedback controller. The proposed method offers new sufficient conditions based on linear matrix inequalities (LMIs) for designing the switched controllers using parameter-dependent Lyapunov functions. The method is based on a static output feedback H∞ control design recently presented in the literature that avoids linear matrices equalities (LMEs) and the need to impose any constraints on output system matrices, that is, the output matrices of the system are allowed to be of non-full row rank. In order to extend those results, the actuator saturation constraint is also studied. Theoretical analyses and simulation results show that these new procedures are less conservative than recent methods available in the literature. The conditions of the proposed methods are a particular class of Bilinear Matrix Inequalities (BMIs), which contain some bilinear terms as the product of a matrix and a scalar, related to a suitable convex combination and scalars parameters to provide extra free dimensions in the solution space. The hybrid algorithm Differential Evolution-Linear Matrix Inequality (DE-LMI), is proposed for obtaining feasible solutions of this particular NP-hard problem. Examples show that the proposed methodologies reduce the design ... (Complete abstract click electronic access below)
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Wong, Wai-Shuen Vincent. "Stochastic control of inter-switch handoff and location update in wireless cellular networks." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0020/NQ48739.pdf.
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Babaa, Saleh Hassan Elkelani. "High efficient interleaved boost converter with novel switch adaptive control in photovoltaic application." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2360.
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Energy conversion efficiency is an important factor for the long-term feasibility of photovoltaic systems. Significant work has been carried out into improving the effectiveness of solar arrays in recent years. In addition, there has been substantial research into novel power converter topologies for maximum energy efficiency. However, in photovoltaic applications, even the most promising power converter topologies do not necessarily guarantee optimum performance under all operating conditions. For instance, the efficiency of the power conversion stage may be excellent during periods of high irradiance, but significantly lower in poorer light conditions. This work attempts to address this problem, by seeking to achieve higher energy conversion efficiency under sub-optimal conditions. In this thesis, stand-alone photovoltaic systems using DC-DC boost converters are considered. An interleaved boost converter with novel switch adaptive control scheme is designed to maximise system efficiency over a wider range of real-time operating atmospheric conditions and with different load conditions without incurring significant additional cost.
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Motamedi-Sedeh, Ardeshir. "Speed control of switched reluctance motors." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ28241.pdf.
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Wall, Simon Robert. "Control of switched-mode power converters." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362966.
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Lin, Zhengyu. "Advanced control of switched reluctance motors." Thesis, Heriot-Watt University, 2005. http://hdl.handle.net/10399/266.
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Rinehart, Michael David. "Optimal control of controllable switched systems." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/33201.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 83-85).
Many of the existing techniques for controlling switched systems either require the solution to a complex optimization problem or significant sacrifices to either stability or performance to offer practical controllers. In [13], it is shown that stabilizing, practical controllers with meaningful performance guarantees can be constructed for a specific class of hybrid systems by parameterizing the controller actions by a finite set. We extend this approach to the control of controllable switched systems by constraining the switching portion of the control input and fixing the feedback controller for each subsystem. We show that, under reasonable assumptions, the resulting system is guaranteed to converge to the target while providing meaningful performance. We apply our approach to the direct-injection stratified charge (DISC) engine and compare the results to that of a model predictive controller designed for the same application.
by Michael David Rinehart.
S.M.
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Chumacero, Polanco Erik. "Velocity sensorless control switched reluctance motors." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA112062/document.
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Dans ce mémoire de thèse, nous présentons la conception, l'analyse de la stabilité, les simulations numériques et aussi les résultats des expérimentes concernant différents contrôleurs de vitesse mécanique du moteur à réluctance variable (MRV).Dans les deux premiers chapitres une brève description de la physique et de la construction du MRV est présenté ainsi que le problème du contrôle d'être abordé, c'est la commande de vitesse sans capteur. Il est aussi présenté l'état de l'art de ce problème et certains des solutions proposées dans d'autres travaux. On propose notre solution et on présente un petit résumé des articles scientifiques qui ont été publiés dans des magazines et des conférences.Dans le chapitre numéro trois est présenté le design du contrôleur adaptatif et sans capteur du MRV. On suppose, dans une première étape que seule la vitesse mécanique est inconnue et la stabilité exponentielle uniforme des erreurs de suivement est obtenue. Dans une deuxième étape, les conditions d'opération sont aggravées et, en plus de la vitesse, les paramètres physiques sont également supposées inconnues, la stabilité asymptotique uniforme est obtenue dans ce cas. L'estimation des paramètres du MRV est garantie grâce à la condition de persistance d'excitation. Cette commande se compose de deux boucles, une boucle interne basée sur un contrôleur de type PI2D qui est particulièrement intéressant parce qu'il est libre de modèle; cette boucle entraîne les variables mécaniques -la position et la vitesse- vers une référence désirée. Une deuxième boucle de contrôle externe prend le courant électrique vers un ' "courant de référence virtuelle" qui est généré sur la base d'une approche de partage de couple. Le contrôleur propose est testé au niveau de simulations numériques qui sont également présentés.Dans le quatrième chapitre, une nouvelle approche de modélisation du MRV est utilisée pour concevoir le contrôleur. Dans ce scénario, on suppose que l'ensemble de l'état et tous les paramètres physiques sont disponibles, cette approche est pensée pour être adapté au contrôleur basé sur observateur, recherche qui est en cours de développement. Le contrôleur est composé de deux boucles, également que celui qui a été mentionné précédemment. Ce contrôleur est sélectionné parce qu'il est approprié pour le contrôle d'équivalence vraie, qui il s'agit de remplacer les «mesures physiques» provenant d'un capteur par les «observations» provenant d'un observateur. La mise en oeuvre numérique est effectuée sur Simulink de Matlab.Enfin, dans le chapitre cinq, les résultats expérimentaux qui ont été effectués pour évaluer la performance des contrôleurs proposés -ce sont les PI2D et adaptatif PI2D pour le modèle simplifie ainsi que le PID pour le nouveau approche de modélisation- sont présentés. Dans la première partie, une brève description de la construction du banc de tests utilisé est présenté ainsi que quelques-unes caractéristiques techniques. Trois différentes profils de vitesse sont imposées à chacun des contrôleurs proposés -ce sont la tangente hyperbolique, la rampe saturée et la référence sinusoïdal- et de bonnes résultats sont obtenus en considérant que la variable contrôlée est la vitesse. Le dernier chapitre correspond aux conclusions de la recherche effectuée ainsi qu'aux travaux futursIn this thesis dissertation we present the design, stability analysis, numerical simulations and physical experiments of different controllers designed to drive the mechanical velocity of the switched reluctance motor (SRM). In the First and Second Chapters a brief description of the physics and construction of the SRM is presented, as well as the problem of control to be aboard, that is the velocity sensorless control of motors and the state of the art of this problem. The proposed solution is introduced and a summary of the published papers as well as the contribution are also presented.In the Chapter number three is presented the velocity sensorless and adaptive control of the SRM. It is assumed, in a first stage, that only mechanical velocity is unknown, uniform exponential stability of the errors is achieved in this scenario. In a second stage, conditions are stressed and in addition to the velocity, physical parameters are also assumed unknown, uniform asymptotical stability is achieved in this case and parameters estimation is guaranteed under a persistence of excitation condition. This controller consists of two loops, an internal loop based on a PI2D–type controller which is of particular interest given it is free-model; this loop drives the mechanical variables –that is position and velocity- towards a desired reference. An external control loop takes the electrical current towards a ‘’virtual” current reference which is generated based on a torque share approach. The controller is tested on numerical simulations, which are also presented.In the fourth chapter, a new approach on the modeling of the SRM is utilized to design the controller, in this scenario is assumed that the whole state and all the physical parameters are available, however this approach is thought to be suitable to observer based controller, whose ongoing research is being performed. The controller is composed by two loops, similarly to the one mentioned previously. This controller is selected because it is suitable for certainty equivalence control, that is, to substitute the “measurements” by the “observations” coming from a virtual sensor. Numerical implementation is performed on Simulink of Matlab.Finally, in the Chapter five, the experimental results carried out to evaluate the performance of the proposed controllers are presented, these are the PI2D and the adaptive PI2D controllers for the simplified model and the $PID$ controller for the novel modeling approach. In the first part, a brief description of the construction of the utilized bench is presented as well as the some technical characteristics. Three different velocity profiles were imposed to each of the overmentioned controllers –these are the so called smooth step, the saturated ramp and the sinusoidal reference- and good results, considering that the controlled variable is the velocity, were obtained. The last chapter corresponds to the conclusions of the performed research as well as to the future work
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El-Rifai, Khalid 1979. "Robust adaptive control of switched systems." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/39897.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (leaves 141-149).
In this thesis, robust adaptive controllers are developed for classes of switched nonlinear systems. Switched systems are those governed by differential equations, which undergo vector field switching due to sudden changes in model characteristics. Such systems arise in many applications such as mechanical systems with contacts, electrical systems with switches, and thermal-fluidic systems with valves and phase changes. The presented controllers guarantee system stability, under typical adaptive control assumptions, for systems with piecewise differentiable bounded parameters and piecewise continuous disturbances without requiring a priori knowledge on such parameters or disturbances. The effect of plant variation and switching is reduced to piecewise continuous and impulsive inputs acting on a Bounded Input Bounded State (BIBS) stable closed loop system. This, in turn, provides a separation between the robust stability and robust performance control problems. The developed methodology provides clear guidelines for steady-state and transient performance optimization and allows for parameter scheduling and multiple model controller adjustment techniques to be utilized with no stability concerns. The results are illustrated for various systems including contact-based robotic manipulation and Atomic Force Microscope (AFM) based nano-manipulation.
by Khalid El Rifai.
Ph.D.
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Castellucci, Francesca Marie. "An Exploratory Biomechanical Analysis of the Side-to-Side Swing Patterns of Three Skilled Switch Hitters." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/610.
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The ability to successfully switch hit, or hit a baseball from both sides of the plate, requires a great amount of practice and coordination bilaterally. This study used three-dimensional kinematic and kinetic data to examine the swing patterns of skilled switch hitters in baseball. Three male minor league and division I collegiate switch hitters participated. Subjects stood on force plates and hit baseballs off a tee while their swings were recorded with a three-dimensional optical motion capture system. Each subject performed twenty total swings, ten from the right and ten from the left. The swings were digitally analyzed and the dependent measures were compared side-to-side. The swing was broken down into specific events and temporal phase parameters were obtained. Peak vertical ground reaction force of each foot and stride length of each swing were also obtained. All variables were statistically analyzed using paired t-tests. The subjects displayed surface swing characteristics side-to-side that appeared identical and statistically there were no significant differences in the swing variables side-to-side. However, each subject had slight internal pattern differences side-to-side that are reported and discussed. Switch hitters are an excellent example of skilled practitioners that can provide insight into questions pertaining to dominance and motor control. Further research is needed with more subjects to explore side-to-side similarities and differences in well-established patterns.
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Kjaer, Philip Carne. "High-performance control of switched reluctance motors." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362954.
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Lopez, Gabriel Gallegos. "Sensorless control for switched reluctance motor drives." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284639.
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Akyürek, Emre. "Remote-controlled ambidextrous robot hand actuated by pneumatic muscles : from feasibility study to design and control algorithms." Thesis, Brunel University, 2015. http://bura.brunel.ac.uk/handle/2438/11671.
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This thesis relates to the development of the Ambidextrous Robot Hand engineered in Brunel University. Assigned to a robotic hand, the ambidextrous feature means that two different behaviours are accessible from a single robot hand, because of its fingers architecture which permits them to bend in both ways. On one hand, the robotic device can therefore behave as a right hand whereas, on another hand, it can behave as a left hand. The main contribution of this project is its ambidextrous feature, totally unique in robotics area. Moreover, the Ambidextrous Robot Hand is actuated by pneumatic artificial muscles (PAMs), which are not commonly used to drive robot hands. The type of the actuators consequently adds more originality to the project. The primary challenge is to reach an ambidextrous behaviour using PAMs designed to actuate non-ambidextrous robot hands. Thus, a feasibility study is carried out for this purpose. Investigating a number of mechanical possibilities, an ambidextrous design is reached with features almost identical for its right and left sides. A testbench is thereafter designed to investigate this possibility even further to design ambidextrous fingers using 3D printing and an asymmetrical tendons routing engineered to reduce the number of actuators. The Ambidextrous Robot Hand is connected to a remote control interface accessible from its website, which provides video streaming as feedback, to be eventually used as an online rehabilitation device. The secondary main challenge is to implement control algorithms on a robot hand with a range twice larger than others, with an asymmetrical tendons routing and actuated by nonlinear actuators. A number of control algorithms are therefore investigated to interact with the angular displacement of the fingers and the grasping abilities of the hand. Several solutions are found out, notably the implementations of a phasing plane switch control and a sliding-mode control, both specific to the architecture of the Ambidextrous Robot Hand. The implementation of these two algorithms on a robotic hand actuated by PAMs is almost as innovative as the ambidextrous design of the mechanical structure itself.
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Ai, Yong. "Approach to control, protect and switch charge transport through molecular junctions and atomic contact." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC125/document.
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Ces dernières décennies, l'électronique moléculaire a suscité un intérêt croissant. La construction de jonctions métal / molécules / métal est une étape fondamentale dans la compréhension de ce domaine. Nous avons été témoins d’avancées importantes concernant les jonctions moléculaires tant sur le plan théorique que sur le plan expérimental. Cette thèse se concentre principalement sur l'étude du transport de charge à travers les jonctions moléculaires. Des polymères conducteurs et des filaments de cuivre ont été déposés, par électrochimie avec un microscope électrochimique à balayage (SECM), entre une pointe et une électrode substrat. Ainsi, nous avons développé une nouvelle façon de réaliser des contacts atomiques et des jonctions moléculaires permettant de contrôler, d’activer et de protéger ces systèmes.La fabrication de jonctions à grille redox de polymères conducteurs, tel que le PEDOT et le PBT, a été effectuée dans l’intervalle micrométrique séparant les deux électrodes du SECM. Ces nano-jonctions, hautement stables et réversibles, ont montré des conductances de 10-7-10-8 S dans leur état conducteur. Ces résultats, liés à la croissance du polymère, donnent à penser que la conductance de l'ensemble de la jonction est régie par 20 à 100 oligomères.Afin d’obtenir des nano-jonctions de manière contrôlée, une méthode combinant la stratégie dite « Break Junction » (BJ) et le SECM a été mise en place. Une nano-jonction peut être obtenue en éloignant la pointe de sa position initiale. Les variations de conductance obtenues ont montré que des jonctions moléculaires au PEDOT peuvent être brisées par paliers. Des paliers de conductance ont été mesurés par SECM-BJ, et sont comparables à ceux observés par des approches STM-BJ classiques. La technique SECM-BJ s’est avérée efficace pour la fabrication et l’étude de jonctions moléculaires de polymères à grille redox. Le SECM permet également de réaliser des nano-jonctions en utilisant une stratégie d'auto-terminaison. La croissance du polymère peut être arrêtée dès que quelques brins de polymère relient les deux électrodes initialement séparées. La taille de la jonction peut donc être contrôlée par cette méthode. Les jonctions au PTFQ et PFETQ ont montré des propriétés de transport ambipolaires. Lorsque les jonctions sont constituées de plusieurs fibres, un déséquilibre dans le transport est observé entre canaux de type p- et n-. Au contraire, un équilibre est mis en évidence lorsque les jonctions atteignent une taille nanométrique. Nous attribuons cet effet à un mécanisme de transport qui passe d’un régime diffusif (loi d’Ohm) à un régime balistique (quantique) lorsque les dimensions du dispositif deviennent nanométriques.Par ailleurs, le comportement d’électrodes d’ITO avec des nanoparticules d’or (Au NPs/ITO) dénote la présence de plasmons localisés de surface (LSP). Ces substrats ont été utilisés, sous irradiation lumineuse, pour activer la jonction démontrant ainsi que la résonance plasmon peut induire une réduction électrochimique. La diminution de conductance observée peut être attribuée à des électrons chauds générés par les plasmons sur les nanoparticules d’Au piégées dans la jonction de PEDOT, réduisant celui-ci en un état isolant.Enfin, des nano-fils de cuivre ont été élaborés par SECM en utilisant un procédé électrochimique. L’étude du transport a permis de suivre la formation de ces fils entre des électrodes asymétriques. Une étude similaire a été conduite sur une électrode constituée d’un film de silice mésoporeuse sur ITO. Les films ont une épaisseur de 115 nm et les filaments de cuivre sont protégés par encapsulation dans des canaux poreux verticaux d’environ 3 nm de diamètreMolecular electronics has attracted increasing interest in the past decades. Constructing metal/molecules/metal junctions is a basic step towards the investigation of molecular electronics. We have witnessed significant development in both experiment and theory in molecular junctions. This thesis focuses mainly on the study of charge transport through molecular junctions. Conducting polymers and copper filaments were electrochemically deposited with a scanning electrochemical microscope (SECM) configuration between a tip and a substrate electrode. In doing so, we have developed a new way to fabricate atomic contact and molecular junctions, and we have explored the possibility to control, protect and switch these systems.Firstly, SECM, where two microelectrodes are located face-to-face separated by a micrometric gap, has been successfully used for the fabrication of redox-gated conducting polymers junctions, such as PEDOT and PBT. Highly stable and reversible redox-gated nano-junctions were obtained with conductance in the 10-7-10-8 S range in their conducting states. These results, associated with the wire-like growth of the polymer, suggest that the conductance of the entire junction in the conductive state is governed by less than 20 to 100 oligomers.Secondly, to obtain the nano-junctions in a controllable way, a break junction strategy combined with the SECM set up is adopted. A nano-junction could be acquired by pulling the tip away from its initial position. And conductance traces showed that PEDOT junctions can be broken step by step before complete breakdown. Similarly as STM-BJ conductance steps were observed on a PEDOT molecular junction before break down by using SECM-BJ. SECM break junction technique proved to be an efficient way of molecular junction fabrication studies, especially for redox gated polymer molecular junctions. Moreover, a self-terminated strategy is found to be another way to obtain nano-junctions. An external resistance connected to the electrode plays an important role in controlling the size of conducting polymer junctions.PFTQ and PFETQ molecular junctions exhibit well-defined ambipolar transport properties. However, an unbalanced charge transport properties in n- and p- channel for these two polymer junctions was observed when the junctions are in the fiber device scale. In contrast, when molecular junction changes into nano-junction, a balanced n- and p-channel transport property is acquired. We propose that such effect is due to charge transport mechanism changing from diffusive (ohm’s law) to ballistic (quantum theory) when the junction size is reduced from fiber devices to nanodevices.High stable Au NPs/ITO electrodes exhibit a well localized surface plasmon (LSP) behavior. These plasmonic substrates have been successfully used to trigger switching of molecular junctions under light irradiation, demonstrating that surface plasmon resonance can induce electrochemical reduction. Such conductance reduction can be attributed to the hot electrons plasmonically generated from gold nanoparticles trapped into the PEDOT junction, resulting in PEDOT being reduced and changed to an insulating state.Finally, copper metallic nanowires were generated using an electrochemical self-terminated method based on SECM configuration. The presence of a few atoms that control the electron transport highlights the formation of metallic nanowires between the asymmetric electrodes. Furthermore, a similar study was performed on mesoporous silica film on ITO used as a substrate electrode. The mesoporous silica films have vertically aligned channels with a diameter of about 3 nm and a thickness of 115 nm, which play a crucial role in protecting the copper filament
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Zhuo, Shengrong. "Control of interleaved DC-DC converter with switch fault consideration for fuel cell application." Thesis, Bourgogne Franche-Comté, 2020. http://www.theses.fr/2020UBFCA018.
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La pile à combustible, en raison de son faible niveau de tension de fonctionnement et de sa caractéristique volt-ampèremétrique non linéaire, nécessite la présence d’un convertisseur statique de type DC-DC pour la relier à la charge dans le but d’augmenter le niveau de tension et de réguler cette dernière à une valeur constante. Le convertisseur DC-DC du type hacheur élévateur à phases parallèles et à commandes entrelacées est un choix intéressant de part une conception assez simple, une bonne fiabilité, une faible ondulation du courant d'entrée, ce qui est bénéfique pour le fonctionnement à long terme de la pile à combustible. Cependant, le contrôle de cette topologie de convertisseur doit prendre en compte certains critères comme les incertitudes de valeurs au niveau des composants passifs (résistance parasite et tolérance d'inductance / capacité) et des perturbations de l’association pile à combustible – convertisseur – charge (variations du courant de charge et de la tension de la pile à combustible selon le point de fonctionnement envisagé et prise en compte des défauts électriques internes au convertisseur). Dans le but d'améliorer les performances statique et dynamique du système pile à combustible en modes de fonctionnement sain et défaillant, la commande du convertisseur à phases parallèles et à commandes entrelacées avec prise en compte de la robustesse face aux perturbations internes et externes est étudiée dans cette thèse.Pour mieux gérer les incertitudes liées aux paramètres électriques du convertisseur et les perturbations externes (pile à combustible ou charge), un contrôleur de tension robuste basé sur un observateur d'état étendu (ESO) dans le cadre de l'algorithme de contrôle actif du rejet de perturbation (ADRC) est proposé et appliqué à la topologie de convertisseur envisagée pour une application pile à combustible. La comparaison avec le contrôleur du type PI montre que la méthode proposée peut obtenir une meilleure capacité de rejet des perturbations sans dépassement de la réponse à la suite d’un échelon du courant de charge ou à une variation du niveau de tension d’entrée. Le contrôleur proposé est également validé sur une seconde topologie de convertisseur qui est une variante de la première et permettant un gain d’élévation en tension plus élevé.L’apparition d’un défaut électrique sur les interrupteurs de puissance du convertisseur entraîne généralement la perte d’une phase de celui-ci. Ceci occasionne des effets néfastes considérables sur les performances du contrôleur. Par conséquent, un contrôleur adaptatif amélioré, avec la prise en compte des défauts électriques sur les interrupteurs est proposé sur la base du contrôleur développé précédemment. Le contrôleur proposé peut maintenir un fonctionnement continu et obtenir de bonnes performances en cas de défauts. De plus, une méthode de diagnostic basé-modèle de défauts d’interrupteurs de puissance en s’appuyant sur un observateur de mode glissant est proposée et appliquée au système pile à combustible étudié. L'approche proposée dans ce manuscrit permet de diagnostiquer efficacement un défaut d’interrupteur de puissance et de montrer une forte robustesse à l'incertitude des paramètres du convertisseur et aux perturbations externes. Enfin, pour optimiser l'ondulation du courant d'entrée élevée à la suite de la perte d’une phase du convertisseur provoquée par un défaut sur l’un des interrupteurs, une nouvelle méthode de reconfiguration de la commande en appliquant une adaptation du déphasage entre les phases restantes est proposé. En comparaison avec une reconfiguration classique par un déphasage uniforme entre les phases, celle proposée permet une réduction significative de l'ondulation du courant d’entrée après l’apparition, la détection et la reconfiguration d’un défaut. Les différentes méthodes proposées sont toutes validées par des résultats de simulation et expérimentauxThe relatively low voltage and the nonlinear volt-ampere curve of the fuel cell (FC) stack necessitate the interface with the DC-DC power converter, in order to boost and regulate a constant DC bus voltage to satisfy the load requirement. The multi-phase interleaved converter by associating basic converter units via parallel structure is an attractive choice. It features high reliability, and it enables a low input current ripple via phase interleaving, which is beneficial for the long-time operation of the FC stack. The converter for FC application suffers from the converter uncertainties (parasitic resistance and inductance / capacitance tolerance), the external disturbances (dynamic load demand on the output side and variable source voltage on the input side), and the device fault (e.g., switch fault) uncertainty. Aiming to improve the steady-state and dynamic performance under healthy and switch fault mode of the system, the control of the interleaved converter with switch fault consideration for FC application is studied in this thesis.To better deal with the converter uncertainty and external disturbance, a robust voltage controller based on extended state observer (ESO) within the framework of active disturbance rejection control (ADRC) algorithm is proposed and applied to an interleaved boost converter for FC application. The comparison with PI control shows that the proposed method can achieve better disturbance rejection ability without overshoot in step response. The application of the proposed method to another interleaved converter (i.e., floating interleaved boost converter, FIBC) validates again its feasibility.The switch fault generally leads to the loss of the phase of the interleaved converter, which has considerable adverse effects on the controller performance. Therefore, an improved adaptive controller is proposed and applied to a FIBC with switch fault consideration, based on the previously developed controller. The proposed controller adapts the parameter in real-time. It can maintain continuous operation and achieve good performance in both healthy and switch fault mode. Furthermore, a switch fault diagnosis method based on sliding mode observer is proposed and applied to the FIBC for FC application. The proposed approach can diagnose the switch fault effectively, and it shows strong robustness to the converter uncertainties and external disturbances. Finally, to optimize the undesired high input current ripple of the FIBC caused by the switch fault, a novel post-fault control method by applying uneven phase shift reconfiguration is proposed. In comparison with the even phase shift reconfiguration, the proposed one can achieve significant improvement in reducing the post-fault current ripple. The effectiveness of the proposed methods is validated by the simulation and experimental results
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Santos, Guilherme Cavalari 1990. "Controle via realimentação de estado de sistemas afins com comutação a tempo contínuo." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265821.
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Orientador: Grace Silva DeaectoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
Made available in DSpace on 2018-08-27T00:51:44Z (GMT). No. of bitstreams: 1 Santos_GuilhermeCavalari_M.pdf: 16424850 bytes, checksum: 7f2f16f9c4c4f920f928c8d19273978a (MD5) Previous issue date: 2015
Resumo: Esta dissertação trata do projeto de controle H2 e Hoo via realimentação de estado para sistemas afins com comutação a tempo contínuo. Nosso objetivo principal é projetar um conjunto de ganhos de realimentação de estado e uma função de comutação assegurando estabilidade assintótica global do ponto de equilíbrio desejado. Este ponto deve pertencer a um conjunto de pontos de equilíbrio atingíveis a ser determinado. Além disso, o projeto deve levar em conta índices de desempenho H2 e Hoo que são adequadamente definidos. Para o projeto de controle Hoo, duas funções de comutação são propostas e discutidas. A primeira delas depende somente do estado, enquanto a segunda representa uma nova proposta que é mais geral e depende também da entrada externa. As condições obtidas são menos conservadoras do que as técnicas recentes disponíveis na literatura, por exemplo, os métodos baseados na função de Lyapunov do tipo máximo e os utilizados normalmente para assegurar estabilidade prática. Exemplos numéricos ilustram os resultados teóricos obtidos e são usados para comparações
Abstract: This Master's thesis deals with state feedback H2 and Hoo control design of continuous-time switched affine systems. Our main goal is to design a set of state feedback gains and a switching function assuring global asymptotical stability of a desired equilibrium point. This point must belong to a set of attainable equilibrium points to be determined. Moreover, the design must consider H2 and Hoo performance indexes to be defined. For the Hoo control design, two different switching functions are proposed and discussed. The first one depends only on the state and the other depends on the state and on the external input. The conditions are less conservative than the techniques available in the literature to date, as for instance, those based on a max-type Lyapunov function and those commonly used to assure practical stability. Numerical examples illustrate the theoretical results and are used for comparisons
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Mecânica
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Sakurai, Atsuhiko. "Sliding mode control of switched reluctance motors." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63026.pdf.
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Stewart, M. V. "Echo control for packet-switched digital telephony." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395208.
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Lewin, Paul Leonard. "Microprocessor control of a switched reluctance motor." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262359.
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Chiu, Yun-Che, and 邱韻哲. "Development of a Flyback Switch Mode Rectifier anf Its Switching Controls." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/98952630646998636365.
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碩士國立清華大學
電機工程學系
95
This thesis presents the development of a single-stage flyback switch-mode rectifier (SMR) and performs the comparative study of two current-mode control approaches. The general issues concerning power quality, survey of existing SMR circuits and current mode control methods are first explored. Then the analysis, design, implementation and control of a flyback SMR under discontinuous conduction mode (DCM) are made. For facilitating the circuit component design, the ratings of flyback SMR circuit components are derived in detail. As to the dynamic control studies, the average current control using switch current is first made. Then a varying-frequency charge-regulated approach is developed. Wherein the switch turn-on time is fixed and the off time instant is determined by the low-pass filtered switch current and the current command generated from the outer voltage loop. No dynamic current control and slope compensation are needed. The proposed control scheme possesses the advantages of having dispersedly distributed harmonic spectrum, robust current tracking control, ease of implementation using off-the-shelf integrated circuits, etc. In voltage control loop, the dynamic model is estimated. Then the quantitative feedback controller design is performed by the developed design procedure. Some simulated and experimental results are given to demonstrate the performance of the established SMRs and the effectiveness of the developed control methods.
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Shih-HaoYe and 葉士豪. "Switch Angle Control for Switched Reluctance Motor." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/rp8jm2.
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Dias, Lino Flávio Monteiro. "Smart Switch." Master's thesis, 2014. http://hdl.handle.net/10316/40391.
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Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia da Universidade de CoimbraOs equipamentos electrónicos desempenham um papel extremamente importante no nosso quotidiano. Existe cada vez mais a necessidade de realizar o mínimo esforço em actividades diárias e rotineiras, deixando essa tarefa e gestão para sistemas inteligentes. O trabalho realizado nesta dissertação teve como objectivo principal a criação de um dispositivo electrónico enquadrado no âmbito da domótica, possível de controlar remotamente e de fácil integração em circuitos convencionais já projectados e implementados. Foi elaborado um dispositivo com um teclado de toque (touch control) que comunica via Rádio Frequência (RF), tem a possibilidade de fazer dimming em sistemas de iluminação e controla estores ou qualquer outra carga (resistiva ou indutiva) não superior a 400W. Juntamente com o dispositivo foi criada uma interface com o utilizador (programada no programa Monodevelop), aplicada a um sistema de iluminação com 2 lâmpadas que comunica através da porta USB de um computador e que pode ser compilada em diferentes sistemas operativos. Foram testados experimentalmente 2 sistemas “Smart Switch” com 2 lâmpadas cada um, onde as lâmpadas eram actuadas através da interface com o utilizador compilada para Windows.
Electronic devices play an extremely important role in our daily lives. There is a need to make the minimum effort in daily and routine activities leaving this task and management for intelligent systems. The main goal of this dissertation was the creation of an electronic device that can be fitted in home automation (domotics) that could be controlled remotely and be easily integrated in conventional installations already designed and implemented. It was designed a device with a touch control that communicates by radio frequency (RF) and has the ability to make dimming for lighting systems and control blinds or any charges (resistive or inductive) that not exceed 400W. Along with the device was created a user interface (programmed with Monodevelop) applied to a lighting system with 2 lamps that communicate by USB port of a computer and can be compiled in several operating systems. 2 Smart Switch systems were tested with 2 lamps each controlled by the user interface developed and compiled for Windows.
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Chu, Ching-Te, and 朱清德. "Multiple Models Switch Adaptive Control." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/26086046115695981538.
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碩士大同工學院
機械工程學系
84
Because of the slow parameter adaptation of the adaptive control law, the poor transient response generally exists. The main objective of this researchis to improve the transient response of adaptive system. The method for improving transient response is to make use of the multiple models, that is, estimating system parameters by using multiple models, selecting the model which estimates best according to appropriate performance index, and then usingthe controller to control the plant which corresponds to that identification model. By tis way, the transient response of adaptive system is improved. Note that the initial estimates of plant parameters are uniformly distributed in thecompact set that plant parameters exist. This research applies the "composite adaptation" concept which extracts information about parameters from all sources that contain it and uses a different adaptive law. We hope to obtain better transient response of adaptivesystem by using a different adaptation law. From the simulation results, it is known that multiple models and switch iseffective to improve the poor transient response of adaptive system and by using the composite adaptation law, we obtain better transient response.
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Kamga, Morgan. "Congestion control in packet switch networks." Thesis, 2008. http://hdl.handle.net/10539/5884.
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We consider a congestion control problem in computer networks. The problem
is posed as an optimal control problem and reduced to a problem of
finding solutions to delay differential equations. Systems involving time delays
in the dynamics are actually very difficult to model and therefore very
difficult to solve. We consider three approaches in our congestion control
problem: an elastic queue approach leading to an optimal control problem
with a state–dependent delay differential equation; three approaches in flow
models (also leading to systems containing delay differential equations), precisely
the dual control approach, the primal–dual control approach and the
control approach based on queueing delay. The elastic queue approach is not
explored due to the lack of software good enough to solve optimal control
problems involving delay differential equations.
In flow models, we consider the standard case, that is where the feedback
from sources to links is exact and the network behaves perfectly well (without
any unexpected event). We also consider some non–standard cases such as
the case where this feedback contains errors (for example overestimation,
underestimation or noise), and the case where one link breaks in the network.
We numerically solve the delay differential equations obtained and use the
results we get to determine all the considered dynamics in the network.
This is followed by an analysis of the results. We also explore the stability
of some simple cases in the dual control approach, with weaker conditions
on some network parameters, and discuss some fairness conditions in some
simple cases in all the flow model approaches. Non–standard cases are also
solved numerically and the results can be compared with those obtained in
the standard case.