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Maître, Apolline. "Modulating the vector microbiota for the control of vector-borne pathogens." Electronic Thesis or Diss., Maisons-Alfort, École nationale vétérinaire d'Alfort, 2024. http://www.theses.fr/2024ENVA0005.
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Le cheptel corse, composé d'ovins, de caprins, de porcins et de bovins, est principalement élevé dans des systèmes d'élevage extensifs. Les interactions fréquentes entre le bétail, la faune sauvage et les populations humaines favorisent donc la circulation des tiques et des micro-organismes transmis par les tiques. Une forte prévalence de bactéries transmises par les tiques des familles Rickettsiaceae et Anaplasmataceae a été signalée chez les chèvres (Anaplasma ovis), les moutons (A. ovis), les bovins (Anaplasma marginale, Anaplasma phagocytophilum et Ehrlichia minasensis) et les tiques (Rickettsia spp.) en Corse. Certaines de ces bactéries (par exemple, A. phagocytophilum et Rickettsia sp.) sont zoonotiques et pathogènes pour l'homme. Actuellement, il n'existe pas de mesures préventives pour le contrôle des tiques et des maladies transmises par les tiques. Le microbiome des tiques est un ensemble très complexe de micro-organismes en interaction qui ont un impact sur la physiologie des tiques et leur compétence vectorielle. Récemment, nous avons montré que les vaccins anti-microbiote des tiques peuvent produire une mortalité élevée chez celles-ci pendant leur alimentation. Les vaccins anti-microbiotiques peuvent également moduler le microbiome des tiques et peuvent donc être utilisés comme outil de contrôle de la transmission des pathogènes transmis par les tiques. Dans ce projet, nous utiliserons le séquençage de nouvelle génération des amplicons 16S pour étudier la diversité taxonomique et fonctionnelle du microbiome de Rhipicephalus bursa et Hyalomma marginatum, les principales tiques vectrices de pathogènes chez le bétail en Corse. En utilisant les réseaux de co-occurrence et la détection à haut débit des pathogènes, nous identifierons ensuite les bactéries clés interagissant avec les pathogènes détectés transmis par les tiques. Les bactéries clés de voûte seront utilisées pour formuler des vaccins anti-microbiotiques afin de bloquer l'acquisition et/ou la transmission des pathogènes<br>The Corsican livestock population, composed of sheep, goats, pigs and cattle, is mainly raised in extensive farming systems. Frequent interactions between livestock, wildlife and human populations can favor the circulation of ticks and tick-borne microorganisms. A high prevalence of tick-borne bacteria of the families Rickettsiaceae and Anaplasmataceae has been reported in goats (Anaplasma ovis), sheep (A. ovis), cattle (Anaplasma marginale, Anaplasma phagocytophilum, and Ehrlichia minasensis) and ticks (Rickettsia spp.) in Corsica. Some of these bacteria (e.g., A. phagocytophilum and Rickettsia sp.) are zoonotic and pathogenic to humans. Currently, there are no preventive measures for the control of ticks and tick-borne diseases. The tick microbiome is a very complex set of interacting microorganisms that impact tick physiology and vector competence. Recently, we have shown that tick microbiota vaccines can produce high mortality in ticks during feeding. Anti-microbiota vaccines can also modulate the tick microbiome and thus can be used as a tool to control the transmission of tick-borne pathogens. In this project, we will use next-generation sequencing of 16S amplicons to study the taxonomic and functional diversity of the microbiome of Rhipicephalus bursa and Hyalomma marginatum, the main pathogen-vector ticks in cattle in Corsica. Using co-occurrence networks and high-throughput pathogen detection, we will then identify keystone bacteria interacting with the detected tick-borne pathogens. The keystone bacteria will be used to formulate antimicrobial vaccines to block pathogen acquisition and/or transmission
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Payn, Martin. "Flux vector control of asynchronous machines." Thesis, University of Surrey, 1991. http://epubs.surrey.ac.uk/844608/.
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The present work introduces the dynamic induction machine model using the concept of space vector notation, and shows the fundamentals of torque production to be related to the current and flux space vector interaction. By theoretical analysis the transient response of the current and voltage fed machine is determined in terms of the machine eigenvalues, and this is confirmed using simulation techniques. The concept of torque control using the current and flux space vectors' magnitude and phase is introduced. It is shown that maintaining the flux space vector's magnitude constant is a sensible approach and that transient free torque responses are possible by controlling the current space vector magnitude and phase with respect to the flux space vector, which is termed vector control. Previously only magnitude control was realised, and this is termed scalar control. It is shown that the simplest practical vector controllers work in the rotating rotor flux space vector reference frame, generated from a dynamic machine model using current and speed/position measurements from the real machine. The major disadvantage of the parameter sensitivity of this approach is examined. To complement the theoretical analysis a practical vector controller was to be built. This was designed around a new DSP micro-controller (TMS320C14) and featured a 10 kHz sampling rate. A fully instrumented 7.5 kW test rig was also developed with the induction machine driven from a modified 1 kHz inverter. The measurement of high performance shaft torque is investigated, to allow comparisons between the theoretical and practical results. The practical work centred on the comparison of the dynamic machine model with measurements made on the real machine (torque and flux) and with the theory. These showed excellent steady state performance but the dynamic response was disappointing. The implications of the model not representing the real machine transiently are investigated.
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Erdem, Erinc. "Thrust Vector Control By Secondary Injection." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607560/index.pdf.
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A parametric study on Secondary Injection Thrust Vector Control (SITVC) has been accomplished numerically with the help of a commercial Computational Fluid Dynamics (CFD) code called FLUENT®<br>. This study consists of two parts<br>the first part includes the simulation of three dimensional flowfield inside a test case nozzle for the selection of parameters associated with both computational grid and the CFD solver such as mesh size, turbulence model accompanied with two different wall treatment approaches, and solver type. This part revealed that simulation of internal flowfield by a segregated solver with Realizable k-&<br>#949<br>(Rke) turbulence model accompanied by enhanced wall treatment approach is accurate enough to resolve this kind of complex three dimensional fluid flow problems. In the second part a typical rocket nozzle with conical diverging section is picked for the parametric study on injection mass flow rate, injection location and injection angle. A test matrix is constructed<br>several numerical simulations are run to yield the assessment of performance of SITVC system. The results stated that for a nozzle with a small divergence angle, downstream injections with distances of 2.5-3.5 throat diameters from the nozzle throat lead to higher efficiencies over a certain range of total pressure ratios, i.e., mass flow rate ratios, upstream injections should be aligned more to the nozzle axis, i.e., higher injection angles, to prevent reflection of shock waves from the opposite wall and thus low efficiencies. Injection locations that are too much downstream may result reversed flows on nozzle exit.
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Orr, Jeb S. "High efficiency thrust vector control allocation." Thesis, The University of Alabama in Huntsville, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3561548.
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<p> The design of control mixing algorithms for launch vehicles with multiple vectoring engines yields competing objectives for which no straightforward solution approach exists. The designer seeks to optimally allocate the effector degrees of freedom such that maneuvering capability is maximized subject to constraints on available control authority. In the present application, such algorithms are generally restricted to linear transformations so as to minimize adverse control-structure interaction and maintain compatibility with industry-standard methods for control gain design and stability analysis. Based on the application of the theory of ellipsoids, a complete, scalable, and extensible framework is developed to effect rapid analysis of launch vehicle capability. Furthermore, a control allocation scheme is proposed that simultaneously balances attainment of the maximum maneuvering capability with rejection of internal loads and performance losses resulting from thrust vectoring in the null region of the admissible controls. This novel approach leverages an optimal parametrization of the weighted least squares generalized inverse and exploits the analytic properties of the constraint geometry so as to enable recovery of more than ninety percent of the theoretical capability while maintaining linearity over the majority of the attainable set.</p>
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Zhang, Zaining. "Sensorless vector control for induction motors." Thesis, University of Sussex, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340849.
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Wade, Scott. "Parameter identification for vector controlled induction machines." Thesis, Heriot-Watt University, 1995. http://hdl.handle.net/10399/1311.
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Ozcelik, Eray. "Speed Sensorless Vector Control Of Induction Machine." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606063/index.pdf.
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Focus of this work is closed-loop speed control of an induction machine based on direct field-oriented control (DFOC) algorithm, using estimates of speed and flux observers which utilize only stator current and voltage. Theoretical bases of the algorithms are explained in detail and their performances are investigated with simulations and experiments.
Field Orientated Control is based on projections which transform a threephase time and speed dependent system into a two co-ordinate time invariant system. These projections lead to a structure similar to that of a DC machine control. Transformations are done in synchronous frame alligned to d-axis of rotor flux. So rotor flux position must be known accurately to make these transformations. Degined flux observer, in which voltage model is assisted by current model via a closed-loop to compensate voltage model&rsquo<br>s disadvantages, estimates the position of the rotor flux.
Obtaining adequate torque control via FOC, speed loop is closed using conventional PI regulators. Speed feedback is necessary to complete control loop. Model Reference Adaptive System is studied as a speed estimator. Reactive power scheme is applied to MRAS algorithm to estimate rotor speed.
In this study, the direct (rotor) flux oriented control system with flux and speed estimators is described and tested in real-time with the starter kit named TMS320F2812 eZdsp DSK and the Embedded Target for the TI C2000 DSP tool of Matlab
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Wilson, Anne Louise. "Integrated vector management : generation and use of evidence for more effective vector control." Thesis, Durham University, 2017. http://etheses.dur.ac.uk/12091/.
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Vector-borne diseases (VBD) such as malaria, dengue and leishmaniasis have a major public health impact primarily in low and middle income countries in the tropics. Vector control methods including long-lasting insecticidal nets and indoor residual spraying contribute substantially to control of VBDs, particularly malaria. However, progress is being hampered by a number of factors including a lack of human, infrastructural and financial resources, and is threatened by the development of insecticide resistance. The World Health Organization (WHO) strongly advocates the use of Integrated Vector Management (IVM), a policy which has the potential to overcome many of the challenges facing vector control. IVM calls for evidence-based and adaptive use of vector control tools and involvement of multiple sectors to control VBDs. This thesis brings together work on the theme of IVM and the generation and use of evidence for better vector control programming. Specifically I ask how do we develop high quality evidence to improve the effectiveness of vector control? The writer has been a principal author of a recently published WHO Toolkit for IVM in sub-Saharan Africa (Volume II of this thesis). This toolkit for vector control programme managers builds on previous WHO guidance by providing practical detail on how to plan, implement, and monitor and evaluate an IVM programme. In order to provide guidance on choice of vector control interventions in the IVM toolkit, it was necessary to systematically review the evidence from field trials of vector control tools. Two systematic reviews are presented evaluating the efficacy of insecticide-treated nets, curtains and screening against non-malaria VBDs, and the efficacy of topical repellents against malaria. These found that: i) insecticide-treated materials in the home (nets, curtains and screening) are protective against cutaneous leishmaniasis and may be protective against dengue and Japanese encephalitis, ii) topical repellents are not protective against falciparum or vivax malaria in endemic populations. Systematic reviews revealed a paucity of well-conducted efficacy studies of vector control interventions which hinders evidence-based policy-making. A critical analysis of vector control study design and conduct is presented. This analysis identified common failings with vector control trials including a lack of randomisation and blinding, poor choice of outcome measures, lack of replication, no sample size calculations and contamination between clusters in cluster-randomised trials. Many of these failings could be easily rectified to produce better quality evidence and prevent waste in research. As well as evidence-based policy making on vector control interventions, IVM calls for use of evidence throughout the lifetime of the programme through entomological and epidemiological surveillance and monitoring and evaluation to choose and target interventions, measure their effectiveness and adapt the programme over time. One entomological parameter which should be measured is insecticide resistance. A study of the spatial and temporal pattern of knockdown resistance (kdr) resistance in Anopheles gambiae s.l. in a setting of high vector control use in the Upper River Region of The Gambia is presented which found that: i) An. arabiensis was the most common member of the species complex, ii) the odds of kdr were 24 times higher in An. gambiae s.s. in villages with both IRS and LLINs and 14 times higher in villages with LLINs alone, iii) the kdr mutation was more common in mosquitoes in the second year of the study and with increasing distance from the river. The result of this work is the IVM Toolkit for sub-Saharan Africa. IVM provides a logical framework to think through vector control and advocates for a more locally tailored and adaptive approach which engages partners within and beyond the health sector. Compared to current vector control, IVM has the potential to be more effective (through evidence-based use of interventions), cost-effective (through implementation of cost effective interventions and sharing of resources across sectors), sustainable (through engagement and mobilisation of communities and the non-health sector) and ecologically sound (through the use of non-insecticide-based tools). However, there are a number of challenges to utilisation of IVM. While this thesis outlines the theoretical framework for IVM, it does not test its use by programmes, and in fact there are few good examples of IVM in practice available. Policies and organisational structures of vector control programmes are currently not in support of IVM. Lack of resources (infrastructural, human and financial) hampers implementation of this more knowledge-intensive and adaptive approach to vector control. Deeply engrained silos and lack of political support may impede partnership working within and across sectors. An increased focus on vector control in the light of the recent Zika virus disease outbreak and high-level policy changes at WHO including development of the forthcoming Global Vector Control Response should galvanise support for vector control and reorientation of programmes towards an IVM approach. IVM can be implemented if there is additional and sustained financing for vector control, an investment in human resources and infrastructure, and more commitment to working across sectors. It is important to grasp this opportunity in order to exploit fully the potential of vector control to control and eliminate VBDs in the future.
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Acheson, Emily. "Predicting Disease Vector Distributions Through Space and Time Using Environmental and Vector Control Data." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32797.
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Within this thesis, I performed a systematic review of approaches to broad-scale modelling of disease vector distributions and determined the most widely used methods predict current species niches and project the models forward under future climate scenarios without temporal validation. I then provided a forward-looking summary of emerging techniques to improve the reliability and transferability of those models, including historical calibration.
I then predicted Anopheles mosquito distributions across Tanzania in 2001 (before large-scale ITN distributions) and compared this model with countrywide ITN use by 2012 to assess where the most suitable mosquito habitats were located and whether ITN rollouts in Tanzania ensured coverage of such areas. I concluded that ITNs in Tanzania did not optimally target areas most at risk of malaria. In doing so, I provided a new approach to monitoring and evaluating vector control interventions across large spatial scales.
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張華 and Hua Zhang. "Digital vector control of forced-commutated cycloconverter drives." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B31234574.
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Celanovic, Nikola. "Space Vector Modulation and Control of Multilevel Converters." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/29164.
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This dissertation is the result of research and development of a power conditioning system for Superconductive Magnetic Energy Storage System. The dominant challenge of this research was to develop the power conditioning system that can match slowly varying dc voltage and dc current on the super conductive magnet side with the ac voltages and ac currents on the utility side. At the same time the power conditioning system was required to provide a bi-directional power flow to the superconductive magnet.
The focus of this dissertation is a three-level diode clamped dc-ac converter which is a principle part of the power conditioning system. Accordingly, this dissertation deals with the space vector modulation of three-level converters and introduces a computationally very efficient three-level space vector modulation algorithm that is experimentally verified.
Furthermore, the proposed space vector modulation algorithm is successfully generalized to allow equally efficient, real time implementation of space vector modulation to dc-ac converters with virtually any number of levels. The most important advantage of the proposed concept is in the fact that the number of instructions required to implement the algorithm is almost independent from the number of levels in a multilevel converter.
More on the side of the control of multilevel converters, the particular attention in this dissertation is paid to the problem of charge balance in the split dc-link capacitors of three-level neutral-point-clamped converters. It is a known fact that although the charge balance in the neutral point can be maintained on a line cycle level, a significant third harmonic current flows into the neutral point for certain loading conditions, causing the neutral point voltage ripple. The logical consequence of that ripple is the deteriorated quality of the output voltage waveforms as well as the increased voltage stress on the switching devices.
This was the motivation to more carefully explore the loading conditions that cause the unbalance, as well as to study the fundamental limitations of dc-link capacitor charge balancing algorithms. As a part of that work, a new model of the neutral point current in the rotating coordinate frame is developed as a tool in investigation of theoretical limitations and in providing some intuitive insight into the problem. Additionally, the low frequency ripple is quantified and guidelines are offered that can help size the dc-link capacitors.
Because the study of the neutral point balance identified the loading conditions, that under some possible system constraints, cause an unavoidable neutral point voltage ripple, a feed forward type of control method is developed next. The proposed feed forward algorithm can effectively prevent the neutral point voltage ripple from creating distortions in the converter output voltage under all loading conditions and without causing additional disturbance in the neutral point voltage. The feed forward method is developed for a sine triangle as well as for the space vector type PWM algorithm.
The simulation results that include the full dynamic model of the converter and load system validate the feed forward approach and prove that the feed forward algorithm can effectively compensate the effect of the neutral point voltage ripple. The simulation results are than experimentally verified.<br>Ph. D.
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Ashley, Patrick A. "Control power requirements for the velocity vector roll." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-12162009-020318/.
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Aleti, Kalyan Reddy. "E-quality control a support vector machines approach /." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.
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Zhang, Hua. "Digital vector control of forced-commutated cycloconverter drives /." [Hong Kong] : University of Hong Kong, 1994. http://sunzi.lib.hku.hk/hkuto/record.jsp?B1594847X.
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Healey, Russell Cameron. "Advanced induction motor models for vector controllers." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337900.
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Blasco, Giménez Ramón. "High performance sensorless vector control of induction motor drives." Thesis, University of Nottingham, 1995. http://eprints.nottingham.ac.uk/13038/.
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The aim of this research project was to develop a vector controlled induction motor drive operating without a speed or position sensor but having a dynamic performance comparable to a sensored vector drive. The methodology was to detect the motor speed from the machine rotor slot harmonics using digital signal processing and to use this signal to tune a speed estimator and thus reduce or eliminate the estimator’s sensitivity to parameter variations. Derivation of a speed signal from the rotor slot harmonics using a Discrete Fourier Transform-based algorithm has yielded highly accurate and robust speed signals above machine frequencies of about 2 Hz and independent of machine loads. The detection, which has been carried out using an Intel i860 processor in parallel with the main vector controller, has been found to give predictable and consistent results duing speed transient conditions. The speed signal obtained from the rotor slot harmonics has been used to tune a Model Reference Adaptive speed and flux observer, with the resulting sensorless drive operating to steady state speed accuracies down to 0.02 rpm above 2 Hz (i.e. 60 rpm for the 4 pole machine). A significant aspect of the research has been the mathematical derivation of the speed bandwidth limitations for both sensored and sensorless drives, thus allowing for quantitative comparison of their dynamic performance. It has been found that the speed bandwidth limitation for sensorless drives depends on the accuracy to which the machine parameters are known and that for maximum dynamic performance it is necessary to tune the flux and speed estimator against variations in stator resistance in addition to the tuning mechanism deriving from the DFT speed detector. New dynamic stator resistance tuning algorithms have been implemented. The resulting sensorless drive has been found to have a speed bandwidth equivalent to sensored drives fitted with medium resolution encoders (i.e. about 500 ppr), and a zero speed accuracy of ± 8 rpm under speed control. These specifications are superior to any reported in the research literature.
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Arruda, Mauro P. "Fluidic vector control of self-sustained oscillatory cavity jets." Thesis, Cranfield University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413396.
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Emerson, Paul Michael. "Ecology and control of the trachoma vector Musca sorbens." Thesis, Durham University, 2001. http://etheses.dur.ac.uk/3995/.
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The work described in this thesis was conducted In rural Gambia and builds a body of evidence Incriminating the fly Musca sorbens as a vector of the blinding disease, trachoma, which is caused by ocular infection with Chlamydia trachomatis. Literature on hygiene promotion, environmental change and flies and trachoma is reviewed in the context of the SAFE strategy for trachoma control advocated by the World Health Organization M. sorbens was present throughout the year in trachoma endemic communities; was responsible for the majority of fly-eye contacts; C. trachomatis DNA was found on it; and trachoma transmission dropped when they were removed from the environment. In a large cluster-randomised trial communities receiving fly control with insecticide for six months had a mean reduction in trachoma prevalence of 56% (95% Cl 19-93%; P=0.01) compared to controls and 37% (4-70%; P=0.068) fewer new prevalent cases of trachoma. Breeding media choice experiments showed that isolated human faeces were the preferred larval medium for M. sorbens and were capable of supporting the production of large numbers of adults. However, other animal faeces were also able to support M. sorbens development. This suggested that a community-based strategy to reduce the quantity of human faeces on the soil surface by providing latrines would have the effect of reducing the population of M. sorbens, and hence reduce fly-eye contact and trachoma transmission. The provision of latrines gave encouraging results, which were not statistically significant; 30% less active trachoma than controls after six months (-22-81%; P=0.210) and 28% (-5-60%; P=0.146) fewer new prevalent cases. Provision of latrines warrants further investigation as a method to control trachoma, particularly when used in conjunction with other control methods. The potential role of fly control in the SAFE strategy for trachoma control is discussed.
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Sokola, Matija. "Vector control of induction machines using improved machine models." Thesis, Liverpool John Moores University, 1998. http://researchonline.ljmu.ac.uk/4899/.
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Mbare, O. O. "Novel insecticides and application strategies for malaria vector control." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2015. http://researchonline.lshtm.ac.uk/2374462/.
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Targeting malaria vector mosquitoes outdoors has become a research priority to address residual malaria transmission. Mosquito larval source management provides an excellent and well established tool. However, there is a need to reduce the cost and effort of larviciding programmes by testing persistent larvicides that reduce the frequency of application and by exploring novel strategies of application. This thesis aimed to evaluate two larval control agents, with unique mode of actions: the self-spreading silicone-based film Aquatain Mosquito Formulation (AMF) and the pyriproxyfen-based insect growth regulator Sumilarv®. Dose-response tests and standardized field tests were conducted to assess the susceptibility of Anopheles gambiae sensu stricto and An. arabiensis to the two insecticides and determine their residual activity. Adults that survived exposure to larvicide-treated water at the larval stages were assessed for possible effects on fecundity and fertility. Both species were highly susceptible to both control agents at very low doses. Both control agents provided residual control of up to six weeks. Adults that emerged from larvicide-treated water laid fewer eggs and had low egg hatching rates. Consequently, the impact of three-weekly operational application of pyriproxyfen to habitats in the western Kenya highlands was assessed by comparing adult vector emergences from aquatic habitats in intervention and non-intervention sites. Pyriproxyfen application led to over 80% adult vector emergence inhibition from treated aquatic habitats. To assess if larvicide-treated water could serve as ‘reproductive sinks’ for gravid mosquitoes, the oviposition response of gravid An. gambiae s.s. to water treated with pyriproxyfen or surface film was tested under semi-field conditions using squares of electrocuting nets. Larvicide-treated water did not affect the pre-oviposition behaviour of gravid females. This study however did not demonstrate that ‘attract and kill’ strategies could be used for control of malaria vectors as the addition of an oviposition attractant to ponds containing larvicide-treated water did not increase the proportion of gravid females orienting towards this pond. To explore the effect of pyriproxyfen exposure on adults, individual An. gambiae s.s. and Cx. quinquefasciatus females were exposed to pyriproxyfen at seven time points around blood feeding. Fecundity and ability to transfer pyriproxyfen to an oviposition substrate 4 were studied in the laboratory. The impact of pyriproxyfen was dependent on the time of exposure. Females were nearly completely sterilized when exposure occurred around the blood meal while pyriproxyfen was only transferred by females that were exposed while gravid and close to egg-laying time. Consequently, a baiting station for gravid females was developed and semi-field experiments implemented to explore the transfer of pyriproxyfen by gravid An. gambiae s.s. from the baiting station to aquatic habitats. Horizontal transfer was observed but the extent of emergence inhibition was dependent on the distance of the habitat from the baiting station. Only the closest habitats received sufficient pyriproxyfen to control significant numbers of offspring. In conclusion, this study demonstrated great potential of the two control agents for the control of vector immature stages and adults caused by sterilizing effects of pyriproxyfen. Results suggest that they are suitable for inclusion into integrated vector management programmes for malaria control. Auto-dissemination of pyriproxyfen however, appears not to be a feasible strategy for malaria vector control.
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Wyse, Ana Paula Pintado. "Optimal control for malaria vector for a seasonal mathematical model." Laboratório Nacional de Computação Científica, 2007. http://www.lncc.br/tdmc/tde_busca/arquivo.php?codArquivo=140.
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In the Amazonian region occurs a variation in the malaria incidence, which is related to the pluviometric variation annual. The mathematical model proposed here considers this seasonality and different treatment intensities accessible to the infected people. The numerical evidence the seasonal fluctuation and the relationship between the environment temperature and treatment efficiency, showing that the temperature increase strongly affects the extrinsic latent period,reducing the healthy care efficiency. Because malaria treatment already exists it should be import. For another hand, even the investment in treatment is an efficient form to block the epidemy, it is not always sufficient, because the protozoan has been more resistent to the medicine; then scientists are creating transgenic mosquitoes refractory to malaria to couple with wild one, generating descending transgenic. To avaliate this situation, we consider here a mathematical model that describes the relatioship between these populations. Then, we formulate and solve an optimal control problem indicating how the transgenic mosquitoes should be introduced in the environment. The numerical simulations show the effectiveness of the control.<br>Na Amazônia ocorre uma variação na incidência de malária que está intimamente relacionada à variação pluviométrica ao longo do ano. O modelo matemático aqui proposto considera esta sazonalidade e diferentes intensidades de tratamento acessíveis às pessoas infectadas. Experimentos numéricos descrevem a flutuação sazonal e evidenciam uma relação inversa entre a temperatura e eficiência do tratamento, mostrando que um aumento na temperatura afeta fortemente o período latente extrínseco, reduzindo a eficiência do investimento em saúde. Como o tratamento para os infectados existe, é importante concentrar esforços nesse sentido para obter sucesso no controle da malária. Por outro lado, embora o investimento em tratamento seja uma forma eficaz de impedir a epidemia, isso nem sempre é suficiente, pois é fato que o protozoário tem se mostrado cada vez mais resistente aos medicamentos; por esse motivo, cientistas estão criando mosquitos transgênicos refratários à malária que devem acasalar com os mosquitos selvagens, gerando descendência transgência. Para avaliar esta situação, consideramos neste trabalho um modelo matemático que descreve de maneira simplificada a relação entre estas duas populações. A partir desse modelo, formulamos e resolvemos um problema de controle ótimo indicando uma forma adequada de introduzir esses mosquitos transgênicos. Experimentos numéricos mostram a eficácia do controle adotado.
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Pye, Gregory. "Precision position control of a three-phase squirrel-cage induction motor using vector control." Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357862.
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Lee, Bong-ha. "Active power system compensator with fuzzy vector controller." Thesis, Queensland University of Technology, 2002. https://eprints.qut.edu.au/36152/1/36152_Lee_2002.pdf.
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Active power compensation of reactive power and harmonic distortion caused by non-linear loads can be achieved by using a current controlled, voltage-source
inverter based compensator. The compensation technique used injected waveform control along with vector control based on instantaneous power theory allows a general purpose inverter based compensator to perform full
compensation of var, power factor and harmonic distortion and other non-linear components. Dr. Keith Hoffman has developed an instantaneous control algorithm capable of
eliminating harmonics and calculating the in-phase fundamental load current needed to supply the real power at the same time. The application of his technique to a new 'Switch State Coarse Fuzzy Vector Controller' is discussed in detail as well as the operation of the experimental system. The author has also
developed a compensator system that exhibits accurate control by using the instantaneously determined reference current compared with the supply current directly rather than using compensator current control as in previous methods. In microprocessor control applications, the power semiconductor switching speeds of a compensator is limited by the microprocessor calculation times. It is
demonstrated that simplifying the control circuit using a vector controller and reducing logic calculation times using coarse fuzzy logic control can be an effective and simple technique utilising both microprocessor and analogue based calculations. Two types of controller where investigated with one being a microprocessor-based fuzzification and the other an analogue comparator-based
fuzzification, are demonstrated and compared with each other. Results from the undertaken experiments show practical relevance of the developed instantaneous reference current vector calculator and 'Switch State
Coarse Fuzzy Vector Controller'. Useful techniques that integrate fuzzy control theory with conventional and modem control algorithms and switching strategies
are discussed in detail.
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Salehi, Arashloo Ramin. "Fault tolerant vector control of five-phase permanent magnet motors." Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/283138.
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Equipped with appropriate control strategies, permanent magnet (PM) machines are becoming one of the most flexible types of actuators for many industrial applications. Among different types of PM machines, five-phase BLDC machines are very interesting in fault tolerant applications of PM drives.
Torque improvement in five-phase BLDC machines can be accomplished by optimizing their mechanical structure or by enhancing their controlling methods. New current controllers are proposed in this thesis to improve the quality of generated torque under normal operations of five-phase BLDC machines. Proposed current controllers are based on combination of predictive deadbeat controlling strategy and Extended Kalman Filter estimation. These controllers will be the basis for accurate faulty operation of the motor.
Operation of five-phase BLDC machines under faulty conditions has also been considered in this study. To improve the generated torque under faulty conditions, both amplitude and phase angle of fundamental and third current harmonics are globally optimized for the remaining healthy phases.
Under faulty conditions, appropriate reference currents of a five-phase BLDC machine have oscillating dynamics both in phase and rotating reference frames. As a result, the implemented current controllers under these conditions should be robust and fast. Predictive deadbeat controllers are also proposed for faulty conditions of five-phase BLDC machines.
Fault tolerant five-phase BLDC machines are very interesting in automotive applications such as electrical vehicles and more electric aircraft. In addition, these devices are gaining more importance in other fields such as power generation in wind turbines. In all of these applications, the efficiency of PM machine is of most importance. The efficiency of a typical five-phase BLDC machine is evaluated in this thesis for normal and different faulty conditions.
Experimental evaluations are always conducted to verify the theoretical developments. These developments include proposed controlling methods, optimized reference currents, and simulated efficiency of five-phase BLDC machine under different operational conditions.
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Lamine, Adoum. "Vector control of induction machines considering the stray load losses." Thesis, Liverpool John Moores University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436561.
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Nguyen, Tâm Willy. "Thrust Vector Control of Multi-Body Systems Subject to Constraints." Doctoral thesis, Universite Libre de Bruxelles, 2018. https://dipot.ulb.ac.be/dspace/bitstream/2013/279469/5/contratTN.pdf.
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This dissertation focuses on the constrained control of multi-body systems which are actuated by vectorized thrusters. A general control framework is proposed to stabilize the task configuration while ensuring constraints satisfaction at all times. For this purpose, the equations of motion of the system are derived using the Euler-Lagrange method. It is seen that under some reasonable conditions, the system dynamics are decoupled. This property is exploited in a cascade control scheme to stabilize the points of equilibrium of the system. The control scheme is composed of an inner loop, tasked to control the attitude of the vectorized thrusters, and an outer loop which is tasked to stabilize the task configuration of the system to a desired configuration. To prove stability, input-to-state stability and small gain arguments are used. All stability properties are derived in the absence of constraints, and are shown to be local. The main result of this analysis is that the proposed control scheme can be directly applied under the assumption that a suitable mapping between the generalized force and the real inputs of the system is designed. This thesis proposes to enforce constraints by augmenting the control scheme with two types of Reference Governor units: the Scalar Reference Governor, and the Explicit Reference Governor. This dissertation presents two case studies which inspired the main generalization of this thesis: (i) the control of an unmanned aerial and ground vehicle manipulating an object, and (ii) the control of a tethered quadrotor. Two further case studies are discussed afterwards to show that the generalized control framework can be directly applied when a suitable mapping is designed.<br>Doctorat en Sciences de l'ingénieur et technologie<br>info:eu-repo/semantics/nonPublished
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Gulec, Mustafa Alpertunga. "Vector Controlled Elevator Drive." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12607186/index.pdf.
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In this thesis, a practical vector controlled elevator drive is presented. Indirect vector control of induction machine is investigated in theory and then implemented. Control technique is compared with scalar control and induction machine is compared with dc motor. The operation of the system depends on induction machine parameters, so how to accurately and automatically obtaining of the parameters is also presented. Finally, the elevator system is introduced, the application of this control system to the elevator system is described and a basic elevator control system is simulated.
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Bharadwaj, Aravind S. "Vector controlled induction motor drive systems." Diss., This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-06062008-172143/.
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Slater, Howard James. "Real time emulation environment for digital control development." Thesis, University of Newcastle Upon Tyne, 1997. http://hdl.handle.net/10443/925.
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Simulation is a powerful tool for developing electric drive systems. Simulations allow the designer to experiment with control algorithms and hardware systems in a safe environment. To this end simulation is becoming increasingly popular. On'-line simulation does have its limitations in that the controller developed during the simulation period has eventually to be transferred to the target processor which will operate in the actual drive system. If, however, a real-time simulation environment could be realised, then the actual controller running in the actual target processor could be included in the simulation. Therefore no translation of code would be required once the controller had been developed and tested within the simulation. This would obviously lead to a reduction in development time and eliminate any possibility of introducing errors due to the translation between the simulated and actual controllers. This thesis describes the development of such a system using a multiple digital signal processing environment. The real-time simulated drive is operated in parallel with an experimental drive to allow a direct comparison between the two. The ability of the multiple processing system to operate in real-time has allowed the whole concept of simulation to be taken a stage further by the development of a real-time power level simulator. This simulator is capable of emulating a machine and load in real-time with real level of voltage and current. It is designed to replace a real machine during the development and testing stages of drive manufacture. This Virtual Machine is a controllable source/sink which is driven by the real-time simulation, and because of this the Virtual Machine takes on the characteristics of any choice of model within the real-time simulation. Moreover, because of its ability to handle bi-directional power flow, the Virtual machine can be programmed to emulate motors or generators. The Virtual Machine also includes the emulation of loads, thus making it extremely flexible and of interest to applications such as machine tools, electric vehicles, and wind generators, to name but a few.
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Jung, Jackson H. (Jackson Hoa-Wai). "Modeling, and classical and advanced control of a solid rocket motor thrust vector control system." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12473.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1993.<br>Includes bibliographical references (leaves 119-124).<br>by Jackson H. Jung.<br>M.S.
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Vogt, Michael. "Support vector machines for identification and classification problems in control engineering /." Düsseldorf : VDI-Verl, 2008. http://d-nb.info/988654822/04.
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Reno, Margaret Mary. "Modeling transient thermal behavior in a thrust vector control jet vane." Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23074.
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Caruana, Cedric. "Sensorless vector control of cage induction machines using signal injection techniques." Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403392.
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Liu, Yu. "SLOTLESS SIX-PHASE BRUSHLESS DC MACHINE DESIGN AND STEPPING VECTOR CONTROL." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1440086585.
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Rasgon, Jason Laurence. "Wolbachia infection dynamics and applied vector-borne disease control in mosquitoes /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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Brown, Zachary Steven. "The Economics of Malaria Vector Control." Diss., 2011. http://hdl.handle.net/10161/3880.
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<p>In recent years, government aid agencies and international organizations have increased their financial commitments to controlling and eliminating malaria from the planet. This renewed emphasis on elimination is reminiscent of a previous worldwide campaign to eradicate malaria in the 1960s, a campaign which ultimately failed. To avoid a repeat of the past, mechanisms must be developed to sustain effective malaria control programs.</p><p>A number of sociobehavioral, economic, and biophysical challenges exist for sustainable malaria control, particularly in high-burden areas such as sub-Saharan Africa. Sociobehavioral challenges include maintaining high long-term levels of support for and participation in malaria control programs, at all levels of society. Reasons for the failure of the previous eradication campaign included a decline in donor, governmental, community, and household-level support for control programs, as malaria prevalence ebbed due in part to early successes of these programs.</p><p>Biophysical challenges for the sustainability of national malaria control programs (NMCPs) encompass evolutionary challenges in controlling the protozoan parasite and the mosquito vector, as well as volatile transmission dynamics which can lead to epidemics. Evolutionary challenges are particularly daunting due to the rapid generational turnover of both the parasites and the vectors: The reliance on a handful of insecticides and antimalarial drugs in NMCPs has placed significant selection pressures on vectors and parasites respectively, leading to a high prevalence of genetic mutations conferring resistance to these biocides.</p><p>The renewed global financing of malaria control makes research into how to effectively surmount these challenges arguably more salient now than ever. Economics has proven useful for addressing the sociobehavioral and biophysical challenges for malaria control. A necessary next step is the careful, detailed, and timely integration of economics with the natural sciences to maximize and sustain the impact of this financing.</p><p>In this dissertation, I focus on 4 of the challenges identified above: In the first chapter, I use optimal control and dynamic programming techniques to focus on the problem of insecticide resistance in malaria control, and to understand how different models of mosquito evolution can affect our policy prescriptions for dealing with the problem of insecticide resistance. I identify specific details of the biological model--the mechanisms for so-called "fitness costs" in insecticide-resistant mosquitoes--that affect the qualitative properties of the optimal control path. These qualitative differences carry over to large impacts on the economic costs of a given control plan.</p><p>In the 2nd chapter, I consider the interaction of parasite resistance to drugs and mosquito resistance to insecticides, and analyze cost-effective malaria control portfolios that balance these 2 dynamics. I construct a mathematical model of malaria transmission and evolutionary dynamics, and calibrate the model to baseline data from a rural Tanzanian district. Four interventions are jointly considered in the model: Insecticide-spraying, insecticide-treated net distribution, and the distribution of 2 antimalarial drugs--sulfadoxine pyramethamine (SP) and artemisinin-based combination therapies (ACTs). Strategies which coordinate vector controls and treatment protocols should provide significant gains, in part due to the issues of insecticide and drug resistance. In particular, conventional vector control and ACT use should be highly complementary, economically and in terms of disease reductions. The ongoing debate concerning the cost-effectiveness of ACTs should thus consider prevailing (and future) levels of conventional vector control methods, such as ITN and IRS: If the cost-effectiveness of widespread ACT distribution is called into question in a given locale, scaling up IRS and/or ITNs probably tilts the scale in favor of distributing ACTs. </p><p>In the 3rd chapter, I analyze results from a survey of northern Ugandan households I oversaw in November 2009. The aim of this survey was to assess respondents' perceptions about malaria risks, and mass indoor residual spraying (IRS) of insecticides that had been done there by government-sponsored health workers. Using stated preference methods--specifically, a discrete choice experiment (DCE)--I evaluate: (a) the elasticity of household participation levels in IRS programs with respect to malaria risk, and (b) households' perceived value of programs aimed at reducing malaria risk, such as IRS. Econometric results imply that the average respondent in the survey would be willing to forego a $10 increase in her assets for a permanent 1% reduction in malaria risk. Participation in previous IRS significantly increased the stated willingness to participate in future IRS programs. However, I also find that at least 20% of households in the region perceive significant transactions costs from IRS. One implication of this finding is that compensation for these transactions costs may be necessary to correct theorized public good aspects of malaria prevention via vector control.</p><p>In the 4th chapter, I further study these public goods aspects. To do so, I estimate a welfare-maximizing system of cash incentives. Using the econometric models estimated in the 3rd chapter, in conjunction with a modified version of the malaria transmission models developed and utilized in the first 2 chapters, I calculate village-specific incentives aimed at correcting under-provision of a public good--namely, malaria prevention. This under-provision arises from incentives for individual malaria prevention behavior--in this case the decision whether or not to participate in a given IRS round. The magnitude of this inefficiency is determined by the epidemiological model, which dictates the extent to which households' prevention decisions have spillover effects on neighbors. </p><p>I therefore compute the efficient incentives in a number of epidemiological contexts. I find that non-negligible monetary incentives for participating in IRS programs are warranted in situations where policymakers are confident that IRS can effectively reduce the incidence of malaria cases, and not just exposure rates. In these cases, I conclude that the use of economic incentives could reduce the incidence of malaria episodes by 5%--10%. Depending on the costs of implementing a system of incentives for IRS participation, such a system could provide an additional tool in the arsenal of malaria controls.</p><br>Dissertation
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Davenport, Mark A. "Error control for support vector machines." Thesis, 2007. http://hdl.handle.net/1911/20500.
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In binary classification there are two types of errors, and in many applications these may have very different costs. We consider two learning frameworks that address this issue: minimax classification, where we seek to minimize the maximum of the false alarm and miss rates, and Neyman-Pearson (NP) classification, where we seek to minimize the miss rate while ensuring the false alarm rate is less than a specified level a. We show that our approach, based on cost-sensitive support vector machines, significantly outperforms methods typically used in practice. Our results also illustrate the importance of heuristics for improving the accuracy of error rate estimation in this setting. We then reduce anomaly detection to NP classification by considering a second class of points, allowing us to estimate minimum volume sets using algorithms for NP classification. Comparing this approach with traditional one-class methods, we find that our approach has several advantages.
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Shao, Shih-Hang, and 邵士航. "Vector Hierarchical Control of a Ballbot." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/60695440042203681219.
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碩士<br>中華大學<br>電機工程學系碩士班<br>102<br>A ballbot is consisted of a ball, a body, and three Omni wheels which have been arranged triangle form, so the ballbot can move freely in two-dimension plane with a spinning ability at fixed point. Conventional hierarchical sliding mode control (HSMC) and cascaded sliding mode control (CSMC) are utilized to control under-actuated nonlinear systems. We modify their essential switching scheme as a simple positive constant without any switching, but we kept their structure. The fundamental subsystem is the combination of the original variable and its derivative with a positive constant. Then the next one with the other positive constant can also be created according to the cascaded structure or hierarchical structure.
Each subsystem normally is assigned with a subsystem control input which is designed to achieve a stable subsystem except a remainder containing the other subsystem control inputs. In other words, it is a nonlinear feedback to cancel all the associated nonlinear functions. We can only guarantee a stable final hierarchical or cascaded subsystem, but the stability of the original variables cannot be ensured. We start with a cascaded control (CC), two hierarchical controls (HC), and one vector hierarchical control (VHC). Then by considering the coordinate transformation, two coordinate transformation hierarchical controls (CHC) and their vector type VCHCs algorithms have also presented in the thesis. For regulation and point-to-point problems, simulations have been conducted to verify their feasibility and to compare their performance.
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Lee, Wen-Lung, and 李文龍. "Adaptive Control for Induction Motors Using Principles of Vector Control." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/40166435970034126953.
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碩士<br>中原大學<br>電機工程學系<br>87<br>On the basis of measurable rotor speed, stator current and stator voltage, the control design methodology for speed tracking and torque tracking problems of induction motors with unknown rotor resistance and loading torque is proposed in this paper. The proposed nonlinear adaptive controller is developed by integrating the design methods of a two-stage design approach and virtual desired variables. Based on the two-stage approach, the speed tracking problem is transformed to an equivalent control problem for torque tracking. The virtual desired variables include desired stator currents and desired rotor fluxes, which are naturally determined under the conditions induced from the principles for vector control.
In Chapter 3, we first consider the model of a current-fed induction motor. In the case, a measurable auxiliary signal will be introduced to relate the rotor flux error, whereby the direct feedback of the rotor flux can be avoided. Then the control inputs are chosen for the purpose of steering the state variables toward the desired ones. Under the condition of persistent excitation, this controller structure will provide the properties of asymptotic speed tracking and exponential torque tracking in physical operating conditions, whereas all of the internal signals are bounded. It is worth remarking that no explicit observer for the rotor flux will be constructed in the controller. In Chapter 4, the sliding mode controller is used to substitute the PI-controller. This will maintain good tracking performance when system uncertainty and external disturbance exists. Also, an Extended Kalman Filter is used to estimate the states that are not measurable in the practical system. The results of simulation are shown to demonstrate good transient and steady state responses of the proposed control algorithm.
Finally, we make a complete statement and theory proof. The whole induction motor speed and position control system is implemented by using a high-speed digital signal processor TMS320C31 in the dSPACE environment. An induction motor of driver module is used to achieve the control task. We can see from experiments, that these adaptive nonlinear controllers have good performances.
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Chou, Ping-Kuei, and 周炳奎. "THE VECTOR CONTROL OF INDUCTION SERVO MOTOR." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/32046536009375292433.
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Jain, Ting-Yu, and 簡廷諭. "The Implementation of a Vector Control Inverter." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/25477046337571980920.
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碩士<br>逢甲大學<br>電機工程學系<br>105<br>This thesis presents using vector control method to design a motor inverter. By formula derivation in this thesis find out that torque can be control by the current on the rotation coordinate. Because the torque of the motor can be directly control by the current, so the speed can be increase or decrease instantly. Then use SVPWM method to drive the inverter of the motor. Comparing with other control methods such as two phase conducted method or three phase conducted method, using SVPWM method has higher voltage efficiency and better performance. In this thesis, detecting rotor position by using Hall sensor then we can calculate the speed of the motor. After calculating the speed of the motor, the electrical of the rotor can be estimated. Afterwards, using SVPWM control method let the invertor drive the motor successfully. PID controller is design to maintain the constant speed of the motor, allowed the system can run stably under different load conditions.
In this thesis, a motor drive based on vector control theory is designed and implemented. Moreover, design a human interface that can monitor the motor data is also designed so that it is convenient to observe the system running situation. At last, a magnetic power meter is used to simulate different situations is under different loads and observes if the system can sustain stabilized.
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Su, Ya-Lin, and 蘇雅琳. "Solid Texture Synthesis with Vector Field Control." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/10497314112487397952.
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碩士<br>國立交通大學<br>多媒體工程研究所<br>96<br>Recently, some researches have been focusing on solid texture synthesis and most of them use three orthogonal 2D slices to synthesize solid textures. However, these methods only use the information on three 2D slices for neighborhood matching, and the information within 3D space is not used. It makes the results lost some information, and it is unable to control solid textures in the 3D space. Our method presents a new technique for generating solid textures with cube neighborhood matching. It helps us to synthesize within real 3D space. Appearance vectors are used to replace color neighborhood values. With these information-rich vectors, we can only use 8 locations acts for 5×5×5 cube structure neighborhoods. Additionally, we introduce our approach for controllable texture synthesis with vector fields for coherent anisometric synthesis.
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Wu, Ming-Jheng, and 吳明政. "Induction Motor Driver Design and Vector Control." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/28881638872586406273.
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碩士<br>國立中正大學<br>機械工程學系暨研究所<br>101<br>This thesis describes how I to creat a vector control system for an induction motor. First analyzed the model of the induction motor, and then research the viability of two control theories, scalar control and vector control. It was decided upon to use vector control. I also researched vector control theory of torque control and speed control. Then I identified the system parameters which are required in order to implement vector control. The experiments used were DC, Stall-signal phase, and no load. Finally I introduced the driver, which was designed by my department. In the implementation I used TMS320- 28335 digital signal processor (DSP) microcontroller, designed by Texas Instruments and the DSP control card which was produced by C.C.U. Auto-Control Lab. I then conducted the induction motor experiments on the driver and firmware in order to verify the feasibility of an induction motor vector control systems via a driver and DSP is acceptable.
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Echavarria, Diaz-Guardamino Ignacio. "Combining suction control and transverse jets for fludic thrust vector control." 2008. http://proquest.umi.com/pqdweb?did=1546798681&sid=15&Fmt=2&clientId=39334&RQT=309&VName=PQD.
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Thesis (M.S.)--State University of New York at Buffalo, 2008.<br>Title from PDF title page (viewed on Nov. 14, 2008) Available through UMI ProQuest Digital Dissertations. Thesis adviser: Forliti, David J. Includes bibliographical references.
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Suresh, Banoth. "Sensor Less Vector Control of Induction Motor Based on MRAS Control." Thesis, 2018. http://ethesis.nitrkl.ac.in/9892/1/2018_MT_216EE4294_BSuresh_Sensor.pdf.
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The implementation of vector control technique needs speed information of motor from the tachogenerators, incremental encoders or resolvers to measure the speed. The speed and flux sensors require careful mounting, alignment and it needs special attention to reduce the noise due to electrical phenomenon. The speed sensors require maintenance and extra space for mounting which increases size and cost of drive system in practical implementation. These problems can be eliminated by speed estimation techniques without using any external sensors in machine. It can be achieved by using Model Reference Adaptive System (MRAS) speed estimation technique. MRAS is popularly used for speed estimation to avoid the sensors like flux and speed. MRAS technique consists of two models named as adaptive and reference models. Moreover, it has one adaptive mechanism PI controller to tune the flux error zero. The error generated from these two models will estimate the speed of the induction machine. The conventional MRAS speed estimation method along with Voltage source inverter normally provides poor steady state response of torque waveform and more distortion/ripples in speed, flux and armature current of induction motor in steady state region. To overcome these drawbacks, anew method of Space Vector Pulse Width Modulation (SVPWM) is introduced here. In the present method, stator flux components are the control variables, and these flux components are resolved into reference voltage vectors based on SVPW Mtechnique. Due to this, the performance of MRAS speed estimator can be improved and speed disturbances are minimized, and also reduce the ripples present in torque and stator currents of the induction motor drive. Also, it has good tracking of rotor speed and reaches to steady state quickly as shown in simulation results carried out by MATLAB/SIMULINK.
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Yukselen, Alp. "Heat transfer modelling of thrust vector control systems." Thesis, 1986. http://hdl.handle.net/10945/21890.
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錢宣浩. "A midcourse guidance law with Thrust Vector Control." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/95955790097775964727.
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碩士<br>國立臺灣大學<br>電機工程學研究所<br>88<br>A nonlinear missile guidance controller with Thrust Vector Control(TVC) inputs for the interception of a theater ballistic missile is presented.
In this thesis, the midcourse phase of the missile is discussed, during which many non-ideal conditions must be considered, such as variation of the inertia of the missile and the aerodynamic force, and the controller is designed according to the properties of TVC.
A 3D optimal midcourse guidance law is designed to minimize the control effort and the distance between the missile and the target without the estimation of intercept time. And the quaternion-based sliding mode attitude controller is designed to execute the attitude command and eliminate the influence of the variation of the missile’s inertia and the aerodynamic force simultaneously. The stability of the overall system is proved by Lyapunov theory.
Extensive simulations are performed to verify the validity of the overall system.
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Kuo, Ei-Lang, and 郭益郎. "Speed Sensorless Vector Control of Induction Motor Driver." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/58682933314356013189.
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碩士<br>淡江大學<br>機械工程學系<br>88<br>The objective of this thesis is to develop a sensorless speed estimator for induction motor drives. From the state equations of the induction motor, we derive the estimation algorithm of which inputs include stator currents and voltages, and rotor flux. In order to reduce the hardware burden, only currents of two phases are measured by using hardware sensors, while the voltages and rotor flux are determined by using software estimates.
For the voltage estimation, we utilize the PWM switching states that are created by a DSPC240 controller. On the other hand, a voltage model observer is used for the rotor-flux observation. Because of the insignificant variation of parameters in high frequencies, the voltage model is usually applied in high-speed operation. For the situation of low-speed operation, we propose a compensation method for the flux command. Therefore the zero-crossover speed will be quite smoothly.
There are many advantages to measure currents, voltages, and rotor flues by using estimates. We can filter out the external noise by the software estimates and increase the robustness of the system. Furthermore, the omission of the hardware sensor will simplify the system mechanism and reduce the cost price. With the estimated rotor speed, we can form a closed-loop velocity control system that will provide larger torque outputs in low-speed operation than those by a pure V/F control.
We develop the servo-controller by using TI DSPC240 to implement the sensorless speed control algorithm. The control command is sent to a power drive made by ITRI, which would regular the motion of an 1-HP induction motor. Experimental results show that the proposed estimates can efficaciously provide the rotor speed in various operational situations.
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Wei, Zi-Xuan, and 魏子軒. "Modeling and Vector Hierarchical Control of Spherical Robots." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/28975046240507248766.
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碩士<br>中華大學<br>電機工程學系碩士班<br>102<br>In this thesis, a spherical robot consisting of a spherical wheel, a body, and four Omni wheels is modeled first. We discard the essential switching scheme in the conventional hierarchical sliding mode control (HSMC) and cascaded sliding mode control (CSMC) schemes, but the cascaded and hierarchical structure have been preserved to develop new control algorithms. Without considering the coordinate transformation, a cascaded control (CC), a hierarchical control (HC), a vector hierarchical control (VHC) algorithms are proposed. At the same time, we also present a coordinate transformation hierarchical control (CHC) and two vector coordinate transformation hierarchical controls (VCHCs) algorithms by considering the coordinate transformation. For regulation and point-to-point problems, we verify their feasibility and compare their performance by simulations.
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Ho, Yu-Ta, and 何郁達. "Development of PMSM Driver Based on Vector Control." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/07832596783018578875.
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碩士<br>國立中央大學<br>機械工程研究所<br>95<br>This thesis discusses the application of space vector control and the design of permanent magnet synchronous motor (PMSM) driver. The advantages of PMSM are high power density, high efficiency and good accelerated ability. These advantages make PMSM a widely used motor.
First, researching on mathematical model of PMSM, we found that in rotating coordinate state variables are not coupling, and control structure become mot simple. The anti-windup PI controller prevents transient response from being worse when control commends saturate. Using the space vector pulse width modulation (SVPWM) method, power module creates a rotating voltage vector to drive motor.
Second, we briefly state the hardware structure of motor driver. Each part of the driver is designed according to its function separately. There are four modules that construct the motor driver. It includes carrier board, DSP module, power module and encoder module.
Finally, we implement space vector control based on digital signal processor DSP2407 on the motor driver designed by ourselves. From the results of current, speed and position control, we know the performance of this driving system is pretty well.