Дисертації: "Control strategie"

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MINELLI, MARCO. "Strategie di Controllo Avanzate per la Robotica Chirurgica." Doctoral thesis, Università degli studi di Modena e Reggio Emilia, 2022. http://hdl.handle.net/11380/1277913.

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La robotica chirurgica può essere considerata ormai una realtà consolidata in campo medico. L'esempio più eclatante è sicuramente il robot chirurgico da Vinci®, rilasciato da Intuitive Surgical quasi 20 anni fa. Si stima che, solamente nel 2012, con il da Vinci® siano stati effettuati più di 200.000 interventi chirurgici, la maggior parte dei quali per isterectomie e asportazioni di prostata. Al giorno d'oggi, la maggior parte delle operazioni chirurgiche robotizzate vengono eseguite utilizzando tecniche di teleoperazione, nelle quali i movimenti del robot vengono direttamente controllati dal chirurgo, il quale siede ed opera da una console remota. In questo tipo di operazione il robot non possiede alcuna capacità di prendere decisioni o eseguire compiti in modo autonomo. Quest'ultimo è proprio uno dei principali temi sul quale si concentra oggi la ricerca in robotica chirurgica. L'autonomia, infatti, può offrire importanti vantaggi, che includono una maggiore efficienza e ripetibilità grazie al controllo sub-millimetrico del robot, una migliore qualità di esecuzione grazie al monitoraggio di segnali biometrici in tempo reale e alla guida assistita da computer, e minori costi. Un altro fattore che ha spinto in questa direzione sono stati sicuramente gli importanti sviluppi in tema di intelligenza artificiale, che hanno caratterizzato gli ultimi decenni. Tuttavia, è necessario tenere in considerazione che rendere autonomo un sistema robotico-chirurgico apre nuove importanti sfide in termini di controllo. Il sistema deve essere infatti in grado di, ad esempio, percepire l'ambiente circostante per cooperare con altri sistemi evitando collisioni, comprendere le dinamiche dell'ambiente per interagire con esso e compensare i disturbi esterni, e rispettare tutti i vincoli necessari ad eseguire correttamente la procedura chirurgica. Un altro problema importante quando si rende autonomo un sistema di questo tipo è la raccolta dei dati necessari per l'addestramento del sistema stesso, che spesso sono pochi e difficili da acquisire. Il lavoro di questa tesi inizia ad affrontare alcuni di questi difficili problemi ed emersi nello sviluppo del progetto Europeo Smart Autonomous Robotic Assistant Surgeon. Il primo passo è stato quello di convertire una procedura laparoscopica standard in una completamente robotizzata, realizzando un'architettura di teleoperazione per applicazioni a più bracci robotici, in grado di fornire feedback visivo e feedback di forza stabile. Questa architettura è stata sviluppata specificamente per la raccolta dei dati ed è stata utilizzata per l'addestramento della parte relativa all'intelligenza artificiale. Inoltre, i risultati ottenuti sono stati estesi realizzando un'architettura di teleoperazione trilaterale volta al training. Successivamente, il lavoro si è concentrato sullo sviluppo del sistema di pianificazione e coordinamento per il controllo di più strumenti robotizzati. Il sistema proposto mira a gestire l'incertezza fornita dal modulo cognitivo e a generare un movimento autonomo sicuro e privo di collisioni. Grazie all'esperienza acquisita durante lo sviluppo delle strategie precedenti, è stata poi sviluppata un'architettura di assistenza robotica per la procedura di accesso renale durante la nefrolitotomia percutanea. L'ultimo problema affrontato in questo lavoro di tesi è stato il controllo del centro di istantanea rotazione per sistemi robotici senza centro di istantanea rotazione meccanico. L'architettura proposta considera gli effetti che questo vincolo provoca sulla dinamica del sistema e propone un controllore che mira a gestire il vincolo massimizzando flessibilità e prestazioni. Questo controllore è stato poi proposto anche all'interno di un'architettura di teleoperazione. Tutti i sistemi proposti sono stati validati sperimentalmente su set-up fisici, con l'obiettivo di verificare e confermare l'applicabilità e l'efficacia di ciascuno di essi.
Surgical robotics can be considered an established reality in the medical field. The most striking example is the release of the da Vinci® surgical system by Intuitive Surgical almost 20 years ago. It is estimated that more than 200 000 surgeries were carried out with the da Vinci® in 2012 only, most of which were for hysterectomies and prostate removals. Most robotized surgical operations are performed using teleoperation techniques, where the surgeon sits on a remote console and has complete control of the movements of the robot, without the possibility for the robot to make decisions or perform tasks autonomously. The latter is one of the main topics on which researches in surgical robotics are focused nowadays. Indeed, autonomy can give important advantages, which include increased efficiency and repeatability due to precise robot control, improved execution quality thanks to real-time biosignal feedback and computer-aided guidance, and fewer costs. The important developments that have characterized the last decades in terms of artificial intelligence have pushed even further in this direction. However, it is necessary to take into account that making a robotic surgical system autonomous opens up new important challenges in terms of control. The system must be able, for example, to perceive the surrounding environment to cooperate with other systems while avoiding collisions, understand the environment dynamics to interact with it and to compensate external disturbances, and comply with all the constraints necessary to perform the surgical procedure correctly. Another important problem when making a system autonomous is the collection of data necessary for the training of the system, which are often few and difficult to acquire. The work of this thesis starts to address some of these challenging problems arising during the development of the European-funded project Smart Autonomous Robotic Assistant Surgeon. First, a standard laparoscopic procedure was fully robotized with a teleoperation architecture providing stable force feedback and visual feedback capabilities have been proposed for multi arms systems. This architecture was specifically developed for data collection and was used for artificial intelligence training. Moreover, the results obtained have been extended for building a trilateral teleoperation architecture for training purposes. In the following, the work concentrated on developing the planning and coordination system for the control of multiple robotic instruments. The proposed system aims to deal with the uncertainty provided by the cognitive module and to generate a safe collision-free autonomous motion. Thanks to the experience acquired during the development of the previous strategies, a robotic assistance architecture for the renal access procedure during Percutaneous nephrolithotomy has been developed. The last problem addressed in the thesis is the control of the remote center of motion for robotic systems without mechanical remote center of motion. The proposed architecture considers the effects this constraint causes on the dynamics of the system and proposes a controller that aims to deal with the constraint maximizing flexibility and performance. This controller is also proposed within a teleoperation setup. All the proposed systems have been experimentally validated on physical setups, with the aim of verifying and confirming the applicability and the effectiveness of each of them.

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MENGARELLI, ALESSANDRO. "Balance and Motor Control in Dynamic Tasks." Doctoral thesis, Università Politecnica delle Marche, 2017. http://hdl.handle.net/11566/245482.

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Nella prima parte dello studio si è descritto il mantenimento dell’equilibrio in seguito a perturbazioni indotte da stimoli esterni. La risposta posturale è stata analizzata dal punto di vista dinamico, cinematico ed elettromiografico, ottenendo una descrizione completa dei meccanismi adottati per contrastare la perdita di equilibrio. Vari parametri sono stati estratti dallo spostamento del centro di pressione e del centro di massa e sulla base dell’attività muscolare acquisita mediante elettromiografia di superficie, con lo scopo di ottenere indici che correlino con le diverse caratteristiche della perturbazione. Sulla base dei dati cinematici sono state descritte le strategie posturali adottate per contrastare la perturbazione indotta, allo scopo di quantificare se differenti condizioni perturbative facciano sorgere differenti risposte, che prevedono l’uso di differenti strategie articolari. Infine il controllo dell’equilibrio è stato descritto attraverso un modello a doppio pendolo inverso, attraverso tecniche che, sebbene ben note ed impiegate in altri ambiti, risultano poco usate per la descrizione della postura in condizioni dinamiche. Nella seconda parte si è indagato il controllo della dinamica del cammino in termini di attività muscolare, acquisita su centinaia di passi consecutivi, permettendo un nuovo tipo di descrizione non basata solamente su parametri temporali ma anche sulla frequenza con cui ogni modalità di attivazione muscolare di presenta durante il cammino. I principali risultati includono la quantificazione dei pattern di co-contrazione dei flessori di caviglia e la loro ricorrenza durante il cammino. Si sono inoltre descritte le differenze legate al genere riguardanti l’attività dei principali muscoli dell’intero arto inferiore. Basandosi sui precedenti risultati si sono poi quantificate le differenze legate al genere nei pattern di co-contrazione degli antagonisti che regolano la meccanica dell’articolazione di caviglia durante il cammino.
In the first part of this work a characterization of the upright stance recovery after balance perturbation administered through external stimuli was performed. Balance response has been analyzed in dynamics, kinematics and electromyographic terms, in order to obtain a complete description of which mechanisms are employed to withstand sudden stance perturbations. A series of parameters have been extracted from center of pressure and center of mass displacement and from electromyographic signals, acquired from lower limb and trunk muscles, in order to obtain a series of indexes which can correlate with the different characteristic of perturbations. From kinematic data, a description of the postural strategies adopted to withstand perturbations has been performed, in order to observe whether different perturbation conditions evoke different responses, employing different articular joints. Eventually, a first attempt to model perturbed upright stance through a double-link inverted pendulum is proposed, applying control systems seldom employed in describing this kind of dynamic motor task. In the second part, the motor control during the walking task was described in terms of muscular activity. Myoelectric signals were acquired in hundreds of consecutive strides, obtaining a new type of description, not only in terms of temporal parameters of muscles activity but also in terms of the occurrence frequency of each muscular activation modality during gait. The main outcomes include the description of co-contraction activity between ankle flexor muscles and the assessment of the recurrence of each co-activation pattern during walking. Furthermore, a description of the whole lower limb muscles behavior was performed, aimed to the quantification of gender-based differences in muscular recruitment during gait. Then, these two aspects were joined in assessing gender-related differences in co-contraction activity of muscles which control the ankle joint mechanics during walking.

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CARFAGNA, EMILIO. "Indagine su nuove strategie di controllo per azionamenti elettrici ad alta velocità." Doctoral thesis, Università degli studi di Modena e Reggio Emilia, 2022. http://hdl.handle.net/11380/1277906.

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L'obiettivo di questo lavoro di tesi è stato quello di investigare nuove tecniche di controllo per motori elettrici progettati per lavorare ad alta velocità. Questa tipologia di motore è caratterizzata da elevate frequenze elettriche e può essere suddivisa in: motori ad altissima velocità e motori con un elevato numero di coppie polari. Nel primo caso, il motore ad altissima velocità, viene utilizzato, per esempio, per applicazioni di pompaggio e ventilazione, mentre nel secondo caso, il motore con un alto numero di coppie polari, ad esempio lo stepper ibrido (il motore presenta solitamente 50 denti rotorici), viene utilizzato per controlli di precisione. Nel campo degli azionamenti elettrici il controllo standard si basa su un regolatore proporzionale- integrale sugli anelli di corrente e velocità, ma quando il motore viene utilizzato ad alta velocità il controllo lineare diventa instabile in presenza di bassi rapporti di frequenza di commutazione fsw rispetto alla frequenza elettrica fel. Uno studio su diverse strategie di controllo per aumentare la banda passante degli anelli corrente è stato effettuato per i motori stepper ibridi partendo dalle simulazioni in ambiente Plecs e concludendo con i test sperimentali effettuati su un setup industriale. Per aumentare la tolleranza di tutto il sistema di controllo, è stato rimosso il sensore di posizione, che presenta sensibilità al rumore, è soggetto a possibili rotture e introduce maggiori costi. Il lavoro, per motori stepper ibridi, ha riguardato lo sviluppo di strategie di controllo sensorless per motori stepper ibridi in primo luogo chiudendo il controllo vettoriale rispetto all’anello di velocità, e successivamente chiudendo l’anello di posizione con una strategia ibrida tra il controllo vettoriale (per velocità medie ed elevate) e il controllo microstepping (per basse velocità e da fermo) per risolvere i problemi di osservabilità delle macchine elettriche a bassa velocità. Nuove strategie di controllo sensorless sono presentate anche per i motori a magneti permanenti interni sia per la regione di lavoro a bassa velocità usando l’iniezione di segnale in bassa frequenza per ridurre il rumore acustico, sia per la regione di lavoro in medio/alta velocità estendendo l’uso degli osservatori di flusso statorico. Oltre alle valutazioni dal punto di vista del controllo, una valida alternativa per motori ad alta velocità è rappresentata dal Current Source Inverter (CSI) singolo stadio. Il CSI, rispetto ai più diffusi Voltage Source Inverter (VSI), lavora intrinsecamente come un boost consentendo di lavorare ad alta velocità anche con tensioni di alimentazione limitate, aspetto molto interessante in applicazioni aerospaziali e di mobilità elettrica. L’attività sul convertitore ha riguardato la sintesi di una nuova strategia di controllo per eliminare il prestadio del convertitore, il controllo sensorless usando direttamente le misure delle tensioni e l’estensione delle velocità raggiungibili considerando la regione di lavoro in bassa velocità. Altro aspetto da considerare, nel controllo di macchine ad alta velocità, è il problema delle perdite nel materiale ferromagnetico che causano maggiori ampiezze delle correnti, minore efficienza e diminuzione della coppia di uscita. L’attività ha riguardato la sintesi di una nuova strategia di controllo basata sul controllo predittivo e la successiva implementazione in dSpace.
The aim of this thesis was to investigate new control techniques for electric motors designed to work at high speed. This type of motor is characterized by high electrical frequencies and can be divided into: very high speed motors and motors with a high number of pole pairs. In the first case, the very high speed motor, is used, for example, for pumping and ventilation applications, while in the second case, the motor with a high number of pole pairs, for example the hybrid stepper (the motor usually has 50 teeth rotor blades), is used for positioning control. In the field of electric drives, standard control is based on a proportional regulator-integral on the current and speed loops, but when the motor is used at high speed the linear control becomes unstable in the presence of low switching frequency ratios fsw with respect to the electric frequency fel. A study on different control strategies to increase the bandwidth of the current loops was carried out for the hybrid stepper motors starting from the simulations in Plecs environment and concluding with the experimental tests carried out on an industrial setup. To increase the tolerance of the entire control system, the position sensor has been removed, for its sensitivity to noise, possible failures and higher costs. The work, for hybrid stepper motors, involved the development of sensorless control strategies for hybrid stepper motors by first closing the vector control with respect to the speed loop, and subsequently closing the position loop with an hybrid strategy comprising vector control (for medium and high speeds) and microstepping control (for low speeds and at standstill) to solve the observability problems electrical machines at low speeds. New sensorless control strategies are also presented for internal permanent magnet motors for low speed working region using low frequency signal injection to reduce acoustic noise respect to the classical high frequency one, and for the medium/high speed working region extending the use of stator flux observers commonly adopted for surface mounted permanent magnet motors. In addition to evaluations from a control point of view, a valid alternative for high-speed motors is the single stage Current Source Inverter (CSI). The CSI, compared to the more popular Voltage Source Inverters (VSI), intrinsically works as a boost allowing to work at high speed even with limited supply voltages, a very interesting aspect in aerospace and electric mobility applications. The activity on the converter involved the synthesis of a new control strategy to eliminate the converter prestage, the sensorless control using directly the voltage measurements and the extension of the speeds that can be reached considering the working region in low speed. Another aspect to consider, in the control of high speed machines, is the problem of iron losses in the ferromagnetic material which cause greater amplitudes of the currents, lower efficiency and decrease the output torque. The activity involved the synthesis of a new control strategy based on predictive control and the subsequent implementation in dSpace.

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Vychopeň, David. "Stanovení parametrů matematického modelu řídicí jednotky spalovacího motoru." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231768.

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Master’s thesis is focused on creating a suitable methodology for determining the parameters of the electronic control unit of the engine. Discusses how the measurement of input data into the methodology, the basic description of its functions and display the resulting values. It includes evaluation of applicability of the methodologies and the real parameters when compared with the parameters established on the basis of established methodology.

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Matyáš, Ondřej. "Manažerské řídící systémy jako nástroj implementace strategie firmy." Doctoral thesis, Vysoká škola ekonomická v Praze, 2003. http://www.nusl.cz/ntk/nusl-77147.

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Management accounting research is substantially focused on the area of management control, where the concept of management control systems is used. A vivid debate among academics is held whether management accounting research is not excessively focused on management control field while decision making information support tends to be rather neglected. The aim of the thesis is to assess the contribution of the concept of management control system, its progressive potential and value added from the point of view of management accounting. In the first part, the thesis is concerned with theoretical background of management control systems and the potential of prevailing theories to conceptualize an effective management control system. In the second part, the thesis focuses on contentual analysis of the concept of management control system. Relation between management accounting and management control system is examined in particular. The thesis assesses the contribution of the concept of management control system and its progressive potential derived from the ability of this concept to describe relevant facts and links in a more suitable way, concluding that the concept of management control system is advantageous in researching the control systems of companies and their information support, because certain aspects of this concept enables to understand to researched issues at a higher qualitative level.

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Zázvorka, Tomáš. "Strategické řízení." Master's thesis, Vysoká škola ekonomická v Praze, 2012. http://www.nusl.cz/ntk/nusl-150214.

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The goal of this master's thesis is to perform a strategic analysis, to formulate a strategy on its basis and to propose the way of implementation and control of the strategy for the SAP division of the Pontech s.r.o. company and to contribute to successful implementation of strategic management system in this division and company. The thesis consists of two main parts. In the first, theroretically-metodological, part the terms and theories of strategic management and strategy are explained first and then the most common tools and methods of strategic analysis and further phases of strategic cycle i.e. formulation, implementation and control, which are used in the second, analytical, part, are mentioned. The analysis of macro and microenvironment, the analysis of internal resources and capabilities and the synthesis in the form of SWOT analysis is thus performed gradually, a strategy is formulated on that basis and after all the way of implementation and control of a strategy is performed using the principles of Balanced Scorecard system.

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Voborná, Petra. "Studie tvorby výrobní strategie." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2008. http://www.nusl.cz/ntk/nusl-221764.

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Every production unit must have a clearly determined production strategy based on the given business strategy. Today’s competitive environment is very tough and demanding and that is why each producer’s success or failure is determined by the correctly chosen productive orientation, technically advanced products and provided services, range of supply and their quality and mostly price as well. What makes firms to improve and optimize their supplies continuously is just dynamic development of the society and continuously growing consumers and users’ requirements. The keen competition on one hand makes the business more demanding, but on the other hand it brings lots of new opportunities. Looking for new ways, new procedures and management methods and especially niches in the given products and services market will bring the coveted strategy advantage. This master’s thesis deals with a change of the current production strategy in a building company, individual production aspects and improving the quality of the production process functionality itself following the objective of the firm competitiveness and business performance improvement. Within the solution I count on an ability to adapt promptly to new market requirements, I suppose that the continuing differentiation strategy will contribute to building a position of a preferential supplier of the chosen narrow market segment for large building firms in the market. Improving every production process component is the prerequisite for further development of the company.

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Viková, Miroslava. "Návrhy strategie řízení podpory prodeje firmy." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2007. http://www.nusl.cz/ntk/nusl-221550.

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This thesis deals with analyzing strategic position of energetic drinks production company. It mainly focuses on establishing a way the company can sustain and improve its current competitive position in the market. The results of the analysis in this thesis should be able to come up with measures that can help the company improve its sales promotion strategy in its area of activity – energy drinks. These measures should be the basis for its competitiveness and sustaining its position in the market.

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BADALAMENTI, Emilio. "Le specie alloctone invasive in Sicilia: caratterizzazione del fenomeno, strategie di colonizzazione e possibili strategie di contrasto." Doctoral thesis, Università degli Studi di Palermo, 2014. http://hdl.handle.net/10447/91190.

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Mohamad, Mohamad Kheir. "Control System of Building using Modelling and Simulation." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-234236.

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Udržovaní vnitřních klimatických podmínek tak, aby byly v souladu s tepelným komfortem lidí, je klíčovou otázkou pro řízení systémů vytápění, větrání a klimatizace (HVAC systémy). Počítačové modelování nabízí virtuální prostředí pro simulaci vnitřních i vnějších podmínek a s jeho pomocí je možné navrhnout řešení pro řízení technických zařízení budov. Tento proces vyžaduje pochopení těchto prostředí z fyzikálního a matematického hlediska tak, aby bylo možné fyzikální procesy daných prostředí prezentovat pomocí vztahů a rovnic odrážejících jejích různé parametry. Simulační proces dále nabízí možnost popsat interakci mezi těmito modely a jejich chování v čase, dává výchozí reprezentace těchto prostředí, a umožňuje pochopení jejich chování před přenosem těchto modelů do reálných aplikací. Simulace umožnuje respektovat, a ovlivňovat jejích chování přes kontrolu navržených modelů. MATLAB/SIMULINK software má pokročilé schopnosti pro simulace systémů HVAC, a to vytvořením širokého pracovního prostředí pro designéry v závislosti na vývoji matematických modelů a jejích simulace pomocí SIMULINK, aby výsledky mohly být slučitelné s požadovanými výstupy. Tato dizertační práce se zaměřuje na proces modelování vnitřního prostředí v budovách, aby bylo možné pochopit chování klíčových parametrů, které mají vliv na tepelnou pohodu obyvatel či uživatelů, matematické modely vnitřního prostředí posluchárny byly navržené speciálně pro tři základní parametry: koncentrace oxidu uhličitého, teplota vzduchu a relativní vlhkost. Změny chování těchto parametrů v průběhu času jsou simulovány a poté strategie kontroly návrhu těchto parametrů může je udržet ve vhodných rozmezích komfortních pro obyvatele či uživatele, i když změny venkovního klimatu, tepelné a hmotnostní zatíží interiér. Pomocí matematických metod, některé optimalizační metody byly navrženy za účelem snížení spotřeby energie bez vlivu na mezní hodnoty těchto parametrů. Proces validace modelu se provádí porovnáním výsledků s reálnými výstupy monitoringu Honeywell Enterprise Buildings Integrator systémem (EBI) nainstalován v areálu univerzity.

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Charopkin, Aliaksandr. "Analýza a návrh marketingové komunikační strategie společnosti Phillip Morris na českém trhu." Master's thesis, Vysoká škola ekonomická v Praze, 2010. http://www.nusl.cz/ntk/nusl-82043.

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Thesis is dedicated to characteristics of marketing and communication mix, to analysis and evaluation of marketing and communication tools and processes of Czech branch of Philip Morris company and to possible advices. Thesis is divided into three parts. The first part is a theoretical one, dedicated to general marketing definitions. The second one deals with the specific of tobacco market and with extend and impacts of existing regulation. The last one describe the company this thesis is dedicated to, its tools and processes and also include the evaluation and some advices to improvement.

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FESCE, ELISA. "MATHEMATICAL MODELLING TO INVESTIGATE INFECTIOUS DISEASE DYNAMICS AND CONTROL STRATEGIES." Doctoral thesis, Università degli Studi di Milano, 2022. http://hdl.handle.net/2434/894476.

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Infectious diseases still represent one of the major threats for human health due to both their direct and indirect effects on public health and worldwide economies. Despite the current possibility to eradicate or control certain infections like smallpox, polio and measles, the increase in incidence of new infections (so called emerging diseases), or the increase in incidence or geographic range of ones that have existed previously (re-emerging diseases), poses a new threat to public health. To further complicate things, the role of animals in the insurgence and spread of new diseases is central. Of all emerging diseases indeed, the 60.3% originate by, or involve into their cycles, animals, and represent the so called zoonoses. The increase in number of emerging and re-emerging infections and their potential to fast spread into animal and human populations make central the development of tools to reduce human infection risk. Epidemiological studies become then central to understand the relationship among events, investigate their causal effects and understand risk factors. Despite of that, classical epidemiology, centred on the study of the relationships between events, show limits in the investigation of mechanisms underlying infection spread, and in considering the interactions among populations, thus possibly leading to simplistic and spurious conclusions. Mathematical modelling instead, and the development of a “dynamical epidemiology”, allows the investigation of dynamics of infections, thus providing us a mechanistic point of view to understand infection spread. The strengths of mathematical modelling applied to epidemiological studies are several. At first, they can investigate the extent to which an event can mechanistically influence another consequential event. This characteristic of mathematical modelling has a great application in public health, as it allows to prioritise interventions or studies on those events that have a major impact on disease outbreak. Another strength of mathematical modelling is its ability to describe the dynamics of an infectious disease by accounting for interactions among populations and sub-groups of populations within the same population. At least, mathematical modelling permits for theoretical investigations of mechanisms of transmission and to answer to “what if?” questions, allowing to explore theoretical scenarios which have not yet occurred or which needs to be preventively tested, like the application of an intervention strategy. With the present work we then provide four applications of mathematical modelling to infectious disease. We focused on two wildlife-originating infections: West Nile virus (WNV) and baylisascariasis. Both infections are emerging or re-emerging in Italy and can represent a threat for human beings due to their possible severe outcomes. Due to the potential harm they are for human beings, a thorough surveillance and a wide intervention and control plans are ongoing both to promptly identify the presence and circulation of their causative agents and to reduce human infection risk. A full understanding of WNV cycle is fundamental to reduce human infection risk, but several knowledge gaps still exist, especially on the role played by different bird species involved in its spread. For both infections moreover, despite several are the control strategies proposed a quantitative analysis of their performance has never been performed. Aimed at filling these gaps, we developed a mathematical model to simulate WNV spread, and used it to explore mechanisms driving infection spread. We found birds recovery rate and mosquito biting rate having the major influence on disease spread and thus being the most urgent mechanisms to be investigated via field and laboratory experiments. Birds’ susceptibility and their competence to infection have a negligible influence on disease spread, thus making investigations to understand them of secondary importance. These results might be of aid also in defining the characteristics of a bird species to be a good WNV spreader, by focusing the attention on species that have a small recovery rate or are frequently bitten by mosquitoes. Moreover, we found a negative effect of birds’ abundance in affecting WNV prevalence in mosquitoes, further helping us in distinguishing among species that are suitable to have a role in WNV spread. We then exploited the built model to explore intervention strategies against WNV. We showed that a reduction of the vector population is more effective than a reduction of birds’ abundance in an area. In particular, the best efficacy is shown by the reduction of mosquito breeding sites, followed by the active elimination of their eggs and larvae. On the contrary, reducing the abundance of competent birds or their reproductive sites can obtain an increase in human infection risk. Similarly, we also studied the effectiveness of different intervention strategies to reduce the number of Baylisascaris procyonis eggs in the environment. The ingestion of B. procyonis eggs indeed is the cause of baylisascariasis, an infection that can have severe health consequences in human beings. With our work we explore the effects both in terms of efficacy (i.e., potential to eliminate eggs from environment) and efficiency (i.e. the timing needed) of three different intervention strategies. The interventions tested are: the active culling of raccoons, raccoons’ anthelmintic treatment and faeces removal. We found that raccoon culling might have the best and faster results, highlighting the importance of assessing the intervention on the base of an objective prove on its efficacy. With the proposed work then, we highlighted the role of mathematical modelling in epidemiological studies, by, at first, exploiting their potential to investigate the extent to which an event can influence another consequential event. Secondly, we used them to describe the dynamics of an infectious disease, by accounting for interactions among populations, and focusing on mechanisms underlying infection spread. Moreover, we also exploited them for theoretical investigations, like the simulation of the application of an intervention strategy to reduce human infection risk is. In conclusion, mathematical modelling can widely help our understanding and management of infectious diseases through a new and different point of view from that provided by classical epidemiology. Mathematical modelling indeed includes the investigation of spreading mechanisms and non-linearity of interactions among individuals and subgroups of populations, thus allowing a more complete comprehension of diseases spread. The cooperation of diverse health professionals is fundamental to fully exploit both classical epidemiological studies and dynamics ones, and the effects of their cooperation can lead to a better knowledge of infections and a consequent reduction of human infection risk.

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13

Aguilera, Rayas Adolfo. "La competitivite des pmi : une demarche et des outils." Paris, ENSAM, 1987. http://www.theses.fr/1987ENAM0001.

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On passe en revue l'economie, la gestion, l'organisation et la gestion de la production, le theme principal de cette these etant cependant l'etude de la competitivite et son objectif, l'amelioration des performances des p. M. I. Cette etude a menee a clarifier certains concepts, a determiner les mecanismes de la competitivite, a elaborer une demarche et a proposer des outils

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14

Cangini, Marco. "Definizione delle strategie di attuazione per iniezione e accensione in un sistema di rapid control prototyping realizzato su piattaforma National Instruments." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3774/.

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15

Kos, Václav. "Návrh opatření pro rozvoj managementu firmy." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2009. http://www.nusl.cz/ntk/nusl-222155.

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This diploma work analyses the private building company KOS Consult Ltd., in the concrete the up to now way of making business, especially the function of company’s management. The particular economic analyses are utilized and on their base the new project for management development is worked up. This should lead both to the advancement of competitive strength and obtaining and consolidation of company’s position in the marketplace.

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16

Pokorný, Pavel. "Construction of the Optimal Control Strategy for an Electric-Powered Train." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-233935.

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Předložená disertační práce se zabývá popisem charakteru optimální strategie řízení pro elektrický vlak a výpočtem přepínacích okamžiků mezi jednotlivými optimálními jízdními režimy pro standardní typy odporové funkce. S využitím Pontrjaginova principu a souvisejících nástrojů teorie optimálního řízení odvodíme optimální strategii řízení a rovnice pro výpočet přepínacích okamžiků včetně odpovídajících rychlostních profilů. Kromě základního tvaru úlohy o energeticky optimální jízdě vlaku budeme uvažovat i její modifikace zahrnující globální rychlostní omezení, sklon trati i časově-energeticky optimální řízení vlaku. Navíc uvedeme i analýzu řešení s využitím teorie nelineární parametrické optimalizace. Důraz je kladen na exaktní tvar řešení s minimálním využitím numerických metod.

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17

Axengren, Josefine, and Sandra Petersson. "Att lyckas med strategisk planering och strategisk kontroll – En fallstudie på två svenska företag." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-10443.

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En konkurrenskraftig strategi kan vara en avgörande faktor för ett företags framgång. En formell företagsstrategi ser till att både de som deltar i den strategiska planeringen och i genomförandet följer samma mål. Det riktas kritik mot hur företag använder sig av strategisk planering och den största utmaningen för företagen ligger i att implementera strategin i verksamheten. Ett problem som är kopplat till strategier är att organisationers sätt att skapa konkurrensfördelar förändras snabbt. Företagen måste på grund av detta skapa förutsättningar för en ständigt pågående strategisk dialog.Syftet är att undersöka hur små och medelstora företag (SMF) arbetar med den strategiska planeringen i verksamheten och hur de kontrollerar att de strategiska aktiviteterna verkar i linje med det långsiktiga målet. Syftet med studien är även att ta reda på vilka faktorer som bidrar till en lyckad strategisk planering och implementering hos SMF. För att besvara vårt syfte har en multipel fallstudie gjorts på två SMF i Sjuhäradsområdet. Personliga intervjuer har genomförts med personer från företagens ledningsgrupp och styrelse.SMF har gemensamma karaktärsdrag gentemot stora företag och följande områden har undersökts: omgivningsfaktorer, organisationsmiljö och ledningen. Storleken på företaget har en betydande roll när det kommer till hur stor påverkan omgivningen har på ett företag. SMF har mer begränsade resurser vilket bidrar till större osäkerhet i omgivningen och att hålla koll på bland annat andra konkurrenter. Organisationsstrukturen hos SMF kännetecknas av en platt struktur med få ledningsnivåer vilket bidrar till en hög flexibilitet och förmåga att anpassa sig till marknaden. De få ledningsnivåerna bidrar till att antalet mellanchefer är färre och kravet på Vd:ns ledningsexpertis ökar.The Closed-Loop Management System är en modell som föreslås användas vid strategisk planering hos företag. Modellen består av fem steg: utveckla strategin, översätta strategin, planera handlingar, kontrollera och lär samt testa och anpassa strategin. Modellen beskriver hur företag ska gå tillväga från att formulera och uttala strategin till att implementera och kommunicera den i verksamheten och har använts som underlag för att undersöka hur SMFs arbetar med strategisk planering och strategisk kontroll i praktiken. För att säkerställa att implementering av strategin blivit lyckad behöver företagen utföra strategisk kontroll. Ett sätt att utföra strategisk kontroll är genom att använda sig av integrerad prestationsmätning. Det innebär en balanserad styrning mellan finansiella och icke-finansiella mått där orsak- och verkansamband mellan de olika måtten kartläggs och har undersökts på företagen i studien.Slutsatser som kan dras av studien är att tre viktiga faktorer som bidrar till strategisk framgång i SMF är: inställningen hos de anställda, val av organisationsstruktur och tydlig kommunikation. För att genomföra den strategiska planeringen används ett metodiskt arbetssätt för att strukturera upp aktiviteter och delmål som finns för att uppnå det övergripande målet. Genom att bryta ned det övergripande målet i delmål och aktiviteter säkerställer företagen att de kortsiktiga handlingarna verkar i linje med den långsiktiga strategiska planen. Det är även viktigt för företagen att kontrollera och mäta dessa aktiviteter. Finansiella och icke-finansiella mått används för strategisk kontroll men studiens resultat visar att de finansiella måtten är dominerande.
A competitive strategy is essential for a corporate’s success in their industry. The challenge is not only to design the strategy; it is to spread it throughout the organization. An integrated measurement system refers to support and control the activities and goals that leads to strategic success. Thus, earlier studies have shown that integrated measurement systems have contributed to improve large enterprises’ performances when applied in their businesses. However, this study refers to the gap of research on the use of integrated measurement systems and its impact on small and medium-sized enterprises (SME). This study focusses on two Swedish SMEs and research what characterize their qualities that contributes to strategic success. The study will also focus on how the SMEs apply strategic planning and strategic control in their business’s.The study was based on previous studies in the context of strategy. The interviews were conducted on two Swedish SMEs, and the respondents were people that are a part of each company’s management team that possess both knowledge and insight to the company’s strategic work.Our findings suggest that factors contributing to strategic success in SME’s are: the communication approach, the attitude of the employees and the organizational structure. The strategic planning in SME wasn’t based on a specific model to support the strategic planning. However, they use a similar methodical approach to implement the activities in the strategic planning process. Finally, the study also shows that SMEs use integrated measurement in terms of financial and non-financial measurements, where the financial measurements had a greater impact on the SME business’s.

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18

Agbi, Clarence. "Scalable and Robust Designs of Model - Based Control Strategies for Energy - Efficient Buildings." Research Showcase @ CMU, 2014. http://repository.cmu.edu/dissertations/333.

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In the wake of rising energy costs, there is a critical need for sustainable energy management of commercial and residential buildings. Buildings consume approximately 40% of total energy consumed in the US, and current methods to reduce this level of consumption include energy monitoring, smart sensing, and advanced integrated building control. However, the building industry has been slow to replace current PID and rule-based control strategies with more advanced strategies such as model-based building control. This is largely due to the additional cost of accurately modeling the dynamics of the building and the general uncertainty that model-based controllers can be reliably used in real conditions. The first half of this thesis addresses the challenge of constructing accurate grey-box building models for control using model identification. Current identification methods poorly estimate building model parameters because of the complexity of the building model structure, and fail to do so quickly because these methods are not scalable for large buildings. Therefore, we introduce the notion of parameter identifiability to determine those parameters in the building model that may not be accurately estimated and we use this information to strategically improve the identifiability of the building model. Finally, we present a decentralized identification scheme to reduce the computational effort and time needed to identify large buildings. The second half of this thesis discusses the challenge of using uncertain building models to reliably control building temperature. Under real conditions, building models may not match the dynamics of the building, which directly causes increased building energy consumption and poor thermal comfort. To reduce the impact of model uncertainty on building control, we pose the model-based building control problem as a robust control problem using well-known H1 control methods. Furthermore, we introduce a tuning law to reduce the conservativeness of a robust building control strategy in the presence of high model uncertainty, both in a centralized and decentralized building control framework.

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19

Pikman, Oxana. "Komparace vývoje ekonomického chování v Rusku, v Kazachstánu a na Ukrajině." Master's thesis, Vysoká škola ekonomická v Praze, 2012. http://www.nusl.cz/ntk/nusl-162788.

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Master thesis was focused on comparative analysis of economic behavior on chosen population of Russia, Ukraine and Kazakhstan. The main goal of this thesis was to define basic trends of the economic behavior in the different dimensions such as history, politics, economics, law and psychology. In the beginning of the thesis was set up hypothesis concerning main factors contributed to the related topic: adaptation, control, trust and fear. Analytical part was focused on research of relationship between defined factors and the process of choosing economic behavior strategy.

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20

Axelsson, Johanna, and Sarah Bernelind. "Elevator Control Strategies." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-134900.

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The purpose of this essay is to investigate if it is eective to switch strategies for elevators during one day in an oce building. This essay describes some of the strategies in use today, followed by a comparison and analysis of two of the strategies described. We have also implemented optimizations to one of these strategies. From our test results we can conclude that our optimized strategy worked and produced better results on average waiting time and total traveling time than the two strategies we previously implemented and that it is not necessarily eective to completely change strategies but change parts of them depending on the trac ow.
Syftet med denna rapport ar att undersoka om det ar eektivt att byta strategi for hissar i en kontorsbyggnad under en dags olika trakoden. Forst beskrivs nagra av de vanligaste strategierna, vilket foljs av en jamforelse och analys av tva av dessa. For att kunna jamfora dessa strategier har en implementation av ett program som simulerar en byggnad med hissar gjorts. I programmet anvands sedan dessa strategier for att ta fram testresultat. Den mest eektiva av dessa tva strategier har optimerats och jamforts ytterligare med de tidigare resultaten. Testresultaten visar att den optimerade strategin var den mest eektiva med avseende pa genomsnittsvantetiden och den totala genomsnittsrestiden, och att det inte ar nodvandigt att helt byta strategi under dagen, men att det lonar sig att optimera delar av den, beroende pa trakodet

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21

Ceder, Frederick, and Alexandra Nordin. "Elevator Control Strategies." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-134902.

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This paper investigates the efficiency of known elevator control strategies by simulating these in an own made apartment simulator. Efficiency will be determined by the lowest product of the energy consumption (Watt/second), average waiting time, average transfer time and the maximum waiting time of a passenger, which is the output by the simulator. The apartment simulator will simulate the elevator behavior, according to a respective control strategy, and the passenger flow on each respective floor in a specific test scenario. In this test scenario, passengers always travel either to the ground floor or to their respective home floor to simulate an apartment complex on a workday. The outcome of the investigation was that a control strategy that would prioritize elevator orders, i.e. calls made from inside the elevator, remember calls and collect passengers that are on route was the most efficient, both in terms of low energy consumption and passenger satisfaction (low transit and waiting times).

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22

Johnson, Mackie. "Retail Inventory Control Strategies." ScholarWorks, 2016. https://scholarworks.waldenu.edu/dissertations/3171.

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Despite using computerized merchandise control systems in retail, the rate of stockouts has remained stagnant. The inability to satisfy customer needs has caused a loss of 4% in potential revenue and resulted in dissatisfied customers. The purpose of this qualitative multiple case study was to explore cost-effective inventory control strategies used by discount retail managers. The conceptual framework that grounded the study was chaos theory, which helped identify why some business leaders rely on forecasting techniques or other cost-effective strategies as an attempt to prevent stockouts. The target population was comprised of discount retail managers located throughout northeast Jacksonville, Florida. Purposeful sampling led to selecting 6 retail managers who successfully demonstrated cost-effective inventory control strategies for mitigating stockouts. Data were collected through face-to-face semistructured interviews, company websites, and company documents. Analysis included using nodes to identify similar words and axial-coding to categorize the nodes into themes. Transcript evaluation, member checking, and methodological triangulation strengthened the credibility of the findings. Five themes emerged: (a) internal stockout reduction strategies, (b) external stockout reduction strategies, (c) replenishment system strategies, (d) inventory optimization strategies, and (e) best practices for inventory control. This study may contribute to positive social change by improving inventory management, which may reduce demand fluctuations in the supply chain and reduce logistics costs in the transportation of freight thereby leading to improved customer satisfaction.

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23

Dušek, Jiří. "Řízení stroje s PM v d-q osách při použití Matlab/Simulink." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218789.

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Tato práce se zabývá synchronním motorem s permanentními magnety na rotoru (PMSM), jeho modelováním a návrhu regulační struktury. V práci jsou uvedeny způsoby a výhody použití permanentních magnetů v elektrických motorech. Dále se práce zabývá transformací třífázové soustavy do dq0. Pomocí Parkovy transformace jsou v práci odvozeny rovnice stroje v dq0 souřadnicovém systému a vytvořeny náhradní schémata stroje v dq osách. Rovnice i schémata zahrnují jak ztráty v mědi, tak ztráty v železe. Náhradní schémata jsou popsány elektrickými a mechanickými rovnicemi a následně překresleny do grafické podoby v programu Matlab Simulink. Vytvořeny jsou dva modely PMSM, jeden s uvažováním ztrát v železe a druhý bez těchto ztrát. Pro oba dva modely je zde popsán postup návrhu regulátorů proudu a otáček. Pro model, u kterého jsou uvažovány ztráty v železe je navíc použito více druhů řídicích strategií a tyto strategie jsou mezi sebou navzájem porovnány.

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24

Alimohammadi, Reza. "Portfolio strategic control and portfolio management performance." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/102162/4/Reza_Alimohammadi_Thesis.pdf.

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This thesis presents the development of a new control mechanism for managing portfolio of projects in today’s rapidly changing environment and fierce global competitions. “Portfolio Strategic Control” combines elements of portfolio management and functions of strategic management to control portfolios in a strategic manner and improve portfolio’s performance. This feedforward approach can be applied in parallel with traditional feedback control system to prepare portfolio for future environments by aligning its objectives with organisational strategy, managing resources, risks, and opportunities in an integrated fashion, and adding elements of flexibility and learning to portfolio.

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Chow, Andy Ho Fai. "Adaptive traffic control system : a study of strategies, computational speed and effect of prediction error /." View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202002%20CHOW.

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Анотація:

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002.
Includes bibliographical references (leaves 126-129). Also available in electronic version. Access restricted to campus users.

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26

Kahriman, Edin, and Srdjan Jovanovic. "Alternative Strategies for Engine Control." Thesis, Linköpings universitet, Reglerteknik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119470.

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The existing powertrain control system in Volvo CE's vehicles consists of various types of physical quantities that are controlled. One of them is the engine speed. The purpose of this thesis is to investigate whether there are other control strategies suitable for engine speed control, than the existing one. Currently, the existing control system requires re-calibration of the control parameters if hardware in the vehicle is replaced. The current controller is a gain-scheduled PID controller with control parameters that varies over the operating range. The aim has been to develop several different adaptive control strategies. Adaptive control methods are expected to adapt to the changes of the system that a replacement of hardware can bring. The performance and robustness of the developed controllers have been compared with the existing controller. The approach has been to implement the control strategies in Matlab/Simulink and simulate the process with existing engine software provided by Volvo CE. The next step was to test and verify the controllers in a real machine. The focus in this thesis work has been on the adaptive control strategies MRAC (Model-Reference Adaptive Control) and L1 Adaptive Control. In the MRAC structure the desired performance is specified in terms of a reference model that the real system is supposed to follow. Each time an error is generated, by comparing actual and desired output, a suitable algorithm is used in order to obtain the control signal that can minimize the error. In addition, modeling errors and disturbances are estimated so that the controller can compensate for these. L1 Adaptive Control is an extension of the MRAC structure. The difference is that before the control signal is fed to the real system, it is low-pass filtered. This is done in order to prevent feeding high frequencies into the system. The results show that adaptive control has potential to be used in engine speed control. Reference following and disturbance rejection is well handled and simulations have furthermore shown that the developed controllers can deal with changes in the hardware. One of the developed L1-controllers was implemented in a real machine with promising results.
Det existerande styrsystemet i Volvo CE:s maskiner har till uppgift att styra och reglera flera olika fysikaliska storheter. En av dessa storheter är motorvarvtalet. Syftet med detta examensarbete är att undersöka alternativa reglerstrategier som kan användas för att styra motorvarvtalet. Problemet idag är att det nuvarande styrsystemet kräver omkalibrering av regulatorparametrar när befintlig hårdvara i maskinen behöver ersättas på grund av föråldring eller slitage. Den nuvarande regulatorn är en parameterstyrd PID-regulator där regulatorparametrarna beror av aktuell arbetspunkt. Målet har varit att utveckla och prova flera olika adaptiva reglerstrategier. Dessa metoder förväntas kunna hantera förändringar och adaptera sig mot nya förhållanden och omständigheter som en hårdvaruförändring kan medföra. Prestanda och robusthet som de utvecklade regulatorerna erhåller har jämförts mot den existerande regulatorstrukturen. Tillvägagångssättet har varit att implementera reglerstrategierna i Matlab/Simulink samt simulera med tillhörande motormjukvara som Volvo CE tillhandahållit. I nästa fas skulle regulatorerna testas och verifieras i en riktig maskin. Fokuset har under detta examensarbete riktats mot de två adaptiva reglerstrategierna Model-Reference Adaptive Control (MRAC) och L1 Adaptive Control. MRAC-strukturen bygger på att specificera prestandan genom en referens-modell som det riktiga systemet skall följa. Varje gång en avvikelse uppstår så beräknas en lämplig styrsignal genom att beakta och försöka minimera skillnaden mellan det riktiga systemet och den önskade referens-modellen. Till detta modelleras och skattas störningar som regulatorn skall kompensera för. Tekniken inom L1 Adaptive Control är en utvidgning av MRAC. Önskat beteende specificeras även för denna regulatorstruktur men största skillnaden är att innan styrsignalen matas in till systemet så lågpassfiltreras den. Detta görs i förebyggande syfte för att inte släppa in onödigt höga frekvenser in i systemet. Resultaten visar att adaptiv reglering av motorvarvtalet har potential. Referensföljning och undertryckning av störningar hanteras väl och simuleringar har dessutom visat att de utvecklade regulatorerna kan hantera hårdvaruändringar. En av de utvecklade L1-regulatorerna implementerades i en riktig maskin och resultaten såg lovande ut.

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Ng, Kwai Choi Stanley. "Regulation strategies for process control." Thesis, University of Sunderland, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337287.

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28

Goel, Anukul. "Control strategies for supercavitating vehicles." [Gainesville, Fla.] : University of Florida, 2002. http://purl.fcla.edu/fcla/etd/UFE0000537.

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29

Haviland, Jesse. "Control strategies for reactive manipulation." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/236551/1/Jesse%2BHaviland%2BThesis%282%29.pdf.

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For a robot to operate in the real world, which is dynamic, unstructured, and unknowable, it must be able to react and adapt to the ever-changing state of the robot, environment, and goal. This thesis develops novel reactive motion controllers, which, unlike prior approaches, can rapidly, robustly and safely operate in real-world environments. The thesis also provides extensive software and educational materials to encourage the adoption and ongoing development of this new reactive robot motion paradigm.

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30

Luu, Ngoc An. "Control and management strategies for a microgrid." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENT075/document.

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Aujourd'hui et à l'avenir, l'augmentation des prix du carburant, la déréglementation et les contraintes de l'environnement donnent plus de possibilités pour l'utilisation des sources d'énergie renouvelables (SER) dans les réseaux électriques. Un concept de microgrid est nécessaire afin d'intégrer les sources d'énergie renouvelables dans le réseau électrique. Ce microgrid comprend un réseau de basse tension (BT) avec les ressources d'énergie distribuées (DER) ainsi que les moyens de stockage et des charges flexibles. L'intégration des énergies renouvelables dans un microgrid peut causer des enjeux et des impacts sur le fonctionnement du microgrid. C'est pourquoi dans cette thèse, un dimensionnement optimal et les stratégies de fonctionnement en sécurité, fiabilité et efficacité d'un microgrid comportant des productions photovoltaïques (PV), des systèmes de stockage d'énergie de la batterie (BESS) et / ou les diesels sont proposés. Tout d'abord, la technique d'optimisation itérative est utilisée pour trouver le dimensionnement optimal d'un microgrid. Deuxièmement, les stratégies de contrôle de tension et de fréquence pour un microgrid en mode îloté en utilisant les statismes sont étudiées. De plus, nous proposons les stratégies intelligentes de contrôle de tension et de la fréquence à l'aide de la logique floue. De cette manière, la fréquence est exprimée non seulement en fonction de la puissance active, mais aussi de l'état de charge de BESS et des régimes de fonctionnement de microgrid. Et enfin, une méthode pour optimiser la gestion de l'énergie dans l'exploitation d'un microgrid est proposée dans cette thèse. La programmation dynamique est utilisée pour trouver le minimum du coût du carburant compte tenu des émissions par la planification des ressources énergétiques distribuées (de DER) dans un microgrid en mode îloté ainsi que pour minimiser le coût d'énergie et les puissances d'échange avec le réseau en mode connecté. Les résultats de simulation obtenus montrent la précision et l'efficacité des solutions proposées
Today and in the future, the increase of fuel price, deregulation and environment constraints give more opportunities for the usage of the renewable energy sources (RES) in power systems. A microgrid concept is needed in order to integrate the renewable sources in the electrical grid. It comprises low voltage (LV) system with distributed energy resources (DERs) together with storage devices and flexible loads. The integration of RES into a microgrid can cause challenges and impacts on microgrid operation. Thus, in this thesis, an optimal sizing and security, reliability and economic efficiency operation strategies of a microgrid including photovoltaic productions (PV), battery energy storage systems (BESS) and/or diesels is proposed. Firstly, the iterative optimization technique is used to find the optimal sizing of a microgrid. Secondly, the voltage and frequency control strategies for an island microgrid by using droop control methods are studied. Furthermore, we propose intelligent voltage and frequency control strategies by using fuzzy logic. By this way, the frequency is expressed not only as the function of active power but also the state of charge of BESS and the operation states of microgrid. And finally, a method to optimize the energy management in operation of a microgrid is proposed in this thesis. Dynamic programming is used to find the minimum the cost of fuel considering the emissions by scheduling of distributed energy resources (DERs) in an island microgrid as well as to minimize the cash flows and the exchanged power with the main grid in a grid-connected mode. The simulation results obtained show the accuracy and efficiency of the proposed solutions

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Kasburg, Cristiane Regina. "Seleção e caracterização de isolados de fungos entomopatogênicos visando ao controle do ácaro vermelho Dermanyssus gallinae (Acari: Dermanyssidae)." Universidade Estadual do Oeste do Parana, 2016. http://tede.unioeste.br:8080/tede/handle/tede/711.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Brazil is one of the largest producers of eggs, and this production is constantly growing, based on investment independent producers and the creation of cooperatives. Brazilian poultry facilities are mainly in wood with metal cages. There are few fully automated poultry, mainly by the high initial investment they require. The wooden structures, usually older, favor the appearance of some arthropod pests, as the poultry red mite Dermanyssus gallinae (De Geer, 1778) (Acari: Dermanyssidae). This mite is hematophagous and features gregarious and nocturnal behavior, spending the day hiding in cracks and crevices of the poultry houses, timber slots, dirt and debris accumulation of food and cobwebs. Among the damage caused by this mite infestation highlights the stress of birds, dermatitis and anemia, which can cause a decrease in production. Moreover, D. gallinae can also be transmitter the bacteria genus Salmonella, viruses of Newcastle disease and avian pox. Control strategies are mainly based on the use of chemical acaricides, which present risks to animals, poultry farmers and eggs consumers by residues in the eggs. Also, can select populations of resistant mites. Currently, the integrated management with use of less impactful strategies has been researched aiming their use at the field level. Among these strategies include the use of extracts and essential oils, inert powders (diatomaceous earth, silicas, talc), predators and entomopathogenic fungi. The entomopathogenic fungus has emerged as one of the most efficient techniques to control D. gallinae in laboratory conditions, but with a few field studies. The combination of these control strategies are also being studied aiming to find a method that is efficient and at the same time represents no risk to human and animal health.
O Brasil está entre os maiores produtores mundiais de ovos, sendo esta produção em constante crescimento, impulsionada principalmente por investimento de produtores independentes e da criação de cooperativas. As instalações aviárias brasileiras são principalmente em madeira com gaiolas metálicas. Há poucos aviários completamente automatizados, principalmente pelo alto investimento inicial que estes exigem. As estruturas em madeira, geralmente mais antigas, favorecem o aparecimento de alguns artrópodes-pragas, dentre os quais destaca-se o ácaro vermelho das galinhas Dermanyssus gallinae (De Geer, 1778) (Acari: Dermanyssidae). Este ácaro é hematófago e apresenta comportamento gregário e hábitos noturnos, passando o dia escondido em frestas e fendas dos aviários, ranhuras da madeira, restos de sujeira e acúmulo de comida e teias de aranha. Dentre os prejuízos causados pelas infestações deste ácaro, destacam-se o estresse das aves, a dermatite e a anemia, a qual pode ocasionar diminuição da produção. Além disso, D. gallinae também pode ser transmissor de bactérias do gênero Salmonella, vírus causadores da doença de Newcastle e da varíola aviária. As estratégias de controle são baseadas principalmente no uso de acaricidas químicos, os quais representam riscos aos animais, aos avicultores, aos consumidores pelos resíduos que podem deixar nos ovos, além de selecionar populações de ácaros resistentes. Atualmente, o manejo integrado com utilização de estratégias menos impactantes está sendo pesquisado, visando sua utilização no controle da praga. Dentre estas estratégias, destacam-se os extratos e óleos essenciais vegetais, pós inertes (terra de diatomáceas, sílicas, talcos), predadores e fungos entomopatogênicos. Os fungos entomopatogênicos têm se apresentado como uma das técnicas mais eficientes para controle de D. gallinae em condições de laboratório, porém com poucos estudos de campo. A combinação destas estratégias de controle também estão sendo pesquisadas visando encontrar um método que seja eficiente e ao mesmo tempo não represente riscos a saúde animal e humana.

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Damke, Joice Franciele Wendling. "Sistemas de controle estratégico e contratos psicológicos: um estudo na Fundação Parque Tecnológico Itaipu – Brasil." Universidade Estadual do Oeste do Paraná, 2017. http://tede.unioeste.br/handle/tede/3596.

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An increasing number of studies have sought to analyze the relationship between managerial systems control and psychological contracts. There are few studies that evaluate this relationship through the strategic levers of control proposed by Simons (1995). Combining variables in these dimensions, this study aimed to investigate the relationship between strategic systems control and psychological contracts at Itaipu Technological Park Foundation - Brazil. Data collected from a survey of 197 respondents using Simon´s model (1995) as a construct for strategic systems control and by Rousseau (1989, 1995) for psychological contracts and investigated by correlation analyzes revealed positive associations between strategic levers of control and psychological contracts, highlighting the levers of diagnostic and interactive systems, which produced the highest correlations with psychological contracts in the research organization. The results show the relationship of strategic control levers' interdependence in the development of psychological contracts and point to gaps (discrepancies) between expected and performed in terms of the formal use of control systems, one of the managerial contributions of this study
Um número crescente de estudos tem buscado analisar a relação entre sistemas de controles gerenciais e contratos psicológicos. São raros os estudos que avaliam esta relação por meio das alavancas de controle estratégico propostos por Simon (1995). Conjugando variáveis nessas dimensões, este estudo objetivou investigar a relação entre sistemas de controle estratégico e contratos psicológicos na Fundação Parque Tecnológico Itaipu Brasil. Dados levantados em survey junto a 197 respondentes utilizando o modelo de Simon (1995) como constructo para sistemas de controle estratégico, de Rousseau (1989; 1995) para contratos psicológicos, e investigados por análises de correlações, revelaram associações positivas entre as alavancas de controle estratégico e contratos psicológicos, com destaque para as alavancas dos sistemas diagnósticos e interativos, que produziram as maiores correlações com contratos psicológicos na organização pesquisada. Os resultados evidenciam a relação de interdependência das alavancas de controle estratégico no desenvolvimento de contratos psicológicos e apontam os gaps (discrepâncias) entre o esperado e o desempenhado em termos da utilização formal dos sistemas de controle, uma das contribuições de natureza gerencial deste estudo.

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Munoz, Carpintero Diego Alejandro. "Strategies in robust and stochastic model predictive control." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:2f6bce71-f91f-4d5a-998f-295eff5b089a.

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The presence of uncertainty in model predictive control (MPC) has been accounted for using two types of approaches: robust MPC (RMPC) and stochastic MPC (SMPC). Ideal RMPC and SMPC formulations consider closed-loop optimal control problems whose exact solution, via dynamic programming, is intractable for most systems. Much effort then has been devoted to find good compromises between the degree of optimality and computational tractability. This thesis expands on this effort and presents robust and stochastic MPC strategies with reduced online computational requirements where the conservativeness incurred is made as small as conveniently possible. Two RMPC strategies are proposed for linear systems under additive uncertainty. They are based on a recently proposed approach which uses a triangular prediction structure and a non-linear control policy. One strategy considers a transference of part of the computation of the control policy to an offline stage. The other strategy considers a modification of the prediction structure so that it has a striped structure and the disturbance compensation extends throughout an infinite horizon. An RMPC strategy for linear systems with additive and multiplicative uncertainty is also presented. It considers polytopic dynamics that are designed so as to maximize the volume of an invariant ellipsoid, and are used in a dual-mode prediction scheme where constraint satisfaction is ensured by an approach based on a variation of Farkas' Lemma. Finally, two SMPC strategies for linear systems with additive uncertainty are presented, which use an affine-in-the-disturbances control policy with a striped structure. One strategy considers an offline sequential design of the gains of the control policy, while these are variables in the online optimization in the other. Control theoretic properties, such as recursive feasibility and stability, are studied for all the proposed strategies. Numerical comparisons show that the proposed algorithms can provide a convenient compromise in terms of computational demands and control authority.

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34

Laws, Christopher Neil. "Dynamic routing in queueing networks." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385435.

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35

Sethuraman, Shanthi. "Variable sampling interval control strategies for a process control problem." Diss., Virginia Tech, 1995. http://hdl.handle.net/10919/40313.

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36

Skelton, Claude Eugene II. "Mixed Control Moment Gyro and Momentum Wheel Attitude Control Strategies." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/9677.

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Attitude control laws that use control moment gyros (CMGs) and momentum wheels are derived with nonlinear techniques. The control laws command the CMGs to provide rapid angular acceleration and the momentum wheels to reject tracking and initial condition errors. Numerical simulations of derived control laws are compared. A trend analysis is performed to examine the benefits of the derived controllers. We describe the design of a CMG built using commercial off-the-shelf (COTS) equipment. A mixed attitude control strategy is implemented on the spacecraft simulator at Virginia Tech.
Master of Science

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37

Sabattini, Lorenzo <1983&gt. "Nonlinear Control Strategies for Cooperative Control of Multi-Robot Systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4465/1/sabattini_lorenzo_tesi.pdf.

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This thesis deals with distributed control strategies for cooperative control of multi-robot systems. Specifically, distributed coordination strategies are presented for groups of mobile robots. The formation control problem is initially solved exploiting artificial potential fields. The purpose of the presented formation control algorithm is to drive a group of mobile robots to create a completely arbitrarily shaped formation. Robots are initially controlled to create a regular polygon formation. A bijective coordinate transformation is then exploited to extend the scope of this strategy, to obtain arbitrarily shaped formations. For this purpose, artificial potential fields are specifically designed, and robots are driven to follow their negative gradient. Artificial potential fields are then subsequently exploited to solve the coordinated path tracking problem, thus making the robots autonomously spread along predefined paths, and move along them in a coordinated way. Formation control problem is then solved exploiting a consensus based approach. Specifically, weighted graphs are used both to define the desired formation, and to implement collision avoidance. As expected for consensus based algorithms, this control strategy is experimentally shown to be robust to the presence of communication delays. The global connectivity maintenance issue is then considered. Specifically, an estimation procedure is introduced to allow each agent to compute its own estimate of the algebraic connectivity of the communication graph, in a distributed manner. This estimate is then exploited to develop a gradient based control strategy that ensures that the communication graph remains connected, as the system evolves. The proposed control strategy is developed initially for single-integrator kinematic agents, and is then extended to Lagrangian dynamical systems.

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Sabattini, Lorenzo <1983&gt. "Nonlinear Control Strategies for Cooperative Control of Multi-Robot Systems." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4465/.

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This thesis deals with distributed control strategies for cooperative control of multi-robot systems. Specifically, distributed coordination strategies are presented for groups of mobile robots. The formation control problem is initially solved exploiting artificial potential fields. The purpose of the presented formation control algorithm is to drive a group of mobile robots to create a completely arbitrarily shaped formation. Robots are initially controlled to create a regular polygon formation. A bijective coordinate transformation is then exploited to extend the scope of this strategy, to obtain arbitrarily shaped formations. For this purpose, artificial potential fields are specifically designed, and robots are driven to follow their negative gradient. Artificial potential fields are then subsequently exploited to solve the coordinated path tracking problem, thus making the robots autonomously spread along predefined paths, and move along them in a coordinated way. Formation control problem is then solved exploiting a consensus based approach. Specifically, weighted graphs are used both to define the desired formation, and to implement collision avoidance. As expected for consensus based algorithms, this control strategy is experimentally shown to be robust to the presence of communication delays. The global connectivity maintenance issue is then considered. Specifically, an estimation procedure is introduced to allow each agent to compute its own estimate of the algebraic connectivity of the communication graph, in a distributed manner. This estimate is then exploited to develop a gradient based control strategy that ensures that the communication graph remains connected, as the system evolves. The proposed control strategy is developed initially for single-integrator kinematic agents, and is then extended to Lagrangian dynamical systems.

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39

Ibrahim, Khan M. "Tuberculosis in Pakistan improving control strategies /." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=969899300.

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40

Kørte, Steffen Østensjø. "Guidance & Control Strategies for UUVs." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for marin teknikk, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-16228.

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Focus on safety and effectiveness in the oil and gas industry has increased the need for advanced control system for underwater vehicles. For remotely operated vehicles (ROVs) effectiveness when conducting deep sea operation is extremely critical both concerning safety and cost. For AUVs conducting survey missions, energy and collision avoidance are critical factors. A control system for ROV Minerva is being developed through the AUR-Lab at the Institute of Marine Technology at NTNU. Several guidance features have been investigated, with respect to different mission the ROV should be able to do. A guidance system has been developed, where basic functions such as a DP system with station keeping and trajectory tracking was the focus of the project thesis of the author. More advanced functionality with respect to path following has been developed, where focus have been set on different strategies to apply when the ROV is following a path. Simulations based on different strategies for following a lawnmower pattern have been simulated and evaluated with respect to time, energy and control objective. Full scale experiments with the ROV Minerva show that especially the forward speed versus arc radius is an important issue. The results show that the ROV is able to follow a path made out of straight lines and circular arcs, and particularly lawnmower patterns. For an underwater vehicle to be able to operate autonomously, stationary and dynamic obstacles have to be taken into account. A collision avoidance system based on local collision avoidance algorithms has been implemented, where focus has been on reactivity with respect to unmapped obstacles. The collision avoidance system has been through initial full scale tests with ROV Minerva, and the result are promising.

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41

Al-Mudhaffar, Azhar. "Impacts of Traffic Signal Control Strategies." Doctoral thesis, Stockholm : Division of transports and logistics, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4268.

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42

Zolotas, Argyrios C. "Advanced control strategies for tilting trains." Thesis, Loughborough University, 2002. https://dspace.lboro.ac.uk/2134/4279.

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The use of tilting bodies on railway vehicles is becoming increasingly widespread: a number of well-established services using tilt technology already exist around the world, and will appear again in the UK over the next year or so. The motivation for tilting railway vehicles is that they give a cost-effective means of achieving a substantial reduction in journey time by increasing the vehicle speed during curves. Early tilt controller designs were based upon local vehicle measurements, however at that time this approach did not prove very successful. Nowadays most European manufacturers use the so called ‘precedence' control scheme, utilising measurements from precedent vehicles to achieve ‘precedence' information. However, achieving a satisfactory local tilt control strategy is still an important research target because of the system simplifications and more straightforward failure detection. The thesis describes a comprehensive study of tilt control, and its aim is to employ advanced control techniques - based upon practical sensors - with the particular objective of identifying effective strategies which can be applied to each vehicle independently, i.e. without using precedence control. The sensors employed for control design are in particular mounted on the vehicle passenger coach. Most of the work has been undertaken using Matlab, and this has included a proper assessment of the ride quality issues.

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Chacón, Vásquez Mercedes. "Strategies for wireless networked control systems." Thesis, University of Strathclyde, 2017. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=28771.

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Networked Control Systems (NCS) and Wireless Networked Control Systems (WNCS) are control systems where controllers, sensors and final elements of control are connected to a mutual communication network. The inclusion of the network introduces delays and dropouts, which greatly influence the stability and robustness of the controller. While there is wealth in theoretical contributions to NCS, it is still imperative to study more applications and investigate the effects of networks in a real-time operation. There are also open problems that require further study of the impact of disturbances, constraints and strong interactions in complex NCS. This thesis is concerned with the design of control strategies for WNCS mainly focused on Model-Based Predictive Control (MBPC), Proportional Integral Derivative (PID) and decentralised schemes with the aim of creating control laws suitable for compensating time-varying delays and dropouts. These strategies rely on optimisation problems which incorporate robustness and performance restrictions to compute the optimum controller. The performance and robustness of the controllers are evaluated through extensive experiments in a network simulator. A new adaptive Internal Model Control (IMC) controller has been developed to adapt to the network requirements and compute the IMC model parameters online. A new robust PID for NCS under random delays has been created by solving a new constrained optimisation problem that included constraints of maximum sensitivity to guarantee robustness. A novel optimal immune PID is developed to improve the performance of NCS under time-varying delays and dropouts. Simulation results show that the controller offers greater flexibility and improves the performance and robustness with respect to the other methods studied. Four more controllers have been tested and extensive tests have indicated stability for a limited percentage of process model variations and dropouts. Predictive PID controllers, with similar properties to MBPC, are developed to compensate dropouts in WNCS. A quadratic programming problem optimises a new MBPC cost function to find the optimal PID gains. The approach successfully maximises the performance by changing the controller gains at every sampling time and allowing maximum variations of system parameters and dropouts. Also, a new constrained predictive PID controller is presented to deal with input saturation. Simulation results show the superiority of the design in comparison with the control schemes studied earlier. Furthermore, a decentralised wireless networked model predictive control design for complex industrial systems has been developed. Also, the method has been applied to wind farm control. The proposed decentralised control offers an effective and innovative solution to improve the performance of large industrial applications.

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Chen, Xin 1973. "Coordinating inventory control and pricing strategies." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/29598.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2003.
Includes bibliographical references (p. 127-130).
Traditional inventory models focus on effective replenishment strategies and typically assume that a commodity's price is exogenously determined. In recent years, however, a number of industries have used innovative pricing strategies to manage their inventory effectively. These developments call for models that integrate inventory control and pricing strategies. Such models are clearly important not only in the retail industry, where price-dependent demand plays an important role, but also in manufacturing environments in which production/distribution decisions can be complemented with pricing strategies to improve the firm's bottom line. To date, the literature has confined itself mainly to models with variable ordering costs but no fixed costs. Extending some of these models to include a fixed cost component is the main focus of this thesis. In this thesis, we start by analyzing a single product, periodic review joint inventory control and pricing model, and characterizing the structure of the optimal policy under various conditions. Specifically, for the finite horizon periodic review case, we show, by employing the classical k-convexity concept, that a simple policy, called (s, S, p), is optimal when the demand functions are additive. For the model with more general demand functions, we show that an (s, S, p) policy is not necessarily optimal. We introduce a new concept, the symmetric k-convex functions, and apply it to provide a characterization of the optimal policy. Surprisingly, in the infinite horizon periodic review case, the concept of symmetric k-convex functions allows us to show that a stationary (s, S, p) policy is optimal for both discounted and average profit models even for general demand functions.
(cont.) Our approach developed for the infinite horizon periodic review joint inventory control and pricing problem is then extended to a corresponding continuous review model. In this case, we prove that a stationary (s, S, p) policy is optimal under fairly general assumptions. Finally, the symmetric k-convexity concept developed in this thesis is employed to characterize the optimal policy for the stochastic cash balance problem.
by Xin Chen.
Ph.D.

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45

Abuzeid, Mustafa R. "Advanced braking control strategies for trains." Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/32027.

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The thesis describes modelling methods that are being developed to support the design and evaluation of intelligent railway braking control systems. A particular feature is that the models include higher order vehicle and train dynamics, the effects of which are expected to become important as the performance of braking systems improve. The thesis describes mathematical techniques for modelling braking systems starting with braking of a single wheelset on its own, then a single braked wheelset in a bogie, followed by a single braked wheelset in a complete vehicle and finally four wheelsets braked in a complete vehicle. The mathematical model for the braking system combines the non-linear creep laws governing the braking forces generated between wheel and rail with the suspension dynamics of a typical high speed railway vehicle.

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46

Weidman, Justin Earl. "Dust Control Usage: Strategic Technology Interventions." Diss., Virginia Tech, 2012. http://hdl.handle.net/10919/26562.

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An intervention to improve adoption of dust control technology is designed, implemented and evaluated using three theoretical frameworks: the Health Belief Model (HBM), Diffusion of Innovation, and the Technology Acceptance Model. A quasi-experimental design (pretest-posttest, with control group) was used to evaluate the effectiveness of the intervention. An integrated conceptual model, employing key constructs from these frameworks, was developed to predict and describe â adoption readinessâ . Adoption readiness combines the attitudes and perceptions about a technology with the capacity to implement the technology. The primary hypothesis was that the key construct scores of the three theoretical models would improve post-intervention, particularly, â adoption readinessâ . Workers in the drywall finishing industry have been found to be at risk of developing respiratory disease and disability. Studies have shown that drywall finish workers have been subject to overexposure to dust concentrations that contain respiratory heath hazardous particles including silica, talc, mica, and calcite. Prevention through Design (PtD) solutions, which are effective at reducing dust levels, do exist for these operations. Some of these PtD solutions include using vacuum sanders, wet sanding methods, pole sanding and using low dust joint compound in lieu of using personal protective equipment (PPE) as a primary form of exposure protection. Previous studies have determined barriers to adoption of current PtD solutions for dust exposure reduction. Usability, productivity, quality of finish and cost were all identified as barriers to adoption. An intervention directed at those involved in the drywall industry is needed to increase the usage of engineered dust control. This dissertation project developed, implemented, and evaluated three interventions to address the barriers to adoption through education and marketing strategies. Development of the interventions included strategies to improve industry usage of dust control technologies. The interventions targeted workers, small companies, and large companies involved in drywall finishing.
Ph. D.

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47

Round, Philip A. "Simulation of robot manipulator control strategies." Thesis, Aston University, 1988. http://publications.aston.ac.uk/11918/.

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The high capital cost of robots prohibit their economic application. One method of making their application more economic is to increase their operating speed. This can be done in a number of ways e.g. redesign of robot geometry, improving actuators and improving control system design. In this thesis the control system design is considered. It is identified in the literature review that two aspects in relation to robot control system design have not been addressed in any great detail by previous researchers. These are: how significant are the coupling terms in the dynamic equations of the robot and what is the effect of the coupling terms on the performance of a number of typical independent axis control schemes?. The work in this thesis addresses these two questions in detail. A program was designed to automatically calculate the path and trajectory and to calculate the significance of the coupling terms in an example application of a robot manipulator tracking a part on a moving conveyor. The inertial and velocity coupling terms have been shown to be of significance when the manipulator was considered to be directly driven. A simulation of the robot manipulator following the planned trajectory has been established in order to assess the performance of the independent axis control strategies. The inertial coupling was shown to reinforce the control torque at the corner points of the trajectory, where there was an abrupt demand in acceleration in each axis but of opposite sign. This reduced the tracking error however, this effect was not controllable. A second effect was due to the velocity coupling terms. At high trajectory speeds it was shown, by means of a root locus analysis, that the velocity coupling terms caused the system to become unstable.

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48

Devereux, David. "Control strategies for whole arm grasping." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/control-strategies-for-whole-arm-grasping(02ddb06c-3264-46e1-818a-8632b1bb05c4).html.

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Grasping is a useful ability that allows manipulators to restrain objects to a desired location or trajectory. Whole arm grasps are grasps that use the entire surface of the manipulator to apply contacts to an object. The problem of determining the shape of an object and planning a grasp for that object with a snake-like robot are considered in this work. Existing algorithms that attempt to allow robots to plan and perform whole arm grasps are lacking, they either use restrictive assumptions or have unrealistic demands in terms of required hardware. The work presented here allows even the most basic of robots to plan grasps on unknown objects whilst using a minimum of assumptions.The new developed Octograsp algorithm is a method of gaining information regarding the shape of the object to be grasped through tactile information alone. This contact information is processed using an inverse convex hull algorithm to build a model of the object's shape and position. The performance of the algorithms are examined using both simulations and experimental hardware, it is shown that accuracy errors as low as 3.1% can be obtained. The accuracy of the model depends upon factors such as the complexity of the object and the suitability of the robot. Manipulators consisting of a large number of small links with relaxed rotational constraints outperform other configurations. It is also shown that the accuracy can be improved by between 11% and 17% by contacting the object from multiple orientations, whilst also encircling from multiple positions can provide a very large improvement of between 56% to 86%. These methods allow even the coarse contact information provided by the experimental equipment to attain a model with an accuracy error of only 26%.A second novel algorithm is described that uses the information provided from the first algorithm to plan strong grasps over the desired object. The algorithm takes, on average, 25.1 seconds to plan the grasp. The mean strength of the planned grasps is 0.3816 using the wrench ball measure, this is firmly in the very good region. Several robotic configurations, as well as objects, are used to test the performance of the algorithm. The optimal parameters of the algorithm are investigated by using the results of 51030 different tests. It is again shown that robots that consist of a large number of small links and with high rotational ability perform the best.

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49

Auret, Erika Elizabeth. "Control strategies for citrus postharvest diseases." Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-06192006-084845.

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50

Graciano, José Eduardo Alves. "Real time optimization in chemical process: evaluation of strategies, improvements and industrial application." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-12072016-094348/.

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The increasing economic competition drives the industry to implement tools that improve their processes efficiencies. The process automation is one of these tools, and the Real Time Optimization (RTO) is an automation methodology that considers economic aspects to update the process control in accordance with market prices and disturbances. Basically, RTO uses a steady-state phenomenological model to predict the process behavior, and then, optimizes an economic objective function subject to this model. Although largely implemented in industry, there is not a general agreement about the benefits of implementing RTO due to some limitations discussed in the present work: structural plant/model mismatch, identifiability issues and low frequency of set points update. Some alternative RTO approaches have been proposed in literature to handle the problem of structural plant/model mismatch. However, there is not a sensible comparison evaluating the scope and limitations of these RTO approaches under different aspects. For this reason, the classical two-step method is compared to more recently derivative-based methods (Modifier Adaptation, Integrated System Optimization and Parameter estimation, and Sufficient Conditions of Feasibility and Optimality) using a Monte Carlo methodology. The results of this comparison show that the classical RTO method is consistent, providing a model flexible enough to represent the process topology, a parameter estimation method appropriate to handle measurement noise characteristics and a method to improve the sample information quality. At each iteration, the RTO methodology updates some key parameter of the model, where it is possible to observe identifiability issues caused by lack of measurements and measurement noise, resulting in bad prediction ability. Therefore, four different parameter estimation approaches (Rotational Discrimination, Automatic Selection and Parameter estimation, Reparametrization via Differential Geometry and classical nonlinear Least Square) are evaluated with respect to their prediction accuracy, robustness and speed. The results show that the Rotational Discrimination method is the most suitable to be implemented in a RTO framework, since it requires less a priori information, it is simple to be implemented and avoid the overfitting caused by the Least Square method. The third RTO drawback discussed in the present thesis is the low frequency of set points update, this problem increases the period in which the process operates at suboptimum conditions. An alternative to handle this problem is proposed in this thesis, by integrating the classic RTO and Self-Optimizing control (SOC) using a new Model Predictive Control strategy. The new approach demonstrates that it is possible to reduce the problem of low frequency of set points updates, improving the economic performance. Finally, the practical aspects of the RTO implementation are carried out in an industrial case study, a Vapor Recompression Distillation (VRD) process located in Paulínea refinery from Petrobras. The conclusions of this study suggest that the model parameters are successfully estimated by the Rotational Discrimination method; the RTO is able to improve the process profit in about 3%, equivalent to 2 million dollars per year; and the integration of SOC and RTO may be an interesting control alternative for the VRD process.
O aumento da concorrência motiva a indústria a implementar ferramentas que melhorem a eficiência de seus processos. A automação é uma dessas ferramentas, e o Real Time Optimization (RTO) ou Otimização em Tempo Real, é uma metodologia de automação que considera aspectos econômicos e restrições de processos e equipamentos para atualizar o controle do processo, de acordo com preços de mercado e distúrbios. Basicamente, o RTO usa um modelo fenomenológico em estado estacionário para predizer o comportamento do processo, em seguida, otimiza uma função objetivo econômica sujeita a esse modelo. Embora amplamente utilizado na indústria, não há ainda um consenso geral sobre os benefícios da implementação do RTO, devido a algumas limitações discutidas no presente trabalho: incompatibilidade estrutural entre planta e modelo, problemas de identificabilidade e baixa frequência de atualização dos set points. Algumas metodologias de RTO foram propostas na literatura para lidar com o problema da incompatibilidade entre planta e modelo. No entanto, não há uma comparação que avalie a abrangência e as limitações destas diversas abordagens de RTO, sob diferentes aspectos. Por esta razão, o método clássico de RTO é comparado com metodologias mais recentes, baseadas em derivadas (Modifier Adaptation, Integrated System Optimization and Parameter estimation, and Sufficient Conditions of Feasibility and Optimality), utilizando-se o método de Monte Carlo. Os resultados desta comparação mostram que o método clássico de RTO é coerente, desde que seja proporcionado um modelo suficientemente flexível para se representar a topologia do processo, um método de estimação de parâmetros apropriado para lidar com características de ruído de medição e um método para melhorar a qualidade da informação da amostra. Já os problemas de identificabilidade podem ser observados a cada iteração de RTO, quando o método atualiza alguns parâmetros-chave do modelo, o que é causado principalmente pela ausência de medidas e ruídos. Por esse motivo, quatro abordagens de estimação de parâmetros (Discriminação Rotacional, Seleção Automática e Estimação de Parâmetros, Reparametrização via Geometria Diferencial e o clássico Mínimos Quadrados não-lineares) são avaliados em relação à sua capacidade de predição, robustez e velocidade. Os resultados revelam que o método de Discriminação Rotacional é o mais adequado para ser implementado em um ciclo de RTO, já que requer menos informação a priori, é simples de ser implementado e evita o sobreajuste observado no método de Mínimos Quadrados. A terceira desvantagem associada ao RTO é a baixa frequência de atualização dos set points, o que aumenta o período em que o processo opera em condições subotimas. Uma alternativa para lidar com este problema é proposta no presente trabalho, integrando-se o RTO e o Self-Optimizing Control (SOC) através de um novo algoritmo de Model Predictive Control (MPC). Os resultados obtidos com a nova abordagem demonstram que é possível reduzir o problema da baixa frequência de atualização dos set points, melhorando o desempenho econômico do processo. Por fim, os aspectos práticos da implementação do RTO são discutidos em um estudo de caso industrial, que trata de um processo de destilação com bomba de calor, localizado na Refinaria de Paulínia (REPLAN - Petrobras). Os resultados deste estudo sugerem que os parâmetros do modelo são estimados com sucesso pelo método de Discriminação Rotacional; que o RTO é capaz de aumentar o lucro do processo em cerca de 3%, o equivalente a 2 milhões de dólares por ano; e que a integração entre SOC e RTO pode ser uma alternativa interessante para o controle deste processo de destilação.

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