Made available in DSpace on 2016-06-02T19:05:50Z (GMT). No. of bitstreams: 1 3678.pdf: 5394148 bytes, checksum: 4abd3e7ce4acac9d5890eae3620c06d3 (MD5) Previous issue date: 2011-06-14 / Financiadora de Estudos e Projetos / In recent years, most companies apply techniques of industrial automation with the goal of increasing its efficiency. Increasingly Automated Guided Vehicles (AGVs) are used to transport work in factories and warehouses. The management of these AGV is the key to an efficient transport system. One of the main problems encountered in the management of AGV is the dispatching decision. This work proposes a method of dispatching of AGV with the ability to optimize the performance of flexible manufacturing systems (FMS) in real time. In the dispatching deciding can be chosen to optimize two objectives: makespan or tardiness. When the goal is to optimize the makespan are evaluated variables: distance, number of nodes, the input buffer and output buffer of the workstation. When the goal is to optimize the tardiness are evaluated variables: distance, number of nodes, task chaining, date of delivery. In both cases are also considered the time of the AGVs and the processing times of the workstations, so you can anticipate some decision-making. To perform the tests we used the softwares: Matlab, CPNtools and Automod, which allow simulations of how the method works dispatching AGVs before the method is implemented in factories. Based on the tests, we analyzed the improvement in makespan and tardiness compared to other studies, but also the flexibility of the method in which it is possible to exchange goals in operating time. / Nos últimos anos, mais empresas aplicam técnicas de automação industrial com o objetivo de aumentar sua eficiência. Cada vez mais Veículos Auto Guiados (AGVs) são usados para tarefa de transporte em indústrias e armazéns. O gerenciamento desses AGVs é a chave para um sistema de transporte eficiente. Um dos principais problemas encontrados no gerenciamento dos AGVs é a decisão de despacho. Esse trabalho propõe um método de despacho de AGV com capacidade de otimizar o desempenho de Sistemas Flexíveis de Manufatura (FMS) em tempo real. Na tomada de decisão do despacho podem ser escolhidos dois objetivos para otimização: makespan ou tardiness. Quando o objetivo é otimizar o makespan são avaliadas as variáveis: distância, número de nós, buffer de entrada e buffer de saída das estações de trabalho. Quando o objetivo é otimizar o tardiness são avaliadas as variáveis: distância, número de nós, encadeamento de tarefas, data de entrega do produto. Em ambos os casos também são considerados os tempos dos AGVs e os tempos de processamento das estações de trabalho, para que seja possível adiantar algumas tomadas de decisões. Para realizar os testes foram usados os softwares MatLab, CPNtools e Automod, os quais permitem que simulações do funcionamento do método de despacho de AGVs antes que o método seja implementado em fábricas. Com base nos testes realizados, analisou-se as melhoras no makespan e tardiness em comparação com outros trabalhos, como também a flexibilidade do método no qual é possível a troca de objetivos em tempo de operação.

Since 1970s, ever growing attention has been devoted by worldwide researchers and practitioners to the investigation of job release control. However, the need for control of flow of job/wafer into the wafer fabrication system is identified in the late 1988s. Subsequently, many release policies are developed and presented in the literature for improving its performance with respect to cycle time and throughput. Even though it is pointed out in the literature that there is a need for the development and analysis of policy that control the flow of job/wafer through the manufacturing process, still there is no exhaustive study in view of the previously developed release policies in the literature. Moreover, many new opportunities have evolved in the field of release policy in wafer fabrication industry due to the advancement in technology and computer science. It implies that near real-time decision making for efficient release policy is possible based on the global factory state. However, it appears from the literature that still to date the release policies, which are employed in real wafer fabrication system, are usually based on the static information. Release control/policy is emerging as an important research topic in the wafer fabrication industry given the extremely large capital investment and sales revenue of this industry. Release policy also hold practical significance for manufacturing managers, since neglecting it can lead to wide variations in shop workloads, can cause excessive backlogs, accomplishment of orders will be either too early or too late and there can be frequent need for expediting. All the challenges associated with the performance of the wafer fabrication system discussed here and the puzzle around the release policies and its impact on the wafer fabrication process, this research attempts to investigate existing release policies and proposing a few efficient release policies based on the knowledge gained from the existing release policies strength and weakness. Based on the insights gained from the existing release policies, three new closed loop release policies constant workload (CONSTWL), constant batch machine workload (CONSTBWL) and layer wise control (LWC) are developed by considering the parameters: workload in general, workload in batch machine, and re-entrant characteristics of the wafer fabrication system respectively. The conceptual significance in favour of these proposed closed loop release policies in improving performance of the wafer fabrication system is also outlined in this study. In the literature, few researchers clearly indicate that dispatching rule(s) influence the performance of wafer fabrication system either independently or in integration with release policies. Therefore, to empirically validate this fact, release policy is integrated with dispatching rule particularly applying on bottleneck (discrete processing machine) work station in this study. With these, the aims of proposed release policies are to efficiently improve the system performances in terms of average cycle time, standard deviation of cycle time and throughput. Accordingly, a simulation model is proposed and developed using Arena software for evaluating the performance of release policies in integration with dispatching rule applied on bottleneck work station in wafer fabrication environment. Further, to set the values of parameters in the simulation model, the cause and effect analysis is explored in this study by considering eight critical parameters or factors of the simulated wafer fabrication environment. It includes arrival rate, arrival distribution, processing time, maintenance schedule, operator’s schedule, batch size, dispatching rule and release policy. Simulation based cause and effect analysis not only helps in setting up the values of parameters in the proposed simulation model, but it also helps in strengthening the face validity of the developed simulation model. The verification and validation of the developed simulation model, which is a vital and fundamental aspect of simulation is discussed in detail in this study. Based on the analysis and the results observed from the cause and effect analysis, some modifications are incorporated and subsequently, the parameters values are set in the proposed simulation model for evaluating the performance of release policies integrating with dispatching rules. A series of simulation experiments are conducted using the proposed simulation model with systems conditions such as product mix, complexity of the process, level of machine unreliability, and system congestion level to study the relative effects of each of 18 release policies (one open loop release policy, 14 existing closed loop release policies, and 3 proposed release policies) in integration with dispatching rules (FIFO, LIFO and SRPT), considered in this study, at various throughput levels in the wafer fabrication environment. Particularly, the relative effect of integrating release policies and the dispatching rules are observed and analysed in terms of (a) the effect of dispatching rule on release policy, and (b) the effects of release policies on dispatching rules. It is observed from the overall inferences that dispatching rule: SRPT outperformed both FIFO and LIFO dispatching rule for all the considered release policies, except for the release policy: ‘TOTAL_CT’. Additionally, it is observed that for each of the eighteen release policies integrated with considered, the dispatching rule: SRPT produces less WIP inventory at the bottleneck work station for all throughput levels. The maximum deviation in delay (cycle time) is produced by dispatching rule: LIFO in all the release policies considered except for the release policy: ‘TOTAL_CT’ in which dispatching rule: SRPT produces maximum deviation in delay. Moreover, it is observed that the difference in mean delay with all three dispatching rules (FIFO, LIFO and SRPT) increases with the increase in throughput levels. Furthermore, it is observed that the throughput rate under all release policies (except ‘TOTAL_CT’) is more for dispatching rule: SRPT in comparison with both dispatching rules: FIFO and LIFO for nearly the same threshold values. The experimental results showed that proposed release policy: LWC reliably improves the system performance followed by the proposed release policy: CONSTWL and CONSTBWL with respect to both mean delay and standard deviation for corresponding throughput levels in wafer fabrication system. The characteristics of the proposed release policy: LWC are summarized and the same is presented as follows because this is proven to be best release policy among all the release policies considered in the proposed simulation model. The proposed release policy: LWC is a new measure of the work quantity on the shop floor system, which takes into account the location of jobs/wafers along the production line by employing re-entrant property of wafer fabrication system. As a result, it offers quick response to the stochastic events of the manufacturing system and can compensated the system disturbances in time. The proposed release policy: LWC offers more efficient control of flow of job/wafer in the wafer fabrication system with reduced delay (cycle time) and the standard deviation of delay (cycle time) for a given throughput level in comparison with almost all the release policies considered in this study in integration with all three dispatching rules considered and applied on bottleneck work station. For instance, from the analysis of simulation model, the proposed release policy: LWC reduces the average delay up to 98%, 95%, 90%, 89%, 49%, 35%, 21%, 17%, 13%, 12%, 10%, 9%, 9%, 9%, 6% and 4%, and reduces the standard deviation of delay up to 96%, 98%, 94%, 93%, 34%, 22%, 4%, 13%, 11%, 6%, 9%, 14%, 4%, 4%, 10% and 7% for a given throughput level, respectively in relation to other release polices: FRCP, EWIP, TOTAL_CT, PWR, EWC, DRCP, CONLOAD, WIPLCtrl, Droll, DEC, CONWIP, SA, RCONWIP, WR, CONSTBWL and CONSTWL respectively in integration with dispatching rule: SRPT. These improvements can also be understood from another aspect, that is, LWC can increase the system throughput rate for a given cycle time. The improvement is statistically significant according to the two sample t-test for all throughput values with a 95% confidence level. As the improvement of the proposed release policy: LWC is relatively less on the proposed release policies: CONSTWL and CONSTBWL with respect to mean delay, it can be inferred that the performance of CONSTWL and CONSTBWL is relatively better than other existing closed loop release policies for the scenarios considered in the simulation model. However, the best release policy: LWC provides satisfactory performance in comparison with other release policies for almost all scenarios considered in the simulation model. It is important to note that these proposed release policies can be easily applied in real wafer manufacturing systems because it possesses a simple logic and only the reference level need to be prescribed. The performance of four existing closed release policies that are FRCP, EWIP, TOTAL_CT and PWR are relatively worst in comparison with open loop release policy CONST. This is contradicting to the conclusions given in the literature by many authors that closed loop release policies are always better than open loop release policy with respect to cycle time and throughput measures. In fact, a reasonable closed loop release policy can provide better results than open loop release policy, if its objective and the release parameter are designed carefully, so that the release parameter can respond effectively to the dynamics of the manufacturing system. The reason for worst performance of these four existing closed loop release policies in comparison with open loop release policy and other existing policies is described in detail in this study. In order to see the impact of dispatching rules on a particular work station, batch machine work station, which usually has highest processing time in fabrication process, is considered in this study. The entire simulation experiments are replicated in the same manner except the basis that dispatching rules are applied on batch machine work station instead of bottleneck work station. Based on the analysis of the simulation results, the important observations are as follow: It is observed from the overall inferences that the influence of dispatching rules when applied to batch processing machine (diffusion) work station was not much on individual release policies, since the performance of all three dispatching rules provides nearly same performance at higher throughput level in the proposed simulation model. However, the performances of dispatching rule: SRPT in integration with all release policies considered in this study are summarized here because it produces less mean delay at most of the throughput values. In addition, from the analysis of simulation model, the proposed release policy: LWC reduces the average delay up to 97%, 93%, 87%, 85%, 22%, 17%, 15%, 15%, 13%, 11%, 10%, 10%, 9%, 6%, 6% and 2%, and reduces the standard deviation of delay up to 96%, 97%, 92%, 93%, 21%, 5%, 10%, 2%, 16%, 7%, 14%, 4%, 20%, 10%, 10% and 11% for a given throughput level, respectively in relation to FRCP, EWIP, PWR, TOTAL_CT, EWC, DEC, Droll, CONLOAD, SA, RCONWIP, WIPLCtrl, WR, DRCP, CONWIP, CONSTWL and CONSTBWL in integration with dispatching rule: SRPT, when applied on batch processing machine work station. The improvement is statistically significant according to the two sample t-test for most of the throughput values with a 95% confidence level. It is observed from overall inferences that the performance of all the release policies, considered in this study, in integration with dispatching rule: SRPT is better with respect to both mean delay and standard deviation of delay, when the dispatching rule is applied on the bottleneck (discrete machine, lithography) work station in the proposed simulation model. The performance of most of the release policies, considered in this study, in integration with dispatching rule: LIFO is better with respect to standard deviation of delay, when the dispatching rule is applied on the batch (batch machine, diffusion) work station. These results indicate that there is an influence of dispatching rule on the performance of wafer fabrication system if applied on batch machine work station or on bottleneck work station in integration with release policies. In addition, the effects of dispatching rules are highly dependent upon both the type of release policy used and the work station on which it is applied. Overall, the performance of the proposed release policies is proven to be very effective to system variability’s in scenarios considered in the simulation model. The significant impact of the choice of release policies on wafer manufacturing system performance is justified by the simulation experiments. It can be safely concluded that the efficient closed loop release policies that utilizes system information carefully based on the global factory state data can significantly improve the performance of wafer fabrication system. This thesis provides an extensive literature review covering several aspects of wafer fabrication process. Thereafter, a three new efficient closed loop release policies are developed and their workability are conceptually demonstrated with a framework and a flow diagram. The strength and the weakness of the existing release policies are conceptually highlighted and later it is proven to be true through comprehensive simulation study. A simulation model is developed by considering all the real-life fabrication environment for evaluating the performance of release policies in integration with dispatching rules. Cause and effect analysis is explored in proposed simulation model to set the parameters value. A series of simulation experiments are also constructed to empirically justify the conceptual significance of the proposed release policies.

La première thématique développée dans ce mémoire vise à développer de nouveaux algorithmes pour la commande des éoliennes reposant sur une machine asynchrone à double alimentation et des convertisseurs multi niveaux. Deux stratégies de contrôle direct du courant, basées sur l’Hystérésis à Zones Carrées et l’Hystérésis à Zones Circulaires (HZCi) ont été proposées. Celles-ci consistent à appliquer des vecteurs de tension appropriés pour contrôler les puissances actives et réactive générées et permettent également d’équilibrer les tensions du bus continu interne des convertisseurs. Des résultats de simulation et d’expérimentation montrent que la stratégie basée sur l’HZCi est meilleure en termes de forme d’onde et de contenu harmonique des tensions de sortie.La seconde concerne la supervision et la gestion des puissances active et réactive dans une ferme éolienne au vu de son intégration dans un réseau électrique. Cette supervision centralisée est assurée par un algorithme qui distribue les consignes de puissance aux éoliennes de la ferme de manière proportionnelle. Ces références sont fonction de la capacité maximale de production de l’éolienne. Pour cela, une analyse des transits de puissance dans le système éolien à base de la machine asynchrone à double alimentation a été effectuée. Elle a permis de déterminer la caractéristique (P, Q) du générateur et de calculer ses limites de compensation en termes de puissance réactive. Une gestion locale des puissances de chaque éolienne a été développée permettant ainsi une répartition des puissances entre le stator de la machine et le convertisseur coté réseau en considérant plusieurs modes de fonctionnement du système éolien / This research work deals with two topics conditioning the large scale development of wind turbines into electrical grids. The first is devoted to the development of new algorithms for the control of Doubly Fed Induction Machine (DFIM) based wind energy conversion systems. Two direct current control strategies have been proposed and are based on the hysteresis square areas (HZCA) and hysteresis circular areas (HZCI). Both strategies apply an appropriate voltage vector to control the active and reactive powers delivered to the grid, and also, to balance the voltages of the inner DC bus converter. Simulation and experimental results show that the HZCI strategy is better than HZCA in terms of output voltage waveforms and harmonic contain.The second topic is dedicated to the active and reactive powers supervision in a wind farm in order to supply prescribed power references from the grid operator. This supervision is ensured by a centralized algorithm that distributes power references between wind turbines in a proportional way. These references are calculated according to the maximum production capacity of wind turbines. An analysis of the power flow in the DFIM based wind energy system has been made to identify the (P, Q) characteristic and to calculate limits in terms of reactive power compensation. The local power management of each wind system has been developed allowing the powers distribution between the stator of the DFIM and the grid side converter by considering several operating modes of the wind generator

Le développement massif des énergies renouvelables intermittentes dans les systèmes de puissance affecte le fonctionnement des systèmes électriques. En raison des techniques limitées et des investissements nécessaires pour maintenir le niveau de sécurité électrique actuel, les questions liées à l'envoi, à la stabilité statique et dynamique pourraient arrêter le développement de ces sources. Le sujet de la thèse est de développer un outil pour mesurer l'incertitude sur la disponibilité de la puissance produite par les générateurs photovoltaïques dans un réseau urbain. Premièrement, l'incertitude est modélisée par l'étude de la nature incertaine de la PV énergie production et de la charge. Avec les méthodes stochastiques, on calcule la réserve de puissance (OR) un jour d'avance en tenant compte d'un indice de risque de fiabilité associé. Ensuite, l'OR est distribué en différents générateurs (générateurs photovoltaïques actifs et micro-turbines à gaz). Afin de minimiser le coût opérationnel total et/ou les émissions équivalentes de CO2, une planification optimale et une répartition quotidienne de l'OR dans différents générateurs d'énergie sont mises en œuvre. Enfin, un logiciel libre «Un système de gestion de l'énergie convivial et un superviseur de la planification opérationnelle» est développé à partir de l'interface utilisateur graphique de Matlab pour conceptualiser le fonctionnement global du système. / The massive development of intermittent renewable energy technologies in power systems affects the operation of electrical systems. Due to technical limitations and investments needed to maintain the current electrical security level, issues related to dispatching, static and dynamic stability could stop the development of these distributed renewable energy sources (RES). The subject of the PhD is to develop a tool to study the uncertainties of PV power and load forecasting in an urban network. Firstly, the uncertainties are modeled by studying the uncertainty nature of PV power and load. With stochastic methods, the day-ahead operating reserve (OR) is quantified by taking into account an associated reliability risk index. Then the OR is dispatched into different power generators (active PV generators and micro gas turbines). To minimize the microgrid total operational cost and/or equivalent CO2 emissions, day-ahead optimal operational planning and dispatching of the OR into different power generators is implemented. Finally, a freeware “A User-friendly Energy Management System and Operational Planning Supervisor” is developed based on the Matlab GUI to conceptualize the overall system operation

The thesis deals with air cargo transport and its use by a chosen company. The theoretical part gives detailed information on air cargo transport and its providers. The practical part focuses on the use of air cargo transport by a specific company. It describes a system for orders processing and dispatching. The system is demonstrated on an example of a consignment transported by air to Bolivia. The possible improvements of the system are suggested. The practical part also analyses the transport of all consignments within the specific period. The data are used for introducing the company to several transport companies aiming to enter cooperation. The offers received from the transport companies are compared and evaluated.

The author designed the dispatching system structure of metalcutting FMS, at that it was placed high emphasis on hardware recourses, in the course of study. The author analyzed present information transmission and encoding methods in FMS: uniform codes, codes with control at par, optimum code, Chudakov code and Huffman - Liberman codes. The last one is the best for given problem. It was created the original Huffman - Liberman codes synthesis algorithm, which is conformed to present hardware level of development. On the base of this algorithm it was coded the Huffman - Liberman codes synthesis program, which was taken out the Certificate of state program registration № 2013612951. Huffman - Liberman codes for Russian, Ukrainian and English alphabets and CNC machines executive program were synthesized with the help of this program. The results of the work were published in four scientific-technical journals. In the course of study the author designed automatic guided vehicle control system, which involves rate of movement, motion path, positioning and acceleration -braking control systems. The latest two systems are original, which are designed by the author. Designed positioning control system allows to program the break time of automatic guided vehicle and avoid missing of stop place. This system took out a patent of Russian Federation № 130540. Designed acceleration -braking control system allows to change automatic guided vehicle speed fluently (without stage), and to change rate of acceleration -braking and maximum speed depending on cargo tonnage. This system took out a patent of Russian Federation № 132278. Engineering solutions, introduced in the work, can be used at any metalcutting FMS. / В ходе научной работы была разработана структура системы диспетчирования ГАЦ механообработки, при этом особое внимание было уделено средствам технического обеспечения разработанной системы. Были рассмотрены и проанализированы существующие методы передачи и кодирования информации в ГПС: равномерные коды, коды с контролем по паритету, оптимальные коды, коды Чудакова и коды Хаффмена - Либермана. Наиболее оптимальными для решения поставленных задач являются последние. Был создан оригинальный алгоритм синтеза кодов Хаффмена - Либермана, отвечающий современному уровню развития вычислительной техники, на основе которого была написана программ синтеза кодов Хаффмена - Либермана, получившая Свидетельство о государственной регистрации программы для ЭВМ № 2013612951. С помощью данной программы были получены коды Хаффмена - Либермана для управляющих программ станков ЧПУ, русского, украинского и английского алфавитов. Результаты работы были опубликованы в трех научно-технических журналах. В ходе работы также была разработана система управлением робокаром, включающая в себя системы управления скоростью движения, траекторией движения, позиционирования и разгоном - торможением робокара, при этом две последние системы являются оригинальными, разработанными автором диссертации. Разработанная система управления позиционированием робокара, в отличии от существующих аналогов, позволяет программировать время выстоя робокара и избежать "проскока" требуемой позиции остановки. На данную систему был выдан Патент РФ № 130540. Разработанная система управления разгоном - торможением робокара, в отличие от существующих аналогов, позволяет осуществлять регулирование скорости привода плавно, без ступеней, а также способна изменять темп разгона - торможения и максимальную скорость автоматически в зависимости от массы перевозимого груза. На данную систему был выдан Патент РФ № 132278. Технические решения, предложенные в диссертации могут рассматриваться как типовые для ГАП механообработки.

In this work, the current state and prospects of development of urban passenger transport in the operating conditions of the city of Yekaterinburg of the Sverdlovsk region are investigated and analyzed. The analysis and evaluation of the management and organization of passenger traffic to urban passenger transport in the city of Yekaterinburg. The solution of the problem of dispatching control and organization of passenger traffic in the urban cycle by mathematical modeling and optimization is considered. A General view of the simulation model of the automated system of urban passenger transport management by levels is developed. It also proposes the structure of management and organization of urban passenger transport. / В данной работе исследована и проанализирована современное состояние и перспективы развитие городского пассажирского транспорта в условиях эксплуатации города Екатеринбург Свердловской области. Изложена анализ и оценка эффективности управления и организации пассажиропотока городским пассажирским транспортам в городе Екатеринбург. Рассмотрена решение проблемы диспетчеризации управления и организации пассажирских перевозок в городском цикле математическим методом моделирования и оптимизации. Разработан общий вид имитационной модели автоматизированной системы управлении городского пассажирского транспорта по уровням. А также предлагается структура управления и организации городского пассажирского транспорта.

La tesis estudia la evolución del parque de generación de energía eléctrica durante el franquismo (1940-1975). En este período comenzó la formación de un sistema unificado de explotación, y durante su desarrollo se pasó de 1.731Mw a 25.467Mw. El sistema que se denominó “autorregulación”, permitió la coexistencia de las empresas eléctricas privadas, agrupadas alrededor de UNESA y el INI en su vertiente eléctrica. Sin embargo, las decisiones y la política eléctrica, y más tarde energética, estuvo directamente influida por el gobierno. Se analiza la importancia de las fuentes (hidráulica, carbón, fuel oil, gas natura, nuclear) de energía primaria en la generación de energía eléctrica. Asimismo, se estudia, aunque no de manera exhaustiva el impacto del medio ambiente y sus consecuencias y efectos a largo plazo. Todo ello se desarrolla en el contexto histórico pertinente bajo una vertiente técnico-económica. / The thesis studies the evolution of the power generation system of electricity, during the Franco’s Regime (1940-1975). In this period, it began the construction of a unified system of exploitation, where the power installed was moved from 1.731Mw to 25.467Mw. The system was called "self regulation", allowing the coexistence of private electric companies, grouped around UNESA and the INI in its electrical aspect. However, the decisions and the power policy, and later on the energy, was directly influenced by the government. It discusses the importance of the primary energy sources (hydro, coal, fuel oil, natural gas, nuclear) in electric power generation. However, it is not intended to illustrate a comprenhensive explanation of the environmental impact and its consequences and effects long term. To sum up, all this takes place in the relevant historical context in a technical and economical perspective.

Intention of this thesis is the Workcenter PKS system implementation project in Precheza a.s., Přerov, implementation outputs and assessment of implementation advantages for the company and its employees. Currently the WPKS system has been purchased and comes over from the analytic phase to the implementation phase. In the designing section I will concentrate on implementation detailed planning, i.e. on detailed elaboration of production process maps, on process sequence designing, project team members and on drawing the total WPKS system implementation schedule. Also, financial contribution of the project will be assessed from the cost and effectiveness point of view.

The thesis deals with the preparation of the implementation and management of building central dispatching of rail traffic management Prague. The thesis contains the selected part of building technological project together with appropriate drawings. The project addresses mainly the rough construction of the mainbuilding.The aim of this thesis is to design appropriate and effective way of realization of construction depending on local conditions.