Made available in DSpace on 2015-05-08T14:53:17Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3747541 bytes, checksum: 321b5f29863e2f68953902273ae4cb9f (MD5) Previous issue date: 2011-08-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main goal of this dissertation is to design and implementation of an Operational Simulation Model (OSM) of the handling of raw material in an Integrated Steelmaking Plant, considering operations of receiving, unloading, stocking, handling and supplying the different raw materials related to the production process with an operational perspective. The aim of this focus is to help in the decision making of the team controlling the ore inventory. The construction of this computer model was based on the methodological framework developed by Coelho, which passed through problem formulation, planning and elaboration of a detailed specification of the model. The OSM showed that most of the valid concepts for simulations with a strategic focus do not present relevance from an operational point of view. The advantage of the OSM is the fact that it is not random or stochastic, but deterministic. The methodology allowed the model elaboration with a minimum effort and great consistency. The results of scenarios with scheduled equipment stops have shown the simulator s flexibility, with previous identification of bottlenecks and allowed the decision making of corrective actions for avoid them on real situations. The filling of the stockyard map using results of consistent scenarios was a great advance in order to automate this activity. The correct behaviour of the simulator allowed the raw material yard team to consider the well succeeded study. / O objetivo principal desta dissertação é construir um modelo de simulação operacional do manuseio de matérias-primas de uma usina siderúrgica integrada, contemplando as operações de recebimento, descarga, estocagem, manuseio e abastecimento das diversas matérias-primas pertinentes ao processo produtivo, com foco operacional, visando auxiliar a tomada de decisões operacionais da equipe que controla o pátio. A construção desse modelo computacional se baseou na estrutura metodológica desenvolvida por Coelho, que passou pela formulação do problema, planejamento do estudo e pela elaboração de uma especificação detalhada do modelo. O modelo de simulação operacional revelou que grande parte dos conceitos válidos para simulações com foco estratégico não representa tanta relevância sob o ponto de vista operacional. Mas a vantagem do modelo de simulação operacional é a ausência de aleatoriedade, não é estocástico, mas sim determinístico. A metodologia inédita, utilizada para desenvolvimento do modelo do pátio de matérias-primas, permitiu a elaboração do modelo com o mínimo de retrabalho e com grande consistência. Os resultados dos cenários, com paradas programadas dos equipamentos, mostraram a flexibilidade do simulador, permitindo a identificação prévia de gargalos e possibilitando a tomada de ações corretivas para evitá-los nas situações reais. O preenchimento do mapa do pátio, a partir de resultados de cenários consistentes, foi um grande avanço, no sentido de automatizar esta atividade. O comportamento correto do simulador permitiu que a equipe do pátio de matérias-primas considerasse o estudo muito bem sucedido.

A manipulação de materiais é uma das tarefas em que comumente empregam-se robôs para substituir o trabalho humano, dadas algumas vantagens como: maior precisão na manipulação de cargas e maior velocidade de execução da tarefa, bem como por aumentar a segurança do operador. Apesar dessas vantagens, os dispositivos robóticos são largamente empregados apenas em situações em que velocidade e precisão são indispensáveis, em outros casos, os equipamentos convencionais (como talhas, gruas e macacos hidráulicos) e os dispositivos específicos (aqueles fazem uso de molas e contrapesos), vêm sendo utilizados nas tarefas cotidianas, principalmente pelo fato de, entre outros, serem menos dispendiosos. Comparando-se estas duas soluções disponíveis, tem-se que os equipamentos tradicionais, apesar de sua simplicidade e versatilidade de movimentação, apresentam limitações quando são exigidas precisão e eficiência, enquanto os dispositivos robóticos apresentam alta complexidade tanto no projeto quanto na operação, representando uma solução cara e com movimentação restrita pela programação. Neste contexto, o presente trabalho tem por objetivo estudar e propor uma solução intermediária entre a solução convencional e a robótica. O foco do estudo é o projeto de um dispositivo simplificado, que faz uso de molas e de um sistema de alavanca para manipular cargas. Um estudo preliminar desse mecanismo mostrou imperfeições quanto à força de contrabalanceamento. Com o intuito de corrigir esse erro foi usado um sistema de controle, que é constituído por um motor elétrico, um mecanismo de correção, sensores e um módulo controlador. O dispositivo proposto apresenta um controle simplificado, vez que a movimentação é feita exclusivamente pelo operador, possibilitando assim que o dispositivo apresente um baixo consumo de energia. Um protótipo é desenvolvido e os testes demonstraram a eficácia da solução. / The material handling is one task in which robot is commonly employed to replace the human work because it has some advantages such as, higher precision in the handling and higher speed of the task, and to increase operator safety. Despite these advantages, the robotic device is most employed only in situation that speed and precision are essential; in other cases, the conventional equipments (such as hydraulic jacks, cranes and pulley systems) and the specific device (which use springs and counterweight), have been used in daily tasks mainly because of they are less expensive. Comparing these two solutions, it is possible to say that the conventional devices, despite its simplicity and guidance, have limitations when the task requires precision and speed, while the robotic solution has higher complexity in both design and in operation, representing an expensive solution with a programming that restrict the movement. In this context, the present work has the objective the study and development of an intermediate solution between the conventional solution and the robotic device. The proposed study is based on a simplified device, which uses springs and a lever system to handle material. A preliminary study on this mechanism shows imperfections in balance force. In order to correct this error, a control system is used. The control system is constituted by an electric motor, a correcting mechanism, sensors and a controller. The proposed device presents simple control because movements are responsibility of the human operator moreover presents low power consumption, due to the use of springs. A prototype is developed and tests demonstrate the effectiveness of the solution.

This thesis is focused on design of an electric stand-on low lift pallet truck with regards to operators ergonomical needs. The goal of this thesis is to design aestheticaly pleasing machine while regarding the technological requirements.

The main goal of a study is to rationalize organization of production and material handling in company AVL Moravia s.r.o. via material flow intensity analysis. Analysis results in suggesting new organization of production and economical rating of the suggestion.

This thesis focuses on control strategies for intralogistics transport systems. It evaluates how switching from central to decentral dispatching approaches influences the performance of these systems. Many ideas and prototypes for implementing decentral control have been suggested by the scientific community. But usually only the qualitative advantages of this new paradigm are stated. The impact on the performance is not quantified and analyzed. Additionally, decentral control is often confused with distributed algorithms or uses the aggregation of local to global information. In the case of the latter, the technological limitations due to the communication overhead are not considered. The decentral prototypes usually only focus on routing. This paper takes a step back and provides a generic simulation environment which can be used by other researchers to test and compare control strategies in the future. The test environment is used for developing four truly decentral dispatching strategies which work only based on local information. These strategies are compared to a central approach for controlling transportation systems. Input data from two real-world applications is used for a series of simulation experiments with three different layout complexities. Based on the simulation studies neither the central nor the decentral dispatching strategies show a universally superior performance. The results depend on the combination of input data set and layout scenario. The expected efficiency loss for the decentral approaches can be confirmed for stable input patterns. Regardless of the layout complexity the decentral strategies always need more vehicles to reach the performance level of the central control rule when these input characteristics are present. In the case of varying input data and high throughput the decentral strategies outperform the central approach in simple layouts. They require fewer vehicles and less vehicle movement to achieve the central performance. Layout simplicity makes the central dispatching strategy prone to undesired effects. The simple-minded decentral decision rules can achieve a better performance in this kind of environment. But only complex layouts are a relevant benchmark scenario for transferring decentral ideas to real-world applications. In such a scenario the decentral performance deteriorates while the layout-dependent influences on the central strategy become less relevant. This is true for both analyzed input data sets. Consequently, the decentral strategies require at least 36% to 53% more vehicles and 20% to 42% more vehicle movement to achieve the lowest central performance level. Therefore their usage can currently not be justified based on investment and operating costs. The characteristics of decentral systems limit their own performance. The restriction to local information leads to poor dispatching decisions which in return induce self-enforcing inefficiencies. In addition, the application of decentral strategies requires bigger storage location capacity. In several disturbance scenarios the decentral strategies perform fairly well and show their ability to adapt to changed environmental conditions. However, their performance after the disturbance remains in some cases unpredictable and relates to the properties of self-organizing complex systems. A real-world applicability has to be called into question.

Im Rahmen des Forschungsvorhabens wurde das Wirken von Autokorrelation auf das Verhalten von Materialflusssystemen anhand von Realdaten analysiert. Hintergrund waren theoretische Untersuchungen, die einen deutlichen Einfluss von abhängigen Ereignissen auf die Leistung von Materialflusssystemen erkennen lassen. Mit Hilfe der Projektpartner konnte eine große Menge von Echtdaten zusammengetragen werden. Insgesamt wurden 52 Datensätze auf zeitliche Abhängigkeiten der Ereignisse untersucht. Dabei bestätigte sich die Vermutung, dass Autokorrelation durch z. B. Batchbildung oder Prioritätsregeln allgegenwärtig in Erscheinung tritt. In ca. 95 % aller Datensätze konnte signifikant Autokorrelation nachgewiesen werden. Im Rahmen der Untersuchung konnten eine Reihe unterschiedlicher Korrelationsstrukturen nachgewiesen werden. Diese unterschieden sich sowohl in der Stärke, in der Ausprägung (positiv oder negativ) als auch im Abklingverhalten. Der größte Einfluss auf das Systemverhalten geht von der Stärke und der Ausprägung der Autokorrelationskoefizienten aus. Im Rahmen des Projektes konnten unterschiedliche Verfahren zur Erzeugung autokorrelierter Ereignisse identifiziert und bewertet werden. Beispielhaft zu erwähnen ist die TES-Methode, der Minification- bzw. Maxification-Ansatz oder spezielle Markov-Ketten. Als am besten geeignet hat sich der sog. ARTA-Ansatz herausgestellt. Der ARTA-Ansatz wurde in einer Java-basierenden Software-Bibliothek namens „JARTA“ umgesetzt. Diese ist frei verfügbar sowie variabel und einfach einsetzbar. Durch das Forschungsvorhaben wurde das Bewusstsein um das Auftreten und Wirken von Autokorrelation in logistischen Systemen geschärft. Projektpartner bestätigen, dass durch gezielte Untersuchung auf Abhängigkeiten Fehler bei der Systementwicklung und beim Systembetrieb verringert werden konnten.

Currently, customers are exerting a lot of pressure on companies by demanding for best product quality, customized products, reduced product lead time and reliable product delivery. Therefore, for companies to be highly competitive, there is need to improve productivity and delivery performance by having an efficient material flow. Nevertheless, the task of making the material to flow efficiently throughout the manufacturing process up to when the customer receives the product is not easy. To solve this, companies are focusing on the material handling system as it has an impact on efficient material flow and productivity. Hence, the aim of this project was to explore how an internal material handling system can be improved to guarantee a better delivery performance. To fulfil the aim, a single case study was undertaken at a dairy food producing company in Jonkoping. The information on the subject area was obtained through interviews, observation at the company and an extensive literature review. The information that was obtained was assessed in accordance with the framework of the project that includes; principles and physical elements used for designing a material handling system, software and information, and human and management. Combined analysis of the findings from the empirical study and the extensive literature review helped to identify the problems faced in an internal material handling system of the company. This was followed by identifying ways of improving material handling system and thereafter, improvement suggestions were made targeting enhancement of the delivery performance of the system. In conclusion, the findings indicate that improvement of an internal material handling system does not only depend on improving the physical attributes of the system, far from it, it is more dependent on having an efficient and effective information system. Another factors that came out is that there should be a proper integration of the material handling system and the workers operating the system. From a systems perspective this research has added information sharing and human and management to the one dimensional physical elements improvement of a material handling system.

Återvinning av olika varor i dagens samhälle är viktigt för att uppnå minskad miljöpåverkan. Genom att minska uttaget av jungfruligt material och istället använda återvunnet material kan en positiv klimatpåverkan erhållas. Att eliminera linjära materialflöden till fördel för cirkulära flöden kan ekonomisk vinning uppfyllas via affärsmodeller inom cirkulär ekonomi. Byggsektorn står för en betydande del av miljöpåverkan och resursanvändningen, samt genererat avfall i samhället. Därmed finns stora möjligheter att öka cirkularitet genom bättre system för återvinning och därmed främja en mer hållbar framtid. Från NCC gavs ett uppdrag med syfte att undersöka hur stor andel återvunnet material som byggdes in i deras bostadsprojekt. Genom intervjuer med deras leverantörer undersökte denna studie hur stor andel återvunnet material som deras mest använda byggvaror bestod av. Dessa byggvaror var betong, armering, mineralull, cellplast, gips och kök. Vidare undersöktes vilka möjligheter till återvinning som fanns för respektive vara. Syftet var också att, utöver detta, finna mer miljövänliga alternativ för byggbranschen i allmänhet och i synnerhet för de produkter som i dagsläget har störst förbättringspotential. Resultatet visar att andelen återvunnet material för respektive byggvara var varierande, från 0 % till 96 %. Tillsammans bidrar dessa värden till en total andel för NCC’s bostadsprojekt på 8,5 %. Kunskapen och möjligheten till att öka andelen återvunna material som byggvarorna innehåller finns hos leverantörerna. En faktor till detta var att andrahandsvärdet varierade stort samt att det saknas ekonomiska incitament för att sortera byggavfallet. Slutsatsen är därför att det krävs en ökad kostnad för att ta ut jungfruligt material i kombination med att det måste kosta mer att deponera. Med andra ord, förbrukat material ska inte ses som avfall utan som en resurs för att cirkulär ekonomi ska kunna förverkligas i samhället och därmed bidra till positiv miljöpåverkan och förbättrad resurshushållning. Utbildning, samarbete och personligt engagemang är faktorer som krävs för att denna samhällsomställning ska kunna ske. / Recycling of waste is important for the environment in today ́s society. Through less use of new raw material and increased use of recycled material, the climate change can be battled. To eliminate linear flow of material in favour of circular is a part of circular economy. The construction industry contributes to a significant part of both the energy consumption and the amount of waste, and therefore has great opportunities to recycle NCC wants to know how much recycled material they used in their housing projects. Through interviews with their suppliers, this study investigates how much recycled material some of their most used building goods (for example concrete, reinforcement and isolation) contained. Further, the opportunities for recycling of the different types of building goods were analysed. The purpose was also to find more eco-friendly alternatives to the construction industry in general and in particular to the goods which had the largest potential of improvement. The result showed that the proportion of recycled material varied and the total proportion for NCC’s housing projects was low. The knowledge and the opportunities to increase the proportion is known by the suppliers but the majority of the building goods consists a general low proportion. One factor was that the second hand value was varied. Another was that there were no incentive for recycling, which leads to a lack of motivation at the worksite. The conclusion is therefore that waste should be seen as a resource in order to implement circular economy to a greater extent and to contribute to the climate in a positive way. Education, collaboration and personal engagement is factors which is needed to fulfil this adaptation of the society.

[pt] O presente trabalho, propõe um procedimento de Avaliação de Integridade Estrutural (AIE) nível I aplicado a estruturas de grande porte, e relaciona com a AIE com a Análise de Risco (AR) através de um modelo de Lógica Nebulosa. A partir de uma AIE nível I o cálculo da Vida Residual (VC) é feito, considerando os fenômenos de danos por fadiga, corrosão e fadiga-corrosão. A VC é comparada com uma Vida Desejada (VD), a qual é obtida da matriz de risco. Se VC é menor que a VD, recomenda-se fazer uma AIE nível II, ou fazer um programa de substituição do equipamento. Se VC é maior que VD determina-se um Tempo de Inspeção (T) baseado na Análise de Risco. A VD, que é a mínima vida residual aceitável em uma estrutura de grande porte, é determinado de uma Análise de Risco. Para isso, o especialista construi uma matriz de risco, na qual, indicam-se os diferentes níveis de risco aceitáveis para as estruturas. Para cada nível de risco associa-se uma VD e uma probabilidade desejada de falha (Pfd). O presente trabalho propõe duas metodologias para o cálculo de VC e T, a primeira baseada em um modelo teórico e a segunda em lógica nebulosa, onde os cálculos e simplificações são feitos considerando uma AIE nível I. / [en] The present work proposes a procedure of Structural Integrity Evaluation (AIE) level I applied to great load structures, it also relares AIE with the Analysis of Risk (AR) using a model of Fuzzy Logic. The calculation of the Residual Life (VC) has been done considering the phenomenons of damages for fatigue, corrosion and fatigue-corrosion. VC is compared to a Deserid Life (VD) wich is obtained of the risk matrix. If VC is smaller than VD, an AIE level II, or a program of substituion of the equipmentis recommended. If VC is larger than VD, a Time of Inspection (T) is determined based on the Analysis of Risk. VD, the minimum acceptable residual life in a great load structure, is determined of an Analysis of Risk. For that, the specialist determine the risk matrix, in which the different risk levels are indicated. For each risk level, it is associated a VD and a deserid probability of flaw (Pfd). The present work proposes two methodologies for the calculation of VC and T. The first based on a theoretical model and the second fuzzy logic, where the calculations and simplifications are made considering an AIE level I.

Wearable sensors and systems have become increasingly popular for diverse applications. An emerging technology for physical activity assessment is Smart Textile Systems (STSs), comprised of sensitive/actuating fiber, yarn, or fabric that can sense an external stimulus. All required components of an STS (sensors, electronics, energy supply, etc.) can be conveniently embedded into a garment, providing a fully textile-based system. Thus, STSs have clear potential utility for measuring health-relevant aspects of human activity, and to do so passively and continuously in diverse environments. For these reasons, STSs have received increasing interest in recent studies. Despite this, however, limited evidence exists to support the implementation of STSs during diverse applications. Our long-term goal was to assess the feasibility and accuracy of using an STS to monitor human activities. Our immediate objective was to investigate the accuracy of an STS in three representative applications with respect to occupational scenarios, healthcare, and activities of daily living. A particular STS was examined, consisting of a smart socks (SSs), using textile pressure sensors, and smart undershirt (SUS), using textile strain sensors. We also explored the relative merits of these two approaches, separately and in combination. Thus, five studies were completed to design and evaluate the usability of the smart undershirt, and investigate the accuracy of implementing an STS in the noted applications. Input from the SUS led to planar angle estimations with errors on the order of 1.3 and 9.4 degrees for the low-back and shoulder, respectively. Overall, individuals preferred wearing a smart textile system over an IMU system and indicated the former as superior in several aspects of usability. In particular, the short-sleeved T-shirt was the most preferred garments for an STS. Results also indicated that the smart shirt and smart socks, both individually and in combination, could detect occupational tasks, abnormal and normal gaits, and activities of daily living with greater than 97% accuracy. Based on our findings, we hope to facilitate future work that more effectively quantifies sedentary periods that may be deleterious to human health, as well as detect activity types that may be help or hinder health and fitness. Such information may be of use to individuals and workers, healthcare providers, and ergonomists. More specifically, further analyses from this investigation could provide strategies for: (a) modifying a sedentary lifestyle or work scenario to a more active one, and (b) helping to more accurately identify occupational injury risk factors associated with human movement. / PHD / The use of interactive or “smart” textiles that have sensing material(s) incorporated into them supports an emerging technology for physical activity assessment called Smart Textile Systems (STSs). STSs are an increasingly useful technology for researchers, athletes, patients, and others. Our aims in the current study were the development and assessment of a new smart undershirt (SUS) that was designed to monitor low-back and shoulder motions, and to evaluate the preferred placement and usability of two STSs. We also assessed the accuracy of two smart garments, smart socks (SSs) and the SUS, both individually and in combination. Accuracy was evaluated in terms of the ability of these systems to distinguish between diverse simulated occupational tasks, normal and abnormal walking patterns, and several typical daily activities. Our investigation indicated that STSs could discriminate between different human activities common in three domains: occupational scenarios, healthcare, and activities of daily life. We also found that both smart garments (i.e., SSs and SUS) provided similar accuracy for activity classification, typically exceeding 97%, and thus there was no clear superiority between these two smart garments. We conclude that, overall, smart garments represent a promising area of research and a potential alternative for discriminating and monitoring a range of human activities. Use of this technology in the future may have positive implications for health promotion.