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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

The Automated Laser Position System - ALPS

Lundberg, Eric J. 01 August 2012 (has links)
The construction industry needs an accurate real-time positioning system. Such a system, if successfully implemented, would lead to significant increases in the performance of many construction operations. This thesis presents the Automated Laser Position System (ALPS) for accurate real-time positioning. ALPS is a spin-off of the Automated Position And Control System (APAC) research, sponsored by the National Science Foundation under grant DMC-8717476. The ALPS concept has three primary components: a rotation laser, laser detectors and a central processing unit. ALPS generates both horizontal (X,Y) and vertical (Z) position information. It is mathematically predicted that ALPS could produce accuracies of ± 17 mm in the horizontal and ± 5,9 mm in the vertical, at a range of 400 m. Position measurements would be updated 50 times a second. / Master of Science
92

Desenvolvimento de um sistema de apoio à decisÃo na seleÃÃo de motoniveladoras para a execuÃÃo de obras de terraplenagem e de pavimentaÃÃo / Development of a system for decision support in the selection of motor graders to perform earthwork and paving

Maria Edjane da Silva Soares 12 May 2015 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A velocidade de concepÃÃo e de execuÃÃo das infraestruturas tem aumentado devido à utilizaÃÃo de softwares e equipamentos eficientes, o que tem exigido um melhor desempenho de cada etapa. No entanto, apesar dos custos envolvidos com equipamentos serem os itens de maior peso na construÃÃo rodoviÃria, poucos sÃo os sistemas existentes de apoio à decisÃo para a seleÃÃo das frotas. Propostas de seleÃÃo de frotas tÃm sido elaboradas por pesquisadores no Brasil e no mundo, porÃm a maioria consideram apenas caminhÃes e escavadeiras/carregadeiras ou scrapers. Este trabalho tem como objetivo desenvolver um sistema de apoio à decisÃo na seleÃÃo de motoniveladoras para a execuÃÃo de obras de terraplenagem e de pavimentaÃÃo, denominado SADPATROL. Inicialmente, foi feita uma anÃlise da evoluÃÃo tecnolÃgica do equipamento motoniveladora visando verificar a influÃncia destas melhorias sobre o aumento da produtividade. Foram analisadas as equaÃÃes existentes na literatura para o cÃlculo de produtividade e apÃs verificada a representatividade da equaÃÃo utilizada no paÃs esta foi escolhida para compor o SADPATROL, com as devidas alteraÃÃes em suas variÃveis. AtravÃs da anÃlise de cada variÃvel da equaÃÃo foi possÃvel identificar o quanto as mesmas influenciavam no resultado da produÃÃo desta forma, foram implementadas melhorias, como a inserÃÃo de valores padrÃes para as variÃveis do sistema, permitindo a obtenÃÃo de resultados mais precisos, caso o usuÃrio nÃo possua dados medidos em campo. O SADPATROL possui cadastrado em seu banco de dados 46 tipos de motoniveladoras, dos mais variados modelos e tamanhos, de 12 fabricantes distintos. à possibilitado ao usuÃrio calcular a frota com equipamentos prÃprios e verificar se esta atende ao prazo da obra. Caso o prazo nÃo seja atendido pela frota prÃpria ou o usuÃrio nÃo possua equipamentos, o sistema executa as informaÃÃes da obra para todos os equipamentos do banco de dados e fornece a soluÃÃo com as 46 opÃÃes organizadas em frotas, em ordem crescente de quantidade de equipamento. à possibilitado ainda selecionar os equipamentos nos quais se possui informaÃÃo de custo horÃrio, para assim obter a frota de menor custo. Toda a multiplicidade de informaÃÃes necessÃrias à seleÃÃo de motoniveladoras, e suas inter-relaÃÃes e dependÃncias, foram organizadas de forma sistÃmica no software SADPATROL, diminuindo assim o empirismo e a dependÃncia da experiÃncia humana na seleÃÃo de frotas. A presente pesquisa pode ainda contribuir para auxiliar a elaboraÃÃo de normas tÃcnicas e para a disseminaÃÃo do conhecimento sobre o referido equipamento. / The demands on speed and efficiency of infrastructure design and construction has increased due to the use of software and more productive equipment, which has required better performance of equipment planners at each step. However, even considering that the costs associated with equipment are one of the items with the greatest weight in road construction, there are few computerized systems for fleet selection decision support. Fleet selection systems have been developed by researchers in Brazil and worldwide, but most of them consider only trucks and excavators/loaders or scrapers. This research aims at developing a decision support system for the selection of motor graders for construction activities involving earthmoving and paving works named SADPATROL. Initially, an analysis of the motor grader technological evolution was performed in order to evaluate the influence of the improvements on productivity gains. The equations presented in the literature were studied for productivity calculation and, after verifying the suitability of the equation, the equation was incorporated in the SADPATROL system with the necessary changes in its variables. Through the analysis of the variables in the equation, it was possible to identify how they influenced the productivity. Through this analysis, improvements were implemented. These improvements consisted of the inclusion of standard values for the system variables, allowing the achievement of more accurate results if the user has no data for productivity measured in the field. The SADPATROL system has 46 types of motor graders included in its database, from many different models and sizes and from 12 different manufacturers. The user is able to plan the fleet with its own equipment and verify if it satisfies the construction project deadline. If the deadline cannot be satisfied using the available fleet or the user has no equipment, the system performs the construction planning using all database equipment and provides the optimal solution with 46 options organized into fleets in increasing order according to the amount of equipment needed. It is also possible for the user to select the equipment using time cost information and, thus, achieve the lowest cost fleet. The significant amount of information necessary for motor graders selection and its inter-relationships and dependencies were organized in a systematic way in the SADPATROL system, reducing, the empiricism and the dependence on human expertise in selecting fleets. This research may also help in assisting in the development of technical standards and expanding the dissemination of knowledge about such equipment.
93

A Study of Microwave curing of Underfill using Open and Closed microwave ovens

Thakare, Aditya 14 April 2015 (has links)
As the demand for microprocessors is increasing with more and more consumers using integrated circuits in their daily life, the demand on the industry is increasing to ramp up production. In order to speed up the manufacturing processes, new and novel approaches are trying to change certain aspects of it. Microwaves have been tried as an alternative to conventional ovens in the curing of the polymers used as underfills and encapsulants in integrated circuits packages. Microwaves however being electromagnetic waves have non uniform energy distribution in different settings, causing burning or incomplete cure of polymers. In this study, we compare the two main types of microwaves proposed to perform the task of curing the polymers. To limit the study and obtain comparable results, both microwaves were limited to propagate in a single mode, TE10. The first is a closed microwave cavity using air as the propagation medium, and the second is an open microwave oven with a PTFE cavity that uses an evanescent field to provide energy. The open air cavity was studied with different orientations of a substrate placed inside it so as to find the best case scenario in the curing process. This scenario was then compared with the best case scenario found for a sample cured in an evanescent field. This comparison yielded results showing an advantage of the open microwave in maximum field present, thus leading to higher localized energy absorption and temperatures in the substrate, however this case also lead to a higher temperature gradient. The substrate cured in the closed microwave has a lower temperature gradient, but also a lower maximum field which leads to slower cure. In the TE10 mode therefore, a closed microwave has an overall advantage as the heating process is only slightly slower than that of an open cavity, but the temperature gradient in this case is significantly lower.
94

Operator and Machine Models for Dynamic Simulation of Construction Machinery

Filla, Reno January 2005 (has links)
<p>VIRTUAL PROTOTYPING has been generally adopted in product development in order to minimise the traditional reliance on testing of physical prototypes. It thus constitutes a major step towards solving the conflict of actual increasing development cost and time due to increasing customer demands on one side, and the need to decrease development cost and time due to increasing competition on the other. Particularly challenging for the off-road equipment industry is that its products, working machines, are complex in architecture. Tightly coupled, non-linear sub-systems of different technical domains make prediction and optimisation of the complete system’s dynamic behaviour difficult.</p><p>Furthermore, in working machines the human operator is essential for the performance of the total system. Properties such as productivity, fuel efficiency, and operability are all not only dependent on inherent machine properties and working place conditions, but also on how the operator uses the machine. This is an aspect that is traditionally neglected in dynamic simulations, because the modelling needs to be extended beyond the technical system.</p><p>The research presented in this thesis focuses on wheel loaders, which are representative for working machines. The technical system and the influence of the human operator is analysed, and so-called short loading cycles are described in depth. Two approaches to rule-based simulation models of a wheel loader operator are presented and used in simulations. Both operator models control the machine model by means of engine throttle, lift and tilt lever, steering wheel, and brake only – just as a human operator does. Also, only signals that a human operator can sense are used in the models. It is demonstrated that both operator models are able to adapt to basic variations in workplace setup and machine capability. Thus, a “human element” can be introduced into dynamic simulation of working machines, giving more relevant answers with respect to operator-influenced complete-machine properties such as productivity, fuel efficiency, and operability already in the concept phase of the product development process.</p> / ISRN/Report code: LiU-Tek-Lic 2005:44
95

Factors for maintaining successful business partnerships : A case study of the construction equipment industry

Atzmüller, Albin, Kamande, Sylvia, Sundblad, Michael January 2011 (has links)
As organisations try to emerge from the recent economic downturn, they attempt to enter different markets to decrease their dependency on their core market. Due to high costs in R&amp;D and the risk of failure, organisations try to sell the core components of their products to business partners who can incorporate these components into their own offering. Using a qualitative research method, we studied the case of TACHI as a player in the construction equipment industry. The purpose of the research was to find factors for maintaining successful business partnerships within this industry and also the role of co- branding in these business partnerships. After analysing the results of our study and reflecting on the theoretical framework, we concluded that operational compatibility, and commitment and trust were considered as the key factors that were most important in making business partnerships work successfully. Interestingly, players in the construction equipment industry do not consider co-branding as a strategy for entering new markets. However, we discovered a new phenomenon, which is informal branding, and we recommend this as a topic for future research.
96

Quantifying Operability of Working Machines

Filla, Reno January 2011 (has links)
In working machines the human operator is essential for the performance of the total system. Productivity and energy efficiency are both dependent not only on inherent machine properties and working place conditions, but also on how the operator manoeuvres the machine. In order to operate energy-efficient the operator has to experience the machine as harmonic. This is important to consider during the development of such working machines. It is necessary to quantify operability and to include this interaction between the human operator and the machine in both the later stages of a development project (where physical prototypes are evaluated by professional test operators) as well as in the earlier stages like concept design (where only virtual prototypes are available). The influence of the human operator is an aspect that is traditionally neglected in dynamic simulations conducted in concept design, because the modelling needs to be extended beyond the technical system. The research presented in this thesis shows two approaches to rule-based simulation models of a wheel loader operator. Both operator models interact with the machine model just as a human operator does with the actual machine. It is demonstrated that both operator models are able to adapt to basic variations in workplace setup and machine capability. A “human element” can thus be introduced into dynamic simulations of working machines, providing more relevant answers with respect to operator-influenced complete-machine properties such as productivity and energy efficiency. While the influence of the human operator is traditionally ignored when evaluating machine properties in the early stages of the product development process, later stages are very reliant on professional test operators using physical prototypes. The presented research demonstrates how the traditional subjective evaluation of a machine’s operability can be complemented by a calculated measure for the operator’s control effort, derived from the recorded control commands of the machine operator. This control effort measure can also be calculated from the control commands of an operator model in a simulation, such as those presented in this thesis. It thus also allows for an assessment of operability already in the concept design phase. In addition, the results of a study of quantifying operator workload by means of measuring psycho-physiological data such as heart rate variability and respiration rate are presented as the first step towards realising workload-adaptive operator assistance functions. Once fully developed, the method itself can also be used as another complement to the traditional subjective evaluations of operability. This approach can then be applied not only in testing of physical prototypes, but also earlier in the product development process in studies on human-in-the-loop simulators. / I arbetsmaskiner spelar föraren en avgörande roll för maskinens prestanda. Såväl produktivitet som energieffektivitet beror inte enbart av maskinens egenskaper och arbetsomgivningen, utan beror också av sättet på vilket föraren manövrerar maskinen. För att främja ett bränslesnålt körsätt ska maskinerna upplevas som harmoniska och det är viktigt att beakta detta vid utvecklingen. Det är nödvändigt att kvantifiera maskinharmonin och att ta hänsyn till interaktionen mellan föraren och maskinen i alla steg av ett utvecklingsprojekt. Detta gäller såväl sena faser, när fysiska prototyper redan har tagits fram och utvärderas av professionella provförare, såväl som tidiga faser som konceptutveckling, när endast virtuella prototyper finns tillgängliga. Förarens inflytande beaktas traditionellt inte i prestandasimuleringar i konceptfasen, eftersom detta innebär att mer än enbart det tekniska systemet måste modelleras. I den forskningen som presenteras här visas två olika regelbaserade modeller av hjullastarförare. Båda förarmodellerna använder maskinmodellen på samma sätt som en verklig förare använder en verklig maskin. Det visas att båda förarmodellerna kan anpassa sig till förändringar både i arbetsomgivningen och i maskinens egenskaper. I och med detta kan man utöka dynamiska simuleringar av arbetsmaskiner med ”ett mänskligt element”. Detta ger bättre resultat vad gäller produktivitet, energieffektivitet och liknande egenskaper som föraren påverkar i kompletta maskiner. Medan man i tidiga faser av produktutvecklingsprocessen traditionellt bortser från förarens inflytande, så är man i senare faser mycket beroende av att professionella provförare testar fysiska prototyper. Den här presenterade forskningen visar hur den traditionella subjektiva förarbedömningen av en maskins körbarhet kan kompletteras med ett mått på förarens ”spakarbete”, som beräknas utifrån en mätning på hur föraren använder sina kontroller för att styra maskinen. Detta mått på ”spakarbete” kan också beräknas utifrån de spaksignaler som genereras av förarmodellerna i en simulering. I och med detta kan en maskins körbarhet undersökas redan under konceptutvecklingen. I avhandlingen redovisas också resultaten från en studie som gjorts i syfte att kvantifiera förarens arbetsbelastning genom att mäta psykofysiologiska mått som variationer i hjärtfrekvens och andningsfrekvens. Studien är ett första steg mot att förverkliga en vision av stödfunktioner i arbetsmaskiner vilka anpassar sig efter förarens momentana arbetsbelastning. En sådan metod att mäta förarens arbetsbelastning kan också användas som ett komplement till den traditionella subjektiva förarbedömningen av en maskins körbarhet. Metoden kan inte bara användas vid provning av fysiska prototyper utan också tidigare i produktutvecklingsprocessen vid studier i avancerade körsimulatorer. / IN ARBETSMASCHINEN spielt der Fahrer eine entscheidende Rolle für die Leistung des gesamten Systems. Produktivität und Energieeffizienz sind nicht nur abhängig von den Grundeigenschaften der Maschine und den Bedingungen am Einsatzort, sondern auch von der Art und Weise wie der Fahrer die Maschine manövreriert. Für eine kraftstoffsparende Fahrweise muss der Fahrer die Maschine als harmonisch erleben. Dies muss bei der Entwicklung beachtet werden. Das Erfassen der Fahrbarkeit und die Berücksichtigung des Zusammenspiels zwischen Fahrer und Maschine ist in allen Phasen der Entwicklung notwendig, sowohl in den späteren Phasen, wenn Prototypen von Erprobungsfahrern ausgewertet werden, als auch in den frühen Phasen wie dem Konzeptentwurf, wenn nur virtuelle Prototypen vorhanden sind. Der Fahrereinfluss wird traditionell in den dynamischen Simulationen während des Konzeptentwurfs vernachlässigt, denn er erfordert die Ausweitung der Modellierung über das technische System hinaus. In dieser Dissertation werden zwei Herangehensweisen zur Erstellung regelbasierter Modelle eines Radladerfahrers aufgezeigt. Beide Fahrermodelle interagieren mit dem Maschinenmodell gleich einem menschlichen Fahrer mit einer realen Maschine. Es wird gezeigt, dass beide Fahrermodelle in der Lage sind, sich auf Änderungen des Einsatzortes und der Maschineneigenschaften anzupassen. Somit kann „ein menschliches Element“ in die dynamische Simulation von Arbeitsmaschinen eingeführt werden, was zu qualitativ besseren Resultaten bezüglich Produktivität, Energieeffizienz und ähnlicher fahrerbeeinflusster Eigenschaften führt. Während man in den frühen Phasen der Produktentwicklung traditionell vom Fahrereinfluss absieht, ist man später sehr auf die Erprobung physischer Prototypmaschinen durch professionelle Testfahrer angewiesen. In dieser Dissertation wird aufgezeigt, wie die traditionell subjektive Bewertung der Fahrbarkeit einer Maschine mit einem Maß der „Steuerungsarbeit“ komplettiert werden kann, berechnet aus der gemessenen Betätigung der dem Fahrer zur Verfügung stehenden Bedienelemente. Dieses Maß der „Steuerungsarbeit“ kann auch aus den Signalen der von uns vorgestellten Fahrermodelle in einer Simulation berechnet werden. Damit kann man die Fahrbarkeit bereits in der Konzeptentwicklung abschätzen. Weiterhin werden die Resultate einer Studie zur Quantifizierung der Fahrerbelastung mithilfe psychophysiologischer Daten wie Veränderungen der Herzfrequenz und Atmungsfrequenz vorgestellt. Diese Studie ist ein erster Schritt zur Entwicklung eines Assistenzsystemes, dass sich an die aktuelle Fahrerbelastung anpasst. Eine solche Messmethode der Fahrerbelastung kan auch zusätzlich zur traditionellen subjektiven Fahrbarkeitseinschätzung angewendet werden – nicht nur bei der Erprobung physischer Prototpyen, sondern auch schon frühzeitig bei Studien auf Fahrsimulatoren.
97

An Electro-Hydraulic Traction Control System for Heavy Duty Off-Road Vehicles: Formulation and Implementation

Addison B. Alexander (5929460) 16 January 2020 (has links)
<div>Traction control (TC) systems have become quite common in on-road passenger vehicles in recent years. However, for vehicles in other applications, they are not as widely available.</div><div>This work presents a methodology for the proper design and implementation of a traction control system for heavy duty off-road machines, using a wheel loader as a reference vehicle.</div><div><br></div><div><div>A simulation model was developed, using standard vehicle dynamics constructs, including equations of motion and a description of the distribution of weight between the axles for different operating conditions. This model contains considerations for resistive forces acting on the machine implement, such as that generated by a work pile. The simulation also incorporates a detailed representation of the slip-friction characteristics between the vehicle tires and the road surface. One objective of this research was to model this interaction accurately, because the system traction behavior is dependent on it. Therefore, a series of tests was run using a state estimator to generate data on the slip-friction relationship at various ground conditions, and the results were incorporated into the simulation model. The dynamics of the machine braking system pressure were also modeled to give a more accurate description of the system response. The result is a mathematical model capable of accurately reproducing the behavior of the real-world system.</div></div><div><br></div><div><div>One of the primary goals of this work was the description of the traction control strategy itself, which should work as effectively and efficiently as possible. Several different aspects of the system were taken into consideration in generating this control structure. First, a relatively simple controller based on a PID control law was created. This controller was updated to account for peculiarities of the traction control system, as well as aspects like time delay. From there, more advanced controllers were created to address certain aspects of the system in greater detail. First, a self-tuning controller based on real-time optimization strategies was developed, to allow the controller to quickly adapt to changes in ground condition. Then, different nonlinear controllers were synthesized which were designed to address the theoretical behavior of the system. All of these controllers were simulated using the system model and then some were run in experiments to show their potential for improving system performance. To improve system efficiency, the machine drivetrain itself was also examined to develop a more efficient control algorithm. By designing a more efficient methodology, traction control congurations which had previously seen increases in fuel consumption of 16% were now able to actually reduce fuel usage by 2.6%.</div></div><div><br></div><div><div>Another main goal of this work was the development of a prototype system capable of implementing the formulated control strategies. The reference machine was modied so that the brakes could be controlled electronically and independently for implementation of the TC system. The vehicle was instrumented using a wide array of sensors, and estimation methodologies for accurately determining vehicle speed and implement forces were designed. The velocity estimator designed in this work is more accurate and more reliable than an industry standard sensor, which is important for traction control implementation. The implement force estimate was also quite accurate, achieving payload estimate errors of less than 2.5%, comparable to commercially-available measurement systems. This setup allowed for tests to be accurately compared, to assess the traction control performance.</div></div><div><br></div><div><div>With the objective of performing experiments on the traction control system, many tests were run to assess its capabilities in various situations. These tests included experiments for characterizing the vehicle behavior so that the simulation model could be updated to accurately reflect the physical machine performance. Another task for the experimental work was the generation of useful metrics for quantifying traction control performance. Laboratory experiments which were very controlled and repeatable were also run for generating data to improve the system model and for comparing traction control performance results side-byside. The test metrics proposed for these experiments provided for accurate, repeatable comparisons of pushing force, tire wear, and brake consumption. For each of these tests, the traction control system saw an increase in pushing force of at least 10% when compared with the stock machine, with certain operating conditions showing increases as high as 60%. Furthermore, every test case showed a decrease in wheel slip of at least 45% (up to 73% for some cases), which translates into increased tire longevity.</div></div><div><br></div><div><div>Other tests were conducted in the eld, designed to mimic the real-world operating conditions of the wheel loader. Various performance comparisons were made for different congurations in which traction control could provide potential benets. These included parameters for comparing overall vehicle performance in a typical truck loading cycle, such as tire wear, fuel consumption, and material moved per load. Initial results for this testing showed a positive result in terms of wheel slip reduction, but other performance parameters such as fuel consumption were negatively impacted. Therefore, the control structure was reexamined extensively and new methods were added to improve those results. The final control implementation saw a 12% reduction in tire slip, while also reducing fuel consumption by 2.6% compared to the stock system. These results show signicant potential for traction control as a technology for maximizing the performance output of construction machines.</div></div>
98

Environmental management in China

Karlsson, Victoria January 2010 (has links)
In this study the aim was to investigate and nuance how the Volvo Construction Equipment (VCE) production Hub can evolve their environmental work, at Chinese wheel loader producer Shandong Lingong (SDLG), to reach Volvo standard. The study also aimed to investigate what international companies in China should take into consideration in their environmental work. The work was carried out by answering the following research questions; In which way or ways can the VCE Hub at SDLG evolve their environmental work to reach Volvo standard? What should international companies take into consideration in their environmental work when establishing on the Chinese market, and why? A lot of the information in this Thesis is based on empirical data, i.e. interviews. Three interviews with Swedish companies have been carried out. They are all highly valuing Environmental work but use different methods, their situations are unlike and they produce diverse products. Several interviews with people working with environmental issues in different ways have also been done, as well as with the SGS; a Chinese certification body. Three different companies with production in or around Shanghai were chosen; Volvo CE, SKF, and Sandvik. All three companies are originally Swedish but with production in China. Environmental work is highly prioritized in Sweden and the companies have global environmental policies and goals. The three companies were chosen because they are in different production areas but they are striving in the same direction with environmental issues in China. They are working differently and their situations are of various kinds. In 2006 Volvo CE invested in a Chinese wheel loader producer named Shandong Lingong. Volvo CE has a Hub, at the plant, which runs independently. SDLG are still not ISO 14001 certified and do not have an environmental management system (EMS) that is conformably with the Volvo demands. The most important to take into consideration when doing business in China is according to the study; top management support, to do training for the employees, mediate the importance of awareness, and to have knowledge about Chinese regulations. These are some of the issues International companies have to deal with when doing business in China. A well established EMS is a necessity for a good environmental work. To implement an EMS in the Hub as a pilot project is the best solution according to the information gathered in this thesis. SDLG could be a part-, they can evaluate-, and later it could be possible to implement the process in the whole SDLG. Due to this methodology they will learn how to work according to Volvo requirements and obtain benefits of an implementation. There are three different alternatives for the ISO 14001 certification of the Hub according to this work. For the Hub to be ISO 14001 certified together with another Volvo plant seems to be the best alternative thought it reduces the amount of work with legal authorities. VCE’s EMS will also not be compared with SDLG and it will be moneysaving. The policies and Environmental aspects (EA) though have to be rewritten to be suitable for both the factories.
99

Modular Communications Relay for Autonomous Quarry Operation

Knutsson, Simon, Larmark, Daniel January 2018 (has links)
Today’s quarries face a change in the operational processes, where the development of automated transport systems and machines have intensified the necessity for reliable and stable data transfer. Within the dynamic environment, with piles building up suddenly, frequently changing mining faces due to blasting, as well as a frequently changing general environment that affect the network coverage negatively, there is a need for a solution that can adapt to the changing environment. The aim of this research has been to investigate the requirements for a dynamic infrastructure, and develop a platform based on today’s available technical solution components that can act as a dynamic platform for the evolving autonomous quarry. This by also reducing the time the worker is exposed to the harsh environment that the quarry presents. The research was conducted through a combination of a product development strategy and Design Research Methodology to develop a concept that fulfills the customer needs that are identified. An iterative process, where the needs were translated in to prototypes, has created learnings through every step of the development process. The result is a relocatable platform for communications relay, which is mounted on a trailer with a fixed mast to distribute short-wave communications in the area where the mobile unit is needed. The trailer is equipped with a four-point leveling system that also act as a stabilization system for the unit and ensures that the platform maintains a horizontal plane at all times. This platform is a first step towards a fully autonomous management of the communication infrastructure which in the future will be needed when a stable process and connection is necessary in the frequently changing environment. The relocatable platform is a necessity for adaption of the short-wave communication in the constantly changing environment. Since this is a first iteration and concept in the development of a dynamic platform, extensive field tests are required to determine which subcomponents are in need of further development or optimization. The completed prototype for the platform is functional and field ready for further testing in its real environment for further collecting of data points. This concept is a subcomponent of a larger system, where the goal is to increase the productivity and reduce the environmental impact from today’s quarry industry. Through reduction of human interaction and management of the relocation of the mobile unit, the workers safety is increased and the harsh environmental exposure is reduced.
100

Water emissions from fuel cell-powered construction equipment : Quantifying liquid water and water vapor emissions for sustainable construction equipment

Bulut, Roni, Söderberg, Patric January 2023 (has links)
The construction sector is responsible for 20% of Greenhouse Gas (GHG) emissions, of whichdiesel-powered construction equipment are large contributors. Currently there are many ongoing Fuel Cell (FC) powered construction equipment projects as it is seen as an attractiveoption to power the futures zero-emission heavy-duty machines. Although an attractivealternative, hydrogen FC has drawbacks such as releasing liquid water and water vapor viathe exhaust as a byproduct which in their working environment can cause a suite of issues. Agap in the literature on the water exhausted is present and therefore this degree project seeksto investigate the amount, and ratio, of liquid water and water vapor released from threetypical construction equipment drive cycles which would allow further investigation onappropriate management. The method used for this degree project was to modify a pre-mademodel in Simulink built with Simscape blocks. The model was modified to represent a FCsystem used in a test-rig by implementing experimental and measured data for design andoperating parameters. Different pressures, temperatures, and cathode inlet RelativeHumidity (RH) were investigated to find their effect on the performance and water in theexhaust. A sensitivity analysis of different unknown parameters was also conducted tounderstand their influence on the results. For the reference case, the results showed that foran articulated hauler, the water in the exhaust was 26% liquid which translates to 8.6 kg for a1-hour drive cycle. The crawler excavator and wheel loader, both had 30-minute drive cyclesand had 1.1 kg liquid water with a liquid water ratio of 7% and 0.7 kg liquid water with aliquid water ratio of 5% in the exhaust respectively. For a full 8-hour workday with twoparallel FCs connected, the articulated hauler liquid water amount is 137.6 kg, the crawlerexcavator 35.2 kg, and the wheel loader 22.4 kg. Overall, it was found the liquid water ratiocould be changed to a large extent with different operating parameters, where thetemperature had the greatest influence. The system and stack efficiencies did not changeconsiderably with different operating parameters, meaning that the total water in the exhaustremained similar for the different respective drive cycles.

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