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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.
41

Byggnadslogistik i infrastrukturprojekt för effektivare användning av grävmaskiner / Logistical Coordination in an Infrastructure Project for Better Utilization of Excavators

Kuronen, Jari, Lundgren, Jonas January 2013 (has links)
Detta examensarbete har utförts på högskoleingenjörsprogrammet för Byggteknik och Design vid Kungliga Tekniska Högskolan i samarbete med Svensk Bygglogistik AB. Arbetet diskuterar betydelsen av byggnadslogistik i ett infrastrukturprojekt för att uppnå en högre utnyttjandegrad för grävmaskiner med stöd av logistiksamordningsverktyg. Sammanlagt har 2150 mätningar utförts under två veckors tid för att kartlägga utnyttjandegraden för en bandgrävare (EC250CL) och en hjulgrävare (Atlas 1505M) på ett referensprojekt i Stockholmsregionen. Resultatet har sammanställts separat för de olika resurserna genom att redovisa och analysera andelen outnyttjad tid och de bakomliggande orsakerna till den outnyttjade tiden. Resultatet visar att utnyttjandegraden för bandgrävaren är 53 % och 59 % för hjulgrävaren vilket tyder på att ett förbättringsutrymme finns. Avslutningsvis diskuteras rekommendationer för hur användning av logistiksamordningsverktyg kan utökas inom anläggningssidan. / This thesis is written as a concluding project at the programme of Constructional Engineering and Design at KTH Royal Institute of Technology in cooperation with Svensk Bygglogistik AB. The thesis discusses the significance of logistical coordination in an infrastructure project in order to achieve a more optimized use for excavators by using logistical planning tools. 2150 measurements have been documented under a two week period at a reference project in the Stockholm region in order to achieve a valid and representable result for the utilization of two different excavators with varied attributes and prerequisites. The results have been summarized separately for each excavator showing the proportion of unutilized time, the proportion of reasons behind unutilized time as well as the relationship between unutilized activity and time.The results show that the utilization rate is 53 % for the excavator of model EC250CL and 59 % for the excavator of model Atlas 1505M. This clearly indicates that there is a span for improvement. As conclusion recommendations are discussed of how to increase awareness and use of logistical planning tools for infrastructure projects.
42

Модернизация механизма открывания днища ковша экскаватора ЭКГ-20, производства ПАО "Уралмашзавод" : магистерская диссертация / Modernization of the mechanism of opening the bottom of the bucket of an excavator EKG-20, produced by PJSC "Uralmashzavod"

Алексеев, И. А., Alekseev, I. A. January 2019 (has links)
Одним из основных видов оборудования для горнодобывающей промышленности является экскаватор. Наиболее крупным производителем данного вида оборудования в Российской федерации является ПАО «Уралмашзавод» г. Екатеринбург. Наиболее распространенным среди используемых экскаваторов является серийный электрический экскаватор ЭКГ-20 с гусеничным ходом и с объемом ковша от 18 до 22 куб.м по международному стандарту SAE J67. На основе собранных статистических данных было проведено исследование эффективности работы экскаватора. Основным критерием, определяющим эффективность экскаватора. В ходе статистического исследования было выявлено, что наибольший процент аварийных простоев, связан с механизмом открывания днища ковша. Объектом данного проекта является электрический одноковшовый карьерный экскаватор ЭКГ-20, производства ПАО «Уралмашзавод». Предметом исследования является механизма открывания днища ковша. Основная цель данной работы является модернизация механизм открывания днища ковша, а также проведение анализа эксплуатационных показателей и экономической целесообразности проведения модернизации. / One of the main types of equipment for the mining industry is an excavator. PJSC "Uralmashzavod". Yekaterinburg. The most common among the types of excavators is a serial electric excavator EKG-20 with a delivery capacity of 18 to 22 cubic meters according to the international standard SAE J67. Based on the collected statistical data, a study was conducted of the efficiency of the excavator. The main criterion for determining the effectiveness of an excavator. In the course of statistical studies, it was found that the largest percentage of emergency downtime is associated with the opening mechanism of the bottom of the bucket. The object of this project is an electric single-bucket mining excavator EKG-20, produced by PJSC "Uralmashzavod". The subject of research is the mechanism of opening the bottom of the bucket. The main goal of this work is to modernize the mechanism for opening carpet days, as well as to analyze the performance indicators and the economic feasibility of modernization.
43

Design of an excavator grip : A pilot study and development of an ergonomic Human-Machine interface for excavators / Design av en joystick för grävmaskiner : En förstudie och utveckling av ett ergonomiskt Människa-maskin-gränssnitt för grävmaskiner

Mörtsell, Hugo January 2022 (has links)
The Excavator industry is developmentally behind many other similar industries. This is, like many parts of these long living machines, true for the controls used to maneuver them. It has few competent control systems that are ergonomic, comfortable, adaptable, durable and intuitive. Existing solutions that fill some of these criteria exist, but the approximate majority of machines in the world lack a good solution and most are equipped with inadequate solutions.  The doctrine of Human centered design was applied throughout the pilot study to increase the quality of research and ease finding correlations between instances of information. International standards, Human-machine systems and Anthropometrics were consulted to achieve a result adapted for a larger variety of operators.  This thesis consists of the pilot study and prototype development of one such Human-machine-system, more specifically the joystick, or grip as it’s called within the industry. The solution developed is specifically equipped with controls adapted for tiltrotator control. As the grip is developed on behalf of the company engcon, who develops tiltrotators and also the control system including a grip, to offer a complete plug and play solution.  The first main objective was performing a pilot study of what is required in the future for excavator grips. Primarily through interviews with excavator operators, but also a benchmarking and a workshop it was determined what must be achieved in terms of technical and ergonomic solutions.  The second main objective during the thesis was to create a prototype that achieve a high level in terms of grip form. A form which is comfortable to hold, ergonomic to operate for multiple hours and that is adapted to a larger variety of hand sizes than the competitors. It also required a higher level of stability than the current solution. This shape needed to take internal electronics, ISO-standards and future controls into account. The solution must eventually achieve a high level of manufacturability, of which the groundwork was laid during the thesis, but took lower priority. Further testing is required but results so far seem to point towards this being achieved.  This will hopefully post-thesis result in a solution that leads to healthier operators, further enabling female operators entering the field, performing work with higher accuracy and a longer lasting more sustainable product that is intuitive and easy to learn. / Grävmaskinsindustrin ligger utvecklingsmässigt bakom många andra liknande industrier. Detta är, som många delar av dessa långlivade maskiner, sant för kontrollerna som används för att manövrera dem. Den har få kompetenta kontrollsystem som är ergonomiska, bekväma, anpassningsbara, slitstarka och intuitiva. Befintliga lösningar som fyller några av dessa kriterier finns, men approximativt saknar majoriteten av maskiner i världen en bra lösning och de flesta är utrustade med otillräckliga lösningar.  Läran om Människocentrerad design tillämpades genom hela förstudien för att öka kvaliteten på forskningen samt förenkla sökandet av samband mellan instanser av information. Internationella standarder, Människa-maskin-system och antropometri konsulterades för att uppnå ett resultat anpassat för ett större antal operatörer.  Detta examensarbete består av en förstudie och prototyputveckling av ett sådant Människa-maskin-system, närmare bestämt joysticken, eller på engelska grip som är ett vanligare namn inom branschen. Den framtagna lösningen är speciellt utrustad med reglage anpassade för tiltrotatorstyrning eftersom greppet är utvecklat på uppdrag av företaget engcon. Företaget utvecklar huvudsakligen tiltrotatorer men även ett styrsystem inklusive en joystick, för att erbjuda en komplett plug and play-lösning.  Det första huvudmålet var att göra en förstudie av vad som krävs i framtiden av grävmaskinsjoysticks. Främst genom intervjuer med grävmaskinister, men också genom en benchmarking och en workshop, fastställdes vad som måste uppnås vad gäller tekniska och ergonomiska områden.  Det andra huvudmålet under examensarbetet var att skapa en prototyp som uppnår en hög nivå vad gäller greppform. En form som är bekväm att hålla i, ergonomisk att använda i flera timmar och som är anpassad till en större variation av handstorlekar än konkurrenterna. Det krävde också en högre stabilitet än den nuvarande lösningen. Denna form behövde ta hänsyn till intern elektronik, ISO-standarder och framtida reglage. Lösningen måste så småningom uppnå en hög grad av tillverkningsbarhet, vilket grunden lades under examensarbetet, men prioriterades lägre. Ytterligare tester krävs, men resultaten hittills tycks peka mot att detta uppnås.  Detta kommer förhoppningsvis, efter examensarbetet, att resultera i en lösning som leder till hälsosammare operatörer, som ytterligare möjliggör kvinnliga operatörer, ett arbete som kan utföras med högre precision samt en slitstarkare och hållbarare produkt som är intuitiv och lätt att lära sig.
44

An efficient haptic interface for a variable displacement pump controlled excavator

Elton, Mark David 05 1900 (has links)
Human-machine interfaces influence both operator effectiveness and machine efficiency. Further immersion of the operator into the machine’s working environment gives the operator a better feel for the status of the machine and its working conditions. With this knowledge, operators can more efficiently control machines. The use of multi-modal HMIs involving haptics, sound, and visual feedback can immerse the operator into the machine’s environment and provide assistive clues about the state of the machine. This thesis develops a realistic excavator model that mimics a mini-excavator’s dynamics and soil interaction during digging tasks. A realistic graphical interface is written that exceeds the quality of current academic simulators. The graphical interface and new HMI are placed together with a model of the excavator’s mechanical and hydraulic dynamics into an operator workstation. Two coordinated control schemes are developed on an haptic display for a mini-excavator and preliminary tests are run to measure increases in operator effectiveness and machine efficiency.
45

Technologické ověření rýpadel v oblasti zemních prací. / Technology verification excavators in earthworks

FIKOTOVÁ, Petra January 2013 (has links)
This thesis on the topic of Technology verification in the field of wheel excavators and its excavations in the first general part deals with the analysis of the work carried out on the construction site. Wheel excavator analysis tools have been developed and used. The study included ?wheel excavators and the technical parameters and analysis with the binding on the size category of wheel excavators?. The second part of the work deals with the evaluation of the results of the data collection for the determination of the actual times of working wheel excavators; and resultant cycles, depending on the work carried out. In addition, there are factors that affect the intended performance wheel excavators and how it works in the implementation of specific operations. Part of the work is the determination of the values of the correction coefficients for the calculation of the actual performance and the determination of the actual wheel excavators, and subsequent analysis of the excavators? performance dependent upon carried out working operations. In conclusion, on the results gained from the analytical process, proposals and guidelines for the optimal use of wheel excavators within the construction industry have been attained.
46

Návrh optimálního složení mechanizačních prostředků pro pravidelný cyklus údržby staveb k vodohospodářským melioracím pozemků. / Proposal of optimum composition of the mechanization devices for the regular cycle maintenance of building for the wateragricultural meliorations of pieces of land

KRATOCHVÍLOVÁ, Miroslava January 2008 (has links)
In my diploma work I engage in the mechanization for the regular maintenance of building for the wateragricultural meliorations of piece of lands. The applicable mechanization: Dampr, Skrejpr, Dozer, graftmachine, bushescut{\dots}{\dots}{\dots}{\dots}{\dots} My proper work I engage on revitalization of pond names Hamerníků Doubí near by the village Lásenice. Out of the results of my proper work is evident, that the revitalization of ponds is very exacting and expensive work.
47

Velikostně rozlišený atmosférický aerosol v pracovním prostředí povrchového hnědouhelného dolu / Size segregated atmospheric aerosol in selected workspaces of coal strip mine

Basslerová, Barbora January 2017 (has links)
The workers are exposed to aerosol particles in a coal strip mine. These particles are usually generated by the Bucket-wheel excavators which break the mined rock. The goal of the thesis thesis was to compare the concentrations of atmospheric aerosol particles - PM on the Bucket-wheel excavator Schrs 1320, the Stacker ZPDH 6300 and the Bucket- wheel excavator K 800/N2 in the coal quarry Doly Nástup Tušimice, and then to answer the questions what is the main cause of increased concentration PMx and whether the mining machines are different from each other. The measurement was realized stepwise on every mining machine in the time period from 12. 8. to 2. 9. 2016. The concentrations of PM1, PM2,5 and PM10 were measured by two portable laser nephelometers in the cab drivers and the outdoor walkway of the mining machines with the integration time of 1 minute. The air temperature and the relative humidity were monitored in both types of settings in every five minutes. The PMx concentrations variability is usually determined by the type of work and by the type of smoking. Consequently, PM concentrations on the mining machines were compared at the morning exchanges and evening exchanges, during the outdoor cleaning by sweeping, the indoor cleaning by hoovering and during the smoking. The highest...
48

Řízení hydraulických rozváděčů miniexkavátoru / Control of hydraulic directional valves of mini excavator

Nožka, Michal January 2018 (has links)
This diploma thesis deals with the design of control algorithm for hydraulic directional control valves of a zero-emission mini excavator. Zero emission excavator have same parameters as diesel engine powered version of it. To solve this problem simulations were done for hydraulics and control algorithm of this machine. To find right parameters of simulation models, experiments have been done. There were also proposed some methods to obtain the right set of parameters. The result of this diploma thesis is control algorithm for directional control valves of this very unique mini excavator that doesn't have any competitor (in terms of control algorithm). Set of parameters was also tested during experiments.
49

Modely a simulace pochodů bezemisního mini-exkavátoru s elektrickým pohonem / Models and simulations of the emission-free mini-excavator with electric drive

Matiaško, Dušan January 2021 (has links)
The diploma thesis dealt with a partial problem of conversion of the mini-excavator E19 by Bobcat with an internal combustion engine to emission-free propulsion. The main task was design and construction of electrical and hydraulic circuits focusing on the drive of a mini-excavator. The simulations verified the properties and behavior of the mini-excavator under different conditions and initial settings. The results were comfirmed by experimental measurements. The output of the simulations recommended adjustments to the values of individual parameters depending on the travel speed but also the efficiency of the entire machine.
50

Analýza namáhání vybraných konstrukčních částí bagru při provozu / Analysis of mechanical loads of selected structural parts of the excavator during operation

Busta, Michal January 2021 (has links)
This thesis is focused on the issue of computational modeling of soil harvesting while using the compact excavator from the company DOOSAN BOBCAT EMEA s.r.o.. The solution consists in creating two computational models in Rocky DEM and Ansys Mechanical. Rocky DEM software is used to solve the disconnection of soil by excavator components using the discrete element method. The outcome includes courses of forces and moments during the particular time of the individual joints of the model that was used. The obtained courses are then applied as an external load to the joint of a selected structural part of the analyzed model using a kinematic model in ANSYS Mechanical. The kinematic model consists of simplified geometry models of individual parts of the excavator arm, and a more detailed geometry model of the analyzed part of the arm. All the parts are connected to each other by rotational bonds representing joints. A static structural analysis of the mechanical stress is performed in ANSYS Mechanical for the prepared model during the simulated process. Finally, the selected structural part is assessed with respect to the elastic limit and fatigue strength.

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