• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 13
  • 12
  • 12
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 60
  • 15
  • 8
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 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.
21

Hodnocení sklízecích mlátiček JOHN DEERE 9880 a NEW HOLLAND CR 9080 při sklizni obilovin a ozimé řepky. / Rating combine harvesters John Deere 9880 and New Holland CR 9080 at harvest of cereals and oilseed rape.

WEBER, Michal January 2012 (has links)
The aim of this thesis was to compare the activity and quality of work of the combine harvester New Holland CR 9080 and John Deere 9880 STS at harvest of cereals and oilseed rape and their simple economic evaluation. The thesis was focused on comparing losses and influence of moisture of harvested crops on the size of the losses, on the quality of crushing and the spreading of plant residues. Then the inf luence of moisture of harvested crops on the quality of crushing and the spreading of plant residues, analysis of performance and consumption of diesel were compared.
22

Porovnání sklízecích mlátiček různých výrobců při sklizni obilovin a řepky

ADAMEC, Petr January 2018 (has links)
The diploma thesis on comparison of combine harvesters in terms of work quality is based on professional literary research, which describes the parts of combine harvesters from adapters to threshing devices. The methodology of this thesis describes the procedure for obtaining results and values for comparison between John Deere 9640 WTS, New Holland TC5060, Claas Lexion 450 and Sampo Comia C8 combine harvesters during work. The results and the conclusion of the work compare the calculated, measured and determined results achieved precisely according to the methodology of 2017. The combine harvesters are compared in the areas of work quality, namely in the lossability, the theoretical throughput, the quality of spreading and crushing of straw and finally in efficiency and fuel consumption. The work also includes the costs associated with opearting combine harvesters.
23

SISTEMATIZAÇÃO DE CONHECIMENTO PARA O PROJETO DE PLATAFORMAS DE COLHEITA DE FEIJÃO / KNOWLEDGE SYSTEMATIZATION FOR THE DESIGN OF HARVEST HEADERS OF BEANS

Bisognin, André 21 September 2011 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Due to the need to increase in production and to the high rates of losses in the header because of machines with low efficiency in harvesting, it is presented, in this thesis the knowledge systematization needed to develop new header designs to harvest beans. This work presents the machines used for the harvest of beans, the harvesting systems, and a list of influencing factors that determine the knowledge required for new projects. In the patent records, harvesters able to carry out all the harvest s phases, machines for cutting or pulling off plants, addition or replacement parts for harvesters, and machines with different technologies were found. The result of a search for machines in the market showed the main characteristics of headers such as mechanical and hydraulic couplings, dimensions and power transmission systems that are used. A comparison among subsystems was made, and it was noticed that, although the machines are designed for the same culture, and the systems are virtually identical, there are some quite different adjustments, and, in some cases, they do not observe agronomical recommendations, showing that the optimization of designs is possible. It is presented a study on the technologies in harvesting and the size relation of machines that enable their construction followed by the four main categories related to the influencing factors in the project (project scope examination, operating environment characteristics, ratification criteria, and machines available in the market). It was observed that there are still potential improvements in the recorded designs in the patents including the exploration of new concepts. It was observed that many machines recorded in patents are not found in the market. Among the possible reasons for this, there is the fact that the great majority of machines registered in patents carry out the harvest by individualizing the planting lines, which is a characteristic that does not have a good market acceptance. / Em virtude da necessidade de aumento da produção e dos altos índices de perdas na plataforma decorrentes de máquinas com baixa eficiência na colheita, apresenta-se, nesse trabalho, a sistematização de conhecimentos necessários para novos projetos de plataformas de colheita de feijão. O trabalho apresenta as máquinas atualmente utilizadas para colheita de feijão, os sistemas de colheita e a relação dos fatores de influência que determinam a base de conhecimento necessária para projetos. Foram encontrados nos registros de patentes colhedoras capazes de realizar todas as etapas da colheita, máquinas para corte ou arranquio das plantas, peças para adição ou substituição nas colhedoras e máquinas com tecnologias diferenciadas. A pesquisa por máquinas disponíveis no mercado mostrou as características gerais das plataformas como acoplamentos mecânicos e hidráulicos, dimensões e os sistemas de transmissão de potência utilizados. Foi realizada uma comparação entre os subsistemas e notou-se que, embora as máquinas sejam destinadas à mesma cultura e possuem sistemas praticamente idênticos, possuem algumas regulagens bastante distintas, em alguns casos não atendendo às recomendações agronômicas, demonstrando espaço para otimização dos projetos. É apresentado um estudo sobre as tecnologias na colheita e a relação de tamanho das máquinas que viabilizam sua construção, seguida, das quatro principais categorias relacionadas aos fatores de influência no projeto (exame do escopo, características do ambiente operacional, critérios de homologação, e, máquinas disponíveis no mercado). Foi observado que há ainda potencial de melhorias dos projetos depositados em patentes, inclusive com exploração de novas concepções. Muitas máquinas registradas em patentes não são encontradas no mercado. Dentre os prováveis motivos está o fato de que a maioria das máquinas registradas realiza a colheita individualizando as linhas de plantio, característica que não apresta boa aceitação no mercado.
24

Perdas quali-quantitativas na colheita mecanizada de sementes de amendoim (Arachis hypogaea L.)

Barrozo, Leandra Matos [UNESP] 03 April 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-04-03Bitstream added on 2014-06-13T18:34:39Z : No. of bitstreams: 1 barrozo_lm_me_jabo.pdf: 1167406 bytes, checksum: a14ce668242f0784c3da533068d2476d (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O experimento foi conduzido na área da Fazenda de Ensino, Pesquisa e Produção e nos Laboratórios de Análises de Sementes e Fitopatologia da Faculdade de Ciências Agrárias e Veterinárias – FCAV/UNESP, Câmpus de Jaboticabal. O objetivo foi verificar as perdas quantitativas e qualitativas da cultura do amendoim, cultivar Runner IAC 886, em função das velocidades de arranquio e recolhimento. Foram utilizadas duas velocidades de arranquio (4,3 e 5,0 km h-1) e três de recolhimento (3,5; 4,6 e 6,2 km h-1). Foram avaliadas as perdas visíveis (PVA), perdas invisíveis (PIA), as perdas totais (PTA), perdas visíveis totais (PVT) e perdas totais na colheita (PTC), dimensionamento das leiras, distribuição de palhas e produtividade real. Para a qualidade fisiológica foram utilizados os seguintes testes: germinação em areia e em papel, primeira contagem de germinação, índice de velocidade de emergência, massa seca de plântulas, envelhecimento acelerado, condutividade elétrica, emergência de plântulas em campo e tetrazólio. Para análise estatística no arranquio, foi utilizado o delineamento inteiramente casualizado com duas velocidades de arranquio. No recolhimento foi utilizado o delineamento em blocos casualizados em parcelas sub-divididas. As parcelas foram compostas por duas velocidades de arranquio, e as sub-parcelas por três velocidades de recolhimento Para a qualidade fisiológica os dados foram submetidos ao teste de Shapiro-Wilk e após foram submetidos à análise de variância pelo teste F juntamente com os dados de sanidade, e as médias comparadas por meio do teste de Tukey com nível 5% de significância. As velocidades máximas e mínimas não influenciaram nas perdas quali-quantitativas das sementes de amendoim. / The experiment was carried out in the experimental FARM and in the Analysis and in the Phytopatology Laboratories belonging to College of Agriculture, São Paulo State University, Campus of Jaboticabal. The objective of this research was to quantify the losses of peanut crop harvesting and, also the qualitative, it was used a cultivar Runner IAC 886, and was analyzed the effect of the groundnut digger and the harvesting combine speeds. Were used two groundnut digger speeds (4.3 and 5.0 km h-1) and three harvesting combine speeds (3.5; 4.6 and 6.2 km h-1). In the digging process were evaluated the visible losses (PVA), the invisible losses (PIA), total losses groundnut digger (PTA), total visible losses (PVT), total losses in the crop (PTC), design of piles, distribution of straws and the real production. To the physiological quality were used the germination percentage (in sand and paper), first germination count, speed of emergence, seedling dry matter, accelerated aging, electrical conductivity, seedling emergence at field conditions and tetrazolium. For the statistical analysis it was used a completely randomized design consisting of two groundnut digger speed. In the combined harvesting was used a randomized block design in a split plot scheme. The plots were composed by two digger speeds and the split split plot by three combine harvesting speeds. The physiological seed quality were analized by the Shapiro-Will test and after were submitted to the analys of variance together with the sanity data, and the means compared by the Tukey test at 5% level of probability. The maximum and minimum speeds didn't influence in the qualitatife and quantitative losses of the peanut seeds.
25

Avaliação energética da secagem combinada de milho na região de Pedrinhas Paulista, SP

Ribeiro, Jader Picanço [UNESP] 30 September 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-09-30Bitstream added on 2014-06-13T20:52:23Z : No. of bitstreams: 1 ribeiro_jp_me_botfca.pdf: 469725 bytes, checksum: 285a6faae62d7efd022df80018a228fe (MD5) / Universidade Estadual Paulista (UNESP) / A secagem combinada consiste na utilização de um secador em alta temperatura, para reduzir o teor de umidade dos grãos até 16-18% b.u., e, então, proceder a secagem com ar em temperatura próxima à ambiente, até os grãos atingirem a umidade ideal para o armazenamento. Tendo em vista a possibilidade de aplicação deste método para a secagem do milho produzido na região de Pedrinhas Paulista - SP, o presente trabalho teve por objetivo estudar a sua viabilidade, tendo como referência a secagem convencional em alta temperatura, avaliando parâmetros relativos ao consumo de energia, operacionalidade do processo e qualidade do produto seco. O trabalho foi realizado, em escala real, utilizando um secador contínuo, de fluxo misto e com fornalha a lenha. A secagem com ar natural transcorreu num armazém graneleiro dotado de sistema de aeração. Foram realizadas três repetições para cada tratamento para coleta dos dados e cálculos dos parâmetros energéticos. Um modelo computacional de simulação de secagem a baixa temperatura foi empregado para determinar as vazões mínimas de ar necessárias para a região em estudo. No programa de simulação, foram utilizados os dados históricos (10 anos) de médias diárias de temperatura e umidade relativa do ar ambiente da região estudada. Os resultados obtidos comprovaram ser viável a utilização da metodologia de secagem combinada de milho para a região de Pedrinhas Paulista - SP, melhorando a eficiência energética do sistema, com redução média de 30% no consumo total de energia e, aumentando em aproximadamente 29% a capacidade de secagem da unidade, agilizando as operações de recepção, pré limpeza e secagem,além de permitir redução de custos operacionais do processo total de secagem de 22%, mesmo com aumento no consumo de energia elétrica... / The combined drying process consists on using a high temperature drier, which reduces the humidity level on grains up to 16-18% w.b., followed by drying with air near to ambient temperature, until the grains reach the ideal content moisture for storage. Keeping in mind the possibility to apply this drying method for corn produced on Pedrinhas Paulista region - SP, the current process aimed to study its feasibility, keeping the conventional high temperature drying method as a reference, assessing related energy consumption parameters, process operation functionality and dry product quality. This work was carried on, in real scale, using a mixed flow continuous drier with a wood furnace. The drying process with natural air happened on a grain store with ventilation system. In order to collect data and subsequent calculation of energetic parameters, each treatment was repeated three times. A computer simulation model of low temperature drying process was applied to determine minimum necessary airflow for the region under study. The simulation program used historic data (10 years) of the ambient air daily average temperature and humidity of this region. The results proved the feasibility of the combined drying methodology for corn on the Pedrinhas Paulista region - SP, improving the system energetic efficiency with 30% less than energy, increase 29% the drying capacity, optimizing operations of reception, pre-cleaning and drying. Furthermore, it allows 22% cost reduction on the total drying process, even considering the increase of electricity consumption. The study of the minimum airflow drying system using air temperature close to ambient showed the specific low flow applied on the real model analysed, indicating a possible impact on grain quality, when ambient conditions present low adiabatic potential for drying...(Complete abstract, click electronic access below)
26

Análise do sistema de espalhamento de palha em colheitadeiras de grãos

Tolotti, Fabrício Carboni January 2018 (has links)
Este trabalho tem como objetivo analisar a influencia da configuração física do sistema de espalhamento de palha em colheitadeira de grãos na eficiência do espalhamento da palha, visando cobertura mais uniforme do solo de cultivo. Tal processo produzirá melhoramentos no próximo plantio, pois espalhamento mais uniforme de palha evita perdas de nutrientes do solo por incidência luz solar, assim como previne erosão hídrica e eólica. Para analisar a influencia dos parâmetros da configuração física do sistema espalhador de palha foram realizados testes alterando parâmetros como quantidade de pás, ângulo de pás, rotação dos rotores, diâmetro dos rotores, defletor central e vazão de material. Devido à importância econômica no cenário nacional e mundial, utilizou-se a cultura de soja e os testes foram realizados em laboratório seguindo as normas da Sociedade Americana de Engenheiros Agrícolas e Biológicos (ASAE). O trabalho visa fornecer dados que auxiliem designers no desenvolvimento de novos projetos de gerenciamento de resíduos, de modo que venham a aumentar a eficiência desses sistemas, contribuindo com o crescimento da agricultura em no país. Os resultados apontam que a geometria do defletor central apresenta o parâmetro de maior influencia na uniformidade de cobertura da palha ao solo. / The objective of this work is to analyze the influence of the physical configuration of the straw spread system in grain harvester on the efficiency of the straw spread, aiming at a more uniform coverage of the crop soil. This process will produce improvements in the next planting, because more uniform straw spread prevents soil nutrient losses by sunlight, as well as prevent water and wind erosion. In order to analyze the influence of the parameters of the physical configuration of the straw spreader system, tests were performed changing parameters such as blade quantity, blade angle, rotor rotation, rotor diameter, central deflector and material flow. Due to the economic importance in the national and world scenario, the soybean crop was used and the tests were carried out in laboratory according to the standards of the American Society of Agricultural and Biological Engineers (ASAE). The work aims to provide data to assist designers in the development of new waste management projects, so that they will increase the efficiency of these systems, contributing to the growth of agriculture in the country. The results indicate that the geometry of the central baffle presents the parameter of greatest influence on the uniformity of covering of the straw to the soil.
27

Optimization of combine processes using expert knowledge and methods of artificial intelligence / Optimierung von Mähdruschprozessen unter Nutzung von Expertenwissen und Methoden der Künstlichen Intelligenz

Eggerl, Anja 10 January 2018 (has links) (PDF)
Combine harvesters are used to gather plants from the field and separate them into the components of value, the grain and the straw. The optimal utilization of existing combine potential is an inevitable task to maximize harvest efficiency and hence to maximize profit. The only way to optimize the threshing and separation processes during harvest is to adjust the combine settings to existing conditions. Operating permanently at optimal harvest efficiency can only be achieved by an automatic control system. However, for reasons of transparency and due to lack of sensors, the approach in this thesis is a combined development of an interactive and an automatic control system for combine process optimization. The optimization of combine processes is a multi-dimensional and multi-objective optimization problem. The objectives of optimization are the harvest quality parameters. The decision variables, the parameters that can be modified, are the combine settings. Analytical optimization methods require the existence of a model that provides function values in dependence of defined input parameters. A comprehensive quantitative model for the input-output-behavior of the combine does not exist. Alternative optimization methods that handle multi-dimensional and multi-objective optimization problems can be found in the domain of Artificial Intelligence. In this work, knowledge acquisition was performed in order to obtain expert knowledge on combine process optimization. The result is a knowledge base with six adjustment matrices for different crop and combine types. The adjustment matrices contain problem oriented setting adjustment recommendations in order to solve single issues with quality parameters. A control algorithm has been developed that is also capable of solving multiple issues at the same time, utilizing the acquired expert knowledge. The basic principle to solve the given multi-objective optimization problem is a transformation into one-dimensional single-objective optimization problems which are solved iteratively. Several methods have been developed that are applied sequentially. In simulation, the average improvement from initial settings to optimized settings, achieved by the control algorithm, is between 34.5 % and 67.6 %. This demonstrates the good performance of the control algorithm.
28

Fault location on mixed overhead line and cable network

Han, Junyu January 2015 (has links)
Society is increasingly concerned about the environmental impact of energy systems, and prefers to locate power lines underground. In future, certain socially/environmentally sensitive overhead transmission feeders will need to include underground cable sections. Fault location, especially when using travelling waves, become complicated when the combined transmission line includes a number of discontinuities, such as junction points, teed points and fault points. Consequently, a diverse range of fault locators were developed in this thesis, and the performance of the proposed fault locators investigated. For a combined transmission line (CTL), consisting of one or more overhead line sections and one or more underground cable sections, a hybrid fault location scheme is proposed. This utilises the robustness of an impedance based distance algorithm and the accuracy, but stability concerns, of a travelling wave based fault locator, to determine the faulted section. The distance algorithm can determine the approximate fault location, but if the fault is located near an “underground-overhead” junction point, the accuracy is not sufficient to decide whether the fault is located on the overhead or the underground section. This thesis proposes utilizing a single end travelling wave fault locator to improve the accuracy of the fault location decision. The single end travelling wave fault locator can determine the fault section according to the permutation of the polarity of the “special surges”, which is especially important when the fault is close to a junction point. However, this single end fault locator fails in certain “blind” areas, wand these require the use of a distance relay to help determine fault section. Simulation results demonstrated that this hybrid fault locator can reliably determine which section of the feeder is faulty. For all types of CTL, including teed networks, the multiple-end travelling wave fault locator, utilising the arrival time at the feeder ends of the first fault instigated surges, can estimate the fault location. One of the main features of the proposed fault locator is the classification of the time difference between the arrivals of a fault instigated surge at the feeder ends as standard values, when the fault is located at each of the junction points or teed points. Comparing the time differences measured during an actual fault with these standard values allows the faulted feeder section to be estimated. The simulation results show this multiple-end travelling wave fault locator is highly reliable and suitable for application on combined overhead and underground transmission lines.
29

Análise do sistema de espalhamento de palha em colheitadeiras de grãos

Tolotti, Fabrício Carboni January 2018 (has links)
Este trabalho tem como objetivo analisar a influencia da configuração física do sistema de espalhamento de palha em colheitadeira de grãos na eficiência do espalhamento da palha, visando cobertura mais uniforme do solo de cultivo. Tal processo produzirá melhoramentos no próximo plantio, pois espalhamento mais uniforme de palha evita perdas de nutrientes do solo por incidência luz solar, assim como previne erosão hídrica e eólica. Para analisar a influencia dos parâmetros da configuração física do sistema espalhador de palha foram realizados testes alterando parâmetros como quantidade de pás, ângulo de pás, rotação dos rotores, diâmetro dos rotores, defletor central e vazão de material. Devido à importância econômica no cenário nacional e mundial, utilizou-se a cultura de soja e os testes foram realizados em laboratório seguindo as normas da Sociedade Americana de Engenheiros Agrícolas e Biológicos (ASAE). O trabalho visa fornecer dados que auxiliem designers no desenvolvimento de novos projetos de gerenciamento de resíduos, de modo que venham a aumentar a eficiência desses sistemas, contribuindo com o crescimento da agricultura em no país. Os resultados apontam que a geometria do defletor central apresenta o parâmetro de maior influencia na uniformidade de cobertura da palha ao solo. / The objective of this work is to analyze the influence of the physical configuration of the straw spread system in grain harvester on the efficiency of the straw spread, aiming at a more uniform coverage of the crop soil. This process will produce improvements in the next planting, because more uniform straw spread prevents soil nutrient losses by sunlight, as well as prevent water and wind erosion. In order to analyze the influence of the parameters of the physical configuration of the straw spreader system, tests were performed changing parameters such as blade quantity, blade angle, rotor rotation, rotor diameter, central deflector and material flow. Due to the economic importance in the national and world scenario, the soybean crop was used and the tests were carried out in laboratory according to the standards of the American Society of Agricultural and Biological Engineers (ASAE). The work aims to provide data to assist designers in the development of new waste management projects, so that they will increase the efficiency of these systems, contributing to the growth of agriculture in the country. The results indicate that the geometry of the central baffle presents the parameter of greatest influence on the uniformity of covering of the straw to the soil.
30

GRAIN HARVEST LOGISTICS TRACKING TOOLS

Logan Joshua Heusinger (11820410) 18 December 2021 (has links)
Farmers run complex operations to fully plant, manage, grow, and harvest crops through the seasons. To help alleviate the tough decision-making process, tools have been created to inform farmers about their machinery and field status. GPS localization and machine state identification provides useful information to farm managers. A tool was created that successfully utilizes GPS data taken from loggers on tractors, combines, and grain trucks to successfully identify the states of all the machines in the field, including, idle, active, on the go, and stationary unloading. Initial results of the algorithm provide a 96% success rate in determining the state of the combine during harvest. Additionally, the algorithm was accurate at determining the state of grain carts and grain trucks at the boundaries of the field 94% of the time. In addition to GPS state identification, LoRa was identified as a potential technology which could link grain trucks and combines in real time providing useful information for in field decision making. Using a mobile end node and stationary gateway, testing was done to evaluate the performance and range of LoRa at long range and speeds ranging from 8 km/h to 96 km/h. Testing revealed a packet reliability of 77% at 8 km/h and a packet reliability of 43% at 96 km/h. A sharp decline in packet reliability was identified around a speed of 16km/h. <br><br>

Page generated in 0.0664 seconds