Projeto e Detalhamento de Hardware do Sistema Embarcado para Controle de Vôo de um Aerofólio Cabeado

TCC(graduação) - Universidade Federal de Santa Catarina. Centro Tecnológico. Engenharia de Controle e Automação.O UFSCKite é um grupo de pesquisa situado no Departamento de Automação e Sistemas da UFSC que se propõe a investigar e desenvolver tecnologias que aproveitem a energia eólica em elevadas altitudes para geração de energia elétrica. Dentro desta área, o grupo tem dirigido seu foco para o estudo de sistemas que utilizam aerofólios flexíveis cabeados para alcançar estes objetivos. Atualmente, o UFSCKite possui um protótipo simples operacional, capaz de controlar a trajetória dos aerofólios em vôo, mas sem a capacidade de gerar energia elétrica. Um segundo protótipo capaz de realizar o controle do sistema com geração de energia elétrica está em fase de projeto. A primeira parte do trabalho aqui apresentado consiste na revisão da primeira versão da placa eletrônica embarcada do primeiro protótipo. Inicialmente, os componentes de hardware e a primeira versão da placa eletrônica embarcada do primeiro protótipo são descritos. Após isso, os problemas apresentados na primeira versão da placa eletrônica embarcada são analisados e a partir dessa análise uma segunda versão é proposta. Em seguida, os esquemáticos e o leiaute da segunda versão são apresentados. A segunda parte do trabalho aqui apresentado consiste no projeto da placa eletrônica embarcada da unidade de Vôo do segundo protótipo. Para a fundamentação deste projeto, um estudo é feito sobre o problema a ser resolvido. Primeiramente, os componentes de hardware do segundo protótipo são descritos. Em seguida, um projeto informacional do sistema embarcado é apresentado, contendo os seus requisitos, uma proposta de modelo funcional, uma tabela de opções de solução e algumas diretrizes a serem seguidas pelo projeto. Partindo deste projeto informacional, um projeto conceitual é proposto, apresentando de forma conceitual a arquitetura do sistema e as suas interfaces. Por fim, os elementos de hardware escolhidos para compor as interfaces são descritos com profundidade e os circuitos que compõem o projeto da eletrônica embarcada são apresentadosUFSCKite is a research group located in the Automation and Systems Department (DAS) of the Federal University of Santa Catarina (UFSC) that aims to investigate and develop technologies that take advantage of the wind power on high altitudes to generate electricity. The group focus have been the study of sistems that use pumping kites to achieve such goals. Currently, the UFSCKite has a simple operational prototype that controls the flight of a kite, but can’t generate electricity. A second prototype capable of both controlling the flight of the kite and generating electricity is being developed. This work consists on a review of the first version of the first prototype’s embedded electronics. First of all, the first prototype’s hardware components and embedded electronics are described. Next, the problems on the first version of the embedded electronics are analysed, and based on that analysis, a second version is proposed. After that, the second version’s electronic schematics and layouts are presented. In addition to that, the embedded electronic project of the second prototype‘s flight unit is proposed. A study is made based on the second prototype’s project. First, the hardware components are described. Then, an informational project of the embedded system is presented, containing a list of requirements, a functional model and some project guidelines. Based on this informational project, a conceptual project is proposed, presenting in a conceptual form the system’s architecture and it’s interfaces. Last, the hardware components of the interfaces are described and the embedded electronic’s circuits are presented

Multirotor UAV as a platform for acoustic tomography of the atmosphere

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Automação e Sistemas, Florianópolis, 2020.Informações detalhadas acerca do perfil de vento e temperatura de determinada localidade são desejáveis durante o processo de avaliação de potencial eólico. De maneira especial, sistemas de airborne wind energy (AWE) se beneficiam destas informações para determinação de procedimentos de pouso e decolagem e de altitude ótima de operação. Atualmente, os equipamentos de medição de perfil de vento disponíveis no mercado possuem um alto custo, não podem ser empregados em áreas remotas ou não possuem o alcance desejado para aplicações AWE. Esta dissertação propõe uma solução portátil, reutilizável, autônoma e de baixo custo para medir o perfil de vento e temperatura para avaliação de potencial eólico de localidades para aplicações AWE. A solução consiste no uso de um veículo aéreo não-tripulado (VANT) como uma plataforma de instrumentação para um dispositivo de tomografia acústica da atmosfera. A descrição da arquitetura de hardware e software requerida para desempenhar todas as funcionalidades necessárias para operação contínua de dispositivo de tomografia acústica baseado em VANT multirrotor é apresentada. O software de tomografia acústica proposto é aplicado em um modelo de atmosfera de acordo com a configuração de hardware estipulada. Os resultados alcançados em simulação foram comparados com os obtidos de outros perfiladores de vento baseados em VANT e apresentaram um desempenho similar ou superior a estes. Os resultados da dissertação demonstraram que o dispositivo proposto potencialmente tem precisão suficiente para ser utilizado como instrumento de medição atmosférica.Abstract: In the process of wind resource assessment, detailed information about the wind and temperature profile of the site being assessed is desirable. This is specially true for airborne wind energy (Airborne Wind Energy (AWE)) systems, for which this information is relevant in determining the take-off and landing procedures and finding an optimal operating height of the system. Current autonomous devices commercially available are expensive and can not be employed in remote areas or can not reach the desired height range for AWE applications. The present dissertation proposes a portable, reusabe, low-cost automated solution to measure the wind and temperature profile for AWE assessment applications. The solution consists on the usage of an Unmanned Aerial Vehicle (Unmanned Aerial Vehicle (UAV)) as an instrumentation platform of an Acoustic Atmosphere Tomography (AAT) device. A hardware and software architecture for the multirotor UAV-based AAT device is described to perform all of the functionalities required for its full continuous operation. The proposed AAT software is applied to an atmosphere model in accordance to the stipulated hardware setup. The results obtained in simulation environment were compared to other similar UAV-based wind profilers and presented accuracy performances close to or better than them. The dissertation results has shown that the proposed device has the potential to be accurate enough to be used as a weather observation instrument

THEORETICAL AND EXPERIMENTAL ANALYSES OF THE THERMAL RESISTANCE OF A LOOP THERMOSYPHON FOR PASSIVE SOLAR HEATING OF BUILDINGS

This study presents experimental and theoretical analyses of the thermal performance of a two-phase copper-R141b loop thermosyphon, which was developed for solar heating of buildings. A prototype of the so-called wall thermosyphon was built and tested at the Heat Pipe Laboratory of the Federal University of Santa Catarina (Labtucal-UFSC). During the tests, three parameters were varied: purge method, power input levels, and inside wall evaporator roughness. The results show that both purge and vacuum pumps are equally effective in eliminating noncondensable gases from the system. Also, recent boiling heat transfer coefficient literature correlations are in good agreement with the experimental data from the prototype. However, the condensation thermal resistance calculated with the literature correlations do not represent the same trend found in the experiments. The effective thermal resistance of the wall thermosyphon prototype, which comprises the boiling resistance plus the condensation resistance, varies between 0.22 and 0.011°C/W depending on the heat transfer rate from 2.5 to 200 W

Toward Low Earth Orbit (LEO) Applications: the Scientific Journey of the "Space Pulsating Heat Pipe" Experiments

International audienceThis paper shortly summarises the experimental results obtained since 2011 by a large European academic consortium for the scientific conceptualisation, the definition of the technical requirements, the generation of experimental data, and the validation of a numerical code, for the Pulsating Heat Pipes (PHP) experiment on the International Space Station (ISS). The PHP is a passive, wickless thermal device, whereby a two-phase fluid, forming liquid plugs and vapour slugs, moves with a pulsating or circulating motion inside a meandering tube or channel. The PHP may have a very broad range of geometries (flat, tubular, 3D structured), it can dissipate heat from large areas, and it can be suitable for high power applications with low/medium heat fluxes. PHP functioning is based on the capillary effect, which provides the existence of liquid plugs completely filling the channel cross-section, in a way that any expansion or contraction of the vapour slugs will naturally generate a movement of the fluid along the channel axis. For this, it is important that the channel has a cross-section size below a given threshold, which depends on the liquid surface tension and (for a static fluid) on the gravity acceleration. In space, when only residual accelerations are acting, such a static size threshold is virtually infinite, while a finite dynamic threshold exists even in the absence of gravity. The concept of a "Space PHP" was originally developed in 2014 by the team, and from then 17 Parabolic Flight Campaigns (PFC) and 3 Sounding Rocket (SR) experiments have been carried out to generate the data for the preparation of an experiment targeting a Low Earth Orbit (LEO) mission. Both a tubular and a flat plate PHP have been successfully tested in reduced gravity and on ground, by using different combinations of fluids and building materials. The need for having an experiment on a LEO environment is mainly because, during a PFC, only 22sec of reduced gravity are possible, which is a period below the characteristic time for reaching a steady state condition for almost all of the tested devices. Instead, a steady state was reached using the SR campaigns: in this case however, only one experimental condition was achievable, and long-duration data of the PHP performance still remains beyond reach. Several measurement methodologies have been used to characterise the Space PHP, like infrared analysis, high-speed camera visualisation techniques, with data processed with different techniques, from wavelets to inverse heat transfer problem solution. The results clearly showed that PHPs are very interesting for space applications due to their simplicity of construction, the capacity to transfer heat up to several hundred watts, a high power/weight ratio, their geometrical adaptability, and, in particular, the Space PHP will be a breakthrough technology for space thermal management