Embora o ressalto hidráulico seja um assunto já muito estudado, é igualmente um assunto de grande interesse, acerca do qual ainda existem diversos questionamentos a respeito de suas características. Por essa razão, buscou-se neste projeto o desenvolvimento de estudos experimentais e a proposição de um modelo teórico. Os trabalhos experimentais foram desenvolvidos com o uso de um sensor ultrassônico, para aquisição de dados instantâneos da superfície livre, sendo estudados ressaltos com número de Froude na seção supercrítica entre 1,94 e 5,26 e duas condições de controle a montante: comporta plana e vertedor de soleira espessa. As seguintes variáveis foram avaliadas a partir dos experimentos: comprimento do rolo, comprimento do ressalto, intensidade turbulenta vertical, perfil da superfície livre e frequências dos sinais de saída do sensor. Os perfis da superfície livre, considerando-se separadamente os dados de comporta e vertedor, foram ajustados a partir de uma equação heurística e as frequências características foram comparadas com os comprimentos característicos do ressalto. Além disso, foram efetuados registros fotográficos do escoamento com uma câmera de alta velocidade e luz laser para uma condição experimental (com baixo número de Froude supercrítico), sendo a superfície livre detectada por meio de técnicas usuais de processamento de imagens. O perfil médio obtido com o sensor foi semelhante ao perfil das imagens. Em relação ao modelo teórico proposto, este foi desenvolvido a partir de dois volumes de controle (VC) fixos, sendo obtidas duas equações para a relação entre o comprimento do rolo e a altura supercrítica. Verificou-se uma variação de quarenta porcento entre os valores previstos com as equações e os dados experimentais, em função da própria divergência dos dados de comprimento do rolo indicados pelos autores. De forma geral, o estudo mostrou-se relevante por possibilitar a avaliação da estrutura externa do ressalto hidráulico por meio de diferentes abordagens metodológicas. / Althought hydraulic jump has been studied for a long time, it is equally a theme of large interest, which many aspects related to its characteristics remain unanswered. Therefore, the development of experimental studies and the proposal of a theoretical model was sought in this project. The experimental works were carried out using an ultrassonic sensor, in order to acquire instantaneous data of the free surface, being studied hydraulic jumps with inflow Froude number ranging between 1.94 and 5.26 and two upstream control structures: plane gate and broad-crested weir. The following variables were evaluated: roller length, hydraulic jump length, vertical turbulent intensity, free surface profile, frequencies of the output data sensor. The free surface profiles, considering individually the plane gate and broad-crested weir, were adjested using a heuristic equation and characteristic frequencies were compared to the characteristic jump lengths. Furthermore, the flow was photographed using a high speed camera and a laser light for one experimental condition (for low inflow Froude number). The free surface in images were detected trought usual image processing techniques. The mean profile obtained from the sensor was very similar to the images profile. Regarding the theoretical model, it was developed considering two fixed control volumes (VC), obtaining two equations for the roller length and supercritical depth ratio. A variation of forty percent was observed between the predicted and experimental values, due to the own divergence among the roller length data suggested by the authors. Overall, the study was relevant, because it allowed the evaluation of the external structure of hydraulic jumps by means of different methodological approaches.

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2016-11-10T13:48:13Z No. of bitstreams: 2 Dissertação - Rômulo Muriel Mesquita de Oliveira - 2015.pdf: 7641184 bytes, checksum: b650ba6efa2c0aba74125271f293ebcc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2016-11-10T17:42:47Z (GMT) No. of bitstreams: 2 Dissertação - Rômulo Muriel Mesquita de Oliveira - 2015.pdf: 7641184 bytes, checksum: b650ba6efa2c0aba74125271f293ebcc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-11-10T17:42:47Z (GMT). No. of bitstreams: 2 Dissertação - Rômulo Muriel Mesquita de Oliveira - 2015.pdf: 7641184 bytes, checksum: b650ba6efa2c0aba74125271f293ebcc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-02-20 / The increasing number of accidents on roads and highways around the world is causing concern in many government agencies. Because of that, actions have been proposed to eradicate this reality, which claims the lives of millions annually. Within the different types of traffic accidents occurring, one specific has gained space in the media, which involves the door of a vehicle, improperly opened, causing collision with a cyclist, motorcyclist or other vehicle. The law states to be responsible for the accident the one who opened the door without taking proper precautions, however, due to physical and emotional factors that disturb each day more the society, lives in traffic can?t be under the responsibility of a person. Many assistive technologies that helps in decision making or even contributing to road safety, have been submitted to the automotive market, which once included in vehicles would save the lives of thousands. Aware of this, this paper proposes a technology that, through low cost ultrasonic sensor detects possibility of collision on the side of the vehicle and sends alerts to the driver so he or she does not open the door during the moment of risk. For development of this security system was necessary to define which ultrasonic sensor to use, to prepare the case for the hardware accommodation, to build the computer program, to analyze the positioning of the system in the vehicle and to execute experimental tests to validate the ADS (Avoiding Doored System), name given to the collision avoidance system / A elevação do número de acidentes em estradas e rodovias ao redor do mundo vem causando preocupação em muitos órgãos governamentais. Em função disso, ações vêm sendo propostas para erradicação dessa realidade, que tira a vida de milhões anualmente. Dentro os vários tipos de acidentes que ocorrem no trânsito, um muito específico vem ganhando espaço na mídia, aquele envolvendo a porta de um veículo, aberta indevidamente, causando colisão com um ciclista, motociclista ou mesmo outro veículo. A legislação determina ser responsável pelo acidente àquele que abriu a porta sem tomar as devidas precauções, no entanto, devido a fatores físicos e emocionais, que perturbam cada dia mais a sociedade, deixar vidas no trânsito sob responsabilidade de terceiros não é uma escolha prudente. Inúmeras tecnologias assistivas, que auxiliam na tomada de decisão ou mesmo que contribuem para segurança no trânsito, vêm sendo apresentadas ao mercado automobilístico, as quais, uma vez inclusa nos veículos, pouparia a vida de milhares. Nesse contexto, este trabalho apresenta uma proposta de tecnologia que, por meio de sensor ultrassônico de baixo custo, detecta possibilidade de colisão na lateral do veículo devido à abertura da porta e emite alerta ao condutor, de forma que este não abra a porta durante o instante de risco. Para tanto, foi necessário desenvolver um sistema de mapeamento do campo de atuação do sensor, de modo que fosse possível determinar o mais adequado para o desenvolvimento do sistema. Além disso, foi projetado e construído um “case” para acomodação dos periféricos do sistema, desenvolvido o software de controle do sistema e posteriormente foi analisado o posicionamento do sistema no veículo e aplicação de testes experimentais para avaliação funcional do ADS (Avoiding Doored System), assim nomeado o sistema que evita colisões por abertura da porta.

Ultrasonic sensors are commonly used in automobiles to assist driving maneuvers, e.g., parking, because of their cost-effectiveness and robustness. This thesis investigated the feasibility of using an Ultrasonic Sensor Array to locate the 3D position of an object and also using the measurements from the sensor array to train a Convolutional Neural Network (CNN) to classify the objects. A simulated Ultrasonic Sensor array was built in COMSOL Multiphysics. The simulation of ultrasound used Ray Tracing technology to track the path of ultrasound rays. The readouts from the sensor array are used to formulate an optimization problem to address the 3D positioning of the object. We investigated the performance of two optimization methods in terms of the accuracy of the prediction and the efficiency of solving the problem. The average mean absolute error (MAE) and average mean squared error (MSE) of the Nelder-Mead method (without constraints) are 2.66 mm and 12.79 mm2 respectively, the average running time to predict one 3D position is 97.62 ms. The average MAE and average MSE of Powell’s method (with constraints) are 2.84 mm and 23.66 mm2 respectively, average running time to predict one 3D position is 84.68 ms. The result of Powell’s method (without constraints) is much worse than the above two, its average MAE and MSE are 24.93 mm and 7559.46 mm2, average running time is 238.30 ms. The readouts from the sensor array are also used to build eight different datasets of which the data structures are different combinations of the information from the readouts. Each of these eight data sets is used to train a CNN, and the classification accuracy of each CNN indicates that how well the data structure represents the objects. The results showed that the CNN trained by stacked time array 5×5×3 had the best classification accuracy among eight datasets, the classification accuracy on the test set is 85.05%.

This thesis deals with the implementation of a system for measuring the amount of water in the tank using a 12V water pump. The whole system is controlled by the ESP32 microcontroller. The introduction deals with the theoretical analysis of various principles of measuring the level of liquids. The next part deals with the procedure of the construction of the measuring device and its theoretical analysis. The last part of the work deals with the control of the pump and the individual functions that provide this control. The ultrasonic distance sensor AJ-SR04M was chosen for the implementation of the device. The volume of water in the tank is calculated from its data. The ESP32 microcontroller provides system control via a web interface. The whole system was implemented and tested to measure the volume of water and its pumping in the IBC container.

This work deals with navigation of the mobile outdoor robots. It is divided in two parts. In the first part, the mobile robots and their control problem is examined. The technical means for navigation and obstacles avoidance are described and the mathematical means for sensor data fusion and optimal position estimation of the robot are outlined. In the second part the hardware of the robot is described and furthermore it deals with description of the practically realized algorithms for obstacles avoidance and robot navigation.

This master's thesis deals with determination of properties of the ultrasonic sensor SRF05. It is about finding factors that distort or have other negative effects in any way on the proper functionality of these sensors. First of all, it was necessary to program a chip mounted on signal processing board for correct functionality and operation of sensors. Then a few sets of measurements were done to determine the behaviour of sensors for different distances. In addition, we had to carry out many more measurements to find out the influence of temperature, light conditions, material of the sensed surface or cross-noise caused by the use of multiple sensors. In the next step, the approximate shape of the transmitted ultrasound was investigated to determine the zone of detection. The last task of this thesis was to compare the SRF05 sensors with other ultrasonic sensors from different manufacturers.

Bird feeding is somthing most are familiar with, either when children are feeding the swans or adults using some type of bird feeder in the garden. This project took that as inspiration to create something that automatically feed the birds while also monitoring them by capturing a picture and sending out this information as a teet on Twitter. This thesis examined if it was possible to connect different components relatively simple in order to create something more advanced. Research of the components was the first step in order to ensure the ability to create such a product. The following components were used, a Raspberry Pi 3 b+, Raspberry Pi camera module, IKEA PIR sensor, zigbee USB dongel, ultrasonic sensor and a micro servo motor. These components were connected to the Raspberry Pi and tested individually to ensure quality and function. When successfully tested, implementing them together was done and later construction of the mounting brackets and housing was made. Testing was done and results were finalized. This showed that all of our research questions were successfully answered with positive results and further research around implementing AI and weather protection would be usefully to successfully make this a fully functioning product. / Fågelmatning är något de flesta de flesta känner till, antingen när barn matar svanar eller vuxna som har en fågelmatare i trädgården. Det här projektet tog det som inspiration för att skapa något som automatiskt matar fåglar samtidigt som den övervakar funktionen genom att ta kort och skicka denna information som en tweet på Twitter. Den här avhandlingen undersökte om det var möjligt att sammankoppla olika komponenter relativt enkelt för att skapa något mer avancerat. Forskning om komponenterna var det första steget i att undersöka om detta var möjligt. Följande komponenter kom att användas, an Raspberry Pi 3 b+, Raspberry Pi kameramodul, IKEA PIRsensor, zigbee USBdongel, ultraljudsensor och en micro servomotor. Dessa komponenter kopplades in i Raspberry Pi:en och testades individuellt för att säkerhetställa kvalite och funktion. När testerna var lyckade implementerades de tillsammans och konstruktionen av fästen och ytterhölje fördigställdes. Tester gjordes och resultat sammanställdes. Dessa visade att alla våra forskningsfrågor blev besvarade med ett positivt resultat och framtida forskning kring implementeringen av AI och väderskydd är något som skulle kunna möjliggöra detta att bli en fullt fuktionerande produkt.

In the manufacturing industry, product quality assurance is important to ensure customer safety and product quality. The thesis is based on problems identified with calibration of ultrasonic sensors used in quality assurance of rear shafts for trucks and buses. The ultrasonic sensors operate underwater at a frequency above 20 kHz, utilizing the angle of refraction to analyse the bottom part of weld seams for possible defects. The purpose of the thesis has been to assist Syntronic in designing and evaluating different mechanical solutions for an improved sensor mount, with the aim of increasing repeatability and reducing calibration time. The report follows a product development process, where theory of concept generation methods has been applied. Establishment of product requirements through unstructured interviews were made, where qualitative data was collected. Concept generation was used in respect to the product requirements, followed by detailed design of products intended to solve the identified problems. Furthermore, the concepts were analysed using the SolidWorks FEM tool and compared to each other in a concept selection matrix. The result of the investigation is a product that better meets the product requirements compared to the existing product. Physical testing remains, where an initial prototype is developed and implemented in a test rig, gathering additional data. Furthermore, the report provides a foundation for further product development in the discussion chapter. / Inom tillverkningsindustrin finns ett stort behov av kvalitetssäkring av produkter, detta för att garantera dels säkerhet för kunden, dels kvaliteten på produkten. Examensarbetet grundar sig i problemområden som identifierats vid kalibrering av ultraljudssensorer till ett analysinstrument för kvalitetssäkring av bakaxlar till lastbilar och bussar. Ultraljudssensorerna opererar under vattenytan på en frekvens över 20 kHz där brytningsvinkeln nyttjas för att analysera undersidan av svetsfogarna efter eventuella defekter. Syftet med examensarbetet har varit att hjälpa Syntronic konstruera och utvärdera olika mekaniska lösningar för en förbättrad hållare för ultraljudssökarna där koncepten ämnar öka repeterbarheten och minska kalibreringstiden. Arbetet följer en produktutvecklingsprocess, där teori för konceptgenereringsmetoder applicerats. Rapporten presenterar fastställande av produktkrav genom ostrukturerade intervjuer där kvalitativa data samlades in, konceptgenerering med avseende på funktionalitetskraven, detaljkonstruktion av produkter som ämnar att lösa problemen som identifierats. Vidare analyserades koncepten i SolidWorks FEM-verktyg och ställdes mot varandra i en konceptvalsmatris. Resultatet av undersökningen är en slutprodukt som bättre uppfyller produktkraven än befintlig produkt. Fysisk testning återstår där en första prototyp tas fram och implementeras i en testrigg, där ytterligare data samlas in. Vidare har underlag för vidareutveckling av produkten presenterats i diskussionen.

Rubber granulates, used at artificial grass pitches, pose a threat to the environment when leaking into the nature. As the granulates leak to the environment through rain water and snow clearances, they can be transported by rivers and later on end up in the marine life. Therefore, reducing the snow clearances to its minimum is of importance. If the snow clearance problem is minimized or even eliminated, this will have a positive impact on the surrounding nature. The object of this project is to propose a method for deciding when to remove snow and automate the information dispersing upon clearing or closing a pitch. This includes finding low powered sensors to measure snow depth, find a machine learning model to predict upcoming snow levels and create an application with a clear and easy-to-use interface to present weather information and disperse information to the responsible persons. Controlled experiments is used to find the models and sensors that are suitable to solve this problem. The sensors are tested on a single snow quality, where ultrasonic and infrared sensors are found suitable. However, fabricated tests for newly fallen snow questioned the possibility of measuring snow depth using the ultrasonic sensor in the general case. Random Forest is presented as the machine learning model that predicts future snow levels with the highest accuracy. From a survey, indications is found that the web application fulfills the intended functionalities, with some improvements suggested.