This master's thesis project investigates the impact of hydrophobicity and topology on dry and wet macroscopic particle accumulation on surfaces. The report begins by outlining the challenges associated with this phenomenon and the existing theories and methods used to study it, including adhesion, surface engineering, the Lotus effect, and humidity. The method chapter presents the case study of grass accumulation for robotic lawn mowing application and describes experiments conducted to simulate the accumulation of grass during robotic lawn mowing. These experiments explore two different phenomena: the accumulation of grass that is already stuck to a surface and the process by which grass initially sticks to a surface. Experiments have been done to change the hydrophobicity level of certain specimens and investigate how hydrophobicity and humidity affect the stickiness of grass when already accumulated on a surface. In addition, experiments are conducted by throwing grass towards surfaces with different hydrophobicity and topology to determine the influence of these variables on accumulation. Finally, a physical field test is conducted. The findings indicate that hydrophobicity up to 108,2° water contact angle has a low impact on both static and dynamic grass accumulation. Increased hydrophobicity does not tend to decrease grass accumulation, even showing increased accumulation in some experiments. Humidity and the wetness of the grass are more important factors. Experiments have shown that a textured surface can decrease the accumulation, showing significant results in a controlled environment. However, these results did not transfer over in a significant way to a real robotic lawn mowing situation.

Purpose:The purpose of this thesis was to identify a useful solution to find the location of a broken boundary wire. By useful we mean that the solution should be inexpensive, user friendly and accurate. However, this thesis will only investigate the accuracy of the method where the hypothesis is that an investigated method is applicable for all underground wires. Method:This study conducted a literature research in order to investigate what methods that are used in other industries to locate faults in underground, low-voltage electrical wires. After the research, the most commonly used fault locating methods were described and the one that seemed most useful was chosen as a possible solution.For the solution to be useful the accuracy was investigated. The method used to conduct an experiment and gather data to validate the solution was Design Science Research. Result:Three methods were investigated as possible solutions:Time Domain Reflectometry (TDR), Frequency Domain Reflectometry (FDR) and Murray bridge where experiments were conducted using TDR.TDR proved to be unapplicable in locating faults in boundary wires, although it was confirmed to be a valid solution to locate faults in coaxial cables with <1% error margin.What makes TDR and other reflectometry methods unsuitable methods within the autonomous lawn mower industry is the lack of characteristic impedance in the used boundary wires. The hypothesis that an investigated method is applicable for all underground wires is thereby refuted. Limitations:Experiments were conducted in laboratory environment with a signal generator and an oscilloscope. One experiment was conducted on a boundary wire in the ground which provided no reflected signal.

Made available in DSpace on 2017-07-10T17:48:22Z (GMT). No. of bitstreams: 1 Francieli_Batista_Silva.pdf: 721871 bytes, checksum: ef68182f64f3e618bb3a8151fe1ba5e5 (MD5) Previous issue date: 2011-03-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Two experiments were conducted to evaluate ways to use of oat hay, grazing and cutting. The first test evaluated the structural characteristics, chemical composition and digestibility in vitro dry matter (DM) and crude protein (DIVPB) of oat (Avena sativa IPR 126), under different management systems: grazing, cutting and free growth in two heights: 15 and 20 cm in three periods (July, August and September) with a mean interval of 25 days. In the management free growth, the samples were removed at the same intervals and cutting grazing and the same heights (15 and 20 cm). The design was a block design in a 3x2x3 factorial with three tillage systems, two heights and third assessment periods, with three replications. The results show that the dry matter production, production of straw, canopy height and apical meristem height was greater when the oats were not subjected to no management. On the same system on crude protein was higher in the first and cutting the fibrous fractions NDF, ADF, hemicellulose and lignin increased in the third cut. In cutting and grazing managements showed no difference in production dry matter and reduction in production from first to second period and those for the third. The same was true for straw production. The system cutting promoted greater number of tillers and apical meristem increased with the cuts in all managements. The heights of little influence on management characteristics evaluated. The second experiment was conducted with the objective to evaluate structural and productive, straw production residual rates of dehydration, chemical composition and occurrence of fungi in fresh forage and hay with oats made black and white under two cutting heights. The experimental design was a randomized block factorial 2x2 (two species of oats and two cutting heights: 10 and 20 cm) with five replications. The cut was done with mower-conditioner beaters with fingers free. The crude protein values were higher in oat only to be cut (14.15%). The oat showed nutritionally inferior to oat with higher levels of ADF and lignin. There was no effect of cutting height on the composition chemical, but this has interfered in the production of dry matter and the residue after cutting, with higher production with the cut to 10 cm (P <0.05) and increased production of waste in the cut to 20 cm (p<0.05). The oat white promotes hay with better nutritional quality and cutting heights interfere directly on dry matter yield and residue left after harvest / Foram conduzidos dois experimentos com o objetivo de avaliar formas de utilização da aveia: feno, pastejo e corte. O primeiro ensaio avaliou as características estruturais, a composição bromatológica e a digestibilidade in vitro da matéria seca (DIVMS) e da proteína bruta (DIVPB) da aveia branca (Avena sativa IPR 126), sob diferentes formas de manejo: pastejo, corte e crescimento livre sob duas alturas: 15 e 20 cm em três períodos de avaliação (julho, agosto e setembro), com intervalo médio de 25 dias. No manejo crescimento livre, as amostras eram retiradas nos mesmos intervalos de corte e pastejo e nas mesmas alturas (15 e 20 cm). O delineamento foi em blocos casualizados em esquema fatorial 3x2x3 com 3 sistemas de manejo; duas alturas e 3 períodos de avaliação, com 3 repetições. Os resultados encontrados mostram que a produção de matéria seca, produção de palhada residual, altura de dossel e altura de meristema apical foi superior quando a aveia não foi submetida a nenhum manejo. No mesmo sistema a proteína bruta foi superior no primeiro corte e as frações fibrosas FDN, FDA, hemicelulose e lignina elevaram-se no terceiro corte. Nos manejos corte e pastejo não houve diferença na produção de matéria seca, com redução na produção do primeiro para o segundo período e destes para o terceiro. O mesmo ocorreu para a produção de palhada. O sistema corte promoveu maior número de perfilhos e o meristema apical elevou-se com os cortes em todos os manejos. As alturas de manejo pouco influenciaram nas características avaliadas. O segundo experimento foi conduzido com o objetivo de avaliar as características estruturais e produtivas, produção de palhada residual, taxas de desidratação, composição bromatológica e a ocorrência de fungos na forragem fresca e nos fenos obtidos com a aveia branca e preta sob duas alturas de corte. O delineamento experimental foi em blocos casualizados em esquema fatorial 2x2 (duas espécies de aveia e duas alturas de corte: 10 e 20 cm), com 5 repetições. O corte foi realizado com ceifadeira-condicionadora com batedores de dedos livres. Os valores de proteína bruta foram superiores na aveia branca somente no momento do corte (14,15%). A aveia preta mostrou qualidade nutricional inferior a aveia branca com teores superiores de FDA e lignina. Não houve interferência da altura de corte na composição bromatológica, mas esta interferiu na produção de matéria seca e no resíduo após o corte, com valores mais elevados de produção com o corte a 10 cm (P<0,05) e maior produção de resíduo no corte a 20 cm (p<0,05). A aveia branca promove feno com melhor qualidade nutricional e as alturas de corte interferem diretamente na produção de matéria seca e resíduo pós colheita

Autonomous robots are becoming a bigger part of our society. This thesis aims to evaluate a robot testing dashboard (RTD) that can be used as a new way of finding improvements when developing autonomous robots that do not use machine learning. The method that is used is design science research, which is used when creating and evaluating an artifact to address a practical problem. In our case the artifact isthe RTD. This project was performed at a company called Greenworks, which among other things develops and sells autonomous lawn mowers. The company wants to find new testing methods to help develop their autonomous lawnmowers. The RTD is created to visualize the inputs that the lawn mower utilizes to perform its tasks. A human pilot will then control the lawn mower, by only looking at that visualized data. If the pilot using the RTD can execute the same tasks as the lawn mower in its autonomous mode, the test results can be analyzed to see whether the human has done some parts of the tasks differently. The best outcome from the analysis of the test results is to find areas of improvement that can be implemented into the autonomous lawn mower design, both in software and hardware. For this purpose, an RTD was built and tested at Greenworks. From the tests using the RTD we concluded that it is helpful in the testing process, and we could find areas of improvements after analysis of our tests. However, the use of the RTD will require more time and resources compared to other methods. Each company that uses a similar dashboard concept will have to evaluate if the benefits are worth the time. Furthermore, the concept may not suit all areas of robotics but does seem to suit situations where a human can have an advantage over robots, such as in creative problem solving.

Machine vision is hot research topic with findings being published at a high pace and more and more companies currently developing automated vehicles. Robotic lawn mowers are also increasing in popularity but most mowers still use relatively simple methods for cutting the lawn. No previous work has been published on machine learning networks that improved between cutting sessions by automatically collecting data and then used it for training. A data acquisition pipeline and neural network architecture that could help the mower in avoiding collision was therefor developed. Nine neural networks were tested of which a convolutional one reached the highest accuracy. The performance of the data acquisition routine and the networks show that it is possible to design a object detection model that improves between runs.

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The thesis deals with a concept of turning a conventional petrol powered lawn mower to a battery powered solution which is powered by lithium cells. A division to three chapters, comparison, mechanical and electrical, provides fluency of the whole design and further realization. The arrangement of chapters is performed so that the continuity of the thesis is maintained. Calculations of parameters of every motor and transmission with choosing particular devices are just a part of much interesting information which can be found in this thesis. All new components have full documentation except those which were changed during manufacturing. The electrical part explains every part of the schematics in detail. The realization contains difference between preliminary design and further production, manufacturing of the PCB and powering up the motor drives. The last part of the thesis contains temperature measurements of the device at no load.

An Experimental Diagnostic Tool (EDT) was developed to increase the efficiency of the diagnostic process of robotic lawn mowers which resulted in a 200% productivity increase when utilizing a proposed formula specifically designed for the diagnostic process of robotic lawn mowers. The tool does not only extract and process data from the robotic lawn mower wirelessly but also highlights potential faults through an intuitive and easy-to-use interface - empowering servicing technicians who perform the diagnostics to perform at a higher level. Further, efficiency is a term widely used in various domains and contexts when measuring the capacity of a process. Proposed general definitions of the term have been given by previous authors and researchers. However, due to a lack of universally set definitions which fit all situations, the term remains ambiguous when improvements to a specific process are needed. The unclear definition is due to the variations within each process affecting the definition of both the term itself, but also similar terms fundamentally connected to it such as productivity, performance, and profitability. The following report contains an investigation of exploratory research where the understanding of efficiency and its related concepts are analyzed within the after-sales diagnostic process of robotic lawn mowers.

Cette thèse vise à la conception de nouveaux algorithmes rapides en calcul numérique via les matrices de Toeplitz. Tout d'abord, nous avons introduit un algorithme rapide sur le calcul de l'inverse d'une matrice triangulaire de Toeplitz en se basant sur des notions d'interpolation polynomiale. Cet algorithme nécessitant uniquement deux FFT(2n) est manifestement efficace par rapport à ses prédécésseurs. ensuite, nous avons introduit un algorithme rapide pour la résolution d'un système linéaire de Toeplitz bande. Cette approche est basée sur l'extension de la matrice donnée par plusieurs lignes en dessus, de plusieurs colonnes à droite et d'attribuer des zéros et des constantes non nulles dans chacune de ces lignes et de ces colonnes de telle façon que la matrice augmentée à la structure d'une matrice triangulaire inférieure de Toeplitz. La stabilité de l'algorithme a été discutée et son efficacité a été aussi justifiée. Finalement, nous avons abordé la résolution d'un système de Toeplitz bandes par blocs bandes de Toeplitz. Ceci étant primordial pour établir la connexion de nos algorithmes à des applications en restauration d'images, un domaine phare en mathématiques appliquées. / This thesis aims to design new fast algorithms for numerical computation via the Toeplitz matrices. First, we introduced a fast algorithm to compute the inverse of a triangular Toeplitz matrix with real and/or complex numbers based on polynomial interpolation techniques. This algorithm requires only two FFT (2n) is clearly effective compared to predecessors. A numerical accuracy and error analysis is also considered. Numerical examples are given to illustrate the effectiveness of our method. In addition, we introduced a fast algorithm for solving a linear banded Toeplitz system. This new approach is based on extending the given matrix with several rows on the top and several columns on the right and to assign zeros and some nonzero constants in each of these rows and columns in such a way that the augmented matrix has a lower triangular Toeplitz structure. Stability of the algorithm is discussed and its performance is showed by numerical experiments. This is essential to connect our algorithms to applications such as image restoration applications, a key area in applied mathematics.