The diploma thesis is focused on the topic of global satellite navigation of mobile robots. The paper describes the principle of currently available global satellite navigation systems. The main element of the thesis is the proposal of mobile robot navigation algorithm. An integral part is also the design of a mobile robot to verify the functionality of the navigation algorithm. The robot software program is described. At the end, everything is verified by real experiments.

This thesis implements solution for automatic docking for a mobile robot using visual markers. After initial survey of already implemented works, new docking solution is proposed. Feasibility of the solution is verified with tests of marker detection precision. The implementation is tested in a simulation and with a real robot. The functionality of the proposed solution is verified by long-term tests. The result of this work is robot’s ability to navigate known environment to find and dock a charging station. After charging the robot is able to safely disconnect from the station.

In the introductory part of this thesis there is an analysis of methods, which are used for navigation of mobile robots. The main part of the thesis contains a proposal of control system of mobile robot. Robot control system is based on fuzzy modeling. To test the control, a system simulation environment is created in C #, in which experiments were performed.

Orientador: Janito Vaqueiro Ferreira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-20T14:52:32Z (GMT). No. of bitstreams: 1 HernandezBeleno_RubenDario_M.pdf: 6591392 bytes, checksum: fd4c66b4e3769739bb1a4283c418d2d8 (MD5) Previous issue date: 2012 / Resumo: Com o avanço da tecnologia refletida nos sistemas eletrônicos e de computação, os métodos do controle de trajetória no sistema de navegação se tornaram importantes nas diversas aplicações de veículos autônomos, como na geração de mapas, desvio de obstáculos e tarefas de posicionamento. Além disso, o controle pode proporcionar um ganho significativo na confiabilidade, versatilidade e precisão das tarefas robóticas, questões cruciais na maioria das aplicações reais. O presente trabalho tem como objetivo principal apresentar a criação de um veículo autônomo em escala. Para tanto foi desenvolvido um sistema de função sensorial que provê informações sobre a posição e orientação do carro a partir de quatro sistemas sensoriais como GPS, acelerômetro, giroscópio e a bussola (IMU), para que o veículo autônomo possa realizar a rota corretamente, de forma eficiente e segura. Neste projeto foi desenvolvido um software que integra os sistemas de controle e de sensoriamento. Além disso, foi projetado um módulo que controla a posição e orientação do veículo. O robô antes de realizar a manobra calcula a distância mínima relacionada ao próximo ponto da coordenada planejada para trocar sua referência de trajetória satisfazendo a orientação do caminho e do veículo. Para fins de avaliação, foram realizados experimentos em ambientes reais onde o carro percorre um conjunto determinado de coordenadas geográficas sem nenhuma intervenção humana, apresentando resultados do seguimento de trajetórias proposto e validando os sistemas sensoriais, além do algoritmo de controle projetado / Abstract: As electronic and computational systems technology advances, the use of path control methods in navigation systems become very important for different autonomous vehicles applications such as generating maps, avoiding obstacles and carrying out positioning tasks. In addition, controls can help increase the reliability, versatility and precision level of programmed tasks, which is exceedingly significant regarding real applications. The first aim of this work is to present the creation of an autonomous scale vehicle. We have developed a sensor system that provides information about the vehicle's position and orientation through four sensor systems such as gps, accelerometer, gyroscope and compass so that it can effectively and safely cover the right route. This project developed a software, which integrates the control and sensors systems. In addition, a control module was projected for the positioning and orientation of the vehicle. Before the robot turns to any direction, it calculates the minimal distance to the next step of the programmed coordinate, in order to change its own referenced trajectory, satisfying the orientation of the trajectory and the vehicle. For the task validation were done experiments in real life scenarios, where the vehicle follows a determined group of geo-coordinates without any human intervention, presenting results of the purposed following trajectories, validating the sensors systems and the control algorithm / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

To navigate successfully in a previously unexplored environment, a mobile robot must be able to estimate the spatial relationships of the objects of interest accurately. A Simultaneous Localization and Mapping (SLAM) sys- tem employs its sensors to build incrementally a map of its surroundings and to localize itself in the map simultaneously. The aim of this research project is to develop a SLAM system suitable for self propelled household lawnmowers. The proposed bearing-only SLAM system requires only an omnidirec- tional camera and some inexpensive landmarks. The main advantage of an omnidirectional camera is the panoramic view of all the landmarks in the scene. Placing landmarks in a lawn field to define the working domain is much easier and more flexible than installing the perimeter wire required by existing autonomous lawnmowers. The common approach of existing bearing-only SLAM methods relies on a motion model for predicting the robot’s pose and a sensor model for updating the pose. In the motion model, the error on the estimates of object positions is cumulated due mainly to the wheel slippage. Quantifying accu- rately the uncertainty of object positions is a fundamental requirement. In bearing-only SLAM, the Probability Density Function (PDF) of landmark position should be uniform along the observed bearing. Existing methods that approximate the PDF with a Gaussian estimation do not satisfy this uniformity requirement. This thesis introduces both geometric and proba- bilistic methods to address the above problems. The main novel contribu- tions of this thesis are: 1. A bearing-only SLAM method not requiring odometry. The proposed method relies solely on the sensor model (landmark bearings only) without relying on the motion model (odometry). The uncertainty of the estimated landmark positions depends on the vision error only, instead of the combination of both odometry and vision errors. 2. The transformation of the spatial uncertainty of objects. This thesis introduces a novel method for translating the spatial un- certainty of objects estimated from a moving frame attached to the robot into the global frame attached to the static landmarks in the environment. 3. The characterization of an improved PDF for representing landmark position in bearing-only SLAM. The proposed PDF is expressed in polar coordinates, and the marginal probability on range is constrained to be uniform. Compared to the PDF estimated from a mixture of Gaussians, the PDF developed here has far fewer parameters and can be easily adopted in a probabilistic framework, such as a particle filtering system. The main advantages of our proposed bearing-only SLAM system are its lower production cost and flexibility of use. The proposed system can be adopted in other domestic robots as well, such as vacuum cleaners or robotic toys when terrain is essentially 2D.