In autonomous navigation of mobile robots the dynamic environment is a source of problems. Because it is not possible to model all the possible conditions, the key point in the robot control is to design a system that is adaptable to different conditions and robust in dynamic environments. This study presents a reactive control system for a Khepera robot with the ability to navigate in a dynamic environment for reaching goal objects. The main motivation of this research is to design a robot control, which is robust to sensor errors and sudden changes and adaptable to different environments and conditions. Behavior based approach is used with taking the advantage of fuzzy reasoning in design. Experiments are made on Webots, which is a simulation environment for Khepera robot.

In agent based systems, especially in autonomous mobile robots, modelling the environment and its changes is a source of problems. It is not always possible to effectively model the uncertainity and the dynamic changes in complex, real-world domains. Control systems must be robust to changes and must be able to handle these uncertainties to overcome this problem. In this study, a reactive behaviour based agent control system is modelled and implemented. The control system is tested in a navigation task using an environment, which has randomly placed obstacles and a goal position to simulate an environment similar to an autonomous robot&rsquo / s indoor environment. Then the control system was extended to control an agent in a multi-agent environment. The main motivation of this study is to design a control system which is robust to errors and easy to modify. Behaviour based approach with the advantages of fuzzy reasoning systems is used in the system.

abstract: Advancements in computer vision and machine learning have added a new dimension to remote sensing applications with the aid of imagery analysis techniques. Applications such as autonomous navigation and terrain classification which make use of image classification techniques are challenging problems and research is still being carried out to find better solutions. In this thesis, a novel method is proposed which uses image registration techniques to provide better image classification. This method reduces the error rate of classification by performing image registration of the images with the previously obtained images before performing classification. The motivation behind this is the fact that images that are obtained in the same region which need to be classified will not differ significantly in characteristics. Hence, registration will provide an image that matches closer to the previously obtained image, thus providing better classification. To illustrate that the proposed method works, naïve Bayes and iterative closest point (ICP) algorithms are used for the image classification and registration stages respectively. This implementation was tested extensively in simulation using synthetic images and using a real life data set called the Defense Advanced Research Project Agency (DARPA) Learning Applied to Ground Robots (LAGR) dataset. The results show that the ICP algorithm does help in better classification with Naïve Bayes by reducing the error rate by an average of about 10% in the synthetic data and by about 7% on the actual datasets used. / Dissertation/Thesis / M.S. Electrical Engineering 2011

Veículos autônomos terrestres são um tipo de veículo motorizado guiado de forma autônoma por um sistema computacional, sem necessidade de intervenção humana. Esta pesquisa analisa a Tomada de Decisão autônoma necessária para este tipo de veículo, assim como os processos de navegação e as estruturas de dados que a suportam. Sobre esta análise propõe-se uma arquitetura de Tomada de Decisão para navegação autônoma baseada em dois ideias principais: a sistematização das fontes de dados com as quais o veículo deve interagir em sua navegação em uma hierarquia de prioridades de tratamento e o desenvolvimento de uma estrutura de dados chamada de Grade de Prioridades que permite definir para qual região do ambiente o veículo deve se locomover. Para suportar a arquitetura, formaliza-se um conjunto de processos recomendados de navegação robótica (percepção, posicionamento, planejamento e estratégia de movimento), organizados para suportar a integração com recursos de outras pesquisas do segmento da Robótica Móvel. Para validação da arquitetura, desenvolve-se um sistema de navegação robótica, integrada à uma plataforma robótica real, e realiza-se um conjunto de testes para simular o comportamento da arquitetura em situações de navegação específicas. / Autonomous ground vehicles are a type of motor vehicle autonomously guided by a computer system without human intervention. This research analyzes the autonomous decision making required for this type of vehicle as well as the processes of navigation and data structures that support it. On this analysis, is proposed an architecture of decision making for autonomous navigation based on two fundamental ideas: the systematization of data sources with which a vehicle must interact in their navigation in a hierarchy of priorities and the development of a special data structure called Grid Priorities that defines which region of the environment the vehicle must be moved. Supporting the architecture, a set of processes for robotic navigation (perception, positioning, planning and motion strategy) are proposed and organized to support integration with other research resources in the segment of Mobile Robotics. For validate the architecture, is developed a system of robotic navigation, integrated with a real robotic platform, and is performed a set of tests to simulate the behavior of the architecture in specific situations of navigation.

Orientadores: Janito Vaqueiro Ferreira, Arthur de Miranda Neto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-26T02:40:48Z (GMT). No. of bitstreams: 1 RodriguezRuiz_MariaFernanda_M.pdf: 8751418 bytes, checksum: adc682edc93b0bb96046bdc3bde2c72e (MD5) Previous issue date: 2014 / Resumo: Os veiculos autônomos são uma realidade, mas seu desenvolvimento requer a altos custos. No entanto, a fim de fortalecer os avanços na robótica móvel, há um grande esforço no desenvolvimento de aplicações de baixo custo orientadas aos veículos autônomos, sendo o estudo de métodos de localização uma das áreas de maior interesse, a fim de uma navegação segura. Esta dissertação de mestrado propõe um método de localização híbrida, composto por sensores proprioceptivos e exteroceptivos, e informações adicionais como mapas digitais e reconhecimento de objetos chave, para melhorar a estimação da posição de um veículo terrestre. O sistema está baseado nas informações de posicionamento obtidas por um GPS de baixo custo e também em informações obtidas pelo método de localização referenciada, baseada em um conjunto de dados geográficos disponíveis em uma base de dados que compõe o mapa digital. A técnica de fusão de dados selecionada é baseada no filtro de Kalman estendido (EKF), que combina as informações de diferentes sistemas a fim de aumentar a robustez do sistema de localização. O desempenho do método de localização proposto é verificado através de uma plataforma de localização composta por ferramentas como um servidor de mapas baseado em OpenStreetMap e uma outra de simulação composta por ferramentas como ROS e Gazebo, que inclui um veículo terrestre com sensores embarcados, um mapa digital e objetos chave. A arquitetura selecionada é de fácil adequação para a realização de testes, já que permite simular objetos e sensores bem próximos à realidade / Abstract: The autonomous vehicles are a reality, but its development is equivalent to high costs. However, in order to strengthen the advances in mobile robotics, there is a large effort in developing low cost oriented applications to autonomous vehicles, with the study of methods of finding the area of most interest in relation to the fact achieve a navigation secure. This dissertation proposes a method of hybrid location consists of proprioceptive and exteroceptive sensors, and additional information such as digital maps and recognition of key objects, to improve the estimation of a land vehicle position. The system is based on the positioning information via GPS low cost, and information obtained by the method referenced location, based on a set of available spatial data in a database comprising the digital map. The fusion technique selected data is based on the extended Kalman filter (EKF) that combines the information of different systems in order to increase the robustness of the location system. The performance of the proposed method of location is verified through a location platform consists of a server tools like maps based on OpenStreetMap and another comprising simulation tools such as ROS and Gazebo, which includes a ground vehicle with embedded sensors, a map digital and key objects. The selected architecture is easily suitability for testing, since it allows you to simulate objects and sensors very close to reality / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestra em Engenharia Mecânica

Orientador: José Raimundo de Oliveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-23T02:36:38Z (GMT). No. of bitstreams: 1 Santos_MiltonFelipeSouza_M.pdf: 3219713 bytes, checksum: c54c1e303b8b3f5087f884140423e2a6 (MD5) Previous issue date: 2013 / Resumo: Este trabalho analisa as possibilidades de arquiteturas de hardware buscando encontrar uma plataforma de desenvolvimento escalável e possível de se adaptar a diferentes estruturas mecânicas de veículos móveis. Esta plataforma deve ainda ter sensores suficientes para permitir comportamentos autônomos ao veículo. Para isto, de forma a entender melhor o conceito de autonomia, primeiramente foram analisadas as capacidades mentais humanas. Das capacidades estudadas foram escolhidas as capacidades de sensação, percepção, orientação e cognição como capacidades relacionadas ao hardware quando implantadas em veículos móveis artificialmente. Em seguida cada uma destas quatro capacidades mentais foi analisada a fundo buscando métodos e sistemas para solucionar estes problemas. Foram analisadas também as possibilidades de topologias em rede de forma a conectar os módulos individuais e propostos critérios de escolha dos módulos e topologias do sistema. Após todas estas análises exaustivas, onde somente as partes mais importantes foram incluídas neste trabalho, foi escolhida a topologia de barramento serial com arbitração em hardware para permitir modularidade, escalabilidade e confiabilidade. Como barramento elétrico foi escolhido o barramento CAN (Controller Area Network) que juntamente com diversos módulos especificados neste trabalho resultam na plataforma que foi chamada "Sistema Autônomo Completo". Com base neste sistema, foram propostos como resultados duas simplificações: uma baseada em veículos que operam no solo (bidimensional) e outra para veículos que operam em ambientes tridimensionais como o ar ou a água. Buscando um enfoque educacional foi proposta uma sequência de implantação do sistema autônomo completo e alguns estudos de casos estão apresentados. Com este trabalho foi possível estruturar e criar uma sequência de desenvolvimento de um veículo móvel robótico em fases que podem ser facilmente seguidas por escolas ou empresas / Abstract: This work analyzes hardware architectures of embedded systems, searching for a development platform of mobile robots. This platform must be scalable and easily adaptable to several types of mechanical designs of mobile vehicles. And it must have enough sensors in order to reach autonomous performance. For better understanding concepts of autonomy, the human brain capacities were studied. From the studied capacities, sensation, perception, representation and orientation were chosen. These four capacities were chosen as related with hardware implementations if artificially designed for mobile vehicles. Network topologies for connecting modules of independent methods for the artificial brain capabilities mentioned were also analyzed. For choosing the best proposal, some criteria were defined for the modules and system topologies. After this analysis, where only the most important parts were included, a topology was chosen. The chosen topology is the serial bus with hardware arbitration. The chosen electrical bus was the CANbus, which together with the other modules specified in this work resulted in the platform called "Full Autonomous Vehicle". Based on this system platform, simplifications were proposed: one focused on vehicles with two-dimensional movements, and other focused on vehicles with three-dimensional movements. Searching for an educational point-of-view, an implementation sequence was proposed for the full autonomous vehicle and some cases were studied. With this work was possible to organize and create a development sequence of a robotic mobile vehicle divided by phases. These phases can be easily followed by schools and companies / Mestrado / Automação / Mestre em Engenharia Elétrica

Autonomous relative terrain navigation is a problem at the forefront of many space missions involving close proximity operations to any target body. With no definitive answer, there are many techniques to help cope with this issue using both passive and active sensors, but almost all require high fidelity models of the associated dynamics in the environment. Convolutional Neural Networks (CNNs) trained with images rendered from a digital terrain map (DTM) of the body’s surface can provide a way to side-step the issue of unknown or complex dynamics while still providing reliable autonomous navigation. This is achieved by directly mapping an image to a relative position to the target body. The portability of trained CNNs allows “offline” training that can yield a matured network capable of being loaded onto a spacecraft for real-time position acquisition. In this thesis the lunar surface is used as the proving ground for this optical navigation technique, but the methods used are not unique to the Moon, and are applicable in general.

Orientador: Pablo Siqueira Meirelles / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-26T13:45:42Z (GMT). No. of bitstreams: 1 Alvarez-Jacobo_JustoEmilio_D.pdf: 7664743 bytes, checksum: 72e7ab67912a544a9178da02711121d9 (MD5) Previous issue date: 2013 / Resumo: Este trabalho apresenta o estudo e desenvolvimento de um Sistema de Percepção baseado na utilização de sensores telemétricos tipo LIDAR. Uma plataforma de escaneamento a laser em três dimensões LMS-3D é construída a fim da navegação autônoma de robôs. A área navegável é obtida a partir de mapas telemétricos, caracterizados com algoritmos de grades de ocupação (GO) (em duas dimensões com a terceira colorida e 3D) e com o cálculo de gradientes vetoriais. Dois tipos de áreas navegáveis são caracterizadas: (i) área de navegação primária representada por uma área livre dentro da GO; e (ii) área de navegação continua representada pela soma das áreas continuas e gradientes classificados com um determinado limiar. Este limiar indica se uma área é passível de navegação considerando as características do robô. A proposta foi avaliada experimentalmente em ambiente real, contemplou a detecção de obstáculos e a identificação de descontinuidades / Abstract: This thesis was proposed to demonstrate the study and development of a Perception System based on the utilization of a LIDAR telemetric sensors. It was proposed to create a LMS-3D three dimension laser scanning platform, in an attempt to promote the Autonomous Robot Navigation. The scanned area was obtained based on telemetric maps, which was characterized with Occupancy Grid algorithms (OG) (in two dimensions with the third colored and 3D) and Vector Gradients calculation. Two different navigation areas were characterized: (i) primary area of navigation, that represents the free area inside a OG, and (ii) continuous navigation area, that represents the navigated area composed by the sum of continuous areas and the gradients classified by a determined threshold, which indicates the possible navigated area, based on the robot characteristics. The proposition of this thesis was evaluated in a real environment and was able to identify the obstacles detection and also the discontinuance / Doutorado / Mecanica dos Sólidos e Projeto Mecanico / Doutor em Engenharia Mecânica

Automated guided vehicles (AGVs) are the key equipment of flexible production systems and an important means for realizing a modern logistics system that meets the demands of Industry 4.0. AGVs are used from the mid 50th to delegate monotonous work of delivering products from the human to the automated device. In the long run, the usage of AGVs brings huge benefits to the manufacturing companies. But the purchase and installation of these devices significantly increase operational costs. This fact halts small and medium-sized enterprises from adopting this technology on their shop floors. The idea of this thesis work is to design and create a device that can be retailed at a significantly lower price without compromising flexibility and functional properties, to be used by smaller businesses. For this mater are used more affordable parts that can bring the cost down of a final product. This work describes the process of developing a differential drive mobile platform under the control of the robotic operating system. The process includes the development of a virtual model; selection of required components and investigation of their compatibility; development of chassis, suspension, and gear system; development of a hardware interface to interact with hardware components; configuration of different algorithms of control, cartography, and navigation; evaluation of the device. The research method is used in this work is design and creation due to the necessity of creating a physical prototype. The budget specification for the project was set to 50000 SEK and the desired payload capacity was set to 100kg. The work has resulted in the creation of a prototype of the AGV. The cost of the project is 20595 SEK. The evaluation of a prototype resulted in a maximum towing force of 300N. The load capacity is limited by the mobile base is 400kg. Safety sensors are not used in this project as the device was meant to operate in a controlled environment. The work also gives an evaluation of the Gmapping algorithm in case of using the laser scanner (RPlidar A1) and two algorithms of navigation stack: TrajectoryPlannerROS and DWA planner. The final prototype is evaluated to support an autonomous movement within a controlled environment.

Space travelers in science fiction can drop out of hyperspace and make a pinpoint landing on any strange new world without stopping to get their bearings, but real-life space navigation is an art characterized by limited information and complex mathematics that yield no easy answers. This study investigates, for the first time ever, what position and velocity estimation errors can be expected by a starship arriving at a distant star - specifically, a miniature probe like those proposed by the Breakthrough Starshot initiative arriving at Proxima Centauri. Such a probe consists of nothing but a small optical camera and a small microprocessor, and must therefore rely on relatively simple methods to determine its position and velocity, such as observing the angles between its destination and certain guide stars and processing them in an algorithm known as an extended Kalman filter. However, this algorithm is designed for scenarios in which the position and velocity are already known to high accuracy. This study shows that the extended Kalman filter can reliably estimate the position and velocity of the Starshot probe at speeds characteristic of current space probes, but does not attempt to model the filter’s performance at speeds characteristic of Starshot-style proposals. The gravity of the target star is also estimated using the same methods.