422 research outputs found

    Appearance-based localization for mobile robots using digital zoom and visual compass

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    This paper describes a localization system for mobile robots moving in dynamic indoor environments, which uses probabilistic integration of visual appearance and odometry information. The approach is based on a novel image matching algorithm for appearance-based place recognition that integrates digital zooming, to extend the area of application, and a visual compass. Ambiguous information used for recognizing places is resolved with multiple hypothesis tracking and a selection procedure inspired by Markov localization. This enables the system to deal with perceptual aliasing or absence of reliable sensor data. It has been implemented on a robot operating in an office scenario and the robustness of the approach demonstrated experimentally

    Global Appearance Applied to Visual Map Building and Path Estimation Using Multiscale Analysis

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    In this work we present a topological map building and localization system for mobile robots based on global appearance of visual information. We include a comparison and analysis of global-appearance techniques applied to wide-angle scenes in retrieval tasks. Next, we define multiscale analysis, which permits improving the association between images and extracting topological distances. Then, a topological map-building algorithm is proposed. At first, the algorithm has information only of some isolated positions of the navigation area in the form of nodes. Each node is composed of a collection of images that covers the complete field of view from a certain position. The algorithm solves the node retrieval and estimates their spatial arrangement. With these aims, it uses the visual information captured along some routes that cover the navigation area. As a result, the algorithm builds a graph that reflects the distribution and adjacency relations between nodes (map). After the map building, we also propose a route path estimation system. This algorithm takes advantage of the multiscale analysis. The accuracy in the pose estimation is not reduced to the nodes locations but also to intermediate positions between them. The algorithms have been tested using two different databases captured in real indoor environments under dynamic conditions

    Advances towards behaviour-based indoor robotic exploration

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    215 p.The main contributions of this research work remain in object recognition by computer vision, by one side, and in robot localisation and mapping by the other. The first contribution area of the research address object recognition in mobile robots. In this area, door handle recognition is of great importance, as it help the robot to identify doors in places where the camera is not able to view the whole door. In this research, a new two step algorithm is presented based on feature extraction that aimed at improving the extracted features to reduce the superfluous keypoints to be compared at the same time that it increased its efficiency by improving accuracy and reducing the computational time. Opposite to segmentation based paradigms, the feature extraction based two-step method can easily be generalized to other types of handles or even more, to other type of objects such as road signals. Experiments have shown very good accuracy when tested in real environments with different kind of door handles. With respect to the second contribution, a new technique to construct a topological map during the exploration phase a robot would perform on an unseen office-like environment is presented. Firstly a preliminary approach proposed to merge the Markovian localisation in a distributed system, which requires low storage and computational resources and is adequate to be applied in dynamic environments. In the same area, a second contribution to terrain inspection level behaviour based navigation concerned to the development of an automatic mapping method for acquiring the procedural topological map. The new approach is based on a typicality test called INCA to perform the so called loop-closing action. The method was integrated in a behaviour-based control architecture and tested in both, simulated and real robot/environment system. The developed system proved to be useful also for localisation purpose

    Mobile Robots Navigation

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    Mobile robots navigation includes different interrelated activities: (i) perception, as obtaining and interpreting sensory information; (ii) exploration, as the strategy that guides the robot to select the next direction to go; (iii) mapping, involving the construction of a spatial representation by using the sensory information perceived; (iv) localization, as the strategy to estimate the robot position within the spatial map; (v) path planning, as the strategy to find a path towards a goal location being optimal or not; and (vi) path execution, where motor actions are determined and adapted to environmental changes. The book addresses those activities by integrating results from the research work of several authors all over the world. Research cases are documented in 32 chapters organized within 7 categories next described

    Software architecture for self-driving navigation

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    Mención Internacional en el título de doctorThis dissertation is based on the development of the navigation software architecture for self-driving vehicles. The goal is very wide in terms of multidisciplinary fields over the different solutions provided, however, functional solutions for the implementation according to the software architecture has been proved and tested in the real research platform iCab (Intelligent Campus Automobile). The problems that the autonomous vehicles have to face are based accordingly as the three questions of navigation that each vehicle has to ask: Where am I, where should I go, and how can I go there. These questions are followed by the corresponding modules to solve that are divided into localization, planning, mapping, perception and control in addition to multitasking allocation, communication and Human-Machine Interaction. One more module is the self-awareness which is an optimal solution for detecting problems in the earliest stage. Throughout this document, the solution provided in form of a complete architecture for navigation describes the modules involved and the importance of software connections between them, generation of trajectories, mapping, localization and low level control. Finally, the results section describes scenarios and vehicle/software performance in terms of CPU for each module involved and the generation of trajectories, maps and control commands needed to move the vehicle from one point to another.Este documento es el resultado de cinco años de trabajo en el campo de los vehículos sin conductor donde, en el, se recoge el desarrollo de una arquitectura software de control para la navegación de este tipo de vehículos. El objetivo es muy ambicioso ya que para su desarrollo ha sido necesario el conocimiento de múltiples disciplinas como ingeniería electrónica, ingeniería informática, ingeniería de control, procesamiento de señales, mecánica y visión por computador. A pesar del vasto conocimiento necesario para lograr un vehículo funcional, se han alcanzado soluciones para cada uno de los problemas en que consiste la navegación autónoma, generando un vehículo autogobernado que toma decisiones por si mismo para evitar obstáculos y alcanzar los puntos de destino deseados. Los problemas principales que los vehículos autónomos tienen que hacer frente, están basados en tres preguntas principales: donde estoy, donde tengo que ir y como voy. Para responder a estas tres preguntas se ha dividido la arquitectura en los módulos siguientes: localización, planificación, mapeado del entorno y control junto con módulos extra para dotar al sistema de mas aptitudes y mejor funcionamiento como por ejemplo la comunicación entre vehículos, peatones e infraestructuras, la interacción humano máquina, la gestión de tareas con múltiples vehículos o la propia consciencia del vehículo en cuanto a su estado de baterías, mantenimiento, sensores conectados o desconectados, etc. A través de este documento, la solución proporcionada a cada uno de los módulos involucrados refleja la importancia de las conexiones de software y la comunicación entre procesos dentro de la arquitectura ya sea para la generación de trayectorias, la creación de los mapas a tiempo, la localización precisa en el entorno, o los comandos generados para gobernar el vehículo. Así mismo, en el apartado de resultados se pone de manifiesto la importancia de cumplir los plazos de compartición de mensajes y optimizar el sistema para no sobrecargar la CPU.Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Felipe Jiménez Alonso.- Secretario: Agapito Ismael Ledezma Espino.- Vocal: Alessio Malizi
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