Omnidirectional Vision Based Topological Navigation

Goedemé T., Van Gool L., ''Omnidirectional vision based topological navigation'', Mobile robots navigation, pp. 172-196, Barrera Alejandra, ed., March 2010, InTech.status: publishe

Long-term experiments with an adaptive spherical view representation for navigation in changing environments

Real-world environments such as houses and offices change over time, meaning that a mobile robot’s map will become out of date. In this work, we introduce a method to update the reference views in a hybrid metric-topological map so that a mobile robot can continue to localize itself in a changing environment. The updating mechanism, based on the multi-store model of human memory, incorporates a spherical metric representation of the observed visual features for each node in the map, which enables the robot to estimate its heading and navigate using multi-view geometry, as well as representing the local 3D geometry of the environment. A series of experiments demonstrate the persistence performance of the proposed system in real changing environments, including analysis of the long-term stability

Ubiquitous Positioning: A Taxonomy for Location Determination on Mobile Navigation System

The location determination in obstructed area can be very challenging especially if Global Positioning System are blocked. Users will find it difficult to navigate directly on-site in such condition, especially indoor car park lot or obstructed environment. Sometimes, it needs to combine with other sensors and positioning methods in order to determine the location with more intelligent, reliable and ubiquity. By using ubiquitous positioning in mobile navigation system, it is a promising ubiquitous location technique in a mobile phone since as it is a familiar personal electronic device for many people. However, as research on ubiquitous positioning systems goes beyond basic methods there is an increasing need for better comparison of proposed ubiquitous positioning systems. System developers are also lacking of good frameworks for understanding different options during building ubiquitous positioning systems. This paper proposes taxonomy to address both of these problems. The proposed taxonomy has been constructed from a literature study of papers and articles on positioning estimation that can be used to determine location everywhere on mobile navigation system. For researchers the taxonomy can also be used as an aid for scoping out future research in the area of ubiquitous positioning.Comment: 15 Pages, 3 figure

A 3D Data Acquisition Cart with Applications to Warehouse Automation

Automated Guided Vehicles (AGV) are increasingly being adopted for warehouse automation. This work focuses on the design and fabrication of a 3D Data Acquisition Cart (3D-DAC) with applications to warehouse automation. The 3D-DAC facilitates acquiring large scale data sets without the overhead of requiring an AGV. It integrates on-board computing and power, optical wheel encoders, and a Velodyne VLP-16 Puck LiDAR for exteroceptive sensing. Three-dimensional (3D) LiDARs like the Velodyne Puck are becoming the sensor of choice for not only robot navigation, but also for other tasks such as pallet detection and picking and dropping to name but a few. In this thesis, we demonstrated real-time mobile data logging with the 3D-DAC. Results were validated in a Simultaneous Localization and Mapping (SLAM) task. Preliminary results indicate the potential to map warehouses on the order of 10,000 square meters with an accuracy of several centimeters

Augmented indoor hybrid maps using catadioptric vision

En este Trabajo de Fin de Máster se presenta un nuevo método para crear mapas semánticos a partir de secuencias de imágenes omnidireccionales. El objetivo es diseñar el nivel superior de un mapa jerárquico: mapa semántico o mapa topológico aumentado, aprovechando y adaptando este tipo de cámaras. La segmentación de la secuencia de imágenes se realiza distinguiendo entre Lugares y Transiciones, poniendo especial énfasis en la detección de estas Transiciones ya que aportan una información muy útil e importante al mapa. Dentro de los Lugares se hace una clasificación más detallada entre pasillos y habitaciones de distintos tipos. Y dentro de las Transiciones distinguiremos entre puertas, jambas, escaleras y ascensores, que son los principales tipos de Transiciones que aparecen en escenarios de interior. Para la segmentación del espacio en estos tipos de áreas se han utilizado solo descriptores de imagen globales, en concreto Gist. La gran ventaja de usar este tipo de descriptores es la mayor eficiencia y compacidad frente al uso de descriptores locales. Además para mantener la consistencia espacio-temporal de la secuencia de imágenes, se hace uso de un modelo probabilístico: Modelo Oculto de Markov (HMM). A pesar de la simplicidad del método, los resultados muestran cómo es capaz de realizar una segmentación de la secuencia de imágenes en clusters con significado para las personas. Todos los experimentos se han llevado a cabo utilizando nuestro nuevo data set de imágenes omnidireccionales, capturado con una cámara montada en un casco, por lo que la secuencia sigue el movimiento de una persona durante su desplazamiento dentro de un edificio. El data set se encuentra público en Internet para que pueda ser utilizado en otras investigaciones

Mobile robot map building from time-of-flight camera

A map building algorithm for mobile robots is introduced in this paper. The perceived environment is represented in a map containing in each cell a probability of presence of an object or part of an object. The environment is represented as a collection of modular occupancy grids which are added to the map as far as the mobile robot finds objects outside the existing grids. In this approach a time-of-flight (ToF) camera is exploited as a range sensor for mapping. Indeed, one of the areas where ToF sensors are adequate is in obstacle avoidance, because the detection region is not only horizontal but also vertical, allowing to detect obstacles with complex shapes. The main steps of the map building algorithm are extensively described in the paper. The results of testing the algorithm are considered in two different indoor environments