Control visual basado en flujo de movimiento

Este artículo describe una nueva técnica para el seguimiento de trayectorias empleando control basado en imagen denominada control visual basado en flujo de movimiento. Esta estrategia permite el seguimiento de trayectorias especificadas en el espacio de la imagen presentando asimismo un correcto desempeño en el espacio cartesiano 3-D. Una de las principales aportaciones conseguidas con la aplicación de control visual basado en flujo de movimiento es la posibilidad de realizar el seguimiento de forma no dependiente del tiempo, lo que permite asegurar un correcto seguimiento de la trayectoria en la imagen al no verse el sistema sometido a restricciones temporales

Movement flow-based visual servoing to track moving objects

The purpose of this paper is to describe a new method for tracking trajectories specified in the image space. This method, called movement flow-based visual servoing system, is applied to an eye-in-hand robot and it is shown that it allows the correct tracking of a trajectory, not only in the image but also in the 3-D space. This method is also extended to the case in which the object from which the features are extracted, is in motion. To do so, the estimations obtained, using several Kalman filters, are integrated in the control action

Time independent tracking using 2-D movement flow-based visual servoing

In this paper, the so-called 2-D movement flowbased visual servoing system is proposed, which allows the tracking of trajectories planned in the image space. This method is time-independent, which is useful when problems such as obstructions occur during the tracking. This method allows the tracking of image trajectories assuring the correct behaviour in the 3-D space and avoiding the limitations of the time-dependent systems used up to now for tracking trajectories. This aspect has allowed its application to manipulation tasks in which the trajectory can be obstructed during the tracking.This work is partially supported by the Spanish MCYT project “DESAURO: Desensamblado Automático Selectivo para Reciclado mediante Robots Cooperativos y Sistema Multisensorial” (DPI2002-02103)

Analysis and adaptation of integration time in PMD camera for visual servoing

The depth perception in the objects of a scene can be useful for tracking or applying visual servoing in mobile systems. 3D time-of-flight (ToF) cameras provide range images which give measurements in real time to improve these types of tasks. However, the distance computed from these range images is very changing with the integration time parameter. This paper presents an analysis for the online adaptation of integration time of ToF cameras. This online adaptation is necessary in order to capture the images in the best condition irrespective of the changes of distance (between camera and objects) caused by its movement when the camera is mounted on a robotic arm.This work is supported by the Spanish Ministry of Education and Science (MEC) through the research project DPI2008-02647, “Manipulación Inteligente mediante percepción háptica y control visual empleando una estructura articular ubidada en el robot manipulador”

Sistema automático de verificación de tareas de desensamblado

La demanda actual de reciclaje lleva consigo la necesidad de desarrollo de sistemas de desensamblado automático. Estos sistemas requieren la presencia de un elemento verificador que determine si el proceso se realiza según lo previsto o si, por lo contrario, es necesaria una rectificación del proceso de desensamblado. Este artículo realiza una descripción de los distintos componentes de un sistema encargado de realizar la verificación de un sistema de desensamblado automático. Se muestra un modelo del sistema basado en diferentes niveles de Redes de Petri que capta con sucesivo nivel de “granularidad” las acciones a realizar por el sistema de verificación. Estas acciones, a menudo compuestas de procesamientos de imágenes, también habrán de determinar la localización del sistema de visión para captar suficiente información del entorno para determinar si el proceso de desensamblado se realiza de forma correcta

A detection method of intersections for determining overlapping using active vision

Sometimes, the presence of objects difficult the observation of other neighboring objects. This is because part of the surface of an object occludes partially the surface of another, increasing the complexitiy in the recognition process. Therefore, the information which is acquired from scene to describe the objects is often incomplete and depends a great deal on the view point of the observation. Thus, when any real scene is observed, the regions and the boundaries which delimit and dissociate objects from others are not perceived easily. In this paper, a method to discern objects from others, delimiting where the surface of each object begins and finishes is presented. Really, here, we look for detecting the overlapping and occlusion zones of two or more objects which interact among each other in a same scene. This is very useful, on the one hand, to distinguish some objects from others when the features like texture colour and geometric form are not sufficient to separate them with a segmentation process. On the other hand, it is also important to identify occluded zones without a previous knowledge of the type of objects which are wished to recognize. The proposed approach is based on the detection of occluded zones by means of structured light patterns projected on the object surfaces in a scene. These light patterns determine certain discontinuities of the beam projections when they hit against the surfaces becoming deformed themselves. So that, such discontinuities are taken like zones of boundary of occlusion candidate regions

Automatic detection of specular reflectance in colour images using the MS diagram

In this paper we present a new method for the identification of specular reflectance in colour images. We have developed a bi-dimensional histogram which allows the exploitation of the relations between the signals of intensity and saturation of a colour image. Once the diagram has been constructed, it is possible to verify that the pixels of the specular reflectance are located in a well-defined region. The brightness is automatically identified by means of the extraction of pixels present in this region of the diagram, independently of their hue values. The effectiveness of the method in a variety of real chromatic images has been proven

Tecnologías en la inteligencia ambiental

En este artículo se presenta el término “Inteligencia Ambiental” (AmI) y se describen las distintas tecnologías que posibilitan su desarrollo: la computación ubicua, la comunicación ubicua y las interfaces inteligentes. Enumeraremos las distintas técnicas de localización que se usan en los entornos inteligentes para determinar la ubicación del usuario y poder ofrecerle así los servicios más adecuados. Para comprender mejor las posibilidades de la AmI, también mostraremos sus principales áreas de aplicación.Este trabajo ha sido financiado por el Ministerio de Educación y Ciencia (MEC) de España mediante el proyecto DPI2005-06222 “Diseño, Implementación y Experimentación de Escenarios de Manipulación Inteligentes para Aplicaciones de Ensamblado y Desensamblado Automático” y mediante la beca de postgrado FPU AP2005-1458

Safe human-robot interaction based on dynamic sphere-swept line bounding volumes

This paper presents a geometric representation for human operators and robotic manipulators, which cooperate in the development of flexible tasks. The main goal of this representation is the implementation of real-time proximity queries, which are used by safety strategies for avoiding dangerous collisions between humans and robotic manipulators. This representation is composed of a set of bounding volumes based on swept-sphere line primitives, which encapsulate their links more precisely than previous sphere-based models. The radius of each bounding volume does not only represent the size of the encapsulated link, but it also includes an estimation of its motion. The radii of these dynamic bounding volumes are obtained from an algorithm which computes the linear velocity of each link. This algorithm has been implemented for the development of a safety strategy in a real human–robot interaction task.This work is funded by the Spanish Ministry of Education and the Spanish Ministry of Science and Innovation through the projects DPI2005-06222 and DPI2008-02647 and the grant AP2005-1458

Detection of partial occlusions of assembled components to simplify the disassembly tasks

An automatic disassembly cell requires of a computer vision system for recognition and localization of the products and each of theirs components. The detection of occlusions adds more information to the knowledge base to identify components and products, and generate a trustworthy and precise relational model (generic graph of hierarchic relations among the different components that make up the product). In this paper, a method to detect partial occlusions in assembled components is presented. This method is based on the fusion of regions and edges information, and it offers a certain degree of simplification for the recognition and modelled of the disassembly tasks, of the set of components which compose the product. The proposed approach to detect regions is a hybrid approach between RGB and HSV spaces. The bi-dimensional histogram V/S is employed for the selection of the appropriate thresholds which serve as an aid to diminish the influence of the highlights and shadows in images. The goal of this paper is to present an approach for the detection of occlusions in assembled components from a combination of HSV and RGB spaces, a bi-dimensional histogram and an edge detector.This work was funded by the following Spanish MCYT project “DESAURO: Desensamblado Automático Selectivo para Reciclado mediante Robots Cooperativos y Sistema Multisensorial” (MCYT (DPI2002-02103)