Jacobiano de la Imagen para un Par Estereoscópico de Cámaras: Comparativa entre el Analítico y el Estimado Incorporando la Restricción Epipolar

Este artículo describe un estudio comparativo del comportamiento del Jacobiano estimado de la imagen que incorpora la geometrÃía epipolar del sistema de dos cámaras, frente al bien conocido método del Jacobiano analÃítico que es utilizado por la mayorí

Estudio comparativo de planificadores de trayectorias en servo control visual

Durante la implementación y desarrollo de algoritmos de servo control visual a menudo se considera la planificación de trayectorias principalmente en dos esquemas: cuando el control se basa en el espacio de la imagen o cuando se trata de trayectorias punto a punto del robot. En el presente artículo se plantea la planificación de trayectorias para tareas de seguimiento, utilizando una arquitectura de control servo visual basado en posición bajo la concepción de mirar y mover dinámico. En esta arquitectura el lazo visual es más lento que el control articular. Por esta razón se propone suavizar los estados intermedios del lazo articular por medio de un planificador específicamente diseñado para tareas de seguimiento. En el planificador de trayectorias propuesto se toman en cuenta las máximas prestaciones del robot y sus elementos así como garantizar la suavidad durante el seguimiento. Se realiza una comparativa con un planificador del tipo polinómico que asegura también prestaciones deseadas. El problema que aquí se plantea se desarrolla y experimenta en un sistema de pruebas especialmente diseñado para realizar pruebas e implementaciones de estrategias y algoritmos de control visual y articular. Este sistema de pruebas está principalmente compuesto por un robot paralelo de 3 GDL y un sistema de visió

Image Based Visual Servoing: Estimated Image Jacobian by Using Fundamental Matrix VS Analytic Jacobian

This paper describes a comparative study of performance between the estimated image Jacobian that come from taking into account the geometry epipolar of a system of two cameras, and the well known analytic image Jacobian that is utilized for most applications in visual servoing. Image Based Visual Servoing architecture is used for controlling a 3 d.o.f. articular system using two cameras in eye to hand configuration. Tests in static and dynamic cases were carried out, and showed that the performance of estimated Jacobian by using the properties of the epipolar geometry is such as good and robust against noise as the analytic Jacobian. This fact is considered as an advantage because the estimated Jacobian does not need laborious previous work prior the control task in contrast to the analytic Jacobian does

Jacobiano de la Imagen para un Par Estereoscópico de Cámaras: Comparativa entre el Analítico y el Estimado Incorporando la Geometría Epipolar

El presente artículo describe un estudio comparativo entre el comportamiento del Jacobiano calculado de forma analítica y el estimado, incorporando la geometría epipolar, cuando se utiliza un sistema con dos cámaras. La arquitectura de control utilizada es Control Visual Basado en Imagen controlándose un sistema articular de tres g.d.l. utilizando dos cámaras en configuración cámara fija. Se realizaron pruebas tanto en caso estático como en caso dinámico, las cuales mostraron que el método de estimación del Jacobiano que utiliza las propiedades de la geometría epipolar es tan bueno y robusto frente al ruido como el Jacobiano analítico. Esto es considerado como una ventaja, puesto que el Jacobiano estimado no necesita un laborioso trabajo previo como el analítico

Dynamic Visual Servoing for Ping-Pong Game of a 3DOF PKM

This article describes the new visual servo control and strategies that are utilized to carry out dynamic tasks by the system Robotenis. This platform is a parallel robot that is equipped with an acquisition and processing system of visual information. Its main feature is that it has a completely open architecture control, planned in order to design, implement, test and compare control strategies and algorithms (visual and actuated joint controllers). Following sections describe a new visual control strategy specially designed to track dynamic objects in 3D space. Contrasting the strategies shown in previous works, where the end effect or of the robot keeps a constant distance from the tracked object, in this work the controller is specially designed in order to allow changes the tracking reference. Changes in the tracking reference can be utilized to grip an object that is under movement or as in this case, Ping-Pong playing. Lyapunov stability is taken into account in the controller design

A Comparative Study between Analytic and Estimated Image Jacobian by Using a Stereoscopic System of Cameras

This paper describes a comparative study of performance between the estimated image Jacobian that come from taking into account the epipolar geometry in a system of two cameras, and the well known analytic image Jacobian that is utilized for most applications in visual servoing. Image Based Visual Servoing architecture is used for controlling a 3 DOF articular system using two cameras in eye to hand configuration. Tests in static and dynamic cases were carried out, and showed that the performance of estimated Jacobian by using the properties of the epipolar geometry is such as good and robust against noise as the analytic Jacobian. This fact is considered as an advantage because the estimated Jacobian does not need laborious previous work prior to control task in contrast to the analytic Jacobian does

Homography-Based Tracking Control for Mobile Robots

This work presents a control strategy that allows a follower robot to track a target vehicle moving along an unknown trajectory with unknown velocity. It uses only artificial vision to establish both the robot’s position and orientation relative to the target. The control system is proved to be asymptotically stable at the equilibrium point, which corresponds to the navigation objective. Experimental results with two robots, a leader and a follower, are included to show the performance of the proposed vision-based tracking control system

Estimation of the rigid transformation between two cameras from the Fundamental Matrix VS from Homographies.

The 3D reconstruction is an important step for the analytical calculation of the Jacobian of the image in a process of visual control of robots. In a two-camera stereo system that reconstruction depends on the knowledge of the rigid transformation between the two cameras and is represented by the rotation and translation between them. These two parameters are the result of a calibration of the stereo pair, but can also be retrieved from the epipolar geometry of the system, or from a homography obtained by features belonging to a flat object in the scene. In this paper, we make an assessment of the latter two alternatives, taking as reference an Euclidean reconstruction eliminating image distortion. We analyze three cases: the distortion inherent in the camera is corrected, without corrected distortion, and when Gaussian noise is added to the detection of features

Vision-Based Control of the Robotenis System

In this paper a visual servoing architecture based on a parallel robot for the tracking of faster moving objects with unknown trajectories is proposed. The control strategy is based on the prediction of the future position and velocity of the moving object. The synthesis of the predictive control law is based on the compensation of the delay introduced by the vision system. Demonstrating by experiments, the high-speed parallel robot system has good performance in the implementation of visual control strategies with high temporary requirement