Raquel Frizera Vassallo

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Computing a camera's ego-motion from an image sequence is easier to accomplish when a spherical retina is used, as opposed to a standard retinal plane. On a spherical field of view both the focus of expansion and contraction are visible, whereas for a planar retina that is not necessarily the case. Recent research has shown that omnidirectional systems can(More)
We address the problem of visual-based indoors navigation based on a single camera that provides the required visual feedback information. The usual approach relies on a map to relocate the robot with respect to the environment. Once the robot position and orientation are known, a suitable trajectory is deened according to the mission goals and the(More)
We address the problem of visual-based navigation of a mobile robot in indoors environments. The robot control system is based on a single camera to provide the required visual feedback information. The control strategy merges two distinct paradigms that appeared recently in the technical literature, in order to provide the robustness and computation speed(More)
We propose the use of motor vocabulary, that express a robot's specific motor capabilities, for topological map-building and navigation. First, the motor vocabulary is created automatically through an imitation behaviour where the robot learns about its own motor repertoire, by following a tutor and associating its own motion perception to motor words. The(More)
— In this work a robot cooperation strategy based on omnidirectional vision is presented. Such strategy will be applied to a mobile robot team formed by small and simple robots and a bigger leader robot with more computational power. The leader must control team formation. It has an omnidirectional camera and sees the other robots. Color segmentation and(More)
This paper describes an intelligent space, whose objective is to localize and control robots or robotic wheelchairs to help people. Such an intelligent space has 11 cameras distributed in two laboratories and a corridor. The cameras are fixed in the environment, and image capturing is done synchronously. The system was programmed as a client/server with(More)
This paper presents a novel control algorithm and visual measurement for the autonomous navigation of a non-holonomic robot team while preserving a specified formation. The control errors are defined relative to the leader robot of the team in terms of the actual position of each robot and its desired position in the formation. The stability analysis as(More)
This work reports the development and prototyping of an autonomous wheeled mobile robot. In order to guarantee this autonomy, the prototype robot is equipped with five types of sensors, which are shaft encoders, ultrasonic transducers , infrared proximity sensors, contact sensors and mo-nocular vision. These sensors interact among themselves to get accurate(More)