M.Sc Thesis | |

M.Sc Student | Livshitz Dmitry |
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Subject | Robotic Self Location Using Three Dimensional Fiducials and Omnidirectional Cameras |

Department | Department of Computer Science |

Supervisor | PROF. Alfred Bruckstein |

This project presents a robot navigation system
designated for testing a novel approach to self-location. The system consists
of a mobile robot with a parabolic camera mounted on and a PC Workstation
carrying out the computations. The parabolic camera provides the navigation
system with full 360° field of view images which serve as a feedback for a robot
trajectory correction. A robot self-location procedure uses a number of
specially designed locating objects called *fiducials* to determine the
robot position. The proposed *fiducials* are covered with a three
dimensional pattern which makes possible the pose-estimation without complex 3D
reconstruction methods as the currently available approaches require. The main
idea is that if an observer looks at such a *fiducial* from some unknown
angle he can easily figure out what this angle is. The only thing to do is to
calculate the average amount of light from the *fiducial* reaching the
observer. In terms of image processing this implies calculating an average
grayscale value over the *fiducial* in a picture taken by the observer.
Having at least two *fiducials* at his disposal the observer, therefore,
knows the angles at which he sees them and can estimate his position. In addition,
a single panoramic image obtained from the camera contains a complete scene of
the robot environment along with all of the *fiducials.* This feature of
panoramic images introduces further simplification into the self-location
algorithm. Some experiments were conducted and the corresponding estimation
results are presented. A shape of a mirror which maximizes the *fiducials’*
resolution on the image plane was calculated. Such a mirror is optimal for the
presented pose estimation algorithm and can be used to enlarge the robot working
area.