Page 263 - Innovations in Intelligent Machines

256 J. Gaspar et al.

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Fig. 16. A real world experiment combining Visual Path Following for door tra-
versal and Topological Navigation for long-distance goals. Odometry results before
(a) and after (b) the addition of ground truth measurements

robot heading is easily specified by clicking on the desired direction of travel in
the panoramic image, and the desired (x, y) locations are specified by clicking
in the bird’s-eye view.
Using 3D models further improves the visualization of the scene. A unique
feature of such a representation is that the user can tell the robot to arrive to
a given destination at a certain orientation simply by rotating the 3D model.
Beyond the benefits of immersion, it allows to group the information of many
views and get a global view of the environment.
In order to build the 3D scene models, we propose Interactive Scene Recon-
struction, a method based on the complimentary nature of Human and Robot
perceptions. While Humans have an immediate qualitative understanding of
the scene encompassing co-planarity and co-linearity properties of a number
of points of the scene, Robots equipped with omnidirectional cameras can take
precise azimuthal and elevation measurements.
Interactive scene reconstruction has recently drawn lots of attention.
Debevec et al in [22], propose an interactive scene reconstruction approach
for modelling and rendering architectural scenes. They derive a geometric
model combining edge lines observed in the images with geometrical proper-
ties known a priori. This approach is advantageous relative to building a CAD
model from scratch, as some information comes directly from the images. In
addition, it is simpler than a conventional structure from motion problem
because, instead of reconstructing points, it deals with reconstructing scene
parameters, which is a much lower dimension and better conditioned problem.