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4.4 Augmented reality stereoscopic visualization
for intuitive robot teleguide
The paper of Livatino et al. [13] proposes a methodology for fusion of
laser and visual data in a teleoperation interface. This methodology
exploits augmented reality to realize a coherent and intuitive visualiza-
tion of integrated data, and uses stereoscopy to increase teleoperation
efficiency.
The interface presented in this work represents laser data as virtual
overlays on the video images received by the robot cameras. Three
different kinds of virtual overlays are used:
• proximity planes, semi-transparent colored layers superimposed
on the objects within the scene (figure 20a);
• rays, colored lines departing approximately from the camera po-
sition and reaching the closest objects (figure 20b);
• distance values, indications of the absolute distance between the
robot and the objects (figure 20b).
The virtual overlays have a different color depending on the distance
between the robot and the real objects to which they correspond. Red
overlays correspond to the nearest objects, yellow overlays to objects
at medium distances, green overlays to the furthest objects.
The laser measures are linearly mapped to image pixels between the
left and the right margin of the image. A semi-automatic calibration
permits to the user to adjust the first and the last mapped angles. Then,
edge detection is executed on the image in order to individuate the
bases of the objects in the image (by taking the first edge pixels from
the bottom of the image) and to vertically align the virtual overlays
with the real objects.
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