Page 26 - Autonomous Mobile Robots

10 Autonomous Mobile Robots

FIGURE 1.1 A selection of images captured with an IR camera. The temperature of sur-
faces gives an alternative and complementary method of scene classification compared
to standard imaging. Note the severe lens distortion.

and there are restrictions on their purchase. However, it is now possible to
installcommercialnight-visionsystemsonroadvehicles: GeneralMotorsoffers
a thermal imaging system with head-up display (HUD) as an option on the
Cadillac DeVille. The obvious application for IR cameras is in night driving but
they are useful in daylight too, as they offer an alternative (or complementary)
way of segmenting scenes based on temperature levels.
Catadioptric cameras. In recent years we have witnessed the increasing
1
use of catadioptric cameras. These devices, also referred to as omnidirec-
tional, are able to view a complete hemisphere with the use of a parabolic
mirror [8]. Practically, they work well in structured environments due to the
way straight lines project to circles. Bosse [9] uses them indoors and outdoors
and tracks the location of vanishing points in a structure from motion (SFM)
scheme.

1.2.1.2 Active sensors
A brief glimpse through robotics conference proceedings is enough to demon-
strate just how popular and useful laser scanning devices, such as the ubiquitous
SICK, are in mobile robotics. These devices are known as LADAR and are

1 Combining reflection and refraction; that is, a mirror and lens.

© 2006 by Taylor & Francis Group, LLC

FRANKL: “dk6033_c001” — 2006/3/31 — 16:42 — page 10 — #10