Where am I? Sensors and Methods for Mobile Robot Positioning

162 Part II Systems and Methods for Mobile Robot Positioning
Figure 6.13: Front view of the Joy 16CM continuous mining machine at the U.S. Bureau of
Mines' test facility. Cylindrical retroreflective targets are mounted on the tail (Courtesy of
Anderson [1991].)
Besides the above mentioned
technical difficulties the LaserNet
system provided accurate data. In
a series of test in which the CM
moved on average one meter
(3.3 ft) forward while cutting coal
at the same time the resulting average
error in translation was well
below one centimeter. In a series
of rotational movements of 7 to
15( the average measurement
error was 0.3(. It should be emphasized
that the LaserNet system
proved robust in the presence of
substantial vibrations.
Figure 6.13: Schematic view of the Joy 16CM with two retroreflective
targets and two LaserNav beacons/sensors in the entryway. (Courtesy
of Anderson, [1991].)