Where am I? Sensors and Methods for Mobile Robot Positioning

Chapter 4: Sensors for Map-Based Positioning 117
Center of
rotation
Reflected
light back
Mirror
Light
out
Lens
Motor
LED
Lens
Detector
6.0" max.
Figure 4.24: Schematic drawing of the ORS-1 ranging
system. (Courtesy of ESP Technologies, Inc.)
coverage. It is driven at 1 to 2 rps by a motor fitted
with an integral incremental encoder and an optical
indexing sensor that signals the completion of each
revolution. The system is capable of simultaneous
operation as a wideband optical communication
receiver [Miller and Wagner, 1987].
Figure 4.25: The ORS-1 ranging system.
(Courtesy of ESP Technologies, Inc.)
4.2.3 Acuity Research AccuRange 3000
Acuity Research, Inc., [ACUITY],
Menlo Park, CA, has recently introduced
an interesting product capable of
acquiring unambiguous range data from
0 to 20 meters (0 to 66 ft) using a proprietary
technique similar to conventional
phase-shift measurement (see
Tab. 4.11). The AccuRange 3000 (see
Figure 4.26) projects a collimated beam
of near-infrared or visible laser light,
amplitude modulated with a non-sinusoidal
waveform at a 50-percent duty
cycle. A 63.6-millimeter (2.5 in) collection
aperture surrounding the laser diode
emitter on the front face of the
cylindrical housing gathers any reflected
energy returning from the target, and
Figure 4.26: The AccuRange 3000 distance measuring
sensor provides a square-wave output that varies inversely in
frequency as a function of range. (Courtesy of Acuity Research,
Inc.)