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The scanning rangefinder must be rotated (or translated) to acquire a
3D data set. To rotate the device, we attached it to a pan-tilt unit
(model PTU-46-70) from Directed Perception, Inc (see
http://www.DPerception.com for more information). We do not require
the tilt operation for our task, and fortunately it can be disabled.
The panning unit attaches to a computer with a standard serial cable.
The panning unit has a claimed position resolution of 0.771 arc
minutes, allowing us to make nearly 80 scans per degree. We chose
this model over the 46-17.5 for the higher positional resolution. It
also has the advantage of more power and slower velocity since lower
gearing is used. The pan-tilt unit is very easy to interface to.
The rangefinder with the scanning mirror and pan-tilt unit are all
shown in figure 5.
Lars S. Nyland