The Hokuyo URG-04LX laser range finder is pretty popular, and today I noticed someone was wondering where the optical center is. Well it turns out that there are actually two optical planes, one for transmit and one for receive. Since the alternative is probably dealing with non-euclidean geometry, for my robots I generally use the average between the two as the optical center and then this assumption gets wrapped up in the error term. I found this information somewhere on Hokuyo's website in their password protected customer area.
As an added bonus here is a 3D cad model (right click save as) of the Hokuyo URG-04LX Laser ranger in STEP Format. The CAD model and other measures is not guaranteed to be accurate.
Caveat Emptor.
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2 comments:
I like this rotating mechanism. Can you provide some detail about the implementation? Is that a Maxon motor? Can you provide some info about the encoder? Have you gotten a good 3D point cloud off of this sensor?
I'm currently using a Swiss Ranger, and its narrow field of view is giving me problems in a current application. It also suffers from IR glare spots and I'm using it around a lot of stainless steel. This rotating laser looks like a promising alternative.
At this point, I would suggest using one of the many robotics servos available these days. They have a lower backlash than you are likely to obtain by building a rotation mechanism yourself.
http://www.hitecrcd.com/products/servos/robotics/index.html
The only other thing to notice is that there are two optical centers. One for transmit and one for receive.
You can get better results from the SwissRanger by using the confidence information returned by the sensor to filter the data. You can also try filtering the SwissRanger point cloud based on the reflectivity.
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