Wednesday, May 30, 2012

Taking a different approach to 3D


I don’t have any hard numbers but it’s my impression that laser triangulation is the number one method for 3D machine vision, probably followed by stereo vision and then time-of-flight methods. However, smart people at the Fraunhofer Institute have come up with a different approach: what about time-of-flight laser scanning, they asked.

Now I’m not 100% sure that’s what they’re doing, but according to “3-Dimensional laser scanner boosts rail safety” on the Optics.org website (May 23rd, 2012,) “Heinrich Höfler explains: “We send off a laser beam and wait until it returns. We measure the time in between and that tells us how far away the object is…”

So I think that’s time of flight.

Details of the technology are sketchy, (the Fraunhofer tends to be shy about its intellectual property,) but it appears they’ve developed an eye-safe, high-speed laser scanning system.

The “eye-safe” claim I’m a little skeptical about, I must confess. The report says, “To make the scanner safe for the human eye, the researchers had to develop a new wavelength range around infrared, which is eyesafe.” But my understanding is that while the human eye can’t see IR light, it can still be damaged by it, out to 900nm, if not more. Please let me know if I’m wrong.

But on the other hand, if they really have a 3D scanner that’s fast and safe I have a number of applications in mind for it.

1 comment:

Anonymous said...

"Laser TOF camera" is called Lidar:

http://velodynelidar.com/lidar/lidar.aspx

http://hds.leica-geosystems.com/en/Leica-ScanStation-C10_79411.htm

And industrial line scan model:

https://mysick.com/partnerPortal/ProductCatalog/DataSheet.aspx?ProductID=33774#