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A Mobile Robot For Modeling The World In 3D
Roland Piquepaille writes "A German team from Fraunhofer AIS has coupled a fast autonomous robot with a 3D laser scanner to digitize the environment. The team reports about their work in this article, one of fifteen on the subject of machine perception published by ERCIM News. "Kurt3D is an autonomous mobile robot equipped with a reliable and precise 3D laser scanner that digitalizes environments. High quality geometric 3D maps with semantic information are automatically generated after the exploration by the robot." This overview tells you more about the four-step method used to generate 3D models with this robot and contains several pictures of Kurt3D and its 3D laser."
Parallax would make sense. That's how most (all?) optical rangefinders work.
--matt
What's the advantage of a robot like this versus describing every object by hand, as 3d animators do (typically in some kind of interpreted language).
It seems like writing "there's a sphere of radius 3 centered here" would take less time than waiting for the robot to scan it.
well, it's like the difference between what the public perceives a dictionary as, and what a dictionary actually is.
For instance, when I was a senior in high school, Webster's started including the word ain't. Now some teachers were very upset by it while others were ecstatic.
Then my english teacher put it in perspective.
Many people belive that dictionaries define a language. They do not. They describe a language.
Same thing here. Sure you could model a building by hand, but what you get is a definition of an ideal building. Whereas 3-D laser scanning describes the building as it is, very precisely.
Real world examples where this is a good thing?
Well recently they did some 3-D scans of stonehenge. The scan data was precise enough to show markings on many stones that had never been seen before (too shallow / worn)
Or imagine a world of the future based on some form of 3d on-demand printing that's cheaper and stronger than traditional fabrication. We already have that in certain fields, BTW... it's quickly growing to be universal. You have a 3D laser system that precisely measures an existing building, and then a printer that prints new structures to be joined to the building instantly, automatically precisely sized and positioned.
I am disrespectful to dirt! Can you see that I am serious?!
The distance to objects is determined using a technique called "time of flight measurement" so yes, it's basically the time it takes for the laser to reflect.
We considered using one of these when building a mobile robot a while ago but they are quite expensive and we ended up with... Well... A robot without laser range finders.
Most laser scanners for close scanning (cm to several meters) use triangulation. Wide FOV versions can have ~1 mm precision and cover medium volumes. Narrow FOV versions can be precise to ~0.025-0.1 mm but often can only see at very close range (~10 cm to 1 m) over small volumes. One exception is the autosyncronous scanner from NRC of Canada that can measure on the order of 25 microns (~0.025 mm) over large volumes and a wide FOV, by using a narrow FOV camera that automatically follows the laser spot across a wide FOV. This also makes it "random access" which means it doesn't have to do raster scans (but can) but can trace out any shape you want.
Neptec Design Group has developed one of these for use in space. Right now, Neptec's laser scanner is being included as a required 3D scanner for analyzing the shuttle thermal protective system on orbit (tiles, RCC panels) for return-to-flight, as a result of the Columbia Accident Investigation Board report.
A good review of TOF and triangulation scanners (and structured light / fringe), including commercially available ones, is given in this paper, and here is a good list of some scanners and their type.