precise range finder

[benji]

hey guys, i was working on a project that should indicate ranges in terms of 1/10 milli-meters, so anybody knows such a range finder that can provide such great accuracy? the maximum range isnt necessary ,it can be 20 cm as a maximum

[krich]

I've been looking into rangefinders quite a bit these days.  Although my experience is largely theoretical, nothing that I've been looking at is that accurate.  I haven't been looking into Laser Rangefinders because of the cost.  That's the only thing I can think of that even has a chance of giving you the 1/10mm resolution.

On another note, those sensors in Optical Mice (Avago/Agilent ADNS-2051, for example), have a resolution of 400-1600 CPI.  That meets your requirement, but its not necessarily a "range finder", more like an encoder wheel substitute.  It would be able to measure the distance from point A to point B very very accurately.  The downside is that your robot would have to move from point A to point B to measure it.

Ken.

[benji]

i cant get my bot to move there, no, that wont do

[JonHylands]

As far as I know, the only way you could do that would be to have a physical connection between the robot and the object being sensed, and use a very accurate linear sensor.

- Jon

[benji]

can lasers provide such precision?

[frank26080115]

jackscrew + stepper motor + contact sensor

use your imagination

[benji]

i just dnt want to contact anything

[Dank55]

I posted this before, but the search engine isn't pulling it up, so here it is again:

"Phase-shift laser rangefinders" measure distance along a line of sight, and this gives them much better range and accuracy than ultrasonic or infrared rangefinders and proximity detectors. You can find lots of them for less than $100 on Amazon, but I'll just mention the specs on one as an example of what you can get for around $130: the Bosch DLE50. It's tiny (175g or 6 ounces, including batteries), has a range of 5cm to 50m (2 inches to 55 yards), and is accurate to within 1.5mm (0.06 inches) at a range of 30m or less. Lasers are notorious battery drainers, but that's not a killer: you can use other sensors until you need the greater accuracy and range. An annoying caveat is, I haven't yet found a cheap one with a data port, and the only one I've found with Bluetooth is over $600. But I expect this flaw will be remedied soon.

Dan
#wikiversity on irc.freenode.net

[benji]

is accurate to within 1.5mm

i need way more accuracy

anyways thank you guys for answering

[Admin]

benji . . . you are asking for insane precision . . .

I posted this before, but the search engine isn't pulling it up

Yea the search engine is horrible. The advanced search feature helps a bit. And sometimes I have luck using the google search on the forum:
http://www.societyofrobots.com/robot_tutorial_index.shtml

[benji]

benji . . . you are asking for insane precision . . .

its that i once saw a tv program adn they talked about some folks who did a 3d scanner for shapes
,its like a small fridge where you put somthing like a cup and you close the door
this thing scans the shap and draw it on the computer,, its a really amazing device
and the precision is very high, so i was guessing what presice sensors this thing is using ,thats all