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Posted by John Nagle on January 20, 2008, 4:42 pm
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kartoun wrote:
> Hi,
>
> I'm looking for an accurate distance sensor (I guess that a sonar will
> be the best).
> The sensor I'm looking for should be interfaced easily with a PC
> (RS-232, USB).
Questions:
1. How big can it be?
2. What range do you need?
3. How wide a beam width do you want?
4. How much can it cost?
5. How much accuracy do you really need?
Ultrasonic units are cheap and available, but most of them
have large beam widths and have problems with reflections off
hard surfaces. Range is centimeters to 10m or so. Some
have minimum range limits.
Relative reflectance devices are cheap and available, but
usually have very limited range, a few cm. Useful for grippers
to control grasping.
Angle reflectance devices are available, not as cheap, have
ranges in the 10-20cm range or so, and are reasonably accurate.
Time-of-flight laser rangefinders have accuracy to 1cm, ranges to
tens or hundreds of meters, very narrow beam widths, and tend
to be larger and more expensive than the other options.
John Nagle
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>
> I'm looking for an accurate distance sensor (I guess that a sonar will
> be the best).