Re: [oopic] New range finder needed

Much, I can visualize that pretty well. It sounds like the ideal imager would
be the CMUCam, or something like that, since you would want some kind of 2D
array like a camera. Obviously, that would have to be wi-fi or some such,
since the datastream would be pretty hefty. It also sounds like if I was to
go that route, I might as well do some image manipulation, as well.

Also sounds like it might cost a bit, so it will have to wait, as spring is
upon me, and all my cash will go into my back yard for the next few months,
but at least I can start researching the hardware a bit.

Thanks for the tips to all of you.

Brian Lloyd-6 wrote:
>
> Let me see if I can describe the optical rangefinder using a scanning
> LASER a bit better.
>
> The rangefinder is optical and works by geometry. It requires a 2D
> imager that is capable of "seeing" the reflected light from the LASER
> in very high contrast or the imager must be able to discern the color
> of the LASER from all other colors.
>
> The imager looks forward with the focal plane vertical (normal to the
> floor). The scanning laser is mounted well above (or below) the imager
> and projects a plane of light that makes an acute angle to the normal
> line through the center of the imager.
>
> Imagine a wall that is (relatively) far away. Also imagine that you
> are looking at the whole lash-up from the side. You will see that the
> scanned plane intersects the wall near the floor. After passing
> through the lens of the imager it will appear near the top of the
> focal plane.
>
> Now imagine the wall moving closer to the sensor system. The scanned
> plane now appears higher on the wall and its image is lower on the
> focal plane of the sensor.
>
> So if we examine the focal plane of the imager, variations in the
> position of the scanned line on the Y axis denote distance and
> variations on the X-axis denote left/right angular displacement.
>
> I believe that the CMUcam has a mode for tracking certain colors. If
> calibrated to track the color of the LASER, it can give back the
> coordinates of the scan line. From that you can determine direction
> and distance to multiple objects very quickly.
>
> Is this any clearer?
>
> --
>
> Brian Lloyd Granite Bay Montessori
> brian AT gbmontessori DOT com 9330 Sierra College Blvd.
> +1.916.367.2131 (voice) Roseville, CA 95661, USA
>

http://www.gbmontessori.com
>
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> — Antoine de Saint-Exupéry
>
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> Yahoo! Groups Links
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>

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