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Parallax Laser Range Finder — Parallax Forums

Parallax Laser Range Finder

mark.jmark.j Posts: 7
edited 2012-07-01 07:36 in Accessories
I need a sensor that can give me fairly accurate distance readings for points of interest on the ground from a robot. This will be outdoors, where the sun shines brightly, and may be used on lightly colored sand. Given this information, does anyone know if the Parallax laser range finder would be able to give accurate readings? I know it has calibration for lighting conditions, but I'm concerned that bright sunlight might make the laser dot too hard for the camera to see against the sand. Thanks.

link to the LRF: http://www.parallax.com/Store/Sensors/ObjectDetection/tabid/176/ProductID/774/List/0/Default.aspx?SortField=ProductName,ProductName

Comments

  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-06-29 21:12
    Mark,

    What kind of distances are you after?

    I have one of these LRF but I haven't tried it outside myself. It's late PM here in Idaho now but I'll try out the LRF in the sunlight tomorrow if you'd like. I might not be able to find any light colored sand but I could try it out on some other light colored targets.
  • mark.jmark.j Posts: 7
    edited 2012-06-29 22:06
    Duane,

    Thanks for offering to try it outside, that would be great!

    I'm thinking the distances for my application will range from a minimum of about 20 cm to a maximum of 115 cm with a most typical value of around 40 cm.
  • Duane DegnDuane Degn Posts: 10,588
    edited 2012-07-01 07:36
    Mark,

    I tried using the sensor outside yesterday. I didn't have any light colored sand to test it on but I used some light concrete to test it.

    It had a hard time finding the range of the concrete in direct sunlight particularly at longer distances (> 70m). As soon as I pointed the laser at a shadow area, it would quickly find the distance but the sensor only occasionally returned a distance from the target in direct sunlight.

    I think targets 40cm away were readable in direct sunlight a good portion of the time.

    I think a higher power laser would be easier for the sensor to see. Deal extreme sells all sorts of lasers. You should probably be able to increase the range by using one of their higher power lasers. You'd need to have the high power laser triggered by the LRF since it takes a picture both with the laser light and without the laser on to make sure it's really seeing the laser and not just a bright spot.
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