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gmapping missing spots

asked 2013-05-22 11:43:12 -0500

mortonjt gravatar image

updated 2013-05-23 02:41:01 -0500

Hello,

For our robot, slam gmapping have been configured. However, when we display our cost maps in rviz, we see a big gapping hole that isn't being mapped

screenshot

I know that there are quite a few parameters that can be set for gmapping.

Are any of these parameters responsible for this hole in our mapping?

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answered 2013-05-23 05:25:42 -0500

marcusrm gravatar image

For the SICK LMS lidar you can set the "use_rep_117_" global parameter to "false" to force it to report readings in legacy format instead of using Inf/NaN. It seems that the gmapping package rejects Inf/NaN values.

Use this information in combination with the maxRange and maxUrange suggestion that Ben has offered.

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answered 2013-05-22 11:51:51 -0500

Ben_S gravatar image

What is the maximum range of your laser scanner and what is the reading it gives if there is no object in range of the beam?

I think the problem is, that space where no echo is received by the scanner, is not marked as free. Have a look at the documentation of the ~maxRange parameter and try the proposed setting maxUrange < maximum range of the real sensor <= maxRange. But as far as i know, this depends on the scanner reporting readings of max range and not zero or NaN for beams where no echo is received.

If this does not solve your problem, maybe you could post a small bag file, so we can have a look for our own. :)

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answered 2013-05-23 06:39:53 -0500

updated 2013-05-23 20:16:38 -0500

Note that marking areas with no measurements received to be free can be risky in some cases, as you effectively don't know if things are out of range, or there's something in front of your LIDAR that the sensor just can't see (and that being the reason for getting no returns). The latter is a real possibility for some combinations of LIDARs and surface materials in the environment.

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answered 2015-03-19 15:00:56 -0500

Same problem here as receiving NAN if we get rid of the NAN how we make sure we're receiving the right data?

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Asked: 2013-05-22 11:43:12 -0500

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Last updated: May 23 '13