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gmapping resolution

asked 2013-06-27 02:31:09 -0500

acp gravatar image

updated 2013-06-27 02:49:15 -0500

I have a basic question.

Rviz shows a resolution of the map of 0.05.

If I have a (x,y) coordinate of [29, 1983], what is the value in meters of the previous coordinate. I mean [x meters, y meters]

My best guess is that every cell has a value of 0.05, but im not sure

In advance, thank you for your help :)

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answered 2013-06-27 02:47:18 -0500

Lucile gravatar image

I think those coordinates are meters yet.

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well, it think, it can not be, because I have measured the place and has max of 40-45 meters, and 1983*0.05 ans = 99.150

acp gravatar imageacp ( 2013-06-27 02:55:37 -0500 )edit

What coordinates are you talking about exactly ?

Lucile gravatar imageLucile ( 2013-06-27 03:03:31 -0500 )edit

But, I may think that every 50 cells is a meter

acp gravatar imageacp ( 2013-06-27 03:45:57 -0500 )edit

How could that be ? What coordinates are you talking about exactly ? Where did you find them ?

Lucile gravatar imageLucile ( 2013-06-27 03:55:07 -0500 )edit

The coordinates I have mentioned are the coordinates of the empty area of the global map, they have been taken from the /map topic under gmapping packege. The other issue here is how to relate the initial position of the robot with the origin of the local map.

acp gravatar imageacp ( 2013-06-27 04:04:17 -0500 )edit

I have seen the documentation, and they are 20 cells per meter so it gives a resolution of 0.05. I may have something wrong in the way I get the coordinates from the /map topic under gmapping packege

acp gravatar imageacp ( 2013-06-27 04:20:29 -0500 )edit

Well, if you look at here : ros.org/doc/api/nav_msgs/html/msg/MapMetaData.html they say that data from /map topics are given in meters and radians. And they also say in REP 105 that mobile platform's position is relative to the map's frame

Lucile gravatar imageLucile ( 2013-06-27 04:28:45 -0500 )edit

Thnax for the answer, my issue is how to interpret it. I have measured the width of the map, 40-45 m, and I get map.info.width=1984, this means that 1984*0.05= 99.250m, something might be wrong.

acp gravatar imageacp ( 2013-06-27 21:42:50 -0500 )edit

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Asked: 2013-06-27 02:31:09 -0500

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Last updated: Jun 27 '13