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Navigation: Resolution of Global Costmap

asked 2014-11-07 21:24:58 -0500

ROSCMBOT gravatar image

updated 2014-11-14 21:25:05 -0500

Hi,

When I set the resolution parameter in global_costmap_params.yaml to different values (for instance 2.0) in my navigation package, I expect to get waypoints from the global planner on /move_base/NavfnROS/plan that are 2m apart, but this does not seem to be happening. My map resolution is 0.05, and the resolution parameter in local_costmap_params.yaml is also set to 0.05.

Here are some sequential sample points I get from the global planner:

    x: 0.730995153353
    y: -4.30375223612
    z: 0.0

    x: 0.740522741385
    y: -4.32686625014
    z: 0.0

    x: 0.750001501292
    y: -4.3499985747
    z: 0.0

    x: 0.800001502037
    y: -4.39999857545
    z: 0.0

    x: 0.81506729126
    y: -4.3626947403
    z: 0.0
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Comments

I am confused. You say your resolution is both 2.0 and 0.05. Which is it?

David Lu gravatar image David Lu  ( 2014-11-15 14:30:44 -0500 )edit

@David Lu, Initially the resolution parameter in map.yaml, global_costmap_params.yaml, and local_costmap_params.yaml was set to 0.05 . Since I intended to increase the distance between the waypoints generated by global planner, I only changed the resolution in global_costmap_params.yaml to 2

ROSCMBOT gravatar image ROSCMBOT  ( 2014-11-24 21:17:19 -0500 )edit

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answered 2014-11-24 22:53:19 -0500

David Lu gravatar image

In this example, you have not changed the actual resolution of your costmap. The parameter files are overridden to match whatever the global map has as a resolution.

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Comments

Thanks. How can I change the actual resolution of my costmap? by changing the resolution of the png map?

ROSCMBOT gravatar image ROSCMBOT  ( 2014-11-24 23:07:45 -0500 )edit

Yes. That is correct.

David Lu gravatar image David Lu  ( 2014-11-25 00:19:10 -0500 )edit

So If I want to get the Global Planner to generate waypoints with a distance of 2.0m from each other, then the only way is to have a png map at 2.0 m/pix as input?

ROSCMBOT gravatar image ROSCMBOT  ( 2014-11-25 00:40:57 -0500 )edit

With the current planner, yes. Or don't use the static map.

David Lu gravatar image David Lu  ( 2014-11-25 09:53:14 -0500 )edit

What's the alternative beside static map?

ROSCMBOT gravatar image ROSCMBOT  ( 2014-11-25 10:16:24 -0500 )edit

Big empty map.

David Lu gravatar image David Lu  ( 2014-11-25 10:41:34 -0500 )edit

Thanks for the info. So the resolution of the costmaps (global and local) is always the same as that of the static map, right?

ROSCMBOT gravatar image ROSCMBOT  ( 2014-11-25 10:55:45 -0500 )edit

Yes indeed.

David Lu gravatar image David Lu  ( 2014-11-25 11:52:30 -0500 )edit

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Asked: 2014-11-07 21:24:58 -0500

Seen: 2,501 times

Last updated: Nov 24 '14