Navigation: Resolution of Global Costmap

Question

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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Originally posted by ROSCMBOT on ROS Answers with karma: 651 on 2014-11-07

Post score: 1

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Original comments

Comment by David Lu on 2014-11-15:
I am confused. You say your resolution is both 2.0 and 0.05. Which is it?

Comment by ROSCMBOT on 2014-11-24:
@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

Answer 1

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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Originally posted by David Lu with karma: 10932 on 2014-11-24

This answer was ACCEPTED on the original site

Post score: 3

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Original comments

Comment by ROSCMBOT on 2014-11-25:
Thanks. How can I change the actual resolution of my costmap? by changing the resolution of the png map?

Comment by David Lu on 2014-11-25:
Yes. That is correct.

Comment by ROSCMBOT on 2014-11-25:
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?

Comment by David Lu on 2014-11-25:
With the current planner, yes. Or don't use the static map.

Comment by ROSCMBOT on 2014-11-25:
What's the alternative beside static map?

Comment by David Lu on 2014-11-25:
Big empty map.

Comment by ROSCMBOT on 2014-11-25:
Thanks for the info. So the resolution of the costmaps (global and local) is always the same as that of the static map, right?

Comment by David Lu on 2014-11-25:
Yes indeed.