[ros-users] AMCL, Map Server, Stage World file

[Suraj Swami]

Hi Brain,

I am still not able to get amcl working. I changed the resolution in stage
world file and in the map.yamp file .


# load an environment bitmap
floorplan
(
  name "willow"
  bitmap "cave.pgm"
  size3 [22.36067 22.36067 0.5]  # Its at 500 * 500 pixel image.
  pose [0 0 0]
)

image: cave.pgm
resolution: 0.002
origin: [0.0, 0.0, 0.0]
occupied_thresh: 0.65
free_thresh: 0.196
negate: 0

I do not get right location. Do I need to take care of anything else.

Thanks for the help.

-Suraj.


> hi Suraj,
>
> You probably have the resolution set incorrectly, but understandably
> so, in map.yaml.  In the stage .world file, 'resolution' determines
> the resolution of the underlying grid that's used for simulation.  The
> resolution of a bitmap that you load (for example, to be used as a
> background map), is determined by the combination of the bitmap's size
> in pixels, and the size that you specify for the bitmap.
>
> In this case, you're using cave.pgm, which I assume was created from
> Stage's cave.png, which is 500x500 pixels.  Given the size you're
> setting, 54.0x58.7, the map resolution is about 0.11 m/pixel.  That's
> the value you want to put in map.yaml.
>
> Now, why would a square bitmap be given a different size in X and Y?
> Depending on the version of Stage you're using, the map boundaries
> might be determined by the farthest-out black pixels, as opposed to
> the actual image boundaries.  The slightly different values you're
> using might be an attempt to account for the non-square scaling that
> can result.  There's a ticket for that:
> https://code.ros.org/trac/ros-pkg/ticket/4133 .
>
>        brian.
>
> On Thu, Jun 10, 2010 at 11:42 PM, Suraj Swami <suraj.g.swami at gmail.com>
> wrote:
> > Hi,
> > I am trying to get understand how to use the AMCL package. I am using
> > simulator stage. And have written a ?small node to make the robot move in
> > the map. But I am not getting right amcl_pose values.
> > I am not sure if my map_server and stage are well synchronized to have
> the
> > map data, resolution and origin.
> > FILE: map.yaml
> > image: cave.pgm
> > resolution: 0.02
> > origin: [0.0, 0.0, 0.0]
> > occupied_thresh: 0.65
> > free_thresh: 0.196
> > negate: 0
> >
> > FILE: MCL.world
> > define block model
> > (
> > ??size3 [0.5 0.5 0.5]
> > ??gui_nose 0
> > )
> > define topurg laser
> > (
> > ??range_min 0.0
> > ??range_max 30.0
> > ??fov 360
> > ??samples 720
> > ??# generic model properties
> > ??color "black"
> > ??size [ 0.05 0.05 0.1 ]
> > )
> > define erratic position
> > (
> > ??#size3 [0.415 0.392 0.25]
> > ??size3 [0.35 0.35 0.25]
> > ??origin3 [-0.05 0 0 0]
> > ??gui_nose 1
> > ??drive "diff"
> > ??topurg(pose [0.050 0.000 0.000])
> > )
> > define floorplan model
> > (
> > ??# sombre, sensible, artistic
> > ??color "gray30"
> > ??# most maps will need a bounding box
> > ??boundary 0
> > ??gui_nose 0
> > ??gui_grid 0
> > ??gui_movemask 0
> > ??gui_outline 0
> > ??gripper_return 0
> > ??fiducial_return 0
> > ??laser_return 1
> > )
> > # set the resolution of the underlying raytrace model in meters
> > resolution 0.02
> > interval_sim 1 ?# simulation timestep in milliseconds
> > interval_real 1 ?# real-time interval between simulation updates in
> > milliseconds
> > window
> > (
> > ??size [ 675.0 745.0 ]
> > ??center [678.990 293.960]
> > ??rotate [ 0.000 0 ]
> > ??scale 28.806
> > )
> > # load an environment bitmap
> > floorplan
> > (
> > ??name "willow"
> > ??bitmap "cave.pgm"
> > ??size3 [54.0 58.7 0.5]
> > ??pose [0 0 0]
> > )
> >
> >
> > # throw in a robot
> > erratic( pose [0 0 0.000] name "era" color "blue")
> > block( pose [-13.924 25.020 0.000] color "red")
> >
> >
> > Is there a problem to synchronize the two files or is there any other
> > parameters that I need to take care of ?
> > Thank you.
> > Regards,
> > Suraj Swami
> >
> >
> >
> >
> > _______________________________________________
> > ros-users mailing list
> > ros-users at code.ros.org
> > https://code.ros.org/mailman/listinfo/ros-users
> >
> >
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osuosl.org/pipermail/ros-users/attachments/20100621/b56f76d7/attachment-0002.html>