[ros-users] exception in transform listener

[Michal.Stolba at cis.strath.ac.uk]

Hi,

thanks for the reply. Gmapping is configured with <param name="odom_frame"
value="odom_combined"/>

i'm launching this configuration:

<launch>
  <include file="$(find pr2_machine)/$(env ROBOT).machine" />
  <include file="$(find hi_level_navigation)/launch/slam_gmapping.xml" />
  <include file="$(find pr2_navigation_teleop)/teleop.xml" />
  <include file="$(find pr2_navigation_perception)/lasers_and_filters.xml" />
  <include file="$(find pr2_navigation_perception)/ground_plane.xml" />
  <include file="$(find pr2_navigation_slam)/move_base.xml" />
</launch>

where slam_gmapping.xml is:

<launch>
    <node pkg="gmapping" type="slam_gmapping" name="slam_gmapping"
output="screen">
      <remap from="scan" to="base_scan"/>
      <param name="odom_frame" value="odom_combined"/>
      <param name="map_update_interval" value="5.0"/>
      <param name="maxUrange" value="16.0"/>
      <param name="sigma" value="0.05"/>
      <param name="kernelSize" value="1"/>
      <param name="lstep" value="0.05"/>
      <param name="astep" value="0.05"/>
      <param name="iterations" value="5"/>
      <param name="lsigma" value="0.075"/>
      <param name="ogain" value="3.0"/>
      <param name="lskip" value="0"/>
      <param name="srr" value="0.01"/>
      <param name="srt" value="0.02"/>
      <param name="str" value="0.01"/>
      <param name="stt" value="0.02"/>
      <param name="linearUpdate" value="1.0"/>
      <param name="angularUpdate" value="0.436"/>
      <param name="temporalUpdate" value="5.0"/>
      <param name="resampleThreshold" value="0.5"/>
      <param name="particles" value="80"/>
      <param name="xmin" value="-50.0"/>
      <param name="ymin" value="-50.0"/>
      <param name="xmax" value="50.0"/>
      <param name="ymax" value="50.0"/>
      <param name="delta" value="0.05"/>
      <param name="llsamplerange" value="0.01"/>
      <param name="llsamplestep" value="0.01"/>
      <param name="lasamplerange" value="0.005"/>
      <param name="lasamplestep" value="0.005"/>
    </node>
</launch>

sometimes (quite rarely) the transform is received correctly.

Thanks very much,

Michal

> Perhaps gmapping is configured with odom_frame == base_footprint?
>
> 	brian.
>
> On Fri, Jun 25, 2010 at 10:32 AM, Wim Meeussen
> <meeussen at willowgarage.com> wrote:
>> Michal,
>>
>>> RESULTS: for /map to /base_footprint
>>> Chain is: /map -> /base_footprint -> /odom_combined
>>> Net delay     avg = 0.020768: max = 0.064
>>
>> [...]
>>
>>> the only weird thing is, that in rviz the transform arrows shows like
>>> this: /base_footprint -> /odom_combined -> /map
>>> might this be a sign of some problem?
>>
>> Yes, This is most likely your problem. It appears that you have a tf
>> publisher from map to base_footprint, and another publisher from
>> odom_combined to base_footprint. So the base_footprint frame has two
>> parents.  In our setup we have amcl publish the transform from map to
>> odom combined, and the robot pose ekf publish the transform from
>> odom_combined to base_footprint.  What setup are you running? Did you
>> reconfigure amcl to publish a different tf transform?
>>
>> Wim
>>
>>
>>
>>
>>
>> --
>> Wim Meeussen
>> Willow Garage Inc.
>> <http://www.willowgarage.com)
>> _______________________________________________
>> ros-users mailing list
>> ros-users at code.ros.org
>> https://code.ros.org/mailman/listinfo/ros-users
>>
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