laser assembler ignore ignore_laser_skew not working [closed]

asked 2013-04-01 02:04:27 -0600

Sentinal_Bias gravatar image

updated 2014-01-28 17:15:59 -0600

ngrennan gravatar image

Hi

I am tilting a hokuyo laser, however i believe the laser skew is interfering with the obstacle detection technique.

I enable the parameter ignore_laser_skew = false in my launch file. is there any way to check if the laser assembler is actually removing the laser skew?

Basically i think i have to publish my laser tilt frame at a faster rate.

here is my launch file

<launch>
<node pkg="laser_filters" type="scan_to_scan_filter_chain" output="screen" name="laser_filter">
      <remap from="scan" to="/iri_hokuyo_laser/scan" />
      <rosparam command="load" file="$(find laser_filters)/examples/median_filter_5_example.yaml" />
</node>
<node type="laser_scan_assembler" pkg="laser_assembler"
        name="my_assembler">
    <remap from="scan" to="scan_filtered" />
    <param name="max_scans" type="int" value="1" />
    <param name="fixed_frame" type="string" value="global"/>
    <param name="ignore_laser_skews" type="bool" value="False"/>
</node>
</launch>

I get the feeling the laser filters are creating a slight time delay such that the ignore laser skew functionality of the laser assembler is not working properly

also my node sometimes crashes with an exit code of -6

It looks like its making the skew worse

for example when the laser is scanning forward a bucket is rendered higher relative to the global coordinate system when the bucket is rendered with the laser scanning backwards.

I think this is error due to the LIDAR scan being skewed due to the rotation but the ignore_skew = false setting seems to be doing nothing because the effect is the same with and without it.

my tilt unit is scanning from a fixed position and the LIDAR tilt frame is being published at 500hz which should be more than enough to reduce the lidar skew error. The lidar is being tilted at 30-40 degrees per second

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Closed for the following reason question is not relevant or outdated by tfoote
close date 2015-11-19 20:02:10.356124