Gmapping and CPU load [closed]

asked 2012-05-16 23:49:50 -0600

jorge gravatar image

updated 2014-01-28 17:12:21 -0600

ngrennan gravatar image

Hi all,

I'm using Gmapping to create a map with an hokuyo lx30 laser. I have created a bag file of around 20 minutes of laser scans in an indoor environment, to run Gmapping offline.

When running in the robot's Intel Atom Dual Core, it produces almost 400 scan failures, and the resulting map is really terrible.

When running in my Dual Core desktop, it produces 50 scan failures, and the resulting map is quite acceptable.

What is really surprising is that the CPU load of the Intel Atom is much lower (5% in only one of the 4 CPUs) that that of the desktop (14% in 2 of the 4 CPUs). I have tried to run rosbag play 10 times slower, and so doing both machines generate acceptable maps, dropping the failed scans to 10 and 7 in each case. Interestingly, the CPU loads remained constant in both experiments.

So it looks like Gmapping gently rejects to use the whole CPU but generates a terrible map?

Maps comparison: C:\fakepath\compare_maps.jpg

The parameters used (much more "generous" than the default ones) are:

<param name="throttle_scans" value="1" />
<param name="base_frame" value="/base_footprint" />
<param name="odom_frame" value="/odom" />
<param name="map_frame" value="/map" />
<param name="map_udpate_interval" value="2.5"/>
<param name="maxUrange" value="5.5"/>
<param name="maxRange" value="5.8"/>
<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="0.125"/>
<param name="ogain" value="3.0"/>
<param name="lskip" value="0"/>
<param name="srr" value="0.06"/>
<param name="srt" value="0.12"/>
<param name="str" value="0.08"/>
<param name="stt" value="0.12"/>
<param name="linearUpdate" value="0.3"/>
<param name="angularUpdate" value="0.15"/>
<param name="temporalUpdate" value="-1.0"/>
<param name="resampleThreshold" value="0.5"/>
<param name="particles" value="100"/>
<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="0.08"/>
<param name="llsamplerange" value="0.01"/>
<param name="llsamplestep" value="0.01"/>
<param name="lasamplerange" value="0.005"/>
<param name="lasamplestep" value="0.005"/>

But I have tried also with Gmapping default parameters and the results are comparable.

Any clues? I'm really puzzled. Btw, I use ROS electric on Ubuntu Lucid. Thanks

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Closed for the following reason question is not relevant or outdated by tfoote
close date 2014-08-16 23:53:30.213212


Note sure about the gmapping issues, but your dataset looks like you could give hector_mapping a try. With the UTM30LX we usually get good results for such indoor scenes.

Stefan Kohlbrecher gravatar image Stefan Kohlbrecher  ( 2012-05-17 01:33:22 -0600 )edit

Hey, thanks for the advice. I'll give a try. But it's 3D SLAM, isn't it? We are making 2D navigation.

jorge gravatar image jorge  ( 2012-05-22 19:29:01 -0600 )edit

By the way, I have tried same bagfile with fuerte on precise and had same results. Any feedback will be really appreciated.

jorge gravatar image jorge  ( 2012-05-22 19:29:50 -0600 )edit

No, hector_mapping also provides 2D grid maps, so it should directly work.

Stefan Kohlbrecher gravatar image Stefan Kohlbrecher  ( 2012-05-24 06:46:07 -0600 )edit

I'm experiencing some dependencies problems compiling hector_slam. It cannot find eigen package. It's already updated to work on fuerte?

jorge gravatar image jorge  ( 2012-05-28 15:18:17 -0600 )edit

Is it practical to post the bagfiles?

Mac gravatar image Mac  ( 2012-07-01 18:29:18 -0600 )edit