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Gmapping stops updating map

asked 2014-06-23 07:19:55 -0500

julled gravatar image

updated 2014-06-24 15:02:16 -0500

Hey,

after finally getting deeper into ROS and understanding most of the things which are necessary for using the Gmapping-SLAM ( basics like tf, odom etc ) im now at the point of testing the whole thing. There is the Problem that Gmapping stops updating the map after serval scans. But first of all i want to give you a short overview:

What i want to do: Im trying to use a simulated 2D-Scanner in VREP as source for Gmapping.

Systemconfig: I use Groovy on a Ubuntu 12.04 LTS on a old IBM X41 Laptop (1.5Ghz Centrino SinglecoreCPU)

Progress:

  1. I transfered the /scan and /odom-Topic from VREP to ROS.
  2. I wrote some code (odom_baselink_tf.py) for tf of /base_link to /odom:
def metadata_odom(data):
    global p, q, info
    info = data
    p = data.pose.pose.position
    q = data.pose.pose.orientation
    rospy.loginfo(Received odom)
...
broadcaster.sendTransform(
  (p.x, p.y, 0), 
  (q.x, q.y, q.z, q.w),
  rosnow,
  base_lin,
  odom
  )

3 . I use a static tf transform between base_link and LaserScanner_Frame: rosrun tf static_transform_publisher 0 0 0 0 0 0 base_link LaserScanner_Frame 100

This results in the following tf-tree: image description

I use Gmapping with the following Settings:

    <param name="map_update_interval" value="2"/>  <!--2-->
    <param name="maxUrange" value="5.5"/> 
    <param name="sigma" value="0.05"/>
    <param name="kernelSize" value="1.0"/>
    <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"/><!--1.0-->
    <param name="str" value="0.01"/>
    <param name="stt" value="0.02"/>
    <param name="linearUpdate" value="0.1"/>     
    <param name="angularUpdate" value="0.1"/>  
    <param name="temporalUpdate" value="-1.0"/> 
    <param name="resampleThreshold" value="0.5"/>
    <param name="particles" value="50"/>  <!--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="0.03"/>
    <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 if i use these settings, there is the problem that Gmapping stops updating the map after serval scans. If i look at the SLAM-Debug-Messages there are serval odd messages:

update frame 7
update ld=0.0495583 ad=0.179583
Laser Pose= 13.7771 3.96148 -0.695156
m_count 7
[DEBUG] [1403512083.321312113]: TF operating on not fully resolved frame id base_link, resolving using local prefix 
[DEBUG] [1403512083.321624443]: TF operating on not fully resolved frame id odom, resolving using local prefix 
Average Scan Matching Score=164.656
neff= 49.8545
Registering Scans:Done
[DEBUG] [1403512083.931338640]: scan processed
[DEBUG] [1403512083.933940439]: new best pose: 13.752 3.943 -0.644
[DEBUG] [1403512083.935263651]: odom pose: 13.777 3.961 -0.695
[DEBUG] [1403512083.936265942]: correction: -0.025 -0.018 0.051
[DEBUG] [1403512083 ...
(more)
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Are you maybe mixing times from different sources? Is there a /clock topic or/and maybe a simulation time?

dornhege gravatar imagedornhege ( 2014-06-25 06:03:26 -0500 )edit

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answered 2014-06-23 09:05:47 -0500

dornhege gravatar image

The fully resolved frame id warnings are not problematic. It's basically base_link vs. /base_link, where if you just send base_link it's gonna make it to be /base_link. This is usually what you want.

What you should look at is the "Out of the back of Cache Time(stamp: 1403512072.685 + cache_length: 10.000 " and " Time jumped forward by [5.379792] for timer of period ". This seems like something is wrong with the messages you are sending. All messages should be arriving continuously with a nicely increasing timestamp and laser and tf should fit together. It seems that something in your data doesn't.

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Hey domhege, thank you for your answer! You can see a new EDIT at the question. gruß aus Berlin

julled gravatar imagejulled ( 2014-06-24 13:13:24 -0500 )edit

Hi julled, sorry for the off-topic but i think we try to do pretty much the same system. Could you send me a mail to andreas.gerken (at) thi.de so we can join powers? Thanks Andreas Gruß aus Ingolstadt :)

andreas.gerken gravatar imageandreas.gerken ( 2014-06-25 11:54:32 -0500 )edit

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Asked: 2014-06-23 07:19:55 -0500

Seen: 920 times

Last updated: Jun 24 '14