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frontier_exploration with turtlebot

asked 2014-10-29 04:35:52 -0600

charkoteow gravatar image

updated 2014-10-30 06:57:57 -0600

I'm trying to get the frontier_exploration package to work with my TurtleBot. But so far it's not working.

The launch file

  <node pkg="gmapping" type="slam_gmapping" name="slam_gmapping" output="screen">
    <remap from="scan" to="/scan2" />
      occ_thresh: 0.25
      odom_frame: odom
      map_update_interval: 5.0
      maxUrange: 6.0
      maxRange: 8.0
      sigma: 0.05
      kernelSize: 1
      lstep: 0.05
      astep: 0.05
      iterations: 5
      lsigma: 0.075
      ogain: 1.0
      lskip: 0
      srr: 0.01
      srt: 0.02
      str: 0.01
      stt: 0.02
      linearUpdate: 0.5
      angularUpdate: 0.436
      temporalUpdate: -1.0
      resampleThreshold: 0.5
      particles: 80
      xmin: -1.0
      ymin: -1.0
      xmax: 1.0
      ymax: 1.0
      delta: 0.05
      llsamplerange: 0.01
      llsamplestep: 0.01
      lasamplerange: 0.005
      lasamplestep: 0.005
      base_frame: base_link
  <node name="rviz" pkg="rviz" type="rviz">

          <include file="$(find turtlebot_navigation)/launch/includes/velocity_smoother.launch.xml"/>
          <include file="$(find turtlebot_navigation)/launch/includes/safety_controller.launch.xml"/>

          <arg name="odom_topic" default="odom" />

   <node pkg="move_base" type="move_base" respawn="false" name="move_base" output="screen">
          <rosparam file="$(find turtlebot_navigation)/param/costmap_common_params.yaml" command="load" ns="global_costmap" />
          <rosparam file="$(find turtlebot_navigation)/param/costmap_common_params.yaml" command="load" ns="local_costmap" />
          <rosparam file="$(find turtlebot_navigation)/param/local_costmap_params.yaml" command="load" />
          <rosparam file="$(find turtlebot_navigation)/param/global_costmap_params.yaml" command="load" />
          <rosparam file="$(find turtlebot_navigation)/param/base_local_planner_params.yaml" command="load" />
          <rosparam file="$(find turtlebot_navigation)/param/move_base_params.yaml" command="load" />
          <remap from="cmd_vel" to="navigation_velocity_smoother/raw_cmd_vel"/>
          <remap from="odom" to="$(arg odom_topic)"/>


   global_frame: /map
   robot_base_frame: /base_footprint
   update_frequency: 3.0
   publish_frequency: 0.0
   static_map: true
   transform_tolerance: 0.5


   global_frame: /odom
   robot_base_frame: /base_footprint
   update_frequency: 5.0
   publish_frequency: 2.0
   static_map: false
   rolling_window: true
   width: 4.0
   height: 4.0
   resolution: 0.05
   transform_tolerance: 0.5

Errors from the frontier_exploration terminal

[ WARN] [1414574875.215553173]: Please select an initial point for exploration inside the polygon
[ INFO] [1414574876.981956729]: Sending goal
[ INFO] [1414574877.352866124]: Using plugin "static"
[ INFO] [1414574877.621707478]: Requesting the map...
[ INFO] [1414574877.775594588]: Resizing costmap to 576 X 288 at 0.050000 m/pix
[ INFO] [1414574877.847249155]: Received a 576 X 288 map at 0.050000 m/pix
[ INFO] [1414574877.847298258]: Subscribing to updates
[ INFO] [1414574878.016550480]: Using plugin "explore_boundary"
[ INFO] [1414574878.541237670]: Using plugin "sensor"
[ INFO] [1414574878.664303536]:     Subscribed to Topics: /scan2
[ INFO] [1414574879.327905514]: Using plugin "inflation"
[ERROR] [1414574880.852823897]: Exception thrown while processing service call: Lookup would require extrapolation into the past.  Requested time 1414574873.590463123 but the earliest data is at time 1414574878.157772422, when looking up transform from frame [odom] to frame [map]
[ERROR] [1414574880.853237138]: Service call failed: service [/explore_server/explore_costmap/explore_boundary/update_boundary_polygon] responded with an error: Lookup would require extrapolation into the past.  Requested time 1414574873.590463123 but the earliest data is at time 1414574878.157772422, when looking up transform from frame [odom] to frame [map]
[ERROR] [1414574880.853397382]: Failed to set region boundary

Errors from my gmapping launch file terminal

[ WARN] [1414574406.526808975]: Could not transform the global plan to the frame of the controller ...
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have you finally got it to work? its driving me nuts lol any luck, progress, idea? here is my Question I'd appreciate any little help. thanks

sobot gravatar image sobot  ( 2015-05-05 14:37:20 -0600 )edit

i really can't pin down the exact problem. sometimes it works, sometimes it doesn't. even with the clock synced properly and i also set the openni publish transform to false to fix the kinect's tf issues. we've moved on from mapping to olfaction recently so I can't help you much for the time being.

charkoteow gravatar image charkoteow  ( 2015-05-06 01:09:27 -0600 )edit

thank you for the response. one last thing, i thought i would borrow the configs that you posted here, to test on my bot. apart from clock n stuff, you did use the same config as posted here right?

sobot gravatar image sobot  ( 2015-05-06 03:57:03 -0600 )edit

Almost all of it are the same. I've increased the transform tolerance, update_frequency, publish_frequency and changed robot_base_frame to base_link on the global costmap params and frontier's launch file. I think they must be the same. Check your launch file....

charkoteow gravatar image charkoteow  ( 2015-05-06 04:32:47 -0600 )edit

...the one i've uploaded was mainly about gmapping & move_base. i think i should update my Q.

charkoteow gravatar image charkoteow  ( 2015-05-06 04:33:35 -0600 )edit

Thanks a bunch for the replies. im so stuck on finding a working exploration package you have no idea lol. have a good day!

sobot gravatar image sobot  ( 2015-05-06 04:47:20 -0600 )edit

Maybe either of you can help me at

130s gravatar image 130s  ( 2016-06-15 00:05:35 -0600 )edit

1 Answer

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answered 2014-10-29 22:49:24 -0600

paulbovbel gravatar image

updated 2014-10-29 22:58:51 -0600

Due to the time difference in the timestamps (3-5 seconds), it looks like you have tf setup problems, or some serious latency issues.

You can set a tolerance value on amcl to future date the tf timestamps and prevent extrapolation errors, but the most you'd ever need would be ~0.1 s or so.

Are you running the nodes on separate computers? Are the clocks synced with chrony or something similar?

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I am using two computers. One laptop on the bot and a pc as workstation. Ran all the essentials like turtlebot startup and kinect's packages on the laptop. All other nodes are on the pc.

I do get some tf error sometimes. All of it were kinect's tf. It flickers on RViz.

Updated the Q with tf frames

charkoteow gravatar image charkoteow  ( 2014-10-30 06:59:32 -0600 )edit

Try going through this

paulbovbel gravatar image paulbovbel  ( 2014-10-30 08:40:23 -0600 )edit
[ WARN] [1417145722.105144612]: Could not get robot pose, cancelling reconfiguration
charkoteow gravatar image charkoteow  ( 2014-11-27 21:39:33 -0600 )edit

That is also a TF issue, likely cause by your multi-machine setup. Please open a separate question if you need more info about setting up your network properly. Main issues would be latency, and time synchronization.

paulbovbel gravatar image paulbovbel  ( 2014-11-28 10:08:57 -0600 )edit

Hi, I am having the exact same problem as described in this post but I'm not running on multiple workstations. I am running everything on one computer and i'm running the nodes separately by their own launch file (i.e. gmapping, move_base, TF from odom->base_link->laser, and exploration).

RND gravatar image RND  ( 2015-03-10 04:41:36 -0600 )edit

Also, I'm using gmapping to provide the map->odom transform and of course to build the map.

RND gravatar image RND  ( 2015-03-10 05:02:28 -0600 )edit

I doubt it's the exact same problem, since @charkoteow's issue was extremely post-dated timestamps. Either way, please open a new question, and provide some more information.

paulbovbel gravatar image paulbovbel  ( 2015-03-10 08:31:34 -0600 )edit

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Asked: 2014-10-29 04:35:52 -0600

Seen: 1,643 times

Last updated: Oct 30 '14