Hello everyone,

I've got some problems with the slam_gmapping. First of all, i want to use a Kinect to generate a Map from that data for my robots navigation stack. And navigate in that word/map afterwards. There will be two machines, one for the lowerlevel things like odometry measurement. And one for all the highlevel things like building an map and navigation.

Idea and Structure:

both PC are running ubuntu 16.0.4 and ROS Kinetic

1. Robots PC:

• Odometry_publisher (working)
• Motor_control (working)
• freenect driver for the Kinect publishing all the kinect data (working, very slow via wifi; 0.5 fps only)

1. Desktop PC:

• pointcloud to laserscan topic (working, very slow due to the slow pointcloud)
• slam_gmapping (proplem see below)
• a tf_broadcaster for all the needed transforming (working)
• the navigation (not working yet. need the map fist)
• Rviz to visualize the process of building the map

Things I've done so far:

Launch-files:

desktop.launch

<launch>

 <node pkg="eddie" type="tf_broadcaster" name="tf_broadcaster" output="screen">
    <param name="transform_configuration_param" value="param_value" /> 
</node> 

<node pkg="depthimage_to_laserscan" type="depthimage_to_laserscan" name="depthimage_to_laserscan">
    <param name="scan_height" value="10"/>
    <remap from="image" to="/camera/depth/image_raw"/>
</node>

<node pkg="gmapping" type="slam_gmapping" name="slam_gmapping">
    <param name="scan" value="scan"/>
    <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="0.1"/>
    <param name="srt" value="0.2"/>
    <param name="str" value="0.1"/>
    <param name="stt" value="0.2"/>            <param name="linearUpdate" value="1.0"/>
    <param name="angularUpdate" value="0.5"/>
    <param name="temporalUpdate" value="3.0"/>
    <param name="resampleThreshold" value="0.5"/>
    <param name="particles" value="30"/>
    <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>

eddie.launch

<launch>

<include file="$(find freenect_launch)/launch/freenect.launch"/>

<node pkg="eddie" type="odometry_publisher" name="odometry_publisher" output="screen">

    <param name="odom_param" value="param_value" /> 

</node> 


<node pkg="eddie" type="base_control" respawn="false" name="base_control" output="screen">

    <rosparam file="$(find navigation)/costmap_common_params.yaml" command="load" ns="global_costmap" /> 
    <rosparam file="$(find navigation)/costmap_common_params.yaml" command="load" ns="local_costmap" /> 
    <rosparam file="$(find navigation)/local_costmap_params.yaml" command="load" /> 
    <rosparam file="$(find navigation)/global_costmap_params.yaml" command="load" /> 
    <rosparam file="$(find navigation)/base_local_planner_params.yaml" command="load" /> 

</node>
</launch>

I just launch this two files individually on the machines. they work together

• i can see all topics by rostopic list
• tf-tree is perfectly working. ( transforms for: map->odom->baslink->cameralink->cameraframesxxx)

Problem:

When I start Rviz for visualisation I get the warning: "No map received" I checked following things:

• the slam_gmapping node has subscribed to tf and to the scan topic
• the scan topic is publishing ( can see it in rviz, frame is ok)
• Wifi should be not in overload ( test 13,5Mbits/sec possible; Systemonitor: 3 MiB/s)
• /map topic has no published messages

If i start all nodes on the Robot PC the map is working!

Question

Does anyone have an idea, why the map ist not published correctly when i go thrue the wifi connection? Can i reduce the mass of data sended by the freenect?

Thank you so much! Lorenz