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Remote Mapping

Robot

For simplification, I will just show nodes/launch files used for mapping. Your robot may have other stuff launched at the same time. Here I assume that the ROS Master is on the robot, and a Kinect is used.

1. [Optional]: To avoid host name resolution issues, set ROS_IP environment variable for the robot:

• $ ifconfig
  eth0      Link encap:Ethernet  HWaddr ##:##:##:##:##:##  
            inet addr:192.168.1.3  Bcast:192.168.1.255  Mask:255.255.255.0
  ...
  $ export ROS_IP=192.168.1.3

2. We will throttle the Kinect messages on the robot at 5 Hz to reduce the bandwidth used on the network (reducing latency). We can use rtabmap_ros/data_throttle nodelet for convenience. Create a file called freenect_throttle.launch and copy/paste this code:

• <launch>
    <include file="$(find freenect_launch)/launch/freenect.launch">
       <arg name="depth_registration" value="True" />
    </include>
  
    <arg name="rate"  default="5"/>
    <arg name="decimation"  default="1"/> <!-- Reduce the image size, e.g., 2 means "width/2 x height/2".
  
    <!-- Use same nodelet used by Freenect/OpenNI -->
    <group ns="camera">
      <node pkg="nodelet" type="nodelet" name="data_throttle" args="load rtabmap_ros/data_throttle camera_nodelet_manager" output="screen">
        <param name="rate" type="double" value="$(arg rate)"/>
        <param name="decimation" type="int" value="$(arg decimation)"/>
  
        <remap from="rgb/image_in"       to="rgb/image_rect_color"/>
        <remap from="depth/image_in"     to="depth_registered/image_raw"/>
        <remap from="rgb/camera_info_in" to="rgb/camera_info"/>
  
        <remap from="rgb/image_out"       to="data_throttled_image"/>
        <remap from="depth/image_out"     to="data_throttled_image_depth"/>
        <remap from="rgb/camera_info_out" to="data_throttled_camera_info"/>
      </node>
    </group>      
  </launch>

3. Launch the file:

• $ roslaunch freenect_throttle.launch rate:=5

Remote Client Computer

On the client computer, we will launch rtabmap, rgbd_odometry and rtabmapviz using rtabmap.launch for convenience.

1. [Optional]: To avoid host name resolution issues, set ROS_IP environment variable for the client:

• $ ifconfig
  eth0      Link encap:Ethernet  HWaddr ##:##:##:##:##:##  
            inet addr:192.168.1.2  Bcast:192.168.1.255  Mask:255.255.255.0
  ...
  $ export ROS_IP=192.168.1.2

2. Set ROS_MASTER_URI with the robot IP/hostname:

• $ export ROS_MASTER_URI=http://192.168.1.3:11311

3. Launch rtabmap.launch (Warning with rtabmap_ros 0.10 binaries: Please use the updated launch file on master branch linked here instead of the one installed with the rtabmap_ros 0.10 binaries):

• $ roslaunch rtabmap_ros rtabmap.launch rgb_topic:=/camera/data_throttled_image depth_topic:=/camera/data_throttled_image_depth camera_info_topic:=/camera/data_throttled_camera_info compressed:=true rtabmap_args:="--delete_db_on_start"

4. You should now see mapping in rtabmapviz window.

5. If you open the System Monitor of Ubuntu, you should have something like ~500 KiB/s of bandwidth used:

Advanced

1. If you have already odometry on the robot, you can set arguments visual_odometry:=false and odom_topic:="/odom.

2. For depth image when argument compressed:=true, the image_transport used is compressedDepth. For rgb image, the image_transport used is compressed by default, but you can change its type to theora for example (if available) using rgb_image_transport:=thereo.

3. You can use launch rviz manually or with argument rviz:=true for convenience. If you don't want rtabmapviz, you can disable it using rtabmapviz:=false argument.