Using cartographer for creating map, how??

asked 2017-01-16 08:42:56 -0500

SCrusher
41 ●3 ●5 ●5

Hello, I just installed cartographer package and I am trying to use it in order to create a map and visualise it in rviz. I am using vrep, where I have a robot with laser scan publishing data to laser scan topic and odometry data to odom topic. I am trying to make the cartographer_node to subscribe to these topics and produce the map, just like I did with gmapping before.

However I am lost in the launch files and in how I pass these parameters to cartographer. I am in beginner level. I have read the ros tutorials but still it doesn't make sense. Could anyone provide me with an example of how to do this?

Thanks in advance.

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answered 2017-02-01 21:20:15 -0500

tb12
21 ●3 ●4

I also use a laser scanner but I don't have any odometry data (I assume you mean from your wheels?) and it works fine. Here is my configuration file, which is almost identical to the given backpack_2d.lua file from the demo:

include "map_builder.lua"

options = {
  map_builder = MAP_BUILDER,
  map_frame = "map",
  tracking_frame = "base_link",
  published_frame = "base_link",
  odom_frame = "base_link",
  provide_odom_frame = false,
  use_odometry = false,
  use_laser_scan = true,
  use_multi_echo_laser_scan = false,
  num_point_clouds = 0,
  lookup_transform_timeout_sec = 0.2,
  submap_publish_period_sec = 0.3,
  pose_publish_period_sec = 5e-3,
}

MAP_BUILDER.use_trajectory_builder_2d = true
TRAJECTORY_BUILDER_2D.use_imu_data = false

return options

The configuration file can be called from a launch file as so:

<launch>
  <param name="robot_description"
    textfile="$(find cartographer_ros)/urdf/backpack_2d.urdf" />

  <node name="robot_state_publisher" pkg="robot_state_publisher"
    type="robot_state_publisher" />

  <node name="cartographer_node" pkg="cartographer_ros"
      type="cartographer_node" args="
          -configuration_directory $(find cartographer_ros)/configuration_files
          -configuration_basename backpack_2d.lua"
      output="screen">
     <!--<remap from="echoes" to="scan" />-->
  </node>

  <node pkg="tf" type="static_transform_publisher" name="world_to_map_broadcaster" args="0 0 0 0 0 0 world map 50" />
  <node pkg="tf" type="static_transform_publisher" name="base_to_laser_broadcaster" args="0 0 0 0 0 0 base_link laser 50" />

</launch>

Be sure to configure the simtime somewhere too

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Comments

did you get any errors when you launch it? can you run: rosrun rqt_graph rqt_graph and rosrun rqt_tf_tree rqt_tf_tree after you launch the cartographer node, and post the result.