How can I publish images to ROS from PX4 Gazebo SITL

1

Hi, I want to attach a camera sensor on PX4 drone in Gazebo SITL environment, then publish images to ROS. I wrote a Gazebo model sdf file and it works well in…the normal Gazebo. However, in PX4 Gazebo SITL (I ran “make posix_sitl_default gazebo”), it throws an error like below when I add the camera model I wrote.

[FATAL] [1497522126.103665066]: A ROS node for Gazebo has not been initialized, unable to load plugin. Load the Gazebo system plugin ‘libgazebo_ros_api_plugin.so’ in the gazebo_ros package)

How can I attach cameras that be able to publish images to ROS on PX4 drones in Gazebo?

2

Oops sorry it was on the developer’s documents.
The last section “What’s happening behind the scenes” in
https://dev.px4.io/en/simulation/ros_interface.html

3

Hi. I’m really new to px4, gazebo and ros. I followed the link that you posted. I ran the typhoon_h480.world and checked ros topics with ‘rostopic list’. However, I didn’t see any topics related to images.

I guess I’m not fully understanding the whole structure yet.
Could you please describe how you published images to ros from px4 Gazebo SITL?

4

@Keunwoo_Park How are you starting the ROS node? You need to republish the udp video stream in ROS to be able to see it in ros

1 Like
5

I figured out. iris_fpv_cam model worked instead of typhoon_h480.

Camera in typhoon_h480 model uses GeotaggedImagesPlugin. And the topic name isn’t assigned to the plugin. However, fpv_cam has a topic name (imageTopicName). So I could get images by RViz, when I used iris_fpv_cam.

6

Right…

  • iris_fpv_cam uses the gazebo_ros_camera plugin, which publishes images to ROS
  • The typhoon_h480 uses the gst_camera_plugin which streams video using gstreamer over a udp sink.

Now I see that the fpv_cam model name is not that obvious that it is a ros specific camera model.

1 Like