How to Distinguish Depth Camera Topics for Multiple Drones in Gazebo Harmonic?

PX4 Autopilot Simulation šŸŒ
1

Hello everyone,

Iā€™m currently working on a Gazebo simulation project where Iā€™m running multiple drones, each equipped with a depth camera. In the simulation, all the dronesā€™ cameras are publishing to the same topics, such as /depth_camera and /camera_info. This makes it impossible for me to differentiate between the data from each drone when subscribing to these topics in ROS 2.

Problem:

When multiple drones are running simultaneously in a Gazebo environment, all of their depth cameras publish to the same default topics:

  • /depth_camera (depth image)
  • /camera_info (camera information)

Since all the drones share these topic names, Iā€™m unable to distinguish which data belongs to which drone when processing the information in ROS 2. This creates confusion, especially in multi-drone scenarios where each droneā€™s data should be handled separately.

Proposed Solution:

I suggest that each droneā€™s camera topics should include the model name as a prefix, making it easier to identify data from different drones. For example, each drone could have unique topic namespaces like:

  • /x500_depth_0/depth_camera
  • /x500_depth_0/camera_info
  • /x500_depth_1/depth_camera
  • /x500_depth_1/camera_info

This way, each drone would have its own set of clearly distinguishable topics, preventing any overlap.

2

My startup commands:
python3 simulation-gazebo --world walls
PX4_GZ_STANDALONE=1 PX4_SYS_AUTOSTART=4001 PX4_SIM_MODEL=gz_x500_depth PX4_GZ_WORLD=walls ./build/px4_sitl_default/bin/px4
PX4_GZ_STANDALONE=1 PX4_SYS_AUTOSTART=4001 PX4_SIM_MODEL=gz_x500_depth PX4_GZ_WORLD=walls ./build/px4_sitl_default/bin/px4 -i 1

3

you can find the solution PX4 docs on Multi-Vehicle Sim in gazebo simulation section.

if you are running multi-agent you will need to set up an unique instance for each drone, try to set up two different instance

PX4_GZ_STANDALONE=1 PX4_SYS_AUTOSTART=4001 PX4_SIM_MODEL=gz_x500_depth 
PX4_GZ_WORLD=walls ./build/px4_sitl_default/bin/px4 -i 1

PX4_GZ_STANDALONE=1 PX4_SYS_AUTOSTART=4001 PX4_SIM_MODEL=gz_x500_depth 
PX4_GZ_WORLD=walls ./build/px4_sitl_default/bin/px4 -i 2