LibrePilot Forum

General Category => General Discussion => Topic started by: Jiaxin on March 18, 2022, 10:51:58 pm

Title: Question about ROS connection
Post by: Jiaxin on March 18, 2022, 10:51:58 pm
 :)

Hi guys,

I am the rookie of this controller,

I am now developing RL training for my airship and I already set up the whole environment.

But I am stuck here with

Start the ROS node python script on the command line, please use the following arguments:
--connection=udp://0.0.0.0:40001

and ros disconnection in  HITL simulation window.

Does anyone know how to figure out it?
Title: Re: Question about ROS connection
Post by: TheOtherCliff on March 19, 2022, 09:41:31 am
I have never tried ROS, so I can't advise you.  :(  I know there were 1 or 2 people here in the past that have worked with it.  I will ask around to see if anyone I know can help.

There were some hits from a google search for:
  "ROS" "librepilot"

In particular:
  https://forum.librepilot.org/index.php?topic=3904.0
  https://arxiv.org/pdf/2012.15684.pdf
  https://github.com/robot-perception-group/airship_simulation
  https://githubhot.com/index.php/repo/Ootang2019/LibrePilot
Title: Re: Question about ROS connection
Post by: corvuscorax on March 19, 2022, 02:39:03 pm
:)

Hi guys,

I am the rookie of this controller,

I am now developing RL training for my airship and I already set up the whole environment.

But I am stuck here with

Start the ROS node python script on the command line, please use the following arguments:
--connection=udp://0.0.0.0:40001

and ros disconnection in  HITL simulation window.

Does anyone know how to figure out it?


Hi Jiaxin, I'm the guy who is doing Airships with Librepilot, but I never used the "40001" UDB port. Can you post a link where you got that port/instruction from?

The "official" Librepilot repo (and branch) with the ROS code for Airships is https://github.com/robot-perception-group/LibrePilot/tree/airship_control_noetic
but this whole stuff is still a bit experimental (which is also why it's not yet merged into the main LibrePilot code repo yet)

Nevertheless it does fly, and I'll gladly help you set it up if you like. I need to know what exactly you are trying to do though.

Are you trying to reproduce YuTangs RL code or working on your own implementation?  Do you want to setup a software in the loop simulation or fly an actual airship?

cheers

CorvusCorax

Title: Re: Question about ROS connection
Post by: corvuscorax on March 19, 2022, 02:51:38 pm
ah found it. heh, my bad.

port 40001 is the standard port of the python ROS node in ROS/roshitl/nodes/ros2gcs.py

if you have ROS/roshitl in your catkin_ws/src  you should be able to launch that with

rosrun roshitl ros2gcs.py

Title: Re: Question about ROS connection
Post by: corvuscorax on March 19, 2022, 02:55:03 pm
that being said, that ros node is automatically launched if you use the launchfile for the airship simulation

you can start that with

roslaunch blimp_description blimp_gcs_wind.launch

from https://github.com/robot-perception-group/airship_simulation/tree/noetic