PX4 Community Q&A: February 08, 2023

February 08, 2023

Join us

Agenda

  • Community Announcement
  • Community Q&A
  • General Discussions

:loudspeaker: Community Announcement


A.1 : Change of Format to Dev-call

As announced last call, the weekly Wednesday call is a Community QnA time now.

:people_holding_hands: Community Q&A (No deep technical discussions)


:exclamation: Guideline for asking a Question

  1. Specify what you are trying to achieve
  2. Specify what environment / platform you are using
  3. Prepare a Link or Document to help understand if possible
  4. First, ask the question on Discord or create a Github Issue!
  5. If you take over 5 minutes for the question, please continue in Discord or a Github Issue.

Q.1 : Can we say that Ubuntu 22.04 is fully supported?

  • Currently it works well with PX4 Development environment
  • Just ROS2 documentation is not up to date

TODO: Follow up on ROS2 documentation & get main document updated.

Q.2: Which Gazebo version should be kept in Ubuntu 22?

  • Ignition Fortress (11) > Gazebo Garden migration
  • To run Gazebo 11, it would be better to run in Docker, according to Gazebo documentation, Ubuntu 22 shouldn’t be supporting Gazebo 11
  • For Ubuntu 22.04, the only supported Gazebo is ‘Garden’ (== ‘gz’).

TODOs

Q.3: Propwash modeling in Gazebo - Harshil

Implementing it for simulating a duo-tailsitter in SITL (another thing which is not stock supported).

  • Have been trying to implement prop-wash dynamics in lift-drag plugin of Gazebo
  • Modifying the PX4 Gazebo SITL repo’s lift-drag plugin directly.
  • Using Gazebo 9 (classic)

Answer: Try to upstream this (to OSRF repo), and use the model in the .sdf file.

  • How to model the prop-wash?

Have conducted literature survey, and for now using Near Field Approximation would be feasible.

Action Item: Will update on the progress when it gets upstream-able.

Q.4: Running Gazebo & PX4 instance separately - Josh

Current documentation doesn’t really work: Gazebo Simulation | PX4 User Guide

Solution: Just run the px4 binary in the build folder with the environment variables are given to it directly.

Try this script: sim_gazebo_bringup/sim_gazebo.launch.py at 587d33d8de0e290b5662c88b3414a1a191e87800 · rudislabs/sim_gazebo_bringup · GitHub

TODO: Would be nice when this is figured out, to create a PR on PX4 Docs

Q.5: How to do flight testing effectively? - Harshil

Currently, testing via Mission plans in SITL. How are the ‘tests’ (e.g. Mavsdk) used?

  • Functional Test: MAVSDK driven mission flight tests exist

Try this doc out: Integration Testing using MAVSDK | PX4 User Guide

How to improve Simulation speed?

:thinking: General Discussions


D.1 : Preflight check rework prevents takeoff with Optical Flow - Alex

D.2 : Pixhawk Carrier board with Jetson Nano - Alex

  • What kind of features would be desired?
  • What kind of connectors should be broken out from Autopilot / Jetson, etc?
  • Currently MIPI Camera connectors will all be broken out (Jetson): 4x
  • Break out as many USB-C as well (for multiple camera connection)
  • Storage: SD card slots exist? / may differ for production models (will check different Jetson Nano form-factors compatibility)
  • Would like to have vision based position mode flight demo

I have two questions:

1 .Can we say that Ubuntu 22.04 is fully supported?
2. About the transition gazebo11gazebo-classic and it’s “incompatibility” with gazebo garden in Ubuntu 22, is it possible to reach an agreement on which version to keep as default in the install script?

From Discord:

harshil_airbound — Today at 8:11 AM
I have a question (sorry for not posting it on the forum)

Are there existing plans to include propwash models for vehicles like tailsitter? If not, would anyone be interested in working with me to build one?
I’m implementing it for simulating a duo-tailsitter in SITL (another thing which is not stock supported)
Thanks!
Also, if I could get some ideas from everyone about how they would go about doing this.