px4-offboard

This repository contains a python examples for offboard control on ROS2 with PX4

The px4_offboard package contains the following nodes

• offboard_control.py: Example of offboard position control using position setpoints
• visualizer.py: Used for visualizing vehicle states in Rviz
• velocity_control.py: Example of offboard velocity control based from ROS2_PX4_Offboard_Example
• control.py : Keyboard User input to be sent to velocity control

The source code is released under a BSD 3-Clause license.

• Author: Jaeyoung Lim
• Affiliation: Autonomous Systems Lab, ETH Zurich
• Maintainer: Kyuhyong You

Setup

Add the repository to the ros2 workspace

git clone https://github.com/kyuhyong1/px4-offboard

Running

Start PX4 in simulation

You will make use of 3 different terminals to run the offboard demo.

On the first terminal, run a SITL instance from the PX4 Autopilot firmware.

make px4_sitl gazebo

On the second terminal terminal, run the micro-ros-agent which will perform the mapping between Micro XRCE-DDS and RTPS. So that ROS2 Nodes are able to communicate with the PX4 micrortps_client.

micro-ros-agent udp4 --port 8888

Start PX4 hardware

First you will need to start micro-ros-agent either from the Host PC or Companion computer(CC) depending on how PX4 is connected to.

If CC is connected to PX4 via serial port(/dev/ttyHS1) with baud rate of 2000000,

$ ros2 run micro_ros_agent micro_ros_agent serial --dev /dev/ttyHS1 -b 2000000

Launch Teleop Control

To run the offboard teleop control example, open a terminal and run the the node.

ros2 launch px4_offboard offboard_teleop_control.launch.py

This will launch teleop_keyboard.py which takes keyboard input from user to send Twist command to offboard_commander node.

Available commands as below

• W:  Velocity +Z (Move up)

• X:  Velocity -Z (Move down)

• A:  Velocity +Y (Move Left)

• D:  Velocity -Y (Move Right)

• Arrow Up:  Velocity +X (FWD)

• Arrow Down:  Velocity -X (REV)

• Arrow Left:  Rotate +Z (Yaw Left)

• Arrow Right:  Rotate -Z (Yaw Right)

• S:   Reset velocity to zero

• O:   Set to OFFBOARD mode

• SPACE:  Set ARM

• T:   Set to TAKEOFF mode

• L:   Set to LAND mode

• BACKSPACE:  Set DISARM

Launch offboard_position_control

In order to run the offboard position control example, open a third terminal and run the the node. This runs two ros nodes, which publishes offboard position control setpoints and the visualizer.

ros2 launch px4_offboard offboard_position_control.launch.py

In order to just run the visualizer,

ros2 launch px4_offboard visualize.launch.py