px4_ros_offboard

This package provides ROS2 nodes for controlling drones via PX4's Offboard control. It supports two modes: velocity control and altitude hold control. Users can operate the drone using either a keyboard or a joystick. For keyboard input, the keyboard_joy package is required, while for joystick input, the standard ROS joy node is used.

Dependencies

Ensure the following dependencies are installed before running the launch files:

• keyboard_joy (for keyboard-based control)

  • Repository: keyboard_joy

• joy (for joystick-based control)

  • Install the joy package for joystick input:

    sudo apt-get install ros-<your-ros-distro>-joy

Installation

Follow these steps to install the required packages:

# Create a new workspace
mkdir -p your_workspace/src
# Navigate to the new src folder
cd ~/your_workspace/src
# Clone the keyboard_joy repository
git clone https://github.com/atarbabgei/keyboard_joy.git
# Clone the px4_ros_offboard repository
git clone https://github.com/atarbabgei/px4_ros_offboard.git
# Build the workspace
cd ~/your_workspace
colcon build

Launch Files and Usage

1. velocity_control.launch.py

This launch file starts the velocity_control node.

Example Commands

• To launch with keyboard input:

  ros2 launch px4_ros_offboard velocity_control.launch.py input:=keyboard use_world_frame:=false

• To launch with joystick input:

  ros2 launch px4_ros_offboard velocity_control.launch.py input:=joystick use_world_frame:=true

2. manual_control.launch.py

This launch file starts the manual_control node, which mimics the manual control mode in PX4.

Example Commands

• To launch with keyboard input:

  ros2 launch px4_ros_offboard manual_control.launch.py input:=keyboard

3. altitude_hold_control.launch.py

This launch file starts the altitude_hold_control node, which implements a PID loop for altitude hold.

Example Commands

• To launch with keyboard input:

  ros2 launch px4_ros_offboard altitude_hold_control.launch.py input:=keyboard

4. position_control.launch.py

This launch file starts the position_control node, which updates the position setpoint in PX4's world frame (NED) based on /joy input.

Example Commands

• To launch with keyboard input:

  ros2 launch px4_ros_offboard position_control.launch.py input:=keyboard

Parameters

• input: Selects the input method, either 'keyboard' or 'joystick'. Default is 'keyboard'.

• use_world_frame (used only in velocity_control.launch.py): Determines whether to use the world frame (NED) or the vehicle-relative frame (FLU). The default is 'false' (FLU frame).

Configuration Files

The package includes configuration files for both keyboard and joystick input located in the config directory:

• joy_config.yaml (for joystick input)
• keyboard_joy_config.yaml (for keyboard input)

These configuration files are automatically selected based on the input argument.