Overview

This is a ROS2 package for GPS Waypoint navigation with velocity commands. The package was initially developed for a DJI Mavic 3E drone, but it can be used with any drone as long as the ROS Topics are respected.

Build Environment

• Ubuntu 20.04
• ROS2 Humble

Features

• Receives the drone's current GPS location with heading.
• Recevies the drone's home GPS coordinate.
• Receives the goal GPS coodinate with heading.
• Publishes velocity commands for navigating the drone to reach the goal GPS coordinate.
  • The drone takesoff and reaches a height of 60m.
  • Then, the drone orients itself toward the waypoint Long. and Lat.
  • Then, generates linear velocity to reach the Long. Lat., while also correcting the heading on its way.
  • After reaching the Long. Lat., the drone orients towards the goal heading.
  • At last, the drone decends to the goal Altitude.
  • After reaching the Goal waypoint, another waypoint can be published or return home can be triggered.
• Can trigger return home.

Topics Subscribed

• /mavic_1/GPS2: GPS Topic containining Longitude, Latitude, Altitude, and Heading (+ve degrees from North)

  • Type: Float64MultiArray
  • Data: 'longitude': msg.data[0], 'latitude': msg.data[1], 'altitude': msg.data[2], 'heading': msg.data[3]

• towereye_wp: Target GPS Waypoint

  • Type: Float64MultiArray
  • Data: 'longitude': msg.data[0], 'latitude': msg.data[1], 'altitude': msg.data[2], 'heading': msg.data[3]

• setOriginLocation: Drone Home GPS coordinate

  • Type: Float64MultiArray
  • Data: 'longitude': msg.data[0], 'latitude': msg.data[1], 'altitude': msg.data[2], 'heading': msg.data[3]

• /mavic_1/return_home: Topic to trigger retur home

  • Type: Empty

Topics Published

• /mavic_1/cmd_vel: Velocity commands for navigation

  • Type: geometry_msgs/Twist

• /mavic_1/land: Trigger Autoland

  • Type: Empty

Files in the package

• gps_waypoint_nav.py: The main Python ROS2 node responsible for navigation.
• gps_wp_controller.py: The launch file for the package.
  • Launches the gps_waypoint_nav.py node.
  • Launches the image_transport ROS2 package's republish node to subscribe to the ROS2 image topic of encoding ffmpeg, and decode and publish a raw image on a new ROS2 topic.
  • Launches the rqt_image_view ROS2 package's rqt_image_view node to visualize the raw image topic.
  • Launches 3 topic_tools ROS2 package's relay nodes to republish the ROS2 topics coming from the VPN to the host.

How to run

• Clone the repo to your ROS2 workspace.
• Use rosdep to satisfy the dependencies.
• Build the package.
• Source the builds.
• Launch the gps_wp_conteroller.py launch file.

Notes

• Use the DroneWaypointNavigator class variables in the gps_wp_controller.py node to cofigure the behavior.
• The relay nodes in the launch are includes due to the use of a VPN for remote operations. Correctly configure the VPN.
• Example DDS configuration file is included in the dds_config folder.