gisnav-mock-gps-demo.mp4

Introduction

Warning Do not use this software for real drone flights. GISNav is untested and has only been demonstrated in a simulation environment.

GISNav is a ROS 2 package that enables map-based visual navigation for airborne drones in a simulation environment.

GISNav provides a precise global position by visually comparing frames from the drone's nadir-facing camera to a map of the drone's approximate global position retrieved from an onboard GIS system.

Mock GPS Example

The below steps demonstrate how GISNav enables GNSS-free flight with PX4 Autopilot's Mission mode in a SITL simulation.

You will need to have the Docker Compose plugin and NVIDIA Container Toolkit installed.

Install GISNav CLI

The GISNav CLI (gnc) is a Docker Compose wrapper that significantly simplifies building and deploying GISNav's Docker Compose services. It is packaged as a Debian distributable.

Create the Debian distributable and install gnc from it using the following commands:

git clone https://github.com/hmakelin/gisnav.git
cd gisnav
make install

Build and run SITL simulation

Build the Docker images and create and run the containers (downloading and building everything will take a long time):

Note

• This script will automatically expose your X server to the created Docker containers to make the GUI applications work.
• We stop autoheal because current healthchecks are quite naive and often flag healthy services as unhealthy.
• Gazebo in the px4 service will on first run download a number of models and will be slow to start up (on first run).
• mapserver service will on first run transfer some files to a shared volume and will be slow to start up (on first run).

gnc build px4 gisnav --with-dependencies
gnc create px4 gisnav
gnc start px4 gisnav && gnc stop autoheal

Upload flight plan via QGroundControl

Once both the Gazebo and QGroundControl windows have appeared (QGroundControl should show the drone location near San Carlos airport), use QGroundControl to upload the sample ~/ksql_airport_px4.plan flight plan that is included inside the Docker container, and then start the mission.

Simulate GPS failure

Wait until the drone has risen to its final mission altitude. You can then try disabling GPS through your MAVLink Shell (accessible e.g. through QGroundControl > Analyze Tools > MAVLink Console):

failure gps off

The drone should now continue to complete its mission GNSS-free with GISNav substituting for GPS.

You can check if PX4 is receiving the mock GPS position estimates by typing the following in the MAVLink shell:

listener sensor_gps

Note The gisnav service will by default send uORB messages to PX4 via the micro-ROS agent which bypasses the GPS driver so you will not see the GPS status with commands like gps status.

Finally, you can stop all simulation services with the below command:

gnc stop

Documentation

See the latest developer documentation for information on how to setup a local environment for GISNav development, for code examples and API documentation, and integration examples.

License

This software is released under the MIT license. See the LICENSE.md file for more information.