Engineers at the University of South Australia have revolutionized the era of wooden sailboats and developed a way for drones to navigate by starry skies at night using simple, lightweight equipment in areas where GPS signals are not available. did.
If you look at images of older aircraft designed for long-distance flights, if you pull out a magnifying glass or use the image enlarger, you might see a small plastic dome sticking out from the top of the fuselage. In the days before GPS and radio direction finders, airplane navigators used the stars to correct their position.
This principle dates back to the days when ship captains used sextants and similar instruments to observe the sun and stars and, with the help of observatories and chronometers, calculate latitude and longitude to an accuracy of about 1.5 degrees. Let’s go back. Nautical miles (2.8 km).
Not bad when you’re sailing out of sight of land for months at a time.
Navi drone II
For most of the 20th century, nearly the same technology was used by aviators, the only difference being to accommodate the fact that star sights were made from unstable platforms in the sky.
Celestial navigation is still practiced by most sailors and some aviators, but GPS performance has declined, primarily when GPS is unavailable or because local conflicts led the United States to shut down secondary GPS fine-tuning capabilities. This is done as a backup in case. Although it is possible to equip drones with automated systems that automatically perform aiming and calculations, such systems would be highly complex as they would need to compensate for the aircraft’s movement and direction in order to function. . Not only is this more expensive, it also means significantly more weight and power consumption.
To get around this, a team in South Australia used a series of images of the night sky to pinpoint a winged drone’s position to within 4 km (2.5 miles) without the need for external signals or data. We have developed an algorithm that can do this. link.
According to the team, the new strap-down system is lightweight, low-cost, and modular, using ArduPilot running on a Cube Orange flight controller. During the navigation correction, the drone takes multiple images as it flies in a circle around every point on the compass. By comparing the images, the algorithm removes bias and aligns the camera with the drone’s attitude and heading reference system (AHRS).
It is claimed that once completed, the new system could be used not only for military applications, but also for long-term environmental monitoring in remote areas.
UniSA researcher Samuel Teague said: “Unlike traditional celestial navigation systems, which are often complex, heavy and expensive, our system is simpler, lighter and requires no stabilization hardware. It is suitable for small drones.” “This type of navigation is ideal for operations at sea or in combat zones where GPS jamming is dangerous.Apart from the defense sector, it could also be very useful for environmental monitoring.”
The study was published in the journal Drones.
Source: University of South Australia
