While many countries are experimenting with laser systems such as anti-drone weapons, Professor Li Xuelong and his team of researchers at Northwestern Polytechnical University (NPU) in Xi'an, China, approached the topic from another perspective. Chinese researchers have in fact discovered a way to use high-energy laser beams to remotely power drones, keeping them in the air "virtually forever".
The scientists' initial thesis was that if a drone were equipped with a technology that transforms light into electrical energy, a high-power laser could not only trace its path, but also power it from afar. And the facts proved him right.
The NPU's multidisciplinary team, specializing in artificial intelligence, optics and electronics, said a recent experiment demonstrated how autonomous charging could be combined with intelligent signal transmission and processing technology. Thus offering optical drones (ODDs) virtually unlimited endurance.
A systematic review
Scientists have presented a system that allows drones to be monitored 24 hours a day and have long-range flight autonomy. To achieve this, they developed an algorithm that can detect and track optical drones with precision. And when I say “precision”, I mean despite variations in light, scale and rotation. According to the report, this algorithm was effective in different environmental situations and was able to provide precise positioning of drones.
Li and his team faced a major challenge: How to extend the range of wireless power transmission without losing too much power along the way? Their innovative solution was to use adaptive laser beam shaping technology, which can automatically adjust their intensity to minimize attenuation in the atmosphere.
Thanks to this system, negative impacts caused by air turbulence and density changes in the atmosphere can be reduced. And this makes long-distance energy transmission with laser beams more effective and reliable. Furthermore, a protection algorithm has also been added, which automatically adjusts the laser power to keep it within safe levels in case of obstacles along the path.
The team conducted three successful flight tests: indoor flight, outdoor day flight and outdoor night flight. The drones have proven to perform well in all conditions.
Drones powered by laser beams, possible applications
The research team has kept details about the capability of their new photoelectric conversion system secret. Why? Of course, the technology has potential uses in the military. However, an animated depiction shown in their report suggested that optical drones (ODDs) powered by laser beams could fly up to the height of a skyscraper.
Drones are already widely used in several applications. First of all, unfortunately, military ones: but also agricultural and commercial applications. However, if their limits of resistance are overcome, they could pave the way for new possibilities in the world. We could save precious time during rescue missions, such as searching for tourists trapped in floods. “Eternal” drones are also useful for traffic control, security and contactless logistics.
In the future, large drones could even become aerial buses to build a three-dimensional traffic network. In the meantime, however, I think we will see laser beams at work to power swarms of military drones.
