Researchers at the University of Zurich, the Università della Svizzera italiana, and the University of Applied Sciences and Arts of Southern Switzerland have developed software that enables drones to autonomously detect and follow forest paths to find missing persons.
Every year, the researchers explain, thousands of people lose their way in forests and mountain areas. However, drones can effectively complement the work of rescue services teams. Because they are inexpensive and can be rapidly deployed in large numbers, unmanned aircraft can substantially reduce the response time and the risk of injury to missing persons and rescue teams alike.
A group of researchers from the Dalle Molle Institute for Artificial Intelligence and the University of Zurich has developed artificial intelligence software to teach a small quadcopter to autonomously recognize and follow forest trails. In turn, the drones could soon be used in parallel with rescue teams.
“While drones flying at high altitudes are already being used commercially, drones cannot yet fly autonomously in complex environments, such as dense forests. In these environments, any little error may result in a crash, and robots need a powerful brain in order to make sense of the complex world around them,” says Professor Davide Scaramuzza from the University of Zurich.
The drone used by the Swiss researchers observes the environment through a pair of small cameras, similar to those used in smartphones. Instead of relying on sophisticated sensors, the drone uses powerful artificial-intelligence algorithms to interpret the images to recognize man-made trails. If a trail is visible, the software steers the drone in the corresponding direction.“Interpreting an image taken in a complex environment such as a forest is incredibly difficult for a computer,” says Dr. Alessandro Giusti from the Dalle Molle Institute for Artificial Intelligence. “Sometimes even humans struggle to find the trail!”
The Swiss team solved the problem using a so-called “deep neural network,” a computer algorithm that learns to solve complex tasks from a set of training examples – much how a brain learns from experience.
In order to gather enough data to train the algorithms, the team hiked several hours along different trails in the Swiss Alps and took more than 20 thousand images of trails using cameras attached to a helmet.
According to the researchers, the effort paid off: When tested on a new, previously unseen trail, the deep neural network was able to find the correct direction in 85% of cases; in comparison, humans faced with the same task guessed correctly 82% of the time.
Professor Juergen Schmidhuber, scientific director at the Dalle Molle Institute for Artificial Intelligence, adds, “Our lab has been working on deep learning in neural networks since the early 1990s. Today I am happy to find our lab’s methods not only in numerous real-world applications such as speech recognition on smartphones, but also in lightweight robots such as drones. Robotics will see an explosion of applications of deep neural networks in coming years.”
The research team warns that much work is still needed before a fully autonomous fleet will be able to swarm forests in search of missing people.
Professor Luca Maria Gambardella, director of the Dalle Molle Institute for Artificial Intelligence in Lugano, remarks, “Many technological issues must be overcome before the most ambitious applications can become a reality. But small flying robots are incredibly versatile, and the field is advancing at an unseen pace. One day, robots will work side by side with human rescuers to make our lives safer.”
The research was supported by the Swiss National Science Foundation through the National Centre of Competence in Research Robotics.