Flying 3-D Eye-Bots

Intelligent swarms of aerial drones are a universally useful tool for police, crisis managers and urban planners

They can be deployed as additional surveillance resources during major events, or as high-resolution 3D street imaging systems. Intelligent swarms of aerial drones are a universally useful tool for police, crisis managers and urban planners. Special 3D sensors developed by Fraunhofer researchers ensure flawless aerobatics and prevent collisions.

Like a well-rehearsed formation team, a flock of flying robots rises slowly into the air with a loud buzzing noise. A good two dozen in number, they perform an intricate dance in the sky above the seething hordes of soccer fans. Rowdy hooligans have stormed the field and set off flares. Fights are breaking out all over, smoke is hindering visibility, and chaos is the order of the day. Only the swarm of flying drones can maintain an overview of the situation. These unmanned aerial vehicles (UAVs) are a kind of mini-helicopter, with a wingspan of around two meters. They have a propeller on each of their two variable-geometry side wings, which lends them rapid and precise maneuverability. In operation over the playing field, their cameras and sensors capture urgently-needed images and data, and transmit them to the control center. Where are the most seriously injured people? What’s the best way to separate the rival gangs? The information provided by the drones allows the head of operations to make important decisions more quickly, while the robots form up to go about their business above the arena autonomously — and without ever colliding with each other, or with any other obstacles.

A CMOS sensor developed by researchers at the Fraunhofer Institute for Microelectronic Circuits and Systems IMS in Duisburg lies at the heart of the anti-collision technology. “The sensor can measure three-dimensional distances very efficiently,” says Werner Brockherde, head of the development department. Just as in a black and white camera, every pixel on the sensor is given a gray value. “But on top of that,” he explains, “each pixel is also assigned a distance value.” This enables the drones to accurately determine their position in relation to other objects around them.