Light centimetre-level SLAM for drones

June 01, 2016 // By Julien Happich
Working deeply with CERN (European Centre for Nuclear Research) in 2012, French startup Terabee has taken IR-based time-of-flight (ToF) to centimetre-level, boasting update frequencies up to 1kHz for fast moving robots and drones.

The company's lead product, TeraRanger One, is a 35x29x18mm standalone device weighing only 8 grams. Because the ToF unit only packs three eye-safe IR LEDs and a centrally-designed IR sensor to stream calibrated distances in mm, the static design is more reliable than bulkier rotating laser lidars typically used in Simultaneous Localisation and Mapping (SLAM) robotic applications. Several static sensors are already designed into arrays, linear or circular, for a wider field of view (3º per unit), and a single unit was even mounted onto a motor spindle to emulate a lidar.

The TeraBee One, spider and box versions, and a rotating lidar.

"The original product idea came up from a joint project at CERN, to automate the visual inspection of the Large Hadron Collider's 27km+ tunnel", Commercial Manager Greg Watts told eeNews Europe. The researchers evaluated a number of collision-avoidance technologies to mount on top of a small drone but soon realized that none of what was available on the market was fast and accurate enough to meet their needs, flying through the tunnel and over their complex installations.

With a detection range of 20cm to 14 meters (6m outdoors on the Type A first generation sensor, but now 14m with Type B) and its fast acquisition speed, the TeraRanger One found many other applications since then and is currently being tried by hundreds of customers, according to the company.