Lidar on a chip promises to make robotics systems more affordable

The system developed by MIT’s Photonic Microsystems Group could be mass manufactured and cost as little as £7.60 each

Researchers from MIT and the US Defense Advanced Research Projects Agency have developed an affordable light detection and ranging chip no larger than a dime that could push forward developments in self-driving cars, drones and robots.

Autonomous vehicles and robotics rely heavily upon the high image resolution that light detection and ranging (lidar) systems offer to image complex objects or for autonomous navigation. However, wide commercial uptake is limited as high-end systems can cost up to £50,000. 

The lidar-on-a-chip system developed by researchers Christopher Poulton and Michael Watts from MIT’s Photonic Microsystems Group could be mass manufactured and cost as little as £7.60 each. 

Lidar systems work by emitting beams of light and timing how long it takes for the signal to return in order to measure the distance to an object. By steering this transmitted light, multiple points of an environment can be measured to create a full 3D model. Additional information about the object, such as its velocity or material composition, can also be determined by measuring certain properties of the reflected signal, such as the induced Doppler shift. 

Most lidar systems use optical components such as lasers, lenses and external receivers. In order to have a useful 360° field of view, this laser/receiver module is mechanically spun around, often while also being oscillated up and down. However, Poulton said the mechanical apparatus can be bulky and restrict how regularly it can refresh the image it is creating. It may also be unreliable in harsh environments. 

To improve reliability, the lidar chip does not have mechanical parts. The silicon chip is embedded with photonic circuits and achieves non-mechanical beam steering with the use of optical phased arrays. These can control the optical properties of a surface on a microscopic scale, making it possible to steer the direction of light beams without moving parts.

The non-mechanical beam steering has been found to be 1,000 times faster than mechanical lidar systems, and potentially allows for an even faster image scan rate. Poulton said: “This can be useful for accurately tracking small high-speed objects that are only in the lidar’s field of view for a short time, which could be important for obstacle avoidance for high-speed UAVs.”

The on-chip lidar system can detect objects at ranges of up to 2m but is expected to achieve a 10m range by 2017.