Self-driving cars could be made safer by a device that can fit in the palm of your hand.
Scientists have developed a compact, non-mechanical version of lidar, a light radar.
It is cheaper and more reliable than current alternatives – and overcomes obscuring of black cars which don’t reflect light.
The device measures the time for the beam to return to the receiver.
Data is then processed to create three-dimensional representations of the surrounding area.
It’s like radar only using light waves that produce crisper scans.
Lead author Dr. Susumu Noda, of Kyoto University in Japan, said: “With our lidar system, robots and vehicles will be able to reliably and safely navigate dynamic environments without losing sight of poorly reflective objects such as black metallic cars.
“Incorporating this technology into cars, for example, would make autonomous driving safer.”
It overcomes current limitations. Lidar uses pulsed lasers to map objects and scenes – enabling robots, vehicles and drones to navigate their environment.
The new system represents the first time that the capabilities of conventional beam-scanning has been combined with a 3D approach known as flash lidar.
The study in the journal Optica found it can be used to measure the distance of poorly reflective objects such as dark vehicles – and automatically track their motion.
Noda and colleagues say the key is a chip-based light they created named DM-PCSEL (dually modulated photonic-crystal laser).
He explained: “The DM-PCSEL integrates non-mechanical, electronically controlled beam scanning with flash illumination used in flash lidar to acquire a full 3D image with a single flash of light.
“This unique source allows us to achieve both flash and scanning illumination without any moving parts or bulky external optical elements, such as lenses and diffractive optical elements.”
Lidar illuminates objects with beams – calculating the distance by measuring time of flight (ToF) – how long it takes to travel, be reflected and then return to the system. Most scanners rely on moving parts.
Flash lidar simultaneously illuminates and evaluates the distances of all objects in the field of view with a single broad, diffuse beam of light.
But current systems don’t work on black cars for instance due to the very small amount of reflection. They also tend to be large because of the external lenses and optical elements needed to create the flash beam.
DM-PCSEL has both a flash that can illuminate a wide field of view and a beam scanner.
Incorporating it into a 3D lidar system allowed the researchers to measure distances simultaneously – including dark objects.
The researchers also installed a ToF camera and software that enables automatic tracking of poorly reflective objects.
Noda said: “Our DM-PCSEL-based 3D lidar system lets us range highly reflective and poorly reflective objects simultaneously.
“The lasers, ToF camera and all associated components required to operate the system were assembled in a compact manner, resulting in a total system footprint that is smaller than a business card.”
The researchers demonstrated the new lidar system by using it to measure the distances of poorly reflective objects placed on a table in a lab
They also showed the system can automatically recognize poorly reflective objects and track their movement using selective illumination.
The researchers are now working to demonstrate the system in practical applications, such as the autonomous movement of robots and vehicles.
They also want to see if replacing the ToF camera with a more optically sensitive single-photon avalanche photo diode array would allow the measurement of objects across even longer distances.
The government is planning to roll out self-driving vehicles on UK roads by 2025 – sparking a transport revolution to improve road safety and better connect communities
An estimated 38,000 new jobs could be created from the predicted £42 billion ($51 billion USD) industry – backed by £100 million ($121 million USD) of investment into safety developments.
Produced in association with SWNS Talker.
