A Cheaper Alternative to LiDAR Technology Use in Autonomous Vehicles
Electrical engineers at Stanford have been working on shrinking the mechanical and electronic components found in a rooftop LiDAR system down to a single silicon chip.
The engineers think that their component could be mass-produced for as little as a few hundred dollars, dramatically cutting the cost of LiDAR technology and bringing the autonomous vehicle (AV) industry one step closer to being able to bring to market more affordable options for consumers.
Indeed, this has been a major challenge faced by the industry for years, and researchers have long since been looking for ways to make LiDAR, the technology that enables robotic navigation systems to spot and avoid hazards, cheaper.
Current LiDAR systems are highly complex and make use of lots of mechanical parts and infrared lasers to do their job. They are also highly expensive, coming in at anywhere between $8,000 to $30,000 system. However, the team at Stanford University, led by electrical engineer Jelena Vuckovic, is working on shrinking these components down to the size of a single silicon chip and fabricating them for a fraction of the cost.
In a study published in the journal Nature Photonics, Vuckovic’s team describes how they were able to structure silicon in a way that used its infrared transparency to control, focus, and utilize the power of photons.
A Google self-driving car with a roof-mounted LiDAR system.. Google has since spun off its self-driving car business Waymo, a subsidiary of Alphabet. Image used courtesy of Google
Pioneering Inverse Design
According to the study, the research team used a process that Vuckovic’s lab has spent the past ten-or-so years perfecting—inverse design. This process takes advantage of the fact that silicon is transparent to the infrared laser light used by LiDAR, much like glass is transparent to sunlight.
The inverse design uses a powerful algorithm that puts together a blueprint for the photonic circuits that perform specific functions. In the case of a LiDAR system, firing an infrared beam out ahead of an autonomous vehicle to locate objects and other hazards in the road and routing the refracted light back to a detector.
The LiDAR system is then able to measure the distance between the car and the object or hazard based on the delay between when the infrared light is sent forward and when it is picked up by the detector.
Aiming to Make LiDAR Systems Affordable
It took Vuckovic’s team two years to put together the circuit layout for the LiDAR-on-chip prototype that was built in Stanford’s nanofabrication facility in collaboration with physicists and researchers from the City University of New York.
Vuckovic is hopeful that building this range-finding mechanism on a single chip is the first step toward creating inexpensive LiDAR systems. She and her team are now working on their next milestone—ensuring that the laser beam can sweep in a circle without the use of expensive mechanical parts that are prone to eventual failure, a feat that Vuckovic estimates is around three years away from a road test.