Guardian Optical Technologies, a computer vision startup based in Tel Aviv, Israel, today announced a $3.1 million funding round led by the Toyota-backed Mirai Creation Fund, Goldbell Investments, and Translink Capital. Using camera technology that can detect motion as faint a micrometer, it aims to develop an in-car platform that improves passenger safety.

“Passenger-aware vehicles are becoming more of a necessity as technology in the automotive sector becomes more advanced,” Gil Dotan, CEO of Guardian Optical Technologies, said in a statement.

Guardian Optical’s sensor can record high-resolution videos and three-dimensional depth maps simultaneously, making it well-suited for monitoring young children in the backseats of cars. And thanks to machine learning algorithms, it can estimate the size of each passenger, allowing it to, for example, adjust the force of an airbag’s deployment in the event of a collision.

Another potential application is passenger tracking in self-driving cars, Dotan explained in a phone interview. The camera can detect when riders come aboard, and even pinpoint the door through which they entered. “We can classify people and objects inside the cabin without direct line of sight,” he said.

The startup took pains to keep costs low. The most expensive component is the processor, and Dotan said that it would be “cost-effective” if pitted against comparable solutions. In fact, because it obviates the need for special sensors in seat belts, air cushions, and elsewhere, he projects it could save the auto industry $200 million a year.

Luckily for Guardian Optical, there isn’t much competition in the in-car computer vision market. Owl, an always-on camera that mounts to a car’s rearview mirror, is designed to monitor for break-ins and collisions, not ambient movement. And Nauto‘s in-car monitoring solution, which is intended to prevent distracted driving, is aimed exclusively at the fleet management sector.

In the future, Dotan sees the sensor in buses, trains, and other forms of commercial and public transportation, providing real-time occupancy maps and flagging behaviors like vandalism and violence.

“Monitoring the interior of a cabin is a key component to ensuring safety and an optimized experience for passengers,” Dotan said.

Guardian Optical was founded in 2015. During its last funding round in December 2017, it raised $5.1 million through Mirai Creation.