For autonomous vehicles, fewer sensors may be more.
The best autonomous vehicles today typically rely on three main types of sensors: cameras, radar, and lidar (similar to radar, but using lasers instead of radio waves). But a new type of lidar could eliminate the need for radar while also being more accurate, improving a car’s awareness of its surroundings and potentially trimming the total cost of its sensor package.
Uber’s test autonomous vehicles relied in part on pulsed lidar units perched atop the sensor bar to place themselves in their surroundings.
Today, the lidar systems that many autonomous vehicles use send out pulses of laser light—as many millions every second—and read the reflected light to determine the distance between itself and other objects. But the new sensor, called continuous-wave lidar, uses a continuous laser beam rather than a pulse to do the same. It’s similar in principle to how radar operates. As a result, it can more accurately gauge distance and speed in one package.
In the last few years, researchers at universities and companies have been exploring continuous-wave lidar, including those at Aeva, a startup founded by two alumni of Apple’s Special Project’s Group. Here’s Cade Metz, reporting for the New York Times:
“I don’t even think of this as a new kind of lidar,” said Tarin Ziyaee, co-founder and chief technology officer at the self-driving taxi start-up Voyage, who has seen the Aeva prototype. “It’s a whole different animal.”
Aeva reportedly aims to sell the new sensor next year, though there’s no word on how much it will cost. At around $70,000–$80,000 for a main unit, lidar is currently among the most expensive components in self-driving cars. Continuous-wave lidar sensors could help trim costs by eliminating the need for radar units, but their price would have to be on par with current lidar units to achieve any significant savings. (Radar units run about $10,000.)
Even if they are more expensive, continuous-wave lidar sensors could still win out given their accuracy. Recent research suggests that continuous-wave lidar is not only more accurate, but it also senses objects over longer distances, two qualities that autonomous vehicles will need in order to operate safely.