Apple has held preliminary discussions with four unnamed suppliers of LiDAR sensors for self-driving vehicles. That might indicate that the Cupertino giant has rebooted its self-driving hardware, code-named Project Titan, although the sensors could also be for the vehicles used in the company’s in-house shuttle service for employees.

Reuters has the story:

Apple is seeking LiDAR units that would be smaller, cheaper and more easily mass produced than current technology. The iPhone maker is setting a high bar with demands for a ‘revolutionary design,’ one of the people familiar with the talks said.

While Tim Cook & Co. are evaluating the companies’ technology, they’re also continuing work on Apple’s own LiDAR unit, three sources said. One of the sources speculated that the sensor effort means Apple is doubling down on autonomous driving hardware.

What is clear from Apple’s interest in cheaper LiDAR systems is that it wants to control the ‘perception stack’ of sensors, computers and software to drive an autonomous vehicle, regardless of who makes the vehicle, another person familiar with the talks said.

Apple wants a “design-oriented” sensor that would see several hundred meters down the road and be unobtrusive enough to fit into the overall lines of a vehicle.

Apple gets ‘a lot of optionality by working on the perception stack,’ said the second person familiar with the talks. ‘Bringing a passenger car to the market is really, really hard, and there’s no reason right now they need to jump into it.’

LiDAR is a method of measuring distance by illuminating a target with pulsed laser light and measuring the reflected pulses with a sensor. Differences in laser return times and wavelengths can then be used to make the target’s digital representation in 3D.

LiDAR sensors mounted atop Apple’s Maps surveying vehicles

Reuters says Apple needs sensors that can provide a detailed 3D look at the road. LiDARs play a crucial part in autonomous driving, but they’re expensive ($100,000), bulky and prone to failure because they require mechanical parts to sweep the laser scanners across the road.

It’s said that the Cupertino company has been using Lexus SUVs outfitted with as many as six Velodyne-made LiDAR sensors to test its autonomous driving software.

Recent reports have indicated that the iPhone maker has sharply increased its road testing while bringing on key hires from Google and Tesla.