Over the weekend, electric-car maker Tesla Motors (NASDAQ:TSLA) announced a major upgrade to its Autopilot technology, a driver-assist system with features like automatic steering, lane changing, and braking. While it included a wide range of new features, the most noteworthy improvement is undoubtedly Tesla's shift to a greater reliance on its vehicles' radar sensors for signal processing.

Model S. Image source: The Motley Fool.

A bet on radar

Central to Tesla's 8.0 update is radar's new role as the primary control sensor alongside Tesla vehicles' vision system -- the camera that currently plays the primary role for image processing for the Autopilot system.

"The radar was added to all Tesla vehicles in October 2014 as part of the Autopilot hardware suite, but was only meant to be a supplementary sensor to the primary camera and image processing system," Tesla explained in a Sept. 11 blog post. "After careful consideration, we now believe it can be used as a primary control sensor without requiring the camera to confirm visual image recognition."

During a question-and-answer session with press, Tesla CEO Elon Musk emphasized that radar would not be replacing the vision system as the primary input for signal processing but rather giving the sensor a star role alongside the current vision system.

Radar's greater role in Tesla's Autopilot system is particularly notable because, unlike its vision system, radar can see through "most visual obscuration," Tesla explained. The net result? A Tesla "should almost always hit the brakes correctly even if a UFO were to land on the freeway in zero visibility conditions." Yes, folks: Even a UFO can be avoided.

Tesla continued:

Taking this one step further, a Tesla will also be able to bounce the radar signal under a vehicle in front -- using the radar pulse signature and photon time of flight to distinguish the signal -- and still brake even when trailing a car that is opaque to both vision and radar. The car in front might hit the UFO in dense fog, but the Tesla will not.

Model S dash displays what the car sees. Image source: Tesla Motors.

Notably, Autopilot's growing dependence on radar continues to separate Tesla from other automakers' and tech names' (namely Alphabet) increasing confidence in LiDAR (light detection and ranging) technology as an integral player in the future of autonomous driving. Last month, for instance, Ford (NYSE:F) invested $75 million in sensor company Velodyne LiDAR, the maker of compact, advanced LiDAR products capable of delivering accurate 3D data in real time. Ford anticipates using LiDAR as a key part of its future autonomous vehicle systems in production vehicles.

"From the very beginning of our autonomous vehicle program, we saw LiDAR as a key enabler due to its sensing capabilities and how it complements radar and cameras," said Ford product lead and CTO Raj Nair when the company announced its investment in Velodyne in August. 

But during Tesla's question-and-answer session with press, Musk continued to doubt LiDAR's usefulness in autonomous driving.

"We do not anticipate using LiDAR," Musk said. He went on to explain how the technology can't see through rain, snow, dust, and fog the way radar does. "... So the obvious thing is to use radar and not use LiDAR," Musk said.

It's about safety

Tesla spent a good portion of its conference call with press focusing on the importance of Autopilot's role in increasing driving safety.

The update marks a "dramatic improvement in the safety of the vehicle," Musk said. Going further, he asserted that the improvements will make Tesla vehicles "by far" the safest on the road.

Model S. Image source: The Motley Fool.

The safety of Tesla's Autopilot came into the spotlight in June when Tesla announced the National Highway Traffic Safety Administration's preliminary evaluation of a fatal crash that occurred in a Tesla vehicle while Autopilot was engaged.

This new use of radar as a primary control sensor would have likely prevented the fatal crash earlier this year, Musk said.

This Autopilot update also addresses another important safety concern: the complacency that experienced Autopilot users can develop when the technology is activated. In a roundabout way of penalizing drivers who don't use Autopilot correctly, Tesla said Autopilot will "not allow reengagement of Autosteer until parked if user ignores repeated warnings [to grab the wheel]."

Tesla plans to make Autopilot version 8.0 available to customers via an over-the-air software update in about two weeks.

This is a particularly important update, as it could help simultaneously mitigate negative connotations with Autopilot following the recent high-profile fatal crash and boost Autopilot's value proposition as a selling point for the vehicles. This, of course, assumes Autopilot 8.0 enhances the driver-assist experience in Tesla vehicles as much as the company expects it will.

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