25 Apr 19

Elon Musk is crazy to dismiss lidar for autonomous cars - or is he?

Earlier this week, Tesla CEO Elon Musk announced his company’s plans on autonomous cars, claiming Tesla would bring its first robotaxis onto the streets by 2021. His disparaging remarks about lidar, however, were not endorsed by most industry insiders.

Let’s recap. Tesla will offer its first cars sans pedals or steering wheel in 2021, and advancements in self-driving technology were largely attributed to a new computer chip Tesla started using. Also, Mr Musk referred to lidar as “a fool’s errand”, going on to say that “anyone relying on lidar is doomed”.

Now, researchers from Cornell University have announced a paper that will be presented in June, Pseudo-Lidar from Visual Depth Estimation: Bridging the Gap in 3D Object Detection for Autonomous Driving. In this paper, they posit that Mr Musk’s may have a point when he prefers cheaper cameras over more expensive lidar.

What is lidar anyway?

Lidar equipment, often installed atop car roofs, uses low-intensity, non-harmful and laser beams that are invisible to the human eye. These beams are pulsed all around the vehicle and the reflected pulses are measured for return time and wavelength to compute the distance of the object from the sender.

In practice, lidar produces very detailed and very high-resolution 3D visualisations of a self-driving car’s surroundings, which is why most companies working on autonomous driving technology are relying heavily on them.

Why does Elon Musk hate lidar?

Lidar, Mr Musk has said repeatedly, is expensive, ugly and unnecessary. He also points out that lidar cannot recognise road signs.

Tesla has never followed the industry standard practice of launching car model years, with each year receiving various design and technological updates. Instead, Tesla prefers implementing incremental improvements as soon as they are available and validated. In many cases, new features are unlocked by over-the-air updates.

Ideally, Tesla wants to unlock a level 4 self-driving mode with such an over-the-air update. Considering Teslas do not come with lidar installed, that precludes AV technology that relies on lidar.

What does he want to use instead?

All Teslas are equipped with a series of cameras that capture images of what’s happening around the car. These cameras are much cheaper to produce and install, they don’t require a lidar dome on the roof of the car and Mr Musk is convinced he can make them work for self-driving technology.

Most competitors do not agree cameras can do that, pointing out that the images are often distorted and distances are hard to compute.

And what do the Cornell researchers say?

In their paper, researchers from Cornell detail a potential breakthrough for cameras in AVs. Basically, installing cameras higher than near a car’s bumper where they are traditionally installed, results in much better and more useable images. Placing cheap cameras behind the windscreen produces stereoscopic images that can be converted to 3D data. From their research, the researchers conclude that these systems can be nearly as precise as lidar, at a fraction of the cost.

More research is needed to develop this technology into something that can lead to the application Tesla is aiming for, but Mr Musk may have been onto something. If so, this could bring self-driving cars within reach of many more potential buyers.

Of course it remains to be seen whether he will meet his self-imposed 2021 deadline.

Image: Better keep your hands on the steering wheel just now, Madam.

Authored by: Benjamin Uyttebroeck