There there is big discussion on use of LIDAR technology. Elon claims all other competitors are morons (a little more direct than that) for using LIDAR technology, though WYAMO and others continue to use it. I am sure the others have analyzed the pros and cons of LIDAR vs the Tesla approach and made a decision. They are not that foolish to go for something if they did not have some hard analysis.
Tesla definitely has a lot of real data from thousands of cars on the street, but so do others. In the usual Elon arrogance, he dismisses anyone who is a competitor. While he has been pretty successful with his approach and bravado, there may be better ideas elsewhere from which he can learn from. As they say pride comes before a fall.
Disclaimer: Let me say right up front that all that I know about driving autonomy, and systems such as radar, lidar, and using software for optical object recognition in video images, is book-learning, rather than any experience I've had. So take my assertions on the subject with a pinch of salt. Now, with that being said...
I think Elon had a very good argument against lidar in Tesla's recent "Full Self Driving" presentation. I think he had some very good points about there being too much overlap between lidar and video cameras; they both depend on the visible light wavelength of the electromagnetic spectrum, and they both can be blocked by such things as fog and heavy rain.
What Elon seemed to be purposefully eliding, though, was the advantage of active scanning for making a 3D map of the environment. Using either lidar or radar to "ping" an object, detecting its shape and exact distance, requires far less computer processing and is far more reliable -- and faster -- than trying to use software to laboriously use number-crunching to match a grayscale image, pixel by pixel, in the hope that the software will be able to identify an object in the frame of video.
They spent a lot of time during the presentation talking about how much more advanced their new computer motherboard is, and how much more advanced the chips on it are; and completely ignored the fact that if they were using active scanning for the primary sensors, instead of cameras, then they wouldn't need such a powerful, expensive computer motherboard.
I'll repeat my claim that phased-array radar, so-called "high-res" radar, would be best for most of the sensor needs of a fully autonomous car. Yes, Elon is correct to say that all of the traffic signs, lights, lane markings, etc. are designed for human sight, and thus cameras are the best system to use for an autonomous car to "see" them. So yes, autonomous or even semi-autonomous cars do need cameras.
The fallacy is in trying to use them for everything. As I understand it, Elon's argument boils to this: Because autonomous cars need cameras to "see" certain things, they have to have cameras. But we shouldn't need a second primary/ long-range sensor system, since humans can drive cars using sight alone.
Yeah, well there's a pretty big fallacy there: If humans were so great a driving safely, then why do we need autonomous cars? The fact is that humans are not such safe drivers. And part of the reason we're not, is that we are almost entirely dependent on human eyesight. We're blind at night, and we can't see thru fog or smoke. Furthermore, we don't have the ability to build up in our minds an accurate 3D map of the environment. We can only look in one direction at a time, and altho we can gauge distance to some extent, we can't do it very accurately.
Our eyesight is also degraded in certain conditions such as fog, heavy rain and heavy snow.
There is a reason why Waymo's self-driving cars use three sensor systems: Cameras, lidar, and some form of radar. What kind of radar is Waymo using? Well, here's how Waymo describes it:
Conventional automotive radars have a narrow field of view and typically only track forward moving cars. In contrast, Waymo’s custom radar system has a continuous, 360 degree view, so it can track objects and vehicles usually hidden from the human eye. Our radars are capable of monitoring a vehicle as it comes up from behind and as it moves out in front of us without any interruption.
They also complement our other sensors by being highly effective in rain, fog or snow. Conventional radars have been designed to focus solely on vehicle movements. However, our fully self-driving cars need to safely navigate around all road users, from cars to pedestrians to cyclists. So, we’ve configured our radars so that they’re much more sensitive to these slower moving objects.
Hmmm, I see Waymo isn't claiming their radar system can detect stationary obstacles. So my guess is that they're just uisng Doppar radar, which only "sees" moving objects and not stationary ones. If Waymo's cars are is using an active sensor system to create a 3D map of the environment, they must be using lidar for that.
* * * * *
My armchair engineer conclusion is that fully self-driving, Level 4/5 autonomy, cars will need phased-array radar to create a SLAM system; that is, a 3D map of the environment around the car made, in real time, using active scanning. Phased-array radar is needed for seeing stationary obstacles; seeing only moving obstacles with Doppler radar quite clearly isn't sufficient. If it was sufficient, then cars using GM Super Cruise and Tesla Autopilot wouldn't keep running into stationary obstacles such as fire trucks parked in a highway lane.
And cameras aren't sufficient for reliably detecting obstacles, either. Neither moving nor stationary obstacles. According to one report I read recently, 50% of accidents happen at night, and 25% of them on unlit roads. We need fully autonomous cars to be able to operate just as safely on unlit roads at night as they do during the day, or on well-lit ones. Phased-array radar works just as well day and night, and doesn't need headlights lighting up the landscape to be able to "see" things. Phased-array radar also sees thru fog and smoke just fine, and does better than lidar or cameras at penetrating heavy rain or snow.
Nor is using cameras with headlights at night on unlit roads sufficient. It wouldn't be sufficient even if headlights were adequate, and according to the IIHS, most of them aren't. Lights pointed in the direction the car is driving won't help the car "see" vehicles approaching from other directions. Autonomous cars need to be able to prevent T-bone collisions and being hit from behind by cars without functioning headlights. Just preventing head-on collisions at night, on unlit roads, isn't sufficient for truly safe autonomous cars.
