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Musings on ASAS

3rd Gen LiDAR

May1, 2024 - Travis SImpkins (Owner ADAS On Call)

We hope we are not becoming the kind of people who don't get invited to parties because we won't shut up about some obscure bleeding-edge technology that we believe will change a fundamental aspect of human existence. Or, even worse, discover that we have been seated with the "crypto bro's" at a wedding.

But......we just have to tell you why we are so excited about the latest generation of LiDAR sensors and that because of them we could have fully autonomous vehicles before Boeing figures out how torque wrenches and doors work.

RADAR is RAdio Detection and Ranging. LiDAR is Light Detection and Ranging. It's faster and far more accurate than RADAR. No, we don't know why "LiDAR" gets the lowercase "i" and RADAR isn't RaDAR.

It's the "L" that's important here. Because it uses light, in the form of lasers, and RADAR uses Radio waves. LiDAR is clearly more awesome. Everybody has laser guns in the future according to every movie ever. No one is shooting radio guns, blasting k-pop songs at each other.

We are taking a few liberties with the science here (apologies to Bill Nye, and Neil Degrasse, and the actual applied science folks who, despite making pretty much everything possible, never get enough credit).

RADAR, in the most common ADAS functions today, beeps at you when you are backing out of the garage and it sees an object in the driveway. A backpack? Groceries? The neighbor 3 legged feral cat that has already been run over at least once? It "sees" objects, but that's about it. If you ignore the beeping, the AEB will grab a footful of brake and hand you a coffee-spilling hard stop.

It is good at blind spot monitoring, low speed collision avoidance or mitigation and has prevented tens of thousands of accidents. But the data from a RADAR signal is comparable to the data from a 3rd generation LiDAR sensor in the same way that a tetherball is comparable to an orbiting satellite.

RADAR might see something that could be a curbside trash bin- that is either on the road or possibly the sidewalk just around the corner ahead of you. It can't map the roadway very well around corners and is subject to interference from an array of environmental features. Like bushes.

3rd Generation LiDAR sensors are going to be the anchor of Level 3 vehicle autonomy (for now - just know that a car without a steering wheel or pedals is level 5, so three does some cool stuff).

They are currently in use or testing by Mercedes, GM, Volvo, and other OEM's. They are here - and fancy enough that lawsuits about patent infringement are dropping more often than Zach Bryan albums.

That thing ahead of you, just out of visual sight? LiDAR can identify it as a child (or a very small adult, or a Hobbit, possibly an Ewok but presumably a child).

48" tall with a larger-than-average body mass (kids really, really need more exercise these days). It is extremely accurate. With 3D mapping and a predictive database, LiDAR can identify that the kid has a pudding cup in one hand and is licking pudding off the screen of the phone held in his other hand. It is that good.

Note: Yes, eating pudding without a spoon is a gender-neutral activity, but odds wise that has 8-year-old boy all over it.

So he (or she) is 26" in the roadway, and by the time you are at the apex of the corner will have taken 1.65 additional steps placing him (or her) 38" from the centerline of your vehicle. Where the grill and headlight meet.

"Pudding Hands" is 35 yards ahead of you, although because of the Amazon van parked at the beginning of the kid's driveway on the inside of the corner, you won't see them for another 15 yards. This will occur in about 2/3 of a second.

It is reasonable to predict that this kid has zero spatial awareness. Unlikely to be any "athletic" moves in their repertoire. We hope Amazon is delivering something they might use in an outdoor activity, but more likely is just another case of gluten-free pudding cups).

At 50 mph you will cover the remaining 20 yards in 819 milliseconds.

Depending on the weight of your vehicle, road condition, and tire size and condition, the AEB (automatic emergency braking) might be able to bring you down from 50 in that 20 yards. Many collision avoidance systems can and will check for oncoming traffic and steer you around pudding hands while braking. A good system with 360 degree visibility will also check the speed and distance of the vehicle behind you, and mitigate the rear-end hit if the AEB has maximum braking applied.

But that won't be necessary in this case. Because of the LiDARs ability to map 3 dimensionally and include the roadway in the map, the AEB is already applying the brakes, bringing the speed down to 20 mph in the 15 yards before you are deep enough into the corner for line-of-sight visibility.

Now there is a whole universe of low-speed actions that you or the ADAS features can take. Probably won't even merit a horn honk, which could startle him (or her!) and is certain to cause panic and an additional loss of pudding.

So, yeah, we wholly recommend laying into the horn, at as close a range as possible.. A funny story to tell at home later.

Instead of the other thing.

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