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Google Patents Self-Driving Car That Glues Pedestrians To The Hood In A Crash (cnn.com)
An anonymous reader quotes a report from CNN: Google just got a patent for a special kind of coating on self-driving cars that could help prevent pedestrian injuries. The company wants to coat autonomous vehicles with a sticky substance so that if they hit a pedestrian, the person would be glued to the car instead of flying off. "[The pedestrian] is not thrown from the vehicle, thereby preventing a secondary impact between the pedestrian and the road surface or other object," says the patent, granted on Tuesday. Google explains that an "adhesive layer" would be placed on the hood, front bumper and front side panels of a car. A thin coating would protect it until an impact occurred. Google is paying Arizona residents $20 per hour to test its self-driving vehicles.
between the car and another object/vehicle
Twinstiq, game news
They're not always good.
It will only stick pedestrians. Not dirt, birds, cats, etc ;-)
There's bugs in their idea. Literal bugs. They're already a pain in the ass to scrape off a vehicle. This conceivably makes the problem worse. I suppose if you live in the valley the homeless are thicker than he insects, but this is worthless outside of the bubble. . . . err valley.
A thin coating would protect it until an impact occurred.
Okay, so the concept is the person is hit by the car and does not go flying 20 feet when the car hits them. They have an outer-shell that is reasonably strong so you're not picking up bugs, grass, etc. Sounds like a plan.
My question is "How do you get the person unstuck afterwards?"
So I'm standing in the road and the car hits me, I stick to his hood and I'm now traveling the speed of his car, let's say 30 MPH. He jams on his brakes because, let's face it, there's a guy stuck to his hood. The nice thing is that I'm not going to fly off the car at 30 MPH. The car comes to a stop and the driver gets out and asks if I'm okay. I may have some bumps and bruises, but I'm good.
Okay, that's gotta be pretty good stickum to hold my 180-pounds to the car while it's decelerating. So how do I peel myself off the hood of his car? I mean, I would imagine that any stickum that can hold me in place while a car decelerates from 30 to 0 is not going to let me just get up afterwards.
And Lord help the hairy shirtless men who get hit. That's gonna hurt!
A very quick skim of the patent says that there would be a coating on top of the adhesive coating. This top coat is designed to break during impact, exposing the pedestrian to the adhesive underneath.
I'm not sure the patent designer considered what to do when the car is inevitably hit with gravel or other objects that are sharp or have enough energy to break the topcoat.
I suspect the logic for this idea comes from considering an elastic collision between a heavy and light object.
for a car with mass M, and intial velocity Vi and pedestrian of mass m, with initially no velocity and then final velocity Vp we can write:
MVi = MVf + mVp
MVi^2 = MVf^2 + mVp^2
for conservation of momentum and energy.
Solving these equations for Vp we get
Vp = 2 Vf *M/(M+m) ~ 2Vf
so an elastic collision throws the pedestrian off at a speed of twice the car's velocity, who then hits the ground.
If the pedestrian sticks to the car their final velocity if half that and four times less energtic.
Even if it's not a fully elastic collision the point is taken it's better to stick to the car.
Some drink at the fountain of knowledge. Others just gargle.
It can’t JUST be a sticky layer, otherwise it’ll last about 5 minutes before it gets a layer of environmental debris on it.
And another 5 minutes until the miscreants realize how much fun it is to stick crap on people's cars while they're sleeping.
I live in Wisconsin. On the back roads, it's not uncommon to see deer attempt to cross traffic, and there are quite a few unlucky motorists who manage to hit one.
Now, if the impact doesn't kill the deer, I have an angry/terrified deer thrashing about on my hood.
If the impact *does* kill the deer, I'll need to have tags with me, since I'm now transporting a deer that I just killed.
Take it to the limit, everybody to the limit, come on, everybody fhqwhgads.