Tesla footage of braking before crash ahead [video] • Hacker News Board

Re: Tesla footage of braking before crash ahead [video]

#161

Post by bcraven » Wed, Dec 28, 2016, 2:56 PM UTC

agumonkey wrote: post #152

brodie78382 wrote: post #140

Earlier quoted context omitted.

> The car behind didn't show turn signal Watch the video again; the little red car turns on their blinker and does a very slow shift to the right before clipping that stopped SUV. You're right that he wasn't paying attention, but his reaction time is incredibly slow - it looks like that car had just enough time to slam on their brakes or swerve to the right, yet they did neither.

It's odd that the turn signal is only located at the top of the car. I guess the mid height one was broken ? I think the situation is not entirely unclear, it seemed that there was a problem ahead of the SUV, that made a bunch of cars slow down altogether. I still don't understand the smaller red car driver decisions.. maybe he didn't know what to do and hesitated and tried to swerve as a last resort. Or maybe he was…

It looks like a 2001 Vauxhall Corsa, that is just where the indicators are.

Re: Tesla footage of braking before crash ahead [video]

#162

Post by rdslw » Wed, Dec 28, 2016, 3:11 PM UTC

gingerlime wrote: post #105

sytelus wrote: post #67

This is great video to study on many levels beyond self-driving car. Some observations: * The car behind didn't show turn signal so probably driver wasn't paying attention. * A small car escaping with not too much damage while SUV rolls over many times * From physics point of view, the car behind produced almost perfect torque that started horizontal spin on SUV * Collisions with barrier at high speed can produce lot…

I'm feeling rather dumb, but can't really intuitively understand the physics here. I see a small car hitting a pretty huge one and yet spins the huge one several times. I always thought those bigger cars are safer / stronger / more resistant to hits? Is it purely because it hit it at the corner, so all the force went into the "spinning axis"? (did I say I feel dumb?)

Look on two things:

A) main that SUV happened (just before starting sommersaults) to position itself orthogonal to its previous way of moving. In this position all wheels of SUV created massive 'resistance' to continue move forward

B) it happened partialy because of the middle barrier. WOuld it be missing, SUV would probably move (on the arc) without sommersaults.

Change of orientation was caused by small car, but look that up to moment A) SUV more less was moving fine.

Re: Tesla footage of braking before crash ahead [video]

#163

Post by empath75 » Wed, Dec 28, 2016, 3:14 PM UTC

Rapzid wrote: post #16

ChuckMcM wrote: post #2

I thought this an interesting video when Elon retweeted it. Basically the car is responding faster than the people do and keeping things from escalating. That said, having been on 101 when the cars in front start dancing like that I have to say my biggest worry isn't stopping in time its having someone behind me not stop.

That's why I usually break fast initially and check the rearview; extend the braking distance to allow extra room for the person behind if they are too close.

When I'm driving, I'm usually always thinking about having escape paths. I get nervous if I don't have a shoulder or a clear lane next to me, unless traffic slowed to a near stop.

Re: Tesla footage of braking before crash ahead [video]

#164

Post by zo1 » Wed, Dec 28, 2016, 3:16 PM UTC

gingerlime wrote: post #105

sytelus wrote: post #67

This is great video to study on many levels beyond self-driving car. Some observations: * The car behind didn't show turn signal so probably driver wasn't paying attention. * A small car escaping with not too much damage while SUV rolls over many times * From physics point of view, the car behind produced almost perfect torque that started horizontal spin on SUV * Collisions with barrier at high speed can produce lot…

I'm feeling rather dumb, but can't really intuitively understand the physics here. I see a small car hitting a pretty huge one and yet spins the huge one several times. I always thought those bigger cars are safer / stronger / more resistant to hits? Is it purely because it hit it at the corner, so all the force went into the "spinning axis"? (did I say I feel dumb?)

The SUV had forward momentum, yet it was suddenly facing sideways due to the side-back impact from the smaller vehicle. That means the tires were skidding and "gripping" the car at the base rather than "rolling", while the whole body wanted to go forward. Hence, it toppled and kept rolling because there was nothing to stop it.

Re: Tesla footage of braking before crash ahead [video]

#165

Post by williamle8300 » Wed, Dec 28, 2016, 3:18 PM UTC

The underlying software for this mainly plugs into the Instagram servers. When it detects unusually high activity in proximity to the car, like commenting, liking, and especially video posts, it makes a cautionary beeping sound.

/s

Re: Tesla footage of braking before crash ahead [video]

#166

Post by agumonkey » Wed, Dec 28, 2016, 3:18 PM UTC

bcraven wrote: post #161

agumonkey wrote: post #152

Earlier quoted context omitted.

It's odd that the turn signal is only located at the top of the car. I guess the mid height one was broken ? I think the situation is not entirely unclear, it seemed that there was a problem ahead of the SUV, that made a bunch of cars slow down altogether. I still don't understand the smaller red car driver decisions.. maybe he didn't know what to do and hesitated and tried to swerve as a last resort. Or maybe he was…

It looks like a 2001 Vauxhall Corsa, that is just where the indicators are.

Shit that's bad, it's really not very large and "originally" placed.

Re: Tesla footage of braking before crash ahead [video]

#167

Post by Rainymood » Wed, Dec 28, 2016, 3:20 PM UTC

They are speaking Dutch so I thought i'd translate what they are saying:

Man: Wacht even wacht even eerst kijken wat er achter ons gebeurt (Wait, wait, first take a look what is happening behind us, don't get out yet.)

Man: Blijf zitten blijf zitten. (Stay seated, stay seated.)

Woman: Niets doen niets doen niet eruit gaan alsjeblieft. (Don't do anything, don't do anything, don't get out of the car yet please.)

Man: Nu kunnen we kijken wat er aan de hand is. (Now we can check out what happened.)

Woman: Maar zet hem eerst even aan de kant. (But first put it [the car] on the side of the road.)

We now see the man running to the car in a blue shirt on the left side of the screen.

Woman to the kids: Jongens jullie moeten even in de auto blijven zitten. (Guys, you have to stay in the car for a little while.)

Kids: Ja. We willen er ook niet uit. Moet jij ook blijven zitten? (Ok. We don't wanna go out. Do you [mom] have to go out as well?)

Woman: Ja ik moet er uit, ik ben een arts. (Yes I have to go, I'm a doctor).

Re: Tesla footage of braking before crash ahead [video]

#168

Post by Rainymood » Wed, Dec 28, 2016, 3:20 PM UTC

bengale wrote: post #130

pipio21 wrote: post #124

One of the main causes of accidents are vehicles left on the road and other vehicles impacting them or the people as they take for granted that traffic will be fluid and are distracted or whatever. You should never leave your children and family on a car on the left lane while you leave, never. I have a neighbor that is paraplegic because of that. His entire family went to the hospital after a vehicle crashed from be…

In fairness the guy is saying that in the video. Stop, wait to see what the cars do behind, etc. Presumably he gets out when traffic has stopped behind him.

They are speaking Dutch so I thought i'd translate what they are saying:

Man: Wacht even wacht even eerst kijken wat er achter ons gebeurt (Wait, wait, first take a look what is happening behind us, don't get out yet.)

Man: Blijf zitten blijf zitten. (Stay seated, stay seated.)

Woman: Niets doen niets doen niet eruit gaan alsjeblieft. (Don't do anything, don't do anything, don't get out of the car yet please.)

Man: Nu kunnen we kijken wat er aan de hand is. (Now we can check out what happened.)

Woman: Maar zet hem eerst even aan de kant. (But first put it [the car] on the side of the road.)

We now see the man running to the car in a blue shirt on the left side of the screen.

Woman to the kids: Jongens jullie moeten even in de auto blijven zitten. (Guys, you have to stay in the car for a little while.)

Kids: Ja. We willen er ook niet uit. Moet jij ook blijven zitten? (Ok. We don't wanna go out. Do you [mom] have to go out as well?)

Woman: Ja ik moet er uit, ik ben een arts. (Yes I have to go, I'm a doctor).

Re: Tesla footage of braking before crash ahead [video]

#169

Post by matheweis » Wed, Dec 28, 2016, 3:24 PM UTC

skc wrote: post #78

pmontra wrote: post #73

Earlier quoted context omitted.

SUVs are not as stable as cars with a lower height. Think about the typical race car which is designed for turning fast, something that requires stability: light, low and wide. SUVs? Heavy, high and narrow relative to their height. Electronics can do marvels, but with the same electronics physics wins. I remember I could easily outperform a couple of BMW SUVs on a highway in a descent from a mountain pass. They had p…

I'm really curious to know exactly where you can legally drive downhill at > 100 km/h

In the US, especially out west, 75-80mph (~130km/h) is commonly set as the legal speed on most of the freeways.

Re: Tesla footage of braking before crash ahead [video]

#170

Post by 79d697i6fdif » Wed, Dec 28, 2016, 3:25 PM UTC

sytelus wrote: post #67

This is great video to study on many levels beyond self-driving car. Some observations: * The car behind didn't show turn signal so probably driver wasn't paying attention. * A small car escaping with not too much damage while SUV rolls over many times * From physics point of view, the car behind produced almost perfect torque that started horizontal spin on SUV * Collisions with barrier at high speed can produce lot…

The biggest thing I noticed was just how easily SUV's flip over. This has been a problem forever I'm just surprised that regulators don't take more notice of it. Rollovers are far more likely to result in injury or death.

Most cars just don't flip, all the traction their tires have is simply not enough to do it on flat ground. Yeah anything could flip over once you go off the road but the SUV in this looks like a rolling death machine.