5 ms·

Depends on what kind of crash it is. My dumb guess is that most crashes can be predicted by sensors in advance of the moment of impact, perhaps by significant

by dsjoerg 10y ago

Depends on what kind of crash it is. My dumb guess is that most crashes can be predicted by sensors in advance of the moment of impact, perhaps by significant multiples of 150ms. For example consider a crash where your car slips on ice and drives right into a tree. Before you hit the tree there's gonna be all kinds of crazy steering and braking attempts that sensors could detect, and the accelerometers are gonna show weird lateral ice-slipping motions.

digler999 10y ago
> most crashes can be predicted by sensors in advance of the moment of impact, Provided you dont have any false alarms. For instance, someone making an unsafe pass on a 2-lane road, lets say a fast motorcycle. radar sensor sees incoming object with relative velocity of 150mph, see's driver slam brakes, yet motorcycle dives back into his lane at the last second. In this case, deploying the airbag without accelerometer input would actively harm the driver.
- kpil 10y ago
  Once when I was on a walk, a car activated all airbags just before it passed me while being driven in the opposite direction. I was more or less looking at it all the time, so there was no external factors - just a very loud thud. The speed was perhaps 25 km/h which was good, because the young lady in the car just kept driving straight ahead - no braking or steering or anything - until the car slowly hit the kerb and then a sign post 75 meters down the road and came to a stop. There was no external damage to the car - or perhaps the fender was slightly dinged. I walked there, while figuring out what had really happened and noticed that the driver was just sitting there in the car while it started to be filled with white smoke. When I got there the car was more or less full of smoke, and the young lady still in the drivers seat looking straight ahead and appeared to be very confused. Someone else got there a few seconds before me and opened the doors to the now totally smoke filled car, and the lady sort of woke up - and she got out just as I got there. I think she was physically fine - no arms broken although that could happen when an airbag deploys - but she was really confused although she was starting to get a grip after a minute or so, and started to worry about the blown up interior in her car... I guess it's one of those things you really don't know how you will react - she totally froze. If that would have happened at any sort of speed, I'm pretty sure it could been a fatal accident.
  - komali2 10y ago
    Why did the car activate the airbags? What car is this? I've never heard of airbags deploying improperly before (except when we have a busted set that we use to launch a tire a million feet into the air).
    - kpil 10y ago
      I don't remember what car it was, it was somewhere between 7-10 years ago. Possibly a small Toyota, or another asian car. I remember that I had to look it up at the time - and apparently a spontaneous deployment is not unheard of, but rather uncommon. Old news article: http://www.autonews.com/article/19980824/ANA/808240708/airbags-trigger-new-fears-as-no-cause-deployments-rise-safety-experts-seek-answers http://www.autonews.com/article/19980824/ANA/808240708/airba...
  - digler999 10y ago
    > I guess it's one of those things you really don't know how you will react In my case of the hypothetical close-call, I think if I had a car with one of these "impending doom" tones, just hearing that tone in conjunction with a near-miss on the road would probably give me a heart attack.

by dsjoerg 10y ago

digler999 10y ago

> most crashes can be predicted by sensors in advance of the moment of impact, Provided you dont have any false alarms. For instance, someone making an unsafe pass on a 2-lane road, lets say a fast motorcycle. radar sensor sees incoming object with relative velocity of 150mph, see's driver slam brakes, yet motorcycle dives back into his lane at the last second. In this case, deploying the airbag without accelerometer input would actively harm the driver.

kpil 10y ago
Once when I was on a walk, a car activated all airbags just before it passed me while being driven in the opposite direction. I was more or less looking at it all the time, so there was no external factors - just a very loud thud. The speed was perhaps 25 km/h which was good, because the young lady in the car just kept driving straight ahead - no braking or steering or anything - until the car slowly hit the kerb and then a sign post 75 meters down the road and came to a stop. There was no external damage to the car - or perhaps the fender was slightly dinged. I walked there, while figuring out what had really happened and noticed that the driver was just sitting there in the car while it started to be filled with white smoke. When I got there the car was more or less full of smoke, and the young lady still in the drivers seat looking straight ahead and appeared to be very confused. Someone else got there a few seconds before me and opened the doors to the now totally smoke filled car, and the lady sort of woke up - and she got out just as I got there. I think she was physically fine - no arms broken although that could happen when an airbag deploys - but she was really confused although she was starting to get a grip after a minute or so, and started to worry about the blown up interior in her car... I guess it's one of those things you really don't know how you will react - she totally froze. If that would have happened at any sort of speed, I'm pretty sure it could been a fatal accident.
- komali2 10y ago
  Why did the car activate the airbags? What car is this? I've never heard of airbags deploying improperly before (except when we have a busted set that we use to launch a tire a million feet into the air).
  - kpil 10y ago
    I don't remember what car it was, it was somewhere between 7-10 years ago. Possibly a small Toyota, or another asian car. I remember that I had to look it up at the time - and apparently a spontaneous deployment is not unheard of, but rather uncommon. Old news article: http://www.autonews.com/article/19980824/ANA/808240708/airbags-trigger-new-fears-as-no-cause-deployments-rise-safety-experts-seek-answers http://www.autonews.com/article/19980824/ANA/808240708/airba...
- digler999 10y ago
  > I guess it's one of those things you really don't know how you will react In my case of the hypothetical close-call, I think if I had a car with one of these "impending doom" tones, just hearing that tone in conjunction with a near-miss on the road would probably give me a heart attack.