hsu@eneevax.UUCP (Dave Hsu) (01/12/86)
In article <431@gcc-milo.ARPA> john@gcc-milo.UUCP (John Allred) writes: >In article <1006@ihlpa.UUCP> ibyf@ihlpa.UUCP (Scott) writes: >>Wait a minute, the air bag doesn't come out until you hit something, and if >>you don't want you "skills" and "reactions" obscurred by the bag, where >>were your "skills" and "reactions" to keep you out of the accident in the >>first place. Sorry guys, No validity in that argument. Try again! > >Come now, Sir Addison. Although my skills and reactions are good, they will >not keep me out of every possible accident. The other guy's action has much to >do with whether I can avoid him or not. > >The situation that I was thinking of, where I didn't want a bag in my face, >was this: after violently maneuvering to avoid an accident, I am faced with >a situation where I must hit something. So, I choose to hit the lesser of the >evils with a glancing blow. Presumably, I will still keep some forward motion, >and I will have to control the vehicle after the accident. The bag in my face >will significantly reduce my ability to control my vehicle. >-- >John Allred Ok folks, time to straighten a few things out. First, a few preliminaries. I DON'T believe that airbags should become mandatory for the same reason I don't believe we should force people turn the power off before playing with high voltages: those who are smart, will, and those who are stupid, become extinct. I do believe that airbags are effective, though, (and only when wearing a seat-belt) and that there should are no reasons that anyone has posed to me yet that I should even consider disabling them should they be installed in my car. Ok, on with the details. Firstly, contrary to the beliefs of a lot of you, your airbag will not go off if a malicious kid kicks your bumper, nor will it go off just as you see an accident developing. Nor will it go off if you slam your brakes, hit a pothole, drive over a speed bump, or if you slam your hood. Don't think that you're the first to consider these ideas, automakers have been trying to propose reasons for the last 15 years. As a result, most airbag systems employ 4 to 6 sensors (two in the very front of the car, two more in the dash, occasionally two more in the rear) and all of these systems require a combination of sensors to fire to weed out false alarms. Also, they won't pin you to your seats. Airbags are designed to inflate upon head-on impacts over 12 mph. The plastic bag touches only your chest, NOT your head or neck (from a proper seated position) and is arranged only to prevent you from being flung into your steering wheel. Observe that if you fail to wear your belts, the airbag WILL NOT prevent you from going through the windshield at substantial velocities as it is only anchored at the hub of your steering wheel. Along the same lines, they WON'T keep you stuck to your seat. In fact, airbags are designed to deflate within 45 milliseconds of inflation, which is to say, somewhat faster than most of you can react to the airbag's detonation. So by the time your brain has registered that the bag has been fired, it's already a collapsed piece of plastic. You'd much better be worried about the impact fractures you recieve if you lock your arms and legs than from any percieved injury you'll get from an airbag. Remember people: use your belts and your head, and you'd better have a better reason than the ones you've rehashed before you consider disabling your airbags. -dave "why-are-there-so-few-believers-in-airbags-who-may-someday-become- customers-for-my-friends-at-the-rescue-squad" hsu p.s. There are many sources of information on airbags, and almost all modern driver's education classes require students to view films concerning current safety equipment including airbags. Refer to the September '84 Discover magazine for a quick overview on page 8. And clean up those myths. -- David Hsu Communication & Signal Processing Lab, EE Department <disclaimer> University of Maryland, College Park, MD 20742 hsu@eneevax.umd.edu {seismo,allegra}!umcp-cs!eneevax!hsu CF522@UMDD.BITNET "Buckle up." "Hey, let's all be careful out there."
mat@mtx5a.UUCP (m.terribile) (01/14/86)
> >>Wait a minute, the air bag doesn't come out until you hit something, and if > >>you don't want you "skills" and "reactions" obscurred by the bag, where > >>were your "skills" and "reactions" to keep you out of the accident in the > >>first place. Sorry guys, No validity in that argument. Try again! > > ... > >The situation that I was thinking of, where I didn't want a bag in my face, > >was this: after violently maneuvering to avoid an accident, I am faced with > >a situation where I must hit something. So, I choose to hit the lesser of > >the evils with a glancing blow. Presumably, I will still keep some forward > >motion, and I will have to control the vehicle after the accident. The bag > >in my face will significantly reduce my ability to control my vehicle. ... > Firstly, contrary to the beliefs of a lot of you, your airbag will not go off > if a malicious kid kicks your bumper, nor will it go off just as you see an > accident developing. Nor will it go off if you slam your brakes, hit a > pothole, drive over a speed bump, or if you slam your hood. Don't think > that you're the first to consider these ideas, automakers have been trying > to propose reasons for the last 15 years. As a result, most airbag systems > employ 4 to 6 sensors (two in the very front of the car, two more in the > dash, occasionally two more in the rear) and all of these systems require > a combination of sensors to fire to weed out false alarms. > > Also, they won't pin you to your seats. Airbags are designed to inflate upon > head-on impacts over 12 mph. The plastic bag touches only your chest, NOT > your head or neck (from a proper seated position) and is arranged only to > prevent you from being flung into your steering wheel. Observe that if you > fail to wear your belts, the airbag WILL NOT prevent you from going through > the windshield at substantial velocities as it is only anchored at the > hub of your steering wheel. > > Along the same lines, they WON'T keep you stuck to your seat. In fact, > airbags are designed to deflate within 45 milliseconds of inflation, which > is to say, somewhat faster than most of you can react to the airbag's > detonation. So by the time your brain has registered that the bag has > been fired, it's already a collapsed piece of plastic. You'd much better > be worried about the impact fractures you recieve if you lock your arms > and legs than from any percieved injury you'll get from an airbag. > > Remember people: use your belts and your head, and you'd better have a > better reason than the ones you've rehashed before you consider disabling > your airbags. > > -dave "why-are-there-so-few-believers-in-airbags-who-may-someday-become- > customers-for-my-friends-at-the-rescue-squad" hsu > David: I believe that you are missing the point. Anything that can hold you back from impact in a 35 MPH collision by exploding in front of you can rip you away from the wheel -- or injure you if you are placed improperly. Also I DO want something to pin me in my seat ... that's the only way I can steer OR pump the brakes in a hard panic stop. As far as locking your arms, I don't expect to have time to ... and if I have the torso restraint I won't WANT to lock my arms. Without it, I am likely to, since I will be trying to control my body while braking like a sonovabitch. And airbag-equipped cars probably won't have the torso restraint, nor the necessary structural integrity in the posts to accept the restraint. Here's a realistic nightmare: About twice a year, the Garden State Parkway turns to invisible super-slick ice. You can't see it ... you can't brake on it ... all you can do is steer and ease off the gas -- slowly. Each time, it gets about 30 drivers or so, most non-fatal (car in ditch, driver quivering wildly). I am driving in the AM rush hour. I'm stuck in a pack between a bunch of drivers behind who want to do 75 (three lanes across) and a bunch who want to do 40 in front (3 lanes across). We've compromised on 50, with about 1/4 second of clearance between us. All of a sudden, the front drive in the center makes a sudden wheel adjustment, and his car fails to respond. He's on the ice. He hits his brakes and starts spinning. He hits the fellow to his right, then the one on his left. I ease off the gas and pray for an opening. The people on my left and right panic -- one goes into a straight skid, the other bounces off one of the reinforced wood guardrails. The fellow behind me hits me as I slow, and I pick up 8 MPH or so, then hit the fellow who just bounced off the guardrail. By this time I am spinning the wheel wildly and punching the gas in the hope of getting some traction and being able to not hit anyone else. My arm is across my body, and the impact with the fellow who careened off the rail sets off the airbag. The impact rips my hand from the wheel, injures my shoulder, elbow, and wrist. All of this takes place faster than I can comprehend. Now my car is out of control. I am stunned, with one disabled arm. The car crashes into an overpass support column (necessarily non-frangible) and I am without airbag and without torso restraint (which was not designed into the airbag-equipped car) so when the car hits, I slam into the wheel, which breaks a couple of ribs, one of which punctures my liver. Without prompt medical attention I WILL die from internal bleeding and resultant shock. All the staties and all the ambulances up and down the length of the parkway are up to their teeth in casualties. What are the odds of my getting that prompt medical attention? My front seat passenger, who slammed into the dashboard, suffered a fractured skull. He will live, but will not remember the accident. With the three-point harness, none of those injuries would have occurred. By the way, I DO favor the airbag for the passenger, but I want 3-point harnesses all around. Or 5-point harnesses. With the center buckle, they'd be easier to use. Oh, and the next time you feel embarrased about the belts, remember that no fighter pilot in the world would go up without his 4-or-5-point harness. And they don't make'em any tougher than that. That harness is NOT there for an accident. It's there because he can't safely operate the aircraft without it. And I feel the same way about the 3-point harness. -- from Mole End Mark Terribile (scrape .. dig ) mtx5b!mat (Please mail to mtx5b!mat, NOT mtx5a! mat, or to mtx5a!mtx5b!mat) ,.. .,, ,,, ..,***_*.
sykora@csd2.UUCP (Michael Sykora) (01/17/86)
>/* seifert@hammer.UUCP (Snoopy) / 6:44 pm Jan 10, 1986 */ >>> What about the >>>person whose eyglasses can't be made of safety glass? When the bag fires >>>and shatters the lens, it blinds him. The seat belt won't do that. >>Then THOSE people shouldn't use airbags. >Perhaps you could explain how one is supposed to avoid them when >riding in someone else's car, or a rental, etc. When riding in someone else's car -- take off the glasses. As far as rentals go, either don't rent or disconnect the airbag mechanism.
hsu@eneevax.UUCP (Dave Hsu) (01/20/86)
In article <1184@mtx5a.UUCP> mat@mtx5a.UUCP writes: >> [ I write ]... >> Also, they won't pin you to your seats. Airbags are designed to inflate upon >> head-on impacts over 12 mph. The plastic bag touches only your chest, NOT >> your head or neck (from a proper seated position) and is arranged only to >> prevent you from being flung into your steering wheel. Observe that if you >> fail to wear your belts, the airbag WILL NOT prevent you from going through >> the windshield at substantial velocities as it is only anchored at the >> hub of your steering wheel. >> >> Along the same lines, they WON'T keep you stuck to your seat. In fact, >> airbags are designed to deflate within 45 milliseconds of inflation, which >> is to say, somewhat faster than most of you can react to the airbag's >> detonation. So by the time your brain has registered that the bag has >> been fired, it's already a collapsed piece of plastic. You'd much better >> be worried about the impact fractures you recieve if you lock your arms >> and legs than from any percieved injury you'll get from an airbag. >> >> Remember people: use your belts and your head, and you'd better have a >> better reason than the ones you've rehashed before you consider disabling >> your airbags. >> >> -dave "why-are-there-so-few-believers-in-airbags-who-may-someday-become- >> customers-for-my-friends-at-the-rescue-squad" hsu > >David: > I believe that you are missing the point. Anything that can hold you >back from impact in a 35 MPH collision by exploding in front of you can rip >you away from the wheel -- or injure you if you are placed improperly. > >Also I DO want something to pin me in my seat ... that's the only way I can >steer OR pump the brakes in a hard panic stop. As far as locking your arms, >I don't expect to have time to ... and if I have the torso restraint I won't >WANT to lock my arms. Without it, I am likely to, since I will be trying to >control my body while braking like a sonovabitch. > >And airbag-equipped cars probably won't have the torso restraint, nor the >necessary structural integrity in the posts to accept the restraint. > >Here's a realistic nightmare: > > [ chaos on ice-slicked Garden State Parkway from driver ahead ] > >The fellow behind me hits me as I slow, and I pick up 8 MPH or so, then >hit the fellow who just bounced off the guardrail. By this time I am >spinning the wheel wildly and punching the gas in the hope of getting >some traction and being able to not hit anyone else. My arm is across >my body, and the impact with the fellow who careened off the rail sets >off the airbag. The impact rips my hand from the wheel, injures my >shoulder, elbow, and wrist. All of this takes place faster than I >can comprehend. > >Now my car is out of control. I am stunned, with one disabled arm. >The car crashes into an overpass support column (necessarily non-frangible) >and I am without airbag and without torso restraint (which was not designed >into the airbag-equipped car) so when the car hits, I slam into the wheel, >which breaks a couple of ribs, one of which punctures my liver. Without >prompt medical attention I WILL die from internal bleeding and resultant >shock. All the staties and all the ambulances up and down the length of >the parkway are up to their teeth in casualties. What are the odds of my >getting that prompt medical attention? My front seat passenger, who slammed >into the dashboard, suffered a fractured skull. He will live, but will not >remember the accident. > >With the three-point harness, none of those injuries would have >occurred. > >By the way, I DO favor the airbag for the passenger, but I want 3-point >harnesses all around. Or 5-point harnesses. With the center buckle, >they'd be easier to use. > >Oh, and the next time you feel embarrased about the belts, remember that >no fighter pilot in the world would go up without his 4-or-5-point >harness. And they don't make'em any tougher than that. That harness >is NOT there for an accident. It's there because he can't safely operate >the aircraft without it. And I feel the same way about the 3-point harness. >-- > > from Mole End Mark Terribile Sorry about including so much text, but I had to leave in the plug for harnesses. Well, Mark, there are a number of reasons your scenario is such a nightmare, and a number of reasons why it would not happen. Firstly, the airbag doesn't operate by pushing you away from the controls. Rather, the object is to inflate the bag before your head reaches the steering column, and to use the bag's deflation to slow yourself down. Imagine jumping into an inflated hot-air balloon, or onto a moon-bounce. This is the design principle behind airbags. The NHTSA conducted tests in the seventies to determine if airbags would make an average driver lose control in an accidental detonation. Test and control subjects were not told if an airbag would go off, nor when. Result: no loss from an ordinary operating position. Of course, if you're steering the car by holding on to the opposite side of the wheel relative to where your arm is, odds are good you won't hold on. But my guess is that you haven't been in a 12mph impact. Good, neither have I. But if you'd like some idea of what it's like, have some friends hoist you about 4 feet off the ground (in a driving-like position, of course) and drop you. In my book, that's good for 16fps minus a bit for air drag, which is somewhat under 12mph. Try to hold on to a steering wheel doing that. Now, imagine if there were a deflating bag between you and the floor. Get the picture? You're more likely to break your arm (shatter your glasses, etc) if it's across your body and you slam into a steering wheel, instead of an air bag. And don't tell me you're not wearing your harness: airbags aren't designed to be effective without them on anyway. You think the car won't be equipped with one? Unless somebody passes something to repeal it, the mandatory seatbelt law isn't just going to vanish, you know. No, I don't support mandatory airbags, and I've stated this many times over. But as added safety equipment in addition to three (or five) point harnesses, I'd rather have it than disable it. The only difference between an accident with an airbag and one without, is that I don't expect to smack anything into the steering wheel, and you, might. And don't tell me that an airbag is more dangerous that your wheel. Use your belts, -dave -- David Hsu Communication & Signal Processing Lab, EE Department <disclaimer> University of Maryland, College Park, MD 20742 hsu@eneevax.umd.edu {seismo,allegra}!umcp-cs!eneevax!hsu CF522@UMDD.BITNET "Vern Vern Vern Vern Vern Vern Vern, you've done it now, buddy..." -Ernest P. Worrell