Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site eneevax.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!umcp-cs!eneevax!hsu From: hsu@eneevax.UUCP (Dave Hsu) Newsgroups: net.auto Subject: Re: airbags *LONG RESPONSE* Message-ID: <474@eneevax.UUCP> Date: Mon, 6-Jan-86 14:01:09 EST Article-I.D.: eneevax.474 Posted: Mon Jan 6 14:01:09 1986 Date-Received: Tue, 7-Jan-86 07:11:24 EST References: <493@imsvax.UUCP> Reply-To: hsu@eneevax.UUCP (Dave Hsu) Organization: Imperial Widget Research Center, Kingdom of Maryland Lines: 74 Summary: the myths some of you still propagate In article <493@imsvax.UUCP> ted@imsvax.UUCP (Ted Holden) writes: > Since air bags may someday be standard items on many if not all of >the cars being sold in America, there are several questions which >potential owners of such vehicles should consider. These include: > >1. Since these devices will in all likelihood be microprocessor >controlled, and the cars owned longer than 3 years average, the first >question is "How many microcomputers have I ever seen go three years and >never break or need repairs?". Of course, when a PC breaks, you simply >send it out for repairs, no big deal; a problem with the microprocessor >controlling your airbag would, of course, be a whole lot worse than >that. >2. Your PC doesn't sit out in the cold and get rained on like your car >does; is there any reason for thinking it would break LESS often if it >did? > Absolutely. The PC fails because (among other reasons) it has an astronomical parts count for what it performs. I used to work for a computer store, and virtually the ONLY machine (besides the Commodore 64) which came in for service was the IBM. Never saw a Xerox, Compaq, or Wang ever come in. If car computers fail as often as you think they do, then all of us Ford EEC/IV equipped people will have something much more important than an airbag to worry about....how well does YOUR car operate when the engine controls short out? Don't look so smug, all you anti-lock equipped people. And you Chrysler and Saab turbo boost control people too. And all of you who have EFI. In fact, how many of you with new cars DON'T have EFI? >3. In view of the first two questions, and noting that the average American >driver isn't terribly good even WITHOUT being pinned into his seat and >blinded, is there any particular reason to to think he would function >better or even as well when he was? > I don't know if they ever showed you films of operating airbags, but a) they don't pin you to your seat. It's only a thin balloon which deflates almost instantly. b) the propellant is smokeless. Among the first things the NHTSA did was to address the complaints of those who felt that airbags take control away from the driver, by running blind studies on random subjects. The drivers were not told if their vehicles' air bags would inflate, nor when. And it showed conclusively that even random detonations did not cause the test drivers to lose control. Don't think you beat Detroit to complaining about `loss of control'. They've been whining for years. >4. Aside from accidental problems such as these, is there any reason to >think that a particularly large, strong, and evil-minded ten-year-old >(such as I was 30 years ago) couldn't simply run up to cars stopped at a >light and kick their bumpers, and laugh gleefully at the poor idiots >trapped inside? > Yes, there is a reason. Again, people have worried before about these things. Airbags cannot be detonated by kicking a bumper. In virtually all airbag systems today, at least two or three accelerometers must go off before the system will fire. I'll look in the Benz manual to find out how many sensors their SRS uses, if you're interested. And again: the bags will not trap you. >5. I could think of a lot more such questions. The only one that >really counts is "How do we stop this kind of crap?". Or, failing that, >how do we disable the things? I still don't understand why you people are so vehemently opposed to airbags. Maybe they didn't show you films about them back when you took Driver's Ed. But then again, I still don't understand why some other people are opposed to seatbelts. If nothing else, sooner or later natural selection will take its course. Today, I'm comfortable enough about airbag technology to not want to disable one in my car. Some day, there may be that S-curve that I don't make. And when I don't, I want as much in front of me as possible. -dave -- David Hsu Communication & Signal Processing Lab, EE Department University of Maryland, College Park, MD 20742 hsu@eneevax.umd.edu {seismo,allegra}!umcp-cs!eneevax!hsu CF522@UMDD.BITNET And then there were none.