Like I said, there are a lot of "smart switches" in the canbus system
- but although they may use"microprocessors" they are not computers. The microprocessor is used as a switch. Switches are binary digital devices too - canbus switches are solid state and remote control. They do NO data processing so are not REALLY computers.
That said, even if you count them, and use a Bimmer as your example (likely the most over-computerized space-ships in tha galaxy) finding
100 microprocessor controlled devices, muchless microprocessors, would be a big stretch.
And counting the display driver on an LCD display as a "computer" is a real stretch of litterary licence!!!!!
You are so smart and argumentative, why don't you provide even ONE proof that ANY car has that capability built in??? I've given you ONE from the late fifties, that is documented to have the possibility of being unable to be shifted into neutral, and ONE from the early fifties that DEFINITELY, BY DESIGN, was IMPOSSIBLE to shift into neutral at speed .
The first was the Edsel Telletronic - and the second was the Packard UltraMatic. Both were totally out of the picture by the early 1960s.
Properly applied, the brakes are adequate. Pumped or tentatively applied they are not. The brakes can not be depended on to CONTROL the speed. They must be used to STOP THE CAR. As quickly as possible.
On a spark ignition, port injected, gasoline engine the fuel must be SHUT OFF to prevent runnaway if the air throttle is held open.. The fuel can be INTERMITTENTLY shut off, but cannot be "flow reduced".
I'll explain why. With the throttle open, a more or less constant volume of air per cyl stroke is pumped into the engine. A very narrow range of mixtures will reliably fire in that cyl under the pressure of combustion. Any leaner than that "lean limit" will not ignite in the cyl. Instead it will be pumped out directly into the extremely hot and reactive catalytic converter - where it WILL burn - flashing th converter white hot, damaging it in a "flash" and very likely causing a fire by overheating any flamable materials within 6 inches, whether protected by a steel floorpan or not.
I've seen floormats and consoles burned out of cars from this exact problem in the past.
By SHUTTING OFF fuel flow, you either have proper combustion mixture or you have air. No catalytic converter issues. No overheating issues. No emission control issues. No safety issues.
My Buick can be shifted into any gear you wish at speeds over 45 mph. Of course, nothing will happen. Shift to Neutral, you're still in Drive, shift to Reverse, still nothing happens and you stay in drive. I know because when I read it in the manual, I tried it. All but Park, that is; I took their word for it on that one. A step further, if you stick it in L1 and floor it, you'll still go shifting through three of the four gears. Only overdrive won't kick in since it takes an electrical switch to do that, which is held open unless you're in drive. Anyone who can't turn off the key when they finally realize what's going on though would have to be quite a rube.
What Buick is that? When I shift mine into neutral, it is in neutral, not drive. 2001 LeSabre and 1991 Regal went out of gear. I did not try reverse. .
Already done as to a cite for it being proved and as I said I have no cite from Toyota. You _could_ try reading my respons to you directly above this but that might be asking just a bit too much of you.
In at least one case it was a Lexus and I think it was in both. If you want to look it up, got ahead. According to you it is simple and you seem to be expert on simple.
Keep trying and digging yourself deeper. Anyone who claims that they did _not_ see those news reports OR the cites to them in this thread has no credibilityi.
| It's not up to me to watch the news to prove your claims. You | claimed specifically that a Lexus had been brought to a stop by | shifting into neutral during runaway conditions. First, on the face | of it, this is actually impossible to do, because no one has been able | to duplicate the "runaway" condition. So, the best you could be | referring to was that it's been proven that a Lexus identical to the | one driven by the CA highway patrol officer can be shifted into | neutral when traveling 120mph under full throttle.
I'm sorry if this is a stupid question, but I really don't know: typically, does shifting an automatic transmission into neutral actually disengage a gear or does it merely cause the torque converter to stop transferring torque?
Let me explain why I ask. I have a 1997 Toyota Landcruiser with automatic transmission. It also has a (totally mechanical) shift on the transfer case to select low or (normal) high speed. The manual says to put the automatic transmission in neutral when you want to change the transfer ratio. If I follow those instructions I hear/feel a nasty gear grinding when I try to shift the transfer case, suggesting that somehow the output of the transmission is still rotating with at least some force. If I put the automatic transmission in park then transfer case shifting is smooth and quiet, though as I pass through the neutral position of the transfer case I get a warning light that the A/T parking break is no longer effective. The manual says not to do this, but I'm not sure why.
Incidentally, there are two solenoid interlocks that can prevent certain shifts of the automatic transmission but nothing (well, at least nothing electric) that can stop me from putting the transfer case in neutral so I figure I'm safe no matter what any computer may decide to do. :)
Yeah, I think everyone wants to know the answer to that question. It's amazing how when some people are dead wrong on something, instead of just saying "you're right", they prefer to really make an ass of themselves.
Using even a trivial example, where a microprocessor is used as a switch, then it:
has a CPU has memory executes a program has input and output
That's the basic definition of a computer. How about I write a simple assembly language program that implements a switch function, turning a keyboard light on and off, put it in a flash memory chip, and replace the bios on my PC with it? The light is now flashing. Is my PC no longer a computer just because it's running a very simple program?
Who should we believe, you or a website dedicated to embedded control? Let's say they are off by 2X. That's still a long way from your claim that there are only one or two computers in any car. I'm still waiting for a source on that.
It's no stretch at all if the display is in fact implemented by using a microprocessor or microcontroller. If it's implemented strictly via a digital hardware device, ie, it isn't a cpu running a program, then yes it would be just a display driver. I think the embedded system development folks know the difference. Some key point are that it makes sense to use a computer as opposed to just digital logic because it's cheap, easy to design, re-programmable during developemt, manufacturing or potentially in the field without changing the hardware and once you have it in the display, you can then add all kinds of nifty features because the cpu is already there and can handle more stuff for free. If you read the article I provided, they even point to the first use of a Motorolla 6802 microprocessor in the 1978 cadillac dashboard display to implement the trip computer.
I guess that means you have no link. Kind of strange since you accused me of not watching the news, because the test case proof you are crowing about was all over the news. Why it was everywhere. Yet, you have not a single link and you think I should just take what you say you saw on TV as all there is too it. Here's an example of where that will get you. I watched the 60 Minutes segment on Bloom Energy. I come in here and say "60 Minutes last night had a story about a company that is going to soon have everyone generating their own electricity at home using a cube that is about 6" on a side". Following your rules, that's all there is to it and anyone who dares ask for a link to more info about it is being unreasonable. Why it's been all over the news. I saw it on TV! Just for the record, I can provide you with many links to the Bloom Energy story.
In article , snipped-for-privacy@milmac.com (Doug Miller) writes: | In article , ddl@danlan.*com (Dan Lanciani) wrote: | | | >I'm sorry if this is a stupid question, but I really don't know: | >typically, does shifting an automatic transmission into neutral | >actually disengage a gear or does it merely cause the torque | >converter to stop transferring torque? | | Neither, actually. It disengages a clutch inside the transmission.
Interesting. Is disengaging that clutch used for anything else (except perhaps park)? If that clutch on my vehicle were not fully disengaging would I likely observe any other symptoms or would the torque converter absorb the rotation in park and at idle in neutral with the transmission loaded (i.e., with the transfer case not in neutral)?
A typical automatic transmission has several internal clutches that are engaged, or disengaged, by hydraulic pressure. The gearing in an AT consists of multiple sets of planetary gears, and the clutches lock or release various parts of the various gearsets to control the gear ratios. The clutches are disengaged in both neutral and park. In park, additionally, the transmission output shaft is mechanically locked by a pin or bar which prevents it from turning.
I would expect harsh shifts and unpleasant noises.
Given that the torque converter can absorb the engine's rotation with the transmission in gear and the vehicle stopped with the brakes applied... I'd have to say yes. :-)
I'd draw the line between hardware implementation of a function and a "computer" whether or not it has a _stored_program_. How that stored program is accessible is up for discussion. ;-)
The computer is not the switch, in this usage anyway. It may control a switch, but it is not in itself one.
There is a murky area here, which you even alluded to. Is an FPGA a computer? (no need to answer that ;)
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