From: dizzy on
clare(a)snyder.on.ca wrote:

>Oh, it detects the lockup all right - and RELEASES all 4 wheels to get
>them turning again. Result? No brakes. They come back on again as soon
>as the wheels start turning - locking all 4 again

You guys need better tires, and stop blaming ABS if you can't stop on
glare ice - you wouldn't be able to, anyway.

From: dizzy on
clare(a)snyder.on.ca wrote:

> In wet sloppy snow with wide tires, ABS is TERRIBLE.

Nonsense.

From: clare on
On Thu, 11 Mar 2010 18:35:29 -0500, Bill Putney <bptn(a)kinez.net>
wrote:

>clare(a)snyder.on.ca wrote:
>
>> ...Properly designed and implemented
>> electronic controls are more reliable than properly designed and built
>> mechanical systems. Ther is NO WEAR, and NO MOVING PARTS. Moving parts
>> either wear or seize or break in time.
>> If electronic devices are operated within their design voltage and
>> temperature parameters they can last virtually forever. 10s of
>> thousands of operating hours at the minimum.
>
>You forget one thing: Modern (automotive) electronics are made using
>surface mount components, and surface mount solder bonds (as currently
>done in the modern automotive world) are particularly bad at
>withstanding years of thermal cycling and other environmental exposure.
> All these electronic module failures (hard and intermittent) are
>probably 90+% due to the failure of surface mount component-to-board
>bonds. A chain is only as strong as its weakest link - and that is it.
>

You forget the main culprit - LEAD FREE SOLDER.


>You might argue "Well, then they aren't properly designed and
>implemented, are they?". That may be true, but it is a fact that you
>can't get away from in the present state of automotive electronic
>manufacturing.
>
>I claim that the admission has to be one of two things:
>(1) Surface mount electronics as currently utilized in the present
>automotive industry do not fit into the category of "proper design and
>implementation", or
>(2) Even properly designed and implemented electronics (by modern
>standards of the automotive industry) are prone to failure.
>
>Perhaps you would choose (1)? Or do you not accept that electronic
>modules in our automobiles have real failure rates over the life of the
>vehicle?
>
>You might have one valid counter to this if you were to say that a
>proper design would be fail safe (for the uninitiated, that means that
>things may fail, but when they do, they do so in a safe manner). But
>then, can we anticipate all failure modes and analyze their results? (I
>have served on FMEA teams for major manufacturers, so I know what I'm
>talking about in this area.) It probably is a circular argument,
>because you could always claim that "...then it is not properly designed
>and implemented, is it?", and I couldn't disagree with you.

Bean counters. And greenies. Lead free solder and bean counters on the
same project can definitely cause problems.

But bean counters and engineers on the same project ALWAYS cause
problems - whether mechanical or electronic - which IS why I qualified
both conditions - electronic and mechanical - as properly designed and
implemented.

You caught that.
>
>Perhaps this relates back to some of the Toyota problems, perhaps not.
>But electronics do fail - you have to decide if that is due to (1) or
>(2) above.
ANd all told, Toyota has had a lot less of those problems, up 'till
now, over the long haul, than virtually ANY American manufacturer.
Toyota electronics over the years have been WAY above average.
NipponDenso components in particular.
From: Dillon Pyron on
Thus spake Bill Putney <bptn(a)kinez.net> :

>jim beam wrote:
>> if you buy all this fear-mongering idiocy that electronic throttle is a
>> problem, and that brakes, transmissions and ignition kill switches can
>> all simultaneously fail causing a driver to lose control, it might be
>> worth auto manufacturers of all stripes to adopt a slightly different
>> implementation of electronic throttle [e.t.] - if not for mechanical
>> reasons, but to shut the idiots up...
>
>The lawyers, politicians, and news media can convince the public of the
>impossible (failure even a totally fail safe system) any time they
>decide to do it depending on political or monetary motivation. IOW -
>the people and companies who do a good job of designing are going to get
>punished anyway (unless they know how to play the game in a corrupt
>system). There are people in our society whose life goal is to make
>sure that that happens.

The people who are pushing this issue have no idea about complex
software systems. You can not test for all of the potential
combinations of events.

Backing off on the throtle while getting airborn at the crest of a
hill with the brakes gently applied and the A/C on? I can come up
with hundreds and hundreds more. And everyone her can probbly match
those numbers without a repeat.

The EE who hacked a failure is an academic, not a real world person.
You have to apply the 20-80 rule. 20% of the problems will generte
80% of the failures. You are more likely to grind a brake pad to
metal than to have the concotted failure he caused. Much more.
--

- dillon I am not invalid

You know, I can't think of nothing finer than a fine
naked woman holding a gun. And you got all kinds of
fine going on.

Frankie Figs
From: clare on
On Thu, 11 Mar 2010 19:06:20 -0600, dizzy <dizzy(a)nospam.invalid>
wrote:

>David Skelton wrote:
>
>>>>But, ABS does not
>>>>work so well in the very wet or icy conditions.
>>>
>>> Sure it does. It can't perform miracles, however.
>>
>>No, it doesn't work so well in slippery conditions.
>
>I'd love to see you prove that statement. It's a fact beyond dispute
>that it aids stability and control...
>
>>In slippery conditions, it is much easier to lock all four wheels at once
>>with a stomp on the brake pedal. Then the ABS controller cannot detect
>>wheels turning at different speeds which is required to activate the ABS
>>system.
>
>A) Does that really work? B) Why the HELL would you want to do that?


When you have really sloppy conditions the "high viscosity water"
causes the (wide) tires to "hydroplane" and braking causes the tire to
skid immediately. Without ABS the "skid" gets a chance to scrape down
through the slush and actually "find" pavement - allowing the vehicle
to stop. Since this does not always happen simultaneously on both
sides of the car, or better yet on all 4 wheels at once, a skewing
skid occurs - but the vehicle does slow down. By releasing the brakes
momentarily to regain directional control and then trying again, it is
possible to actually stop the car - and if you know how to drive, also
stop it straight on the travelled portion of the roadway.

With ABS when this happens the ABS releases the brake before it can
scrape down to the pavement, so traction is not regained. The good
news is no skewing skid results. The bad news is the car does not slow
down, and although you can easily stay on the travelled portion of the
roadway, it may well be occupied by something else made of steel and
rolling on 4 wheels. - or a pedestrian - which you will undoubtably
hit.
Straight on.
And hard.

IF you can fool the ABS into not releasing, under those conditions,
you have a chance of getting stopped - perhaps sideways.
In my experience I've NEVER been able to trick the ABS into allowing
all 4 wheels to skid - they always release.