From: Bernd Felsche on
Doug Jewell <ask(a)and.maybe.ill.tell.you> wrote:
>Sekula wrote:
>> http://news.ninemsn.com.au/article.aspx?id=1029332

>Hmmm...
>So, we have one of two scenarios:
>1. there are a lot of stupid drivers around, who all happen
>to drive toyota priarses. (ok, it is tempting to say their
>choice of vehicle proves their low intelligence).

Gullibility.

>2. quite likely that there is a fault in the computer
>control of the throttle-by-wire, where it seems the computer
>"locks-up" and no longer responds to input from the driver.

Much as I despise the waste of the Pious, those computers have at
least one watchdog timer that issues an interrupt if the watchdog
isn't tickled regularly by the working computer. Safely-critical
systems have hardware interrupts wired to the real world that cannot
be ignored; and are serviced by the interrupt handler.

>If this is the case, then I doubt the computer could be
>relied upon to accurately record events such as brake pedal
>press, so IMO just because the computer says it wasn't
>pressed, doesn't provide any proof one way or the other.

It provides the information that the computer didn't believe that
the pedal had been pressed. It's a step forward, but it doesn't
justify a leap to a conclusion.
--
/"\ Bernd Felsche - Innovative Reckoning, Perth, Western Australia
\ / ASCII ribbon campaign | If builders built buildings the way programmers
X against HTML mail | wrote programs, then the first woodpecker that
/ \ and postings | came along would destroy civilization.
From: D Walford on
Noddy wrote:
> "D Walford" <dwalford(a)internode.on.net> wrote in message
> news:4ba36d5d$0$8832$c3e8da3(a)news.astraweb.com...
>
>> LOL but I doubt such dumb behavior is confined to Americans.
>
> You're not familiar with the term "Only in America", huh? :)


I am, they certainly have more than their share of dumb bastards that's
for sure but they are not entirely alone:-)


Daryl
From: Noddy on

"D Walford" <dwalford(a)internode.on.net> wrote in message
news:4ba402b5$0$27810$c3e8da3(a)news.astraweb.com...

> I am, they certainly have more than their share of dumb bastards that's
> for sure but they are not entirely alone:-)

I wouldn't think so, but for a "leading edge" country they certainly seem to
have more than their fair share of fuckwits.

--
Regards,
Noddy.


From: Clocky on
Sylvia Else wrote:
> On 19/03/2010 11:02 AM, Sekula wrote:
>> http://news.ninemsn.com.au/article.aspx?id=1029332
>>
>
> While I suspect that the report is correct, I'd have to wonder about
> the wisdom of assuming that logs from a computerised control system
> accurately reflect what the driver was doing when something is alleged
> to have gone wrong.
>
> I suppose a Prius's brake pedals are linked directly to the brakes,
> but the throttle pedal presumably goes via the computer. If the input
> to the computer said that the pedal was fully pressed, then the
> computer would both act accordingly, and log the fact that the pedal
> was pressed. Whether or not it actually was.
>

The accelerator pedal gives more then one reading and they are completely
different so a reading of fully open or fully closed (or any other) reading
is not the same as the reading you would expect from a disfunctioning pedal
or ECU. These values are recorded and can be compared with expected readings
from other sensors as well.




From: Clocky on
Doug Jewell wrote:
> Sekula wrote:
>> http://news.ninemsn.com.au/article.aspx?id=1029332
>>
> Hmmm...
> So, we have one of two scenarios:
> 1. there are a lot of stupid drivers around, who all happen
> to drive toyota priarses. (ok, it is tempting to say their
> choice of vehicle proves their low intelligence).
>

Stupid is reserved for godcrawlers, I prefer to call Prius buyers ignorant
which is kind or ironic since it's another kind of stupid that still thinks
humans have had no influence on the climate despite the overwhelming
scientifically backed evidence but that's another issue.

> 2. quite likely that there is a fault in the computer
> control of the throttle-by-wire, where it seems the computer
> "locks-up" and no longer responds to input from the driver.

The ECU can't lock up and hold the throttle open at the same time nor can an
ECU partially lock up. A faulty accelerator pedal sensor would show up as
the ECU compares two (or more possibly) different readings from the sensor
to determine the actual throttle position. If one of those readings doesn't
correspond with the expected reading from the other a fault is set and the
vehicle will likely go into one of it's fault modes with restricted
driveability.

> If this is the case, then I doubt the computer could be
> relied upon to accurately record events such as brake pedal
> press, so IMO just because the computer says it wasn't
> pressed, doesn't provide any proof one way or the other.
>

Redundancy is built in though, so other readings can be used to determine if
the brakes where applied.

> I hope to hell the brakes in these things are traditional
> hydraulic systems directly coupled to the brake pedal.
> Heaven help us if they are brake-by-wire also.

One would hope not!


First  |  Prev  |  Next  |  Last
Pages: 1 2 3 4 5 6
Prev: ho hum more holden recalls
Next: Vehicle Security Alarms