On Mar 2, 9:01*pm, (Doug Miller) wrote:
In article , (Don Klipstein) wrote:
In , Doug Miller wrote:
The thing that really stood out to me was the statement by Toyota's
president that they're going to look into programming a brake override
for the throttle.

I have only one question: WHY IN GOD'S NAME WAS THAT NOT THERE FROM THE
BEGINNING?

**Programming* a throttle override by the brake? *As in relying on lack
of electronic malfunction in order to have the brake reliably apply an
override onto the throttle?

Since the override becomes necessary only in the event of a throttle
malfunction, for the override to not work would require a second malfunction.
Clearly two simultaneous malfunctions are *far* less likely than any single
malfunction.


That's obviously totally false. Let's say I have a single computer
that is running the throttle, the shift interlock, and the engine shut
off via the start/stop button. Actually that doesn't sound that far
fetched. Clearly you could write a program in such a way that the
program under certain conditions goes into a program loop where it
will no longer respond to either a change in throttle input or the
stop button and will also not unlock the shift. That's a single
program failure, not two simultaneous malfunctions.



For additional safety, a mechanical interlock could be constructed -- but the
electronic systems are more reliable.

I think it's arguable which are more reliable and which can be
designed to better fail safely. However for it to do what it needs
to do the interlock needs to be totally seperate from the computer
commanding the throttle.