Steering by wire ???

[DWncchs]

Now the Prius's are out of control and crashing,how much horsepower do these cars have ? The women's Prius accelerates from a stop (the width of the street) and takes out a brick wall ,come on ?????
The guy on the freeway is running 94 and says he "CAN'T" shift into neutral ??? Why can't the car be put neutral ? Does the Prius have a shifter or is it a button thing like on a microwave ?
The news said there is no key to turn off.
Guess I need to stop by the Toy dealer and sit in a Prius.

How fu##ing hard would it be to diagnose these problems to determine if they are mechanical or electronic ???

[mrvette]

Originally Posted by clutchdust

Yep, that's pretty much the exact reason I said. What I don't buy is the reduction of weight. You ever see what a race team pulls out of a production car to prepare it for track duty, and there's at least a couple pounds (sarcasm) of wires and computers and other unnecessary crap. I'd be really interested to see an ounce by ounce comparison between a mechanical pedal, cable and linkage vs. a servo pedal, wiring harness and servo inlet.

OUNCES?? on something that weights 2000 lbs....what is the diff, and my point still stands that the computer is gone to sleep, woke up and had coffee by time that injector p/w needs changing....so that is not a valid issue, they'd have to prove that one....I think it's just plain cheeper....the cost accountants have had their say....

and yes, even on a olde tyme vehicle, like my '72 vette, or this 40 y/o motor home I'm working on, I have pulled about 50 miles of excessive wiring outta them, each one.....got a whole recycle bin full of wires, amazing....

of course some went back IN< but even with fuel injection I had wire left over.... I can just imagine a modern car....rather not, really, freeking nitemare.....



as for the column lock, isn't that electronic on some solenoid these days??

kill engine and lock column the same time or is it mechanical like on my olde '72 TT column??, and still no answers about the shifting, what with today's electronic trannies...are there any more mechanical cables into the valve body?? if it's all that computer shit and a bunch of solenoids....anything is possible....

[mrvette]

Originally Posted by DWncchs

Now the Prius's are out of control and crashing,how much horsepower do these cars have ? The women's Prius accelerates from a stop (the width of the street) and takes out a brick wall ,come on ?????
t:

Torque determines how far you take the wall with you.....

[big2bird]

My 03 Silverado is fly by wire. Not ONE issue I have heard of with these trucks. It's not the system, it's TOYOTA's design.
BILLIONS of dollars at stake here. They will let us know AS SOON as the LAWYERS decide they are ready. Not a moment sooner.

[greg75vette]

Whoa, this turned into a computer-hater-convention real fast.

As for the first question, I was told the big reason with why we don't have steer by wire systems yet is due to weight, complexity and cost. For something this crucial, you need the system to be in TRIPLICATE according to federal regulations.
However, this type of system allows a lot of flexibility in terms of how much better a car can be driven, by the average person, in a sticky situation. For example, the stability control system (which will be mandatory on new models soon) will be able to better control steering angle, just as the ECU can better control throttle by wire systems for things like traction control.

Obviously, the better trained driver would not need this and would be able to drive the car better without it, just like many arguments about ABS. However, this is a system for the common man.

Also, this would allow cheaper manufacturing of cars due to the MUCH less complex process of mounting the steering wheel on either side of the vehicle. From a design aspect, this is very nice.

As far as throttle by wire, there are plenty of cars out there (I'm not sure any new model has a cable throttle) have these systems in place and operate fine.

For this prius guy in Ca, I believe he was afraid to shift it into neutral, not that he couldn't. At least that's what they said on the radio this morning. He was afraid it would flip. Yeah, I don't get that either.

I also think a lot of people are afraid to pop it into neutral for one big reason: liability. For example, if you bring your car to a toyota shop with a freshly grenaded engine due to you popping into neutral with the gas pedal pinned so don't lose control of the vehicle, they may try to skirt out of it since you didn't lose control of the vehicle. There's no one but you saying the pedal stuck and nothing saying you would have lost control of the vehicle. Now, if you call 911 and lose control of the vehicle instead of popping into neutral, you now have situation more publicized and toyota may listen a little more closely.
That's my personal conspiracy theory...

[big2bird]

Back when I still did motor controls, and PC's were relatively new, we had "soft" interlocks, and "hard" interlocks. Soft ones were via programmable controllers, and hard ones via relays. Dangerous conditions were supervised via hard locks.
I.E., railroad grade crossings are still controlled via hard interlocks via relays. The circuits are all "supervised" via contacts. If ANYTHING fails, the arms come down. You have seen these down with no train around. This is a safety feature refined by years of practise.
Perhaps a "hard" interlock is in order here.

[mrvette]

Originally Posted by big2bird

Back when I still did motor controls, and PC's were relatively new, we had "soft" interlocks, and "hard" interlocks. Soft ones were via programmable controllers, and hard ones via relays. Dangerous conditions were supervised via hard locks.
I.E., railroad grade crossings are still controlled via hard interlocks via relays. The circuits are all "supervised" via contacts. If ANYTHING fails, the arms come down. You have seen these down with no train around. This is a safety feature refined by years of practise.
Perhaps a "hard" interlock is in order here.

Yeh, no shit.....

[greg75vette]

Originally Posted by big2bird

Back when I still did motor controls, and PC's were relatively new, we had "soft" interlocks, and "hard" interlocks. Soft ones were via programmable controllers, and hard ones via relays. Dangerous conditions were supervised via hard locks.
I.E., railroad grade crossings are still controlled via hard interlocks via relays. The circuits are all "supervised" via contacts. If ANYTHING fails, the arms come down. You have seen these down with no train around. This is a safety feature refined by years of practise.
Perhaps a "hard" interlock is in order here.

Agreed. This is what is done for throttle by wire. If anything in the system fails, the throttle plate goes to the idle position (closed) and you are able to pull over safely while gradually slowing down.

Sidebar: This is also why I believe Toyota when they say this is a mechanical problem, not software. The system has no way knowing if the pedal is frozen due to mechanical failure or the pedal is being held down with a foot.

However, what is the "safe" position for steering? If this fails while driving, you can't just lock the steering into any direction, or let it float. This is why with a system like this, there would have to be triple redundancy, either it be through 'soft' or 'hard' interlocks. I would assume a combination of the 2.

[big2bird]

Originally Posted by greg75vette

Agreed. This is what is done for throttle by wire. If anything in the system fails, the throttle plate goes to the idle position (closed) and you are able to pull over safely while gradually slowing down.

Sidebar: This is also why I believe Toyota when they say this is a mechanical problem, not software. The system has no way knowing if the pedal is frozen due to mechanical failure or the pedal is being held down with a foot.

Probably something simple stupid, but they still haven't REALLY found it. So. Cal. cars around here that have been "fixed" are stilll failing.

[greg75vette]

True, but from what I've read/seen/heard, it appears to be a mechanical lock-up in the pedal. With that being said, I'm not a toyota engineer and obviously we simpltons haven't been shown exactly how it has failed.

Only time will tell...