Honda "Drive by Wire" question... what if the power goes out?

Pete C. wrote:
> jim beam wrote:
<snip>
>>>
>>>SUVs are *not* unstable by the wildest stretch of the imagination.
>>
>>that's not correct pete. the dynamic that causes all the rollover
>>problems in suv's is transition from a lean in one direction while
>>turning in the other - a rapid s-bend. most suv's will flip. that's
>>fundamental instability.
>
>
> That is exactly the same maneuver that results in cars rolling over as
> well. My point still stands. SUVs are *not* unstable, they simply have
> lower limits to that stability. Unskilled drivers will roll either, they
> just do it more often in an SUV since it's less forgiving of their lack
> of competence.
>
>
>>it's been known about for ages, but the u.s.,
>>in typical response to lobbying pressure, chooses to test suv's in the
>>one mode most are known to pass, the j-bend test. why is this? if you
>>dig about in the nhtsa web site, you'll see the explanation - it's
>>political - they can't impliment a test that would condemn a significant
>>portion of vehicles in domestic production. you can bet your rear end
>>that if this same test condemned imports, it would be implimented tomorrow.
>
>
> It's been known for ages that the typical driver has insufficient
> training. It's politics that prevent upgrading driver training and
> licensing standards. As with everything else, it is more palatable to
> blame an inanimate object or large corporation than to blame the person
> that actually caused the problem.
>
> Pete C.
>

i disagree. while in an ideal world, driver training would be perfect,
it's never going to be. go sit with my grandmother as she drives her
crown vic. "why are you sweating? - the air conditioner's on max". no
kidding grandma.

reality is, vehicles need to take account of the "average" driver. i
personally dislike abs because it doesn't offer me choices on my braking
limits. but for my grandmother, it's the /only/ way to go - there's no
amount of driver training will /ever/ get her up to a standard that
would ever allow her to steer out of a skid or have /any/ chance of
fighting wheel lift in an suv. i therefore say that while /you/ may
feel you can control an suv competently, it's unrealistic to expect
everyone else to approach the standard necessary. the only responsible
approach is [and i hate to say this] do what the europeans do and go for
active stability control on suv's. that vehicle platform is just not
capable of being "safe" without it.

wrote:
> "jim beam" > wrote in message
> ...
>
>
>
>
>> one that allows
>>significant perfomance benefits, control benefits /and/ reliability
>>benefits?
>
>
> ******What significant performance, control, and reliability benefits do you
> see from the by-wire system ( as it has been defined as applying to the
> Honda
> application)?
>
>
you're tooling along at 20% throttle, 2k rpm. you want to accelerate
and go to 100% throttle. but your engine's only good for wot above 4k
rpm. you need to shift. but it's a stick and you don't. but you do
get some pull up to about 60% throttle. why throw away 40% that's not
being utilized? electronic control saves you gas.

ok, so you don't drive a stick, but you have an old hydraulic automatic.
again, you want to go up a steepish hill and because it won't pull at
low rpm's, you need the transmission to shift. it won't until you kick
it to the floor because the transmission can't detect load, only whether
you've operated the kickdown. sure, you can manualy over-ride, but why?
electronic controls know exactly the engine load and can therefore
determine the grade of hill. selection of gear ratio and throttle
position is /much/ better.

besides, what's with this misconception that we need direct throttle
linkage? anyone here ever worked on diesels? anyone here know that the
diesel govenor does? there's no direct linkage to fuel injection on a
diesel - it's all done by the govenor. if that thing fails, you have
ZERO engine control. diesels have been like this from day 1.

Flyingmonk > wrote:
>
>Mercedes' "break by wire" system senses traffic ahead of you and
>applies the breaks for you to maintain distance from car in front of
>you. It controls spcae in front of you in flowing traffic, as in long
>highway hauls.

Thereby leaving you more time to talk on your cellphone!
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 2005-11-19, Pete C. > wrote:

> I think you're referring to the Throttle Position Sensor, a.k.a. TPS,
> not electronic throttle. Engine computers have had sensors to monitor
> throttle position for years, at least since the advent of fuel
> injection. This has nothing to do with electronic throttle control where
> the computer actually has control of the throttle position.

I stand corrected. Thanks for clearing that up.

nb

notbob wrote:
> And sure enough, the throttle valve opening was
> a 0-10 volt range from all the way closed to all the way open.

Zero to five volts.

Toyota MDT in MO

">> The idea of full-on "steer by wire" with NO mechanical
> backup is STUPID.

As I understand it, electric steering is "electric power assisted" steering.
That it, instead of the tradtional hydraulic assist system, there are
electrical-mechanical assists (stepper motors maybe come to mind) to the
standard rack and pinion.

Stewart DIBBS

>
> ok, so you don't drive a stick, but you have an old hydraulic automatic.
> again, you want to go up a steepish hill and because it won't pull at
> low rpm's, you need the transmission to shift. it won't until you kick
> it to the floor because the transmission can't detect load, only whether
> you've operated the kickdown.

Wrong. Remember the vacuum operated modulator valve? They worked great
until the diaphram broke and ATF got sucked into the engine. Those were
the days, man, those were the days....

sure, you can manualy over-ride, but why?
> electronic controls know exactly the engine load and can therefore
> determine the grade of hill. selection of gear ratio and throttle
> position is /much/ better.
>
> besides, what's with this misconception that we need direct throttle
> linkage? anyone here ever worked on diesels? anyone here know that the
> diesel govenor does? there's no direct linkage to fuel injection on a
> diesel - it's all done by the govenor. if that thing fails, you have
> ZERO engine control. diesels have been like this from day 1.
>

"jim beam" > wrote in message news:BYCdnbjNyIqly-
> you're tooling along at 20% throttle, 2k rpm. you want to accelerate
> and go to 100% throttle. but your engine's only good for wot above 4k
> rpm. you need to shift. but it's a stick and you don't. but you do
> get some pull up to about 60% throttle. why throw away 40% that's not
> being utilized? electronic control saves you gas.
>
> ok, so you don't drive a stick, but you have an old hydraulic automatic.
> again, you want to go up a steepish hill and because it won't pull at
> low rpm's, you need the transmission to shift. it won't until you kick
> it to the floor because the transmission can't detect load, only whether
> you've operated the kickdown. sure, you can manualy over-ride, but why?
> electronic controls know exactly the engine load and can therefore
> determine the grade of hill. selection of gear ratio and throttle
> position is /much/ better.
>
> besides, what's with this misconception that we need direct throttle
> linkage? anyone here ever worked on diesels? anyone here know that the
> diesel govenor does? there's no direct linkage to fuel injection on a
> diesel - it's all done by the govenor. if that thing fails, you have
> ZERO engine control. diesels have been like this from day 1.


Few use manual transmissions now, and even if they did, the 'by wire'
technology
would not change a thing.

Even with diesels, 'by wire' actuation does nothing unique.

IF automated highways ever became a reality, then a totally electronic
system
might be the way to go...collision avoidance, route selection, traffic flow
optimization,
police interception, etc...all might be controlled by computer...

I think I will stay home if that ever happens...

John S. wrote:
> David E. Powell wrote:
> > Hi there.
> >
> > I have been looking at the new Honda Civic, it's pretty sweet, and the
> > welds and everything are as nice as anything I have ever seen. I just
> > have a question about the "Drive by wire" system that they are supposed
> > to have.
> >
> > What happens if the Engine dies on you? In my current car, my timing
> > chip went once and the engine went out. I had enough steering control
> > left, even without power steering, to pull my car over before it came
> > to a stop. If the drive by wire system has no "real" or active
> > connection, how can it work if the engine or electronics quit on you?
> > Are there any backups built into the system in case any of that stuff
> > happens? And what if your battery dies and you need to push the car?
> > Can you turn the steering wheel to adjust your wheels when you push the
> > car?
> >
> > Much thanks, sorry to bother.
> >
> > David
>
> I wouldn't worry about not having a mechanical connection.
>
> We have had electronic throttles for a long time with very few
> problems. We have also had hydraulic brakes since the 1930's with very
> very few problems of total failure.

Yet brakes still fail now and then, from lines going bad, slipping,
etc.

My only question, however, was regarding the steering should power be
lost. I have had experience with an engine going offline while at
speed, and would prefer to maintain some steering control if I ever
found myself in a similar situation! Dittos for you or anyone else hwo
happened to be out on the road with me. I still am not sure about
whether Honda has or is going to have DBW steering, and as for
throttle, I asked at another dealership today. None of the sales staff
really had any specifics on how DBW throttle works, or if they are
going to do steering that way. The write up book I saw on the features
and specifications for the forthcoming Honda SI Civic (Which I had
heard would have it at the other place) had no mention at all of any
DBW throttle or features. If they are trying to "slip it in there" like
that at Honda, that's pretty sneaky. Truth be known, if the one
salesperson hadn't told me, I might never have known to ask.

David

Were talking the electronic throttle body=no throttle cable. and it sends
the 3 signals along the same wire (I believe
Now I'm gonna have to find that book...


--
Stephen W. Hansen
ASE Certified Master Automobile Technician
ASE Undercar Specialist

http://autorepair.about.com/cs/troub...l_obd_main.htm
http://www.troublecodes.net/technical/

"Pete C." > wrote in message
...
> Steve H wrote:
>>
>> I was taught this once, but like other stuff we don't use, you forget it
>> go
>> in a general since, it works like this:
>>
>> In the GM throttle body, it has 3 electronic signals to compare to, one
>> being a mirror of itself. If it looses two of them then there may be an
>> issue (I believe) If you were to have an catastrophic failure, the car
>> goes
>> to limp home mode and gives you a crawl speed.
>>
>
> I've not seen any redundant sensors in any GM vehicle I've worked on. My
> current '97 truck with the 7.4l Vortec V8 certainly has no redundancy in
> it's sensors. A single sensor each for throttle position, intake air
> temperature, mass air flow, etc. Certainly if it looses one of the
> sensors to the extent it can detect it, it will enter limp mode, but
> absent redundant sensors, there are failure modes that the computer has
> no way to detect.
>
> Pete C.