So if you get a flat battery you can't turn the front wheels? Call me old fashioned, but....
15th January, 2013 @ 3:54 p.m. (California Time)
It shocks me, the US government is going to allow Steering by Wire? I agree with Ozuzi, I figured some sort of mechanical and hydraulic linkages would be present... But I suppose this makes it simplier, but what happens when things go wrong?
A couple of years ago, there was this Corvette Z06 came through the dealership. Had a fulty APP (acclerator pedal position sensor). The cool thing was, it used 2 voltage references, a 2.5 and 5v reference. They were out of sync, wound up being a speck of corossion on a pin to the PCM (powertrain control module) causing intermittent contact. Maybe they have something similar....? The whole drive by wire thing is cool though, amazing how fast computers are these days! :-)
15th January, 2013 @ 7:51 p.m. (California Time)
Ozuzi, after you jump start the car it goes through a relearn procedure like all of the modern throttle by wire cars at every engine shutdown 1996 and 1997 VAG cars had to be told to do it, now days they do all by themselves, though I worry about steering feedback
15th January, 2013 @ 8:57 p.m. (California Time)
Steering system faults aside...
The claim: “transmitting the driver's intentions to the wheels faster than a mechanical system.”
It may be true but it is marketing spin. Is it true ?? (Who knows)
The "Drivers intention" is transmitted through the steering system at the speed of sound in the components (plus any slop in the system)..... (Just how fast can you turn the steering wheel. or respond to anything.)
SOS in steel ~ 6000 m/s
Ok Light speed through an electric wire (forgetting the delays caused by the electronics in-line) 300 000 000 m/s it is a bit more...
3 metres of wire versus 3 metres of steel..
Time through the steel = 0.4 miliseconds (that is pretty fast) Much faster than any himan response time..
Time for electricity to flow through the wire = 10 nanoseconds
However if there is half a millisecond processing delay, the steel beats the fly-by-wire....
Will you note the difference...
Obvious benefits with a fly by wire system is that the feedback can be adjusted, the response can easily be varied the control algorithm can be tweaked and updated.. The benefits do outweigh the downsides (spin
notwithstanding) Until this non-redundant critical system fails.... I would think that the Law in many countries will require either at least double redundancy in the electronics, or a redundant mechanical system so that when it fails it fails in a safe mode. (Most countries design rules will state that a mechanical steering connection must be maintained, as happens in all power assisted steering to this point)
have a nice day.
15th January, 2013 @ 10:50 p.m. (California Time)
“transmitting the driver's intentions to the wheels faster than a mechanical system.”
The drive-by-wire is eventually going to have to transmit its own intentions to the wheels by a mechanical system, isn't it?
Clearly whoever originally wrote this has never driven a decently set-up motor - say, a Mk I Escort or real Mini-Cooper with a fast rack!
16th January, 2013 @ 5:27 a.m. (California Time)
Crazy! No sane person would get into a car with drive by wire. Cars can't afford triple redundancy or have enforced maintenance like planes can. There can be no doubt this will murder people. Nissan is going to go bankrupt after the first $billion lawsuit they lose. Juries are going to hate the idea of no mechanical backup. A legal nightmare in the making. Hasn't anyone learned from Toyota's mistake?
16th January, 2013 @ 8:32 a.m. (California Time)
I think that this is BS. I have not seen this anywhere else. This is the fourth article that I have read on this car and nowhere else was this mentioned. If Infinity has chosen to add this "feature" to the stupidly named Q50 (what was wrong with G37?) then they have lost my faith in them as a manufacturer. I mechanical system is the only way to go with a system as critical as steering. Besides, as MD points out the likelyhood that the driver would notice a benifit is minimal. If that is the case then why invest in such a trivial "upgrade"?
16th January, 2013 @ 8:33 a.m. (California Time)
why invest in such a trivial "upgrade"?
The only reason I can see is to eliminate the traditional mechanical shafts and u-joints that now have to pass through an increasingly crowded engine compartment, and their additional weight.
Whether that is sufficient reason to risk this tech is questionable...
16th January, 2013 @ 10:31 a.m. (California Time)
For all those who may be wondering, here is q text from an article explaining their drive by wire system....
"What they said: Infiniti says it believes its new drive-by-wire system will eventually be an industry standard. A spokesman said the system has several fail-safe modes, along with a mechanical steering connection that engages should all three of the Q50’s steering-control modules fail. Technophobes, fear not."
Q50 vs Lexus IS350?? Q50 seems more refined and probably the best choice.
16th January, 2013 @ 4:53 p.m. (California Time)
Has anybody else had a battery die while you are driving the car
16th January, 2013 @ 6:06 p.m. (California Time)
At least it has a mechanical backup.
Imagine the day when a vehicle has everything by wire, the car is a decade old, the alternator and battery are on their last ergs, you're tooling down the Pickle Parkway in Texas at 85 MPH and the alternator zaps its last gasp, soon after the battery dies.
You're now not in control of an unguided missile. No amount of electrical redundancy (without mechanical or hydraulic backup) can save your butt if there's no source of electricity.
Oh, and the airbags aren't going off when you slam into whatever the car is going to hit. They need electricity to fire their charges.
I suppose the "fix" for that will be "smart" alternators and batteries programmed to not allow the car to move once they reach a certain age or "self diagnose" that they're about to fail.
From the advent of hydraulic brakes until 1954 Hudson had a mechanical backup on the rear brakes. If the hydraulics failed the mechanical system pulled on the parking brake cables. The system works, even on Hudsons that have sat unused for 60+ years.
16th January, 2013 @ 9:14 p.m. (California Time)
nyet, nyet can call me old fashion luddite, I ain't going to pilot a car if it hasn't got a real mechanical linkage.
if its drive by wire then why not just have a joy stick? Just like James Bond where he piloted the Bimmer from the rear seat by commanding a piece of remote no bigger than the face plate of a modern day car stereo.
A plane is a lot more expensive so they can afford more redundant backup system.
16th January, 2013 @ 10:04 p.m. (California Time)
I don't like fly by wire in airplanes an Airbus crashed because the fly by wire system averaged the three control inputs rather than discard the inputs from the panicked copilot that was the opposite of the inputs from the command pilot and other copilot.
17th January, 2013 @ 8:33 a.m. (California Time)