Many of you will have seen reports of Toyota cars running away out of control - I saw a link to a site describing Toyota's bad software practices
that may well have caused unwanted acceleration:
Toyota software report
It's a bit technical in its description, but it's not hard to get the gist of what they're saying - Toyota bodged the
'throttle-by-wire' software development and didn't understand how to test it (or chose not to do it properly). One problem was found
where a driver experiencing unwanted acceleration had to take his/her foot OFF the brake pedal to regain control - not easy to do, even if you know
it's required (which, of course, they didn't).
There's a lot to be said for a bit of steel cable between the accelerator pedal and the engine's fuel system...
Exactly!
At least if the that single bit of wire fails the throttle closes.
Toyotas were never just as good when they started making them outside Japan, If the sticker on the windscreen said 'Made in Japan' you were fine. If it's made in the UK you took the chance that you could get a Monday morning car and if it's made in France then good luck to you.
My default reaction when the throttle sticks (has happened on my older cars) is to key off. Did the toyota system remove the ability to do this?
My brakes ALWAYS overpower my engine. I'm still confused as to how this ever became a problem.
quote:
Originally posted by coyoteboy
My brakes ALWAYS overpower my engine. I'm still confused as to how this ever became a problem.
quote:
Originally posted by rdodger
Exactly!
At least if the that single bit of wire fails the throttle closes.
If I used recursion or ignoring/switch off casting warnings (two of the items listed) I'd sack myself on the spot.
Sounds like the job was given to a fresh graduate with only windows/mac/unix experience and minimal oversight. Code obviously wasn't properly
unit tested or even have a static code analysis (with MISRA checking turned on).
Shocking.
Personally I don't see the problem in a manual car - you dip the clutch (or do clutchless downshifts) when you brake don't you?
I did a skidpan course a few years ago. The first time I braked on 'ice' I hadn't pressed the clutch in fast enough and the engine
stalled. The instructor then said "OK, now imagine you've just done this on a dual carriageway, and there's a 38 ton truck doing 60
approaching you...."
By the way, don't do what coyoteboy suggests - you will almost certainly turn the key completely off, which engages the steering lock. I know a
Mercedes mechanic who did this test driving a customers almmost new S500 looking for a sticky thottle problem, when the throttle stuck open, he
turned the ignition off,which engaged the steering lock, he went straight through the hedge and wrote the car off. He'll tell you he feels
luckyto be alive since he had quite a bit of pace on at the time. It was an auto though so his other options were a bit limited.
Be careful out there!
Hugh
Scary stuff, and yes I would go for the key to the off position route, and engage the stearing lock, and knowing my luck be right next to a cliff at
the time!
And what I personally find even more scary is modern planes with their fly by wire stuff
As BA used to say 'I ain't getting on no plane' seem a very sensible attitude to me.
quote:
Originally posted by TheGiantTribble
And what I personally find even more scary is modern planes with their fly by wire stuff
quote:
Originally posted by iank
If I used recursion or ignoring/switch off casting warnings (two of the items listed) I'd sack myself on the spot.
quote:
Originally posted by TheGiantTribble
....I would go for the key to the off position route, and engage the stearing lock...
I've driven a fair few drive-by-wire cars, and more than a few conventional cable throttle cars.
The only ones on which I've had runaway or sticky throttle have been on the conventional throttles ironically! One was a diesel pump runaway,
which really couldn't care less whether you had a mechanical cable or servo attached to it, throttle did nothing. The other was in a mini which
had its lovely SU carb throttle spindle get stuck in the OPEN position. Had to engine off to kill ignition.
I have absolutely no problem driving a car where the throttle is controlled by a computer. I've yet to come across a car where the brakes
can't overpower the engine, and you can ALWAYS ignition off, even in cars with keyless button start (yes, I've checked this!).
To put it into perpective..
Toyota built 7,000,000 cars since the start of THIS YEAR. Even if 100 of them had unintended acceleration (and they didn't), I'd take those
odds.
(P.S. I don't work for Toyota, just trying to balance out the argument! )
quote:
Originally posted by iank
If I used recursion or ignoring/switch off casting warnings (two of the items listed) I'd sack myself on the spot.
Sounds like the job was given to a fresh graduate with only windows/mac/unix experience and minimal oversight. Code obviously wasn't properly unit tested or even have a static code analysis (with MISRA checking turned on).
Shocking.
Fly by wire.......... PITA
It stops me left foot braking my Vectra as soon as I put my foot on the brake the throttle backs off
Oh well at least the twin 40's on the kit stay WIDE open with my foot on the brake
RD
forget throttle by wire....I've recently read about "steering by wire" making it's way onto the market!!!
Now that one is scary if it was to go wrong!!
quote:
By the way, don't do what coyoteboy suggests - you will almost certainly turn the key completely off, which engages the steering lock.
Yeah I have to say that removal of steering control from the driver does scare the living daylights out of me - really something I'd not be comfortable with. Like brakes - really wouldn't be happy with that being removed. I'm sure it'll all be double redundant, but I'm an engineer and I know how badly these things could be implemented in a cost-conscious, fast paced market.
I've had numerous automatic cars, and more than a few manual ones, but I've never had any that didn't allow you to go into neutral or turn off the ignition - is this a new 'safety feature'? If so, I've not encountered it yet...
Yes, the Toyotas in question didn't have a key plus had a feature that required you to hold the start button a prescribed number of seconds, make
a certain funny face and put your finger up your butt in order to turn it off but even then it didn't turn off.
The transmission also wouldn't allow you to shift to neutral plus the brakes could not hold the car down on speed.
If you pumped the brakes you quickly lost power assist and on at least one of the cars the brakes were found to be toast afterwards. They simply
weren't up to the task of a long term run away engine. IIRC one of the crashes involved a Toyota mechanic and he didn't fare any better
than people off the street.
Drive by wire does allow some computer controlled features that a hard wired connection doesn't allow, but I'm old fashioned too, I believe
there must be some sort of physical connection even if it's nothing more than a mechanical, emergency OFF switch.
quote:
Yes, the Toyotas in question didn't have a key plus had a feature that required you to hold the start button a prescribed number of seconds, make a certain funny face and put your finger up your butt in order to turn it off but even then it didn't turn off.
quote:
The transmission also wouldn't allow you to shift to neutral plus the brakes could not hold the car down on speed.
quote:
Originally posted by MikeRJ
quote:
Originally posted by iank
If I used recursion or ignoring/switch off casting warnings (two of the items listed) I'd sack myself on the spot.
Sounds like the job was given to a fresh graduate with only windows/mac/unix experience and minimal oversight. Code obviously wasn't properly unit tested or even have a static code analysis (with MISRA checking turned on).
Shocking.
I quite agree, it's almost unbelievable this was allowed to happen. I used to work for a company making railway signalling equipment, and the coding standards and number and strength of reviews for the safety critical stuff was so rigorous that 1) This would have been picked up very quickly, 2) You'd probably have been out on your ear for even attempting to do this.
Even in my current job I'd be kicking backsides if I saw this kind of sloppiness.
Really? I watched the 'murican geriatric Penis head on video where he could not slow down let alone Stop his silly Prius, despite pressing on the
brakes. He drove like this for over an hour .. attempting to stop.
Post mortem showed that the Numpty had no idea of how to use the brakes.. as in : pedal pressure was proportional.
But hey! he had a drivers license .
quote:
Originally posted by coyoteboy
[Again, I just can't see it - not allowing you to shift, maybe, but brakes that can't hold the car - I call nonsense. I've got 300hp 4wd (50% more power than stock) and standard single pot calipers on 260mm discs on a 1.4 ton car and my brakes MASSIVELY overpower the engine ESPECIALLY at speed. Modern brakes are even more over-servo'd than old ones. They'd have to be faulty or totally shoddy/undersized.
Turning off the ignition is going to work fine for someone who knows cars but some people are going to get caught out even if they have the savvy to
turn off the car at the key
When you turn off the ignition the servo brakes are going to stop working and so is the power steering and there will be people who won't know to
allow for this.
I think I'd want to retain the option to shove it into neutral at any time - the engine may end up screaming its nuts off, but at least I can
stop and do something about it.
The point about turning the engine off and losing brake servo assist and power steering is well made... It's amazing how hard it is to turn the
wheel without power steering - not impossible, but a real wrestling match.
quote:
Originally posted by Scuzzle
Turning off the ignition is going to work fine for someone who knows cars but some people are going to get caught out even if they have the savvy to turn off the car at the key
When you turn off the ignition the servo brakes are going to stop working and so is the power steering and there will be people who won't know to allow for this.
I didn't think not having power steering was much of an issue when moving at moderate to high speed? The brakes I can see being an issue though.
To clarify, Toyota, as well as other manufacturers (including the one I work for) have a HOLD TO OFF on push-button ignition systems if the car is in
motion.
You hold the stop/start button for I think 2-3 seconds and it will ignition off (safely), even if you're driving. This does NOT engage the
steering lock, although I'll be honest I've done only a few trials.
This is to stop the engine being accidentally turned off on a motorway if you push the button by accident when reaching for an air vent or other
button.
I appreciate that some people may be unfamiliar with certain cars, but that is no excuse. If you get into a manual car with reverse under 5th rather
than to the left of 1st, and you drive over a child in a car park, are you going to blame the manufacturer because you weren't familiar with the
layout of gears and went forwards instead of backwards?
Equally, not knowing that you lose servo and power steering if you turn the engine off.. This is mentioned in pretty much any literature, including
car manuals, instructions when towing, instructions when being towed.
P.S. The steer-by-wire system which will be shortly introduced (by Nissan I think?) has an entire mechanical system on standby as a failsafe. THIS i
find entirely useless, why even bother with steer by wire, if you have to lug around a full mech setup, when EPAS can deliver all the same features
(auto-steer/parking etc.).
Hadnt heard the news, as im in a bit of a bubble at the moment, but I must say while I wouldn't be a fan of steer-by-wire and dont like electric
handbrakes, fly-by-wire throttle (and planes) done worry me that much.
I have only ever had a throttle-stick moment once, and that was in the kitcar, with a cable. I grabbed the key, which was a mechanical on-off switch,
and killed the engine mid bend while on the brakes. No steering lock.
As for why people done bring a run away car under control, amongst other issues mentioned, sheer blind panic and lack of time has not been mentioned
much. When the kits throttle stuck, and not at full bore, it was about the most frightening thing ive witnessed in a car, and there was not a lot of
road about to have much time to think.
Daniel
quote:
Originally posted by PSpirine
To clarify, Toyota, as well as other manufacturers (including the one I work for) have a HOLD TO OFF on push-button ignition systems if the car is in motion.
You hold the stop/start button for I think 2-3 seconds and it will ignition off (safely), even if you're driving. This does NOT engage the steering lock, although I'll be honest I've done only a few trials.
This is to stop the engine being accidentally turned off on a motorway if you push the button by accident when reaching for an air vent or other button.
quote:
Originally posted by daviep
quote:
Originally posted by Scuzzle
Turning off the ignition is going to work fine for someone who knows cars but some people are going to get caught out even if they have the savvy to turn off the car at the key
When you turn off the ignition the servo brakes are going to stop working and so is the power steering and there will be people who won't know to allow for this.
The brake servo will work just fine with the key turned off providing the engine is still turning, ditto for power steering unless it's EPAS.
Cheers
Davie
quote:
Originally posted by David Jenkins
quote:
Originally posted by PSpirine
To clarify, Toyota, as well as other manufacturers (including the one I work for) have a HOLD TO OFF on push-button ignition systems if the car is in motion.
You hold the stop/start button for I think 2-3 seconds and it will ignition off (safely), even if you're driving. This does NOT engage the steering lock, although I'll be honest I've done only a few trials.
This is to stop the engine being accidentally turned off on a motorway if you push the button by accident when reaching for an air vent or other button.
But would this still work if the car's management system is stuck in a loop? Would it even be monitoring the on-off button, or respond to an interrupt as a result of pressing the button? This sounds like a software solution to a software problem! I'd still prefer a non-computer-controlled override.
I do agree with the rest of your post though - don't blame the car if you can't be bothered to read the manual to learn how it all works.
quote:
Originally posted by PSpirine
Can't stand electric park brakes by the way! They aren't a safety hazard, as they always tend to fail in the ON position when parked, but still bloody annoying.
quote:
"they went solid and stopped working" so he let go of the steering wheel, took his feet off the pedals and waited to hit something (as it turned out that was a 3-4m drop off the side of the banking into some trees) just shows you how some people can react in that situation - personally so force on earth would stop me from standing on the pedals and wrestling with the steering even if they really weren't working at all...
quote:
Originally posted by PSpirine
Especially since most of the reports say the driver "did not know that you have to hold the button to turn the car off".
quote:
Originally posted by scudderfish
quote:
Originally posted by PSpirine
Especially since most of the reports say the driver "did not know that you have to hold the button to turn the car off".
I would like to ask people who claim this what they intended to do at the end of the journey. Leave it idling until it ran out of fuel?
quote:
Originally posted by mcerd1
quote:
Originally posted by scudderfish
quote:
Originally posted by PSpirine
Especially since most of the reports say the driver "did not know that you have to hold the button to turn the car off".
I would like to ask people who claim this what they intended to do at the end of the journey. Leave it idling until it ran out of fuel?
^^ I'm guessing you just touch the button when your not moving to stop it
a bit like a PC - to shut down normally you close all you programs, then touch the on button and it'll shut down properly
(ie. stop the car, but the handbrake on and touch the button to stop the engine)
but if the thing locks up completely you may need to force a hard shutdown - on most PC's / laptops you do that by holding the power button down for ~5 secs
(ok with a desktop PC you can also pull the power cable out the wall - but the car equivalent of that would be disconnecting the fuel lines at 70mph which could be a bit tricky )
[Edited on 31/10/2013 by mcerd1]
I would have said holding a button in for 2 or 3 seconds in an emergency situation was pretty hard mentally. Yes, sat here now, no problem. Sat on the
motorway at 70, probably no issue either.
But, if you are pushing on a bit down some lanes, reach your braking point and start braking, and the engine keeps on pulling you onwards (thus you
are probably already beyond the point where you are going to make it round the corner by the time you decide you need to do something else, like
stopping the engine) I would suggest it takes someone with extraordinary self control to continue to lean forwards (which I have to do to reach the
button in all the push button cars I've driven - all dash mounted buttons) hold a button for 3 seconds (if you can while steering), while
steering throught the Zeds one handed, and not taking your finger off the button to try anything else like changing gear. If you ever look at books on
human interface design for computer systems, the normal figure quoted for a reasonable response that people see as instant is 0.2 seconds or less,
with recommendations that if an action takes more than 0.5 seconds for the computer to complete, then it should give some indication that it is
acting, like displaying an egg timer symbol or similar. Any longer than that and people assume 'its not working' and will start to look for
something else to try.
Personally I'd like to think that dipping the clutch or selecting neutral in an auto would come to mind before trying to turn the engine off, but
once you've decided on a course of action in a stressful situation, people tend to try very hard to achieve whatever they have decided to do. I
have to do incident investigations as part of my job, and it is quite amazing how hard people will try to do the wrong thing once they have decided
that that's the way forward, and afterwards admit that it was obviously the wrong thing if they had stopped for 2 seconds to think about it.
Regards
Hugh
quote:
Originally posted by hughpinder
Personally I'd like to think that dipping the clutch or selecting neutral in an auto would come to mind before trying to turn the engine off
If anyone is interested in 'steer by wire' thing here's the article. Seems way overcomplicated, with many things that can go wrong
compared to the old fashioned set up, and few advantages. Mechanical override that engages if there is an emergency - I wouldn't want to rely on
that when the car is 10 years old and it hasn't operated once in all that time!
http://www.driving.co.uk/features/infiniti/help-someone-s-reinvented-the-steering-wheel/15630
Anyway, Enjoy
Hugh
re: drive-by-wire steering
the only reason I can see for going to all that effort, including the 'simulated resistance' you feel at the wheel is so that they can
compensate for a badly designed steering setup and make it feel like a nice steering setup
is 'fake' feedback at the wheel really going to tell you how the tyres griping in the bends ?
I recon if this takes off then driving most cars is going to give you that same disconnected feeling you get from a arcade driving game or your xbox
etc....
even the engine noise you here is being 'simulated' on some cars just to add to the unreal computer game experience where what you feel and
hear while driving has nothing to do with the reality of whats actually happening
quote:
Originally posted by hughpinder
I would have said holding a button in for 2 or 3 seconds in an emergency situation was pretty hard mentally. Yes, sat here now, no problem. Sat on the motorway at 70, probably no issue either.
But, if you are pushing on a bit down some lanes, reach your braking point and start braking, and the engine keeps on pulling you onwards (thus you are probably already beyond the point where you are going to make it round the corner by the time you decide you need to do something else, like stopping the engine) I would suggest it takes someone with extraordinary self control to continue to lean forwards (which I have to do to reach the button in all the push button cars I've driven - all dash mounted buttons) hold a button for 3 seconds (if you can while steering), while steering throught the Zeds one handed, and not taking your finger off the button to try anything else like changing gear. If you ever look at books on human interface design for computer systems, the normal figure quoted for a reasonable response that people see as instant is 0.2 seconds or less, with recommendations that if an action takes more than 0.5 seconds for the computer to complete, then it should give some indication that it is acting, like displaying an egg timer symbol or similar. Any longer than that and people assume 'its not working' and will start to look for something else to try.
Personally I'd like to think that dipping the clutch or selecting neutral in an auto would come to mind before trying to turn the engine off, but once you've decided on a course of action in a stressful situation, people tend to try very hard to achieve whatever they have decided to do. I have to do incident investigations as part of my job, and it is quite amazing how hard people will try to do the wrong thing once they have decided that that's the way forward, and afterwards admit that it was obviously the wrong thing if they had stopped for 2 seconds to think about it.
Regards
Hugh