Another unexplained acceleration

Another unexplained acceleration

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The Wookie

13,964 posts

229 months

Friday 3rd February 2017
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I think good old Occam's Razor applies here

Alex_225

6,264 posts

202 months

Friday 3rd February 2017
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I'd be suspicious of anyone claiming that their car surged forward on it's own accord. Fly by wire throttles are all over the place and yet we don't hear of this occurring with any regularity (thankfully).

Yet we do hear about or even see cases of people mistaking pedals and flying through shop windows, into parked cars etc. Even on Youtube there's footage of that.

The chances of an 80 year old person, mistaking a pedal and accelerating instead of braking, in my mind seems more likely than the car surging. Due to the consequences of the incident, it may be that the driver simply doesn't want to imagine they were responsible for killing someone.

saaby93

Original Poster:

32,038 posts

179 months

Friday 3rd February 2017
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OverSteery said:
as I said, I am no expert in this field. given the nature of this system, I would expect it would be logging many recorded values with a high sample rate to NV memory,
If it was wouldn't we see that in the reports?
Where is the 'Logs are taken 10 times per second and we can see that the throttle sensor thinks it's fully down'
Which isn't the same as the throttle being down as there may be a sensor failure (see air France crash)
It doesnt have to happen very often - once is enough and this may be that once

J4CKO

41,628 posts

201 months

Friday 3rd February 2017
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saaby93 said:
J4CKO said:
So, Nissans arent crashing all over the place with engines blaring with stuck throttles, never heard of it, of course any system can have a fault but do I believe an 82 year old lady who is trying to avoid a death by dangerous driving charge versus a multinational car company of around the same age, with millions of vehicles in the field not causing the same problem, it isn't a hard one, some older folk do seem to get to a point where they have this kind of accident, if you hear a car revving with the clutch slipping it is usually someone of advanced years.

I may be doing her a disservice but its a pretty low probability that the car, since found to be operating correctly was at fault.
youve fallen into a trap there
There are loads of 82 year old ladies that aren't crashing and there are loads of Nissans that arent crashing
You could ask which are there more of?
But does either way bring us closer to the cause of this

It's too easy to say the software works therefore it must always work
I'm glad the software in my TV recorder isnt controlling the throttle. Ok it doesn't fail much but it does randomly very very occasionally
What is the failure mode trapping they've built around the throttle?
Without knowing that you cant say without doubt she's guilty as there may be the slim chance too it's the car
I did caveat what I said, it may be the throttle and it may not be her fault and I was doing her a disservice.

Not sure you can really compare directly the software in a DBW throttle and a PVR, well you can, it is just software but I should imaging the PVR is immeasurably more complex and runs a complete Operating System and the DBW throttle is a lot simpler, of course any system can go wrong but I have seen a lot more dodgy driving by Octogenarians than failed DBW systems, and they have only been on a Maserati.

I would say that I have also seen more problems with conventional throttles than DBW ones.

This just seems like the anything to get out of it defense


Jimmy Recard

17,540 posts

180 months

Friday 3rd February 2017
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She ran over a pedestrian and killed that pedestrian. Just own up - you made a mistake and didn't get away with it.

WokingWedger

1,030 posts

206 months

Friday 3rd February 2017
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I don't think it is anything to do with electronic throttles versus the old cable control.

I can understand how this sort of thing happens.

Don't these cases of 'pushing the wrong pedal' (which it almost certainly is) only happen in Autos ?

Sounds obvious I know, but think about it.

You are creeping forward (or back) without touching any pedals, but 'covering' one of them, possibly the throttle because it often doesn't quite creep faster enough.

An emergency happens and you get it wrong (you had been 'covering' the throttle)but stamp on it thinking you were covering the brake.

Doesn't happen with manual cars as you have to know where your feet are to make it move.

As there are a lot more autos out there in the hands of older people (and young)we are bound to see more of it.

Nothing to do with electronic throttle IMO

durbster

10,284 posts

223 months

Friday 3rd February 2017
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Phil Dicky said:
t400ble said:
Shes pressed the wrong pedal, simple as that
This ^^^^^
This again, in bold.

Same goes for the Toyota sudden acceleration "scandal", which can also be attributed to human error.

If a throttle sticks open and you put the brakes on, your car will stop. And not in a dramatic way - it'll just stop a bit later than it would if the throttle was closed.

Brakes will beat engines every time.

donkmeister

8,205 posts

101 months

Friday 3rd February 2017
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WokingWedger said:
I don't think it is anything to do with electronic throttles versus the old cable control.
Exactly this. The first case i read about of this sort involved a Micra auto and i read it back in 94 or so. No drive by wire, but the driver was of a similar demographic.

Nezquick

1,461 posts

127 months

Friday 3rd February 2017
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She's obviously pressed the wrong pedal.

The problem is that she'll have had the accident and immediately got out of the car insisting it was the car's fault, because that's human nature - we don't like to admit having made a stupid error. Over time, before the trial, she'll have then convinced herself that she did not press the accelerator and her view will never be changed. She will be convinced she's telling the truth.

saaby93

Original Poster:

32,038 posts

179 months

Friday 3rd February 2017
quotequote all
Jimmy Recard said:
She ran over a pedestrian and killed that pedestrian. Just own up - you made a mistake and didn't get away with it.
She said she would if that's what had happened, she wouldn't have put herself through 3 months of this
Mind you I guess some people would just fez up to it for an easy life, even if they thought they hadn't hit the wrong pedal
We've seen that with other traffic offences - pay up, move on

The Wookie

13,964 posts

229 months

Friday 3rd February 2017
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saaby93 said:
f it was wouldn't we see that in the reports?
Where is the 'Logs are taken 10 times per second and we can see that the throttle sensor thinks it's fully down'
Which isn't the same as the throttle being down as there may be a sensor failure (see air France crash)
It doesnt have to happen very often - once is enough and this may be that once
Good example with the Air France crash, so there were still working, accurate sensors, the computer told the pilots that the dodgy reading was likely inaccurate, and the co-pilot crashed the plane because of a basic lack of aircraft handling skills

Of course it's not impossible that she could have had a temporary and unrepeatable brake failure simultaneously with either a multiple, temporary, unrepeatable throttle pedal/butterfly position sensor failure, or an obscure and unrepeatable total failure of the car's entire electronic control system...

Or maybe she just pushed the wrong pedal and is in total denial.

Jimmy Recard

17,540 posts

180 months

Friday 3rd February 2017
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saaby93 said:
She said she would if that's what had happened, she wouldn't have put herself through 3 months of this
Mind you I guess some people would just fez up to it for an easy life, even if they thought they hadn't hit the wrong pedal
We've seen that with other traffic offences - pay up, move on
She may well believe she was standing on the brake, but that don't make it so.

98elise

26,644 posts

162 months

Friday 3rd February 2017
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Its very simple to design a fail safe. For example the pedal operates two potentiometers in opposite directions. This will give two pedal different position signals which can be checked against each other, yet don't behave the same in a failure. It is sudden unintended acceleration, but the cause is very very likely to be the driver.

The problem is that the driver will believe they were pushing down on the brake, because that's what they wanted the car to do.

saaby93

Original Poster:

32,038 posts

179 months

Friday 3rd February 2017
quotequote all
The Wookie said:
Good example with the Air France crash, so there were still working, accurate sensors, the computer told the pilots that the dodgy reading was likely inaccurate, and the co-pilot crashed the plane because of a basic lack of aircraft handling skills

Of course it's not impossible that she could have had a temporary and unrepeatable brake failure simultaneously with either a multiple, temporary, unrepeatable throttle pedal/butterfly position sensor failure, or an obscure and unrepeatable total failure of the car's entire electronic control system...
And thats the issue
You cant say 100% it wasnt a system failure, there's nothing in the reports to say it ws a fail safe system
so you cant say beyond doubt it was her fault
QED
Dont want to lock her up if it was the 1 in a million chance it was the car after all

Stig

11,818 posts

285 months

Friday 3rd February 2017
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"The 82-year-old"

Case closed.

The Wookie

13,964 posts

229 months

Friday 3rd February 2017
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saaby93 said:
nd thats the issue
You cant say 100% it wasnt a system failure, there's nothing in the reports to say it ws a fail safe system
so you cant say beyond doubt it was her fault
QED
Dont want to lock her up if it was the 1 in a million chance it was the car after all
You can't be serious

saaby93

Original Poster:

32,038 posts

179 months

Friday 3rd February 2017
quotequote all
Stig said:
"The 82-year-old"

Case closed.
scratchchin
https://www.youtube.com/watch?v=y5dy9URkLFI
hehe


durbster

10,284 posts

223 months

Friday 3rd February 2017
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98elise said:
Its very simple to design a fail safe. For example the pedal operates two potentiometers in opposite directions. This will give two pedal different position signals which can be checked against each other, yet don't behave the same in a failure. It is sudden unintended acceleration, but the cause is very very likely to be the driver.
Why add complexity?

It doesn't matter if the accelerator is flat to the floor - if you press the brake the car will stop. The problem is how the human mind can trick you into thinking your body is doing something it's not.

The only reliable solution is autonomous cars.

mac96

3,791 posts

144 months

Friday 3rd February 2017
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I am in the 'more likely to have pushed wrong pedal' camp.

But how can a foot slipping off the pedal, or pushing the wrong one by accident, deserve a prison sentence- it is ludicrous. and yet she seems to be looking at a minimum 2 year tariff ?(happy to be corrected on that).

There seems to be no suggestion of any other issues with her driving apart from this isolated error. She was not in any way deliberately driving dangerously, nor was she driving a in a generally dangerous way (ill judged overtakes, driving at 90mph down the high Street etc)

If this momentary error is really all there was to it, surely most drivers would be guilty of at least Dangerous Driving at some time or other, and just been lucky that no one was hurt. Including the prosecutor, the judge and the Nissan expert witness.

Roger Irrelevant

2,943 posts

114 months

Friday 3rd February 2017
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The Wookie said:
I think good old Occam's Razor applies here
Yep I'll go with that.

Oh but wait, the lady said that if she'd pressed the throttle she'd have admitted it. That throws a whole different complexion on it. So now it's not just:

'mystery throttle error for which there is no explanation that has failed to manifest itself in millions of other cars with the same system vs old lady gets driving wrong',

it's now:

'mystery throttle error for which there is no explanation that has failed to manifest itself in millions of other cars with the same system vs old lady gets driving wrong and is mistaken about it'.

...Occam would have had a tough time with that one.