Another unexplained acceleration

[saaby93]

http://www.bbc.co.uk/news/uk-england-lancashire-38...

article said:

A driver whose car surged forward and killed a pedestrian has insisted she did not mistake her accelerator for the brake.

Ann Diggles was trying to park her Nissan Qashqai when it hit Julie Dean, 53, in Leyland, Lancashire, in 2014.

The 82-year-old denies causing death by dangerous or careless driving and claims a vehicle fault was to blame.

She told Preston Crown Court: "There is quite a gap between the two pedals. There is no way of mistaking them."
"If I thought I could have made this mistake, I would have said so and not put myself through nearly three years of waiting."

more
http://www.bbc.co.uk/news/uk-england-lancashire-38...

article said:

akuma Nakamura, who is responsible for engine control systems development at Nissan, was asked by prosecutor Richard Archer: "Is it possible, in your opinion, for a malfunction in an electronic throttle to cause sudden acceleration of the vehicle?"

Mr Nakamura replied: "I think that's impossible."

He said the system, in which the computer rather than the driver controls the throttle opening settings, had a self-diagnostic feature and that any problem would have been recorded.

He didnt fully discount that it was possible
The problem is that if the software has crashed - how do you know whats going to be recorded?

[saaby93]

GroundEffect said:

SirSquidalot said:

Still never understand why the cable throttle was replaced with drive by wire.

Because it allows a lot of extra control:

1) Different throttle maps for 'sport' modes etc
2) Different throttle maps per gear (very useful in auto trans)
3) Cruise control on gas engines much simpler

It also introduces almost an infinite number of ways to go wrong, once it's off in the new world outside the happy loop it normally enjoys.
When they went through the Toyota software didnt they discover that all the checking procedures had been based on a working system - they hadnt allowed for what happens when it had gone into lala mode

[saaby93]

OverSteery said:

saaby93 said:

e didnt fully discount that it was possible
The problem is that if the software has crashed - how do you know whats going to be recorded?

whilst you may not record something if there is an error, the error itself should be detectable, even if there is nothing more than a gap in the log files at the time.

It doesnt say there are regular log files - it looks like it only logs a fault if its in a mode to record the fault

[saaby93]

OverSteery said:

- I don't know anything about automotive software, nor whether UK practices are common in Japan,
- but I have worked on safety critical software in the UK

I think it was that difference that was highlighted in the Toyota case

It would be interesting to know whether the throttle control software in this case
or the checking processes around it (hardware or software) were assumed to be safety critical

[saaby93]

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

[saaby93]

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

[saaby93]

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

[saaby93]

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

[saaby93]

Stig said:

"The 82-year-old"

Case closed.

https://www.youtube.com/watch?v=y5dy9URkLFI

[saaby93]

Roger Irrelevant said:

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.

My money's on Occam siding with the lady
and the car being the complex device with many failure modes
But it could be the other way around

Trouble is you cant convict on best guess - or can you

[saaby93]

Durzel said:

I would presume that car software is written in such a way that if it fails then it's like a dead man's switch, in other words the software has to be operational (not crashed) for the car to (continue to) move at all.

If drive-by-wire was at risk of sticking open the throttle, or could actually crash in the traditional sense, we'd be hearing about it all of the time.

Why? It doesnt happen very often

[saaby93]

Roger Irrelevant said:

Why don't we see Qashqais (or other similarly complex machinery) careering out of control for unknown reasons on a regular basis?

This doesnt have to be a regular basis failure mode (they'd have fixed that) - isn't more likely a very rare occurrence failure mode?

[saaby93]

Wills2 said:

The absence of any explanation as to how the car could leap forward with no driver input means it's going to be difficult to create a reasonable doubt in the mind of the jurors as to what actually happened.

She hasnt said it was with no driver input - do some people not read the article

She said she pressed the accelerator lightly when the car surged forward - already some indication of a possible failure mode there
then when she pressed the brake little happened - which may not be surprising if the car's in full pelt mode
Its not the braking shes arguing about - its the going into full acceleration mode when touching the throttle

Once that's happened it's going to take you some seconds to get on the brake anyway

article said:

Mrs Diggles, who was attempting to park, said: "I went into drive and I put my foot very gently on the accelerator to cross the road and then the car just took off. It surged forward.

"I can remember taking my foot off the accelerator quickly and I'm sure it went on to the brake and the brake didn't appear to be working.

Unless Nissan can demonstrate they have a better fault control system than the space shuttle with its 13 computers ( because they didnt trust any one of them) surely there is reasonable doubt?

Edited by saaby93 on Friday 3rd February 14:28

[saaby93]

AJB said:

saaby93 said:

She hasnt said it was with no driver input - do some people not read the article

She said she pressed the accelerator lightly when the car surged forward - already some indication of a possible failure mode there
then when she pressed the brake little happened - which may not be surprising if the car's in full pelt mode

That would be VERY surprising. Instinct would mean she'd press the brake very hard, and brakes can easily resist the engine, even at full pelt. Indeed, testing torque converters can involve a stall-speed test where you floor the accelerator whilst standing hard on the brake pedal and see what revs are achieved. The car doesn't accelerate and crash when you do that.

Is it still a torque convertor?
Anyway as I said shes not arguing about the brakes - by the time youve thought about braking whatever it has already happened - its the accelerator surge. How would the engine know that was a fault rather than someone requesting max power?

Edited by saaby93 on Friday 3rd February 14:35

[saaby93]

GroundEffect said:

You should see the safety validation and FMEM handling with hardware redundancy it goes through. It boggles my mind, and I've been involved in it for years.

I could ask the same here
How would the engine know the difference between a faulty input from a light throttle press and a normal request for max power?
Surely as its within normal operating parameters it would just give max power?

[saaby93]

durbster said:

Have you ever heard of a case of "unintended acceleration" where the driver has pressed the brakes?

erm no
Ive heard of when youre being towed you have your foot over the brake then suddenly the tow car stops so you do the typically move your foot across and floor the clutch

also there's the brake hard merchants who floor the accelerator by mistake and light up the front wheels

This case is different for two reasons because
her first action is to lightly press the accelerator and the car surges forward - it takes off
- that's not the usual wrong pedal action described by other posters
It sounds like a fault in the fly by wire system somewhere

When it's done that she tries braking and find they don't seem to be working properly
- she doesnt say they're not working as some posters have tried to say
she's explaining the effect on the brakes that the initial fault is causing

And no - I wouldnt expect it to be easily recreatable - it's just one of things that might happen once in a blue moon with electronic gubbins

Edited by saaby93 on Friday 3rd February 15:37

[saaby93]

Silent1 said:

The brakes on any car in current use will absolutely stop that car even with the engine at full throttle, the stopping distance usually increases by 10 metres over a normal emergency stop. If there was a car in the road that couldn't stop then it's brakes would be so woefully inadequate in normal usage as to be dangerous.

Unless I'm misreading it can we stop going on about the brakes
I dont think shes claimed brake failure - only that they wouldnt working properly
The issue is with the other pedal - the car surging off

[saaby93]

AJB said:

saaby93 said:

Unless I'm misreading it can we stop going on about the brakes
I dont think shes claimed brake failure - only that they wouldnt working properly
The issue is with the other pedal - the car surging off

But if you're heading towards something or someone fast, then as long as your foot isn't on the wrong pedal every subconscious instinct will make you press the brake pedal really hard.

I don't think it's at all likely that the car surged, and she reacted by getting on the brakes but only pressed the pedal gently and crashed at speed.

To my mind either she was on the wrong pedal so didn't press the brakes hard, or the brakes didn't overcome the engine's torque despite her pressing hard. And that'd mean mechanical/hydraulic brake failure as well as throttle failure.

If she'd said "the car surged forwards so quickly that I didn't even have time to get to the brake pedal before crashing" then I'd be more inclined to accept that it could have been the car's fault (although human error is still MUCH more likely). But the fact that she thinks she's moved her foot to the brake pedal and pressed it, but couldn't slow/stop the car with the brakes, almost 100% rules out car problem in my mind.

She was trying to move off though - she pressed the throttle lightly and the car took off
There's no braking in that
I dunno - there seems to be enough doubt to me, lets see what the court comes up with?

[saaby93]

Venturist said:

Make a little cheapo camera looking down at the pedals standard equipment on every car.

End of all debate on the subject. Sorry, Mavis, you felt like you were pressing the brake but as you can see in this video actually you were pressing the accelerator. Rather hard.

Surprised Toyota aren't all over this after their legal drama.

yes - it could be useful for all sorts of things, it would need the exterior cam as well tho, and one on what the drivers doing upstairs

[saaby93]

SonicShadow said:

Klippie said:

These things do happen...my new at the time Scirocco TDi took off on its own I was in second gear doing no more than 20mph, next thing it was full throttle rev's off the counter thankfully there was nothing around, a seal blew on the turbo it was running flat out on its own engine oil till it ran out, I shudder to think if this had happened in traffic or at a pedestrian crossing.

In your case there was a very obvious failure that caused it to do that. In this case, there is nothing to suggest that, just the word of an 80yr old who is adamant that they didn't press the accelerator.

erm at what point did we stop taking the word of an 80 yr old?
If its the same type of random failure it doesnt matter what the age is of the driver
You cant say X didnt happen because someone was 80