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?

[SirSquidalot]

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

[t400ble]

Shes pressed the wrong pedal, simple as that

[GroundEffect]

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

Also I'm not going to take the word of a 82yo, sorry.

[TheInternet]

GroundEffect said:

Because it allows a lot of extra emissions control and render the response dog st.

Edited to reflect my experiences.

[Phil Dicky]

t400ble said:

Shes pressed the wrong pedal, simple as that

This ^^^^^

[crankedup]

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

Also I'm not going to take the word of a 82yo, sorry.

Indeed, with all this techno one might think that the use of a 'black box' would be simple and inexpensive.

[donkmeister]

Overall, which is a) more reliable and b) has the safer failure mode?

Also, why do throttle systems of all types have a vastly increased rate of dangerous failure when in close proximity to octogenarian ladies? Is there an ingredient in werthers originals that messes with the system?

[OverSteery]

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.

[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

[OverSteery]

saaby93 said:

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

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 and this sounds like rumor and rubbish. error handling, recovery and detection are part of safety critical system testing.

[TheInternet]

saaby93 said:

all the checking procedures had been based on a working system - they hadnt allowed for what happens when it had gone into lala mode

Safety critical custard. I'd also wager that there are fewer DBW incidents than cable throttle incidents.

[J4CKO]

Of course a conventional throttle never had a frayed cable and stuck open ? I must admit I am pretty conformable with the electronic throttle, though I avoid walking in front of older Maseratis with them....

It is very easy to be ageist and there are so many threads that treat older people as "Gimmers, "Giffers", "Duffers", "Codgers" etc that I find distasteful, however, it has to be acknowledged, respectfully that sometimes age catches up with people, plenty of younger people are crap drivers but you get to a certain age and your reactions slow down, you get various ailments and potentially end up on medication that can affect your motor skills.

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.

[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

[OverSteery]

TheInternet said:

saaby93 said:

all the checking procedures had been based on a working system - they hadnt allowed for what happens when it had gone into lala mode

Safety critical custard. I'd also wager that there are fewer DBW incidents than cable throttle incidents.

I certainly insist that any jet I fly on has good old cables running to each jet engine, and no newfangled electronic handbrakes either

[Mr2Mike]

OverSteery said:

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.

Do modern ECU perform continuous logging to NV memory? I thought only error conditions would cause that, and only if detected.

[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

[essayer]

I guess all she needs to do is introduce reasonable doubt into the equation and she won't be found guilty.

[OverSteery]

Mr2Mike said:

OverSteery said:

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.

Do modern ECU perform continuous logging to NV memory? I thought only error conditions would cause that, and only if detected.

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, otherwise data from many accidents would be lost, which is surely when its more needed.