Another unexplained acceleration

[FurtiveFreddy]

yellowjack said:

Anyone got a link to that track day/driving experience video?

The one where the instructor is yelling "Brake! Brake! ...BRAAAAKE!!!" and the chap driving it is yelling back "I am, I am, I am" as they leave the track and drive at high speed over the grass at the side of the circuit.

The bloke driving is absolutely convinced that he's braking, even though he's clearly hard on the throttle and the poor bloke beside him is begging him to use the brakes...

No, but I've got this one...

https://www.youtube.com/watch?v=QuotmQy4r4E

[RobM77]

GroundEffect said:

RobM77 said:

GroundEffect said:

RobM77 said:

GroundEffect said:

RobM77 said:

GroundEffect said:

saaby93 said:

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?

Hardware redundancy and check sum plausibility. As I said, the smartest people in the business have spent 20 years writing software and standards for this stuff. Don't underestimate it.

's ability to annoy the hell out of anyone used to driving a cable throttle car.

Just added a bit for you there

I defy any human to actually be able to tell the difference in 'time to torque' of fly by wire vs cable in a blind test. Compared to inertia of the engine and the combustion delays, it's negligible.

That's a very specific thing that you've chosen because it's hard to spot. There are plenty of other DBW characteristics that are obvious in many current production cars, such as the much written about lag at the top of the pedal - BMW especially can't get this right and most of their petrol engines are dreadful because of it (it's why I drive a diesel). With my E46 330ci you could count to three before the throttle pedal did anything - in fact I could tap my foot to the music in the car and the car would just serenely continue without any modification to torque supplied at all. Then there's the three effects I listed in my post earlier on - those are pretty scary. You've also got the weird relationship between throttle pedal position and torque, rather than what you get with a cable, which is throttle pedal position and throttle opening on the engine (as I'm sure you know, at low revs a small throttle opening can deliver more torque than a large one, DBW manages this for you, meaning the pedal is a torque request lever, not a throttle opening lever).

Don't get me wrong, DBW is a great technology. In my 2-Eleven it was fantastic and a noticeable improvement over my Elise 111S. I've not driven a single seater with DBW, but I should image they're good too (otherwise they'd be undriveable). In most fully homologated production cars though, especially petrol powered ones, it's utter st.

Then it's kind of down to driver preference, right? Because I design the pesky things, I do think of the throttle as a 'torque demand' not a 'butterfly valve position control'. So I adjust my own inputs to suit.

I haven't worked on Driver demand control (the wky term we use in the industry) directly but I presume there is a reasonable amount of damping in the system at the first few %age of travel to keep things smoother. My M3 in normal pedal map has that very thing. It makes causing backfires more bothersome!

The other aspects that I listed (delays etc) are just bloody annoying - I've lost count of the number of otherwise superb cars ruined by effects like that. For example, the problem with top of pedal lag is mainly in entering a corner; if a car takes half a second to respond when you transition from brake to throttle then that may not seem a lot on paper, but in a 50mph corner that's 11.1 metres, which is the entire corner with no throttle control at all.

I'd be very surprised if the delay was actually 0.5 seconds. Time to torque on the engine itself will be around 0.3 seconds, of that maybe 0.05 will be electronic/actuator delay. I would be very interested in seeing data you have to show otherwise.

I was actually partly jesting and giving you the benefit of the doubt - I'm sure the delay on most modern cars is at least that.

As I said above on this thread, with my E46 330ci I could count to three before the engine responded, which surely can't be done in 0.5 sec. I could also tap my foot to music and have nothing happen, and if the music was typical radio pop at 120bpm, funnily enough that makes it at least 0.5 sec... My friend and I did once film it in my E46 330ci to measure the delay because I spent £600 with a company who said they could remove it. We measured it at just over a second. Things have got a huge amount better over the years, but it still ruins most petrol powered cars.

Next time I hire a car I can video it if you like. The last time we had a thread like this I owned a Z4 Coupé with a tiny delay and filmed it for a doubter, but even that tiny delay was very visible on the video. It was one of the reasons I sold the car actually. You can find the video on You Tube if you search - it's quite clearly visible, although small on that model of car (the reason I bought it).

Edited by RobM77 on Friday 3rd February 16:49

[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?

[FurtiveFreddy]

saaby93 said:

She was trying to move off though - she pressed the throttle lightly and the car took off

That's what she said happened. That's not necessarily what actually happened.

She also said "Then I saw this lady. I think she had her back to me and it just wouldn't stop before I got to her."

So she was absolutely certain which pedal was which, but she can't be sure which way the person she hit was standing?

[speedking31]

GroundEffect said:

... the smartest people in the business have spent 20 years writing software and standards for this stuff. Don't underestimate it.

A suggestion: If the throttle pedal is depressed quickly to 100% don't allow any power. (Or make 98-100% a dead zone.) How often does anyone except a racing driver actually need WOT? In a powerful car you are better off gradually increasing the throttle. That would prevent the accidental surge caused by stamping on the wrong pedal.

To appease the driving gods, it could be programmed into 'old folk' mode, or alternatively overridden by engaging 'Sport' mode.

I am sure that such a restriction would reduce this type of incident significantly.

[Jimmy Recard]

FurtiveFreddy said:

That's what she said happened. That's not necessarily what actually happened.

She also said "Then I saw this lady. I think she had her back to me and it just wouldn't stop before I got to her."

So she was absolutely certain which pedal was which, but she can't be sure which way the person she hit was standing?

She believes that she didn't hit the accelerator pedal hard but clearly she did. There is no doubt that she made an unfortunate mistake

Mistake or not, it happened. What's a suitable charge? Manslaughter?

[Venturist]

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.

[FurtiveFreddy]

Manslaughter would seem appropriate. Assuming there was no malfunction, her actions were the cause of the death.

Strange how these 'unintended acceleration' cases seem to almost always happen during parking.

There's a lawsuit a Korean celebrity is bringing against Tesla because his Model X 'drove itself into his living room' when we has trying to park it in his garage. Teslas have data logging and despite the logs proving that the accelerator was fully depressed when the car crashed through his living room wall, he is still trying to pin the blame on the car.

These people convince themselves they are not to blame and they may genuinely be sure in their own minds they were in proper control of their vehicles. It's a shame it needs a Court and expensive lawyers to get involved.

[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

[yellowjack]

Jimmy Recard said:

She believes that she didn't hit the accelerator pedal hard but clearly she did. There is no doubt that she made an unfortunate mistake

Mistake or not, it happened. What's a suitable charge? Manslaughter?

Causing death by careless driving.

She did not intend to kill the pedestrian. It seems to be accepted that she did not intend to even hit the pedestrian.

Manslaughter, like murder, requires a deliberate act. Unlike murder, though, the act is not intended to take a life. A manslaughter defence to causing a death would be along the lines of someone landing a deadly punch in a bar fight. "I intended to hit him, but not to kill him".

As far as I'm aware, there is no charge of "vehicular manslaughter" in the UK. Perhaps there ought to be, although I doubt it would be appropriate in this case anyway...


...many drivers have done what I would consider to be worse than this pensioner. A lot of them have got away with it. This is just a sad case of a pensioner clinging too hard to their car as a means to be independent, and someone has paid the price for it. She should be subject to a full medical, and if there's even the slightest doubt as to her fitness to drive, her licence should be revoked forever. If she passes the medical, a lengthy ban would be in order, but I suspect she might take herself off the road anyway, whatever the outcome of this case. No matter what the verdict, or the sentence if she's found guilty, there will be no winners in this instance. Maybe if enough oldies see reports of the case though, one or two of them might have a rare moment of clarity and admit that driving is something they should give up on at last.

My wife's grandad drove on well into his nineties. Being a passenger in his car was frequently a truly terrifying experience. He once pulled out of a lay-by into the path of a National Express coach. I've no idea how I'm alive to tell the tale, but I'm grateful for the coach driver's quick reaction. I doubt his passengers were though! 'Grandad' didn't even notice. He just continued his part of the conversation as me and my wife sat silent in the back, white as sheets and completely speechless. I've never been so glad to hear that someone has stopped driving as I was when he did.

[speedking31]

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.

Tape.

[Jimmy Recard]

That's it! I knew that manslaughter wasn't right but couldn't think of the right charge

[Silent1]

saaby93 said:

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

Im specifically countering mk2driver's assertion that there are cars with brakes that aren't strong enough to stop them at full throttle, nothing about this incident.

[HustleRussell]

FurtiveFreddy said:

Strange how these 'unintended acceleration' cases seem to almost always happen during parking.

People who are st at parking generally spend a lot of time parking.

[J4CKO]

Sometimes folk seem to have all the control over a car as a seventies entertainer did over a fake, large, flightless bird, just even less amusing !

[Markbarry1977]

J4CKO said:

Markbarry1977 said:

My gut instinct is that the dear old lady has probably by the law of averages got the wrong pedal but firmly believes she hasn't.

Having said that, how many times have I had to restart a pic or iPhone.

I get that it is all electronics but a DBW throttle has just one job to do, doesnt run an operating system, it cant really be user altered (apart from drive modes) as it has no connection to the outside world, PC's are millions of lines of codes to suit a multitude of different hardware and configurations, you can connect anything to it and to be fair, nowadays they work pretty well, not had to reboot my new one, built last year at at all.

The DBW throttle will be less code than a Nokia 3310 even, its a very simple system despite being electronic, not saying ti cant go wrong, EMF or the sensor breaks but like someone mentioned it is what it does in that scenario, suspect they default to a failsafe but if it thinks its got full throttle it will apply full throttle.

Grannies are more complex again than PC's and cant be patched

Yep I agree in principle, the dbw throttle only has one job, but the computer using the inputs from the Dow throttle will have millions of lines of code and do thousands of jobs. It only requires one coding error out of millions of lines of code and a certain scenario to result in the unexpected.

I still believe she got the wrong peddle.

[Mercury00]

French car in dodgy electric shocker

Or

Old codger presses wrong pedal shocker?

[Wills2]

FurtiveFreddy said:

yellowjack said:

Anyone got a link to that track day/driving experience video?

The one where the instructor is yelling "Brake! Brake! ...BRAAAAKE!!!" and the chap driving it is yelling back "I am, I am, I am" as they leave the track and drive at high speed over the grass at the side of the circuit.

The bloke driving is absolutely convinced that he's braking, even though he's clearly hard on the throttle and the poor bloke beside him is begging him to use the brakes...

No, but I've got this one...

https://www.youtube.com/watch?v=QuotmQy4r4E

Enjoy!

https://www.youtube.com/watch?v=Y4ZmolZCnX8

[RobM77]

Wills2 said:

FurtiveFreddy said:

yellowjack said:

Anyone got a link to that track day/driving experience video?

The one where the instructor is yelling "Brake! Brake! ...BRAAAAKE!!!" and the chap driving it is yelling back "I am, I am, I am" as they leave the track and drive at high speed over the grass at the side of the circuit.

The bloke driving is absolutely convinced that he's braking, even though he's clearly hard on the throttle and the poor bloke beside him is begging him to use the brakes...

No, but I've got this one...

https://www.youtube.com/watch?v=QuotmQy4r4E

Enjoy!

https://www.youtube.com/watch?v=Y4ZmolZCnX8

I'm torn between two reactions:

[hora]

People of all ages (with any money)will pay Solicitors to get them off a charge.

I don't see how this is any different.

My mapped Saab would surge forward but that's because I press the throttle firmly. Funny that.