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Self Driving Uber Fatality - Thread IV 7

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All cars and light trucks (and probably heavy on-road trucks) destined for the developed world since 1996 have used drive-by-wire for the accelerator/throttle due to OBDII emission and diagnostic requirements.

ABS has been mandatory for quite a while. "reduce the brake pressure to unlock the brakes" and "merely pulsing the brakes" - pulsing the brakes is done by reducing the brake pressure. Perhaps what you mean is that some systems are capable of modulating brake pressure as opposed to cycling between driver-request brake pressure and zero.

Stability-program has also been mandatory in the US market for several years now. In order to do that, the brake systems have to be able to actuate brakes independently of whether the driver is requesting brake actuation. So, all modern automotive ABS systems are capable of not only reducing brake pressure but also applying it when the driver isn't.

"Electronic differential lock" piggybacks on top of this. If you have drive-by-wire and you have ABS with actuators, then traction and stability control and EDL and all sorts of drive modes that 4x4 vehicles use are just software.

I accept power steering but I draw the line at the computer deciding to turn the steering wheel. That's a decision that I want to reserve for myself. I don't want any part of the newfangled self-driving systems. Traction control doesn't trouble me but I want to be able to turn it off. It seems that "the powers that be" have decided that ABS systems shall not be capable of being turned off.
 
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That's correct, the 'off' button typically means 'less intrusive', many of the functions are still enabled. TC is probably the only one that can be completely deactivated, and ABS in snow mode, if you have it, is not going to intervene. You cannot buy a new car in the USA that doesn't have ESC and ABS, since 2012. Anything with a high cg will have Roll Over Mitigation, in practice.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
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I'll preface this by stating wholeheartedly that I think fully autonomous vehicles (outside of controlled or purpose built environments) are a long way off if ever. And that they should not be beta tested on public roads without strict regulatory oversight. But those citing one case of a flipped bit gremlin or who are otherwise fearing the infernal ECU are acting as if throttles have never hung open in the history of mechanical linkages to butterfly valves.

As for stability and traction control... I have definitely felt the former help when having to take sudden evasive maneuvers on wet pavement. Why wouldn't I want that feature? Or traction control for that matter? I grew up in the land of lake effect snow without it and know how to horse a FWD sled around in all kinds of conditions so I can moderate a throttle just fine if I have to. And I do. But it's also great when I'm sitting right on that patch of ice and the light and TC takes care of it for me. What's the harm?

I've got adaptive cruise at the moment and it's wonderful. And I recently drove a '19 Nissan Rogue with an even better system. It would bring the vehicle to a complete stop and resume it as needed. Really cuts down on fatigue during long trips in traffic.

It had "lane keep(?)" assist system too that would subtlety keep the car between the lines as needed. It was very well implemented and could tell quite readily if I was an active participant in steering or not and would disable if I wasn't. And while it could steer the car, I got the sense that it was very limited in what it could do in the event of a malfunction. For one, it was just a torque assist unit to an otherwise mechanical system. It is there to provide a modest amount of torque and I presume it wouldn't be capable of more than that. Why would it be? So if it ever wanted to do something I didn't want it to, I would be able to manage to overpower it. It also appeared limited in its speed. It's just there for subtle course corrections. You folks act as if somehow this thing is going to wrest the wheel from your hands and turn it to the left full lock into oncoming traffic in the blink of an eye.

You know what's much more likely to kill you? Some mechanical failure (ball joint, tie-rod end, frame, braking system) of a rust bucket an eastbound jalopy that sends it careering into your westbound lane under no control whatsoever because we don't have a mandatory nationwide vehicle safety inspection program.
 
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fwiw: I don't know when electronic throttle became 'mandatory', but for sure GM's 2003 Buick Regal did not have it. I think they went to dbw in 2004.
But the electric power steering? It has the torque to steer a car when stationary, when you would have difficulty steering it unassisted.
Therefore, it may indeed have enough torque to overpower a person, depending on that person's muscularity or alertness.


Jay Maechtlen
 
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My 2002 Kia Sedona has mechanical throttle linkage, as does my 1997 Nissan pickup.

Rod Smith, P.E., The artist formerly known as HotRod10
 
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Drive-by-wire throttle is not "mandatory", still isn't to this day, but it is really hard to achieve current emissions targets without it. And it's hard for stability control systems to work properly without it.
 
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Oh I checked on my 2018 SUV with EPAS and more electronics than it needs. Both brakes and steering work normally if I switch the engine off (push start button for 3 seconds) at 40 mph. I don't know if the brakes were working on the vacuum reservoir or the ABS pump. Irritatingly it won't restart until the trans is in Park. Grr.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
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GregLocock said:
I don't know if the brakes were working on the vacuum reservoir or the ABS pump.
Click to expand...
If you were at speed and in gear then you would still be getting vacuum from the still turning engine.

GregLocock said:
Irritatingly it won't restart until the trans is in Park.
Click to expand...
Did you try neutral? Certainly my car from the mid 90s could be restarted in neutral. I had to do that a couple of times when my duel fuel LPG switch stopped the engine briefly.

 
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BridgeSmith - I hope you're not expecting to buy a new vehicle then. EVERY newer car built for North America is electronic throttle and they all have stability control systems that can apply the brakes. I'm actually surprised you found a 2009 model with a throttle cable. That was definitely the last of a dying breed. As already noted, the electronic throttle still isn't mandatory, but it's was made necessary for emissions and for the mandatory stability control system which was made mandatory in 2012 in the USA. Your thoughts on simple ABS pulsing systems might apply to early systems from the 80's or early 90's, but that's about the only time range where they might have existed. All manufacturers have used systems with 4 wheel speed sensors for many years now.
 
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As for Toyota. I never did hear a definitive cause behind those true stuck throttle cases. I know they found tin whiskers growing in the throttle pedal that could cause the wrong signal to be sent to the ECU which could cause the throttle to open. They also found that the ECU code was crap for lack of a better description. The ECU code supposedly could only cause the throttle to hang at the last cruise control commanded level and not force it open wider. Lots of complaints also consisted of "The car surged ahead when I stepped on the brake" which makes me believe many of the complaints were simply cause by the owner catching the throttle pedal with the edge of their foot as they stepped on the brake
 
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LionelHutz, I didn't say I wouldn't buy a car with an electronic throttle. 3 of my cars do have them (btw, it was a 2002 model that I said had a mechanical throttle, not a 2009). The electronic throttles have a good history of reliability, and as the posted story showed, managing to control the vehicle if it does malfunction is generally not difficult, especially if a person drives cautiously (not tailgating, etc.), as I do. I drove enough old clunkers in my younger days, I still leave myself enough of a space cushion from other vehicles to account for brakes failing (or sudden acceleration) or the engine dying instead of accelerating from a stop.

What I will attempt to avoid, at least until there is a much larger history of success, it vehicles where the computer can move the steering wheel or apply the brakes to individual wheels.

Rod Smith, P.E., The artist formerly known as HotRod10
 
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So nothing newer than 2012, then, and nothing with stability-control (which started several years before that). That's when stability-control became mandatory in the USA. All automotive stability-control systems rely on being able to actuate brakes on individual wheels independently of driver input. All of the current ones that have an "off" button, don't really turn completely off when that button is pressed, either. (Some of them have a special procedure to go through which they claim turns it off, but I suspect it just de-fangs the system to the bare minimum that can pass the legal requirements.)

Self-steering is where I draw the line. I don't want anything to do with that.
 
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AFAIK the only cause was using oversized mats on one car. The first driver to encounter the dealer loaner got that car to the side of the road and discovered the problem, returned to the dealership and complained. They did nothing and sent the car out in the same condition, where that driver crashed. The dealer was sued out of existence. In either case the driver had to have pushed the pedal literally to the floor for the pedal to catch the floor mat.

The tin whisker problem was a different symptom where the throttle would be unresponsive for the initial part of the travel and then register as the pedal exceeded a relatively low threshold. The abrupt change in throttle response startled some drivers who mistook it for surging.

The only demo I ever saw was someone wadding a floor mat and jamming it alongside the accelerator pedal. With tens of millions of cars and tens of millions of cell phones the lack of video documentation suggests that there was no fundamental problem.
 
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And yet, since then, nothing about unintended Toyota acceleration**. The lawsuit failed to prove the software failed; it merely established that it might have. In a civil suit that's all that is required. The larger suit was for loss of value of the cars due to the adverse publicity that was supposed to be based on some demonstrated defect.

Our Toyota got the accelerator pedal recall, but I don't remember one to replace the ECM with a new fault-tolerant one.

Latest news -
**Except the guy who tried a hoax to get paid.
 
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human909 said:
If you were at speed and in gear then you would still be getting vacuum from the still turning engine.

Quote (GregLocock)
Irritatingly it won't restart until the trans is in Park.
Did you try neutral? Certainly my car from the mid 90s could be restarted in neutral. I had to do that a couple of times when my duel fuel LPG switch stopped the engine briefly.
Click to expand...

It's an auto so when the engine is stopped it doesn't rotate. Yes, interestingly despite the infobox on the dash, it will start from neutral.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
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GrekLocock said:
It's an auto so when the engine is stopped it doesn't rotate.
Click to expand...
If the car is still in gear the an engine on a auto will still get driven by the wheels. The torque converter will still transfer some rotation. But depends on whether you car lets you stay in gear. Older autos you could still roll start. Most autos in the last 20-30 years will let the wheels drive the engine and switch off all fuel when you coast at moderate speeds.

GrekLocock said:
Yes, interestingly despite the infobox on the dash, it will start from neutral.
Click to expand...
Its a good safety. I would hope it is on most if not all cars, but who knows with everything electronically controlled now.
 
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hpaircraft said:
So now they're just straight up equipping each car with a bone saw?
Click to expand...

Extreme point miss and a ridiculously stretched either/or proposition.
I suggest you follow the (real) news and catch up on what Uber have been up to.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."
 
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