Hacker News Reader

Comment by shiftpgdn | Hacker News Reader

Toyota accelerator-gate is largely a farce. Almost all of the people involved with Toyota unintended acceleration were over the age of 65 and had the poorly designed loose floor mats in their cars.

Even if they had perfect readable John Carmack tier coding they still would have lost.

View on HN

Sure but that's not related to the point I'm making. The point is that not following software design best practices can leave you open to liability, or at least put you in such a weak legal position that you are compelled to settle.

If/when Tesla gets hauled into court over its software flaws, any lack of adherence to best practices will make the company appear negligent.

This is a risk adverse culture then. Tesla is spending gobs of money specifically on building safer if not the safest cars out there.

How do you square that with them removing sensors from their cars and going all-in on doing self-driving exclusively using vision? If they were so passionate about spending money to make the safest cars, they'd be doing sensor fusion.

> If they were so passionate about spending money to make the safest cars, they'd be doing sensor fusion.

That's your opinion. They have shown data where the information from radar was of a lower quality than what their vision stack was providing (e.g. lack of vertical resolution). Watch their AI day webcast for examples. Their current vision-only stack has been validated with LIDAR ground-truth data.

Is anyone arguing for replacing vision with lidar and radar instead of combining it?

If the radar data conflicts with what vision is saying, which one do they trust? They have shown that their vision stack has surpassed what they can do with radar. So "fusing" that data in only makes it worse when it gives conflicting information.

Sensors are obviously important, but it doesn't really matter if two sensors conflict, the important thing is which one is consistent with their running model.

So far their biggest problem is that they allow flicker. That's why sometimes the software picks the wrong lines. (Of course this is a very hard problem. Our brain conveniently smooths over sensory changes for us, because that's how our everyday reality is. Things don't flicker in and out of existence, nor does a car suddenly appear as a different thing, then switches back.)

And if it turns out the sensor(s) failed, it has to be able to handle that too.

> building safer if not the safest cars out there

Unless the car loses power and catches fire. Then you can't open the fucking doors [0].

[0] https://www.washingtonpost.com/business/2019/10/23/man-died-...

Using 1 off cases based on unsubstantiated information in a lawsuit is not a persuasive argument for overall safety.

It's certainly a better argument than the GPs claim of "the safest cars out there" with 0 evidence given to substantiate that. I think it fair to refute such an unsubstantiated claim with a reported instance where safety was not maintained as can reasonably be expected.

Tesla cars have the highest safety ratings in the world and they have the the best active safety features and complete fleet compliance with their whole fleet for new standard of active safety features (literally the only company that does have that).

This is literally just the basic fact of the situation. If you want to disagree with literally every state safety agency in the world, then you are the one who needs to come up with real evidence.

I worked for ford many years ago and I remember a really funny conversation between young engineers and MBA types. The issue was the Lincoln Towncar was designed to have extremely low pedal pressure because that is what the old buyers liked. Combine old people with limited hearing, no pedal pressure, and a quiet cabin it was a perfect recipe for old people to shift and send the car through the garage wall. Lol. The classic issue of when customers want something stupid, do you build it?

Not entirely a farce.

The PCM (engine controller) that a university audit got access to had 12,000 global variables. Their conclusion was it was not possible to prove either way.

There was a definitely real issue with floor mats getting the pedal stuck. I don’t know enough background on it past the audit that was done.

Easy to do. I stepped on the accelerator instead of the brake once. First impulse is to step harder, until you realize what’s going on. If your realization is slow, bad things can happen.

If bad things happen, the tendency is to blame someone else.

One solid step on the accelerator easily let's bad things happen below 1s.

I followed the accelerator-gate thing fairly closely, and I came out pretty convinced it was a computer failure. If it wasn't Toyota's floor mats were many times more likely to jam the accelerator than any other make or model.

There was a plausible root cause - a bit flip in the CPU. It was proved such flipping the right bit would cause uncontrolled acceleration that characterised each event.

I don't agree Toyota was guilty of shoddy work, or cost cutting. At worst, there were guilty of working some fairly shitty, hard to support code. (Someone below mentions 10,000 global variables.) If anything that shitty code just proves how dedicated Toyota was to testing something until until all the safety related bugs are gone, because despite some horrid kludges like replying on watch dogs resetting the thing when it got stuck and a reset so fast most people wouldn't notice it, despite the intense scrutiny of the code no one every found a safety issue with it. Toyota was well aware of a electrically noisy area like a engine bay could cause bit lips, and defended against it. Every variable was stored in two places in RAM, and on use they were always read and compared, and if they differed it was reset.

Sadly for Toyota they used a proprietary ECU and OS provided by NEC. NEC didn't let their customers look at their proprietary stuff. NEC didn't defend against bit flips. And it turned out a bit flop in a task ready bit could cause that task to never be scheduled again. If that task was supposed to turn off the cruise control acceleration, then bingo.

I have no idea what changes Toyota made in response to this mess, but if I was to hazard a guess it would be when it comes to software, they demand their supplies open their source to them.

The pedals are close together in my car, and a couple times I have hit the accelerator rather than the break. But I knew immediately what was wrong and adjusted.

It literally took me years to understand it - how can you accelerate by accident? Until someone mentioned that all of these cars were automatics.

But every automatic I've ever driven (not many - I prefer a clutch) moves forward unless you're pushing the break in. In the rest state, it's in motion.

The problem isn't Toyota, the problem is a broken system.

That's a mechanical side effect of the torque converter used in automatics, which even at engine idle with no acceleration input is able to transfer power to the drivetrain.

The Toyota case was an instance of the car's engine control software unexpectedly commanding acceleration not requested by the user.

In principle it could happen on a manual car as well, but most of Toyota's vehicles in the U.S. are automatics.

People panic and jam the wrong (or both) pedals. (There are quite a few people who use two feet to drive automatics, one foot for break, other for gas..)

> There are quite a few people who use two feet to drive automatics

They are very irritating to drive behind. Some seem to keep pressure on the brake pedal, and the brake lights stay on as they accelerate. When they slow it takes longer to realise they are braking as the lights have been solidly on.

Are you sure they're not just driving a manual transmission car? I can keep my foot lightly on the brake and apply the clutch to accelerate, without touching the accelerator pedal (diesel engine has a lot of low-end torque). Not that I do this in practice, except in drive-through lines just for the fun of it.

In first gear I can reach 8 km/h, but it's possible to get all the way to fifth gear while idling (takes a long time though).

I thought you would fail most driving tests doing that.

Perhaps, but left-foot braking is a useful technique, and common practice in some forms of racing.

In street driving, the main application is being ready to brake while driving normally. It is much faster to brake with the left foot hovering over the brake pedal than by moving the right foot from the throttle to the brake. Of course covering the brake pedal with the right foot precludes driving normally on a flat road or uphill.

This should of course be practiced in low-risk situations before being attempted in high-risk situations.

True but these are definitely not race drivers I'm seeing, jumpy older drivers mostly.

Not sure how is this possible. Automatic cars almost always require You to push brake constantly if you not driving. You can't turn car on without pressing brake, can't change to drive mode from parking state without pressing brake. There should be something very broken in Toyota case.

Automatic handbreak at a traffic light?

Reply on news.ycombinator.com