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Why emergency braking systems sometimes hit parked cars and lane dividers

arstechnica.com

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Re: Why emergency braking systems sometimes hit parked cars and lane dividers

#2
This article and many others like it are written as if one ought to be ashamed for thinking self driving cars should not routinely smash into stationary objects on their paths or kill people:

    This isn't the only recent case where Autopilot steered
    a Tesla vehicle directly into a stationary
    object—though thankfully the others didn't get anyone
    killed. Back in January, firefighters in Culver City,
    California, said that a Tesla with Autopilot engaged
    had plowed into the back of a fire truck at 65mph. In
    an eerily similar incident last month, a Tesla Model S
    with Autopilot active crashed into a fire truck at
    60mph in the suburbs of Salt Lake City.

    A natural reaction to these incidents is to assume that
    there must be something seriously wrong with Tesla's
    Autopilot system. After all, you might expect that
    avoiding collisions with large, stationary objects like
    fire engines and concrete lane dividers would be one of
    the most basic functions of a car's automatic emergency
    braking technology.
Regardless of how they came to be, yes there is something seriously wrong with these systems.

Re: Why emergency braking systems sometimes hit parked cars and lane dividers

#3
post #2

This article and many others like it are written as if one ought to be ashamed for thinking self driving cars should not routinely smash into stationary objects on their paths or kill people: This isn't the only recent case where Autopilot steered a Tesla vehicle directly into a stationary object—though thankfully the others didn't get anyone killed. Back in January, firefighters in Culver City, California, said that…

I didn’t get that at all. It was written in a dispassionate tone but it didn’t blame the driver at any point.

Re: Why emergency braking systems sometimes hit parked cars and lane dividers

#4
This is a pretty good explanation of the shortcomings of today's assisted driving capabilities. The marketing towards 'self driving' or 'auto pilot' should really emphasize on these.

My guess here is that the lane assist and adaptive cruise systems somehow thought the car it was following switched one lane to the right, and so the Tesla assumed it was on the most left lane, without any moving car in front (hence accelerating back to 75mph). But what it thought was the most left lane was actually the space between an hov exit and the real most left lane.

What's amazing is that, prior to that article, I had no idea that collision avoiding system at high speed would ignore any stationary object, even if it's right in front of you... This changes dramatically how I'll perceive such assisted technology from now on.

Re: Why emergency braking systems sometimes hit parked cars and lane dividers

#5
post #2

This article and many others like it are written as if one ought to be ashamed for thinking self driving cars should not routinely smash into stationary objects on their paths or kill people: This isn't the only recent case where Autopilot steered a Tesla vehicle directly into a stationary object—though thankfully the others didn't get anyone killed. Back in January, firefighters in Culver City, California, said that…

Didn't hit me that way. Sounds more like we as consumers misinterpret what the technology is and trust it too much... of course, there's a feedback loop where companies like Tesla call everything autonomous and hype the marketing to mislead consumers.

Re: Why emergency braking systems sometimes hit parked cars and lane dividers

#6
If Tesla actually made Autopilot into an emergency braking (or, more generally, safety) system, it would be fine. All they’d have to do is make two changes: switch from automatic steering to a lane departure warning system (so the driver must keep their hands on the wheel and will always be paying attention) and possibly rename it.

Of course, their stock price might crash and a whole bunch of customers who paid for self-driving features might be seriously pissed.

Re: Why emergency braking systems sometimes hit parked cars and lane dividers

#7
The cost of false positives at freeway speeds is part of the reason:

> When a car is moving at low speeds, slamming on the brakes isn't a big risk. A car traveling at 20mph can afford to wait until an object is quite close before slamming on the brakes, making unnecessary stops unlikely. Short stopping distances also mean that a car slamming on the brakes at 20mph is unlikely to get rear-ended.

But the calculation changes for a car traveling at 70mph. In this case, preventing a crash requires slamming on the brakes while the car is still far away from a potential obstacle. That makes it more likely that the car will misunderstand the situation—for example, wrongly interpreting an object that's merely near the road as being in the road. Sudden braking at high speed can startle the driver, leading to erratic driving behavior. And it also creates a danger that the car behind won't stop in time, leading to a rear-end collision.

When training new human drivers, they're taught to to steer around obstacles at freeway speeds, instead of braking for them. This is partly because it can take too long to brake.

The other half is these are often separate modules calling each other.

> And like adaptive cruise control, automatic emergency braking is often implemented as a separate system from the lane-keeping module. Most AEB systems lack the kind of sophisticated situational awareness a fully self-driving system would have. That means it may not be able to tell if an object 100 meters ahead is in the current travel lane or the next lane over—and whether it's a temporarily stopped car, a pedestrian, or a bag of garbage.

The auto-braking system could be a basic distance sensor calling the drive-by-wire API with "FULL STOP". This would definitely be non-ideal for freeway situations and speeds.

"If you're at lower speeds, at 30mph, and it detects a stationary object, these systems will generally respond and slow the car down and bring it to a stop," Abuelsamid told us. "When closing speed is above about 50mph, if it sees a stationary car, it's going to ignore that."

Indeed, automated braking that can only apply 100% braking is not ideal at freeway speeds. Collision avoidance at that speed must depend more on steering than stopping, but systems in cars aren't integrated in a way that would allow them to create this level of awareness.

Re: Why emergency braking systems sometimes hit parked cars and lane dividers

#8
Until I read this article, I thought that the all-optical adaptive cruise control system of my BMW i3 was clearly inferior to modern radar-based gear. I now see at least one use case -- stationary objects -- where the i3 setup has an edge. (But the i3 setup suffers mightily in low-contrast and low-sun-angle scenarios.)

Re: Why emergency braking systems sometimes hit parked cars and lane dividers

#9
post #2

This article and many others like it are written as if one ought to be ashamed for thinking self driving cars should not routinely smash into stationary objects on their paths or kill people: This isn't the only recent case where Autopilot steered a Tesla vehicle directly into a stationary object—though thankfully the others didn't get anyone killed. Back in January, firefighters in Culver City, California, said that…

This is an odd claim to make, since the article doesn't say anything at all about self-driving cars. Moreover, I don't think it's trying to shame anyone. It's making the point that there is a difference between crashing due to an error in the driver assistance systems and crashing due to encountering a situation that the system is incapable of handling. The tail end of the article states unambiguously that this is not an acceptable state of affairs, and that the next generation of driver assistance systems needs to take a different approach.

As to whether this article is really a stealth advertisement for GM's Super Cruise technology, well... yeah, it probably is. But I still found it informative as to the current state of driver assistance systems. I was not aware that the cruise control, lane keeping, and automatic braking systems were generally completely independent of each other.

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