Another Tesla on autopilot steers towards a barrier • Hacker News Board

Re: Another Tesla on autopilot steers towards a barrier

#271

Post by Tloewald » Fri, Apr 06, 2018, 6:57 PM UTC

lisper wrote: post #232

Tloewald wrote: post #222

Earlier quoted context omitted.

> It's not possible to engineer an autonomous system that never fails, but it is possible to engineer one in such a way that it never fails to detect that it has failed This seems to me to be a clearly incorrect (and self-contradictory) claim. It entirely depends on your definition of failure. Your analysis seems fine. The big problem is that the "autonomous" driver is using one signal (where are the lines on the edg…

> This seems to me to be a clearly incorrect (and self-contradictory) claim. I guess that means I was able to pull the wool over the eyes of all five members of my thesis committee because none of them thought so. > It entirely depends on your definition of failure. Well, yeah, of course. So? There is some subset of states of the world that you label "failure". The guarantee is not that the system never enters one of…

Arguing that it's possible to build an autonomous that is sometimes wrong but always knows when it's wrong seems like a stretch to me.

Re: Another Tesla on autopilot steers towards a barrier

#272

Post by lifeformed » Fri, Apr 06, 2018, 7:16 PM UTC

walrus01 wrote: post #230

iainmerrick wrote: post #91

Earlier quoted context omitted.

Yikes! I really hope that's a joke...

I have seen pictures of iPads strapped to steering wheel in Nissan Altimas, so yes people are really this dumb. Airbag issues entirely aside.

Oh god. Imagine the last thing you see before dying is your candy crush score propelled at your face at 200 mph.

Re: Another Tesla on autopilot steers towards a barrier

#273

Post by nerpderp83 » Fri, Apr 06, 2018, 7:16 PM UTC

mynegation wrote: post #212

lisper wrote: post #122

Here is my armchair diagnosis: right before the car veers towards the barrier it drives through a stretch of road where the only visible lane marker is on the left. Then the right lane marker comes into view at about the point where the lane starts to widen out for the lane split. The lines that will become the right and left lane markers of the split left and right lanes respectively are right next to the van in fro…

That's probably right or very close to what is happening, but what I cannot understand: what about damn black-and-yellow barrier board right in front of the car closing in at the speed of 60mph? Some sensor should have picked up on that.

The cars will for survival should outweigh the lane marker following algorithm. Maintaining distance and trajectory relative to things with mass is more important than coloring within in the lines.

Re: Another Tesla on autopilot steers towards a barrier

#274

Post by ricardobeat » Fri, Apr 06, 2018, 7:17 PM UTC

Someone1234 wrote: post #240

lisper wrote: post #201

Earlier quoted context omitted.

> if a simple explanation exists, I'd love to hear it Basically it's a matter of having multiple redundant sensors and sounding the alarm if they don't all agree on what is going on, and also checking if what they think is going on is in the realm of reasonable possibility based on some a priori model (e.g. if suddenly all of your sensors tell you that you are 100 miles from where you were one second ago, that's prob…

That's exactly how a lot of commercial aircraft systems work, they have three, if two agree and one disagree then that one is ignored. But it is more complicated than that when you're talking about algorithms and complex systems. If you had three of the same exact system, they'd likely all make the same mistake and thus you'd gain no safety improvement (except actual malfunctions, not logical limitations). I would li…

This has been mentioned a lot of times lately (the auto-braking). When you think about it, you realize there are a million moments during normal driving where you have an obstacle ahead. Other cars, lane dividers like these that you might _have_ to pass by closely, or at least will have your car pointed at it for a few seconds, making tight curves on a walled road, high curbs, buildings that are on the edge of the road, etc. It's not that simple, and I bet a lot of this is already taken into account by the software.

Re: Another Tesla on autopilot steers towards a barrier

#275

Post by michaelt » Fri, Apr 06, 2018, 7:17 PM UTC

aws_ls wrote: post #196

jacquesm wrote: post #157

Earlier quoted context omitted.

I drive a lot with my GPS (TomTom) on and it rarely gets the lane I'm in wrong, usually that only happens in construction zones. So even if the error can be large in practice it often works very well. It would be very interesting to see the input data streams these self driving systems rely on in case of errors, and in the case of accidents there might even be a legal reason to obtain them (for liability purposes).

Is it using some other localization technique to complement the GPS? GPS at best can give accuracy within 3 meters (if I remember right). To make it accurate, laser/radar beams are shot out to the landmarks, of which precise co-ordinates are known, and using them the pin point coordinates of Ego vehicle are determined.

The highest resolution GPS receivers have two changes:

1. Base stations at known locations broadcast corrections for factors like the effects of the ionosphere and troposphere, and inaccurate satellite ephemerides. If you have multiple base stations, you can interpolate between them (Trimble VRS Now [1] does this, for example)

2. Precise measurements by combining code phase (~300m wavelength) and carrier phase on two frequencies (~20cm wavelength), plus the beat frequency of the two frequencies (~80cm)

With these combined, and good visibility of the sky, centimetre-level accuracy is possible.

Autonomous vehicles will often combine this with inertial measurement [2] which offers a faster data rate, and works in tunnels.

Many people also expect autonomous vehicles to also track lane markings, in combination with a detailed map to say whether lane markings are accurate.

[1] http://www.trimble.com/positioning-services/vrs-now [2] http://www.oxts.com/products/rt3000/

Re: Another Tesla on autopilot steers towards a barrier

#276

Post by nerpderp83 » Fri, Apr 06, 2018, 7:18 PM UTC

godshatter wrote: post #254

mynegation wrote: post #212

Earlier quoted context omitted.

That's probably right or very close to what is happening, but what I cannot understand: what about damn black-and-yellow barrier board right in front of the car closing in at the speed of 60mph? Some sensor should have picked up on that.

This was my thought as well. Doesn't the system have the equivalent of reflexes that override the approved plan? I've been skeptical of autonomous driving since it started to become a possibility. I spend a fair amount of time making corrections while driving that have nothing to do with what's happening in my immediate vicinity. If it can't handle an obstruction in the road, how will it handle sensing a collision do…

What is someone drives down the road with lane-marking painter? I have witnessed two or three times in my life, it used to just be funny, but now it can be deadly.

Re: Another Tesla on autopilot steers towards a barrier

#277

Post by dwighttk » Fri, Apr 06, 2018, 7:20 PM UTC

pjc50 wrote: post #118

iainmerrick wrote: post #91

Earlier quoted context omitted.

Yikes! I really hope that's a joke...

Proponents keep touting this as the real benefit of self-driving cars, so it's hardly surprising that some people have taken them at their word and not realised that the car is not, in fact, truly autonomous and may drop out at any moment.

or not drop out and drive you into a barrier

Re: Another Tesla on autopilot steers towards a barrier

#278

Post by planetjones » Fri, Apr 06, 2018, 7:24 PM UTC

Does anyone know how software updates are tested for such autonomous driving software ? Is there a possibility for this driver's video to be added to a regression suite and tested, or can they take the data from his car and build a regression test based on it ?

Re: Another Tesla on autopilot steers towards a barrier

#279

Post by 7952 » Fri, Apr 06, 2018, 7:26 PM UTC

rectang wrote: post #89

The ability to discern when the car needs to stop for a stationary object right in front of it needs to be an ironclad requirement for self-driving. It seems that sophisticated LIDAR is currently the best way to achieve this, but LIDAR is expensive. So companies like Uber and Tesla skimp on the LIDAR, and build self-driving cars that can more or less follow lanes but plow right into obstacles ? Whoa. The feasibility…

I wonder why they can't just use a less sophisticated lidar. Just have a few fixed beams that just look ahead. Do you really need a scanning system to detect an obstruction?

Re: Another Tesla on autopilot steers towards a barrier

#280

Post by mhermher » Fri, Apr 06, 2018, 7:30 PM UTC

DSingularity wrote: post #182

dancek wrote: post #165

Earlier quoted context omitted.

> It's not possible to engineer an autonomous system that never fails, but it is possible to engineer one in such a way that it never fails to detect that it has failed. This is a very good point: just like a human driver should slow down if they can't observe the road ahead well enough, an AI should slow down when it's not confident enough of its surroundings. This is probably very difficult to do, and I'm skeptical…

I feel that’s the problem. Techniques like SVM can provide reasonable definitions of confidence. Reinforcement Learning.. DNN... the mechanisms behind autonomous cars... are they able to do this??

not an expert, but aren't the output nodes thresholded to make a decision? How far you are from the threshold might be interpretable as confidence possibly?