How Google's Self-Driving Car Works • Hacker News Board

Re: How Google's Self-Driving Car Works

#51

Post by excuse-me » Tue, May 08, 2012, 4:05 PM UTC

daenz wrote: post #27

joezydeco wrote: post #25

Earlier quoted context omitted.

Not to speak like a party-pooper, but could someone potentially mess with this LIDAR system by aiming a very bright IR beam at the device, if not a matching laser itself? Bringing down the cost of the LIDAR will be one major task, the other will be making this untouchable in the environment, IMO.

> Not to speak like a party-pooper, but could someone potentially mess with this LIDAR system by aiming a very bright IR beam at the device, if not a matching laser itself? You could probably screw up the samples that would be taken from wherever your beam hits on the mirrors. But you could also shine a laser in someones eyes while they're driving and seriously impair them as well.

The Lidar is really only a convenient system for the prototype - production units would rely mostly on imaging and limited range radar for parking / collision.

Having said that - there is no real difficulty in making Lidar very cheap if you wanted to - it's all solid state

Re: How Google's Self-Driving Car Works

#52

Post by pilgrim689 » Tue, May 08, 2012, 4:06 PM UTC

omegant wrote: post #14

It is normal for pedestrians to look for eye contact in order to know if a driver will yield the right of way or simply will accelerate and pass (in light less crosswalks). In dense pedestrian cities (I am from Spain) it is very usual to have some guessing and false start stop between the pedestrian and the driver, nobody seems to know who is going to yield finally. I wonder if this is been thought and how you'll sig…

It makes sense for the self-driving car to yield to pedestrians all the time. So if you see that there is no driver, you assume it will stop until you are out of its way.

There will be no more awkward social guessing games!

Re: How Google's Self-Driving Car Works

#53

Post by xxbondsxx » Tue, May 08, 2012, 4:07 PM UTC

daenz wrote: post #47

xxbondsxx wrote: post #43

Earlier quoted context omitted.

LIDAR works _through_ reflections. It essentially paints out the surrounding area with laser pulses and then measures the time for those pulses to come back. Since lasers travel at the speed of light, this time-to-return is quite small and hence they need quite accurate clocks (which is where a lot of the expense comes in). That being said, laser range-finding works well on diffuse surfaces; this is because when diff…

I guess what I meant was, surely there are weird surfaces that have multiple bounces. Or light being emitted could bounce between 2 cars and back to the sensor...or off a shop window (at a high angle, fresnel reflection), back onto something else, and back into the sensor. This data would come back into the sensor and it wouldn't be expected. So surely the automated car, when it sees data it does not expect, does not…

Sure, the situation you described certainly happens and is just considered a general noisy measurement. The car could detect empty road one second and all of the sudden some small object _right_ in front of the grill at the next frame. To avoid this "freakout" situation where the car slams on the brakes every time a noisy measurement comes in, all the data is passed through a particle filter (or Kalman filter) first before being processed by the AI.

The transition model of the cars environment is known, so it can reason that "there is a very small chance this reading represents a real object and is not noise, because i did not detect anything near this position over the last 20 frames, so I'm going to assign a very low probability to it." Hence you can clean up the data really well because you're measuring an outdoor environment, not a meteor shower (or anything else where objects could appear and disappear every frame due to high velocity).

Re: How Google's Self-Driving Car Works

#54

Post by teraflop » Tue, May 08, 2012, 4:11 PM UTC

daenz wrote: post #36

Qworg wrote: post #31

Earlier quoted context omitted.

You _would_ screw it up - but only that mirror. The systems are designed for safety - the car would likely stop.

But what about reflective objects? The roadway is covered with different degrees of weirdly-reflective surfaces. Surely those beams land in places where they shouldn't (on the mirrors), and surely the car doesn't stop every time.

This isn't that much of a problem in practice. As long as the surface is partially diffuse, some of the reflected light will make it back to the sensor; light that gets scattered elsewhere is inconsequential. All you have to worry about is completely specular surfaces like mirrors, because just like a camera, the LIDAR won't be able to distinguish the reflections from real objects.

Re: How Google's Self-Driving Car Works

#55

Post by jacquesm » Tue, May 08, 2012, 4:13 PM UTC

huherto wrote: post #42

dangrossman wrote: post #32

Earlier quoted context omitted.

I don't see what Google's role is going to be, aside from pushing forward legislation for unknown reasons. The auto manufacturers don't need them for the technology and research... they've all had access to that for just as long. We'd have self-driving cars today if the public (and regulators) were ready for it. But they're not and aren't going to be overnight; what makes more sense is to gradually introduce the feat…

I don''t know. It is my impression that traditional companies are not able to produce complex software. I guess there are many paradigms that you have to break to become a software company. It seems to me that is the reason why cell phone companies ended up buying their O.S. from google.

> It is my impression that traditional companies are not able to produce complex software.

What gave you that impression?

What do you define as a non-traditional company?

Re: How Google's Self-Driving Car Works

#56

Post by div » Tue, May 08, 2012, 4:34 PM UTC

jacquesm wrote: post #55

huherto wrote: post #42

Earlier quoted context omitted.

I don''t know. It is my impression that traditional companies are not able to produce complex software. I guess there are many paradigms that you have to break to become a software company. It seems to me that is the reason why cell phone companies ended up buying their O.S. from google.

> It is my impression that traditional companies are not able to produce complex software. What gave you that impression? What do you define as a non-traditional company?

I think OP defines non-traditional in this instance as software companies.

While I believe there's room for other companies to develop self-driving navigation systems, I think the Android example is pretty apt.

It's interesting to think about when self-driving cars will actually be in stores. By then, all navigation systems will meet strict safety guidelines and some standardised tests.

If all self-drivers are equally safe, the AI's driving style will become a differentiating factor. It seems to me like Google has an advantage in this type of development, although the future can certainly prove me wrong.

Re: How Google's Self-Driving Car Works

#57

Post by bunderbunder » Tue, May 08, 2012, 4:34 PM UTC

pbw wrote: post #16

The technology is impressive, but humans drive okay without LIDAR, radar, or GPS. Maybe some day self-driving cars can drive using only two small visible-light sensors located above and behind the steering wheel. It might just be an AI challenge to operate that way, and commercial systems will always employ advanced sensors for better safety. But I don't think true parity has been reached until they can drive like we…

Two thoughts:

Cars are far-and-away the biggest killer of people in my age group. I sincerely hope that we are not going for true parity, and they will not end up driving like we do.

Using a couple stereoscopic pictures to get the lay of the land is a very, very error-prone process. Humans have to make do with it because we have very limited sensory equipment available to us. Computers can and should make use of the vastly superior technologies that they have at their disposal. One of the main points to this whole enterprise is to make better, safer cars by replacing the primary point of failure behind most collisions. Deliberately crippling the system in an effort to slavishly imitate the thing it's supposed to replace would be completely missing the point.

Re: How Google's Self-Driving Car Works

#58

Post by omegant » Tue, May 08, 2012, 4:40 PM UTC

pilgrim689 wrote: post #52

omegant wrote: post #14

It is normal for pedestrians to look for eye contact in order to know if a driver will yield the right of way or simply will accelerate and pass (in light less crosswalks). In dense pedestrian cities (I am from Spain) it is very usual to have some guessing and false start stop between the pedestrian and the driver, nobody seems to know who is going to yield finally. I wonder if this is been thought and how you'll sig…

It makes sense for the self-driving car to yield to pedestrians all the time. So if you see that there is no driver, you assume it will stop until you are out of its way. There will be no more awkward social guessing games!

There is a second part on it. How will cars behave when they are driving along a crowded street in a place where people crosses anywhere and changing directions and intentions very fast. I don't think there will be dangers to pedestrian. But it's going to be a tought problem avoiding false emergency breaking. Once more you have to rely on visual contact to know what are the real intentions of people. Crossing, waiting for the car to pass, simply unaware of the car coming, going to pick something that fell at the border of the street but no intention to cross. Not an easy task!

Also it is strange they are not working on a kind of transponder, that could be used between nearby cars to coordinate maneuvers(maybe I missed it on this article, but I think I read about somebody was developing it) . It will be usefull once robocars are more common.

Re: How Google's Self-Driving Car Works

#59

Post by zf1234 » Tue, May 08, 2012, 4:47 PM UTC

pilgrim689 wrote: post #52

omegant wrote: post #14

It is normal for pedestrians to look for eye contact in order to know if a driver will yield the right of way or simply will accelerate and pass (in light less crosswalks). In dense pedestrian cities (I am from Spain) it is very usual to have some guessing and false start stop between the pedestrian and the driver, nobody seems to know who is going to yield finally. I wonder if this is been thought and how you'll sig…

It makes sense for the self-driving car to yield to pedestrians all the time. So if you see that there is no driver, you assume it will stop until you are out of its way. There will be no more awkward social guessing games!

It will be interesting to see how people exploit the A.I.

There might be little tricks you could do to make an autonomous car yield. Or if you see one about to park, maybe you could get really close to it, and it would try to find another spot instead of fighting for the spot. Or pedestrians might carelessly walk in front of it, knowing it will stop for them.

Edit: It will also be interesting to see how the technology changes as whole fleets of them are deployed. They will constantly be sending each other data: pothole detected on highway; I'm ahead of you and have braked suddenly; this road is congested, use alternate route; is there a parking spot close to my location?; tsunami warning - all cars go to high ground.

Re: How Google's Self-Driving Car Works

#60

Post by solutionyogi » Tue, May 08, 2012, 4:52 PM UTC

omegant wrote: post #58

pilgrim689 wrote: post #52

Earlier quoted context omitted.

It makes sense for the self-driving car to yield to pedestrians all the time. So if you see that there is no driver, you assume it will stop until you are out of its way. There will be no more awkward social guessing games!

There is a second part on it. How will cars behave when they are driving along a crowded street in a place where people crosses anywhere and changing directions and intentions very fast. I don't think there will be dangers to pedestrian. But it's going to be a tought problem avoiding false emergency breaking. Once more you have to rely on visual contact to know what are the real intentions of people. Crossing, waitin…

My guess is that originally self driving cars will be mainly used on highways and take you to the metro hubs. Once you reach a very populated metro area, you will use the local public transportation.