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Quick, what's the reaction time for Waymo's driverless cars? Support your answer with evidence. For extra credit: describe what the reaction time is for Waymo

Quick, what's the reaction time for Waymo's driverless cars? Support your answer with evidence. For extra credit: describe what the reaction time is for Waymo's driverless cars are during various points of the garbage collection cycle. People here have a tendency to imagine an idealized version of driverless cars and assume that actual driverless cars are the idealized versions of those cars, and then compare the idealized cars to very non-idealized humans. I think that the real world is going to be more complicated than that. It is easy to write code that takes a non-trivial amount of time to process to the point of output on any given hardware. I imagine that all of us have done that at various times. We can certainly imagine that reaction time could be a virtue of driverless cars -- even 99th percentile reaction time. Given sufficient hardware (and not just hardware on the core CPU/ram chips -- this is hardware out to the sensors and the subprocessors associated with each of them). Similarly, we could imagine putting enough sensors on the vehicle that it truly has 360 degree awareness and visibility. But we do see real cars in the real world that have surprising blindspots. There are cost tradeoffs to all of these things, and complexity tradeoffs. Is there a happy medium? I think that there very likely is, even without any fundamental advances in the state of the art. Are we within a year or two of that happy medium? Maybe.

weaksauce 10y ago
> we could imagine putting enough sensors on the vehicle that it truly has 360 degree awareness and visibility. But we do see real cars in the real world that have surprising blindspots. Not sure I see the point you are making... all cars have blind spots with drivers now. Human drivers are always blind to the spots they are not looking at the moment anyway. I can imagine cars being much safer than they are now.
- aetherson 10y ago
  I can imagine this too! But when you look at how you imagine driverless cars to be, you might want to temper your imagination with how driverless cars actually behave, such as the Tesla running into a trailer because it was too high off the ground for its ultrasound sensors to detect. http://www.theverge.com/2016/5/11/11656496/tesla-model-s-autonomous-summon-mode-crash http://www.theverge.com/2016/5/11/11656496/tesla-model-s-aut... (Note that this is not the famous case of the Tesla being unable to detect a white semi against a bright sky, it's a low speed no-injuries collision). Obviously, Tesla is not the be-all and end-all of driverless cars. But when you're dealing with sensors combined with AI where each is in many ways less capable than the human eye, with different failure modes, it gets expensive and difficult to design really good fields of vision.
31reasons 10y ago
>>Waymo's driverless cars are during various points of the garbage collection cycle. you can say the same thing for rockets. There is entire field dedicated to this, its called Realtime Systems.
1123581321 10y ago
You've asked an interesting question. I can't find a good source on what is the range of reaction times for autonomous vehicles. However, in the test videos I've seen, they appear to be human-level or better. For reference, human reaction times (to start braking) are typically between .5-2 seconds. It's difficult for humans to react to anything in under .25 seconds. I don't think it's controversial to say that machines can easily beat those human reaction times. Most or all autonomous vehicle software is written in C++, so garbage collection shouldn't be an issue. Of course, these programs need to be tested carefully and extremely before we trust them.
joshuamorton 10y ago
>Quick, what's the reaction time for Waymo's driverless cars? Support your answer with evidence. >For extra credit: describe what the reaction time is for Waymo's driverless cars are during various points of the garbage collection cycle. Aight, I'm not familiar with Waymo's cars specifically, but with <10K in hardware (maybe <5K now) you can design and build an autonomous vehicle kit that has a reaction loop that runs at a soft floor of 15 adjustments per second. I'm sure that with better hardware you can increase that to 60+, and 15 per second is already about 5x better than human reaction time, and fast enough that it can react to changes every 6 feet at highway speeds, and every foot at neighborhood speeds. A 60 aps loop means that its recalculating everything every 2 feet your car travels on the highway. And yes, this isn't incredibly difficult. For reference, in my experience, running 2 cameras and a low power lidar (along with associated outputs to hardware actuators and such) off of a 2013 (or maybe a 2011) macbook pro, the limiting factor was always the lidar's 15fps framerate.
maverick_iceman 10y ago
Don't you think the engineers building self-driving cars would consider reaction times and make adequate safeguards? If your thesis requires a group of very smart people to be completely oblivious to a very basic issue for multiple years, then you should reconsider your thesis.

weaksauce 10y ago

> we could imagine putting enough sensors on the vehicle that it truly has 360 degree awareness and visibility. But we do see real cars in the real world that have surprising blindspots. Not sure I see the point you are making... all cars have blind spots with drivers now. Human drivers are always blind to the spots they are not looking at the moment anyway. I can imagine cars being much safer than they are now.

aetherson 10y ago
I can imagine this too! But when you look at how you imagine driverless cars to be, you might want to temper your imagination with how driverless cars actually behave, such as the Tesla running into a trailer because it was too high off the ground for its ultrasound sensors to detect. http://www.theverge.com/2016/5/11/11656496/tesla-model-s-autonomous-summon-mode-crash http://www.theverge.com/2016/5/11/11656496/tesla-model-s-aut... (Note that this is not the famous case of the Tesla being unable to detect a white semi against a bright sky, it's a low speed no-injuries collision). Obviously, Tesla is not the be-all and end-all of driverless cars. But when you're dealing with sensors combined with AI where each is in many ways less capable than the human eye, with different failure modes, it gets expensive and difficult to design really good fields of vision.

31reasons 10y ago

>>Waymo's driverless cars are during various points of the garbage collection cycle. you can say the same thing for rockets. There is entire field dedicated to this, its called Realtime Systems.

1123581321 10y ago

You've asked an interesting question. I can't find a good source on what is the range of reaction times for autonomous vehicles. However, in the test videos I've seen, they appear to be human-level or better. For reference, human reaction times (to start braking) are typically between .5-2 seconds. It's difficult for humans to react to anything in under .25 seconds. I don't think it's controversial to say that machines can easily beat those human reaction times. Most or all autonomous vehicle software is written in C++, so garbage collection shouldn't be an issue. Of course, these programs need to be tested carefully and extremely before we trust them.

joshuamorton 10y ago

>Quick, what's the reaction time for Waymo's driverless cars? Support your answer with evidence. >For extra credit: describe what the reaction time is for Waymo's driverless cars are during various points of the garbage collection cycle. Aight, I'm not familiar with Waymo's cars specifically, but with <10K in hardware (maybe <5K now) you can design and build an autonomous vehicle kit that has a reaction loop that runs at a soft floor of 15 adjustments per second. I'm sure that with better hardware you can increase that to 60+, and 15 per second is already about 5x better than human reaction time, and fast enough that it can react to changes every 6 feet at highway speeds, and every foot at neighborhood speeds. A 60 aps loop means that its recalculating everything every 2 feet your car travels on the highway. And yes, this isn't incredibly difficult. For reference, in my experience, running 2 cameras and a low power lidar (along with associated outputs to hardware actuators and such) off of a 2013 (or maybe a 2011) macbook pro, the limiting factor was always the lidar's 15fps framerate.

maverick_iceman 10y ago

Don't you think the engineers building self-driving cars would consider reaction times and make adequate safeguards? If your thesis requires a group of very smart people to be completely oblivious to a very basic issue for multiple years, then you should reconsider your thesis.