10 ms·

it snowed a few weekends ago in Chicago, my autopilot turned off because snow covered up the cameras. So I am not buying all this "self driving with no lidar" b

it snowed a few weekends ago in Chicago, my autopilot turned off because snow covered up the cameras. So I am not buying all this "self driving with no lidar" brouhaha

ubercow13 8y ago
Can snow cover lidars?
- asteli 8y ago
  Depends on the unit. On some designs (e.g. Velodyne HDL-64) the unit is split into two sections. The whole upper section, along with all the optics and some of the electronics, spins at 10-15 Hz, which naturally tends to shed precipitation and other crud. Sensors with non-moving optical windows can use other strategies, such as air knives or wipers.
slg 8y ago
Doesn't LIDAR has similar problems with precipitation? Regardless of what solution proves to be the best, there is going to be a decent amount of time between when a self driving car can handle most scenarios and when it can handle all possible scenarios.
- semi-extrinsic 8y ago
  Here's a snow cover map of North America on a random day in January: https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/USA/2019/ims2019025_usa.gif https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/U... Here is Europe and Asia on the same day: https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/EuAsia/2019/ims2019025_asiaeurope.gif https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/E... For someone who lives in or close to that white part, "most scenarios" includes snow. Arguably for Level 4 autonomous cars in those areas, you either need to fully disable autonomy in September and enable it again in late April, or you'll need to handle snow.
  - slg 8y ago
    You are comparing two different things. Old snow on the ground (your images) is not the same thing as active or recent snow accumulation on the vehicle (the original comment). It is completely reasonable for the car to disable autonomy due to snow accumulation until someone clears it off the vehicle. That says nothing about the autonomy of the vehicle with snow cover on the ground.
    - semi-extrinsic 8y ago
      I'm assuming Level 4 is what Musk means by Full Self Driving. The bar to be passed is then "No driver attention is ever required for safety (...) self-driving is only supported in limited circumstances (e.g. geofencing), and when these circumstances are no longer met the vehicle must be able to safely abort the trip, e.g. park the car, if the driver does not retake control." How would that work if you're out driving on the highway, and it starts snowing hard so the car can't see anything? Just park on the highway? If your car can't safely handle such a scenario, the automous feature would have to be "season-fenced" in addition to geofenced.
      - slg 8y ago
        It isn’t like it all cameras simultaneously go from 0% obstruction to 100% obstruction instantaneously. The car should pull off the highway and park or at least pull to the shoulder and park once it has identified decreased visibility to an extent that might impact safety.
        semi-extrinsic 8y ago
        It kinda is though. Snow deposition is a function of surface temperature, which is uniform across the sensor. Hit the wrong initial temp when you enter a blizzard, and deposition takes your vision in seconds. It can be hard enough to see out the windshield which has heating, wipers and anti-freeze wiper fluid fighting for it.
        8y ago
- Obi_Juan_Kenobi 8y ago
  Water affects certain wavelengths, and there's been good progress on LIDAR that uses wavelengths that aren't effected. Most approaches want to use a wavelength that has as little ambient light as possible. That light is absent precisely because it is absorbed by water vapor in the atmosphere. The alternative approach must deal with lower signal:noise, but is not substantially affected by weather.
mhb 8y ago
OK but snow blocks lidar too.
- penny45 8y ago
  snow might ruin it for everyone. Winter is coming, and we're all screwed...
mrtron 8y ago
Not cleaning snow off of your vehicle before driving is crazy.
oska 8y ago
And would you drive if snow covered your windscreen? Or would you clean it? Which is obviously possible for cameras too.
- jsharf 8y ago
  The windscreen has wipers, on the Tesla model 3, I don't think all the sensors have wipers... so that's an issue.
  - oska 8y ago
    Yes, we implemented simple physical solutions such as wipers and window heaters in cars to maintain vision for drivers. What we didn't do was implement lidar to aid human drivers. Simple physical solutions are available if necessary for the cameras too. I don't have a tesla so I don't know what measures they use to keep the cameras clean but I'm sure they've thought about it and designed for it.
    - pwinnski 8y ago
      Great-grandparent comment suggests that they did not, in fact, design for it. Assuming the best is nice when you have no information, but we have information.
      - oska 8y ago
        I'm not assuming the best, I'm assuming basics. We've just watched a presentation where Tesla put immense resources and talent into designing a state of the art vision processing chip. Do you think they're going to let it be rendered useless by not implementing simple physical measures to keep vision coming in from the cameras? (What measures are already there plus easy opportunity for improvement). Of course not. Such a line of argumentation is transparently bogus. I don't know why the top level commenter's autopilot turned off in the snow but trying to argue that that shows that snow renders cameras useless and makes lidar necessary is stupid. Sorry for the strong language but really, I don't know how else to put it.
buildbot 8y ago
Snow completely disables lidar as well if I recall correctly. Only radar will work in a snowstorm.
tigershark 8y ago
Lidar is useless when snowing

it snowed a few weekends ago in Chicago, my autopilot turned off because snow covered up the cameras. So I am not buying all this "self driving with no lidar" brouhaha

ubercow13 8y ago

Can snow cover lidars?

asteli 8y ago
Depends on the unit. On some designs (e.g. Velodyne HDL-64) the unit is split into two sections. The whole upper section, along with all the optics and some of the electronics, spins at 10-15 Hz, which naturally tends to shed precipitation and other crud. Sensors with non-moving optical windows can use other strategies, such as air knives or wipers.

slg 8y ago

Doesn't LIDAR has similar problems with precipitation? Regardless of what solution proves to be the best, there is going to be a decent amount of time between when a self driving car can handle most scenarios and when it can handle all possible scenarios.

semi-extrinsic 8y ago
Here's a snow cover map of North America on a random day in January: https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/USA/2019/ims2019025_usa.gif https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/U... Here is Europe and Asia on the same day: https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/EuAsia/2019/ims2019025_asiaeurope.gif https://www.natice.noaa.gov/pub/ims/ims_v3/ims_gif/ARCHIVE/E... For someone who lives in or close to that white part, "most scenarios" includes snow. Arguably for Level 4 autonomous cars in those areas, you either need to fully disable autonomy in September and enable it again in late April, or you'll need to handle snow.
- slg 8y ago
  You are comparing two different things. Old snow on the ground (your images) is not the same thing as active or recent snow accumulation on the vehicle (the original comment). It is completely reasonable for the car to disable autonomy due to snow accumulation until someone clears it off the vehicle. That says nothing about the autonomy of the vehicle with snow cover on the ground.
  - semi-extrinsic 8y ago
    I'm assuming Level 4 is what Musk means by Full Self Driving. The bar to be passed is then "No driver attention is ever required for safety (...) self-driving is only supported in limited circumstances (e.g. geofencing), and when these circumstances are no longer met the vehicle must be able to safely abort the trip, e.g. park the car, if the driver does not retake control." How would that work if you're out driving on the highway, and it starts snowing hard so the car can't see anything? Just park on the highway? If your car can't safely handle such a scenario, the automous feature would have to be "season-fenced" in addition to geofenced.
    - slg 8y ago
      It isn’t like it all cameras simultaneously go from 0% obstruction to 100% obstruction instantaneously. The car should pull off the highway and park or at least pull to the shoulder and park once it has identified decreased visibility to an extent that might impact safety.
      - semi-extrinsic 8y ago
        It kinda is though. Snow deposition is a function of surface temperature, which is uniform across the sensor. Hit the wrong initial temp when you enter a blizzard, and deposition takes your vision in seconds. It can be hard enough to see out the windshield which has heating, wipers and anti-freeze wiper fluid fighting for it.
        8y ago
Obi_Juan_Kenobi 8y ago
Water affects certain wavelengths, and there's been good progress on LIDAR that uses wavelengths that aren't effected. Most approaches want to use a wavelength that has as little ambient light as possible. That light is absent precisely because it is absorbed by water vapor in the atmosphere. The alternative approach must deal with lower signal:noise, but is not substantially affected by weather.

mhb 8y ago

OK but snow blocks lidar too.

penny45 8y ago
snow might ruin it for everyone. Winter is coming, and we're all screwed...

mrtron 8y ago

Not cleaning snow off of your vehicle before driving is crazy.

oska 8y ago

And would you drive if snow covered your windscreen? Or would you clean it? Which is obviously possible for cameras too.

jsharf 8y ago
The windscreen has wipers, on the Tesla model 3, I don't think all the sensors have wipers... so that's an issue.
- oska 8y ago
  Yes, we implemented simple physical solutions such as wipers and window heaters in cars to maintain vision for drivers. What we didn't do was implement lidar to aid human drivers. Simple physical solutions are available if necessary for the cameras too. I don't have a tesla so I don't know what measures they use to keep the cameras clean but I'm sure they've thought about it and designed for it.
  - pwinnski 8y ago
    Great-grandparent comment suggests that they did not, in fact, design for it. Assuming the best is nice when you have no information, but we have information.
    - oska 8y ago
      I'm not assuming the best, I'm assuming basics. We've just watched a presentation where Tesla put immense resources and talent into designing a state of the art vision processing chip. Do you think they're going to let it be rendered useless by not implementing simple physical measures to keep vision coming in from the cameras? (What measures are already there plus easy opportunity for improvement). Of course not. Such a line of argumentation is transparently bogus. I don't know why the top level commenter's autopilot turned off in the snow but trying to argue that that shows that snow renders cameras useless and makes lidar necessary is stupid. Sorry for the strong language but really, I don't know how else to put it.

buildbot 8y ago

Snow completely disables lidar as well if I recall correctly. Only radar will work in a snowstorm.

tigershark 8y ago

Lidar is useless when snowing