5 ms·

I think the LIDAR approach will have to go. Laser systems are inherently susceptible to jamming with a cheap laser diode. We cannot afford to have mass adoption

I think the LIDAR approach will have to go. Laser systems are inherently susceptible to jamming with a cheap laser diode. We cannot afford to have mass adoption of cars where somebody can create weeks of citywide gridlock with a few thousand dollars of lasers.

zitterbewegung 14y ago
The degradation mode is that you have to drive your car. Not, everyone not being able to drive.
- JulianMorrison 14y ago
  You assume that the car is occupied by a sober adult who can drive. Not something you'll be able to assume any more when mom can send the car to do the school run.
- Daniel_Newby 14y ago
  You cannot drive your car in 1 meter spaced convoys. In many cities jamming the navigators would cause the cars to not fit on the roads, resulting in gridlock for however long the jammers could be kept going.
  - Aloisius 14y ago
    And dumping 500 caltrops off an overpass would likely have the exact same effect. Worrying about someone actively attacking this kind of system using theoretical jammers that could seize up multiple lanes of traffic (without easy line of sight!) and operate for hundreds of feet at this point seems premature.
    - Daniel_Newby 14y ago
      You can't do the caltrop trick at 50 locations for weeks on end. The thing about lasers is they use a very narrow slice of wavelengths. Environmental light like sunlight has very little power within that slice, so its easy for the LIDAR to see its own laser. But that makes it really easy to jam. You could probably build a jammer today for a few hundred dollars, which means that in the future every disaffected monkeywrencher will do it. Ergo the approach is not suitable for the mass market.
    - flyinRyan 14y ago
      I hate what 911 has done to people's thinking. We're talking about the future here but people can't stop with their fantasy bond villain nonsense.
agildehaus 14y ago
Thrun said in a talk I saw posted on HN earlier today that this wasn't being considered a problem. I'm not certain if targeted LIDAR jamming was on his mind, his comment was specifically in reference to operating with many other autonomous cars on the road. He was concerned about GPS jamming though, but thankfully these cars have been designed from the ground up to not rely on GPS (as a signal from a satellite is not reliable). I believe as long as the area has been 3D mapped by Google, the car is capable of driving and navigating without GPS assistance.
paulsutter 14y ago
You can jam the human eye with a cheap laser diode. Does that stop you from driving? Besides, using the right modulation would make LIDAR as hard to jam as would be needed.
- Daniel_Newby 14y ago
  The eye is broadband and the desired light is bright, so it takes a very high power density to jam it. LIDAR receivers are very narrowband and the desired light is fairly dim, so jamming it will be quite easy. Modulation does not help when the light detector is saturated.
  - paulsutter 14y ago
    To keep the detector saturated for any period of time you would need to have aim that's a little too perfect. Besides, my central point was that there are lots of vulnerabilities in existing cars and they're still driven. In case you decide to test your theory about lasers and human eyes, please don't use someone else as a test subject.
    - Daniel_Newby 14y ago
      I think it can be done without aiming, assuming the light detector uses a wide angle lens. You just have to illuminate the scene observed by the LIDAR with a few watts per square meter of laser light. That's doable today, and easy in the future.

zitterbewegung 14y ago

The degradation mode is that you have to drive your car. Not, everyone not being able to drive.

JulianMorrison 14y ago
You assume that the car is occupied by a sober adult who can drive. Not something you'll be able to assume any more when mom can send the car to do the school run.
Daniel_Newby 14y ago
You cannot drive your car in 1 meter spaced convoys. In many cities jamming the navigators would cause the cars to not fit on the roads, resulting in gridlock for however long the jammers could be kept going.
- Aloisius 14y ago
  And dumping 500 caltrops off an overpass would likely have the exact same effect. Worrying about someone actively attacking this kind of system using theoretical jammers that could seize up multiple lanes of traffic (without easy line of sight!) and operate for hundreds of feet at this point seems premature.
  - Daniel_Newby 14y ago
    You can't do the caltrop trick at 50 locations for weeks on end. The thing about lasers is they use a very narrow slice of wavelengths. Environmental light like sunlight has very little power within that slice, so its easy for the LIDAR to see its own laser. But that makes it really easy to jam. You could probably build a jammer today for a few hundred dollars, which means that in the future every disaffected monkeywrencher will do it. Ergo the approach is not suitable for the mass market.
  - flyinRyan 14y ago
    I hate what 911 has done to people's thinking. We're talking about the future here but people can't stop with their fantasy bond villain nonsense.

agildehaus 14y ago

Thrun said in a talk I saw posted on HN earlier today that this wasn't being considered a problem. I'm not certain if targeted LIDAR jamming was on his mind, his comment was specifically in reference to operating with many other autonomous cars on the road. He was concerned about GPS jamming though, but thankfully these cars have been designed from the ground up to not rely on GPS (as a signal from a satellite is not reliable). I believe as long as the area has been 3D mapped by Google, the car is capable of driving and navigating without GPS assistance.

paulsutter 14y ago

You can jam the human eye with a cheap laser diode. Does that stop you from driving? Besides, using the right modulation would make LIDAR as hard to jam as would be needed.

Daniel_Newby 14y ago
The eye is broadband and the desired light is bright, so it takes a very high power density to jam it. LIDAR receivers are very narrowband and the desired light is fairly dim, so jamming it will be quite easy. Modulation does not help when the light detector is saturated.
- paulsutter 14y ago
  To keep the detector saturated for any period of time you would need to have aim that's a little too perfect. Besides, my central point was that there are lots of vulnerabilities in existing cars and they're still driven. In case you decide to test your theory about lasers and human eyes, please don't use someone else as a test subject.
  - Daniel_Newby 14y ago
    I think it can be done without aiming, assuming the light detector uses a wide angle lens. You just have to illuminate the scene observed by the LIDAR with a few watts per square meter of laser light. That's doable today, and easy in the future.