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I'm sure someone more qualified to than me is floating around here. From what I heard at CMU then, the GPS data in '04 was a couple feet off, and everyone was d

by jowiar 10y ago

I'm sure someone more qualified to than me is floating around here. From what I heard at CMU then, the GPS data in '04 was a couple feet off, and everyone was driving a few feet off the road as a result. I imagine the key takeaway then was that one couldn't depend on GPS.

olivercameron 10y ago
Localization is a really hard problem!
Animats 10y ago
That caused us trouble in the 2005 Grand Challenge. It turns out that Novatel and Garmin GPSs were about a meter apart. They're both applying corrections for atmospheric distortion obtained from ground stations and distributed through a geostationary satellite, which can give 15cm precision. We had Novatel, and DARPA had measured the course with Garmin. I talked to the JPL team, which also had Novatel, and they had a similar error. We were strictly obeying the course boundaries, and had a terrible time getting through narrow gates where DARPA's waypoint file had a narrow width designed to guide us through the gates. If you look at videos of our runs, you can see the vehicle backing up and trying to get through a narrow obstacle. It's trying to get past a real-world obstacle on one side and a GPS limit on the other, which has narrowed the allowed path to where it can't quite fit. So for the second run, I put in a patch to add 1 meter to DARPA's lane width. But I forgot to push it out to the vehicle, and we botched the second test run. It was in place for the third test run, though.
- tamana 10y ago
  DARPA gave you bad data and told you you had to use it? Why would your system insist on staying within DARPA's boundaries in the first place -- did they make "out of bounds" too narrow in a misguided attempt to be helpful?
  - IncRnd 10y ago
    Do you think that self-driving cars get clean correct data as input?
    - rs999gti 10y ago
      Don't Tesla's? They require a well defined road line otherwise they get confused. My friend owns a Model S and on the way to lunch it got confused on off ramps and parts of the road that were not well defined by lines. It basically shut off autopilot and required my friend to take the wheel.
      - toomuchtodo 10y ago
        This should be much improved in version 8 of the Tesla OS going out Wednesday.
      - IncRnd 10y ago
        That they get confused and shut off autopilot shows they do not get clean correct data.
      - jacquesm 10y ago
        It should take a lot more than a bit of paint on the road to upset a self driving car.
  - Animats 10y ago
    Yes, they made "out of bounds" too narrow in an attempt to be helpful. The data file provided to each team just before each event was a set of GPS waypoints, each with a width. The width of each segment was the minimum of the width at the endpoints. In the 2004 Grand Challenge, the bounds were much wider and most vehicles screwed up. As it turned out, you could almost drive the 2005 Grand Challenge by staying centered in the DARPA-defined path. But we didn't know that in advance.
dschiptsov 10y ago
Driving based on GPS instead of actual road perceived through cameras would be a disaster.

by jowiar 10y ago

olivercameron 10y ago

Localization is a really hard problem!

Animats 10y ago

That caused us trouble in the 2005 Grand Challenge. It turns out that Novatel and Garmin GPSs were about a meter apart. They're both applying corrections for atmospheric distortion obtained from ground stations and distributed through a geostationary satellite, which can give 15cm precision. We had Novatel, and DARPA had measured the course with Garmin. I talked to the JPL team, which also had Novatel, and they had a similar error. We were strictly obeying the course boundaries, and had a terrible time getting through narrow gates where DARPA's waypoint file had a narrow width designed to guide us through the gates. If you look at videos of our runs, you can see the vehicle backing up and trying to get through a narrow obstacle. It's trying to get past a real-world obstacle on one side and a GPS limit on the other, which has narrowed the allowed path to where it can't quite fit. So for the second run, I put in a patch to add 1 meter to DARPA's lane width. But I forgot to push it out to the vehicle, and we botched the second test run. It was in place for the third test run, though.

tamana 10y ago
DARPA gave you bad data and told you you had to use it? Why would your system insist on staying within DARPA's boundaries in the first place -- did they make "out of bounds" too narrow in a misguided attempt to be helpful?
- IncRnd 10y ago
  Do you think that self-driving cars get clean correct data as input?
  - rs999gti 10y ago
    Don't Tesla's? They require a well defined road line otherwise they get confused. My friend owns a Model S and on the way to lunch it got confused on off ramps and parts of the road that were not well defined by lines. It basically shut off autopilot and required my friend to take the wheel.
    - toomuchtodo 10y ago
      This should be much improved in version 8 of the Tesla OS going out Wednesday.
    - IncRnd 10y ago
      That they get confused and shut off autopilot shows they do not get clean correct data.
    - jacquesm 10y ago
      It should take a lot more than a bit of paint on the road to upset a self driving car.
- Animats 10y ago
  Yes, they made "out of bounds" too narrow in an attempt to be helpful. The data file provided to each team just before each event was a set of GPS waypoints, each with a width. The width of each segment was the minimum of the width at the endpoints. In the 2004 Grand Challenge, the bounds were much wider and most vehicles screwed up. As it turned out, you could almost drive the 2005 Grand Challenge by staying centered in the DARPA-defined path. But we didn't know that in advance.

dschiptsov 10y ago

Driving based on GPS instead of actual road perceived through cameras would be a disaster.