5 ms·

Yes, Hesai LiDAR [1] bug is grounding cars. [1] https://pandaily.com/hesai-technology-addresses-lidar-products-bug/ https://pandaily.com/hesai-technology-addre

• trebligdivad 3y ago
  Fascinating - why does a LiDAR involve the date?
  • worik 3y ago
    For the survalence records Telling base where, and when, you were
    • nemomarx 3y ago
      Shouldn't that just be a unix timestamp or something? You'd think resolving that to a date time could be done in the UI instead of in the business logic
      • topaz0 3y ago
        "should"
      • defrost 3y ago
        Unix time has discrepancies whenever leap seconds occur (several times in my career aquiring geophysical data). If you're measuring | controlling objects in the physical world (cars, rockets, etc) then you should not use unix time - those glitches will happen and instantaneous computations will go kooky. https://en.wikipedia.org/wiki/Unix_time#Leap_seconds https://en.wikipedia.org/wiki/Unix_time#Leap_seconds
        • redox99 3y ago
          But so does resolving to a date. I don't see how resolving to a date which cares about leap days fixes any of that. You should use a monotonic clock with an arbitrary starting point anyway, unless you need some kind of synchronization between devices, but you probably wouldn't use unixtime there anyway.
          • defrost 3y ago
            > But so does resolving to a date. I don't see how resolving to a date which cares about leap days fixes any of that. So why bring it up then? > You should use a monotonic clock with an arbitrary starting point anyway Sure. We started doing that more than 50 years ago now when broad area geophysical surveying started off. > unless you need some kind of synchronization between devices, Can't see the problem - there are ways of syncing base station records against aircraft | boat | vehicle records in post processing .. all the stations, fixed or mobile, use a monotonic epoch based record structure that hold channel data and any sync marks that are broadcast by whatever means - raw GPS time serves well enough for a grain of 1.5 seconds, other marks can be used as required.
      • trebligdivad 3y ago
        I think I'd have used time-since-power-on; your infotainment system could take an RTC offset to get that to human dates.
  • bnqscrtm 3y ago
    LiDARs and other sensors typically need to be time-synchronized with the rest of the robotic system. I wouldn't be surprised if the bug is related to that.
    • deleted 3y ago
      [deleted]