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dead reckoning has to account for currents etc, which is something you could use AI to improve as per the paper. It's actually a _good_ application of AI? Sub

dead reckoning has to account for currents etc, which is something you could use AI to improve as per the paper. It's actually a _good_ application of AI? Subs use very expensive and very impressive inertial guidance systems, which can go up-to a week without correction. But that doesn't scale down to the modern world of small autonomous systems.

actionfromafar 3y ago
The currents would accelerate the dead reckoning unit just like any other force, including from the impellers. Not arguing that small autonomous systems could use something smaller and cheaper.
- chrisdalke 3y ago
  many INS packages also include a DVL (Doppler velocity log) which measures speed over ground if you’re in range of the bottom.
- willvarfar 3y ago
  The dead reckoning itself doesn't detect the ocean currents; these are separate estimates that need to be integrated to determine actual position https://en.wikipedia.org/wiki/Submarine_navigation#Deep_water_navigation https://en.wikipedia.org/wiki/Submarine_navigation#Deep_wate...
  - actionfromafar 3y ago
    Huh, I don't understand why. :-D Someone please explain. If I tugged the sub, wouldn't the IMU detect that? Why is a current doing the tugging any different.
    - willvarfar 3y ago
      now I'm guessing, but perhaps it's like if you walk up the aisle of a moving train, how fast are you travelling? And how fast does it feel like you're travelling?
      - actionfromafar 3y ago
        Sure, I would get confused by that too, but I thought the point of the IMU is that it has its own frame of reference. Elsewhere in these comments was someone mentioning an IMU which could detect a building growing in size when warmer. The IMU doesn't "know" there's water outside or how the water is moving. It knows how much force it's been pushed around by.
        willvarfar 3y ago
        Aha! IMU <> "dead reckoning"? In the wikipedia article they are listed separately. Dead reckoning is meaning tracking things like the revolutions of a propeller and a compass to compute position, whereas an IMU is three accelerometers, three gyros and three magnetometers? https://en.wikipedia.org/wiki/Inertial_measurement_unit https://en.wikipedia.org/wiki/Inertial_measurement_unit
        actionfromafar 3y ago
        Haha oops. :-)

actionfromafar 3y ago

The currents would accelerate the dead reckoning unit just like any other force, including from the impellers. Not arguing that small autonomous systems could use something smaller and cheaper.

chrisdalke 3y ago
many INS packages also include a DVL (Doppler velocity log) which measures speed over ground if you’re in range of the bottom.
willvarfar 3y ago
The dead reckoning itself doesn't detect the ocean currents; these are separate estimates that need to be integrated to determine actual position https://en.wikipedia.org/wiki/Submarine_navigation#Deep_water_navigation https://en.wikipedia.org/wiki/Submarine_navigation#Deep_wate...
- actionfromafar 3y ago
  Huh, I don't understand why. :-D Someone please explain. If I tugged the sub, wouldn't the IMU detect that? Why is a current doing the tugging any different.
  - willvarfar 3y ago
    now I'm guessing, but perhaps it's like if you walk up the aisle of a moving train, how fast are you travelling? And how fast does it feel like you're travelling?
    - actionfromafar 3y ago
      Sure, I would get confused by that too, but I thought the point of the IMU is that it has its own frame of reference. Elsewhere in these comments was someone mentioning an IMU which could detect a building growing in size when warmer. The IMU doesn't "know" there's water outside or how the water is moving. It knows how much force it's been pushed around by.
      - willvarfar 3y ago
        Aha! IMU <> "dead reckoning"? In the wikipedia article they are listed separately. Dead reckoning is meaning tracking things like the revolutions of a propeller and a compass to compute position, whereas an IMU is three accelerometers, three gyros and three magnetometers? https://en.wikipedia.org/wiki/Inertial_measurement_unit https://en.wikipedia.org/wiki/Inertial_measurement_unit
        actionfromafar 3y ago
        Haha oops. :-)