4 ms·

You made a servo.

• seiferteric 10y ago
  Yes that's true, just wanted to explain the mechanism behind it. Just a note, I don't think most hobby type servos implement full PID control, though many industrial ones do I am sure.
  • snovv_crash 10y ago
    Hobby servos often have controllers far more complex and accurate than PID. Something taking into account the gearbox and motor inertia, input voltage, etc. And not just tuned with high pass, low pass and gain filters.
    • seiferteric 10y ago
      Is that true? I know there are more optimal control schemes than PID IF you know the parameters of the load, but with a servo you could connect anything to it, so its not just the gearbox and motor, so how would it handle it? I would love to see some implementation code or diagram of a hobby servo control. Also my understanding is that PID is optimal IF you don't know about the load, but maybe that is wrong, its been a while. My impression was that hobby servos used basically just PI control and were heavily damped so you don't really get overshoot, but again I don't really know.
      • snovv_crash 10y ago
        The cheap, older 'analogue' servos were just PI, but the new 'digital' servos have much more advanced control. They actively reverse power to the motor when getting close to the target to extract regen power from the motor inertia while still getting a faster response. Yes, you can get this from PID, but you can't keep it at full reverse right up to the moment it hits the target without getting nasty oscillations as the voltage changes.