Hello! I've been trying to study PID and especially the coding implementations of the PID controller onto the ArduCopter code (which I would use for a quadrotor)... So when I was researching, I found several formulas on the altitude control of the PID which they normally call U1 in online journals (as for the motor inputs)... I've noticed that the altitude control using PID made use of the following formula:
U1 = [m/(cos theta * cos phi]*( PID )
so I've seen the PID controllers on the code in the AC_PosControl.cpp accel_to_throttle function... however I could not see the m/(cos theta * cos phi) anywhere... well I've seen something like it in get_throttle_boosted function in AC_AttitudeControl_Multi.cpp... and they pretty much multiplied the PID term with 1/(cos theta * cos phi) which resembles the formula presented above... however I could not detect the m term...
So I'm asking if there's really an m term involved... or did they use a different formula... but if there is an m term in their formula, I would really appreciate if you guys can point it to me.
Thanks!
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