Is this something I can use the bias for?
I don't think you'd get good results with the FFBias. that's designed for situations where you have a repeatable disturbance that you can measure in advance. what I'd recommend trying is using the SetTunings(...) function to use more conservative tunings (smaller P_Param) at higher altitudes, or when you see the controller begin to act too aggressively. that being said, I have no experience with high altitude aerodynamics, so I may not be understanding the dynamics involved
Can someone please explain what the heck the UNITS are on the PID parameters?
pfft. just keep adjusting the numbers until something works. who cares about units?! ...just kidding.
P_Param is %OutputSpan/%InputSpan (where % is calculated using the Input and Output Limits)
I_Param and D_Param are both seconds