Velocity PID(F) Best Practices - To Integrate, or Not To Integrate?

[AdamHeard]

Originally Posted by calcmogul

So mathematically speaking, an integrator is required to eliminate steady-state error in all cases for this model. If you don't want to use one, a feedforward can eliminate most if not all of the error if chosen carefully. Given that, there is always uncertainty, hence why feedback control exists.

In the practical sense most teams are just looking for consistent RPM within a tight band near the setpoint.

If the system inertia is large enough compared to the motor power and the control frequency high enough you'll get high frequency oscillations of low magnitude around the setpoint (as Jared and Oblarg detailed above).

So, you need an integrator to eliminate steady state error in a theoretical sense, but not necessarily in a practical sense depending on the system.