We tuned the HEPI pump controller that will regulate the pump speed such that the pressure drop between the chamber inlet manifold and the chamber outlet manifold stays constant. Since there is no chamber hooked up, we controlled the pressure at sensor 4 (after 3 accumulators) on the manifold.
We identified the pump dynamic using a step response. Next, we approximated the pump with a simple model. Then, we tweaked the parameters of the controller using the model. Finally, we measured the closed loop response.
In attachment, you will find:
-	Amplitude spectral density of pressure at sensor 1 (after 1 accumulator) and sensor 4 (after 3 accumulators) for different revolution speeds of the pump.
-	Times series (Step response: Simulations vs measurements)
-	Bode plot (Pump, Open Loop, Closed Loop …). UUG=4.5mHz – Phase margin 60 deg.