A control system for controlling the pressv.re m a closed chamber is shown below, together with its flow graph model.

Desire~ Controller pressure Irrfmite pressure r---Y'

source 1

Pressure Controller Controller De (s)

Valve

-H(s)

Measurement Flow Graph Model The transfer function for the measuring element is G(s) _ 100 - s2 + I5s + 100'

and the transfeT function for the valve is 1

Dl(s) = (0.1s + 1)(s/15 + 1) ·

The contmLler function is given by Obtain the frequency response characteristics for the loop transfer function Dc(s)DI(s)G(s) [~].
Problem