A liquid vessel has an inlet and an outlet streams. The outlet stream flows through a valve having a resistance R. To control the level at a specified value a PI (Proportional-Integral) controller placed on the inlet stream is used. You have been tasked with the design of the control system.

Assume that the outflow can be expressed as (/) where is the level in the surge vessel and is the valve resistance to flow.

Control valve transfer function = 1

Transmitter transfer function = 1

Surge vessel area 5 m2

Liquid level 2 m

Liquid flowrate 5 m3 /min.

10. If instead of feedback control feedforward control is desired how would implement such feedforward control in this process? Draw a diagram to illustrate your solution.