Consider the liquid-level control system in Figure 2 below. This system has a valve, a controller, a process, and a level transmitter. The level transmitter has negligible dynamics, while the control valve has a time constant of 10 seconds. In addition, the following data is available:
A = 3 ft^2, the steady-state flow rate out, q3 = 10 gal/min, K1 = -1.3 gal/min/mA, and Km = 4 mA/ft.
Fig. 2: Liquid-level Control System + Pump in Exit Line
a) Develop the block diagram (35 points)
b) Derive the set-point transfer function (10 points)
c) Determine the numerical values of Kc and Ï„ for a Proportional Integral controller that will result in a stable closed-loop system. (20 points)