The distillation column in Fig. 15.8 has the following transfer function model:

with G_v = G_m = G_t = 1.
(a) Design a feedforward controller based on a steady-state analysis.
(b) Design a feedforward controller based on a dynamic analysis.
(c) Design a PI feedback controller based on the Direct Synthesis approach of Chapter 12 with Ï„_c = 30.
(d) Simulate the closed-loop response to a unit step change in
the disturbance variable using feedforward control only and the controllers of parts (a) and (b). Does the dynamic controller of part (b) provide a signifcant improvement?
(e) Repeat part (d) for the feedforward€“feedback control scheme of Fig. 15.11 and the controllers of parts (a) and (c), as well as (b) and (c).
(f) Which control confguration provides the best control?

Y'(s) Y'(s) D'(s) 2e-20s 95s +1 0.5e-30s 60s + 1 F'(s) CAi CA Figure E15.8