Use getIOTransfer to access and plot the closed-loop responses from reference and
disturbance to the tops and bottoms concentrations. The tuned responses show a good
compromise between tracking and disturbance rejection.
figure
Ttrack = getIOTransfer(ST,'r','y');
step(Ttrack,40), grid, title('Setpoint tracking')
Treject = getIOTransfer(ST,{'dV','dL'},'y');
step(Treject,40), grid, title('Disturbance rejection')
Decoupling Controller for a Distillation Column