step.m

% Step test for Model 8 - Binary Distillation Column
% Created by John Hedengren

global u

% Steady State Initial Condition for the Control
u_ss = 3.0;

% Steady State Initial Conditions for the States
x_ss(1:32)=[0.93541941614016
   0.90052553715795
   0.86229645132283
   0.82169940277993
   0.77999079584355
   0.73857168629759
   0.69880490932694
   0.66184253445732
   0.62850777645505
   0.59925269993058
   0.57418567956453
   0.55314422743545
   0.53578454439850
   0.52166550959767
   0.51031495114413
   0.50127509227528
   0.49412891686784
   0.48544992019184
   0.47420248108803
   0.45980349896163
   0.44164297270225
   0.41919109776836
   0.39205549194059
   0.36024592617390
   0.32407993023343
   0.28467681591738
   0.24320921343484
   0.20181568276528
   0.16177269003094
   0.12514970961746
   0.09245832612765
   0.06458317697321];

x_ss = x_ss';

% Open Loop Step Change
u = 2.7;

% Final Time (min)
tf = 120;

[t,x] = ode15s('distill',[0 tf],x_ss);

% Parse out the distillate composition
x1 = x(:,1);

% Plot the results
figure(1);
plot(t,x1);