Simulink Control Design™ - MathWorks

Trim Plant at Design Points

Suppose that you want to control this plant at a range of Cr values from 4 to 8. Trim the

model to find steady-state operating points for a set of values in this range. These values

are the design points for tuning.

Cr = (4:8)'; % concentrations

for k=1:length(Cr)

opspec = operspec(mdl_OL);

% Set desired residual concentration

opspec.Outputs(1).y = Cr(k);

opspec.Outputs(1).Known = true;

% Compute equilibrium condition

[op(k),report(k)] = findop(mdl_OL,opspec,findopOptions('DisplayReport','off'));

end

op is an array of steady-state operating points. For more information about steady-state

operating points, see “About Operating Points” on page 1-3.

Linearize at Design Points

Linearizing the plant model using op returns an array of LTI models, each linearized at

the corresponding design point.

G = linearize(mdl_OL,'rct_CSTR_OL/CSTR',op);

11 Gain-Scheduled Controllers