Simulink Control Design™ - MathWorks

(^2) Design a family of linear controllers, such as PID controllers, for the plant models
obtained in the previous step.
(^3) Implement a scheduling mechanism such that the controller coefficients, such as PID
gains, are changed based on the values of the scheduling variables. Smooth
(bumpless) transfer between controllers is required to minimize disturbance to plant
operation.
4 Assess control performance with simulation.
For more information on gain scheduling, see [2].
This example focuses on designing a family of PID controllers for the nonlinear CSTR
plant.
Obtain Linear Plant Models for Multiple Operating Points
The output concentration C is used to identify different operating regions. The CSTR plant
can operate at any conversion rate between a low conversion rate (C = 9 ) and a high
conversion rate (C = 2 ). In this example, divide the operating range into eight regions
represented by C = 2 through 9.
Specify the operating regions.
C = [2 3 4 5 6 7 8 9];
Create an array of default operating point specifications.
op = operspec(mdl,numel(C));
Initialize the operating point specifications by specifying that the output concentration is
a known value, and specifying the output concentration value.
for ct = 1:numel(C)
op(ct).Outputs.Known = true;
op(ct).Outputs.y = C(ct);
end
Compute the equilibrium operating points corresponding to the values of C.
opoint = findop(mdl,op,findopOptions('DisplayReport','off'));
Linearize the plant at these operating points.
Plants = linearize(mdl,opoint);
7 PID Controller Tuning