Simulink Control Design™ - MathWorks

Analyze Command-Line Batch Linearization Results

Using Response Plots

This example shows how to plot and analyze the step response for batch linearization

results obtained at the command line. The term batch linearization results refers to the

ss model array returned by the slLinearizer interface or linearize function. This

array contains linearizations for varying parameter values, operating points, or both, such

as illustrated in “Batch Linearize Model for Parameter Variations at Single Operating

Point” on page 3-20 and “Vary Operating Points and Obtain Multiple Transfer Functions

Using slLinearizer Interface” on page 3-41. You can use the techniques illustrated in this

example to analyze the frequency response, stability, or sensitivity for batch linearization

results.

Obtain Batch Linearization Results

Load the batch linearization results saved in scd_batch_lin_results1.mat.

The following code obtains linearizations of the watertank model for four simulation

snapshot times, t = [0 1 2 3]. At each snapshot time, the model parameters, A and b,

are varied. The sample values for A are [10 20 30], and the sample values for b are [4

6]. The slLinearizer interface includes analysis points at the reference signal and

plant output.

open_system('watertank')

sllin = slLinearizer('watertank',{'watertank/Desired Water Level',...

'watertank/Water-Tank System'})

[A_grid,b_grid] = ndgrid([10,20,30],[4 6]);

params(1).Name = 'A';

params(1).Value = A_grid;

params(2).Name = 'b';

params(2).Value = b_grid;

sllin.Parameters = params;

sllin.OperatingPoints = [0,1,2,3];

linsys = getIOTransfer(sllin,'Desired Water Level','Water-Tank System');

linsys, a 4-by-3-by-2 ss model array, contains the closed-loop transfer function of the

linearized watertank model from the reference input to the plant output. The operating

point varies along the first array dimension of linsys, and the parameters A and b vary

along the second and third dimensions, respectively.

3 Batch Linearization