Simulink Control Design™ - MathWorks

r K y

+

• e

G

u

Loop transfer

Controller Plant

Here, at e, the software adds a linearization output, inserts a loop break, and adds a

linearization input, de. The loop transfer function at e, L, is the transfer function from de

to e. L is calculated as follows:

e=−︸GK

L

de.

To compute -KG, use u as the analysis point for getLoopTransfer.

The software does not modify the Simulink model when it computes the loop transfer

function.

Analysis Points

Analysis points, used by the slLinearizer and slTuner interfaces, identify locations

within a model that are relevant for linear analysis and control system tuning. You use

analysis points as inputs to the linearization commands, such as getIOTransfer,

getLoopTransfer, getSensitivity, and getCompSensitivity. As inputs to the

linearization commands, analysis points can specify any open-loop or closed-loop transfer

function in a model. You can also use analysis points to specify design requirements when

tuning control systems using commands such as systune.

Location refers to a specific block output port within a model or to a bus element in such

an output port. For convenience, you can use the name of the signal that originates from

this port to refer to an analysis point.

You can add analysis points to an slLinearizer or slTuner interface, s, when you

create the interface. For example:

s = slLinearizer('scdcascade',{'u1','y1'});

Alternatively, you can use the addPoint command.

15 Alphabetical List