Extract continuous-time linear state-space model around operating point
Name of the Simulink® system from which the linear model is extracted.
x = Simulink.BlockDiagram.getInitialState('sys');
can then change the operating point values within this structure by
If the state
contains different data types (for example,
A three-element vector of optional arguments:
The perturbation values used to perform the perturbation of all the states and inputs of the model. The default values are
xpert = para(1) + 1e-3*para(1)*abs(x) upert = para(1) + 1e-3*para(1)*abs(u)
When a model has model references using the Model block, you must use the Simulink structure
format to specify
xpert = Simulink.BlockDiagram.getInitialState('sys');
can then change the perturbation values within this structure by editing
perturbation input arguments are only available when invoking the
perturbation algorithm created prior to MATLAB® 5.3, either by
linmodv5 provides only basic linearization functionality. For full
linearization functionality, use Simulink
Control Design™ software. For more information, see Choose Linearization Tools (Simulink Control Design).
linmodv5 computes a linear state space model
using the full model perturbation algorithm created prior to MATLAB 5.3.
linmodv5 obtains linear models from systems
of ordinary differential equations described as Simulink models.
Inputs and outputs are denoted in Simulink block diagrams using
Inport and Outport blocks.
By default, the system time is set to zero. For systems that
are dependent on time, you can set the variable
a two-element vector, where the second element is used to set the
t at which to obtain the linear model.
The ordering of the states from the nonlinear model to the linear model is maintained. For Simulink systems, a character vector variable that contains the block name associated with each state can be obtained using
[sizes,x0,xstring] = sys
xstring is a vector of strings whose ith
row is the block name associated with the
Inputs and outputs are numbered sequentially on the diagram.
For single-input multi-output systems, you can convert to transfer
function form using the routine
ss2tf or to zero-pole
ss2zp. You can also convert the linearized
models to LTI objects using
ss. This function produces
an LTI object in state-space form that can be further converted to
transfer function or zero-pole-gain form using
The default algorithms in
Transport Delay blocks by replacing the linearization of the blocks
with a Pade approximation. For the
linearization of a model that contains Derivative or Transport Delay
blocks can be troublesome. For more information, see Linearizing Models.