The Discrete State Space (or State Space) component defines the relation between the input and the output in state-space form,

$x\=A\mathrm{pre}\left(x\right)\+Bu$

$y\=C\mathrm{pre}\left(x\right)\+\mathrm{D}u$

where $\mathrm{pre}\left(x\right)$ is the value of the discrete state $x$ at the previous sample time instant.

The input is a vector of length $\mathrm{\nu }$, the output is a vector of the length $\mathrm{ny}$, and $\mathrm{nx}$ is the number of states. Accordingly,

$A$ has the dimension: $A\left(\mathrm{nx}\,\mathrm{nx}\right)$,

$B$ has the dimension: $B\left(\mathrm{nx}\,\mathrm{\nu }\right)$,

$C$ has the dimension: $C\left(\mathrm{ny}\,\mathrm{nx}\right)$,

$\mathrm{D}$ has the dimension: $\mathrm{D}\left(\mathrm{ny}\,\mathrm{\nu }\right)$

The dimensions of the state-space matrices specified in parameters $A$, $B$, $C$, and $\mathrm{D}$ need to be adjusted according to the number of inputs that you provide. To change the dimensions of a matrix in a parameter field, right-click (Control-click for Mac) the parameter field and select Edit Matrix Dimensions. You can then specify the number of rows and columns to include in the matrix.

Note: The context menu operation for setting the matrix dimension is not available if the parameter field is blank. In this case, you must enter a matrix as a list of lists, for example, [[1,2],[3,4]].

The component described in this topic is from the Modelica Standard Library. To view the original documentation, which includes author and copyright information, click here.