sparss
Description
Use sparss
to represent sparse descriptor state-space models
using matrices obtained from your finite element analysis (FEA) package. FEA involves the
concept of dynamic substructuring where a mechanical system is partitioned into components
that are modeled separately. These components are then coupled using rigid or semi-rigid
physical interfaces that express consistency of displacements and equilibrium of internal
forces. The resultant matrices from this type of modeling are quite large with a sparse
pattern. Hence, using sparss
is an efficient way to represent such large
sparse state-space models in MATLAB® to perform linear analysis. You can also use sparss
to
convert a second-order mechss
model object to a sparss
object.
You can use sparss
model objects to represent SISO or MIMO state-space
models in continuous time or discrete time. In continuous time, a first-order sparse
state-space model is represented in the following form:
Here, x
, u
and y
represent the states, inputs and outputs respectively, while A
,
B
, C
, D
and E
are the state-space matrices. The sparss
object represents a state-space
model in MATLAB storing sparse matrices A
, B
,
C
, D
and E
along with other
information such as sample time, names and delays specific to the inputs and outputs.
You can use a sparss
object to:
Perform time-domain and frequency-domain response analysis.
Specify signal-based connections with other LTI models.
Transform models between continuous-time and discrete-time representations.
Find low-order approximations of large sparse models.
For more information, see Sparse Model Basics.
Creation
Syntax
Description
creates a continuous-time first-order sparse state-space model object of the following form:sys
= sparss(A
,B
,C
,D
,E
)
For instance, consider a plant with Nx
states,
Ny
outputs, and Nu
inputs. The first-order
state-space matrices are:
A
is the sparse state matrix withNx
-by-Nx
real- or complex-values.B
is the sparse input-to-state matrix withNx
-by-Nu
real- or complex-values.is the sparse state-to-output matrix with
Ny
-by-Nx
real- or complex-values.D
is the sparse gain or input-to-output matrix withNy
-by-Nu
real- or complex-values.E
is the sparse mass matrix with the same size as matrixA
. WhenE
is omitted,sparss
populatesE
with an identity matrix.
Input Arguments
Output Arguments
Properties
Object Functions
The following lists show functions you can use with sparss
model
objects.
Examples
References
[1] M. Hosea and L. Shampine. "Analysis and implementation of TR-BDF2." Applied Numerical Mathematics, vol. 20, no. 1-2, pp. 21-37, 1996.
Version History
Introduced in R2020bSee Also
sparssdata
| mechss
| showStateInfo
| xsort
| full
| getx0
| spy
| Descriptor
State-Space (Simulink)