User`s guide

4 Arrays of LTI Models
4-2
Introduction
You can use LTI arrays to collect a set of LTI models into a single MATLAB
variable. You then use this variable to manipulate or analyze the entire
collection of models in a vectorized fashion. You access the individual models
in the collection through indexing rather than by individual model names.
LTI arrays extend the concept of single LTI models in a similar way to how
multidimensional arrays extend two-dimensional matrices in MATLAB (see
Chapter 12, “Multidimensional Arrays” in Using M ATLAB). Additionally,
whenyouthinkaboutLTIarrays,itisusefultokeepinmindthematrix
interpretation of LTI models developed in “Viewing LTI Systems As Matrices”
on page 2-5.
When to Collect a Set of Models in an LTI Array
You can use L T I arrays to represent:
• A set of LTI models arising from the linearization of a nonlinear system at
several o perating points
• A collection of transfer f unctions that depend on one or more parameters
• A set of LTI models arising from several system identification experim ents
applied to one plant
• A set of gai n- sched uled LTI controlle rs
• A list of LTI models you want to collect together under the same name
Restrictions for LTI Models Collected in an Array
For each model in an LTI array, the following properties must be t he same:
• The number of inputs and outputs
• The sample time, for discrete-time models
• The I/O names and I/O groups
Note: You cannot specify Simul ink LTI blocks w ith LTI arrays.