Specifications

3 Operations on LTI Models
3-16
Model Interconnection Functions
The Control System Toolbox provides a number of functions to help with the
model building process. These include model interconnection functions to
perform I/O concatenation (
[,], [;],andappend), general parallel and series
connections (
parallel and series), and feedback connections (feedback and
lft). These functions are useful to model open- and closed-loop systems.
Concatenation of LTI Models
LTI model concatenation is done in a manner similar to the way you
concatenate matrices in MATLAB, using
sys = [sys1 , sys2]% horizontal concatenation
sys = [sys1 ; sys2]% vertical concatenation
Interconnection Operator Description
[,]
Concatenates horizontally
[;]
Concatenates vertically
append
Appends models in a block diagonal
configuration
augstate
Augments the output by appending states
connect
Forms an SS model from a block diagonal
LTI object for an arbitrary interconnection
matrix
feedback
Forms the feedback interconnection of two
models
lft
Produces the LFT interconnection
(Redheffer Star product) of two models
parallel
Forms the generalized parallel connection
of two models
series
Forms the generalized series connection of
two models