User`s guide

2 LTI Models
2-46
• Interconnections of continuous-time delay systems as long a s the resulting
transfer function from input to output is of t he form
where is a rational function of
• Padé approximation of time delays (
pade)
Specifying Input/Output Delays
Using the ioDelayMatrix property, you can specify frequency-domain models
with independent delays in each entry of the transfer function. In continuous
time, such models have a transfer function of the form
where the ’s are rational functions of , and is the time delay between
input andoutput . See “Specifying Delaysin Discrete-TimeModels”on page
2-52 for details on the discrete-time counterpart. We collectively refer to the
scalars as the I/O delays.
The syntax to create above is
H = tf(num,den,'iodelaymatrix',Tau)
or
H = zpk(z,p,k,'iodelaymatrix',Tau)
where
•
num,den (respectively,z,p,k)specify the rationalpart ofthe transfer
function
•
Tau is the matrix of time delays for each I/O pair. That is, Tau(i,j) specifies
the I/O delay in seconds. Note that
Tau and should have the same
row and column dimensions.
You can also use the
ioDelayMatrix property in conjunction with state-space
models, as in
sys = ss(A,B,C,D,'iodelaymatrix',Tau)
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