User`s guide

2 LTI Models
2-52
The resulting model is displayed as
Transfer function from input to output...
1
#1: exp(–0.1*s) * -
s
2
#2: exp(–0.1*s) * -----
s + 1
By comparison, to produce an equivalent transfer function using the
ioDelayMatrix property, you would need to type
H = [1/s ; 2/(s+1)];
H.iodelay = [0.1 ; 0.1];
Notice that the0.1 second delay is repeated twiceinthe I/O delay matrix. More
generally, for a TF, ZPK, or FRD model with input delays and
output delays , the equivalent I/O delay matrix is
Specifying Delays in Discrete-Time Models
You can also use the ioDelayMatrix, InputDelay,andOutputDelay properties
to specify delays in discrete-time LTI models. You specify time delays in
discrete-time models withintegermultiples ofthe samplingperiod.Theinteger
k you supply for the time delay of a discrete-time model specifies a time delay
of k sampling periods. Such a delay contributes a factor to the transfer
function.
For example,
h = tf(1,[1 0.5 0.2],0.1,'inputdelay',3)
α
1
...
α
m
,,[]
β
1
...
β
p
,,[]
α
1
β
1
+α
2
β
1
+... α
m
β
1
+
α
1
β
2
+ α
2
β
2
+ α
m
β
2
+
:: :
α
1
β
p
+α
2
β
p
+... α
m
β
p
+
z
k
–