User`s guide

3 Linear Model Identification
How to Compute Re
sponse Values
You can use impul
se
and step commands with output arguments to get
the num erical im
pulse- and step-resp on se vectorsasafunctionoftime,
respectively.
To get the numer
ical response values:
1 Compute the FIR
model by applying either
impulse or step commands
on the data, as d
escribed in “How to Estimate Correlation Models at the
Command Line” o
npage3-16.
2 Applythefollowingsyntaxontheresultingmodel:
% To compute impulse-response data
[y,t,ysd] = impulse(model)
% To compute step-response da ta
[y,t,ysd] = step(model)
where y istheresponsedata,t is the time vector, an d ysd is the standard
deviations of the response.
How to Identify Delay Using Transient-Response Plots
You can use transient-response plots to estimate the input delay, or dea d
time, of linear systems. Input delay represents the time it takes for the output
to respond to the input.
In th e System Identification Tool GUI. To view the transient response
plot, select the Transient resp check box in the System Identification Tool
GUI. For example, the following stepresponseplotshowsatimedelayof
about 0.25 s before the system responds to the input.
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