User`s guide

5 ODE P ara meter Estimation (Grey-Box Modeling)
Use the following syntax to define an idgrey model object based on the heatd
M-file:
m = idgrey('heatd',[0.27 1],' c',[ 10,1,22])
This command specifies the auxiliary parameters as inputs to the function,
include the model order
10, the rod length of 1 meter, and an initial
temperature of
22 degrees Celsius. The comm and also s pe cifies the initial
values fo r heat conductiv ity as
0.27, and for the heat transfer coefficient as 1.
For given
data,youcanusepem to estimate the grey-box parameter values:
me = pem(data,m)
The following command shows how you can specify to estimate a new mo de l
with different auxiliary variables directly in the estimator command:
me = pem(data,m,'FileArgument',[20,1,22])
This syntax uses the FileArgument m odel property to specify a finer grid
using a larger value for
Ngrid. For more information about linear grey-box
model properties, see the
idgrey reference page.
Example – Estimating a Discrete-Time Grey-Box
Model with Parameterized Disturbance
Thisexampleshowshowtocreateasingle-input and s ingle-output grey-box
model structure when you know the variance of the measurement noise. The
code in this exam ple u se s the Co ntro l System Toolbox command
kalman for
computing the Kalman gain from the known and estimated noise variance.
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