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how to get the parameters of step response?
To elaborate on what Ryan wrote, suppose y is the vector of step response data and Ts is the sampling time. N = length(y); ...

13 years ago | 0

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fitting a transfer function from acquired data with tfest
What do you mean by "nominator"? N or D? Note that IDTF creates transfer functions that have a monic polynomial for the denomina...

13 years ago | 0

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How to determine the order of ARMA and AR coefficient ?
One way would be to state-space estimation which lets you inspect the Hankel singular values for model order: % pick optimal ...

13 years ago | 0

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Button Callback for System Identification Tool
yes, that should work; give it a try.

13 years ago | 0

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How to show the power spectral density of a time-domain arx model in System Identification Toolbox?
For frequency response of the model (H(w) = B(w)/A(w)), use FREQRESP or BODE command, as in: H = freqresp(m, w); or [Magnitude, ...

13 years ago | 0

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Answered
How to get the coefficients from a nlarx model constructed using System Identification Toolbox?
The coefficients of the nonlinear arx model are stored in the property called "Nonlinearity". In particular, look at m2.Nonlinea...

13 years ago | 0

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Need help with difference equation (continuous-time system)
[y,t] = step(tf(1,[1 5 6]))

13 years ago | 1

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Answered
observability staircase form for MIMO system
OBSV reference page has this tip: obsv is here for educational purposes and is not recommended for serious control design. Co...

13 years ago | 0

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Problem with System Identification Toolbox and 'sim' command
Some questions and comments: 1. What kind of nonlinear model did you create? If it was a nonlinear ARX model (idnlarx), what ...

13 years ago | 2

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system identification procedure
Have Simulink data available in MATLAB workspace as double vectors. In the GUI (ident) import time signals to load the data. The...

13 years ago | 1

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Answered
n-step prediction in simulink
You will need to implement a predictor model in Simulink. You can "convert" an estimated idss model into a predictor model. Supp...

13 years ago | 0

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lost access to tf and ss from id toolbox
It seems Control System Toolbox is not available to you anymore. What do you get when you type "ver control" in MATLAB?

13 years ago | 1

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Transfer functions of data
If I understood the question, you want the transfer function between input, recorded in the second column, against y which is re...

13 years ago | 0

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System Identification model validation failure!
What initial conditions did you use in Simulink block? The GUI estimates the initial states to maximize the fit to data. If you ...

13 years ago | 0

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specifying state space models in SysID toolbox
See KALMAN (Control System Toolbox). It lets you compute the observer matrix K required by IDSS model form, as a function of R, ...

13 years ago | 0

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ssest function - identification toolbox
Hi Alex, Could you post some more details? When you originally created the model object (idss(A,B,C,D)), what were the sizes ...

13 years ago | 0

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How to obtain State space model response ?
see LSIM

13 years ago | 1

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PEM grey box using merged data.
It is the latter - one combined estimation using both sets of data. If you parametrize initial states x0 (like you do in your sy...

13 years ago | 0

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Answered
How to make transfer function if you know input/output data
Have you tried tfest? http://www.mathworks.com/help/ident/ref/tfest.html

13 years ago | 0

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nlarx model?? how to simulate in simulink
This might be owing to initial conditions. In the GUI and in the COMPARE function, the fit is computed by *estimating* the initi...

13 years ago | 2

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Simplified model parameter estimation
Try the various linear and nonlinear model identification tools in the System Identification Toolbox product. There are dedicate...

13 years ago | 0

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Is there a function in matlab that finds a transmition function of a filter, based on the input and output signals?
See various model estimation functions in System Identification Toolbox such as pem, n4sid, oe, tfest, procest, ssest (the latte...

13 years ago | 0

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System Identification Tool: Using a script to load Systems to the ident tool
No, there is none. If you have saved a GUI session (.sid file) with certain systems and datasets, you can load that session by t...

13 years ago | 0

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Dealing with NaN in idnlgrey
Missing data cannot be directly handled by an estimation routine. You must "fix" your data appropriately in advance. Some things...

13 years ago | 0

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System Identification
Try estimation functions such as OE, ARX, N4SID and PEM in releases R2011b and older. In R2012a you can also try TFEST, SSEST, P...

13 years ago | 0

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Answered
ARMA model for temperature simulation
See SIM and SIMSD functions in System Identification Toolbox. When using SIM, add the 'noise' qualifier as input argument to...

13 years ago | 0

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Help using structures for idss initial system
Coefficient dependence is beyond the scope of idss model structure. Use idgrey model type instead, where in you write a MATLAB f...

13 years ago | 0

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how to import variables in my workspace into system identification toolbox
This hsppens when the expressions you entered for input snd output variables cannot be successfully evaluated in the base worksp...

13 years ago | 0

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Using estimated transfer function which has estimated through tfestimate !
You need a parametric transfer function (that delivers numerator/denominator polynomials) estimator. See: http://www.mathw...

13 years ago | 0

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Finding the Trasfer Function !
If you have System Identification Toolbox, you could try directly estimating the transfer function (b/a) using input/output data...

13 years ago | 0