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How can I get polynomials for MIMO case using iv4?
ARX does work for MIMO case. So does IV4. Can you post an example?

oltre 13 anni fa | 0

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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); ...

oltre 13 anni fa | 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...

oltre 13 anni fa | 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 ...

oltre 13 anni fa | 0

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

oltre 13 anni fa | 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, ...

oltre 13 anni fa | 0

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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...

quasi 14 anni fa | 0

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

quasi 14 anni fa | 1

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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...

quasi 14 anni fa | 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 ...

quasi 14 anni fa | 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...

quasi 14 anni fa | 1

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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...

quasi 14 anni fa | 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?

quasi 14 anni fa | 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...

quasi 14 anni fa | 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 ...

quasi 14 anni fa | 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, ...

quasi 14 anni fa | 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 ...

quasi 14 anni fa | 0

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How to obtain State space model response ?
see LSIM

quasi 14 anni fa | 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...

quasi 14 anni fa | 0

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

quasi 14 anni fa | 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...

circa 14 anni fa | 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...

circa 14 anni fa | 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...

circa 14 anni fa | 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...

circa 14 anni fa | 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...

circa 14 anni fa | 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...

circa 14 anni fa | 0

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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...

circa 14 anni fa | 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...

circa 14 anni fa | 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...

circa 14 anni fa | 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...

circa 14 anni fa | 0