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Rajiv Singh

MathWorks

Last seen: 10 dagen ago Active since 2011

Interested in System Identification, Control System Design, Machine Learning, Optimization, Predictive Maintenance

Programming Languages:
Python, C, Java, PHP, R, MATLAB, SQL, HTML, Perl, Fortran
Spoken Languages:
English, Hindi
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Answered
How can I set nonlinear constraints in a nonlinear grey-box model?
Linear or nonlinear constraints are not supported in nlgreyest directly. Depending upon the problem, you can sometimes get away ...

10 dagen ago | 0

Answered
How does Matlab System Identification Tool estimate Transfer Fcts?
See the tfest reference page, Algorithms and References sections.

ongeveer een maand ago | 0

Answered
Online Parameter Indentification of SIMO System in Simulink
There is no multi-output recursive estimator available today in System Identification Toolbox; this is a limitation. What you ne...

ongeveer 2 maanden ago | 0

Answered
Obtain transfer function from (noisy) measurement data and use this transfer function for control in simulink
Automatic order determination is not easy/trivial in general. The closest we have to this is automatic selection of state-space ...

ongeveer 2 maanden ago | 0

Answered
How to use arxstruc with multiple input multiple output ( MIMO ) systems?
The order combinations accepted by arxstruc can be generated by using the STRUC command; see: Generate model-order combinations ...

ongeveer 2 maanden ago | 1

Answered
Mutivariate regression using Regression Learner App
I would recommend looking at the System Identification Toolbox. It provides many functions for performing linear and nonlinear r...

ongeveer 2 maanden ago | 0

Answered
Transfer Function Models in the System Identification App
The name "Transfer function" is reserved for linear transfer functions (equivalently, linear ODEs) in System Identification Tool...

ongeveer 2 maanden ago | 0

Answered
Output of Transfer Function in Sys ID App not the same as workspace
In addition to the input, you need to ensure that you are using the same initial conditions. See: Estimate Initial Conditions f...

ongeveer 2 maanden ago | 0

Answered
How to develop multi variation equation
+1 on Walter Roberson's comments. In the dynamic system modeling area, the additional information, or assumption, rquired is th...

ongeveer 2 maanden ago | 0

Answered
MOESP algorithm by using n4sid command for discrete time data
The issue is not with the sample time choice but with the system itself. It seems that the data from a system with undamped pole...

ongeveer 2 maanden ago | 0

Answered
Using System Identification Toolbox More Effectively
If you have input and output signals separately, you will need to filter both identically, so that in the resulting transfer fun...

ongeveer 2 maanden ago | 1

Answered
parameter optimization in function
See also Classical Pendulum: Some Algorithm-Related Issues - MATLAB & Simulink Example (mathworks.com)

ongeveer 2 maanden ago | 0

Answered
Simulated and predicted response of time-series idnlgrey model in Matlab
IDNLGREY is an "output-error" model, that is, the noise affacts only the output measurements and not the state updates. Hence th...

3 maanden ago | 0

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Answered
How to train a neural-network-based NARX model with multiple time series, each corresponding to a different value of a control parameter (to be included as additional input)
This use case/requirement seems like an extension of linear parameter varying modeling (LPV) framework.There is a certain parame...

3 maanden ago | 0

Answered
Trying to simulate NLARX model in Simulink throws an error
This appears to be a bug. Please reach out to technical support or use the "Report a bug" link on Bugs Existing in R2022a | Bug ...

4 maanden ago | 0

Answered
Data analysis from measurements (PRBS injected to a system -> how to plot the bode of the system response)
This could be seen as an exercise in system identification. Use functions like TFEST,SSEST, ARX to fit a model to the (u,y) data...

4 maanden ago | 0

Answered
How to use chi2gof in system identification white residual test?
The approach looks fine to me in principle, hard to say more without looking at the data. One thing you can try is call RESID wi...

4 maanden ago | 0

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Answered
Can you please provide a general explanation of how the algorithm implemented in the SSEST function works?
ssest contains multiple algorithms for fitting time- and frequency domain data. Roughtly speaking the time-domain identification...

4 maanden ago | 0

Answered
LOES of a high order state space model
You could attempt this in frequency domain. G = frd(OriginalModel,w) % w is a suitably chosen frequency grid ReducedModel = ss...

ongeveer 2 jaar ago | 1

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Answered
How to build a single input multiple output ARX or ARMAX model with MATLAB
Identification routines want variables to be arranged along the columns, time along rows. Your data "y" is transposed. Also, the...

ongeveer 2 jaar ago | 0

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Answered
Use of modalfrf for operating measurements
This is essentially a system identification problem. You have non-parametric (tfestimate, spa, spafdr, etfe) techniques and para...

ongeveer 2 jaar ago | 0

| accepted

Answered
How to remove delay from idtf object?
You will need an invertible realization. Try high order transfer function estimations with no delays. Or, if the estimated model...

ongeveer 2 jaar ago | 0

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Answered
Testing different optimization methods on a state space model by solving ODEs
The closest infrastructure to this style of numerical optimization approach is "grey box identification". See idgrey, idnlgrey, ...

ongeveer 2 jaar ago | 0

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Answered
nlarx model initial conditions
You can prefix estimation data (both input and output signals) with nd zeros, where nd = maximum lag in the model. Initial condi...

ongeveer 2 jaar ago | 0

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Answered
How to force tfest to estimate the process with "only real poles" ?
TFEST cannot guarantee real poles. If you can work with <=3 poles and <=1 zero, try PROCEST. This is a process model estimator...

ongeveer 2 jaar ago | 3

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Answered
What is the difference between FRD and IDFRD
Both FRD and IDFRD are used to store Freqyency Response Data, that is, the complex frequency response vector (Mag.*exp(i*Phase))...

ongeveer 2 jaar ago | 1

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Answered
How to estimate the parameter in a customized transfer function
Grey-box identification is an option. You will need to write a function that takes K0 and a0 as inputs, and returns state-space ...

ongeveer 2 jaar ago | 0

Answered
Minimum input data resolution
Look up Nyquist Sampling Theorem. If you are sampling (hopefully with anti-aliasing) at 1Hz then you cannot theoretically captur...

ongeveer 2 jaar ago | 0

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Answered
Well-identified fitted process model does not behave like data on simulink
You are almost there. Convert the model into state-space form and use it for simulation. For initial conditions, you will need t...

ongeveer 2 jaar ago | 0

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Answered
How to calculate the transfer function for a 16 input system?
Try also TFEST. Although you might want to reduce the number of inputs by PCA or PLS analysis.

ongeveer 2 jaar ago | 0

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