Note: This page has been translated by MathWorks. Please click here

To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.

To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.

Modal parameters from frequency-response functions

`fn = modalfit(frf,f,fs,mnum)`

`fn = modalfit(frf,f,fs,mnum,Name,Value)`

```
[fn,dr,ms]
= modalfit(___)
```

```
[fn,dr,ms,ofrf]
= modalfit(___)
```

`[___] = modalfit(sys,f,mnum,Name,Value)`

`[___] = modalfit(`

estimates the modal parameters of the identified model `sys`

,`f`

,`mnum`

,`Name,Value`

)`sys`

. Use
estimation commands like `ssest`

or `tfest`

to create `sys`

starting from a measured
frequency-response function or from time-domain input and output signals. This syntax
allows use of the `'DriveIndex'`

,
`'FreqRange'`

, and `'PhysFreq'`

name-value pair
arguments. It typically requires less data than syntaxes that use nonparametric
methods. You must have a System
Identification Toolbox™ license to use this syntax.

[1] Allemang, Randall J., and David L. Brown. “Experimental Modal Analysis and Dynamic Component Synthesis, Vol. III: Modal Parameter Estimation.” Technical Report AFWAL-TR-87-3069. Air Force Wright Aeronautical Laboratories, Wright-Patterson Air Force Base, OH, December 1987.

[2] Brandt, Anders. *Noise and Vibration Analysis:
Signal Analysis and Experimental Procedures*. Chichester,
UK: John Wiley & Sons, 2011.

[3] Ozdemir, Ahmet Arda, and Suat
Gumussoy. "Transfer Function Estimation in System
Identification Toolbox via Vector Fitting." *Proceedings of the 20th World Congress of the
International Federation of Automatic Control*, Toulouse, France, July
2017.

`modalfrf`

| `modalsd`

| `n4sid`

| `tfest`

| `tfestimate`

- Modal Analysis of Identified Models
- System Identification Overview (System Identification Toolbox)
- System Identification Workflow (System Identification Toolbox)
- Supported Continuous- and Discrete-Time Models (System Identification Toolbox)

Was this topic helpful?