Subspace Identification Methods for Modal Analysis
System identification using subspace identification methods.
Along with the functions example file is provided for the identification of 2DOF system subject to gaussian white noise excitation with added uncertainty (also gaussian white noise) to both excitation and response.
Stochastic Subspace Identification(SSI)
function [Result]=SSI(output,fs,cut)
Input:
output: output data of size (No. output channels, No. of data)
fs: Sampling frequency
cut: cutoff value=2*no of modes
Outputs :
Result : A structure consist of the below components
Parameters : NaFreq : Natural frequencies vector
DampRatio : Damping ratios vector
ModeShape : Mode shape matrix
Matrices A,C: Discrete A and C matrices
-----------------------------------
Deterministic Subspace Identification(DSI)
function [Result]=DSI(output,input,fs,cut)
Input:
output: output data of size (No. output channels, No. of data)
input: input data of size (No. input channels, No. of data)
fs: Sampling frequency
cut: cutoff value=2*no of modes
Outputs :
Result : A structure consist of the below components
Parameters : NaFreq : Natural frequencies vector
DampRatio : Damping ratios vector
ModeShape : Mode shape matrix
Matrices A,B,C,D: Discrete A,B,C and D matrices
-----------------------------------
Deterministic Stochastic Subspace Identification(DSSI)
function [Result]=DSSI(output,input,fs,cut)
Input:
output: output data of size (No. output channels, No. of data)
input: input data of size (No. input channels, No. of data)
fs: Sampling frequency
cut: cutoff value=2*no of modes
Outputs :
Result : A structure consist of the below components
Parameters : NaFreq : Natural frequencies vector
DampRatio : Damping ratios vector
ModeShape : Mode shape matrix
Matrices A,B,C,D: Discrete A,B,C and D matrices
References:
-----------------
Van Overschee, Peter, and B. L. De Moor. Subspace identification for linear systems: Theory—Implementation—Applications. Springer Science & Business Media, 2012.
Cite As
Ayad Al-Rumaithi (2024). Subspace Identification Methods for Modal Analysis (https://www.mathworks.com/matlabcentral/fileexchange/69502-subspace-identification-methods-for-modal-analysis), MATLAB Central File Exchange. Retrieved .
MATLAB Release Compatibility
Platform Compatibility
Windows macOS LinuxCategories
Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!Discover Live Editor
Create scripts with code, output, and formatted text in a single executable document.