Modal parameter identification via robust second-order blind identification method

A robust second-order statistical method employed in blind source separation (BSS) was presented for use in modal parameter identification. Firstly, modal responses were estimated by the application of robust second-order blind identification(R-SOBI) technique on the measured vibration signals. And then, modal shapes were extracted from the de-mixing matrix above. Finally, frequency and damping ratios could be obtained from the modal responses using each single degree of freedom mode. Numerical results demonstrated that the proposed method provides a novel and robust approach to modal identification; especially, the modal shapes can be extracted exactly even in lower signal to noise ratio (SNR) case.