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Indexed by:Journal Papers

Date of Publication:2015-10-01

Journal:APPLIED OCEAN RESEARCH

Included Journals:SCIE、EI、Scopus

Volume:53

Page Number:250-256

ISSN No.:0141-1187

Key Words:Modal parameter; Time-varying system; Single point mooring; Empirical mode decomposition; Time-varying autoregressive

Abstract:A method based on empirical mode decomposition (EMD) and time-varying autoregressive (WAR) model is proposed here to identify the modal parameters of time-varying systems, such as the Floating Production Storage and Offloading (FPSO) single point mooring system. For the EMD-TVAR method, the original signal is decomposed into a finite number of 'intrinsic mode functions' (IMFs) by the EMD. Each IMF can be represented as a WAR model. Then, the time-varying modal parameters i.e., instantaneous frequency(IF) and modal dumping, can be obtained by the basis functions expansion method. The proposed EMD-TVAR method has good results in two experiments compared with the Huang-Hilbert transformation and Short Time Fourier Transform method, and it has been used to analysis the modal parameters of FPSO single point mooring system successfully. The system's time-varying characteristic and its frequency distribution can be known from the modal analysis results. (C) 2015 Elsevier Ltd. All rights reserved.