Time–Frequency Extraction Model Based on Variational Mode Decomposition and Hilbert–Huang Transform for Offshore Oil Platforms Using MIMU Data

Time–frequency extraction is a key issue to understand structural symmetry of dynamic responses offshore oil platforms for early warning during drilling operations. Current popular methods signal characteristics can only obtain the attributes with single dimension or poor precision. To solve this, combined Hilbert–Huang transform (HHT) and variational mode decomposition (VMD) method proposed extract multidimensional response time, frequency, energy platforms. Based on extracted time–frequency–energy information, frequency-domain integration approach (FDIA) be applied calculate displacement using accelerometer in micro inertial measurement unit (MIMU). A complementary filtering algorithm was designed measure torsion angle six degrees freedom data from MIMU information. The performance validated series simulation shaking-table tests field test conducted an platform at Dongying City, Shandong Province, China. During test, seven out eight collisions were detected frequency range 5 Hz 12 Hz. intensity fifth collision highest, maximum obtained by 6 mm. In addition, results show correlation between axes gyroscope, their combination up 1.1°.