Controlling low frequency waves for marine vibrator system with a closed-loop feedback control scheme

Abstract

Low-frequency amplitude attenuation is one of the major challenges affecting the performance of marine electromagnetic-controlled seismic sources. To address this issue, we propose a closed-loop feedback compensation scheme based on real-time hydrophone measurements, in which the excitation signal is dynamically regulated to compensate for output variations caused by system nonlinearities and external disturbances. The proposed scheme is implemented on a computer-controlled platform integrating sweep signal generation, signal processing, electromagnetic excitation, and data acquisition modules, enabling real-time feedback control of the marine vibrator. Mathematical analysis and laboratory experiments demonstrate that the proposed method effectively improves output amplitude stability and suppresses harmonic distortion over the operating frequency range of 30–200 Hz. In particular, the feedback control significantly enhances output consistency in the lower-frequency portion of the operating bandwidth while maintaining stable performance across the investigated frequency range. These results indicate that the proposed closed-loop feedback compensation scheme provides an effective and practical solution for improving the performance and reliability of marine electromagnetic-controlled seismic sources.