Quality Control and Feature Restoration of High-Speed Magnetic Flux Leakage Signals based on Signal Compensation Method

Quality control of the magnetic flux leakage (MFL) signal plays a vital role in the integrity assessment of pipelines. However, most MFL detection suffers from low magnetization levels and large signal distortion due to the velocity effect. Current methods typically require the MFL tool to operate at relatively low inspection speeds, which will reduce detection efficiency. In this paper, a signal compensation method is proposed to address the issue. First, the formation mechanism of signal distortion in high-speed MFL detection is analyzed. Compared with previous studies, we find that the signal distortion is formed in two steps: longitudinal compression and oblique stretching. Second, the magnetic circuit between the MFL tool and the pipe is optimized to improve the pipe magnetization level Finally, a signal compensation method is proposed to reduce the MFL signal distortion. Results validate the superiority of the proposed method in signal feature restoration. In general, our compensation method has the potential to improve detection efficiency and signal features.