This paper considers the problem of noise cancellation for the magnetic flux leakage (MFL) data obtained from the inspection of oil pipelines. MFL data is contaminated by various sources of noise, and the noise can co...This paper considers the problem of noise cancellation for the magnetic flux leakage (MFL) data obtained from the inspection of oil pipelines. MFL data is contaminated by various sources of noise, and the noise can considerably reduce the detectability of flaw signals in MFL data. This paper presents a new de-noising approach for removing the system noise contained in the MFL data by using the coefficients de-noising with wavelet transform. Experimental results are presented to demonstrate the advantages of this de-noising approach over the conventional wavelet de-noising method.展开更多
Sensing sensitivity is the key performance of optical tweezers.By adjusting the frequency and magnitude of an applied Coulomb force as an input of optical tweezers,we directly measured the sensitivity and signal-to-no...Sensing sensitivity is the key performance of optical tweezers.By adjusting the frequency and magnitude of an applied Coulomb force as an input of optical tweezers,we directly measured the sensitivity and signal-to-noise ratio(SNR)of a system and indirectly calculated the actual noise magnitude.Combined with an output filter,the relationship between the SNR and bandwidths was studied.We established the simulation model of a system using Simulink and simulated the relationship between the SNR and magnitude of the input forces and filter bandwidths.In addition,we built an experimental system to determine the relationship between the SNR and the magnitude of the input forces and filter bandwidths.The actual minimum detectable force was measured as 1.8275×10^(-17)N at a 1Hz bandwidth.The experimental results were correlated with the simulation and theoretical results,confirming the effectiveness of the proposed method and demonstrating the high sensitivity of vacuum optical tweezers as mechanical sensors.We proposed a novel method of calibration and measurement of system sensing parameters by applying an actual force that was more direct and precise than the theoretical calculation method that requires accurate fitting parameters,such as the particle radius and density.This method can be employed to analyze the system noise and phase characteristics to confirm and improve the real performance of the system.展开更多
文摘This paper considers the problem of noise cancellation for the magnetic flux leakage (MFL) data obtained from the inspection of oil pipelines. MFL data is contaminated by various sources of noise, and the noise can considerably reduce the detectability of flaw signals in MFL data. This paper presents a new de-noising approach for removing the system noise contained in the MFL data by using the coefficients de-noising with wavelet transform. Experimental results are presented to demonstrate the advantages of this de-noising approach over the conventional wavelet de-noising method.
基金supported by the National Natural Science Foundation of China(Grant Nos.62075193,11304282,and 61601405)Joint Fund of Ministry ofEducation,China(Grant No.6141A02011604)+2 种基金Major Scientific Research Project of Zhejiang Lab,China(Grant No.2019MB0AD01)National Program for Special Support of Top-Notch Young Professionals,China(Grant No.W02070390)Fundamental Research Funds for the Central Universities,China(Grant Nos.2016XZZX004-01 and 2018XZZX001-08).
文摘Sensing sensitivity is the key performance of optical tweezers.By adjusting the frequency and magnitude of an applied Coulomb force as an input of optical tweezers,we directly measured the sensitivity and signal-to-noise ratio(SNR)of a system and indirectly calculated the actual noise magnitude.Combined with an output filter,the relationship between the SNR and bandwidths was studied.We established the simulation model of a system using Simulink and simulated the relationship between the SNR and magnitude of the input forces and filter bandwidths.In addition,we built an experimental system to determine the relationship between the SNR and the magnitude of the input forces and filter bandwidths.The actual minimum detectable force was measured as 1.8275×10^(-17)N at a 1Hz bandwidth.The experimental results were correlated with the simulation and theoretical results,confirming the effectiveness of the proposed method and demonstrating the high sensitivity of vacuum optical tweezers as mechanical sensors.We proposed a novel method of calibration and measurement of system sensing parameters by applying an actual force that was more direct and precise than the theoretical calculation method that requires accurate fitting parameters,such as the particle radius and density.This method can be employed to analyze the system noise and phase characteristics to confirm and improve the real performance of the system.
