We present an all-digital demodulation system of interferometric fiber optic sensor based on an improved arctangent-differential-self-multiplying(arctan-DSM)algorithm.The total harmonic distortion(THD)and the light in...We present an all-digital demodulation system of interferometric fiber optic sensor based on an improved arctangent-differential-self-multiplying(arctan-DSM)algorithm.The total harmonic distortion(THD)and the light intensity disturbance(LID)are also suppressed,the same as those in the traditional arctan-DSM algorithm.Moreover,the lowest sampling frequency is also reduced by introducing anti-aliasing filter,so the occupation of the system memory is reduced.The simulations show that the improved algorithm can correctly demodulate cosine signal and chirp signal with lower sampling frequency.展开更多
For expanding the amplitude-frequency response range of the differential cross-phase multiply(DCM)algorithm in theφ-OTDR system,a temporal spline interpolation(TSI)method is proposed to pre-process Rayleigh backscatt...For expanding the amplitude-frequency response range of the differential cross-phase multiply(DCM)algorithm in theφ-OTDR system,a temporal spline interpolation(TSI)method is proposed to pre-process Rayleigh backscattering(RBS)signals.Through the TSI method,the discrete temporal signals characterizing RBS traces are subjected to interpolation,facilitating a reduction in differential approximation errors.This,in turn,establishes a heightened level of precision in phase demodulation,especially relevant across extensive sensing distances.By comparing the recovered time-domain waveforms and the corresponding power spectral densities without and with the TSI,the above improvement effect has been experimentally validated by utilizing the TSI.The results show that,with the TSI,the amplitude-frequency response range of the DCM algorithm is enlarged by 2.78 times,and the new relationship among f_(pulse),f,and D under the root mean square error(RMSE)tolerance less than 0.1 can be expressed as 1.9(D+1)f≤f_(pulse).This contribution underscores a substantial advancement in the capabilities of the DCM algorithm,holding promise for refined performance in optical fiber sensing applications.展开更多
针对声发射检测齿轮箱轴承故障问题,提出基于奇异值分解(Singular Value Decomposition,SVD)与Fast Kurtogram算法的故障诊断方法。通过奇异值分解提高信号信噪比;将Fast Kurtogram算法用于故障信号共振解调带通滤波器参数确定,结合能...针对声发射检测齿轮箱轴承故障问题,提出基于奇异值分解(Singular Value Decomposition,SVD)与Fast Kurtogram算法的故障诊断方法。通过奇异值分解提高信号信噪比;将Fast Kurtogram算法用于故障信号共振解调带通滤波器参数确定,结合能量算子解调包络谱,成功提取齿轮箱轴承内外圈故障特征,有效改善传统共振解调中人工选择滤波器参数的不确定性。通过仿真与实验数据验证所提方法的有效性。展开更多
文摘We present an all-digital demodulation system of interferometric fiber optic sensor based on an improved arctangent-differential-self-multiplying(arctan-DSM)algorithm.The total harmonic distortion(THD)and the light intensity disturbance(LID)are also suppressed,the same as those in the traditional arctan-DSM algorithm.Moreover,the lowest sampling frequency is also reduced by introducing anti-aliasing filter,so the occupation of the system memory is reduced.The simulations show that the improved algorithm can correctly demodulate cosine signal and chirp signal with lower sampling frequency.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.62075153,62075151,and 62205237)in part by the Shanxi Provincial Key Research and Development Project(Grant No.202102150101004)+2 种基金in part by the Shanxi Provincial Central Guiding Local Science and Technology Development Fund Project(Grant No.YDZJSX20231A019)in part by National Key Research and Development Program of China(Grant No.2023YFF0715700)in part by Natural Science Foundation for Young Scientists of Shanxi Province(Grant No.20210302124396).
文摘For expanding the amplitude-frequency response range of the differential cross-phase multiply(DCM)algorithm in theφ-OTDR system,a temporal spline interpolation(TSI)method is proposed to pre-process Rayleigh backscattering(RBS)signals.Through the TSI method,the discrete temporal signals characterizing RBS traces are subjected to interpolation,facilitating a reduction in differential approximation errors.This,in turn,establishes a heightened level of precision in phase demodulation,especially relevant across extensive sensing distances.By comparing the recovered time-domain waveforms and the corresponding power spectral densities without and with the TSI,the above improvement effect has been experimentally validated by utilizing the TSI.The results show that,with the TSI,the amplitude-frequency response range of the DCM algorithm is enlarged by 2.78 times,and the new relationship among f_(pulse),f,and D under the root mean square error(RMSE)tolerance less than 0.1 can be expressed as 1.9(D+1)f≤f_(pulse).This contribution underscores a substantial advancement in the capabilities of the DCM algorithm,holding promise for refined performance in optical fiber sensing applications.
文摘针对声发射检测齿轮箱轴承故障问题,提出基于奇异值分解(Singular Value Decomposition,SVD)与Fast Kurtogram算法的故障诊断方法。通过奇异值分解提高信号信噪比;将Fast Kurtogram算法用于故障信号共振解调带通滤波器参数确定,结合能量算子解调包络谱,成功提取齿轮箱轴承内外圈故障特征,有效改善传统共振解调中人工选择滤波器参数的不确定性。通过仿真与实验数据验证所提方法的有效性。
