A discrimination measurement method and demodulation technique for fiber Bragg grating (FBG) sensors were presented using digital filtering technique. The system can control a tunable fiber Fabry-Perot filter with saw...A discrimination measurement method and demodulation technique for fiber Bragg grating (FBG) sensors were presented using digital filtering technique. The system can control a tunable fiber Fabry-Perot filter with sawtooth wave voltage generated by digital clock to interrogate FBG sensors. Using the analogue digital converter (ADC), the reflected FBG signals were sampled with synchronous digital clock. With the aid of digital matched filtering technique, the sampled FBG signals were processed to obtain the maximum signal-to-noise ratio (SNR) and the Bragg wavelength shift from the FBG signals was recovered. The results demonstrate that this system has a scanning range of 1 520 nm-1 575 nm,and the wavelength detection accuracy is less than 2 pm with 1.5 Hz scanning frequency.展开更多
Differential evolution algorithm is used to solve the inverse problem of strain distribution in fiber Bragg grating (FBG). Linear and nonlinear strain profiles are reconstructed based on the reflection spectra. An app...Differential evolution algorithm is used to solve the inverse problem of strain distribution in fiber Bragg grating (FBG). Linear and nonlinear strain profiles are reconstructed based on the reflection spectra. An approximate solution could be obtained within only 50 rounds of evolutions. Numerical examples show good agreements between target strain profiles and reconstructed ones. Online performance analysis illuminates the efficiency and practicality of differential evolution algorithm in solving the inverse problem of FBG.展开更多
基金Doctoral Foundation of Ministry of Education of China (No. 20040056008)
文摘A discrimination measurement method and demodulation technique for fiber Bragg grating (FBG) sensors were presented using digital filtering technique. The system can control a tunable fiber Fabry-Perot filter with sawtooth wave voltage generated by digital clock to interrogate FBG sensors. Using the analogue digital converter (ADC), the reflected FBG signals were sampled with synchronous digital clock. With the aid of digital matched filtering technique, the sampled FBG signals were processed to obtain the maximum signal-to-noise ratio (SNR) and the Bragg wavelength shift from the FBG signals was recovered. The results demonstrate that this system has a scanning range of 1 520 nm-1 575 nm,and the wavelength detection accuracy is less than 2 pm with 1.5 Hz scanning frequency.
基金Major Program of National Natural Science Foundation of China (No. 60537050)
文摘Differential evolution algorithm is used to solve the inverse problem of strain distribution in fiber Bragg grating (FBG). Linear and nonlinear strain profiles are reconstructed based on the reflection spectra. An approximate solution could be obtained within only 50 rounds of evolutions. Numerical examples show good agreements between target strain profiles and reconstructed ones. Online performance analysis illuminates the efficiency and practicality of differential evolution algorithm in solving the inverse problem of FBG.
