Abstract Random fluctuations of the nonlinearity curves of Fabry–Perot (F–P) tunable filters cause instabilities in fiber Bragg grating (FBG) interrogation systems. FBG sensors are widely used in structural health monitoring (SHM), and suppressing random fluctuations can provide engineers with more precise information on the conditions of structures. While F–P etalon and acetylene (C2H2) are most commonly used to calibrate the wavelength of the F-P filter, in medium–high sweeping situations, they suffer from drastic fluctuations in the interrogation results. In addition, these two methods require more interrogation components and render the interrogation system more complex and expensive. This study investigates the fluctuation of interrogation errors caused by sampling frequency. A novel self-adaptive sampling approach based on particle swarm optimization (PSO) is proposed to automatically search the optimal sampling frequency with the smallest fluctuation. The experimental results show that the proposed approach successfully detected the optimal sampling frequency. The drastic fluctuations of micro strains caused by high sampling frequency are avoided completely, and the stability of interrogation system is guaranteed. The proposed approach is thus helpful for suppressing sweeping fluctuations by appropriately choosing the optimal sampling frequency.

中文翻译：

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使用基于PSO的自适应采样抑制光纤布拉格光栅询问中法布里-珀罗滤波器的扫描波动

摘要 法布里-珀罗 (F-P) 可调滤波器非线性曲线的随机波动会导致光纤布拉格光栅 (FBG) 询问系统的不稳定性。FBG传感器广泛用于结构健康监测（SHM），抑制随机波动可以为工程师提供更精确的结构状况信息。虽然 F-P 标准具和乙炔 (C2H2) 最常用于校准 FP 滤光片的波长，但在中高扫描情况下，它们会遭受询问结果的剧烈波动。此外，这两种方法需要更多的询问部件，使得询问系统更加复杂和昂贵。本研究调查由采样频率引起的询问误差的波动。提出了一种基于粒子群优化（PSO）的新型自适应采样方法，以自动搜索波动最小的最佳采样频率。实验结果表明，所提出的方法成功地检测到了最佳采样频率。完全避免了高采样频率引起的微应变的剧烈波动，保证了询问系统的稳定性。The proposed approach is thus helpful for suppressing sweeping fluctuations by appropriately choosing the optimal sampling frequency. 完全避免了高采样频率引起的微应变的剧烈波动，保证了询问系统的稳定性。The proposed approach is thus helpful for suppressing sweeping fluctuations by appropriately choosing the optimal sampling frequency. 完全避免了高采样频率引起的微应变的剧烈波动，保证了询问系统的稳定性。The proposed approach is thus helpful for suppressing sweeping fluctuations by appropriately choosing the optimal sampling frequency.