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针对光纤陀螺内部光纤在装配后光路闭合,无有效手段进行光纤缺陷检查,对光纤陀螺长期稳定可靠工作带来潜在危险的问题,提出利用红外视觉检测技术检查光纤缺陷,分析光纤缺陷图像特征,采用最大熵法进行图像分割,提出了结合直方图特征、缺陷区域形状特征、缺陷边界形状特征提取方法,采用改进的神经网络分类方法,用两层网络进行缺陷分类,识别判断不同类别的光纤缺陷。针对光纤缺陷图像的处理结果表明,该方法能够有效地检测光纤缺陷,对不可接受的缺陷能够100%地正确判断。 相似文献
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A sapphire fibre thermal probe with Cr3+ ion-doped end is developed by
using the laser heated pedestal growth method. The fluorescence thermal
probe offers advantages of compact structure, high performance and ability
to withstand high temperature in a detection range from room temperature to
450℃. Based on the fast Fourier transform (FFT), the fluorescence
lifetime is obtained from the tangent function of phase angle of the
non-zeroth terms in the FFT result. This method has advantages such as quick
calculation, high accuracy and immunity to the background noise. This FFT
method is compared with other traditional fitting methods, indicating that
the standard deviation of the FFT method is about half of that of the Prony
method and about 1/6 of that of the log-fit method. And the FFT method is immune
to the background noise involved in a signal. So,
the FFT method is an excellent way of processing signals. In addition,
a phase-lock amplifier can effectively suppress the noise. 相似文献
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