光反馈自混合干涉位移实时跟踪测量算法改进

Improvement of real-time tracking measurement algorithm for optical feedback self-mixing interference displacement

现有的相位测量算法进行光反馈自混合干涉位移实时跟踪测量时,未考虑原始光反馈自混合干涉信号中的噪声干扰,导致测量精度差。因此,对光反馈自混合干涉位移实时跟踪测量算法进行改进,采用自适应滤波系统去除光反馈自混合干涉信号中的噪声,通过去噪后的自混合信号实施变换处理获取解析信号,提取解析信号的包裹相位突变点,根据相位突变点与正负单位脉冲的乘积定位相位突变点的正确方向,得到自混合干涉条纹;去除自混合干涉条纹中的小数条纹获取全部整数条纹点,对条纹点进行赋值、差值和平滑处理,获取外部目标重构位移轨迹,即光反馈自混合干涉位移。实验结果表明,所提算法具有较高的光反馈自混合干涉位移实时跟踪测量精度。

The noise interference in original optical feedback self-mixing interference signals is not considered when the current phase measurement algorithm is used for real-time tracking measurement of optical feedback self-mixing interference dis placement,resulting in poor measurement accuracy.Therefore,improvement of the real-time tracking measurement algorithm for optical feedback selfmixing interference displacement is conducted.The adaptive filtering system is adopted to remove the nois es in optical feedback self-mixing interference signals.The transform processing of denoised self-mixing signals is conducted to obtain the analytic signals.The mutation points for the wrapped phase of analytic signals are extracted.The correct direction of phase mutation points is located according to the product of the phase mutation point and the positive or negative unit pulse,so as to obtain self-mixing interference stripes.The decimal stripes in self-mixing interference stripes are removed to obtain all the integer stripe points.The stripe points are assigned,interpolated and smoothed to obtain the displacement track of external target reconfiguration,that is,optical feedback self-mixing interference displacement.The experimental results show that the proposed algorithm has high accuracy in real-time tracking measurement of optical feedback selfmixing interference displacement.