为了能够在有振动的环境中精确提取待测物体的相位,提出了一种 基于双时域傅里叶变换的相位提取算法。把一段具有2个干涉周期的时域光强信号分成多段1个周期的子段,进行2次傅里叶变换分离相移器引入的 相移频率和其他干扰频率。模拟和实验结果表明：该算法在不提高系统复杂性和大幅度减少数据获取量的 前提下,显著提高了系统抗干扰能力,与在理想条件下的传统四步相移算法相比,其测量均方根误差可以达到0.062 rad; 所提出方法从采集到待测物体相位的提取完全无须人工干预,有利于实现自动化。

In order to accurately extract the phase of the measured object in a vibrating environment, a phase extraction algorithm based on double time domain Fourier transform is proposed. A time domain light intensity signal with two interference periods is divided into several sub-segments with one period. The phase shift frequency introduced by phase shifter and other interference frequencies are separated by carrying out Fourier transform twice. Simulation and experimental results show that the algorithm significantly improves the system’s ability to resist interference under the premise of not improving the system complexity and greatly reducing the data acquisition amount. Compared with the traditional four step phase shift algorithm under the ideal condition, the root mean square error of the measurement can reach 0.062 rad. The proposed method is without manual intervention from acquisition to phase extraction of the measured object, which is conducive to the realization of automation.