量块中心长度绝对测量中干涉条纹的自动判读

利用高分辨率的图像采集系统读取干涉条纹，是提高量块长度测量准确度的前提条件。该文介绍利用激光干涉与数字图像处理技术以及应用快速傅里叶变换分析干涉条件方法，分析并解决量块中心长度的自动测量。系统采用了２个频率稳定的激光器，提高了视场照度和相干强度。分别在２种波长下，自动测量量块中心干涉条纹小数部分。仪器由ＣＣＤ摄取干涉条纹，计算机计算量块中心条的位置。该方法不但提高仪器的自动化程度，而且能够提高测量

Automatic Interference Fringes Processing in the Absolute Measurement of Central Length of Gauge Block

Using high resolution image sampling system to recognize interference fringes is the premise of improving the measurement accuracy of gauge block length.Based on laser interference,digital image processing technology and the FFT method,this paper analyzes and solves the problems on automatic interference fringe processing in absolute measurement of central length of gauge block.The system makes use of two frequency stabilised lasers to increase the illuminance and coherence strength.The fractions of central fringe of gauge blocks were measured automatically at the two wavelengths,the interference fringes were photographed with a CCD camera and the central fringe's positions were calculated with a computer.The method has the instrument more automatized and provides higher accuracy in measurement as well.