中文摘要：

针对大型工件的几何尺寸和形状的测量问题，研究了一种激光跟踪测距方法。由双模热稳频He-Ne激光器产生的双频信号，通过拍波后，以拍波波长作为“光尺”，拍波零点对位确定拍波节点数，以同轴光路组合形成的双频激光干涉测量尾数。跟踪定位采用自适应跟踪，控制跟踪反射镜沿水平轴和垂直轴的转动，定位信号由CCD采集入射光与出射光之间的偏移量。同时，驱动系统带动两个光栅编码盘输出跟踪反射镜转动的水平角度值和垂直角度值，实现空间尺寸测量。研究的激光跟踪测量系统具有抗干扰能力强，跟踪速度快，测量精度高的特点。

英文摘要：

A distance measuring method of the laser tracking system was presented for measuring the geometry and shape of large workpiece. After the two-frequency light signal produced by bimodal hotsteady frequency He-Ne laser is beaten, the beating-wave length is taken as ＂light size＂. The number of beating-wave point can be determined from a beating-wave zero position after beating the light wave, and the partial wave length can be also measured by the two-frequency laser interference using a coaxial light path. An adaptive tracking method is used for laser tracking and positioning, and controlling the moving of reflecting mirror along horizontal axis and vertical axis. For a locating signal, the angle offset between incident light and exit light is obtained by a CCD sampling unit. Then, the absolute distance measurement in large size machining can be realized by the driving system making two light-grating coders to control and track the reflecting mirror. The laser tracking system has very high measuring precision, fast tracking speed and anti-interference capability.