基于激光干涉的测量技术目前已在观测测量中被广泛应用, 测量设备也向着便携化、智能化和集成化的方向发展。目前的激光干涉测量设备大多是利用迈克尔逊干涉仪的原理, 然而, 该方法通常是将干涉信息在空间域上进行处理, 对实验平台搭建和测量环境的要求也较为苛刻, 在工业生产环境中运用时易受工业设备位移时产生的高频震动影响。因此, 提出一种基于激光双外差干涉的位移量精密测量系统, 利用两组激光外差信号来构成两组干涉仪, 探测器接收到回波拍频信号后进行时间域的平均与频域解调, 提高测量系统的鲁棒性, 使得测量系统的准确度达到0.01 mm。

The range finder and position shift observation based on laser interfering has been widely applied with the tendency of portability, intellection and integration. However, the present laser interfering devices for distance measurements are mostly based on Michelson interferometer. The interfering information is processed in the spatial domain. Sometimes the signal is probably influenced by the turbulence and the vibration introduced by large industrial equipment. Therefore, a kind of new measurement based on laser heterodyne interfering was proposed,which could transfer the signal process to the time domain in this article. In this system frequency-modulated laser beam was split into two interferometers. The detector received the beat signal and averaged the signal at the time domain and the computer demodulated the signal in the frequency domain. The testing results appeared as good robustness,and the testing error could be controlled within 0.01 mm.