基于光栅干涉原理的高精度微位移测量装置电压灵敏度高,微弱的抖动都会影响测量精度,这些抖动包括空气波动,地面震动,光源波动等,因而如何有效抑制外界抖动对微位移测量结果的影响显得至关重要。本文首先针对实验所用光源线偏振He-Ne激光器的功率波动性进行实验和分析,得出光源的功率波动范围大于7%,超出1%的波动限制;然后采用两路信号采集的补偿措施,后经比例运算降低光源波动对输出电压的影响,实现抗光源扰动的目的。通过对实验数据的分析得出经过补偿光路和比例运算以后输出电压受光源波动的影响得到了有效抑制,最终输出电压的波动幅度较初始状态降低了60%,位移测量误差从1.95×10-7 m降低到1.40×10-8 m。
Micro displacement measuring device with high precision based on the principle of grating interference has high voltage sensitivity, thus weak jitter can cause irreparable impact on measuring results. These jitters include the air jitter, the ground vibration, and the fluctuation of the light source, etc. It becomes crucial for how to restrain the influence of outside jitter on the measurements of micro displacement effectively. Firstly, a series of experiments and analyses was carried on for the power fluctuation of the linearly polarized He-Ne laser, which drew that the power fluctuation range of light was greater than 7% which exceeded the fluctuation limit of 1%. Then, using the compensation measures of two signal acquisition and scaling operation, anti light disturbance came true. The analysis of experimental data shows that the effect of light source fluctuation on output voltage can be suppressed effectively through the compensation of optical path and scaling operation. The final amplitude of fluctuation of the output voltage is reduced by 60% than the initial state, and the displacement measurement error reduced from 1.95×107m to 1.40× 10.8 m.