激光光栅干涉技术的微位移测量研究

为提升精密测量的精度与量程,提出了激光光栅干涉技术的微位移测量方法.通过集成双光栅微位移测量方法以2 组近似正交相位差的光栅交替选择并累积高灵敏度测量区域,扩大测量量程,且在测量过程中避免激光光束存在抖动问题,通过频率调解法实行外差干涉信号处理,转变待测物理量的信息为调相或调频信号,实现测量的高分辨率.检测结果表明,该...

Study on micro-displacement measurement of laser grating interferometry

In order to improve the precision and range of precision measurement,the micro displacement measurement method of laser grating interference technology is studied.Through the integrated double grating micro-displacement measurement method,two groups of grating with approximately orthogonal phase difference are alternately selected and the high sensitivity measurement area is accumulated,the measurement range is expanded,and the problem of laser beam jitter is avoided in measurement process.The heterodyne interference signal processing is carried out through frequency adjustment method,and the information of physical measurement to be measured is transformed into phase modulation or frequency modulation signal,so as to realize high resolution of measurement.The test results show that the method can measure the total displacement of movable parts,and the minimum displacement is 0.19 nm,which can realize micro-displacement measurement with a large range and high resolution.At the same time,the relative error of the method is less than 0.025°,the measurement accuracy is high,and the measurement result can be reliable.In addition,the laser incidence angle and groove depth have little influence on the measurement accuracy of the method,and have stable measurement performance and practical application value.