摘要
为了降低振动对移相干涉测量的影响,对振动信号进行频谱分析,分离出对低频振动有贡献的频谱信号,由此验证了PSI(phase-shifting interferometry)算法在 2倍移相频率处对振动更加敏感的事实.根据标准的PSI测量步骤,再结合牛顿广义二项式定理,推导出多频率振动影响因子γ,通过Matlab软件仿真了由标准PSI算法求出的相位误差以及多频率振动影响因子γ处理后的相位误差,并进行实验加以验证.实验结果显示,经γ影响因子处理后的波面RMS值和相位误差均低于PSI算法,RMS值减小22倍,相位误差减小20倍.
Abstract
In order to reduce the influence of vibration on phase-shifting interferometry,the spectrum analysis of the vibration signal was carried out to separate the spectrum signal that contributed to the low-frequency vibration,which verified the fact that the phase-shifting interferometry(PSI)algorithm was more sensitive to vibration at 2 times the phase-shifting frequency.According to the standard PSI measurement steps and Newton's generalized binomial theorem,the multi-frequency vibration influence factor γ was derived.The phase error calculated by the standard PSI algorithm and the phase error after the multi-frequency vibration influence factor γ processing were simulated by Matlab software,and the experiment was carried out to verify it.The results show that the RMS value and phase error of the wavefront processed by the γ influence factor are lower than those of the PSI algorithm.The RMS value can be reduced by 22 times and the phase error can be reduced by 20 times.
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