正交光栅相移轮廓术的相位误差分析及其校正  

Phase Error Analysis and Correction for Phase Shifting Profilometry Using Crossed Grating

作　　者：李付谦 陈文静[1] Li Fuqian;Chen Wenjing(Department of Optic-Electronic,College of Electronies and Information Engineering,Sichuan University,Chengdu,Sichuan 610065,China)

机构地区：[1]四川大学电子信息学院光电系,四川成都610065

出　　处：《光学学报》2021年第14期87-98,共12页Acta Optica Sinica

基　　金：国家自然科学基金(62075143);国家重大仪器设备开发专项(2013YQ490879)。

摘　　要：正交光栅投影的相移轮廓术(PSP),可通过某一特定方向的相移(常利用相移调节因子来控制相移方向),获取两个相互正交的相位。但该方法对系统的非线性响应敏感,且目前尚未被深入讨论。为此,分析了系统的非线性响应对正交光栅相移轮廓术测量的影响,推导了带有非线性误差的相位表达式,并分析了两个方向相位相互串扰的原因。在此基础上,分别研究了抑制非线性误差的主动校正法和被动校正法,提出了可消除2阶非线性误差的双5步相移法,并利用基于统计分析的伽马校正法确定系统伽马值,主动改变正交条纹编码来抑制非线性误差。同时,完成了两种方法的对比,计算机仿真和实验结果表明,主动伽马校正法更实用。Phase shifting profilometry(PSP) based on crossed grating projection can acquire two orthogonal phases by a phase shifting algorithm in a specific direction(the phase shifting direction is usually controlled by a phase shifting adjustment parameter). However, this technique is sensitive to the nonlinear response of the projector-camera system and has not been studied in depth yet. In this paper, we examine the effect of the nonlinear response of the system on PSP based on crossed gratings, derive phase expressions with nonlinear errors, and analyze the reason for the phase crosstalk in two directions. On this basis, we study the active and passive correction methods for the suppression of nonlinear errors. To be specific, a double five-step PSP method based on the derived mathematical expressions is proposed to passively suppress the second-order nonlinear errors. The Gamma correction method based on statistical analysis is also studied, by which the projected crossed gratings are pre-encoded to actively offset the effect of the nonlinear errors. The two methods are compared in terms of practicality. The simulation and experimental results show that the Gamma correction method is more practical to improve measurement accuracy.

关 键 词：测量 相移轮廓术 正交光栅投影 非线性分析 相位分析 相位误差校正 

分 类 号：O438[机械工程—光学工程]