非整数倍双频光栅投影的相位测量轮廓术  

Profilometry for phase measurement with non-integral twin-frequency grating

作　　者：陈永权[1] 曹益平[1] 常山[1] 

机构地区：[1]四川大学光电系,四川成都610064

出　　处：《光电工程》2006年第1期116-119,共4页Opto-Electronic Engineering

基　　金：四川省科技攻关项目资助(02GG010-010)。

摘　　要：采用整数倍双频光栅投影的借助低频相位导向的双相位图成整数比例相位展开方法不可避免误差积累传递,由此提出了一种采用非整数倍双频光栅投影的新光学三维传感方法。非整数倍双频光栅条纹投影到物体上,两相位同时分别以特定相位间隔增长,CCD依次获取16帧变形条纹图,通过这16帧条纹图的强度,可有效地分离出两组受物体调制的对应频率变形条纹的截断相位。利用两组截断相位关系,进行绝对相位展开,避免相位展开中误差的传递,较好地重建了被测物体的轮廓。计算机模拟试验结果证实,该方法与采用整数倍双频光栅投影相比,测量高度为105mm的同一不规则物体时,标准偏差由0.821mm降低到0.760mm。Due to integral proportional two-phase-unwrapping method which adopts integral twin-frequency grating and low-frequency guide will result in error transfer, a novel optical 3-D sensing method using non-integral twin-frequency grating is proposed. The non-integral twin-frequency grating patterns are projected onto the object to be measured, and the two phases increases at a regular intervals simultaneity. Sixteen frames of deformed patterns can be taken by the CCD system. Based on pattern intensity, two groups of corresponding discrete phases modulated by the object can be separated efficiently and calculated accurately. From the relationship between two groups of discrete phases, the absolute phase-unwrapping method is developed successfully, by which error transfer can be eliminated and the profile of the object to be measured can be reconstructed accurately. Computer simulation shows that standard deviation drops from 0.821mm to 0.760mm comparing with integral twin-frequency grating in measuring an identical irregular object 105mm high.

关 键 词：双频光栅 相位测量轮廓术 相移 绝对相位展开 

分 类 号：TN247[电子电信—物理电子学]