一种光学三维测量中的相位计算及补偿方法

在基于格雷码和相移技术进行三维测量的过程中,相移光栅的非正弦性对测量精度有较大的影响。一般必须对获得的相位值进行修正以改进测量精度,常用的方法之一是物体相位传递函数,但其周期性假设使得修正结果仍然存在一定的误差。提出通过研究平面物体相位分布规律与标定相结合的方法。正确获得投影光栅在参考面的相位分布函数,降低光栅非正弦性的不利影响,消除物体相位传递函数周期性假设带来的误差,保证测量的精度和系统的健壮性。

STUDY ON PHASE CALCULATION AND COMPENSATING METHOD IN 3D OPTICAL SENSING

In 3D sensing based on gray-code and phase shifting, non-sinusoidal phase-shifting gratings influence the precision markedly. Traditionally the obtained phase value is corrected by applying the object phase transfer function (OPTF) to improve the measurement precision. But the corrected result still has definite errors because of the periodicity assumption of OPTF. It is suggested to get the accurate phase distributing function of the conference plane by studying the phase distributing rule of plane objects combined with system calibration, then reduce the influences of non-sinusoidal gratings, eliminate the error carried from the periodiclty assumption of OPTF, assure the measurement precision and the stability of measurement system.