相位测量轮廓术中一种有效补偿相移误差的新算法

A new method for compensating phase-shifting error in phase measuring profilometry

提出了相位测量轮廓术中一种新的相移误差求取算法,利用了正弦投影条纹中相邻像素点间相位差的相等性特点,以相邻3个相位点为研究对象,结合相位补偿测量原理,将每个相位点的相位由含相移误差的方程表示.依据相邻两点相位差相等的特点,构造出一个求取相移误差的方程.将这种方法求出的相移误差代入相移公式中进行误差补偿,仿真结果验证了新算法对相移误差的抑制效果.最后利用新算法对实物进行了三维重构测量,从最终得到的结果明显可以看出,使用新算法进行误差补偿后,对实物的重构效果较清晰,误差提取算法有效地提高了三维测量的精度.

A new phase-shifting error compensating algorithm for phase-measuring profilometry is proposed. In this error detecting algorithm,it is supposed that sinusoidal fringe is projected to the plate,thus the phase differences between adjacent pixels are equal. Three adjacent phase points are taken as the research object. Combining the principle of phase compensation measurement,each phase of the point is presented as an equation containing the phase-shifting error. According to the characteristics that the phase differences between adjacent pixels are equal,an equation to calculate the phase-shifting error is constructed. Then the phase shifting error is taken into account in the original algorithm for error compensation. Simulation results show the inhibitory effect of the error compensation by using the novel algorithm. The proposed algorithm is also used for three-dimensional reconstruction. The final result shows that the new compensation algorithm is better than the original one obviously. This error compensating algorithm can effectively improve the accuracy of three-dimensional measurement.