针对镜面物体三维测量系统中两显示屏无法精确平行正对的问题, 提出了一种在镜面物体三维测量系统中通过软件产生变形条纹等效两显示屏精确平行正对的方法。该方法首先采用机器视觉技术标定两显示屏的外参。然后基于所标定的外参, 利用软件编程产生等效两显示屏平行正对的变形条纹, 变形条纹通过半透半反镜后所成的像在相机坐标系内呈现前后精确平行正对的关系。最后, 利用对应两个显示屏上的变形条纹计算相应位置相位的差值, 并通过均方根误差定量评定所提出的方法。实验结果表明, 所提出的方法能将水平方向的均方根误差缩减为原来的24.21%, 竖直方向的均方根误差缩减为原来的8.15%, 从而提高三维测量系统的精度。

Aiming at the inaccurate parallel-alignment of two display screens in three-dimensional (3D) measuring system of specular surfaces, this paper proposes a method for generating deformed fringes by software to be equivalent to the exact parallel-alignment of two display screens. The machine vision technology was employed to calibrate external parameters of the two displays, based on which the deformed fringes equivalent to parallel-alignment two display screens were produced by software programming. A camera captured the parallel-alignment fringe pattern through the beam splitter in the camera coordinate system. The difference of the corresponding phase was calculated with the deformed fringe patterns on the two display screens. The proposed method was quantitatively evaluated by the errors of root-mean-square. Experimental results show that the proposed method can reduce the errors of root-mean-square to 24.21% in horizontal direction and 8.15% in vertical direction of the original ones respectively, thus improving the accuracy of 3D measurement system.