针对多频外差解相法易产生相位跳跃性误差的问题,提出一种基于多级条纹级数修正的相位误差校正方法。根据叠加条纹的相位周期对叠加条纹级数进行第一级粗修正,可有效避免由伽马效应以及取整函数引起的相位跳跃性误差的累积和传递。优化取整函数,并利用误差绝对相位对初始条纹级数进行第二级精细修正。再根据修正后的条纹级数计算更为精确的目标绝对相位。实验测试结果表明,经本文方法校正后的三维重构模型表面平整光滑、细节清晰且无明显色斑和色块,对相位跳跃性误差有明显的改善作用,提高了结构光三维测量系统的鲁棒性。

Herein, a phase error correction method based on a multi-level fringe order correction was proposed to address the issue of the easy generation of the phase-jump error in the multi-frequency heterodyne phase unwrapping method. First, the initial rough correction was performed on the synthetic fringe orders according to the phase period of the synthetic fringe, which can effectively avoid further accumulation and transmission of the phase-jump error caused by the Gamma effect and flooring function. Thereafter, the secondary fine correction was performed on the initial fringe orders by optimizing the flooring function and using the absolute phase of the error. Finally, a more accurate target absolute phase was calculated based on the corrected fringe orders. Experimental results showed that the three-dimensional reconstruction model corrected by the proposed method exhibited a smooth surface, clear details without obvious spots or color patches, which can significantly suppress the phase-jump error and enhance the robustness of the structural light three-dimensional measurement system.