激光与光电子学进展, 2020, 57 (2): 021503, 网络出版: 2020-01-03
基于改进单调法的阴影区相位噪声校正方法 下载: 855次
Correction Method of Shadow-Area Phase Noise Based on Improved Monotone Method
摘要
针对双目视觉系统中单调法校正阴影区相位噪声时存在校正不足的问题,提出了一种改进型相位校正方法。利用四步相移与多频外差求解工件表面的绝对相位信息,通过单调不减性对相位噪声进行校正。分析多组实验对象校正不足时相位噪声特点,根据相位频率矩阵计算固定区间内非零相位出现的频率来校正离散相位噪声,利用相邻间断点实际相位与预测相位的差值对连续相位噪声进行校正。计算间断点间的斜率与两侧非零相位的拟合斜率并进行判断,利用线性法补齐因随机噪声而被置零的部分相位,保证了工件信息的完整性。实验结果表明:所提方法可以有效校正阴影区的相位噪声,可适用于不同的实验对象,圆柱体木质工件的平均测量误差为0.0859 mm,精度可满足目标抓取的位姿估计要求。
Abstract
Herein, an improved phase correction method is proposed to address insufficient correction when a monotone method is applied to phase noise in the shadow area of binocular vision systems. The absolute phase information on the workpiece surface is solved using a four-step phase shift and multi-frequency heterodyne, and the phase noise is corrected using a monotone nonreduction method. We then analyze the characteristics of phase noise with insufficient correction of multiple sets of different experimental objects. Discrete phase noise is corrected based on the frequency at which non-zero phase occurs over a fixed interval calculated by the phase frequency matrix, and the continuous phase is corrected using the difference between the actual and predicted phases of the adjacent discontinuous points. The integrity of workpiece information is ensured by calculating and judging the slope between the discontinuous points and the fitting slope of the non-zero phase on both sides, and using the linear method to compensate the partial phase that is set to zero because of the random noise. Experiments are also given to demonstrate that the proposed method effectively corrects phase noise in the shadow area and can be applied to different experimental objects. The cylindrical wooden workpiece has an average measurement error of 0.0859 mm, which meets the accuracy requirements of pose estimation for target grabbing.
陶四杰, 白瑞林, 王昌龙. 基于改进单调法的阴影区相位噪声校正方法[J]. 激光与光电子学进展, 2020, 57(2): 021503. Tao Sijie, Bai Ruilin, Wang Changlong. Correction Method of Shadow-Area Phase Noise Based on Improved Monotone Method[J]. Laser & Optoelectronics Progress, 2020, 57(2): 021503.