深孔内表面缺陷特征内窥测量方法研究

Research on Endoscopic Measurement Method for Surface Defect Characteristics in Deep Holes

摘要: 在大深径比小孔径深孔、盲孔内表面几何参数测量领域，由于工作环境复杂，孔内表面缺陷的高质量检测面临较大挑战。针对这一难题，提出了一种基于光路分析的缺陷特征内窥成像方法。首先，通过分析单根光线的路径变化，构建缺陷高度与角度变化对出射光线偏移量影响的缺陷表征模型。其次，通过仿真实验对模型验证，证明了模型的准确性，并通过对不同高度缺陷和角度缺陷的多截面点云数据进行拼接，实现深孔内表面不同缺陷轴向三维重构，表征不同缺陷导致出射光线的变化结果。最后基于高精度实验平台模拟深孔内表存在缺陷，验证高度变化量平均误差为0.00438 mm，角度变化量平均误差为0.01556 mm，证明深孔内表面缺陷特征内窥测量方法准确性，可根据出射光线结果反演得到深孔内壁缺陷参数。

Abstract: In the field of measuring geometric parameters of the inner surface of deep and blind holes with large depth to diameter ratios and small apertures, high-quality detection of surface defects inside the holes faces significant challenges due to the complex working environment. A defective feature endoscopic imaging method based on optical path analysis is proposed to address this challenge. Firstly, by analyzing the path changes of a single light ray, a defect characterization model is constructed to investigate the impact of defect height and angle changes on the offset of the emitted light ray. Secondly, the accuracy of the model was verified through simulation experiments, and the multi section point cloud data of defects at different heights and angles were concatenated to achieve three-dimensional reconstruction of the axial direction of different defects on the inner surface of deep holes, characterizing the changes in the emitted light caused by different defects. Finally, based on a high-precision experimental platform, the presence of defects on the deep hole inner surface was simulated, and the average error of height change was verified to be 0.00438mm, and the average error of angle change was 0.01556mm. This proves the accuracy of the endoscopic measurement method for the characteristics of deep hole inner surface defects, which can invert the parameters of deep hole inner wall defects based on the emitted light results.