Research on Quadric Surface Fitting Algorithm Based on CT Data
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摘要: 二次曲面工件在工业中比较常见,为测量物体内部的二次曲面,本文采用工业计算机断层成像(CT)技术获取物体的断层图像序列,利用U-net图像分割网络获得断层图像上的目标区域,对分割结果的边缘进行检测和曲线拟合并堆叠成三维点集,通过曲面拟合获取物体曲面的三维空间坐标信息。研究结果表明,本文的方法能够有效地实现边界提取和界面参数的拟合工作,拟合误差在1% 以内,相比传统方法有较大改进。Abstract: Quadric surface is a common type of workpiece shape in industry. It can be imaged by computed tomography (CT). A sample object was scanned and its slices were reconstructed to measure its internal quadric surface. We used the U-net image segmentation network to obtain the interested region and then detected the edge in the segmentation results and obtained curve fitting results. The curves were stacked into a three-dimensional point set. The three-dimensional spatial coordinate information for the internal quadric surface was computed through surface fitting. The results demonstrate that the proposed method can effectively extract the internal quadric surface parameters, and the fitting error can be controlled within 1%, which is superior to that achieved with a traditional algorithm.
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Key words:
- ICT /
- deep learning /
- quadric surface /
- curving fitting
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表 1 拟合结果
Table 1. Fitting results
数据精简方式 曲面高度Δh/mm 曲面曲率δ/% 模体值 拟合值 相对误差/% 模体值 拟合值 相对误差/% 进行异常数据剔除 14.6 14.67 0.40 0.0973 0.0978 0.40 不进行不变层去除 14.6 15.04 3.01 0.0973 0.1002 3.01 不进行稳定层去除 14.6 13.39 8.29 0.0973 0.0892 8.29 -
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