赵亮亮+张艳飞+朱雯彦+江会煜+裴蕾+肖志涛

摘要：表面编织角和花节距是三维编织复合材料预制件的两个重要表面参数。提出基于霍夫变换和基于自相关的平均编织角和平均花节距的测量方法。首先通过基于“球积分光源+偏振片+CCD相机”的图像采集方案获得三维编织物原始图像，用偏微分方程滤除织物图像噪声，然后用相位一致性进行特征提取，并用霍夫变换进行直线提取，计算平均编织角；通过自相关变换计算平均花节距。实现了碳纤维材质的三维编织复合材料预制件平均编织角和平均花节距的自动测量。

关键词：三维编织复合材料；自相关；偏微分方程；相位一致性；霍夫变换；编织角；花节距

中图分类号：TP391.41 文献标识码：A 文章编号：1009-3044（2016）35-0292-04

Measurement of Surface Parameters of Three-dimensional Braided Composite Preform

ZHAO Liang-liang， ZHANG Yan-fei， ZHU Wen-yan， JIANG Hui-yu， PEI Lei， XIAO Zhi-tao

（School of Electronics and Information Engineering， Tianjin Polytechnic University， Tianjin 300387， China）

Abstract：Braided angle and pitch length are two important surface parameters of three-dimensional braided composite preform. In this paper， a method based on Hough transform and autocorrelation is proposed to measure braided angle and pitch length of carbon fiber. Firstly， three-dimensional braid original image is obtained based on the image acquisition scheme of "spherical integral source + circular polarizing filter+ CCD camera". Secondly， the noise of the image is filtered out with partial differential equation. Thirdly， the image edge is extracted using phase congruency. Finally， straight lines are gotten using Hough transform， then the average braided angle can be calculated and the pitch length can be gotten based on autocorrelation. The proposed method achieves automatic measurement of average braided angle and average pitch length of three-dimensional braided composite perform and its performance is demonstrated.

Key words： three-dimensional braided composite； auto-correlation； partial differential equation； phase congruency； Hough transform； braided angle； pitch length

1 背景

三維编织复合材料是先进的新型高性能复合材料，具有高比强度、高比模量等优异特点，且在可设计性、整体成型性及净截面制造等方面具有明显优势，已广泛地应用于航空、航天、交通运输、石油化工、武器装备、体育用品及医疗等诸多领域[1]。表面编织角和花节距是三维编织复合材料预制件的两个重要表面参数，从其中可反映预制件内部结构和性能[2]。表面编织角θ，是指三维编织物表面纤维束与织物轴向方向形成的夹角；花节距h，是指在一个机器编织周期中沿着编织方向产生的长度。编织角和花节距的示意图如图1所示，其中图1（a）为理想情况下编织角和花节距，图1（b）为实际情况下编织角和花节距。……