胎面花纹边界特征提取及重构方法研究*(9)

Research on Boundary Features Extraction and Reconstruction for Tire Tread Patterns

为解决轮胎硫化工序中制造成型花纹与设计花纹存在偏差的问题,提出一种从胎面扫描数据中提取花纹边界特征并进行加工特征重构的新方法。该方法依据花纹节距排布和挤压压延成型工艺确定空间分割方案,利用轮廓设计理论和主成分统计分析方法获取胎顶轮廓曲线,从而实现三维点云向二维灰度图像(带有深度值)的转化,根据花纹的增长规律并借鉴区域增长法的思想对花纹边界特征进行识别和提取。结合三次样条插值法将花纹边界离散化处理为一簇等间距坐标点的形式,最终根据最佳一致逼近的定义实现自适应相切连续圆弧直线的花纹曲线逼近。实验结果表明,该方法可在90 s左右的时间内完成各种半钢子午线轮胎花纹的重构,特征提取误差不大于0.15 mm,重构误差绝对值均值不超过0.25 mm,最大值不超过0.4 mm。该方法不仅能快速有效提取胎面花纹边界特征并重构,并且解决了传统逆向工程技术在花纹重构中失真性的问题,为花纹开发效率的提高和综合性能的改善提供了指导方向。

In order to solve the deviation problem between tread pattern and design pattern in the process of tire vulcanization, a new method is proposed to extract and reconstruct tread pattern feature from tire tread scan data. Firstly, A new space segmentation method is determined according to the pattern pitch arrangement and the extrusion and calendering process, secondly, obtained the Contour of the tire crest by contour design theory and principal component analysis method, and finally successfully transformed the dimensional point cloud to the two-dimensional gray image(with depth value). According to the growth rhythm of the pattern and the idea of regional growth law, the pattern border characteristics can be identified and extracted accurately. The cubic boundary spline interpolation method is used to discretize the pattern boundary into a series of equidistant coordinate points. And finally, the approximation of tread curve of Self-adaptive Tangent Continuous Circle and Line is realized according to the definition of optimal uniform approximation. The experimental results show that the method can be used to reconstruct the tire tread pattern of various semi-steel radial tire in about 90 s, the feature extraction error is less than 0.15 mm, the mean value of reconstruction error absolute value is less than 0.25 mm, the maximum value is less than 0.4 mm. This method can extract and reconstruct the tread pattern boundary feature effectively and deal the distortion problem in pattern reconstruction of traditional reverse engineering technology, as well as provides a direction for improvement of the efficiency of pattern development and the comprehensive performance of the tire.