基于双目结构光的手机中框特征提取研究

Research on Feature Extraction of Mobile Phone Middle Frame Based on Binocular Structured Light

目前手机自动点胶作业中的路径提取普遍使用线结构光结合二维图像分析的方法,线结构光精度较高但速度较慢,二维图像分析方法需花费大量时间调试,普适性差。为提升手机中框点胶效率与精确度,设计一个基于双目结构光的手机中框特征提取系统。该系统使用四步相移法结合格雷码的编码方案,引入鲁棒的格雷码二值化方法,在提升精度的同时过滤背景。经极线矫正后解码,根据解码信息相位匹配后计算三维点云坐标。对点云模型预处理后使用结合粗提取与精提取的点云轮廓提取方法,使用RANSAC拟合轮廓线,沿法向量偏移后获得点胶路径。实验结果表明,在保证精度的情况下,该系统三维成像时间为线激光方法的26.1%,总处理时间为线结构光结合二维图像分析方法的56.5%,鲁棒性更好。点云轮廓提取方法提取速度快、提取效果稳定,为高效自动点胶打下了良好基础。

Path extraction in automatic dispensing operations on mobile phones commonly uses a combination of line structured light and two-dimensional image analysis methods.Line structured light has high accuracy but slow speed,and two-dimensional image analysis methods re-quire a lot of time to debug and have poor universality.To improve the efficiency and accuracy of dispensing glue on mobile phone frames,a feature extraction system for mobile phone frames based on binocular structured light is designed.The system uses a four step phase-shifting method to encode qualified Lei codes,and introduces a robust Gray code binarization method to improve accuracy while filtering the back-ground.After polar correction and decoding,the three-dimensional point cloud coordinates are calculated based on phase matching of the de-coding information.After preprocessing the point cloud model,a point cloud contour extraction method combining coarse and fine extraction is used.RANSAC is used to fit the contour lines,and the dispensing path is obtained by offsetting along the normal vector.The experimental re-sults show that,while ensuring accuracy,the three-dimensional imaging time of the system is 26.1%of that of the line laser method,and the total processing time is 56.5%of that of the line structured light combined with two-dimensional image analysis method,indicating better ro-bustness,which has a fast extraction speed and stable extraction effect,laying a good foundation for efficient automatic dispensing.