在线喷印视觉检测系统的研究

Research on On line Visual Detection System for Jet Printing

针对瓦楞纸箱上型号标志传统粘贴工艺成本高、效率低等问题,对在线喷印视觉检测系统进行了研究。这一系统采用带滚动导向的喷头自适应机构,兼容不同尺寸的瓦楞纸箱,由与喷头保持相对静止的工业相机进行喷印字符质量监控,实现型号标志的在线喷印及喷印字符质量的视觉检测。对图像采集与喷印区域定位、喷印字符分割与特征提取、喷印字符配准、喷印字符缺陷与非喷印字符缺陷提取等关键技术进行了分析。测试数据表明,对于不同字体、不同字号、不同粗细且存在整体随机畸变叠加局部随机畸变的喷印字符型号标志,在线喷印视觉检测系统的检测准确率达到100%,缺陷检测精度达到0.06 mm^2,检测时间短于0.2 s,可以实现对喷印字符缺陷进行实时快速准确检测。这一系统拥有良好的自适应性、鲁棒性与自检性,在自动化喷印行业中具有较高的应用价值。

In view of the challenges of high cost and low efficiency of the traditional pasting process of the model logo on the corrugated box,the online visual detection system for jet printing was studied.This system adopts a self adapting mechanism with a roll guided injection head compatible with different sizes of corrugated boxes,and uses an industrial camera that remains relatively stationary with the injection head to monitor the quality of the jet printed characters to achieve online jet printing of the model logo and visual detection of the quality of the jet printed characters.The key technologies such as image acquisition and printing area positioning,printing character partition and feature extraction,printing character registration,extraction of the defects in jet printed characters and non jet printed characters were analyzed.The test data shows that for different fonts,different font sizes,different thicknesses and for jet printed characters and model logos with overall random aberration and partial random aberration,the detection accuracy of the online visual inspection system for jet printing reaches 100%.The accuracy for defect detection reaches 0.06 mm^2,and the detection time is shorter than 0.2 s,which can realize real time rapid and accurate detection of the defects in jet printed character.This system has good adaptability,robustness and self checking capability,and has high application value in the automatic jet printing industry.