基于机器视觉的LED质检装备精度标定方法研究

发布时间：2018-07-05 01:48

本文选题：LED + 视觉当量　；参考：《华中科技大学》2015年硕士论文

【摘要】：在LED芯片生产工艺流程中,LED芯片在进行封装之前需要进行光电参数测试,然后进行分类分选,后续芯片封装对分选后的芯片的排列精度要求很高。为了保证芯片的排列精度,在LED检测分选一体机出厂前必须对其进行精度标定。然而,LED一体机精度标定比较复杂,而且当前的标定效率非常低。本文通过提出LED一体机视觉标定方法,并相应的设计一套视觉标定装置对相机视觉当量和旋转中心及传动比进行标定,主要内容如下:首先对一般设备机床的精度标定方法进行分析,并着重对机器视觉相机标定方法的研究现状进行了介绍。针对LED一体机需要进行标定的几个部分进行了分析,并就设备视觉相关的标定提出技术方案。建立视觉系统相机成像几何模型,分析镜头畸变对相机标定的影响。对视觉当量的标定方法进行了介绍,并设计一套标定装置对其进行标定,实验对比使用标定装置前后的标定效果。对偏角芯片角度校正的原理进行分析,通过最小二乘法拟合出供给区旋转中心坐标。采用标定板上圆点图案对旋转中心及传动比进行标定,并通过偏角芯片的角度校正实验验证了由视觉标定的传动比机械设计的传动比精度更高。最后,采用标定装置和原标定方法分别对视觉当量和旋转中心及传动比进行连续标定实验,并将标定结果进行对比。实验结果显示采用标定装置进行视觉标定时标定精度更高,而且耗时也明显短很多。
[Abstract]:In the process of LED chip production, the LED chip needs to be tested by photoelectric parameters before packaging, and then classified and sorted. The subsequent chip packaging requires high arrangement precision of the separated chip. In order to ensure the precision of chip arrangement, the LED integrated machine must be calibrated before it leaves the factory. However, the precision calibration of LED integrated machine is complicated, and the calibration efficiency is very low. In this paper, the visual calibration method of LED integrated machine is proposed, and a set of visual calibration device is designed to calibrate the camera visual equivalent, rotation center and transmission ratio. The main contents are as follows: firstly, the precision calibration method of machine tool is analyzed, and the research status of machine vision camera calibration method is introduced. This paper analyzes several parts of LED integrated machine which need to be calibrated, and puts forward the technical scheme of equipment vision related calibration. The geometric model of camera imaging in visual system is established, and the effect of lens distortion on camera calibration is analyzed. The calibration method of visual equivalent is introduced, and a set of calibration device is designed to calibrate it. The principle of angle correction is analyzed, and the rotation center coordinates of feed region are fitted by least square method. The rotation center and the transmission ratio are calibrated by using the dot pattern on the calibration board, and the accuracy of the transmission ratio designed by the vision calibration than the mechanical design is verified by the angle correction experiment of the deflection chip. Finally, the visual equivalent, the rotation center and the transmission ratio were calibrated continuously by the calibration device and the original calibration method, respectively, and the calibration results were compared. The experimental results show that the calibration accuracy is higher and the time consuming is much shorter.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP391.41;TN312.8

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