摘要针对当前航天用O形密封圈存在的测量精度低、效率低等问题，本文研制一套基于机器视觉的尺寸测量系统。首先简要地介绍了基于机器视觉的尺寸测量系统的工作原理；然后在分析O形圈周长不变的基础上提出一种基于拟合曲线的测量算法，并介绍利用这种算法解决O形圈测量问题的原理和实现步骤；最后进行了实验，并对测量误差进行了分析，给出了测量结果的不确定度。实验结果表明，本系统能够对外形尺寸为Φ5.4～Φ140mm的O形圈进行智能化自主测量，内径的重复精度不超过33μm，截面直径的重复精度不超过4μm，能够满足航天用精密密封圈的智能、高效、全自动测量要求。47865

毕业论文关键词  尺寸测量  机器视觉  拟合算法

毕业设计说明书外文摘要

Title  The size measuring system of intelligent measurement and detection equipment for sealing rings used in ae-rospace systems                                      

Abstract

In view of the current problems of low measuring accuracy and low efficiency with ‘o’ rings in aerospace, a set of measurement system based on machine vision was developed in this paper. First, the working principle of the size measurement system based on machine vision was briefly introduced. Then on the basis of analyzing that the circumference of ‘o’ rings is constant, a kind of measuring algorithm based on curve fitting was put forward, and the principle and implementation steps of solving the measuring problems of the ‘o’ rings taking advantage of this algorithm were introduced. Finally an experiment was carried on.The error of measurement was analyzed and the uncertainty of measurement results was given. The experimental results showed that the system is able to conduct intelligent independent measurement for ‘o’ rings whose outer diameters are from 5.4 millimeters to 140 millimeters. The repeat precision of inner diameters is less than thirty-three microns, and that of diameters of cross section is less than four microns. The system can satisfy smart, efficient, automatic measurement requirements for precise sealing rings in aerospace. 

Keywords  size measurement  machine vision  fitting algorithm

目   次

1  引言 1

1.1  课题背景及意义 1

1.2  密封圈测量技术研究现状 1

1.3  主要研究内容 3

2  基于机器视觉的尺寸测量系统 4

2.1  技术要求 4

2.2  系统方案 4

3  尺寸测量算法的设计 10

3.1  图像的二值化分割 10

3.2  轮廓提取与边界跟踪 11

3.3  边缘曲线的处理 13

3.3.1  划分闭合边缘 13

3.3.2  拟合边缘曲线 16

3.3.3  内外边缘的插值 18

3.3.4  绘制小径分布图 20

4  测量实验与数据分析处理 23

4.1  系统标定 23

4.2  实验结果与讨论 24

4.3  误差分析