CN103438803B - Computer vision technique accurately measures the method for Rectangular Parts size across visual field - Google Patents

The invention discloses computer vision technique accurately measures Rectangular Parts size method across visual field; comprise: Rectangular Parts to be measured is positioned on rectangle reference block; axis of symmetry O and axis of symmetry O ' is parallel to each other or mutual α at a certain angle, and 0 °≤α & lt; 15 °; Guarantee that part does not exceed the edge of rectangle reference block; Utilize the length of rectangle reference block middle conductor EE ', FF ', GG ', HH ', EF, line segment EI, I in conjunction with utilizing the Computer Image Processing program that pre-sets accurately to detect ' E ', FJ, J ' F ', GK, K ' G ', HP, P ' H ' length, calculates the edge line size of Rectangular Parts to be measured.The precision of testing result of the present invention is high, and reduces the cost of detection system, can be applicable to accurately measure Rectangular Parts size.

计算机视觉技术跨视场精确测量矩形零件尺寸的方法A Method of Accurately Measuring the Dimensions of Rectangular Parts Across Fields of View Using Computer Vision Technology

技术领域technical field

本发明涉及计算机视觉精确测量领域，特指一种计算机视觉技术跨视野精确测量矩形零件尺寸的方法。The invention relates to the field of precise measurement of computer vision, in particular to a method for accurately measuring the size of rectangular parts across visual fields using computer vision technology.

背景技术Background technique

工业产品零件的实测尺寸是判断其质量的重要依据，控制零件的尺寸在设计的误差范围内是保证成品品质的重要手段。目前，工业产品零件尺寸的检测包括接触式测量方法和非接触式测量方法两大类。接触式测量方法主要有游标卡尺、千分尺、三坐标测量仪等，此类测量方法的结果虽然准确，但是测量过程耗时费力，容易碰伤、刮伤产品零件的表面，难以满足工业大生产的需求。非接触式测量方法主要有激光测量法和计算机视觉测量法，此类测量方法具有重现性好，检测速度快，容易实现在线检测等优势；其中计算机视觉测量方法能够对产品零件表面的多个尺寸参数进行同时检测，已被广泛运用于工业产品零件的尺寸检测。The measured size of industrial product parts is an important basis for judging its quality, and controlling the size of parts within the design error range is an important means to ensure the quality of finished products. At present, the detection of the size of industrial product parts includes two categories: contact measurement methods and non-contact measurement methods. Contact measurement methods mainly include vernier calipers, micrometers, three-coordinate measuring instruments, etc. Although the results of such measurement methods are accurate, the measurement process is time-consuming and laborious, and it is easy to bruise and scratch the surface of product parts, which is difficult to meet the needs of industrial mass production. . Non-contact measurement methods mainly include laser measurement method and computer vision measurement method. This type of measurement method has the advantages of good reproducibility, fast detection speed, and easy online detection; among them, computer vision measurement method can measure multiple parts on the surface of the product Simultaneous detection of dimensional parameters has been widely used in the dimensional detection of industrial product parts.

目前，计算机视觉已被用于精确检测固定视场内待测对象的细微特征。专利“一种高精度显微疲劳试验机”（申请号：200810207563.2）公开了一种利用计算机视觉检测微观裂纹尺寸的方法。该方法通过显微镜放大视场内试样疲劳裂纹区域的图像，经相机拍摄该视场下的图像并送入计算机，通过图像处理技术精确测量视场内试样裂纹的长度。当整条待测裂纹没有超出显微镜的视场时，该方法能够精确的测量裂纹的长度；当待测裂纹的某个部分超出了显微镜的视场时，则该方法难以测量裂纹的长度，因此该方法不能精确检测超出固定视场区域的细微特征。At present, computer vision has been used to accurately detect the subtle features of the object under test in a fixed field of view. The patent "A High-precision Microscopic Fatigue Testing Machine" (application number: 200810207563.2) discloses a method for detecting the size of microscopic cracks using computer vision. In this method, the image of the fatigue crack area of the sample in the field of view is amplified by a microscope, and the image in the field of view is captured by a camera and sent to a computer, and the length of the crack in the sample in the field of view is accurately measured by image processing technology. When the entire crack to be measured does not exceed the field of view of the microscope, this method can accurately measure the length of the crack; when a certain part of the crack to be measured exceeds the field of view of the microscope, this method is difficult to measure the length of the crack, so This method cannot accurately detect subtle features beyond the fixed field of view area.

在利用计算机视觉进行精确测量时，为了有效的捕捉试样的局部特征，相机或者显微镜的视场大小往往是受限的，视场的长或宽一般为2mm～5mm，而待测的特征参数如产品零件的长度、宽度、厚度等往往超出相机或显微镜的视场区域，如何跨视场精确检测上述特征参数是计算机视觉测量领域的难点。针对这一问题，专利“一种零件视觉检测装置”（申请号：200910079737.6）公开了一种计算机视觉跨视场检测零件表面缺陷及形貌尺寸的装置。该装置利用CCD相机与放大物镜等组成成像系统，将待测零件固定于位移台上，同时检测装置设有记录位移台移动距离的检测系统。该装置通过位移台将零件的边缘区域连续的送入成像系统的视场内，最终通过成像系统拍摄的零件边缘图像和位移检测系统记录的移动距离计算出零件的形貌尺寸。由于该装置的测量精度不仅与零件边缘图像的视觉识别精度有关，而且与位移检测系统对机械位移台行程的记录精度密切相关，因此不能实现高精度测量。专利“一种数码位移测量仪”（申请号：201120026446.3）公开了一种利用多个相机联用进行计算机视觉高精度测量的方法。该方法首先获取各个相机视场内待测对象局部区域的图像信息，然后利用图像拼接技术将各个相机获取的局部区域图像拼接成一幅待测对象的全景图像，进而利用计算机视觉技术对待测对象进行高精度测量。虽然该检测装置的测量精度不会受到机械位移台的影响，但是当待测参数比相机视场大几十倍、上百倍、甚至更多时，需要几十、上百甚至更多相机的联用才能完成测量，容易导致检测成本偏高。When computer vision is used for precise measurement, in order to effectively capture the local characteristics of the sample, the field of view of the camera or microscope is often limited. The length or width of the field of view is generally 2mm to 5mm, and the characteristic parameters to be measured For example, the length, width, and thickness of product parts often exceed the field of view of cameras or microscopes. How to accurately detect the above characteristic parameters across the field of view is a difficult point in the field of computer vision measurement. In response to this problem, the patent "A Part Visual Inspection Device" (application number: 200910079737.6) discloses a device for computer vision to detect surface defects and shape dimensions of parts across the field of view. The device uses a CCD camera and a magnifying objective lens to form an imaging system, and fixes the part to be tested on the translation platform. At the same time, the detection device is equipped with a detection system that records the moving distance of the translation platform. The device continuously sends the edge area of the part into the field of view of the imaging system through the translation stage, and finally calculates the shape and size of the part through the edge image of the part captured by the imaging system and the moving distance recorded by the displacement detection system. Since the measurement accuracy of this device is not only related to the visual recognition accuracy of the edge image of the part, but also closely related to the recording accuracy of the displacement detection system for the stroke of the mechanical displacement table, it cannot achieve high-precision measurement. The patent "A Digital Displacement Measuring Instrument" (Application No.: 201120026446.3) discloses a method for computer vision high-precision measurement using multiple cameras. This method first obtains the image information of the local area of the object to be measured in the field of view of each camera, and then uses the image stitching technology to stitch the local area images acquired by each camera into a panoramic image of the object to be measured, and then uses computer vision technology to monitor the object. High precision measurement. Although the measurement accuracy of the detection device will not be affected by the mechanical translation stage, when the parameter to be measured is dozens of times, hundreds of times, or even more than the field of view of the camera, it needs tens, hundreds, or even more cameras. The measurement can only be completed, which may easily lead to high detection costs.

发明内容Contents of the invention

本发明的目的在于提供计算机视觉技术跨视场精确测量矩形零件尺寸的方法，以实现对矩形零件的尺寸进行精确测量。The purpose of the present invention is to provide a method for accurately measuring the size of a rectangular part by computer vision technology across the field of view, so as to realize the precise measurement of the size of the rectangular part.

为了消除机械位移台对测量精度的影响以及有效控制检测系统的成本，本发明采用的技术方案如下：In order to eliminate the influence of the mechanical displacement platform on the measurement accuracy and effectively control the cost of the detection system, the technical scheme adopted in the present invention is as follows:

本发明是基于计算机视觉技术跨视野精确测量矩形零件尺寸的装置，包括矩形基准块ABCD、待测矩形零件A’B’C’D’、视觉成像系统、计算机、机械位移台组成；The present invention is a device for accurately measuring the dimensions of rectangular parts across visual fields based on computer vision technology.

所述矩形基准块ABCD的长宽比与待测矩形零件A’B’C’D’标准件的长宽比相同，且矩形基准块ABCD的面积比待测矩形零件A’B’C’D’标准件的面积大5%～20%；在矩形基准块ABCD上设置有两条水平方向的参考线EE’和FF’以及两条垂直方向的参考线GG’和HH’，且参考线EE’的长度L_EE’、参考线FF’的长度L_FF’、参考线GG’的长度L_GG’、参考线HH’的长度L_HH’、参考点E和参考点F之间的长度L_EF、参考点G和参考点H之间的长度L_GH、矩形基准块ABCD的四条边缘线AB、BC、CD、DA的长度L_AB、L_BC、L_CD、L_DA均为已知；虚线O为矩形基准块ABCD在垂直方向的对称轴；The aspect ratio of the rectangular reference block ABCD is the same as the aspect ratio of the rectangular part A'B'C'D' to be measured, and the area of the rectangular reference block ABCD is larger than that of the rectangular part A'B'C'D' to be measured. The area of the standard part is 5% to 20% larger; two reference lines EE' and FF' in the horizontal direction and two reference lines GG' and HH' in the vertical direction are set on the rectangular reference block ABCD, and the reference line EE The length L _EE' of ', the length L _FF' of reference line FF', the length L _GG' of reference line GG', the length L _HH' of reference line HH', the length L _EF between reference point E and reference point F , the length L _GH between the reference point G and the reference point H, the lengths L _AB , L _BC , L _CD , and L _DA of the four edge lines AB, BC, CD, and DA of the rectangular reference block ABCD are all known; the dotted line O is the symmetry axis of the rectangular datum block ABCD in the vertical direction;

所述待测矩形零件A’B’C’D’在垂直方向的对称轴为虚线O’；所述视觉成像系统由相机、镜头、光源、图像采集卡和数据传输线组成，且视觉成像系统固定安装于机械位移台上；所述的计算机内置预先开发的图像处理程序，能够获取、存储、处理视觉成像系统获取的图像；所述机械位移台能够携带视觉成像系统沿着设定的路径在矩形基准块ABCD的上方做水平运动。The symmetrical axis of the rectangular part A'B'C'D' to be measured in the vertical direction is a dotted line O'; the visual imaging system is composed of a camera, a lens, a light source, an image acquisition card and a data transmission line, and the visual imaging system is fixed Installed on a mechanical displacement platform; the computer has a built-in image processing program developed in advance, which can acquire, store, and process images acquired by the visual imaging system; the mechanical displacement platform can carry the visual imaging system along the set path in a rectangular Make a horizontal movement above the reference block ABCD.

基于计算机视觉技术跨视场精确测量矩形零件尺寸的方法，其特征在于包括以下步骤：The method for accurately measuring the size of a rectangular part across the field of view based on computer vision technology is characterized in that it comprises the following steps:

步骤一，将待测矩形零件A’B’C’D’放置于矩形基准块ABCD上，使得对称轴O与对称轴O’相互平行或者相互成一定的夹角α，且0°≤α<15°；Step 1. Place the rectangular part A'B'C'D' to be measured on the rectangular reference block ABCD so that the symmetry axis O and the symmetry axis O' are parallel to each other or form a certain angle α with each other, and 0°≤α< 15°;

步骤二，检查待测矩形零件A’B’C’D’的任何部分是否超出矩形基准块ABCD的边缘，具体分以下三个过程：Step 2, check whether any part of the rectangular part A'B'C'D' to be tested exceeds the edge of the rectangular reference block ABCD, specifically divided into the following three processes:

过程一，机械位移台携带视觉成像系统在距离矩形基准块ABCD上表面2mm～200mm的水平面内沿着A→B→C→D→A运动一周，移动的过程中视觉成像系统连续拍摄矩形基准块ABCD的四条边缘线AB、BC、CD、DA的图像，并存储于计算机；Process 1. The visual imaging system carried by the mechanical translation stage moves along A→B→C→D→A in a horizontal plane 2mm to 200mm from the upper surface of the rectangular reference block ABCD. During the movement, the visual imaging system continuously photographs the rectangular reference block The images of the four edge lines AB, BC, CD, DA of ABCD are stored in the computer;

过程二，计算机通过对矩形基准块ABCD的四条边缘线AB、BC、CD、DA的图像进行处理，判断边缘线AB、BC、CD、DA是否被待测矩形零件A’B’C’D’覆盖；Process 2. The computer processes the images of the four edge lines AB, BC, CD, and DA of the rectangular reference block ABCD to determine whether the edge lines AB, BC, CD, and DA are detected by the rectangular part A'B'C'D' cover;

过程三，如果边缘线AB、BC、CD、DA的任何一点被待测矩形零件A’B’C’D’覆盖，则返回步骤一；如果边缘线AB、BC、CD、DA的任何一点均没有被待测矩形零件A’B’C’D’覆盖，则进入步骤三；Process three, if any point of the edge lines AB, BC, CD, DA is covered by the rectangular part A'B'C'D' to be tested, return to step one; if any point of the edge lines AB, BC, CD, DA is covered by If it is not covered by the rectangular part A'B'C'D' to be tested, go to step 3;

步骤三，机械位移台携带视觉成像系统在距离矩形基准块ABCD上表面2mm～200mm的水平面内移动，分别获取参考线EE’、FF’、GG’、HH’未被待测矩形零件A’B’C’D’覆盖部分的图像，共拍摄8幅图像，拍摄过程使得线段EI、I’E’、FJ、J’F’、GK、K’G’、HP、P’H’完整出现在视觉成像系统的视场中。其中I、I’分别为参考线EE’与待测矩形零件边缘线A’D’、B’C’的交叉点，J、J’分别为参考线FF’与待测矩形零件边缘线A’D’、B’C’的交叉点，K、K’分别为参考线GG’与待测矩形零件边缘线A’B’、D’C’的交叉点，P、P’分别为参考线HH’与待测矩形零件边缘线A’B’、D’C’的交叉点；Step 3, the mechanical displacement stage carries the visual imaging system to move in the horizontal plane 2mm to 200mm away from the upper surface of the rectangular reference block ABCD, and respectively obtain the reference lines EE', FF', GG', HH' and the rectangular part A'B not to be tested The image covered by 'C'D', a total of 8 images were taken, and the shooting process made the line segments EI, I'E', FJ, J'F', GK, K'G', HP, P'H' completely appear in the In the field of view of the visual imaging system. Among them, I and I' are the intersection points of the reference line EE' and the edge lines A'D' and B'C' of the rectangular part to be measured, and J and J' are the reference line FF' and the edge line A' of the rectangular part to be measured respectively. The intersection points of D', B'C', K, K' are the intersection points of the reference line GG' and the edge lines A'B', D'C' of the rectangular part to be measured, respectively, and P, P' are the reference lines HH 'The intersection point with the edge lines A'B' and D'C' of the rectangular part to be measured;

步骤四，利用预先设置的计算机图像处理程序精确检测步骤三8幅图像中的线段长度，分别得到线段EI的长度L_EI、线段I’E’的长度L_I’E’、线段FJ的长度L_FJ、线段J’F’的长度L_J’F’、线段GK的长度L_GK、线段K’G’的长度L_K’G’、线段HP的长度L_HP、线段P’H’的长度L_P’H’；Step 4, use the pre-set computer image processing program to accurately detect the length of the line segment in the 8 images of Step 3, and obtain the length L _{EI of the line segment EI} , the length L _I'E' of the line segment I'E', and the length L of the line segment FJ respectively _FJ , length L of line segment J'F'_J'F' , length L _GK of line segment GK , length L _K'G' of line segment K'G' , length L _HP of line segment HP , length L of line segment P'H'_P'H';

步骤五，利用矩形基准块ABCD中线段EE’、FF’、GG’、HH’、EF的长度，结合步骤四中得到的线段EI、I’E’、FJ、J’F’、GK、K’G’、HP、P’H’的长度，计算待测矩形零件A’B’C’D’的边缘线尺寸L_A’B’和L_A’D’；Step five, using the lengths of the line segments EE', FF', GG', HH', EF in the rectangular reference block ABCD, combined with the line segments EI, I'E', FJ, J'F', GK, K obtained in step four The length of 'G', HP, P'H', calculate the edge line size L _A'B' and L _A'D' of the rectangular part A'B'C'D' to be measured;

所述待测矩形零件A’B’C’D’的边缘线尺寸L_A’B’和L_A’D’分以下两种方式计算：The edge line dimensions L _A'B' and L _A'D' of the rectangular part A'B'C'D' to be measured are calculated in the following two ways:

方式一：当满足条件时（0.0001<x<0.05），可认为矩形基准块ABCD的对称轴O与待测矩形零件A’B’C’D’的对称轴O’相互平行，则L_A’B’和L_A’D’的计算公式分别为：Method 1: When the conditions are met When (0.0001<x<0.05), it can be considered that the symmetry axis O of the rectangular reference block ABCD and the symmetry axis O' of the rectangular part A'B'C'D' to be measured are parallel to each other, then L _A'B' and L _A' The calculation formulas of _D' are:

L_A’B’=L_II’=L_EE’-L_EI-L_I’E’ L _A'B' =L _II' =L _EE' -L _EI -L _I'E'

L_A’D’=L_KK’=L_GG’-L_GK-L_K’G’ L _A'D' =L _KK' =L _GG' -L _GK -L _K'G'

方式二：当满足条件（0.0001<x<0.05）时，可认为矩形基准块ABCD的对称轴O与待测矩形零件A’B’C’D’的对称轴O’相互成一定的夹角α；为了确定夹角α的大小，以J为出发点向线段EI作垂线并与EI相交于Q点，则α=∠IJQ，由此可得 cos &alpha; = L JQ L JI = L JQ L JQ 2 + L QI 2 = L EF L EF 2 + ( L EI - L FJ ) 2 ; 由于夹角α的存在，使得LA’B’≠LII’，因此以I为出发点向B’C’作垂线并与B’C’相交于Q’点，且∠Q’II’=∠IJQ=α；则L_A’B’的计算公式为：Method 2: When the conditions are met (0.0001<x<0.05), it can be considered that the symmetry axis O of the rectangular reference block ABCD and the symmetry axis O' of the rectangular part A'B'C'D' to be measured form a certain angle α; in order to determine the angle α Take J as the starting point to draw a perpendicular line to the line segment EI and intersect EI at point Q, then α=∠IJQ, thus we can get cos &alpha; = L JQ L JI = L JQ L JQ 2 + L QI 2 = L EF L EF 2 + ( L EI - L FJ ) 2 ; Due to the existence of the included angle α, LA'B'≠LII', so take I as the starting point to draw a vertical line to B'C' and intersect B'C' at point Q', and ∠Q'II'=∠IJQ =α; then the calculation formula of L _A'B' is:

LL AA ,, BB ,, == LL IIII ,, &CenterDot;&Center Dot; coscos &alpha;&alpha; == (( LL EEEE ,, -- LL EIEI -- LL II ,, EE. ,, )) &CenterDot;&Center Dot; LL EFEF LL EFEF 22 ++ (( LL EIEI -- LL FJFJ )) 22

同理可得L_A’D’的计算公式为：In the same way, the calculation formula of L _A'D' can be obtained as follows:

LL AA ,, DD. ,, == LL KK KK ,, &CenterDot;&Center Dot; coscos &alpha;&alpha; == (( LL GGGG ,, -- LL GKGK -- LL KK ,, GG ,, )) &CenterDot;&Center Dot; LL EFEF LL EFEF 22 ++ (( LL EIEI -- LL FJFJ )) 22

本发明具有有益效果。本发明通过在矩形基准块上设置相应的参考点和参考线，结合计算机视觉技术对远大于视觉成像系统单个视场大小的矩形零件尺寸进行了精确测量。虽然在检测的过程中，需要机械移动平台携带视觉成像系统运动到矩形基准块的不同区域进行图像拍摄，但是在待测矩形尺寸的计算公式中并不需要输入机械移动平台的行程参数，因此检测结果的精度不再受到移动平台运动精度的影响。同时检测过程中不需要多个相机的协同即可完成大尺寸参数的跨视场精确测量，有效的控制了检测系统的成本。The invention has beneficial effects. The invention accurately measures the size of a rectangular part far larger than a single field of view of a visual imaging system by setting corresponding reference points and reference lines on a rectangular reference block and combining computer vision technology. Although in the process of detection, it is necessary for the mechanical mobile platform to carry the visual imaging system to move to different areas of the rectangular reference block for image capture, the calculation formula of the rectangular size to be measured does not need to input the stroke parameters of the mechanical mobile platform, so the detection The accuracy of the results is no longer affected by the motion accuracy of the moving platform. At the same time, the detection process does not require the cooperation of multiple cameras to complete the accurate measurement of large-scale parameters across the field of view, effectively controlling the cost of the detection system.

附图说明Description of drawings

图1为矩形基准块示意图；Fig. 1 is a schematic diagram of a rectangular reference block;

图2为待测矩形零件示意图；Fig. 2 is a schematic diagram of a rectangular part to be measured;

图3为计算机视觉跨视场精确测量矩形零件尺寸的示意图。Figure 3 is a schematic diagram of computer vision to accurately measure the size of a rectangular part across the field of view.

具体实施方式Detailed ways

以下通过各实施方式对本发明进行详细描述。但这些实施方式并不限制本发明，本领域的普通技术人员根据这些实施方式所做出的结构、方法、或功能上的变换均包含在本发明的保护范围内。The present invention will be described in detail through various embodiments below. However, these embodiments do not limit the present invention, and any structural, method, or functional changes made by those skilled in the art according to these embodiments are included in the protection scope of the present invention.

一种计算机视觉技术跨视野精确测量矩形零件尺寸的方法，包括矩形基准块ABCD、待测矩形零件A’B’C’D’、视觉成像系统、计算机、机械位移台组成。A method for accurately measuring the size of a rectangular part by computer vision technology, comprising a rectangular reference block ABCD, a rectangular part to be measured A'B'C'D', a visual imaging system, a computer, and a mechanical displacement platform.

如图1所示，矩形基准块ABCD与待测矩形零件A’B’C’D’标准件的长宽比均为1:2，且矩形基准块ABCD的面积比待测矩形零件A’B’C’D’标准件的面积大14.79%；参考线EE’的长度L_EE’=60mm、参考线FF’的长度L_FF’=60mm、参考线GG’的长度L_GG’=120mm、参考线HH’的长度L_HH’=120mm、参考点E和参考点F之间的长度L_EF=80mm、参考点G和参考点H之间的长度L_GH=35mm、矩形基准块ABCD的四条边缘线AB、BC、CD、DA的长度L_AB=L_CD=60mm、L_BC=L_DA=120mm；虚线O为矩形基准块ABCD在垂直方向的对称轴；As shown in Figure 1, the aspect ratio of the rectangular reference block ABCD and the standard rectangular part A'B'C'D' to be tested is 1:2, and the area of the rectangular reference block ABCD is larger than that of the rectangular part A'B to be measured The area of the 'C'D' standard part is 14.79% larger; the length of the reference line EE' L _EE' =60mm, the length of the reference line FF' L _FF' =60mm, the length of the reference line GG' L _GG' =120mm, the reference The length L HH' of the line HH _' =120mm, the length L _EF between the reference point E and the reference point F=80mm, the length _LGH =35mm between the reference point G and the reference point H, and the four edges of the rectangular datum block ABCD The lengths of lines AB, BC, CD, DA L _AB = L _CD = 60mm, L _BC = L _DA = 120mm; the dotted line O is the symmetry axis of the rectangular reference block ABCD in the vertical direction;

如图2所示，待测矩形零件A’B’C’D’在垂直方向的对称轴为虚线O’；As shown in Figure 2, the symmetrical axis of the rectangular part A'B'C'D' in the vertical direction is the dotted line O';

视觉成像系统中相机的型号为BasleracA1600-20gm、镜头的型号为OPTOTC2312、光源的型号为CSTCOL-040-R、图像采集卡的型号为ADLinkGIE64+；The model of the camera in the visual imaging system is BasleracA1600-20gm, the model of the lens is OPTOTC2312, the model of the light source is CSTCOL-040-R, and the model of the image acquisition card is ADLinkGIE64+;

机械位移台的型号为HY10DY(50-500)C，视觉成像系统固定安装于机械位移台上且相机镜头距离矩形基准块ABCD的距离为78mm；The model of the mechanical displacement stage is HY10DY(50-500)C, the visual imaging system is fixedly installed on the mechanical displacement stage and the distance between the camera lens and the rectangular reference block ABCD is 78mm;

本发明基于计算机视觉技术跨视野精确测量矩形零件尺寸的方法，测量过程的具体实施步骤如下。The present invention is based on computer vision technology to accurately measure the size of rectangular parts across the field of view. The specific implementation steps of the measurement process are as follows.

步骤一：将待测矩形零件A’B’C’D’放置于矩形基准块ABCD上，使得对称轴O与对称轴O’相互平行或者相互成一定的夹角α，即0°≤α<15°，如图3所示；Step 1: Place the rectangular part A'B'C'D' to be measured on the rectangular reference block ABCD so that the symmetry axis O and the symmetry axis O' are parallel to each other or form a certain angle α with each other, that is, 0°≤α< 15°, as shown in Figure 3;

步骤二：检查待测矩形零件A’B’C’D’的任何部分是否超出矩形基准块ABCD的边缘；Step 2: check whether any part of the rectangular part A'B'C'D' to be measured exceeds the edge of the rectangular reference block ABCD;

该步骤分以下三个过程：This step is divided into the following three processes:

过程（1）：机械位移台携带视觉成像系统在矩形基准块ABCD上表面一定高度的水平面沿着A→B→C→D→A运动一周，移动的过程中视觉成像系统连续拍摄矩形基准块ABCD的四条边缘线AB、BC、CD、DA的图像，并存储于计算机；Process (1): The visual imaging system carried by the mechanical translation stage moves along the horizontal plane of a certain height on the upper surface of the rectangular reference block ABCD along A→B→C→D→A for one week. During the movement process, the visual imaging system continuously takes pictures of the rectangular reference block ABCD The images of the four edge lines AB, BC, CD, DA are stored in the computer;

过程（2）：计算机通过对矩形基准块ABCD的四条边缘线AB、BC、CD、DA的图像进行处理，判断边缘线AB、BC、CD、DA是否被待测矩形零件A’B’C’D’覆盖；Process (2): The computer processes the images of the four edge lines AB, BC, CD, and DA of the rectangular reference block ABCD to determine whether the edge lines AB, BC, CD, and DA are detected by the rectangular part A'B'C' D' cover;

过程（3）：如果边缘线AB、BC、CD、DA的任何一点被待测矩形零件A’B’C’D’覆盖，则返回步骤一；如果边缘线AB、BC、CD、DA的任何一点均没有被待测矩形零件A’B’C’D’覆盖，则进入步骤三；Process (3): If any point of the edge line AB, BC, CD, DA is covered by the rectangular part A'B'C'D' to be tested, return to step 1; if any point of the edge line AB, BC, CD, DA If none of the points are covered by the rectangular part A'B'C'D' to be tested, go to step 3;

步骤三：机械位移台携带视觉成像系统在距离矩形基准块ABCD上表面一定高度的水平面内移动，分别获取参考线EE’、FF’、GG’、HH’未被待测矩形零件A’B’C’D’覆盖部分的图像，共拍摄8幅图像，拍摄过程使得线段EI、I’E’、FJ、J’F’、GK、K’G’、HP、P’H’完整出现在视觉成像系统的视场中。其中I、I’分别为参考线EE’与待测矩形零件边缘线A’D’、B’C’的交叉点，J、J’分别为参考线FF’与待测矩形零件边缘线A’D’、B’C’的交叉点，K、K’分别为参考线GG’与待测矩形零件边缘线A’B’、D’C’的交叉点，P、P’分别为参考线HH’与待测矩形零件边缘线A’B’、D’C’的交叉点；Step 3: The mechanical displacement stage carries the visual imaging system to move in the horizontal plane at a certain height from the upper surface of the rectangular reference block ABCD, and respectively obtain the reference lines EE', FF', GG', HH' and the rectangular part A'B' not to be measured C'D' covered part of the image, a total of 8 images were taken, and the shooting process made the line segments EI, I'E', FJ, J'F', GK, K'G', HP, P'H' completely appear in the visual in the field of view of the imaging system. Among them, I and I' are the intersection points of the reference line EE' and the edge lines A'D' and B'C' of the rectangular part to be measured, and J and J' are the reference line FF' and the edge line A' of the rectangular part to be measured respectively. The intersection points of D', B'C', K, K' are the intersection points of the reference line GG' and the edge lines A'B', D'C' of the rectangular part to be measured, respectively, and P, P' are the reference lines HH 'The intersection point with the edge lines A'B' and D'C' of the rectangular part to be measured;

步骤四：利用预先设置的计算机图像处理程序精确检测步骤三中8幅图像中的线段长度，分别得到线段EI的长度L_EI=2.5174mm、线段I’E’的长度L_I’E’=1.5436mm、线段FJ的长度L_FJ=1.5433mm、线段J’F’的长度L_J’F’=2.5171mm、线段GK的长度L_GK=3.2558mm、线段K’G’的长度L_K’G’=4.5354mm、线段HP的长度L_HP=4.5356mm、线段P’H’的长度L_P’H’=3.2554mm；Step 4: Use the pre-set computer image processing program to accurately detect the length of the line segment in the 8 images in step 3, and obtain the length L _EI =2.5174mm of the line segment EI and the length L _I'E' =1.5436 of the line segment I'E' respectively mm, the length of line segment FJ L _FJ =1.5433mm, the length of line segment J'F'L _J'F' =2.5171mm, the length of line segment GK L _GK =3.2558mm, the length of line segment K'G'L _K'G' =4.5354mm, the length L HP of line segment _HP =4.5356mm, the length L _{P'H' of line segment P'H'} =3.2554mm;

步骤五：将上述步骤中的已知参数代入发现其满足（即x的取值为0.01），所以按照以下公式计算待测矩形零件A’B’C’D’的边缘线尺寸L_A’B’和L_A’D’的值：Step 5: Substitute the known parameters in the above steps into found its satisfaction (That is, the value of x is 0.01), so calculate the values of the edge line dimensions L _A'B' and L _A'D' of the rectangular part A'B'C'D' to be measured according to the following formula:

LL AA ,, BB ,, == LL IIII ,, &CenterDot;&Center Dot; coscos &alpha;&alpha; == (( LL EEEE ,, -- LL EIEI -- LL II ,, EE. ,, )) &CenterDot;&Center Dot; LL EFEF LL EFEF 22 ++ (( LL EIEI -- LL FJFJ )) 22

LL AA ,, DD. ,, == LL KK KK ,, &CenterDot;&Center Dot; coscos &alpha;&alpha; == (( LL GGGG ,, -- LL GKGK -- LL KK ,, GG ,, )) &CenterDot;&Center Dot; LL EFEF LL EFEF 22 ++ (( LL EIEI -- LL FJFJ )) 22

其中in

coscos &alpha;&alpha; == LL JQJQ LL JIJI == LL JQJQ LL JQJQ 22 ++ LL QIQI 22 == LL EFEF LL EFEF 22 ++ (( LL EIEI -- LL FJFJ )) 22 == 8080 8080 22 ++ (( 2.51742.5174 -- 1.54331.5433 )) 22 == 0.9999260.999926

将已知参数代入L_A’B’和L_A’D’的计算公式，得到L_A’B’=55.9349mm，L_A’D’=112.2005mm。计算得到的L_A’B’和L_A’D’长度与机械位移台的行程无关，因此本发明提供的矩形零件尺寸检测方法不会受到机械位移台运动精度的影响，能够利用计算机视觉精确测量零件的尺寸。Substituting the known parameters into the calculation formula of _LA'B' and _LA'D' , it is obtained that _LA'B' =55.9349mm, _LA'D' =112.2005mm. The calculated L _A'B' and L _A'D' lengths have nothing to do with the stroke of the mechanical displacement platform, so the method for detecting the size of rectangular parts provided by the present invention will not be affected by the motion accuracy of the mechanical displacement platform, and can be accurately measured by computer vision The dimensions of the part.