CN102207371B - Three-dimensional point coordinate measuring method and measuring apparatus thereof - Google Patents

一种三维点坐标测量方法及测量装置，解决系统的柔性和测量速度，满足现场测量和不易测量点的测量和降低制造成本的问题，方法的方案是，建立摄像机坐标系，标定出测量探头固定标志点的在光笔坐标系的三维坐标，计算出测量探头上一组固定标志点在摄像机坐标系坐标系下实施测量时刻的空间三维坐标和测量探头坐标系下的三维坐标，建立实施测量时刻两个坐标系的逻辑关系，标定球形测头的球心点在测量探头坐标系的三维坐标，利用前述结果，在测量时刻测算出测量探头前端球形测量头与被测点接触获测量点的坐标。测量装置，包括支架、摄像机、测量探头和配套的计算机和配套软件构成，摄像机为两台,固定在支架上，球形测量头固定在T形杆的前端，一组标志点呈T形固定在T形杆上。其优点是，柔性好和测量速度快，可实施不易测量点的测量和成本低。

A three-dimensional point coordinate measurement method and measurement device, which solve the problems of system flexibility and measurement speed, meet the problems of on-site measurement and measurement of difficult-to-measure points, and reduce manufacturing costs. The solution of the method is to establish a camera coordinate system and calibrate the measurement probe to fix The three-dimensional coordinates of the marker points in the coordinate system of the light pen are calculated to calculate the spatial three-dimensional coordinates of a group of fixed marker points on the measuring probe at the time of measurement under the coordinate system of the camera coordinate system and the three-dimensional coordinates of the coordinate system of the measuring probe, and establish two points at the time of measuring. The logical relationship between the two coordinate systems is to calibrate the three-dimensional coordinates of the spherical center point of the spherical probe in the coordinate system of the measuring probe. Using the aforementioned results, the coordinates of the measuring point obtained by contacting the spherical measuring head at the front end of the measuring probe with the measured point are calculated at the measurement time. The measuring device consists of a bracket, a camera, a measuring probe, a supporting computer and supporting software. There are two cameras fixed on the bracket, the spherical measuring head is fixed on the front end of the T-shaped bar, and a group of marking points are fixed on the T shape bar. The advantage is that it has good flexibility and fast measurement speed, can implement measurement of difficult measurement points, and has low cost.

一种三维点坐标测量方法及测量装置A three-dimensional point coordinate measuring method and measuring device

技术领域 technical field

本发明属于精密测量领域，将接触式测量和非接触式测量这两种方法有机结合，特别是一种测量探头和任意移动的便携式三维坐标测量方法及测量装置。 The invention belongs to the field of precision measurement and organically combines two methods of contact measurement and non-contact measurement, in particular a measurement probe and a portable three-dimensional coordinate measurement method and a measurement device which can move arbitrarily.

背景技术 Background technique

三坐标测量机方面已经非常成熟，根据目前的测量设备的发展状况，按通常的分类，可以把测量系统分为三坐标测量系统、柔性三坐标测量系统和以三维激光扫描测量系统、光学照相扫描测量系统等为代表的结构光扫描测量系统等。接触式的三坐标测量系统测量技术已经非常成熟，即使是结构光扫描三维测量手段日益普及的今天，传统CMM仍是占市场份额最大的三维测量手段。一般来讲，传统CMM具有精度高、可靠性好、技术成熟等特点，但测量速度慢、对被测物体的大小和重量有一定要求，并且需要比较严格的实验室环境。所以，测点量要求较少的标准件的高精度测量一般都采用传统CMM。 The three-coordinate measuring machine has been very mature. According to the current development of measuring equipment, according to the usual classification, the measurement system can be divided into three-coordinate measurement system, flexible three-coordinate measurement system and three-dimensional laser scanning measurement system, optical photo scanning The structured light scanning measurement system represented by the measurement system and the like. The measurement technology of the contact three-coordinate measurement system is very mature. Even today, the three-dimensional measurement method of structured light scanning is becoming more and more popular, and the traditional CMM is still the three-dimensional measurement method with the largest market share. Generally speaking, the traditional CMM has the characteristics of high precision, good reliability, and mature technology, but the measurement speed is slow, there are certain requirements for the size and weight of the measured object, and a relatively strict laboratory environment is required. Therefore, traditional CMMs are generally used for high-precision measurement of standard parts that require fewer measuring points.

目前柔性测量臂的研制开发已成为逆向工程研究的热点。世界上柔性测量臂制造厂有十多家，主要的有：美国CIMCORE（ROMER-USA）、法国ROMER公司、美国FARO公司、日本Vectron公司，德国ZettMess公司、意大利的Garda公司等。 At present, the research and development of flexible measuring arm has become a hot spot in reverse engineering research. There are more than ten flexible measuring arm manufacturers in the world, the main ones are: American CIMCORE (ROMER-USA), French ROMER, American FARO, Japanese Vectron, German ZettMess, Italian Garda, etc.

上述的便携式三坐标测量机相对于传统的三坐标测量机具有更好的便携性、灵活性和现场检测能力，因此大大降低了对测量环境的限制，扩大了三维测量的应用场合。但是，现有柔性测量臂具有制造成本高，设备复杂，对测量现场要求较高，一次测量范围受到臂长的限制，测量速度慢，测量效率低等弱点。 Compared with the traditional three-dimensional measuring machine, the above-mentioned portable three-dimensional measuring machine has better portability, flexibility and on-site detection ability, so it greatly reduces the limitation on the measurement environment and expands the application occasions of three-dimensional measurement. However, the existing flexible measuring arm has the disadvantages of high manufacturing cost, complex equipment, high requirements on the measurement site, the limitation of the length of the arm for one measurement, slow measurement speed and low measurement efficiency.

以三维激光扫描测量系统和光学照相扫描测量系统等为代表的结构光扫描测量系统，具有测量速度快的优点，能够在短时间内获取大量的测量数据，但是却有两个重大的缺点，一是无法进行单点测量，不能有选择的、单独的获取某些点的坐标；二是有断光干扰，不能对深孔、遮光部分等位置进行测量。 The structured light scanning measurement system represented by the three-dimensional laser scanning measurement system and the optical photographic scanning measurement system has the advantage of fast measurement speed and can obtain a large amount of measurement data in a short time, but it has two major shortcomings. It is impossible to perform single-point measurement, and the coordinates of certain points cannot be obtained selectively and separately; second, there is light-off interference, and it is impossible to measure deep holes, shading parts, etc.

发明内容 Contents of the invention

为更好发挥便携式三坐标测量使用方便的优势，同时提高测量系统的柔性和测量速度，并尽可能满足各种现场测量，更适应对深孔、遮光部分等不易测量点的测量和降低便携式三坐标测量仪器的制造成本，本发明公开一种三维点坐标测量方法及测量装置，该方法结合接触式测量和非接触式测量这两种方法，建立的数学模型通过测量探头与被测点接触，对检测点三维坐标进行确定。有效地克服目前三坐标测量机柔性低、造价高以及非接触式扫描仪不能探测内表面等遮光部分、能够单独测量某个点的缺陷。 In order to take advantage of the convenience of portable three-coordinate measurement, improve the flexibility and measurement speed of the measurement system, and meet various on-site measurements as much as possible, it is more suitable for the measurement of difficult-to-measure points such as deep holes and shading parts, and reduces the cost of portable three-coordinate measurement. Coordinate measuring instrument manufacturing cost, the invention discloses a three-dimensional point coordinate measuring method and measuring device, the method combines the two methods of contact measurement and non-contact measurement, and the established mathematical model is in contact with the measured point through the measurement probe, Determine the three-dimensional coordinates of the detection point. It effectively overcomes the defects of low flexibility and high cost of the current three-coordinate measuring machine, and the non-contact scanner cannot detect the shading part such as the inner surface, and can measure a certain point independently.

本发明实现测量方法的发明目的采用的技术方案是，一种三维点坐标测量方法，该方法是通过测量探头与被测点接触，两台CCD摄像机采集测量探头部分图像信息，通过配套的计算机软件确定被测点的三维点坐，该方法通过以下步骤实现： The technical solution adopted by the present invention to realize the invention purpose of the measurement method is a three-dimensional point coordinate measurement method. The method is to contact the measured point through the measurement probe, and two CCD cameras collect part of the image information of the measurement probe, and through the supporting computer software To determine the three-dimensional coordinates of the measured point, the method is implemented through the following steps:

⑴、建立摄像机坐标系，对固定设置的两台CCD摄相机，利用相机自标定算法，解算出摄相机的内部参数和两个摄相机的相对方位，从而建立摄相机坐标系； (1) Establish a camera coordinate system, and use the camera self-calibration algorithm to calculate the internal parameters of the camera and the relative orientation of the two cameras for the two fixedly installed CCD cameras, thereby establishing the camera coordinate system;

⑵、根据双目立体视觉匹配算法计算出测量探头上固定设置的一组标志点Pg1-PgN在摄像机坐标系下实施测量时刻的空间三维坐标，采用光束法平差的原理标定测量探头上固定设置的该组标志点Pg1-PgN在测量探头坐标系下的三维坐标； ⑵. According to the binocular stereo vision matching algorithm, calculate the three-dimensional coordinates of a set of marker points Pg1-PgN fixedly set on the measuring probe at the time of measurement in the camera coordinate system, and use the principle of beam adjustment to calibrate the fixed setting on the measuring probe The three-dimensional coordinates of the group of marker points Pg1-PgN in the measuring probe coordinate system;

⑶、通过一组固定在测量探头上点Pg1-PgN在探头坐标系下的三维坐标和实施测量时刻在摄像机坐标系下的三维坐标，可以确定实施测量时刻的测量探头坐标系相对于摄像机坐标系的旋转矩阵R和平移向量T，从而建立实施测量时刻两个坐标系的逻辑关系； (3) Through a group of three-dimensional coordinates of points Pg1-PgN fixed on the measuring probe under the probe coordinate system and the three-dimensional coordinates under the camera coordinate system at the time of measurement, the coordinate system of the measuring probe at the time of measurement can be determined relative to the camera coordinate system The rotation matrix R and the translation vector T of the rotation matrix, so as to establish the logical relationship between the two coordinate systems at the moment of measurement;

⑷、采用测量探头单点多姿态的标定算法，来标定出测量探头前端球形测头的球心点Pg在测量头坐标系的三维坐标； ⑷. Use the single-point multi-attitude calibration algorithm of the measuring probe to calibrate the three-dimensional coordinates of the spherical center point Pg of the spherical probe at the front end of the measuring probe in the measuring head coordinate system;

⑸、在测量的时候，测量探头前端球形测量头与被测点接触，两台CCD摄像机采集测量探头上不少于3个以上标志点的图像信息，配套的计算机软件重复步骤（3）建立测量时刻的两个坐标系的逻辑关系并利用步骤（4）的标定结果，即可实时获得测量探头前端球形测量头的球心点Pg在摄像机坐标系下的三维坐标，配套的计算机软件在通过测量探头前端球形测量头的球心点Pg的三维坐标值确定被测点在摄像机坐标系中的三维坐标，并保存在配套的计算机的数据库中，重复上述测量过程，可以完成对n个测量点的测量。 ⑸ When measuring, the spherical measuring head at the front end of the measuring probe is in contact with the measured point, two CCD cameras collect the image information of no less than 3 mark points on the measuring probe, and the supporting computer software repeats step (3) to establish the measurement The logical relationship between the two coordinate systems at each moment and the calibration results of step (4) can be used to obtain the three-dimensional coordinates of the spherical center point Pg of the spherical measuring head at the front end of the measuring probe in the camera coordinate system in real time. The three-dimensional coordinates of the spherical center point Pg of the spherical measuring head at the front end of the probe determine the three-dimensional coordinates of the measured point in the camera coordinate system, and store them in the database of the supporting computer. Repeat the above measurement process to complete the measurement of n measurement points. Measurement.

本发明实现测量装置的发明目的采用的技术方案是，一种三维点坐标测量装置，包括支架、CCD摄像机、测量探头和配套的计算机和配套软件构成，配套软件是采用本发明所述的三维点坐标测量方法实现的，所述的CCD摄像机为两台,并固定在支架上，所述的测量探头包括T形杆、球形测量头和一组标志点，球形测量头固定在T形杆的前端，一组标志点呈T形固定在T形杆上。 The technical solution adopted by the present invention to realize the purpose of the invention of the measuring device is that a three-dimensional point coordinate measuring device comprises a support, a CCD camera, a measuring probe, a supporting computer and supporting software, and the supporting software adopts the three-dimensional point coordinates described in the present invention. Coordinate measurement method is realized, and described CCD camera is two, and is fixed on the bracket, and described measuring probe comprises T-shaped rod, spherical measuring head and a group of marking points, and spherical measuring head is fixed on the front end of T-shaped rod , a group of marker points are fixed on the T-shaped bar in a T-shape.

本发明的有益效果是，测量探头可以灵活探测到各种内外表面的点，如可以伸入深孔、内表面等，而测量探头上的标志点暴露于CCD摄像机可探测到的区域。本发明作为三坐标测量以及非接触式测量的有力补充，扩大了物体的测量范围。本发明测量系统简单可靠，又可以消除非接触式测量时的测量死角，具有体积小、重量轻、测量范围大、使用灵活方便、便于携带及现场使用等突出优点。 The beneficial effect of the present invention is that the measuring probe can flexibly detect various points on the inner and outer surfaces, such as extending into deep holes, inner surfaces, etc., and the marking points on the measuring probe are exposed to the detectable area of the CCD camera. As a powerful supplement to three-coordinate measurement and non-contact measurement, the invention expands the measurement range of objects. The measurement system of the present invention is simple and reliable, and can eliminate the measurement dead angle during non-contact measurement, and has the outstanding advantages of small size, light weight, large measurement range, flexible and convenient use, easy to carry and use on site.

本发明的与其它测量系统相比具有一些优点： The present invention has some advantages over other measurement systems:

（1）测量探头、CCD摄像机和被测物体三者之间或摄像机与摄像机之间不需要严格精确的安装定位，因此可根据被测物体特点灵活调整摄像机的位置，大大方便了现场使用，增强了系统的柔性。 (1) There is no need for strict and precise installation and positioning between the measuring probe, the CCD camera and the measured object, or between the camera and the camera. Therefore, the position of the camera can be flexibly adjusted according to the characteristics of the measured object, which greatly facilitates on-site use and enhances System flexibility.

（2）测量探头和视觉测量系统的结合提供了传统三坐标测量机的所有优点,并且不带来任何限制。同时,该系统的适用性鼓励了广泛领域的操作者，他们不必是操作视觉检测系统的照相测量专家。传统的三坐标测量机,以及参考系统,移动部分,和很难操纵的操纵杆系统,不能提供对任意选中点的及时,简易的测量,但这对于测量探头来说,是很容易做到的。 (2) The combination of measuring probe and visual measuring system provides all the advantages of traditional CMM without any limitation. Also, the applicability of the system encourages a wide range of operators who do not have to be photogrammetry experts to operate a vision inspection system. Traditional coordinate measuring machines, with reference systems, moving parts, and joystick systems that are difficult to maneuver, cannot provide timely and easy measurements of arbitrary selected points, but this is easily done with measuring probes .

（3）测量探头、摄像机和被测物体三者之间不需要严格精确的安装定位，因此可根据被测物体特点灵活调整摄像机的位置，方便现场使用，增强了系统的柔性。 (3) There is no need for strict and precise installation and positioning among the measuring probe, the camera and the measured object, so the position of the camera can be flexibly adjusted according to the characteristics of the measured object, which is convenient for on-site use and enhances the flexibility of the system.

（4）摄像机摄取得是测量探头上标志点的图像而不是测点处的图像，所以测量不受被测物体表面的几何形状、表面曲率和材质的影响，这是以往的光学测量法最为头痛的事。而且有些难测的位置或盲点，可通过改变测量探头的长度和形状来进行测量。 (4) The image taken by the camera is the image of the mark point on the measuring probe instead of the image at the measuring point, so the measurement is not affected by the geometry, surface curvature and material of the surface of the measured object, which is the most troublesome optical measurement method in the past thing. And some difficult-to-measure positions or blind spots can be measured by changing the length and shape of the measuring probe.

下面结合附图对本发明进行详细描述。 The present invention will be described in detail below in conjunction with the accompanying drawings.

附图说明 Description of drawings

附图1为本发明的装置示意图。 Accompanying drawing 1 is the device diagram of the present invention.

附图2为测量探头示意图。 Accompanying drawing 2 is the schematic diagram of measuring probe.

附图中，1、CCD摄像机，2、支架，3测量探头，3-1、T形杆、3-2、球形测量头，Pg1-PgN、标志点，4、计算机。 In the accompanying drawings, 1. CCD camera, 2. bracket, 3. measuring probe, 3-1. T-shaped bar, 3-2. spherical measuring head, Pg1-PgN, marking points, 4. computer.

具体实施方式 Detailed ways

一种三维点坐标测量方法，该方法是通过测量探头与被测点接触，两台CCD摄像机采集测量探头图像信息，通过配套的计算机软件确定被测点的三维点坐，该方法通过以下步骤实现： A method for measuring three-dimensional point coordinates, the method is to contact the measured point with the measuring probe, two CCD cameras collect the image information of the measuring probe, and determine the three-dimensional point coordinates of the measured point through the supporting computer software, the method is realized through the following steps :

⑴、建立摄像机坐标系，对固定设置的两台CCD摄相机，利用相机自标定算法，解算出摄相机的内部参数和两个摄相机的相对方位，从而建立摄相机坐标系。 (1) Establish a camera coordinate system. For two fixed CCD cameras, use the camera self-calibration algorithm to calculate the internal parameters of the camera and the relative orientation of the two cameras, thereby establishing the camera coordinate system.

⑵、根据双目立体视觉匹配算法计算出测量探头上固定设置的一组标志点Pg1-PgN在摄像机坐标系坐标系下实施测量时刻的空间三维坐标，采用光束法平差的原理标定测量探头上固定设置的该组标志点Pg1-PgN在测量探头坐标系下的三维坐标。 ⑵. According to the binocular stereo vision matching algorithm, calculate the three-dimensional coordinates of a set of marker points Pg1-PgN fixedly set on the measuring probe at the time of measurement in the camera coordinate system coordinate system, and use the principle of beam adjustment to calibrate the measuring probe. The fixedly set three-dimensional coordinates of the group of marker points Pg1-PgN in the measuring probe coordinate system.

标定出在测量探头坐标系下一组标志点的三维坐标Pg1（xg1，yg1，zg1），Pg2（xg2，yg2，zg2），…，PgN（xgN，ygN，zgN）。本发明实施例中，一组标志点设置为5个，即N=5。 Calibrate the three-dimensional coordinates Pg1 (xg1, yg1, zg1), Pg2 (xg2, yg2, zg2), ..., PgN (xgN, ygN, zgN) of a group of marker points in the measuring probe coordinate system. In the embodiment of the present invention, a set of marker points is set to 5, that is, N=5.

⑶、通过一组固定在测量探头上的标志点Pg1-PgN，在探头坐标系下的三维坐标和实施测量时刻在摄像机坐标系的三维坐标，可以确定实施测量时刻的测量探头坐标系相对于摄像机坐标系的旋转矩阵R和平移向量T，从而建立实施测量时刻两个坐标系的逻辑关系。 ⑶. Through a group of marker points Pg1-PgN fixed on the measuring probe, the three-dimensional coordinates in the probe coordinate system and the three-dimensional coordinates in the camera coordinate system at the time of measurement, the coordinate system of the measuring probe at the time of measurement can be determined relative to the camera The rotation matrix R and the translation vector T of the coordinate system, so as to establish the logical relationship between the two coordinate systems at the time of measurement.

⑷、采用测量探头单点多姿态的标定算法，来标定出测量头前端球形测量头的球心点Pg在测量头坐标系的三维坐标。 ⑷. Use the single-point multi-attitude calibration algorithm of the measuring probe to calibrate the three-dimensional coordinates of the spherical center point Pg of the spherical measuring head at the front end of the measuring head in the measuring head coordinate system.

所述的测量探头单点多姿态的标定算法，是采用测量探头前端球形测量头的球心Pg点的标定则采用单点多姿态的自标定方法进行标定。将球形测量头的球心Pg点放置到标定块的圆锥孔内，对圆锥孔的设计要求是要保证球形测量头不会触底，同时要保证球形测量头位置在旋转、倾斜一定角度的情况下，测量探头除球形测量头之外的其他任何部分不会接触到圆锥孔的侧壁。把球形测量头放入圆锥孔后，保证球形测量头和锥孔的四周充分完全接触，这样在测量探头倾斜一定角度后，球形测量头的中心点Pg的空间位置没有发生任何改变。 The single-point multi-attitude calibration algorithm of the measuring probe adopts the self-calibration method of the single-point multi-attitude self-calibration method to calibrate the spherical center Pg point of the spherical measuring head at the front end of the measuring probe. Place the center point Pg of the spherical measuring head into the conical hole of the calibration block. The design requirement for the conical hole is to ensure that the spherical measuring head does not touch the bottom, and at the same time ensure that the position of the spherical measuring head is rotated or tilted at a certain angle. Next, any part of the measuring probe other than the spherical measuring head does not touch the side wall of the tapered hole. After putting the spherical measuring head into the tapered hole, ensure that the spherical measuring head is fully in contact with the surrounding of the tapered hole, so that after the measuring probe is tilted at a certain angle, the spatial position of the center point Pg of the spherical measuring head does not change.

在球形测量头中心点Pg的同一个位置获得了测量探头的n个姿态，两台CCD摄像机采集获得了n对球形测量头图像，那么通过双目立体视觉测量算法，就可以获得n组测量探头标志点Pg1~PgN在摄像机坐标系下的三维坐标（以下公式中标志点设置5个，即N=5）： At the same position of the center point Pg of the spherical measuring head, n attitudes of the measuring probe are obtained, and n pairs of images of the spherical measuring head are collected by two CCD cameras. Then, through the binocular stereo vision measurement algorithm, n groups of measuring probes can be obtained The three-dimensional coordinates of the marker points Pg1~PgN in the camera coordinate system (set 5 marker points in the following formula, that is, N=5):

，i=1，2，…，n-1，n。

, i=1, 2,..., n-1, n.

再根据此前通过标定获得的球形测量头上N个标志点Pg1~PgN在球形测量头坐标系下面的三维空间坐标： Then according to the three-dimensional space coordinates of the N mark points Pg1~PgN on the spherical measuring head obtained through calibration before under the coordinate system of the spherical measuring head:

，i=1，2，…，n-1，n。

, i=1, 2,..., n-1, n.

便可得到方程： The equation can be obtained:

 （1） (1)

为了得到测量探头相对于摄像机的姿态，通过SVD法求出上述方程（1）测量探头坐标系相对于摄像机坐标系的旋转矩阵R和平移向量T。 In order to obtain the attitude of the measuring probe relative to the camera, the above equation (1) the rotation matrix R and the translation vector T of the measuring probe coordinate system relative to the camera coordinate system are obtained by the SVD method.

先设球形测量头中心点Pg在测量探头坐标系的坐标为Pg=[xgp，ygp，zgp]^T，在摄像机坐标系的坐标为Pc=[xgc，ygc，zgc]^T，则根据式(1)可得到如下方程组： First set the coordinates of the center point Pg of the spherical measuring head in the measuring probe coordinate system as Pg=[xgp, ygp, zgp] ^T , and the coordinates in the camera coordinate system as Pc=[xgc, ygc, zgc] ^T , then according to formula (1 ) can get the following equations:

                                （2）

(2)

由于方程组是个线性方程组，未知数为3个，因此只要n≥2即可解算出Pg，为了增加稳定性和可靠性，本系统两台CCD摄像机拍摄至少6组共12幅图像，通过最小二乘法来求球形测量头中心点在测量探头坐标系的坐标Pg。 Since the system of equations is a system of linear equations with 3 unknowns, Pg can be calculated as long as n≥2. In order to increase stability and reliability, two CCD cameras in this system take at least 6 groups of 12 images. Multiply to find the coordinate Pg of the center point of the spherical measuring head in the measuring probe coordinate system.

标定出了Pg后，在实际测量中，即可代入式(1)中，求出球形测量头中心在摄像机坐标系的坐标，即可得到被测物体点的三维坐标。从而实现了基于双目立体视觉的接触式测量。 After the Pg is calibrated, in the actual measurement, it can be substituted into formula (1) to obtain the coordinates of the center of the spherical measuring head in the camera coordinate system, and then the three-dimensional coordinates of the measured object point can be obtained. Thus, the contact measurement based on binocular stereo vision is realized.

⑸、在测量的时候，测量探头前端球形测量头与被测点接触，两台CCD摄像机采集测量探头上不少于3个标志点的图像信息，配套的计算机软件重复步骤（3）建立测量时刻的两个坐标系的逻辑关系并利用步骤（4）的标定结果，即可实时获得测量探头前端球形测量头的球心点Pg在摄像机坐标系下的三维坐标，配套的计算机软件在通过测量探头前端球形测量头的球心点Pg的三维坐标值确定被测点在摄像机坐标系中的三维坐标，并保存在配套的计算机的数据库中，重复上述测量过程，可以完成对n个测量点的测量。 ⑸ When measuring, the spherical measuring head at the front end of the measuring probe is in contact with the measured point, two CCD cameras collect the image information of no less than 3 mark points on the measuring probe, and the matching computer software repeats step (3) to establish the measuring time The logical relationship between the two coordinate systems and the calibration results of step (4) can be used to obtain the three-dimensional coordinates of the spherical center point Pg of the spherical measuring head at the front end of the measuring probe in the camera coordinate system in real time. The supporting computer software passes the measuring probe The three-dimensional coordinates of the center point Pg of the front-end spherical measuring head determine the three-dimensional coordinates of the measured point in the camera coordinate system, and save it in the database of the supporting computer. Repeat the above measurement process to complete the measurement of n measurement points .

本发明依据上述方法，设计的一种三维点坐标测量装置，包括支架、CCD摄像机、测量探头和配套的计算机和配套软件构成，配套软件是采用权利要求1所述的三维点坐标测量方法实现的，所述的CCD摄像机1为两台,并固定在支架2上，所述的测量探头3包括T形杆3-1、球形测量头3-2和一组标志点Pg1-PgN，球形测量头3-2固定在T形杆3-1的前端，一组标志点Pg1-PgN呈T形固定在T形杆3-1上。所述一组标志点Pg1-PgN不少于3个。 According to the above method, the present invention designs a three-dimensional point coordinate measuring device, comprising a support, a CCD camera, a measuring probe, a supporting computer and supporting software, and the supporting software is realized by using the three-dimensional point coordinate measuring method described in claim 1 , the CCD camera 1 is two, and fixed on the bracket 2, the measurement probe 3 includes a T-shaped bar 3-1, a spherical measuring head 3-2 and a group of marker points Pg1-PgN, the spherical measuring head 3-2 is fixed on the front end of the T-shaped bar 3-1, and a group of marking points Pg1-PgN is fixed on the T-shaped bar 3-1 in a T-shape. The set of marker points Pg1-PgN is not less than 3.

该装置由一支专门设计的测量探头3、两台高分辨率的CCD摄像机1、专用标定附件和一台装有配套软件系统的计算机4所组成。 The device consists of a specially designed measuring probe 3, two high-resolution CCD cameras 1, special calibration accessories and a computer 4 equipped with supporting software systems.

所述测量探头3是该装置的核心，测量探头3包括T形杆3-1、球形测量头3-2和一组标志点Pg1-PgN，T形杆3-1前端处装有球形测量头3-2，T形杆3-1要求与球形测量头3-2紧固在一起，不能有松动，其上贴有至少3个或者3个以上的标志点Pg1-PgN，标志点Pg1-PgN在T形杆3-1上成T型分布。为了增加系统的稳定性和准确性，同时考虑到T形杆3-1的尺寸，本本发明实施例设置5个标志点。 The measuring probe 3 is the core of the device, and the measuring probe 3 includes a T-shaped bar 3-1, a spherical measuring head 3-2 and a group of marking points Pg1-PgN, and a spherical measuring head is installed at the front end of the T-shaped bar 3-1 3-2. The T-shaped rod 3-1 is required to be fastened together with the spherical measuring head 3-2 without looseness, and there are at least 3 or more marking points Pg1-PgN and Pg1-PgN on it. Form a T-shaped distribution on the T-shaped bar 3-1. In order to increase the stability and accuracy of the system, and considering the size of the T-shaped bar 3-1, five marker points are set in the embodiment of the present invention.

所述两个CCD摄像机1固定在长方形金属板的两侧，两个CCD摄像机1的光心轴夹角在20至60度之间，CCD摄像机1与装有图像采集卡的计算机4连接。 The two CCD cameras 1 are fixed on both sides of the rectangular metal plate, the angle between the optical axes of the two CCD cameras 1 is between 20 and 60 degrees, and the CCD cameras 1 are connected with a computer 4 equipped with an image acquisition card.

测量前，需要对系统进行标定，其中包括两个摄像机1的标定，T形杆3-1上标志点的标定和球形测量头3-2中心位置的标定。 Before the measurement, the system needs to be calibrated, including the calibration of the two cameras 1, the calibration of the marking points on the T-shaped bar 3-1 and the calibration of the center position of the spherical measuring head 3-2.

CCD相机1的标定可以计算出在双目摄像机所定义的坐标系下的空间三维坐标，T形杆3-1上标志点Pg1-PgN的标定和球形测量头3-2中心位置的标定可以确定在测量探头坐标系下标志点空间三维坐标和球形测量头3-2中心点在测量探头3坐标系的坐标。 The calibration of the CCD camera 1 can calculate the spatial three-dimensional coordinates under the coordinate system defined by the binocular camera, the calibration of the marker points Pg1-PgN on the T-shaped bar 3-1 and the calibration of the center position of the spherical measuring head 3-2 can be determined The three-dimensional space coordinates of the marker point in the measuring probe coordinate system and the coordinates of the center point of the spherical measuring head 3-2 in the measuring probe 3 coordinate system.

有了上述的标定，就可以求出两个坐标系之间的3×3旋转矩阵R和3×1平移列向量T。 With the above calibration, the 3×3 rotation matrix R and the 3×1 translation column vector T between the two coordinate systems can be obtained.

建立了两个坐标系明确的转换关系后，根据事先标定出的球形测量头3-2中心点在测量探头坐标系的空间三维坐标，便可求解出球形测量头3-2在摄像机坐标系的三维坐标 After the clear conversion relationship between the two coordinate systems is established, according to the three-dimensional coordinates of the center point of the spherical measuring head 3-2 in the measuring probe coordinate system calibrated in advance, the position of the spherical measuring head 3-2 in the camera coordinate system can be solved. 3D coordinates

在测量时，两个CCD摄像机1是固定不动的，手持测量探头在不同的地方测量，测量探头测量的点的三维空间坐标都是在CCD摄像机坐标系下，从而实现了手持式测量探头测量系统的视觉三维坐标测量。 During the measurement, the two CCD cameras 1 are fixed, and the hand-held measuring probes are used to measure in different places. The three-dimensional space coordinates of the points measured by the measuring probes are all in the CCD camera coordinate system, thereby realizing the measurement of the hand-held measuring probes. Systematic visual three-dimensional coordinate measurement.

测量时，只需将球形测量头3-2接触测头接触物体上的待测点，CCD摄像机1摄取测量探头上的标志点Pg1-PgN的图像，图像采集卡采集CCD摄像机图像并将数据传送给计算机，计算机处理后便可计算出球形测量头3-2的三维坐标Pg（xg，yg，zg）。 When measuring, it is only necessary to touch the spherical measuring head 3-2 to the point to be measured on the object where the measuring head touches, and the CCD camera 1 captures the images of the marker points Pg1-PgN on the measuring probe, and the image acquisition card collects the images of the CCD camera and transmits the data The three-dimensional coordinates Pg (xg, yg, zg) of the spherical measuring head 3-2 can be calculated after computer processing.

该测量装置具备如下特征: The measuring device has the following characteristics:

1、功能强。 1. Strong function.

该系统结合了接触式测量和非接触式测量两种方法。能给出测量范围内空间任意测点的xyz三维坐标，是一个完整的三坐标测量系统，能完成单一几何要素的尺寸与形状的测量和关联要素的位置测量等多种功能。该系统可以有效地克服目前三坐标测量机柔性低、造价高以及非接触式扫描仪不能探测内表面的点及单独测量某个点的缺陷，且能够有效消除非接触式测量时的测量死角。 The system combines both contact and non-contact measurement methods. It can give the xyz three-dimensional coordinates of any measuring point in the space within the measurement range. It is a complete three-coordinate measurement system that can complete multiple functions such as the measurement of the size and shape of a single geometric element and the position measurement of associated elements. The system can effectively overcome the defects of low flexibility and high cost of the current three-coordinate measuring machine and the inability of non-contact scanners to detect points on the inner surface and measure a point alone, and can effectively eliminate the measurement dead angle during non-contact measurement.

2、便携性好，柔性高。 2. Good portability and high flexibility.

整个测量系统的质量在10-20kg左右，而不是如现在的三坐标测量机重数千公斤。且组建灵活、操作简单。因此，可把它携出室外或在某个大型工件的所在地进行现场测量。 The mass of the entire measuring system is about 10-20kg, instead of thousands of kilograms like the current coordinate measuring machine. And it is flexible to set up and easy to operate. Therefore, it can be taken outside or used for on-site measurements at the location of a large workpiece.

3、没有复杂的机械结构，造价低，同时，量程大，精度高。 3. No complex mechanical structure, low cost, large measuring range and high precision.

测量空间范围达到米级，测量精度达到0.2mm级。 The measurement space range reaches the meter level, and the measurement accuracy reaches the 0.2mm level.

本发明涉及的理论参看文献如下： The theory that the present invention relates to refers to document as follows:

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