CN-121977469-A - Ultra-large on-orbit structure pose three-dimensional measurement method based on binocular vision

CN121977469ACN 121977469 ACN121977469 ACN 121977469ACN-121977469-A

Abstract

The invention relates to a binocular vision-based ultra-large on-orbit structure pose three-dimensional measurement method which comprises the steps of building two groups of vision measurement terminals, building a global measurement terminal, building a reference coordinate system, obtaining a three-dimensional coordinate of a mark point and a three-dimensional coordinate of a target ball in a coordinate system W2, respectively calculating the position of the mark point on a target tool by each group of vision measurement terminals, converting the coordinate systems of the two groups of vision measurement terminals into the coordinate system W2 according to the known position of the mark point, calibrating the coordinate system W2 and the reference coordinate system, obtaining target point coordinates by the two groups of vision measurement terminals and converting the target point coordinates into the coordinate system W2, measuring the vibration center of the target ball by using a laser tracker, obtaining the three-dimensional coordinate of the target ball in the reference coordinate system, calculating the conversion relation between the coordinate system W2 and the reference coordinate system, and further obtaining the target point coordinates in the reference coordinate system. The invention overcomes the limitation of the traditional method in three-dimensional pose measurement in a large-scale and complex environment.

Inventors

Hong Youxie
YANG FENGLONG
JIA MINTAO
WANG BIN
REN HAILONG
YU WANGZHU
LIU HUIYANG
LI HONGWEI

Assignees

北京卫星制造厂有限公司

Dates

Publication Date: 20260505
Application Date: 20251223

Claims (8)

1. The utility model provides a three-dimensional measuring method of super large on-orbit structure pose based on binocular vision, is the truss structure that is including a plurality of truss modules to the on-orbit structure of being measured, its characterized in that includes following steps: S1, building and calibrating two groups of vision measurement terminals symmetrically arranged on two sides of a truss structure, wherein each group of vision measurement terminals comprises binocular cameras and a light source positioned between the binocular cameras, the two groups of vision measurement terminals are connected to the same supporting structure which can move along the length direction of the truss structure and can transmit vibration, and the internal and external parameters of the two groups of binocular cameras are calibrated; S2, building a global measurement terminal and establishing a reference coordinate system, wherein the global measurement terminal comprises a laser tracker with a fixed position, a plurality of target seats arranged on a supporting structure and a plurality of target balls arranged on the target seats; S3, setting a calibration target tool with the same spatial position as the truss structure, and performing photogrammetry calibration by using the calibration target tool to obtain three-dimensional coordinates of a plurality of mark points on the calibration target tool under a local coordinate system W2 and three-dimensional coordinates of a target ball arranged on a target seat; s4, each group of vision measurement terminals respectively calculates the positions of marking points on the calibration target tool, and the coordinate systems of the two groups of vision measurement terminals are converted into a local coordinate system W2 by using a least square algorithm according to the positions of the marking points obtained in the step S3; s5, acquiring three-dimensional coordinates of a target point on the truss module by using two groups of vision measurement terminals; s6, converting the coordinates of the target points of the targets acquired by the two groups of vision measurement terminals into a local coordinate system W2 by utilizing the coordinate conversion relation in the step S4; S7, measuring the vibration center of the target ball by using a laser tracker in a vibration environment, carrying out average calculation on the vibration center of the target ball obtained in the measurement period to obtain a target ball three-dimensional coordinate under a reference coordinate system, and completing conversion from the local coordinate system W2 to the reference coordinate system according to the target ball three-dimensional coordinate under the local coordinate system W2 obtained by photogrammetry calibration and the target ball three-dimensional coordinate under the reference coordinate system; And S8, moving the vision measurement terminal to the next truss module, and repeating the steps S5-S7 until the three-dimensional coordinates of the target points of all the truss modules in the reference coordinate system are obtained.
2. The binocular vision-based three-dimensional measuring method for pose of oversized on-orbit structure, as set forth in claim 1, wherein at least 4 target points are respectively arranged on two sides of a single truss module.
3. The binocular vision-based three-dimensional measuring method for the pose of the ultra-large on-orbit structure is characterized in that the calibrating target tool adopts a cubic structure which is the same as that of a truss module, the space position of the calibrating target tool is coincident with that of the truss module, the two opposite surfaces of the calibrating target tool are provided with stable plane structures, and marking points are adhered to the surfaces of the calibrating target tool.
4. The binocular vision-based three-dimensional measuring method for the pose of the oversized on-orbit structure, which is disclosed in claim 1, is characterized in that the specific method in the step S4 is as follows: the marker points obtained by photogrammetry in step S3 are based on three-dimensional coordinates in the local coordinate system W2, Each group of vision measurement terminals respectively calculates and records three-dimensional coordinates of mark points on the calibration target tool through a sensor and a built-in algorithm, and the coordinates are based on a local coordinate system established by each vision measurement terminal; for each group of vision measurement terminals, identifying and matching the mark points at the known positions in the step S3 with the mark points measured by the terminals, and ensuring the one-to-one correspondence of the points in the two groups of data based on the coding information of the mark points; establishing a mathematical model for converting the local coordinate system of each vision measurement terminal into a local coordinate system W2 by using a least square algorithm, wherein the mathematical model comprises the steps of determining a rotation matrix R1 and a translation vector T1, so that the square sum of the distance between corresponding point coordinates Qi in the vision measurement terminal after the conversion of the rotation matrix R1 and the translation vector T1 and the mark point coordinates Pi in the step S3 is minimum; Using the resulting rotation matrix R1 and translation vector T1, all landmark coordinates Qi in each set of vision measurement terminals are transformed from the terminal local coordinate system to the local coordinate system W2.
5. The binocular vision-based three-dimensional measurement method for pose of ultra-large on-orbit structure according to claim 1, wherein the conversion from the local coordinate system W2 to the reference coordinate system in step S7 is as follows: measuring the vibration center of each target ball by using a laser tracker, and carrying out average calculation on the vibration center of the target ball obtained in the measurement period to obtain the three-dimensional coordinate of the target ball under a reference coordinate system W1; Recognizing and matching the three-dimensional coordinates of the target ball at the known position under the local coordinate system W2 with the three-dimensional coordinates of the target ball under the reference coordinate system W1 obtained by the laser tracker, and ensuring the one-to-one correspondence of points in the two groups of data based on the target ball coding information; A mathematical model for converting the local coordinate system W2 into the reference coordinate system W1 is established by using a least square algorithm, wherein the mathematical model comprises the steps of determining a rotation matrix R2 and a translation vector T2, so that the square sum of the distance between the corresponding target sphere coordinate Fi under the local coordinate system W2 and the target sphere coordinate Gi under the reference coordinate system W1 after the transformation of the rotation matrix R2 and the translation vector T2 is minimum; Using the resulting rotation matrix R2 and translation vector T2, all target spherical coordinates Fi in the local coordinate system W2 are converted from the local coordinate system W2 to the reference coordinate system W1.
6. The binocular vision-based three-dimensional measuring method for the pose of the ultra-large on-orbit structure according to claim 1, wherein in the step S7, the measurement of the vibration center of the target ball needs to ensure that the dynamic acquisition time of each target ball is longer than one vibration period.
7. The binocular vision-based three-dimensional measuring method for the pose of the ultra-large on-orbit structure, which is disclosed in claim 1, is characterized in that the target points are concentric circle paper targets and are arranged at each corner point of the truss module.
8. The binocular vision-based ultra-large on-orbit structure pose three-dimensional measurement method is characterized in that the target points are glass microsphere reflecting target points, and the inner circle surface is made of reflecting materials.

Description

Ultra-large on-orbit structure pose three-dimensional measurement method based on binocular vision Technical Field The invention belongs to the technical field of pose three-dimensional measurement, and relates to a binocular vision-based ultra-large on-orbit structure pose three-dimensional measurement method which is suitable for spaceflight, aviation or other occasions requiring accurate measurement of key parameters in the assembly process of a large structure. Background Three-dimensional measurement technology is an indispensable important tool in the fields of modern industry, scientific research and engineering, and is centered on realizing accurate measurement of the shape, size and position of an object through various sensors and algorithms. With the rapid development of computer vision, optics and mechanical automation technology, three-dimensional measurement technology is continuously advanced, and is widely applied to the fields of industrial detection, robot navigation, medical image analysis, cultural heritage protection and the like. In three-dimensional measurement, common methods include structured light scanning, laser scanning, stereoscopic vision, time of flight (ToF), and the like. These techniques acquire geometric information of the object surface in different ways, thereby constructing a three-dimensional model thereof. However, these conventional methods still have limitations in facing large-scale, complex surfaces or dynamic environments. Therefore, how to improve the efficiency and applicability of three-dimensional measurement while ensuring high accuracy is an important direction of current research. Disclosure of Invention The invention solves the technical problems of overcoming the defects of the prior art, providing a binocular vision-based ultra-large on-orbit structure pose three-dimensional measurement method, overcoming the limitation of the traditional method in a large-scale and complex environment, providing data support for on-orbit assembly adjustment, and providing a high-efficiency and reliable solution for special scenes such as on-orbit measurement and the like. The technical problem is solved by a binocular vision-based three-dimensional measuring method for the pose of an oversized on-orbit structure, wherein the measured on-orbit structure is a truss structure comprising a plurality of truss modules, and the method comprises the following steps of: S1, building and calibrating two groups of vision measurement terminals symmetrically arranged on two sides of a truss structure, wherein each group of vision measurement terminals comprises binocular cameras and a light source positioned between the binocular cameras, the two groups of vision measurement terminals are connected to the same supporting structure which can move along the length direction of the truss structure and can transmit vibration, and the internal and external parameters of the two groups of binocular cameras are calibrated; S2, building a global measurement terminal and establishing a reference coordinate system, wherein the global measurement terminal comprises a laser tracker with a fixed position, a plurality of target seats arranged on a supporting structure and a plurality of target balls arranged on the target seats; S3, setting a calibration target tool with the same spatial position as the truss structure, and performing photogrammetry calibration by using the calibration target tool to obtain three-dimensional coordinates of a plurality of mark points on the calibration target tool under a local coordinate system W2 and three-dimensional coordinates of a target ball arranged on a target seat; s4, each group of vision measurement terminals respectively calculates the positions of marking points on the calibration target tool, and the coordinate systems of the two groups of vision measurement terminals are converted into a local coordinate system W2 by using a least square algorithm according to the positions of the marking points obtained in the step S3; s5, acquiring three-dimensional coordinates of a target point on the truss module by using two groups of vision measurement terminals; s6, converting the coordinates of the target points of the targets acquired by the two groups of vision measurement terminals into a local coordinate system W2 by utilizing the coordinate conversion relation in the step S4; S7, measuring the vibration center of the target ball by using a laser tracker in a vibration environment, carrying out average calculation on the vibration center of the target ball obtained in the measurement period to obtain a target ball three-dimensional coordinate under a reference coordinate system, and completing conversion from the local coordinate system W2 to the reference coordinate system according to the target ball three-dimensional coordinate under the local coordinate system W2 obtained by photogrammetry calibration and the target ball three-dimensional coordina