CN-116592766-B - Precise three-dimensional measurement method and device based on fusion of laser and monocular vision

Abstract

The invention discloses a precise three-dimensional measurement method and device based on fusion of laser and monocular vision. The measuring method comprises the steps of calibrating the relative positions of a monocular camera and a quick reflection mirror deflection center, collecting depth information by a laser ranging module, determining pixel coordinates of a laser ranging point by the monocular camera, combining the depth information and the pixel coordinates to obtain three-dimensional information of the laser ranging point under a camera coordinate system, judging whether the quick reflection mirror scanning process is finished, if not, continuing to deflect the quick reflection mirror, repeating the measuring process, and if so, outputting a three-dimensional point cloud. The method of the invention utilizes the camera to obtain the coordinate information of the laser ranging point, combines the advantages of the camera and the laser measurement, realizes the precise three-dimensional measurement which reaches the pixel level precision in the two-dimensional plane direction and is equivalent to the laser ranging precision in the depth direction, has lower implementation cost and is beneficial to technical popularization and application.

Inventors

• LIU BO
• YI HAO

Assignees

• 中国科学院光电技术研究所

Dates

Publication Date

20260512

Application Date

20230705

Claims (3)

1. 1. The precise three-dimensional measurement method based on fusion of laser and monocular vision is characterized by comprising the following steps of: S1, carrying out joint calibration on deflection centers of a monocular camera and a quick reflection mirror to obtain calibration parameters including a camera internal reference matrix K and position information of the deflection center of the quick reflection mirror under a camera coordinate system ); S2, the laser ranging module emits visible laser and is driven by a fast reflecting mirror to realize beam deflection; s3, the monocular camera collects pixel information of the laser ranging points emitted by the laser ranging module ) Simultaneously recording depth information measured by a corresponding laser ranging module ; S4, obtaining position information of the deflection center of the quick reflection mirror under the camera coordinate system according to the camera internal reference matrix K obtained in the S1 ) Pixel information obtained in S3 ) And depth information Calculating to obtain three-dimensional coordinate information (x, y, z) of the ranging points of the laser ranging module under a camera coordinate system; S5, judging whether the scanning process of the quick reflection mirror is finished, if not, deflecting the quick reflection mirror, repeating S2, S3 and S4, and if so, outputting three-dimensional coordinate information of all ranging points, namely three-dimensional point cloud; The step S1 specifically comprises the following steps: s11, performing monocular camera calibration by using a chess board pattern calibration plate through a Zhang Zhengyou calibration method to obtain a camera internal reference matrix K; S12, deflecting the laser beam by using a quick reflection mirror, deflecting the laser ranging points to corner points of different checkerboards, and respectively recording depth information of three laser spots, namely a spot a, a spot b and a spot c 、 And And pixel information [ ] )、( ) And% ) Because the checkerboard spacing is fixed, the spacing between the light spots a and b can be obtained Spacing of spots b and c And the spacing of spots a and c Thereby, the position information of the deflection center of the quick reflection mirror under the camera coordinate system ) The calculation is as follows: Wherein, the A real number to be calculated which is more than 0; The step S4 specifically comprises the following steps: S41, calculating three-dimensional coordinate information (x, y, z) of a ranging point of the laser ranging module, wherein the method comprises the following steps: wherein t is the real number of the distance measurement points obtained by the camera, K is the internal reference matrix, u and v are the pixel information of the distance measurement points obtained by the camera, For the depth information measured by the laser ranging module, Is the position information of the deflection center of the quick reflection mirror under the camera coordinate system.
2. 2. A measuring device used in the precision three-dimensional measuring method according to claim 1, comprising: The laser ranging module is used for measuring depth information and emitting visible light spots; a fast mirror for beam deflection; the monocular camera is used for acquiring spot pixel information of the laser measuring point; And the data processing unit is used for image processing, three-dimensional information acquisition and three-dimensional point cloud output.
3. 3. The measuring device of claim 2, wherein the monocular camera, the quick mirror and the laser ranging module are connected with the data processing unit through data lines.

Description

Precise three-dimensional measurement method and device based on fusion of laser and monocular vision Technical Field The invention relates to the field of three-dimensional measurement, in particular to a precise three-dimensional measurement method and device based on fusion of laser and monocular vision. Background With the rapid development of sensor technology and computer vision technology, many tasks such as automatic driving, robots and remote sensing measurement have high requirements on a precise three-dimensional measurement method. The existing mainstream three-dimensional measurement method is divided into passive three-dimensional measurement based on a camera and active three-dimensional measurement based on a laser radar, and a monocular camera can measure and obtain accurate azimuth angle and pitching angle information of a target, but cannot recover scale information in real 3D motion from image data, and cannot acquire reliable high-precision three-dimensional measurement information. The laser radar can obtain high-precision distance information of a target, but the two-dimensional resolution of the plane of the laser radar is low, and for the main-stream scanning laser radar, the three-dimensional measurement precision of the laser radar is seriously dependent on an angle measurement device. The single sensor is difficult to meet the requirement of high-precision three-dimensional measurement, and the existing method adopts combination of measurement results of multiple sensors to improve measurement precision when in measurement, namely, the laser radar and the camera are used for measurement respectively, and then a proper algorithm is used for carrying out fusion calculation on each scheme and finally obtaining the measurement result, so that the method has the defects in terms of calculation resource consumption and measurement precision. Disclosure of Invention The invention aims to solve the defects of the existing laser and monocular vision fusion measurement technology and provides a precise three-dimensional measurement method and device based on laser and monocular vision fusion. According to the invention, the camera is utilized to obtain the angle information of the laser measurement point, so that the scanning type laser radar is effectively prevented from depending on a high-precision angle measurement device, the pixel-level precision is achieved in the two-dimensional plane direction, and the precise three-dimensional measurement equivalent to the laser ranging precision in the depth direction is realized. The invention is realized in the following way: first, the invention provides a precise three-dimensional measurement method based on fusion of laser and monocular vision, which comprises the following steps: s1, carrying out joint calibration on deflection centers of a monocular camera and a quick reflection mirror to obtain calibration parameters including a camera internal reference matrix K and position information (x f,yf,zf) of the deflection center of the quick reflection mirror under a camera coordinate system; s2, the laser ranging module emits visible laser and is driven by a fast reflecting mirror to realize beam deflection; s3, the camera collects pixel information of the laser ranging points emitted by the laser ranging module, and simultaneously records depth information obtained by measuring the corresponding laser ranging module; s4, calculating to obtain three-dimensional coordinate information of the measuring point of the laser ranging module under the camera coordinate system according to the camera internal reference matrix obtained in the S1, the position information of the deflection center of the quick reflection mirror under the camera coordinate system, and the pixel information and the depth information obtained in the S3; And S5, judging whether the scanning process of the quick reflection mirror is finished, if not, deflecting the quick reflection mirror, repeating S2, S3 and S4, and if so, outputting three-dimensional coordinate information of all the ranging points, namely three-dimensional point clouds. Further, the step S1 specifically includes: s11, performing monocular camera calibration by using a chess board pattern calibration plate through a Zhang Zhengyou calibration method to obtain a camera internal reference matrix K; S12, deflecting the laser beam by using a quick reflection mirror, deflecting the laser ranging points to corner points of different checkered, and respectively recording depth information (d a、db and d c) and pixel information (u a,va、ub,vb and u c,vc) of three laser spots (spot a, spot b and spot c). Because the checkerboard spacing is fixed, the distance L ab between the light spot a and the light spot b, the distance L bc between the light spot b and the light spot c, and the distance L ac between the light spot a and the light spot c can be obtained, and therefore, the position information (x f,yf,zf) of the