CN-121742039-B - Laser galvanometer automatic correction method and system based on computer vision and coaxial reference light

CN121742039BCN 121742039 BCN121742039 BCN 121742039BCN-121742039-B

Abstract

The invention discloses a laser galvanometer automatic correction method and system based on computer vision and coaxial reference light, the proposal maps the deflection state of the galvanometer to a calibration plane by introducing the coaxial reference light source of the galvanometer, and then based on the light spot and the position formed by the computer vision acquisition reference light source on the calibration plane, further calculating the light spot deviation, and automatically correcting the coordinate transformation parameters of the galvanometer. The scheme provided by the invention can automatically detect and correct the vibration mirror deviation, effectively improve the consistency and the positioning precision, and simultaneously improve the efficiency of vibration mirror correction.

Inventors

ZHAO ZHIWU
WANG HONGKUN
GUO LIANG
XU JIANWEI
Zhai Jiacan

Assignees

蔚蓝引擎(上海)科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260227

Claims (10)

1. A laser galvanometer automatic correction system based on computer vision and on-axis reference light, the system comprising: the calibration plane is matched with the combined bracket to form a calibration environment; The combined support is used for bearing the vibrating mirror assembly to be corrected and the camera shooting assembly, and the camera shooting assembly can acquire light spots generated on a calibration plane by the correction light ray indicator coaxially arranged with the vibrating mirror assembly to be corrected; The correction light ray indicator is used for being coaxially installed with a vibrating mirror in the vibrating mirror assembly to be corrected and can generate correction light rays along the coaxial direction of the vibrating mirror to face a calibration plane so as to form light spots on the calibration plane; The camera shooting assembly is arranged on the combined bracket and can acquire a calibration plane and a facula image formed on the calibration plane; the control assembly is arranged to control and connect the camera shooting assembly, the correction light indicator and the vibrating mirror assembly to be corrected, the vibrating mirror correction module is configured in the control assembly, the vibrating mirror correction module can control the camera shooting assembly to correct distortion parameters, obtain the mapping relation from pixel coordinates to physical calibration plane coordinates, control the vibrating mirror in the vibrating mirror assembly to be corrected to drive the coaxially installed correction light indicator to deflect, control the correction light indicator to work on a calibration plane to produce light spots, control the camera shooting assembly to collect calibration plane images with the light spots after the vibrating mirror deflects in place, calculate the deviation between actual light spot coordinates and target positions based on the collected images and the mapping relation between the pixel coordinates and the physical calibration plane coordinates, and control the completion correction of the vibrating mirror in the vibrating mirror assembly accordingly.
2. The automated laser galvanometer calibration system of claim 1, wherein the calibration plane is comprised of a standard reflector or a diffuse reflective target.
3. The automatic laser galvanometer correction system according to claim 1, wherein the control assembly comprises a control host and a galvanometer control board, wherein the galvanometer correction module is operated in the control host and is in control connection with the galvanometer control board, and the galvanometer control board is connected with the galvanometer assembly to be corrected.
4. The automatic laser galvanometer correction system of claim 1, wherein the galvanometer correction module comprises a calibration sub-module, a zero reference correction sub-module, a scaling parameter correction sub-module, a distortion parameter correction sub-module, The calibration submodule is used for controlling the camera shooting assembly to calibrate relative to a calibration plane and establishing a mapping relation between pixels and plane coordinates; the zero reference correction sub-module is arranged to control and adjust zero reference parameters of the vibrating mirror assembly to be corrected to finish zero reference correction based on the mapping relation established by the standard sub-module; The scaling parameter correction sub-module is arranged to control and adjust the scaling parameter of the vibrating mirror assembly to be corrected to finish scaling parameter correction after the zero reference correction sub-module finishes correction; The distortion parameter correction sub-module is configured to complete distortion parameter correction based on the zero reference parameter and the scaling parameter that have been corrected after the scaling parameter correction sub-module completes correction.
5. A method for automatically correcting a laser galvanometer based on computer vision and coaxial reference light, characterized in that it is based on the laser galvanometer automatic correction system according to any one of claims 1-4, comprising: S1, calibrating a camera shooting assembly relative to a calibration plane to obtain a mapping relation from pixel coordinates to physical calibration plane coordinates; S2, controlling a vibrating mirror in a vibrating mirror assembly to be corrected to drive a coaxially installed correction light indicator to deflect, and controlling a correction light indicator to work on a light spot generated on a calibration plane; s3, after the vibrating mirror deflects in place, acquiring a calibration plane image with the light spot by the camera shooting assembly, and calculating the deviation between the actual light spot coordinate and the target position based on the acquired image and the mapping relation between the pixel coordinate and the physical calibration plane coordinate; And S4, controlling the vibrating mirror in the vibrating mirror assembly to be corrected to drive the coaxially installed correction light indicator to deflect according to the deviation forming adjustment instruction, and repeating the steps S2-S3 until the deviation between the actual light spot coordinates and the target position is smaller than a preset threshold value, thereby completing the correction of the vibrating mirror in the vibrating mirror assembly.
6. The method according to claim 5, wherein the step S1 is performed to obtain the distortion parameter correction of the image capturing component and obtain the mapping relationship from the pixel coordinates to the physical plane coordinates when the image capturing component is calibrated.
7. The method for automatically calibrating a laser galvanometer according to claim 6, wherein in the step S3, the spot center pixel coordinate is calculated based on the collected calibration plane image, then the spot center pixel coordinate is mapped to the physical coordinate under the actual galvanometer coordinate system, and finally the deviation between the actual spot coordinate and the target position is calculated.
8. The automatic calibration method of laser galvanometer according to claim 7, wherein the step S4 includes a zero reference calibration procedure, in which the zero reference parameter is adjusted according to the calculated deviation between the actual spot coordinates and the target position by a set minimum step adjustment amount, so as to form an adjustment command to control the galvanometer in the galvanometer assembly to be calibrated to drive the coaxially installed calibration light indicator to deflect, and repeat the detection and the calibration until the error is lower than a threshold value.
9. The automatic calibration method of laser galvanometer according to claim 8, wherein the step S4 further comprises a scaling parameter calibration procedure, wherein the scaling parameter calibration procedure selects a plurality of test point coordinates on a calibration plane based on the zero reference parameter corrected in the zero reference calibration procedure, and controls the galvanometer in the galvanometer assembly to be calibrated to sequentially point to the selected test point coordinates, and simultaneously generates a light spot on the calibration plane by a coaxial calibration light indicator, and calculates the deviation between the actual light spot coordinates and the target position; and adjusting the scaling parameters in the scaling part according to the set minimum stepping adjustment quantity, forming an adjustment instruction according to the scaling parameters to control the vibrating mirror in the vibrating mirror assembly to be corrected to drive the coaxially installed correction light indicator to deflect, and repeatedly detecting and correcting until the errors of all points are lower than a threshold value.
10. The method according to claim 9, wherein the step S4 further comprises a distortion parameter correction step of selecting 4 corner points on the calibration plane based on the zero reference parameter corrected in the zero reference correction step and the scaling parameter corrected in the scaling parameter correction step, Controlling the vibrating mirrors in the vibrating mirror assembly to be corrected to sequentially point to the selected angular point coordinates, and simultaneously generating light spots on a calibration plane by a coaxial correction light ray indicator; and calculating the deviation between the actual spot coordinates and the target position for each corner point, adjusting the distortion parameters in the scaling part according to the set minimum stepping adjustment amount, and repeatedly detecting and correcting the distortion parameters, and iteratively optimizing the distortion parameters until the error of each corner point is lower than a threshold value.

Description

Laser galvanometer automatic correction method and system based on computer vision and coaxial reference light Technical Field The invention belongs to the technical field of laser control and computer vision calibration, and particularly relates to an automatic correction scheme of a laser galvanometer. Background In laser systems, a galvanometer (Galvo Scanner) is used to precisely control the deflection of a laser beam to achieve positioning and scanning of the laser on a target plane. However, when existing galvanometer products are shipped, the internal X, Y deflection motor is not usually provided with a strict limit or mechanical clamping system, so that certain installation deviation and zero drift exist among different galvanometers. The deviation directly affects the accuracy of the galvanometer coordinate conversion formula, so that an error exists between the theoretical pointing direction and the actual light spot falling point. For example, when the coordinates of the target point are (0, 0), the actual spot falling on the reference plane 80cm from the galvanometer may be off-center, resulting in a centimeter-level error. Correction for this deviation problem is usually performed empirically by a person. The manual correction mode relies on empirical adjustment, and is complex in process, low in efficiency and poor in repeatability. With the trend of high precision of laser application, the manual detection and correction-based mode cannot meet the requirements. Therefore, there is a need in the art for an automated vision correction scheme capable of automatically detecting and correcting galvanometer aberrations to improve consistency and positioning accuracy. Disclosure of Invention Aiming at the problems caused by manual detection and calibration of the vibration mirror deviation in the existing laser system, the invention aims to provide an automatic correction scheme of the laser vibration mirror based on computer vision and coaxial reference light, which uses a red light indicator as a coaxial reference light source, collects the position of red light on a calibration plane through a camera, calculates the light spot deviation and automatically aims at the problems caused by manual detection and calibration of the vibration mirror deviation in the existing laser system. To achieve the above object, in one aspect, the present invention provides a laser galvanometer automatic correction system based on computer vision and coaxial reference light, the system comprising: the calibration plane is matched with the combined bracket to form a calibration environment; The combined support is used for bearing the vibrating mirror assembly to be corrected and the camera shooting assembly, and the camera shooting assembly can acquire light spots generated on a calibration plane by the correction light ray indicator coaxially arranged with the vibrating mirror assembly to be corrected; The correction light ray indicator is used for being coaxially installed with a vibrating mirror in the vibrating mirror assembly to be corrected and can generate correction light rays along the coaxial direction of the vibrating mirror to face a calibration plane so as to form light spots on the calibration plane; The camera shooting assembly is arranged on the combined bracket and can acquire a calibration plane and a facula image formed on the calibration plane; the control assembly is arranged to control and connect the camera shooting assembly, the correction light indicator and the vibrating mirror assembly to be corrected, the vibrating mirror correction module is configured in the control assembly, the vibrating mirror correction module can control the camera shooting assembly to correct distortion parameters, obtain the mapping relation from pixel coordinates to physical calibration plane coordinates, control the vibrating mirror in the vibrating mirror assembly to be corrected to drive the coaxially installed correction light indicator to deflect, control the correction light indicator to work on a calibration plane to produce light spots, control the camera shooting assembly to collect calibration plane images with the light spots after the vibrating mirror deflects in place, calculate the deviation between actual light spot coordinates and target positions based on the collected images and the mapping relation between the pixel coordinates and the physical calibration plane coordinates, and control the completion correction of the vibrating mirror in the vibrating mirror assembly accordingly. Further, the calibration plane is formed by a standard reflecting plate or a diffuse reflecting target surface. Further, the control assembly comprises a control host and a vibrating mirror control board card, a vibrating mirror correction module is operated in the control host and is in control connection with the vibrating mirror control board card, and the vibrating mirror control board card is connected with the v