A handheld binocular galvanometer scanning system and a calibration method thereof

Abstract

The application discloses a handheld binocular galvanometer scanning system and a calibration method thereof, and relates to the technical field of galvanometer scanning.The technical scheme points of the application comprise the following steps: acquiring calibration prior information, wherein the calibration prior information comprises camera internal parameters of a binocular imaging device and prior geometric data of a calibration target; controlling a galvanometer scanning component to scan at different scanning stages based on the calibration prior information, so that a laser beam forms multiple groups of laser stripes corresponding to the scanning stages on the calibration target; acquiring corresponding laser stripe images at each scanning stage through the binocular imaging device; processing the laser stripe images based on the camera internal parameters to extract pixel coordinates of pixel points on each laser stripe; and calibrating fixed geometric parameters that remain unchanged among multiple scanning stages based on geometric constraint equations and cross-stage consistency constraints, so that the global consistency and stability of the calibration result are improved.

Description

Technical Field

[0001] This invention relates to the field of galvanometer scanning technology, and more specifically, to a handheld binocular galvanometer scanning system and its calibration method. Background Technology

[0002] With the rapid development of industrial inspection, 3D reconstruction, robot vision, and precision measurement, higher demands are being placed on spatial 3D information acquisition in terms of measurement accuracy, acquisition efficiency, and flexibility of use. Laser scanning, as an active 3D measurement technology, has advantages such as high measurement accuracy and strong resistance to ambient light interference, and has been widely used in various engineering applications. Galvanometer scanning technology uses a high-speed oscillating mirror to precisely modulate the laser beam's emission direction, thus forming various spatial scanning modes such as line scanning, surface scanning, or cone scanning, offering significant advantages in improving scanning efficiency and expanding spatial coverage. Binocular imaging technology acquires target image information simultaneously through left and right cameras, providing more stable spatial constraints for the system and helping to improve the reliability of distance estimation and 3D reconstruction.

[0003] However, existing galvanometer scanning systems rely on multi-camera structures or complex system parameter calibration processes. The complex system structure and high calibration difficulty result in insufficient engineering adaptability, making it difficult to meet the requirements of handheld applications in terms of size, weight and ease of use. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a handheld binocular galvanometer scanning system and its calibration method.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A calibration method for a handheld binocular galvanometer scanning system includes the following steps:

[0007] Obtain calibration prior information, wherein the calibration prior information includes the camera intrinsic parameters of the binocular imaging device and the prior geometric data of the calibration target;

[0008] Based on the calibration prior information, the control galvanometer scanning component scans at different scanning stages, so that the laser beam forms multiple sets of laser stripes on the calibration target corresponding to the scanning stage.

[0009] At each scanning stage, the corresponding laser stripe image is acquired using a binocular imaging device;

[0010] Laser stripe images are processed based on camera intrinsic parameters to extract the pixel coordinates of each pixel on each laser stripe;

[0011] A set of geometric constraint equations for the laser plane parameters at each scanning stage is constructed based on pixel coordinates, camera intrinsic parameters, and prior geometric data of the calibration target.

[0012] Establish cross-stage consistency constraints for the geometric constraint equation set based on the motion characteristics of the galvanometer scanning component;

[0013] The fixed geometric parameters that remain unchanged across multiple scanning stages are calibrated based on the geometric constraint equations and cross-stage consistency constraints.

[0014] Preferably, a set of geometric constraint equations for the laser plane parameters at each scanning stage is constructed based on pixel coordinates, camera intrinsic parameters, and prior geometric data of the calibration target, specifically as follows:

[0015] Let the first The laser plane equation for each scanning stage is: ;in, Indicates the first Each scanning stage outputs a laser plane. This represents the projection component of the laser plane normal vector onto the X-axis. This represents the projection component of the laser plane normal vector onto the Y-axis. This represents the projection component of the laser plane normal vector onto the Z-axis. Represents the parameter of the constant term;

[0016] Based on the Pixel coordinates of each scan stage ( , and camera focal length Determine the corresponding spatial imaging ray vector ;

[0017] Let the spatial points of the laser stripe be... ,in, As a scale factor, Let be the spatial imaging ray vector corresponding to the j-th pixel in the i-th scanning stage;

[0018] Spatial points of laser stripes Substituting into the laser plane equation and combining it with the known spatial relationships between the calibrated target structural units, we can construct parameters about the laser plane. The geometric constraint equations.

[0019] Preferably, the calibration prior information further includes the static and dynamic parameters of the galvanometer scanning assembly;

[0020] The camera intrinsic parameters include focal length and relevant parameters of the imaging device.

[0021] Preferably, the prior geometric data includes known spatial spacing parameters between different structural units in the calibration plate.

[0022] Preferably, establishing cross-stage consistency constraints for the geometric constraint equation set based on the motion characteristics of the galvanometer scanning component specifically includes the following steps:

[0023] The spatial imaging ray distribution corresponding to the laser stripes in each scanning stage is obtained based on the pixel coordinates and camera intrinsic parameters.

[0024] The correlation between the changes in the laser beam propagation direction is obtained based on the rotational motion characteristics of the galvanometer scanning assembly;

[0025] Based on the correlation, the spatial imaging ray distribution of the previous scanning stage is used as a reference to correct the spatial imaging ray distribution of the subsequent scanning stage, and the correction relationship is obtained based on the corrected spatial imaging ray distribution and the reference.

[0026] Integrating the correction relation into the geometric constraint equations of each scanning stage yields the cross-stage consistency constraint of the geometric constraint equations.

[0027] A handheld binocular galvanometer scanning system includes a control system configured to perform a calibration method for the handheld binocular galvanometer scanning system, and further includes a scanner housing, a laser generator, a galvanometer scanning assembly, and a binocular imaging device.

[0028] The laser generator is installed inside the scanner housing and is used to generate a laser beam.

[0029] The galvanometer scanning assembly is installed inside the scanner housing. The galvanometer scanning assembly is used to receive and reflect the laser beam generated by the laser generator, and modulate the emission direction of the laser beam by driving the reflector to swing, so as to form a scanning trajectory in the target space.

[0030] The binocular imaging device is installed inside the scanner housing. The binocular imaging device includes a left camera and a right camera. The binocular imaging device is used to simultaneously acquire images of the target object from different perspectives.

[0031] The control system is electrically connected to the laser generator, the galvanometer scanning assembly, and the binocular imaging device. The control system is used to coordinate and control laser emission, galvanometer scanning, and image acquisition, and to process image data to obtain three-dimensional information of the target object.

[0032] Preferably, the control system is configured to control the galvanometer scanning assembly to form the laser beam into at least one projection mode among point laser, single-line laser, multi-line parallel laser, or intersecting laser lines.

[0033] Preferably, the front end face of the scanner housing is provided with a laser projection window, a left camera window, a right camera window, and an LED lighting array surrounding the laser projection window.

[0034] Preferably, the scanner also includes an attitude sensor, which is disposed inside the scanner housing and electrically connected to the control system. The attitude sensor is used to acquire attitude change information during handheld movement.

[0035] Preferably, the galvanometer scanning assembly includes a first galvanometer motor, a first reflector connected to the first galvanometer motor, a second galvanometer motor, and a second reflector connected to the second galvanometer motor;

[0036] The laser beam is reflected sequentially by the first and second reflectors. The control system drives the first and second galvanometer motors to coordinate the swinging of the first and second reflectors to form the emitted laser beam.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] This invention introduces prior calibration information to provide reliable initial constraints for the calibration process, reducing parameter solution errors without initial conditions and significantly improving the accuracy of laser stripe extraction and geometric constraint construction. Through multi-stage galvanometer scanning and binocular synchronous image acquisition, multiple sets of laser stripe data from different locations can be acquired, avoiding the problem of insufficient data in a single stage leading to limited constraints. A single-stage geometric constraint equation set is constructed based on the prior geometric data of the calibration target within the camera, directly linking two-dimensional pixel coordinates with three-dimensional laser plane parameters to achieve accurate solution of single-stage laser plane parameters, ensuring accurate and reliable local geometric relationships in each scanning stage. Cross-stage consistency constraints are established based on the galvanometer motion characteristics, globally associating geometric constraints from different scanning stages to effectively correct motion deviations and optical errors between stages, improving the global consistency and stability of the calibration results. By simultaneously solving the geometric constraint equation set and cross-stage consistency constraints, joint optimization calibration is performed on fixed geometric parameters that remain unchanged across multiple stages, enabling the solution of installation errors between the camera and galvanometer, key parameters of the system's geometric reference, and improving measurement accuracy and robustness. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of a handheld binocular galvanometer scanning system provided in an embodiment of the present invention;

[0040] Figure 2 A schematic diagram of the light source and imaging system structure of a handheld binocular galvanometer scanner is provided for embodiments of the present invention;

[0041] Figure 3 A schematic diagram of a variable structure laser projection method in a handheld binocular galvanometer scanning system is provided for embodiments of the present invention;

[0042] Figure 4 This is a schematic diagram illustrating the calibration principle of an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the calibration process according to an embodiment of the present invention. Detailed Implementation

[0044] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0045] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0046] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0047] Reference Figures 1-5 As shown.

[0048] The embodiments further illustrate the handheld binocular galvanometer scanning system and its calibration method proposed in this invention.

[0049] A calibration method for a handheld binocular galvanometer scanning system includes the following steps:

[0050] Acquire calibration prior information, which includes the camera intrinsic parameters of the binocular imaging device and the prior geometric data of the calibration target;

[0051] The calibration prior information also includes the static and dynamic parameters of the galvanometer scanning assembly;

[0052] Camera intrinsic parameters include focal length and related parameters of the imaging device.

[0053] Prior geometric data includes known spatial spacing parameters between different structural units in the calibration plate.

[0054] Camera intrinsic parameters include focal length and related parameters of the imaging device. These parameters determine the mapping relationship between pixel coordinates and spatial imaging rays during the imaging process. They are the basis for deriving the spatial ray distribution from the pixel coordinates of the laser stripe image. The calibration prior information includes the prior geometric data of the calibration target. The specific indicators of the prior geometric data are the known spatial spacing parameters between different structural units in the plate. This kind of known spatial spacing information is the key benchmark for constructing the geometric constraint equation set. It can provide spatial constraints for solving the position of the laser stripe spatial points and ensure that the derived laser plane parameters conform to the real spatial geometric relationship.

[0055] The prior information for calibration includes the static and dynamic parameters of the galvanometer scanning assembly. The static parameters mainly reflect the basic geometric characteristics of the galvanometer scanning assembly in its fixed installation state, such as the initial installation position and angle of the reflector. The dynamic parameters reflect the motion characteristics of the reflector during the scanning process, such as the correspondence between the rotation angle and the control signal. Both types of parameters jointly support the process of establishing cross-stage consistency constraints based on the motion characteristics of the galvanometer. This provides a basis for the correlation correction of the laser beam propagation direction between different scanning stages, ensuring that the geometric constraints of each stage can form an overall optimization condition. This provides comprehensive and reliable prior support for the joint calibration of fixed geometric parameters, ensuring the accuracy and stability of the entire calibration process.

[0056] Based on the calibration prior information, the control galvanometer scanning component scans at different scanning stages, so that the laser beam forms multiple sets of laser stripes on the calibration target corresponding to the scanning stage.

[0057] The galvanometer scanning assembly is subjected to phased scanning control operations based on calibration prior information. This prior information includes binocular camera intrinsic parameters, target geometry data, and the static and dynamic parameters of the galvanometer. This information provides the initial geometric and kinematic basis for galvanometer scanning angle control and path planning. Based on the galvanometer's dynamic parameters, the scanning assembly adjusts the mirror's swing angle according to a preset angle sequence at different scanning stages, thereby changing the laser beam's emission direction. Under the modulation of the galvanometer, the laser beam projects a series of continuous laser stripes onto the target surface. Different scanning stages correspond to different galvanometer control parameters; therefore, the multiple sets of projected laser stripes form different spatial distributions on the target. These laser stripes, distributed at different locations, serve as the key data foundation for constructing the geometric constraint equation set and establishing cross-stage consistency constraints.

[0058] At each scanning stage, the corresponding laser stripe image is acquired using a binocular imaging device;

[0059] Once the galvanometer scanning assembly completes the laser beam modulation for the current stage, projecting the laser stripes onto the calibration target, the corresponding laser stripe image is immediately acquired by the binocular imaging device. The two imaging units of the binocular imaging device capture images of the laser stripes on the calibration target from different fixed perspectives. This dual-view synchronous acquisition method simultaneously obtains the two-dimensional projection information of the same laser stripe in the coordinate systems of the two cameras, providing fundamental constraints for three-dimensional spatial reconstruction and controlling the timing of image acquisition and galvanometer scanning. This ensures that the acquired image completely corresponds to the laser emission state of the current scanning stage, avoiding mismatches between stripe positions and galvanometer control parameters due to time deviations. The laser stripes in each scanning stage have different spatial positions on the calibration target, and the corresponding acquired images also exhibit different pixel distribution characteristics. These images are completely saved as a direct data source for extracting laser stripe pixel coordinates and constructing geometric constraint equations for each stage. They also provide a reliable image foundation for establishing cross-stage consistency constraints between different scanning stages.

[0060] Laser stripe images are processed based on camera intrinsic parameters to extract the pixel coordinates of each pixel on each laser stripe;

[0061] Camera intrinsic parameters include focal length and imaging device-related parameters. These parameters define the geometric mapping relationship of camera imaging and are the basis for image correction and feature extraction. The camera intrinsic parameters are used to correct distortion in the acquired laser stripe image, eliminating pixel position deviations caused by optical distortion of the imaging device, making the laser stripe projection in the image more consistent with the ideal pinhole imaging model. Image enhancement processing highlights the laser stripe region, identifies the centerline trajectory of the laser stripes, and finally outputs the pixel coordinates.

[0062] Based on pixel coordinates, camera intrinsic parameters, and prior geometric data of the calibration target, a set of geometric constraint equations is constructed regarding the laser plane parameters at each scanning stage, specifically:

[0063] Let the first The laser plane equation for each scanning stage is: ;in, Indicates the first Each scanning stage outputs a laser plane. This represents the projection component of the laser plane normal vector onto the X-axis. This represents the projection component of the laser plane normal vector onto the Y-axis. This represents the projection component of the laser plane normal vector onto the Z-axis. Represents the parameter of the constant term;

[0064] Based on the Pixel coordinates of each scan stage ( , and camera focal length Determine the corresponding spatial imaging ray vector ;

[0065] Let the spatial points of the laser stripe be... ,in, As a scale factor, Let be the spatial imaging ray vector corresponding to the j-th pixel in the i-th scanning stage;

[0066] Spatial points of laser stripes Substituting into the laser plane equation and combining it with the known spatial relationships between the calibrated target structural units, we can construct parameters about the laser plane. The geometric constraint equations.

[0067] Define the output laser plane for each scanning stage, and let the first... The laser plane equation for each scanning stage is: This includes the projection components of the plane normal vector onto the three coordinate axes and constant parameters. These four parameters together determine the plane position and orientation of the laser beam in three-dimensional space during this stage. Based on the first... The coordinates of the laser stripe pixels and the camera focal length in each scanning stage are used to calculate the spatial imaging ray vector corresponding to each pixel. This vector reflects the three-dimensional spatial direction from the camera optical center through the pixel. The spatial point of the laser stripe is represented as the product of the spatial imaging ray vector and a scale factor, where the scale factor represents the length of the ray vector from the camera optical center to the actual laser stripe spatial point, thus establishing a mapping relationship between two-dimensional pixels and three-dimensional spatial points. Substituting the spatial point of the laser stripe into the laser plane equation and combining it with the known spatial spacing parameters between the calibrated target structural units, a corresponding equation is established for each laser stripe spatial point. Multiple equations are combined to form a complete set of geometric constraint equations, which can be solved to obtain the... The four parameters of the laser plane in each scanning stage provide a single-stage geometric parameter basis for establishing cross-stage consistency constraints.

[0068] The cross-stage consistency constraints of the geometric constraint equation set based on the motion characteristics of the galvanometer scanning component are established, specifically including the following steps:

[0069] The spatial imaging ray distribution corresponding to the laser stripes in each scanning stage is obtained based on the pixel coordinates and camera intrinsic parameters.

[0070] The correlation between the changes in the laser beam propagation direction is obtained based on the rotational motion characteristics of the galvanometer scanning assembly;

[0071] Based on the correlation, the spatial imaging ray distribution of the previous scanning stage is used as a reference to correct the spatial imaging ray distribution of the subsequent scanning stage, and the correction relationship is obtained based on the corrected spatial imaging ray distribution and the reference.

[0072] By incorporating the correction relationship into the geometric constraint equations of each scanning stage, we obtain the cross-stage consistency constraint of the geometric constraint equations.

[0073] The spatial imaging ray distribution corresponding to the laser stripes in each scanning stage is obtained based on the pixel coordinates and camera intrinsic parameters. The camera intrinsic parameters provide the basis for mapping from two-dimensional pixel coordinates to three-dimensional spatial rays. Each pixel in the laser stripe corresponds to a spatial imaging ray originating from the camera's optical center and passing through that pixel. The set of rays corresponding to all pixels constitutes the spatial imaging ray distribution for that stage. The correlation between the changes in the laser beam propagation direction is obtained based on the rotational motion characteristics of the galvanometer scanning assembly. A definite kinematic mapping relationship exists between the swing angle of the mirror in the galvanometer scanning assembly and the laser beam emission direction. This kinematic mapping relationship is jointly determined by the static installation parameters and dynamic motion parameters of the galvanometer, reflecting the changing law of the laser beam propagation direction between different scanning stages, providing a theoretical basis for cross-stage ray correction. Subsequently, based on the above correlation, the system uses the spatial imaging ray distribution of the previous scanning stage as a benchmark to correct the spatial imaging ray distribution of the subsequent scanning stage. Because the motion of the galvanometer is continuous and regular, the light distribution in the later stage should satisfy a specific kinematic correlation with the light distribution in the previous stage. Correction can eliminate inconsistencies caused by imaging errors or motion deviations. Then, based on the correspondence between the corrected spatial imaging light distribution and the reference distribution, a cross-stage correction relationship is obtained. This correction relationship is integrated into the geometric constraint equations of each scanning stage, constructing a cross-stage consistency constraint for the geometric constraint equations. This allows the solution of laser plane parameters in different scanning stages to be interconnected through the motion characteristics of the galvanometer, ensuring that the parameters in all stages satisfy unified physical and geometric laws, thus improving the accuracy and robustness of the calibration results.

[0074] The fixed geometric parameters that remain unchanged across multiple scanning stages are calibrated based on the geometric constraint equations and cross-stage consistency constraints.

[0075] The geometric constraint equations provide local constraints on the laser plane parameters and spatial imaging rays for each scanning stage, ensuring accurate mapping between pixel coordinates and 3D spatial points within a single stage. Cross-stage consistency constraints, based on the motion characteristics of the galvanometer scanning assembly, correlate the ray distribution of different scanning stages with the laser plane parameters, ensuring that parameters across all stages satisfy uniform physical motion laws and eliminating error accumulation between stages. Integrating these two types of constraints, a global optimization model is constructed to solve for fixed geometric parameters that remain unchanged across multiple scanning stages, including the installation position relationship between the camera and the galvanometer, the static installation error of the galvanometer, and the overall geometric reference parameters. These fixed parameters determine the 3D measurement accuracy of the entire scanning system. By jointly solving for multi-stage constraints, the impact of single-stage errors can be effectively reduced, improving the robustness and accuracy of parameter calibration and providing a reliable system geometric foundation for 3D scanning measurement.

[0076] Figure 3 This is a schematic diagram of the variable structure laser projection method in the handheld binocular galvanometer scanning system of the present invention, intuitively demonstrating diverse laser projection forms. The control system, by driving the coordinated oscillation of the two reflecting mirrors of the galvanometer scanning component, can flexibly modulate the emission direction and spatial distribution of the laser beam, generating various projection modes such as point lasers, single-line lasers, multi-line parallel lasers, and intersecting laser lines. Different projection modes can adapt to different 3D scanning scenarios, meeting both high-precision single-point measurement requirements and enabling large-area, rapid line scanning, balancing scanning efficiency and measurement accuracy, highlighting the flexibility and engineering adaptability of the system's laser projection structure.

[0077] Figure 4 This document presents the core logic and physical implementation process of system calibration. It includes key elements such as a calibration plate (with multi-level stepped surfaces providing prior geometric data), galvanometers, reflectors, a binocular CCD imaging camera, and the laser propagation path. It also labels the core parameters of the laser plane equations for multiple scanning stages (Stage 1, Stage 2 to Stage N). During calibration, the galvanometers project laser beams in stages, forming multiple sets of laser stripes on the stepped surfaces of the calibration plate. The binocular camera simultaneously acquires stripe images from different perspectives. Combining the prior geometric data from the camera and the calibration plate, a set of geometric constraint equations for the laser plane parameters at each stage is constructed. Based on the motion characteristics of the galvanometers, cross-stage consistency constraints are established. Finally, the system's fixed geometric parameters are calibrated by simultaneously solving these constraints. This clearly demonstrates the entire calibration process from laser projection and image acquisition to geometric constraint construction and parameter solving.

[0078] A handheld binocular galvanometer scanning system includes a control system 5, which is configured to perform a calibration method for a handheld binocular galvanometer scanning system, and also includes a scanner housing 1, a laser generator 8, a galvanometer scanning assembly, and a binocular imaging device.

[0079] The laser generator 8 is installed inside the scanner housing 1, and the laser generator 8 is used to generate a laser beam;

[0080] The front face of the scanner housing 1 is provided with a laser projection window 15, a left camera window 13, a right camera window 16, and an LED lighting array 14 surrounding the laser projection window.

[0081] The laser generator 8 generates the laser beam required for scanning. This laser beam is the basic light source for the galvanometer scanning component to modulate the emission direction and form a scanning trajectory on the target surface, providing active structured light signals for the 3D scanning process and supporting image acquisition and 3D reconstruction. The front face of the scanner housing 1 serves as the working surface for the system to interact with the external target, integrating multiple key windows and lighting components. Among them, the laser projection window 15 is the channel for the laser beam to be projected onto the external target after being emitted from the internal galvanometer scanning component, ensuring that the laser beam is emitted without obstruction and protecting the internal optical components from external contamination and damage. The left camera window 13 and the right camera window 16 provide shooting channels for the two cameras of the binocular imaging device, enabling the cameras to simultaneously acquire laser stripe images of the target from different perspectives, providing binocular visual data support for 3D reconstruction. The LED lighting array 14 surrounding the laser projection window provides uniform auxiliary lighting for the target scene, which can improve the imaging brightness of the target surface in complex environments such as low light or high reflectivity, enhance the contrast between the laser stripes and the background, and ensure that the binocular imaging device can clearly capture the laser stripe image, providing a reliable image data foundation for image processing and geometric constraint construction.

[0082] The galvanometer scanning assembly is installed inside the scanner housing 1. The galvanometer scanning assembly is used to receive and reflect the laser beam generated by the laser generator 8, and modulate the emission direction of the laser beam by driving the mirror to swing, so as to form a scanning trajectory in the target space.

[0083] The galvanometer scanning assembly receives and reflects the laser beam generated by the laser generator 8, guiding the initial laser beam into the subsequent optical path. The galvanometer scanning assembly modulates the emission direction of the laser beam by driving a reflector to swing. Driven by a control signal, the reflector reciprocates, changing the reflection angle of the laser beam and causing its emission direction to change according to a preset path. The modulated laser beam forms a continuous and controllable scanning trajectory in the target space, providing laser stripes for the binocular imaging device to acquire. This supports image acquisition, geometric constraint construction, and 3D reconstruction processes, enabling rapid and high-precision scanning coverage of the target surface.

[0084] The binocular imaging device is installed inside the scanner housing 1. The binocular imaging device includes a left camera 2 and a right camera 6. The binocular imaging device is used to simultaneously acquire images of the scanning trajectory on the target object 12 from different perspectives.

[0085] Left camera 2 and right camera 6 are mounted with a fixed baseline spacing and viewing angle to form the spatial geometry required for binocular vision measurement. After the galvanometer scanning assembly projects the laser beam onto the surface of target object 12 to form a scanning trajectory, the binocular imaging device simultaneously acquires laser stripe images of target object 12 from different viewing angles. Left camera 2 and right camera 6 respectively capture the scanning trajectory at the same moment, obtaining the two-dimensional projection information of the same laser stripe in the coordinate systems of the two cameras. This dual-view synchronous acquisition method can provide key parallax data for three-dimensional reconstruction, enabling the calculation of three-dimensional point cloud data on the surface of target object 12.

[0086] The control system 5 is electrically connected to the laser generator 8, the galvanometer scanning assembly and the binocular imaging device respectively. The control system 5 is used to coordinate and control laser emission, galvanometer scanning and image acquisition, and process image data to obtain the three-dimensional information of the target object 12.

[0087] The control system 5 coordinates and controls the laser emission, sending start and modulation signals to the laser generator 8 to control the timing and intensity of the laser beam emission, ensuring that the laser beam, modulated by the galvanometer scanning assembly, can be projected onto the surface of the target object 12 along a preset path. The control system 5 sends drive signals to the galvanometer scanning assembly, controlling the swing angle and speed of the reflector to form a trajectory that meets the scanning requirements, achieving efficient coverage of the target object 12's surface. The control system 5 triggers the binocular imaging device to acquire images, ensuring that the left camera 2 and the right camera 6 complete image acquisition from different perspectives at the same time, guaranteeing the temporal alignment of the scanning trajectory and image data. The control system 5 receives the image data transmitted back from the binocular imaging device, extracts the pixel coordinates of the laser stripes, combines them with prior calibration information within the cameras to construct and solve a set of geometric constraint equations, ultimately obtaining the three-dimensional point cloud information of the target object 12's surface, completing the data loop of the entire scanning process.

[0088] The control system 5 is configured to control the galvanometer scanning assembly to form the laser beam into at least one projection mode among point laser, single-line laser, multi-line parallel laser, or intersecting laser lines.

[0089] It also includes a posture sensor 3, which is disposed inside the scanner housing 1 and electrically connected to the control system 5. The posture sensor 3 is used to acquire posture change information during handheld movement.

[0090] The attitude sensor 3 is electrically connected to the control system 5 to achieve real-time transmission and interaction of attitude data. The control system 5 synchronously receives the motion data collected by the sensor, providing temporally aligned pose information support for 3D reconstruction. The attitude sensor 3 is used to acquire attitude change information during handheld movement, collect motion parameters such as angular velocity and acceleration in real time, and calculate the real-time attitude and displacement changes of the scanner. This facilitates the correction of viewpoint deviations and pose errors caused by handheld movement, unifies point cloud data from different scanning stages into the same coordinate system, and improves the accuracy of 3D reconstruction and the coherence of data stitching.

[0091] The galvanometer scanning assembly includes a first galvanometer motor 4, a first reflector 7 connected to the first galvanometer motor 4, a second galvanometer motor 9, and a second reflector 10 connected to the second galvanometer motor 9;

[0092] The first galvanometer motor 4 is directly connected to the first reflector 7 and can drive the first reflector 7 to swing around a specific axis according to the control signal, so as to realize the angular deflection of the laser beam in the dimension; the second galvanometer motor 9 is directly connected to the second reflector 10 and drives the second reflector 10 to swing around another axis, so as to realize the angular deflection of the laser beam in the vertical direction. The two work together to complete the two-dimensional control of the laser beam emission direction.

[0093] The laser beam is reflected sequentially by the first reflector 7 and the second reflector 10. The control system 5 drives the first galvanometer motor 4 and the second galvanometer motor 9 to coordinate the swinging of the first reflector 7 and the second reflector 10 to form the emitted laser 11.

[0094] The laser beam generated by the laser generator is incident on the first reflecting mirror 7. After being reflected by the first reflecting mirror 7, its propagation direction changes once. It is then incident on the second reflecting mirror 10, and after being reflected again, it is emitted from the laser projection window as the outgoing laser 11. The control system 5 sends coordinated drive signals to the first galvanometer motor 4 and the second galvanometer motor 9 to control the swing angle and timing of the two reflecting mirrors. By changing the combination of the angles of the two reflections, the direction of the outgoing laser 11 is continuously changed, enabling it to form a point, line, or surface scanning trajectory in the target space, providing the acquired laser stripe signal for the binocular imaging device.

[0095] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0096] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A calibration method for a handheld binocular galvanometer scanning system, characterized in that, Includes the following steps: Obtain calibration prior information, wherein the calibration prior information includes the camera intrinsic parameters of the binocular imaging device and the prior geometric data of the calibration target; Based on the calibration prior information, the control galvanometer scanning component scans at different scanning stages, so that the laser beam forms multiple sets of laser stripes on the calibration target corresponding to the scanning stage. At each scanning stage, the corresponding laser stripe image is acquired using a binocular imaging device; Laser stripe images are processed based on camera intrinsic parameters to extract the pixel coordinates of each pixel on each laser stripe; A set of geometric constraint equations for the laser plane parameters at each scanning stage is constructed based on pixel coordinates, camera intrinsic parameters, and prior geometric data of the calibration target. The cross-stage consistency constraints of the geometric constraint equation set based on the motion characteristics of the galvanometer scanning component are established, specifically including the following steps: The spatial imaging ray distribution corresponding to the laser stripes in each scanning stage is obtained based on the pixel coordinates and camera intrinsic parameters. The correlation between the changes in the laser beam propagation direction is obtained based on the rotational motion characteristics of the galvanometer scanning assembly; Based on the correlation, the spatial imaging ray distribution of the previous scanning stage is used as a reference to correct the spatial imaging ray distribution of the subsequent scanning stage, and the correction relationship is obtained based on the corrected spatial imaging ray distribution and the reference. By incorporating the correction relationship into the geometric constraint equations of each scanning stage, we obtain the cross-stage consistency constraint of the geometric constraint equations. The fixed geometric parameters that remain unchanged across multiple scanning stages are calibrated based on the geometric constraint equations and cross-stage consistency constraints.

2. The calibration method for a handheld binocular galvanometer scanning system according to claim 1, characterized in that, Based on pixel coordinates, camera intrinsic parameters, and prior geometric data of the calibration target, a set of geometric constraint equations is constructed regarding the laser plane parameters at each scanning stage, specifically: Let the first The laser plane equation for each scanning stage is: ;in, Indicates the first Each scanning stage outputs a laser plane. This represents the projection component of the laser plane normal vector onto the X-axis. This represents the projection component of the laser plane normal vector onto the Y-axis. This represents the projection component of the laser plane normal vector onto the Z-axis. Represents the parameter of the constant term; Based on the Pixel coordinates of each scan stage ( , and camera focal length Determine the corresponding spatial imaging ray vector ; Let the spatial points of the laser stripe be... ,in, As a scale factor, Let be the spatial imaging ray vector corresponding to the j-th pixel in the i-th scanning stage; Spatial points of laser stripes Substituting into the laser plane equation and combining it with the known spatial relationships between the calibrated target structural units, we can construct parameters about the laser plane. The geometric constraint equations.

3. The calibration method for a handheld binocular galvanometer scanning system according to claim 1, characterized in that, The calibration prior information also includes the static and dynamic parameters of the galvanometer scanning assembly; Camera intrinsic parameters include focal length and related parameters of the imaging device.

4. The calibration method for a handheld binocular galvanometer scanning system according to claim 1, characterized in that, The prior geometric data includes known spatial spacing parameters between different structural units in the calibration plate.

5. A handheld binocular galvanometer scanning system, comprising a control system (5), said control system (5) being configured to perform a calibration method for a handheld binocular galvanometer scanning system according to any one of claims 1 to 4, characterized in that, It also includes a scanner housing (1), a laser generator (8), a galvanometer scanning assembly, and a binocular imaging device; The laser generator (8) is installed inside the scanner housing (1) and is used to generate a laser beam; The galvanometer scanning assembly is installed inside the scanner housing (1). The galvanometer scanning assembly is used to receive and reflect the laser beam generated by the laser generator (8), and modulate the emission direction of the laser beam by driving the reflector to swing, so as to form a scanning trajectory in the target space. The binocular imaging device is installed inside the scanner housing (1). The binocular imaging device includes a left camera (2) and a right camera (6). The binocular imaging device is used to simultaneously acquire images of the scanning trajectory on the target object (12) from different perspectives. The control system (5) is electrically connected to the laser generator (8), the galvanometer scanning assembly and the binocular imaging device respectively. The control system (5) is used to coordinate and control laser emission, galvanometer scanning and image acquisition, and process image data to obtain the three-dimensional information of the target object (12).

6. A handheld binocular galvanometer scanning system according to claim 5, characterized in that, The control system (5) is configured to control the galvanometer scanning assembly to form the laser beam into at least one projection mode among point laser, single-line laser, multi-line parallel laser or cross laser line.

7. A handheld binocular galvanometer scanning system according to claim 6, characterized in that, The front end of the scanner housing (1) is provided with a laser projection window (15), a left camera window (13), a right camera window (16), and an LED lighting array (14) surrounding the laser projection window.

8. A handheld binocular galvanometer scanning system according to claim 6, characterized in that, It also includes a posture sensor (3), which is disposed inside the scanner housing (1) and electrically connected to the control system (5). The posture sensor (3) is used to acquire posture change information during handheld movement.

9. A handheld binocular galvanometer scanning system according to claim 6, characterized in that, The galvanometer scanning assembly includes a first galvanometer motor (4), a first reflector (7) connected to the first galvanometer motor (4), a second galvanometer motor (9), and a second reflector (10) connected to the second galvanometer motor (9). The laser beam is reflected sequentially by the first reflector (7) and the second reflector (10). The control system (5) drives the first galvanometer motor (4) and the second galvanometer motor (9) to coordinate the swing of the first reflector (7) and the second reflector (10) to form the emitted laser (11).

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