A calibration method for laser galvanometer scanning system based on binocular camera

Abstract

The present invention discloses a calibration method for a laser galvanometer scanning system based on a binocular camera, which belongs to the field of galvanometer calibration. The method can calibrate the relative position relationship between the galvanometer and the binocular camera and the geometric model parameters of the galvanometer itself, and can be used to project the laser to a specified three-dimensional target position. The main steps are: constructing a calibration model, collecting calibration data, processing the calibration data to obtain the corresponding relationship between the outgoing laser beam and the control signal of the galvanometer, and solving the parameters of the calibration model step by step. Compared with the methods published in the existing literature, the innovation of the present invention lies in the established galvanometer geometric model, which does not limit the angle of the incident laser beam and the position relationship between the two reflectors, while reducing the number of parameters of the calibration model and improving the calibration accuracy of the galvanometer. This makes the method of the present invention have extremely high application value in the fields of laser marking, 3D printing, laser projection and laser processing.

Description

Technical Field

[0001] The present invention relates to the technical field of laser galvanometer calibration, and in particular to a calibration method of a laser galvanometer scanning system based on a binocular camera. Background Art

[0002] Laser galvanometers are used to control the direction of laser emission. How to calibrate them efficiently and accurately has always been the core issue of laser galvanometer-related applications. Compared with early laser plane marking, the application of laser galvanometers has expanded from small-scale two-dimensional plane scanning to large-scale three-dimensional space scanning. In order to meet the requirement of high-precision three-dimensional space scanning of laser galvanometers, the laser galvanometer scanning system must be calibrated so that the outgoing laser beam can accurately reach any given position in space by controlling the deflection of the galvanometer.

[0003] In some calibration methods, the following ideal conditions need to be assumed: when the galvanometer system is in the initial state, ① the incident angle of the incident laser beam on the first reflector is 45°; ② the angle between the two reflector axes is 90°; ③ the incident laser beam must hit the center of the first reflector axis. However, in the actual manufacturing and assembly process, it is difficult to strictly meet such ideal conditions.

[0004] Other calibration methods are based on computer neural network algorithms, which use a large number of neural network parameters to fit the corresponding relationship between the digital signal of the galvanometer and the orientation of the outgoing light beam. This is also a relatively effective method, but this method cannot meet the needs of high-precision applications. Summary of the invention

[0005] In view of the problems in the prior art that the calibration process of the laser galvanometer scanning system has strict condition requirements or low calibration accuracy, the purpose of the present invention is to provide a calibration method for the laser galvanometer scanning system based on a binocular camera.

[0006] To achieve the above object, the technical solution of the present invention is:

[0007] In a first aspect, the present invention provides a calibration method for a binocular camera-based laser galvanometer scanning system, the system comprising an X-mirror, a Y-mirror, a rotating device and a control device, the rotation axis positions of the X-mirror and the Y-mirror are fixed, the rotating device is used to drive the X-mirror and the Y-mirror to rotate, the control device is used to drive the rotating device through a control signal, the control signal comprises an x ​​signal and a y signal respectively used to control the rotation of the X-mirror and the Y-mirror, the method is used to calibrate the relationship between the control signal and the azimuth of an outgoing laser beam emitted by the system, the method comprising the following steps:

[0008] S1. Constructing a calibration model representing the relationship between the control signal and the orientation of the outgoing laser beam emitted by the system, wherein the calibration model comprises:

[0009] α=a1x+a2x 2 +a3x 3 ,

[0010] β=b1y+b2y 2 +b3y 3 ,

[0011] R x =matrix(cosα+u sinα),

[0012] R y =matrix(cosβ+v sinβ),

[0013] l=R y R x m,

[0014] Q=R y (R x (PX)+XY)+Y;

[0015] Wherein, X and Y represent the three-dimensional coordinate points on the rotation axis of the X mirror and the Y mirror, respectively; u and v represent the unit direction vectors of the rotation axis of the X mirror and the Y mirror, respectively; P and m represent the three-dimensional coordinate points and the unit direction vector on the outgoing laser beam in the initial state, respectively; α represents the rotation angle of the X mirror relative to the initial state under the x signal; β represents the rotation angle of the Y mirror relative to the initial state under the y signal; R x , R y They respectively represent the rotation of the light by the X mirror and the Y mirror, l represents the direction of the outgoing laser beam, Q represents the point coordinate position of the outgoing laser beam, and the initial state is the state where both the x signal and the y signal are zero;

[0016] S2, setting a curtain on one side of the laser beam emission direction of the system, and making the distance of the curtain relative to the system variable;

[0017] S3, inputting the same set of control signals to the system respectively when the screen is at at least two different distances from the system, thereby obtaining a set of laser spots at each position of the screen;

[0018] S4, determining the coordinates of each group of laser spots by a binocular camera to obtain multiple groups of spot coordinates;

[0019] S5, extracting the spot coordinates corresponding to the same control signal, fitting the spatial straight line using the principal component analysis method, and obtaining the corresponding relationship between the control signal and the direction l of the outgoing laser beam;

[0020] S6. Extracting the unit direction vector m and the three-dimensional coordinate point P of the outgoing laser beam in the initial state according to the corresponding relationship;

[0021] S7. Using the corresponding relationship, and according to the formula in S1, calculate and obtain X, Y, u, v, a1, a2, a3, b1, b2, and b3, so as to determine the calibration model and realize the calibration of the laser galvanometer scanning system.

[0022] Furthermore, the calibration method further includes a parameter optimization step, and the parameter optimization step includes:

[0023] S8, taking the objective function as the sum of squares of the difference between the direction of the outgoing laser beam calculated by the calibration model and the direction of the outgoing laser beam actually measured, and optimizing u, v, and m by a nonlinear optimization algorithm;

[0024] S9, taking the objective function as the sum of squares of the difference between the point coordinate position of the outgoing laser beam calculated by the calibration model and the point coordinate position of the outgoing laser beam actually measured, and optimizing X, Y, and P by a nonlinear optimization algorithm;

[0025] S10, taking the objective function as the sum of squares of the differences between the point coordinate position of the outgoing laser beam calculated by the calibration model and the point coordinate position of the outgoing laser beam actually measured, and optimizing a1, a2, a3, b1, b2, b3 by a nonlinear optimization algorithm.

[0026] Preferably, the same set of control signals is obtained by:

[0027] The y signal is kept unchanged, and the x signal is changed to obtain a plurality of first control signals; the x signal is kept unchanged, and the y signal is changed to obtain a plurality of second control signals.

[0028] Preferably, in S7, the parameters of the calibration model are calculated by the following steps:

[0029] Substituting the plurality of the first control signals into the model, a1, a2, a3 and u are calculated;

[0030] After the plurality of the second control signals are introduced into the model, b1, b2, b3 and v are obtained by calculation.

[0031] Preferably, X, Y, u, and v are all fixed parameters that do not change with changes in the control signal and are obtained through prior measurement and calculation.

[0032] Preferably, u is calculated by the following formula:

[0033] in, is the angle between u and the z-axis, and θ is the angle between the projection of u on the XY plane and the x-axis.

[0034] Preferably, X and Y represent the two points on the rotation axis of the X mirror and the rotation axis of the Y mirror which are closest to each other, and the distance between the two is d, then there is a formula Y=X+d(u×v).

[0035] Preferably, in S9, d is further taken as an optimization parameter, so that Y is calculated by X and d.

[0036] In a second aspect, the present invention further provides a computer-readable storage medium storing a computer program, wherein the computer program executes the method described above when executed by a processor.

[0037] By adopting the above technical scheme, the beneficial effect of the present invention is that: starting from the deflection angle of the galvanometer mirror affected by the control signal, the influence of the deflection angle of each galvanometer mirror and the outgoing laser beam is analyzed, so as to establish a calibration model. The calibration model is not only unrelated to the incident laser beam, but also does not require the incident orientation of the laser beam and the lens of the galvanometer mirror to be in an ideal state, thereby reducing the model parameters and making the calculation process simpler. In addition, the calibration model has a high correlation with the geometric model of the galvanometer scanning system, which can effectively improve the calibration accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of the laser galvanometer scanning system in the present invention;

[0039] Figure 2 This is a flow chart of a method according to Embodiment 1 of the present invention;

[0040] Figure 3 It is a schematic diagram of the screen at different distances in the present invention;

[0041] Figure 4 This is a flow chart of the method of embodiment 5 of the present invention.

[0042] In the figure: 1-X mirror, 2-Y mirror, 3-motor, 4-screen. DETAILED DESCRIPTION

[0043] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] It should be noted that, in the description of the present invention, the directions or positional relationships indicated by the terms "up", "down", "left", "right", "front", "back", etc. are descriptions of the structure of the present invention based on the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0045] The "first" and "second" in this technical solution are only used to distinguish the names of the same or similar structures, or corresponding structures with similar functions, and are not an arrangement of the importance of these structures, nor do they have a ranking, comparison of size, or other meanings.

[0046] In addition, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be a connection between the two structures. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood based on the overall idea of ​​the present invention and the specific context of the present solution.

[0047] Embodiment 1

[0048] A calibration method for a laser galvanometer scanning system based on a binocular camera is applied to Figure 1 The laser galvanometer scanning system shown in the figure includes an X-mirror 1, a Y-mirror 2, a rotating device and a control device. Among them, the rotation axes of the X-mirror 1 and the Y-mirror 2 are perpendicular to each other, and the rotating device is used to drive the X-mirror 1 and the Y-mirror 2 to rotate. For example, the rotating device is configured as two motors 3, and the two motors 3 are respectively used to drive the X-mirror 1 and the Y-mirror 2 to rotate. The control device controls the two motors 3 to rotate through control signals, thereby driving the X-mirror and the Y-mirror to rotate. Specifically, the control signal includes an x ​​signal and a y signal respectively used to control the rotation of the X-mirror 1 and the Y-mirror 2. Under the control of the control signal, the two motors 3 respectively drive the X-mirror 1 and the Y-mirror 2 to rotate, thereby deflecting the incident laser beam and outputting an outgoing laser beam with a certain orientation. The calibration method provided in this embodiment is used to calibrate the relationship between the control signal and the orientation of the outgoing laser beam emitted by the system, such as Figure 2 As shown, the calibration method includes the following steps:

[0049] S1. Constructing a calibration model representing the relationship between the control signal and the orientation of the outgoing laser beam emitted by the system, the calibration model comprising:

[0050] α=a1x+a2x 2 +a3x 3 (Formula 1);

[0051] β=b1y+b2y 2 +b3y 3 (Formula 2);

[0052] R x =matrix(cosα+u sinα) (Formula 3);

[0053] R y =matrix(cosβ+v sinβ) (Formula 4);

[0054] l=R y R x m (Formula 5);

[0055] Q=R y (R x (PX)+XY)+Y (Formula 6);

[0056] Wherein, X and Y represent the three-dimensional coordinate points on the rotation axis of the X mirror and the Y mirror, respectively; u and v represent the unit direction vectors of the rotation axis of the X mirror and the Y mirror, respectively; P and m represent the three-dimensional coordinate points and the unit direction vector on the outgoing laser beam in the initial state, respectively; α represents the rotation angle of the X mirror relative to the initial state under the x signal; β represents the rotation angle of the Y mirror relative to the initial state under the y signal; R x , R y They respectively represent the rotation of the X mirror and the Y mirror on the light, l represents the direction of the outgoing laser beam, Q represents the point coordinate position of the outgoing laser beam, and the initial state is a state where both the x signal and the y signal are zero.

[0057] In the above formula, (Formula 1) represents the deflection angle of the x signal to the X mirror. When x is 0, α is also 0, that is, the X mirror is not deflected. The same is true for (Formula 2). According to the principle of light reflection, when the X mirror deflects an angle of α in the initial state, the incident laser beam is deflected by an angle of 2α. Similarly, when the Y mirror deflects an angle of β in the initial state, the incident laser beam is deflected by an angle of 2β. Therefore, the rotation matrix R generated by the quaternion can be x , R y To represent the rotation of the X mirror and Y mirror to the incident laser beam, we have (Equation 3)-(Equation 5). Correspondingly, the position of the outgoing laser beam can be expressed by the above parameters, as shown in (Equation 6).

[0058] S2. A curtain 4 is arranged on one side of the laser beam emission direction of the system, and the distance of the curtain 4 relative to the system is variable.

[0059] The curtain 4 is used to block the outgoing laser beam to form a light spot. In this embodiment, a black curtain is preferred. The curtain 4 can be arranged in a hanging manner through a bracket. By adjusting the position of the bracket, the distance of the curtain 4 relative to the system can be changed, that is, the position of the curtain 4 relative to the system can be changed. According to the principle that two points determine a straight line, there are at least two positions of the curtain 4 relative to the system. At each position, the distance between the curtain 4 and the system is different. For example, in this embodiment, the curtain 4 is configured to have three positions with different distances relative to the system.

[0060] S3. When the screen 4 is at at least two different distances from the system, the same set of control signals is input to the system respectively, so as to obtain a set of laser spots at each position of the screen 4.

[0061] In this embodiment, a group of laser spots obtained at each position of the curtain 4 is called a frame of data. Figure 3 As shown, there are three frames of data.

[0062] S4. Determine the coordinates of each group of laser spots through a binocular camera to obtain multiple groups of spot coordinates.

[0063] Each laser spot on the screen 4 can determine its coordinate position through the binocular camera. For multiple laser spots in each frame of data, each corresponds to a set of spot coordinates with a determined coordinate position, and multiple frames of data correspond to multiple sets of spot coordinates. It can be understood that all the above-mentioned spot coordinates are measured in the same binocular camera coordinate system, that is, the position of the binocular camera relative to the system is kept unchanged.

[0064] S5. Extract the spot coordinates corresponding to the same control signal, fit the space straight line using the principal component analysis method, and obtain the corresponding relationship between the control signal and the direction l of the outgoing laser beam.

[0065] For the same control signal, since the curtain 4 has three distance positions, there will be three light spot coordinates, and the line connecting the three light spot coordinates is considered to coincide with the corresponding outgoing laser beam; similarly, multiple control signals correspond to multiple outgoing laser beams; after calculation, the corresponding relationship between the control signal and the direction l of the outgoing laser beam can be preliminarily obtained.

[0066] S6. According to the corresponding relationship, extract the unit direction vector m and the three-dimensional coordinate point P of the outgoing laser beam in the initial state.

[0067] The initial state refers to the situation where both the x signal and the y signal in the control signal are 0. Substituting both the x signal and the y signal into the corresponding relationship determined in S5, the direction of the outgoing laser beam in the initial state can be calculated, thereby obtaining the unit direction vector m of the outgoing laser beam in the initial state. Combined with the distance position of the curtain 4, a three-dimensional coordinate point P on the outgoing laser beam can be determined.

[0068] S7. Select multiple control signals and their corresponding spot coordinates, obtain the directions l of multiple outgoing laser beams by calculating the spot coordinates, and then substitute the calculated values ​​into the formula in S1 to obtain X, Y, u, v, a1, a2, a3, b1, b2, and b3, thereby determining the calibration model and realizing the calibration of the laser galvanometer scanning system.

[0069] It can be understood that the direction l of a series of outgoing laser beams can be calculated through the spot coordinates measured in S4. At the same time, when P and m are known, the relevant control signals are brought into (Formula 1)-(Formula 5), ​​and X, Y, u, v, a1, a2, a3, b1, b2, b3 can be obtained by solving multivariate equations, thereby determining the calibration model and realizing the calibration of the laser galvanometer scanning system. After the calibration is completed, the required control signal can be directly calculated through the calibration model according to the required orientation of the outgoing laser beam, and then the required outgoing laser beam can be emitted after being executed by the system.

[0070] In this embodiment, by setting the initial state, the constant terms of (Equation 1) and (Equation 2) are omitted, further simplifying the complexity of the calibration model. In addition, the calibration model provided in this embodiment is not associated with the incident laser beam, nor does it contain parameters related to the initial arrangement angle of the lens, thereby further simplifying the complexity of the model and improving the calibration accuracy. In addition, the calibration model is closely related to the geometric model of the laser galvanometer scanning system, and the outgoing laser beam at other positions is calculated by the galvanometer rotation angle and the initial outgoing laser beam, without measuring or calculating the orientation of the incident beam.

[0071] Embodiment 2

[0072] Among them, since the system used in this method is usually already built, some parameters do not need to be calculated and can be obtained by simple measurement. For example, when X and Y are selected as the axis of the shaft, the four parameters X, Y, u, and v are fixed parameters that do not change with the change of the control signal. They only need to be measured in the equipment CAD model in advance and simply calculated.

[0073] Moreover, in the binocular camera coordinate system, the unit direction vector has two degrees of freedom, which can be calculated using two spherical angle parameters. Therefore, u can be calculated using the following formula:

[0074] in, is the angle between u and the z axis, and θ is the angle between the projection of u on the XY plane and the x axis. The XY plane refers to the plane formed by the rotation axis of the X mirror and the rotation axis of the Y mirror. The rotation axis of the X mirror is the X axis direction, the rotation axis of the Y mirror is the Y axis direction, and the Z axis direction refers to the direction perpendicular to both the X axis and the Y axis, and the X axis, Y axis, and Z axis intersect at the origin.

[0075] The same is true for v.

[0076] Embodiment 3

[0077] The difference between the embodiment 1 and the embodiment 1 is that in the embodiment, X and Y are respectively set to represent the two points closest to each other on the rotation axis of the X mirror and the rotation axis of the Y mirror, and the distance between the two is d, and the value of d can be directly measured and is usually provided by the manufacturer.

[0078] In this case, there is a formula Y=X+d(u×v).

[0079] Such an arrangement reduces the calculation parameters in S7, thereby improving the calibration accuracy.

[0080] Embodiment 4

[0081] In this embodiment, the control signal is obtained by: keeping the y signal unchanged and changing the x signal to obtain a plurality of first control signals; keeping the x signal unchanged and changing the y signal to obtain a plurality of second control signals.

[0082] Accordingly, in S7, the parameters of the calibration model are calculated respectively through the following steps:

[0083] Bringing multiple first control signals into the model and calculating to obtain a1, a2, a3 and u;

[0084] After multiple second control signals are introduced into the model, b1, b2, b3 and v are calculated.

[0085] Such a setting can effectively improve the calculation speed of each parameter in the calibration model, thereby improving the calibration efficiency.

[0086] Embodiment 5

[0087] In this embodiment, the calibration method also includes a parameter optimization step, such as Figure 4 As shown, the parameter optimization steps include:

[0088] S8, taking the objective function as the sum of squares of the difference between the direction of the outgoing laser beam calculated by the calibration model and the direction of the outgoing laser beam measured, and optimizing u, v, and m by a nonlinear optimization algorithm;

[0089] S9, taking the objective function as the sum of squares of the difference between the point coordinate position of the outgoing laser beam calculated by the calibration model and the point coordinate position of the outgoing laser beam measured, and optimizing X, Y, and P by a nonlinear optimization algorithm;

[0090] S10, taking the objective function as the sum of squares of the differences between the point coordinate position of the outgoing laser beam calculated by the calibration model and the point coordinate position of the outgoing laser beam actually measured, and optimizing a1, a2, a3, b1, b2, and b3 by a nonlinear optimization algorithm.

[0091] Such setting optimizes the parameters of the calibration model, thereby further improving the calibration accuracy.

[0092] Correspondingly, the parameter d in the third embodiment can also be optimized through step S9, thereby reducing the influence of the measurement error of d on the calibration model.

[0093] Embodiment 6

[0094] A computer storage medium stores a computer program, and when the computer program is executed by a processor, the method steps of any of the above embodiments are executed.

[0095] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0096] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0097] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0098] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A calibration method for a laser galvanometer scanning system based on a binocular camera, characterized in that: The system comprises X mirror, Y mirror, rotating device and control device, the X Mirror and Y The rotation axis of the mirror is fixed, and the rotating device is used to drive the X Mirror and Y The mirror rotates, and the control device is used to drive the rotating device through a control signal, and the control signal includes two signals for controlling X mirror, Y Mirror Rotating x Signal, y The method is used to calibrate the relationship between the control signal and the azimuth of the outgoing laser beam emitted by the system, and the method comprises the following steps: S1. Constructing a calibration model representing the relationship between the control signal and the orientation of the outgoing laser beam emitted by the system, wherein the calibration model comprises: α = a 1 x + a 2 x 2 + a 3 x 3 ， β = b 1 y + b 2 y 2 + b 3 y 3 ， R x = matrix (cos α + u without α ), R y = matrix (cos β + v without β ), l = R y R x m ， Q = R y ( R x ( P − X ) + X − Y ) + Y ； in, X , Y Respectively X The mirror's axis of rotation Y The three-dimensional coordinate point on the mirror's axis of rotation, u , v Respectively X The mirror's axis of rotation Y The unit direction vector of the mirror's rotation axis, P , m They represent the three-dimensional coordinate point and unit direction vector of the outgoing laser beam in the initial state, respectively. α express X Mirror x The rotation angle relative to the initial state under the signal, β express Y Mirror y The rotation angle relative to the initial state under the signal, R x , R y Respectively X mirror, Y The mirror rotates the light. l represents the direction of the outgoing laser beam, Q represents the point coordinate position of the outgoing laser beam, and the initial state is x Signal and y The signal is zero. a 1. a 2. a 3 are used to represent x and α The coefficients of the linear, quadratic, and cubic terms in the cubic polynomial of the relationship, b 1. b 2. b 3 are used to represent y and β The coefficients of the linear, quadratic, and cubic terms in the cubic polynomial of the relationship; S2, setting a curtain on one side of the laser beam emission direction of the system, and making the distance of the curtain relative to the system variable; S3, inputting the same set of control signals to the system respectively when the screen is at at least two different distances from the system, thereby obtaining a set of laser spots at each position of the screen; S4, determining the coordinates of each group of laser spots by a binocular camera to obtain multiple groups of spot coordinates; S5, extracting the spot coordinates corresponding to the same control signal, fitting a spatial straight line, and obtaining a corresponding relationship between the control signal and the orientation of the outgoing laser beam; S6. Extract the unit direction vector of the outgoing laser beam in the initial state according to the corresponding relationship. m and three-dimensional coordinates P ; S7, using the corresponding relationship, and then according to the formula in S1, calculate and obtain X , Y、u , v , a 1 、a 2 、a 3 、b 1 、b 2 、b 3. Thus, the calibration model is determined to realize the calibration of the laser galvanometer scanning system; The calibration method further comprises a parameter optimization step, wherein the parameter optimization step comprises: S8, taking the objective function as the sum of squares of the difference between the direction of the outgoing laser beam calculated by the calibration model and the direction of the outgoing laser beam measured, and optimizing it by a nonlinear optimization algorithm u , v , m； S9, taking the objective function as the sum of squares of the difference between the point coordinate position of the outgoing laser beam calculated by the calibration model and the point coordinate position of the outgoing laser beam measured, and optimizing it by a nonlinear optimization algorithm X, Y , P ; S10, taking the objective function as the sum of squares of the difference between the point coordinate position of the outgoing laser beam calculated by the calibration model and the point coordinate position of the outgoing laser beam measured, and optimizing it by a nonlinear optimization algorithm a 1 、a 2 、a 3. b 1 、b 2 、b 3; The same set of control signals is obtained in the following manner: Keep y The signal remains unchanged, x The signal changes to obtain multiple first control signals; keep x The signal remains unchanged, y The signal changes to obtain multiple second control signals.

2. The calibration method according to claim 1, characterized in that: In S7, the parameters of the calibration model are calculated by the following steps: After the plurality of the first control signals are brought into the model, the obtained a 1 、a 2 、a 3 and u ; After multiple second control signals are brought into the model, the obtained b 1 、b 2 、b 3 and v。 3. The calibration method according to claim 1, characterized in that: Said X , Y、u , v They are fixed parameters that do not change with the control signal.

4. The calibration method according to claim 3, characterized in that: Said u Calculated by the following formula: u= ( sin φ cos θ, sin φ sin θ, cos φ ),in, φ for u Angle with z axis ,θ for u The angle between the projection on the XY plane and the x-axis 。 5. The calibration method according to claim 1, characterized in that: Said X , Y Respectively X The mirror axis and Y The two closest points on the mirror's axis of rotation are d , then there is a formula Y = X + d ( u × v ).

6. The calibration method according to claim 5, characterized in that: In S9, it also includes d As the optimization parameter, X and d work out Y .

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 5 is performed.

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