A laser-assisted calibration method

Abstract

The present invention provides a laser-assisted calibration method. The steps of the calibration method are as follows: By adjusting the laser angles, make the three lasers all irradiate the measurement surface with laser light, collect a reference image and save it as a grayscale image, remove the calibration object and place a multi-dimensional translation stage, read the reference image and set it as the dark channel, collect the current grayscale image in real time and set it as the bright channel, synthesize the dark channel image and the bright channel image into a real-time composite image, place a calibration board on the translation stage to collect an image, extract the corner point information of the calibration board, and finally calculate the internal and external parameters of the camera under ideal conditions, and use the least squares method to obtain the distortion coefficients of radial distortion; The present invention can accurately calibrate the detection surfaces of parts with various different heights and appearances, and can accurately locate the detection surface of the measured object, improving the calibration accuracy.

Description

Technical Field

[0001] The present invention relates to the field of machine vision image detection, and particularly to a laser-assisted calibration method. Background Art

[0002] In applications such as image measurement, positioning, and machine vision, in order to determine the mutual relationship between the geometric position of a certain point on the surface of a spatial object in three-dimensional space and the corresponding point in a two-dimensional image, it is necessary to establish a geometric model of camera imaging. The parameters of the geometric model are the parameters of the camera, and the process of solving the parameters is the so-called camera calibration. The existing calibration method is to place a calibration plate on the surface to be measured, and calculate by extracting the coordinates of the grid corner points and the internal parameters of the camera. However, in this process, it is necessary to ensure that the calibration plate is placed directly above the surface to be measured, parallel or coincident with the measurement surface.

[0003] However, in actual measurement, due to the uncertainty of the surface shape of the calibration object, problems such as too small measurement surface, the measurement surface being blocked by other parts of the object, and inability to place the calibration plate often occur, resulting in the abnormal progress of the detection process. As Figures 1 - 4 shown, the measurement surface is located in the middle area inside the cylinder. For normal calibration, the calibration plate needs to be placed on the internal detection surface. If there is no suitable size calibration plate that can be placed on the internal measurement surface at this time, calibration cannot be carried out. Even if it is placed directly above the cylinder, it cannot be determined whether it is parallel to the detection surface, so it cannot be determined whether the calibration is effective. And when calibrating, it is required that the size of the calibration plate must be greater than 1 / 3 of the camera field of view. Both of these conditions need to be met to carry out calibration. Due to the existence of such problems, calibration cannot be carried out smoothly, thus affecting the measurement accuracy. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and provide a laser-assisted calibration method with simple structure and convenient use.

[0005] A laser-assisted calibration device for measuring the dimensions of parts with different heights includes a box body, a camera, an adjustment frame, a point light source, an adjustment table, and a calibration plate; the camera, the adjustment frame, and the adjustment table are arranged in the box body; the point light source is arranged on the adjustment frame; the calibration plate is arranged on the adjustment table; the box body is a hexahedron with one side open, the open side is the side surface of the box body, and the adjustment frame is arranged on the other three side surfaces of the box body; the camera is arranged on the top surface of the box body, and the adjustment table is arranged on the bottom surface of the box body.

[0006] Further, the adjustment frame is arranged around the camera.

[0007] A laser-assisted calibration method based on the above device is characterized by including the following steps:

[0008] S1: The point light source marks the surface of the part to be measured;

[0009] S2: The camera records the position of the mark at this time, takes away the part to be measured, places the adjustment table at the position to be measured, and the point light source marks the surface of the adjustment table;

[0010] S3: Change the position and attitude of the adjustment table so that the position of the point light source mark on the current surface of the adjustment table recorded by the camera coincides with the position of the point light source mark in S1;

[0011] S4: Set up a calibration board for calibration; use the calibration data to measure the size of the original part.

[0012] Furthermore, the steps of using a point light source for marking in S1 and S2 include:

[0013] S11: Adjust the adjustment bracket so that the point light source emits light towards the detection surface;

[0014] S12: The light emitted by the point light source is reflected by the detection surface and transmitted to the camera;

[0015] S13: The camera collects real-time images.

[0016] Furthermore, S4 includes the following steps:

[0017] S41: Transform from the world coordinate system to the camera coordinate system;

[0018] S42: Transform from the camera coordinate system to the imaging plane coordinate system, where the process of transforming from the camera coordinate system to the imaging plane coordinate system includes the calibration process;

[0019] S43: Correct the imaging plane coordinate system;

[0020] S44: Transform from the corrected imaging plane coordinate system to the image coordinate system;

[0021] S45: Determine the total internal and external parameters of the camera to complete the calibration.

[0022] Furthermore, in S41, the transformation from the world coordinate system to the camera coordinate system includes converting point P w to point P c , specifically through the following formula:

[0023] P c = R · P w + T

[0024] where R represents the rotation matrix, T represents the translation vector, and R includes three rotation angles α, β, γ; the rotation matrix R(α, β, γ) is expressed as:

[0025]

[0026] Among them, α represents the angle between the X-axis of the camera coordinate system and the world coordinate system, β represents the angle between the Y-axis of the camera coordinate system and the world coordinate system, γ represents the angle between the Z-axis of the camera coordinate system and the world coordinate system; P c The coordinate value in the camera coordinate system is expressed as (x c , y c , z c ); T = (t x , t y , t z ).

[0027] Furthermore, in the step S42, during the process of converting from the camera coordinate system to the imaging plane coordinate system, it is necessary to convert P c to the imaging plane coordinate system, and the conversion process depends on the following conversion relational formula:

[0028]

[0029] Among them, f represents the focal length of the camera; u, v represent the coordinate values of point P in the imaging plane coordinate system.

[0030] Furthermore, in the step S43, correcting the imaging plane coordinate system includes:

[0031]

[0032] Among them, the parameter k represents the distortion magnitude of the radial distortion; represents the true imaging plane coordinate value of point P after correction.

[0033] Furthermore, in the step S44, converting the coordinate of point P in the ideal imaging plane coordinate system to the image coordinate system includes:

[0034]

[0035] Among them, C x , C y are the coordinate values of the vertical projection of the projection center in the imaging plane coordinate system, S x , S y are the distances between adjacent pixels of the image sensor in the horizontal and vertical directions.

[0036] Furthermore, in the step S45, the process of determining the total internal and external parameters of the camera is as follows: Place the checkerboard calibration board above the adjustment table, use the camera to take the current calibration board image, first obtain the corner coordinates m i,j of the checkerboard from the calibration board image, and the m i,j is in the image coordinate system; Through the following formula, calculate the distance d(c) between the projected coordinates Ti(Mi, c):

[0037]

[0038] By jointly solving two or more images with a calibration board, the minimum value of d(c) is obtained to determine the total internal and external camera parameters c = (f, k, S x , S y , C x , C y , t x , t y , t z , α, β, γ), completing the camera calibration process.

[0039] The beneficial effects of the present invention are as follows:

[0040] By setting a point light source assist and an adjustment table, the detection surfaces of parts with different heights and different appearances can be accurately calibrated;

[0041] A plane positioning method is introduced, which can accurately locate the detection surface of the measured object and improve the calibration accuracy;

[0042] By correcting the imaging plane coordinate system and correcting the distortion value generated during the imaging process, the calibration is made more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a checkerboard calibration board;

[0044] Figure 2 is that the measurement surface is located in the middle area inside the cylinder during traditional calibration;

[0045] Figure 3 is that the calibration board is placed on the detection surface inside the cylinder during traditional calibration;

[0046] Figure 4 is that the calibration board is placed directly above the cylinder during traditional calibration;

[0047] Figure 5 is a simplified schematic diagram of the calibration device of the present invention;

[0048] Figure 6 is a simplified top view of the calibration device of the present invention;

[0049] Figure 7 is a structural diagram of the calibration device in Embodiment 1 of the present invention;

[0050] Figure 8 is a front view of the calibration device in Embodiment 1 of the present invention;

[0051] Figure 9 is a schematic diagram of the light path reflection of surfaces with different inclinations of the present invention;

[0052] Figure 10 Schematic diagram of the adjustment table of the present invention;

[0053] Figure 11 Bottom view of the upper base of the present invention;

[0054] Figure 12 Three-dimensional view of the upper base of the present invention;

[0055] Figure 13 Three-dimensional view of the adjustment frame of the present invention;

[0056] Figure 14 Simplified structural diagram for positioning the detection surface of the measurement object of the present invention;

[0057] Figure 15 Schematic diagram for detecting the detection surface of the measurement object of the present invention;

[0058] Figure 16 Schematic diagram of the camera imaging on the detection surface of the present invention;

[0059] Figure 17 Schematic diagram for detecting the adjustment table of the present invention;

[0060] Figure 18 Schematic diagram of the imaging for the adjustment table of the present invention to restore the measurement surface;

[0061] Figure 19 Principle diagram of plane imaging of the present invention;

[0062] Figure 20 Flow chart of the present invention.

[0063] Explanation of the reference numerals in the drawings: box body 1, camera 2, adjustment frame 3, fixed seat 31, curved arm 32, point light source 4, adjustment table 5, vertical rod 51, reflecting surface 52, knob 53, height knob 531, positioning knob 532, support rod 54, connecting rod 541, base 55, upper base 551, lower base 552, sliding rod 56, slider 57, fixed block 58, height adjustment rod 59, calibration plate 6, part to be measured ⑦. Detailed implementation manners

[0064] The following specifically illustrates the implementation manners of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0065] It should be noted that the illustrations provided in the following embodiments only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the drawings, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, quantities, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0066] Embodiment 1:

[0067] As Figures 5 - 8 shown, a laser-assisted calibration device for measuring the dimensions of parts with different heights includes a box body 1, a camera 2, an adjustment frame 3, a point light source 4, an adjustment table 5, and a calibration plate 6.

[0068] The box body 1 is a hexahedron with one side open. One of the open sides is the side surface of the box body 1. Three other side surfaces of the box body 1 are provided with adjustment frames 3. The top surface of the box body 1 is provided with a camera 2, and the bottom surface is provided with an adjustment table 5. The adjustment table 5 is only placed on the bottom surface of the box body, and the adjustment table 5 can move on the bottom surface of the box body. The point light source 4 is arranged on the adjustment frame 3. The calibration plate 6 is arranged on the adjustment table 5. The material of the box body 1 can be a metal material. In this embodiment, iron material is selected. At the same time, in order to facilitate the operation of the operator, a base is provided below the bottom surface of the box body, so that the horizontal height of the adjustment table is increased. In order to facilitate the movement of the calibration device, universal wheels are provided at the bottom of the box body, enabling the calibration device to move arbitrarily.

[0069] As Figure 13 shown, the adjustment frame 3 is arranged around the camera 2. The adjustment frame 3 is a universal adjustment frame 3, which can adjust the horizontal height, tilt angle, and horizontal position. The adjustment frame 3 includes a fixed seat 31 and a curved arm 32. The fixed seat 31 of the adjustment frame 3 is provided with a magnet, aiming to enable the adjustment frame 3 to be adsorbed on the box body 1, and at the same time, the height and angle of the adjustment frame 3 can be adjusted. The curved arm 32 is hinged to the fixed seat 31. A hinge joint is provided at one end of the fixed seat 31 away from the magnet. One end of the hinge joint is provided with a thread to connect with the fixed seat 31, and the other end of the hinge joint is provided with a spherical hinge block. One end of the curved arm 32 is hinged to the hinge joint of the fixed seat 31, and the other end of the curved arm 32 is provided with a similar hinge joint, which is connected to the point light source. The curved arm 32 is integrally composed of two parallel elliptical sheets. A threaded connection is provided between the two parallel elliptical sheets. Circular cutouts are provided at both ends of the elliptical sheet, and the cutouts cooperate with the spherical hinge block.

[0070] As Figure 7 、 13 shown, there are at least three point light sources 4. One point light source 4 is arranged on one adjustment frame 3, and a thread is provided between the point light source 4 and the adjustment frame 3. In this embodiment, the point light source 4 is a semiconductor laser, and the number of point light sources 4 is three.

[0071] As shown Figures 10 - 12 in the figure, the adjustment table 5 includes a vertical rod 51, a reflecting surface 52, a knob 53, a support rod 54, a base 55, and a sliding rod 56. The base includes an upper base 551 and a lower base 552. The reflecting surface 52 is disposed on the upper surface of the upper base 551, and a vertical rod 51 is disposed between the reflecting surface 52 and the upper base 551. There are four vertical rods 51, and the four vertical rods 51 are disposed at the four corners of the reflecting surface 52. There are a total of four sliding rods 56. Taking two sliding rods 56 as a group, the four sliding rods 56 are divided into two groups. The sliding rods 56 in the same group are parallel and in the same horizontal plane. The two groups of sliding rods 56 are respectively disposed on the lower surface of the upper base 551 and the upper surface of the lower base 552. The knob 53 includes a height knob 531 and a positioning knob 532. The knob is disposed on the upper base 551 and is located at one end of the sliding rod 56. The positioning knob 532 can lock the height knob 531 to prevent the height of the adjustment table from changing during the calibration process. A support rod 54 is also disposed between the upper base 551 and the lower base 552. The support rods 54 are cross - arranged. The support rods are disposed on both sides of the sliding rod 56, and a connecting rod 541 is disposed between the support rods on both sides for the purpose of stabilizing the support of the support rods. A slider 57 and a fixed block 58 are disposed between the support rod 54 and the sliding rod 56. One slider 57 and one fixed block 58 are disposed on one sliding rod 56. The slider 57 is sleeved on the sliding rod 56, and the slider 57 can slide along the sliding rod 56; the fixed block 58 is disposed at one end of the sliding rod 56, and the fixed block 58 is fixedly connected to the base. Both sides of the slider 57 and the fixed block 58 are hinged to the support rod, and the support rod 54 can rotate around the hinge point. A height adjustment rod 59 is disposed on the slider 57 of the sliding rod 56 disposed on the upper base 551, and the height adjustment rod 59 is connected to the slider 57 of the upper base 551. The height adjustment rod 59 can extend or contract as the height knob 531 rotates, pushing the slider 57 located on the upper base 551 to slide along the sliding rod 56, thereby adjusting the height of the adjustment table.

[0072] A laser - assisted calibration method for measuring the dimensions of parts with different heights, the calibration method comprising the following steps:

[0073] S1: The semiconductor laser marks the surface of the part 7 to be measured; the semiconductor laser is disposed on the adjustment bracket 3 on both sides of the lens; the adjustment bracket 3 is a universal adjustment bracket 3, and the horizontal height, tilt angle, and horizontal position of the semiconductor laser can be adjusted through the adjustment bracket 3;

[0074] S2: The camera 2 records the position of the mark at this time, removes the part 7 to be measured, places the adjustment table 5 at the position to be measured, and the point light source 4 marks the surface of the adjustment table 5;

[0075] S3: Change the position and attitude of the adjustment table 5 so that the position of the point light source 4 marked on the surface of the current adjustment table 5 recorded by the camera 2 coincides with the position of the point light source 4 marked in S1;

[0076] S4: Set up the calibration board 6 for calibration;

[0077] S5: Use the calibration data to measure the dimensions of the original part.

[0078] As Figure 9 、 14 -20 shows that during the marking process of S1 and S2, first adjust the adjustment frame 3 so that the point light source 4 emits light towards the detection surface of the part 7 to be measured. In this embodiment, the point light source 4 uses a semiconductor laser. Secondly, the light emitted from the side of the point light source 4 to the camera 2 is transmitted to the camera 2 after being reflected by the detection surfaces with different inclinations, and the reflection is diffuse reflection. Since the positions where the point light source 4 irradiates on the detection surface are different, the imaging positions of the point light source 4 in the camera 2 will also be different. Therefore, three points that are not on the same straight line in the image obtained by the camera 2 can determine the position of a plane in space, and the position of the plane can be recorded by the imaging positions of the bright points on the image. The present invention needs to set at least three semiconductor lasers to achieve positioning, and three semiconductor lasers are set to achieve positioning in this embodiment.

[0079] In this embodiment, the three semiconductor lasers emit laser light onto the detection surface of the part 7 to be measured, and the images of three dark points can be captured by the camera 2; save the images of the dark points, and then replace them with the adjustment table 5 without changing the attitude of the semiconductor lasers. Since there may be differences in the height and inclination angle of the adjustment table 5 and the detection surface of the part 7 to be measured, the positions of the three laser points may all have deviations. The camera 2 captures the image of the adjustment table 5 in real time, and through the image processing algorithm, the image of the detection surface of the part 7 to be measured is synthesized with the image of the adjustment table 5 in real time to observe the positions of the bright points. Adjust the heights of the four vertical rods 51 of the adjustment table 5 to control the height and inclination angle of the reflection surface 52 of the adjustment table 5. When the height and level of the adjustment table 5 change, the positions of the bright points will also change in real time. Observe the imaging of the camera 2. When the bright points move to coincide with the dark points, it means that the plane where the detection surface of the part 7 to be measured is located coincides with the plane where the reflection surface 52 of the adjustment table 5 is located. After that, the calibration board 6 can be placed above the adjustment table 5 for calibration.

[0080] As Figure 15 shown, step S4 includes the following steps:

[0081] S41: First, transform from the world coordinate system to the camera 2 coordinate system;

[0082] S42: Then transform from the camera 2 coordinate system to the imaging plane coordinate system;

[0083] S43: Correct the imaging plane coordinate system;

[0084] S44: Transform from the corrected imaging plane coordinate system to the image coordinate system;

[0085] S45: Determine the total internal and external parameters of Camera 2 to complete the calibration.

[0086] In S41, the transformation from the world coordinate system to the Camera 2 coordinate system includes transforming the point P w into the point P c , specifically through the following formula:

[0087] P c = R·P w + T

[0088] where R represents the rotation matrix and T represents the translation vector. R includes three rotation angles α, β, and γ. The rotation matrix R(α, β, γ) is expressed as:

[0089]

[0090] where T = (t x , t y , t z ) is a translation vector; α represents the angle between the X-axis of the Camera 2 coordinate system and the world coordinate system, β represents the angle between the Y-axis of the Camera 2 coordinate system and the world coordinate system, and γ represents the angle between the Z-axis of the Camera 2 coordinate system and the world coordinate system. T and R are the external parameters of Camera 2, which are used to describe the position of Camera 2 in the world coordinate system. The world coordinate system can be transformed to the Camera 2 coordinate system through the external parameters; The coordinate value of P c in the Camera 2 coordinate system is expressed as (x c , y c , z c ).

[0091] In S42, during the process of transforming from the Camera 2 coordinate system to the imaging plane coordinate system, it is necessary to transform P c to the imaging plane coordinate system, and the transformation process depends on the following transformation relationship:

[0092]

[0093] where f represents the focal length of Camera 2; u and v represent the coordinate values of point P in the imaging plane coordinate system.

[0094] Due to lens distortion, the obtained imaging plane coordinate values u and v here have errors compared with the true imaging plane coordinate values. To convert the imaging plane obtained in S42 into the true imaging plane, it is also necessary to go through S43: Radial distortion correction of the lens.

[0095] The arithmetic formula for radial distortion correction of the lens is as follows:

[0096]

[0097] Among them, the parameter k represents the distortion magnitude of radial distortion; represents the true imaging plane coordinate value of point P after correction.

[0098] In S44, the coordinates of point P in the ideal imaging plane coordinate system are converted to the image coordinate system, including:

[0099]

[0100] where C x , C y are the coordinate values of the vertical projection of the projection center in the imaging plane coordinate system, S x , S y is the distance between adjacent pixels of the image sensor in the horizontal and vertical directions; (f, k, S x , S y , C x , C y ) are the internal parameters of camera 2.

[0101] In S45, the process of determining the total internal and external parameters of camera 2 is as follows: Place the checkerboard calibration plate 6 above the adjustment table 5, and use camera 2 to capture the current calibration plate 6 image. First, perform algorithm processing on the calibration plate 6 image obtained by camera 2, and obtain the corner coordinates m i,j of the checkerboard from the calibration plate 6 image. The m i,j is in the image coordinate system. Through the following formula, calculate the distance d(c) between the projected coordinates Ti(Mi, c):

[0102]

[0103] By jointly solving two or more images with the calibration plate 6, find the minimum value of d(c) to determine the parameters of camera 2. Obtain the total internal and external parameters of camera 2 c = (f, k, S x , S y , C x , C y , t x , t y , t z , α, β, γ), and complete the calibration process of camera 2.

[0104] The above description is only a specific example of the present invention and does not constitute any limitation to the present invention. Obviously, for professionals in the field, after understanding the content and principle of the present invention, various modifications and changes in form and details may be made without departing from the principle and structure of the present invention. However, these corrections and changes based on the idea of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A laser-assisted calibration method, characterized in that, Based on a laser-assisted calibration device, the following steps are included: The laser-assisted calibration device includes a box body, a camera, an adjustment frame, a point light source, an adjustment table, and a calibration plate. The camera is arranged on the top surface of the box body, the adjustment table is arranged on the bottom surface, the adjustment frame is arranged on the side surface, and the point light source is arranged on the adjustment frame; the calibration plate is arranged on the adjustment table, and the adjustment frame is arranged around the camera. S1: The point light source marks the surface of the part to be measured. S2: The camera records the position of the mark at this time, removes the part to be measured, places the adjustment table at the position to be measured, and the point light source marks the surface of the adjustment table. S3: Change the position and attitude of the adjustment table so that the position of the point light source mark on the surface of the current adjustment table recorded by the camera coincides with the position of the point light source mark in S1. The point light source uses a semiconductor laser. Three semiconductor lasers emit laser light onto the detection surface of the part to be measured, and the images of three dark spots can be captured by the camera; save the images of the dark spots, then replace it with the adjustment table without changing the attitude of the semiconductor laser, collect the images of the adjustment table in real time through the camera, and through the image processing algorithm, synthesize the images of the detection surface of the part to be measured and the images of the adjustment table in real time, observe the position of the bright spot, adjust the height of the four vertical rods of the adjustment table to control the height and inclination angle of the reflection surface of the adjustment table. When the height and level of the adjustment table change, the position of the bright spot will also change in real time. Observe the imaging of the camera. When the bright spot moves to coincide with the dark spot, it means that the plane where the detection surface of the part to be measured is located coincides with the plane where the reflection surface of the adjustment table is located, and the calibration plate can be placed above the adjustment table for calibration. S4: Set the calibration plate for calibration; use the calibration data to measure the size of the part to be measured.

2. The laser-assisted calibration method according to claim 1, wherein, The steps of using the point light source for marking in S1 and S2 include: S11: Adjust the adjustment frame so that the point light source emits light towards the detection surface. S12: The light emitted by the point light source is reflected by the detection surface and transmitted to the camera. S13: The camera collects real-time images.

3. The laser-assisted calibration method according to claim 2, wherein S4 includes the following steps: S41: Transform from the world coordinate system to the camera coordinate system. S42: Transform from the camera coordinate system to the imaging plane coordinate system, and the process of transforming from the camera coordinate system to the imaging plane coordinate system includes the calibration process. S43: Correct the imaging plane coordinate system. S44: Transform from the corrected imaging plane coordinate system to the image coordinate system. S45: Determine the total internal and external parameters of the camera to complete the calibration.

4. The laser-assisted calibration method according to claim 3, wherein In S41, the conversion from the world coordinate system to the camera coordinate system includes converting point P w to point P c , specifically through the following formula: P c =R·P w +T where R represents the rotation matrix and T represents the translation vector. R includes three rotation angles; the rotation matrix R is expressed as: ； Wherein, represents the angle between the X-axis of the camera coordinate system and the world coordinate system, represents the angle between the Y-axis of the camera coordinate system and the world coordinate system, represents the angle between the Z-axis of the camera coordinate system and the world coordinate system; P c The coordinate value in the camera coordinate system is expressed as ( ); T = .

5. A laser-assisted calibration method according to claim 4, characterized in that, In S42, during the process of converting from the camera coordinate system to the imaging plane coordinate system, it is necessary to convert P c to the imaging plane coordinate system, and the conversion process depends on the following conversion relation: ； where f represents the focal length of the camera; represents the coordinate value of point P in the imaging plane coordinate system.

6. The laser-assisted calibration method according to claim 5, wherein In S43, correcting the imaging plane coordinate system includes: ； where the parameter k represents the distortion magnitude of the radial distortion; , represent the true imaging plane coordinate values of point P after correction.

7. A laser-assisted calibration method according to claim 6, wherein In S44, the coordinates of point P in the ideal imaging plane coordinate system are converted to the image coordinate system, including: ； Among them, C x , C y is the coordinate value of the perpendicular projection of the projection center on the imaging plane coordinate system, S x , S y is the distance between adjacent pixels of the image sensor in the horizontal and vertical directions, and r and c represent the coordinates of point P in the ideal imaging plane coordinate system The converted image coordinate values.

8. A laser-assisted calibration method according to claim 7, wherein In S45, the process of determining the total internal and external parameters of the camera is as follows: Place the checkerboard calibration plate above the adjustment table, and use the camera to capture the current calibration plate image. First, obtain the corner coordinates of the checkerboard from the calibration plate image , the in the image coordinate system; Through the following formula, calculate the deviation distance between the corner coordinates and the coordinate : : ； By jointly solving two or more images with calibration boards, the minimum value of is obtained to determine the total internal and external camera parameters =(f, k, S x , S y , C x , C y , , , , α, β, γ), and complete the camera calibration process.

Images