Calibration device and calibration method for line laser camera

Abstract

The present invention discloses a calibration device and a calibration method for a line laser camera, comprising a workbench, a calibration plate, a light source and a three-axis fine-tuning device, wherein the light source is arranged on the three-axis fine-tuning device, and a plurality of calibration groups are evenly arranged on the calibration plate, wherein two adjacent calibration groups are arranged in parallel and equidistantly, and each calibration group comprises a plurality of calibration units arranged equidistantly and at intervals, wherein the calibration unit has a calibration cusp, and the calibration cusps of the plurality of calibration units of each calibration group are staggered, and a step is arranged at the edge of the calibration plate, and a groove is arranged on the step, and the groove is arranged in the horizontal direction, and the groove is at the same height as the calibration cusps of each calibration unit. The present invention sets a series of calibration units arranged in a staggered manner according to the camera field of view, and only one image is required, and no other auxiliary mobile platforms are required, so that the data of all pixel points can be obtained, matrix transformation calculation can be performed, and relevant parameters inside the camera can be obtained to complete the calibration.

Description

Technical Field

[0001] This invention relates to the field of camera calibration technology, specifically to a calibration device and calibration method for a line laser camera. Background Technology

[0002] Structured light 3D scanning technology, due to its advantages such as low cost, non-contact operation, high precision, and high efficiency, has been widely used in product design and manufacturing, industrial measurement, quality inspection, medicine, film and entertainment, and other industries, and is hailed as the most promising 3D measurement method. Structured light 3D scanning technology achieves 3D scanning by actively controlling the light source, and has higher reliability compared to other 3D scanning technologies. Before performing structured light 3D reconstruction, the structured light system must be calibrated, that is, the internal parameters of the camera and projection equipment in the structured light system, as well as the conversion relationship between the two, are obtained, which are also called external parameters. The accuracy of calibration directly affects the quality of 3D reconstruction.

[0003] Currently, camera calibration technology is mature. The mainstream calibration of line laser cameras generally uses calibration boards with special features such as black and white checkerboard or dots. These boards all require a moving platform to acquire pixels and need to be moved continuously to calibrate and acquire data. However, the moving process has errors in repetitive positioning accuracy, as well as errors in manual point selection when acquiring pixels. Therefore, the calibration results are difficult to achieve high accuracy and the calibration efficiency is low.

[0004] In view of this, the inventors of this case conducted in-depth research on the above-mentioned problems, which led to the creation of this case. Summary of the Invention

[0005] The purpose of this invention is to provide a calibration device for a line laser camera that has high calibration accuracy, fast calibration efficiency, and is easy to use.

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

[0007] A calibration device for a line laser camera includes a worktable, a calibration plate, a light source for emitting a light beam, and a three-axis fine-tuning device for adjusting the illumination direction of the light source. The calibration plate is disposed on the worktable, which is located on one side of the three-axis fine-tuning device. The light source is disposed on the three-axis fine-tuning device. Several calibration groups are evenly arranged on the calibration plate, with adjacent calibration groups arranged parallel and equidistantly. Each calibration group includes multiple calibration units arranged equidistantly and at intervals. Each calibration unit has a calibration tip. The calibration tips of the multiple calibration units in each calibration group are staggered. Each calibration unit extends upward. A step is provided at the edge of the calibration plate. A T-shaped groove is formed on the step in the horizontal direction. The groove extends from one side of the step to the other side of the step. The groove is arranged in the horizontal direction and is at the same height as the calibration tips of each calibration unit.

[0008] As a preferred embodiment of the present invention, the arrangement direction of each calibration group is defined as the Y-axis, the horizontal direction perpendicular to the arrangement direction of each calibration group is defined as the X-axis, and the vertical direction perpendicular to the arrangement direction of each calibration group is defined as the Z-axis.

[0009] The three-axis fine-tuning device is mounted on the base plate. The three-axis fine-tuning device includes a fine-tuning base plate, a Y-axis rotating plate, a Z-axis rotating plate, a Z-axis linkage plate, an X-axis rotating plate, a first rotating shaft, a second rotating shaft, a third rotating shaft, a first compression spring, a second compression spring, a third compression spring, a first pressure plate, a second pressure plate, a third pressure plate, a first spherical differential switch for adjusting the gap between the Y-axis rotating plate and the fine-tuning base plate, a second spherical differential switch for adjusting the gap between the Y-axis rotating plate and the X-axis rotating plate, and a third spherical differential switch for adjusting the gap between the X-axis rotating plate and the Z-axis rotating plate.

[0010] The fine-tuning base plate is provided with the Y-axis rotating plate along the X-axis direction. One side of the fine-tuning base plate and the side opposite to the Y-axis rotating plate are hinged through the first rotating shaft. The first rotating shaft is provided along the Y-axis direction. The first pressure plate is provided on the side of the fine-tuning base plate away from the first rotating shaft. One end of the first pressure plate is fixedly provided on the fine-tuning base plate. The first pressure plate extends above the Y-axis rotating plate. The first spherical differential switch is provided above the first pressure plate. The telescopic rod of the first spherical differential switch passes through the first pressure plate and abuts against the Y-axis rotating plate. One end of the first compression spring abuts against the fine-tuning base plate, and the other end of the first compression spring abuts against the Y-axis rotating plate.

[0011] The Y-axis rotating plate is provided with the X-axis rotating plate along the Z-axis direction. One side of the Y-axis rotating plate and the side opposite to the X-axis rotating plate are hinged by the second rotating shaft. The second rotating shaft is provided along the X-axis direction. The second pressure plate is provided on the side of the Y-axis rotating plate away from the second rotating shaft. One end of the second pressure plate is fixedly provided on the Y-axis rotating plate. The second pressure plate extends above the X-axis rotating plate. The second spherical differential switch is provided above the second pressure plate, and the telescopic rod of the second spherical differential switch passes through the second pressure plate and abuts against the X-axis rotating plate. One end of the second compression spring abuts against the Y-axis rotating plate, and the other end of the second compression spring abuts against the X-axis rotating plate.

[0012] The Z-axis linkage plate is vertically mounted on the X-axis rotating plate. The Z-axis rotating plate is located on one side of the Z-axis linkage plate. The Z-axis linkage plate is vertically mounted. One side of the Z-axis linkage plate and the side opposite to the Z-axis rotating plate are hinged by a third rotating shaft. The third rotating shaft is located along the Z-axis direction. The third pressure plate is located on the side of the Z-axis linkage plate away from the third rotating shaft. One end of the third pressure plate is fixedly mounted on the Z-axis linkage plate. The third pressure plate extends above the Z-axis rotating plate. The third spherical differential switch is located above the third pressure plate, and the telescopic rod of the third spherical differential switch passes through the third pressure plate and abuts against the Z-axis rotating plate. One end of the third compression spring abuts against the X-axis rotating plate, and the other end of the third compression spring abuts against the Z-axis linkage plate.

[0013] In a preferred embodiment of the present invention, the three-axis fine-tuning device is provided with a housing for placing the light source and the camera. The housing is a hollow housing, and the inner cavity of the housing is provided with an accommodating space for placing the light source and the camera. The light source is positioned above the camera.

[0014] In a preferred embodiment of the present invention, the light source comprises at least one of a light-emitting diode and a laser light source.

[0015] The present invention also provides another objective, which is to provide a calibration method for a structured light 3D scanning camera that can quickly and accurately acquire calibration data information for reading and conversion.

[0016] To achieve the above objectives, the solution of the present invention is:

[0017] A calibration method using a calibration device for a line laser camera includes the following steps:

[0018] S1: Install the camera to be calibrated on the three-axis fine-tuning device;

[0019] S2: Adjust the laser plane of the light source. By adjusting the three-axis fine-tuning device, the laser beam of the light source is made to irradiate the groove of the calibration plate, that is, the laser beam of the light source is made to descend and irradiate the calibration tips of each calibration unit, so as to determine whether the laser plane of the light source coincides with the plane of all calibration tips of the calibration plate.

[0020] S3: Create a visual matching template in advance so that the camera can acquire data of all pixels. Set the cusp of any of the calibration units as the reference origin (0,0) and calculate the coordinates of the cusps of other calibration units (X1,Y1), (X2,Y2)...(Xn,Yn).

[0021] S4: Start the camera software and begin acquiring the pixel positions (A1,B1), (A2,B2)...(An,Bn) of all the cusps in each calibration unit within the camera's field of view. Perform a matrix transformation algorithm with the actual calibrated cusp data to calculate the internal parameters of the camera, i.e., the calibration completion conversion equation.

[0022] The advantages of this invention using the above technical solution are as follows: The calibration device of this invention sets up a series of staggered calibration cusps. With only one image and without any other auxiliary moving platforms, it can acquire data for all pixels. The calibration device of this invention has high calibration accuracy, fast calibration efficiency, and is easy to use. When the light source emits a beam, the three-axis fine-tuning device is adjusted so that the light beam illuminates the calibration cusps of all calibration units on the calibration board, calibrating the relative position of the camera and the calibration board. This allows for quick and accurate acquisition of data information from the calibration board, which is then transmitted to a computer for reading and calculation. This significantly improves the efficiency and accuracy of batch camera calibration. This invention sets up a series of staggered calibration units according to the camera's field of view. With only one image and without any other auxiliary moving platforms, it can acquire data for all pixels, perform matrix transformation calculations, obtain relevant internal parameters, and complete the calibration. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention;

[0024] Figure 2 This is a side view of the present invention;

[0025] Figure 3 This is a schematic diagram of the calibration plate in this invention;

[0026] Figure 4 This is a schematic diagram of the Y-axis calibration plate in this invention;

[0027] Figure 5 This is a top view of the calibration plate in this invention;

[0028] Figure 6 This is a schematic diagram of the X-axis calibration plate in this invention;

[0029] Figure 7 This is a schematic diagram of the three-axis fine-tuning device in this invention;

[0030] Figure 8 This is a partial cross-sectional view of the three-axis fine-tuning device in this invention.

[0031] In the picture:

[0032] Workbench 1, Calibration plate 2, Calibration group 21, First calibration group 211, Second calibration group 212, Third calibration group 213, Calibration unit 22, First calibration unit 221, Second calibration unit 222, Third calibration unit 223, Step 23, Groove 231, Light source 3, Camera 4, Three-axis fine adjustment device 5, Fine adjustment base 50, Fine adjustment base plate 51, First slot 511, Y-axis rotating plate 52, Second slot 521, Z-axis rotating plate 53, Z-axis linkage plate 54, Third slot 541, X-axis rotating plate 55, First rotating shaft 561, Third rotating shaft 563, First pressure plate 581, Second pressure plate 582, Third pressure plate 583, First spherical differential switch 591, Second spherical differential switch 592, Third spherical differential switch 593, Housing 6, Accommodation space 61, Light shield 62, Lens 63, Transparent glass 64. Detailed Implementation

[0033] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0034] This invention aims to improve upon the shortcomings of existing technologies, especially in the case of cameras requiring calibration references at the factory or during actual use. Often, actual objects used in the field are used as references, but this is not very standardized and affects usability.

[0035] For ease of description, this embodiment defines the arrangement direction of each calibration group 21 (which will be described in detail below) as the Y-axis, the horizontal direction perpendicular to the arrangement direction of each calibration group 21 as the X-axis, and the vertical direction perpendicular to the arrangement direction of each calibration group 21 as the Z-axis.

[0036] like Figures 1-6 As shown:

[0037] The present invention provides a calibration device for a line laser camera, including a worktable 1, a calibration plate 2, a light source 3 for emitting a light beam, a three-axis fine-tuning device 5 for adjusting the irradiation direction of the light source 3, and a camera 4. The calibration plate 2 is disposed on the worktable 1, the three-axis fine-tuning device 5 is disposed on one side of the worktable 1, and the light source 3 is disposed on the three-axis fine-tuning device.

[0038] Preferably, the light source 3 includes at least one of light-emitting diodes and laser light sources, and the camera 4 can be a conventional CCD camera.

[0039] like Figure 5 As shown: Several calibration groups 21 are evenly arranged along the X-axis on the calibration plate 2. Adjacent calibration groups 21 are parallel and equidistant. For ease of description, we designate the first row of calibration groups 21 as the first calibration group 211, the second row as the second calibration group 212, and so on. It is worth noting that the number of calibration units on each calibration group 21 is the same. Due to repetition and for simplicity, in the accompanying drawings and specification, they are simply referred to as belonging to the first calibration group 211, the second calibration group 212, the third calibration group 213, the first calibration unit 221 (described in detail below), the second calibration unit 222, and the third calibration unit 223, respectively.

[0040] Each calibration group 21 includes multiple calibration units 22 arranged at equal intervals. Each calibration unit 22 extends upward and has a calibration cusp. The calibration cusps of the multiple calibration units 22 in each calibration group 21 are staggered.

[0041] In simple terms, the first calibration group 211, the second calibration group 212, and the third calibration group 213 are arranged in parallel, and the distance between the first calibration group 211 and the second calibration group 212 and the distance between the second calibration group 212 and the third calibration group 213 are equal. Taking the first calibration group 221 as an example, the distance between the first calibration unit 221 and the second calibration unit 222 and the distance between the second calibration unit 222 and the third calibration unit 223 are equal.

[0042] The calibration cusp of the second calibration unit 222 of the second calibration group 212 is located between the first calibration unit 221 and the second calibration unit 222 of the first calibration group 211. The calibration cusp of the second calibration unit 222 of the third calibration group 212 is located between the first calibration unit 221 and the second calibration unit 222 of the second calibration group 212, and is located between the first calibration unit 221 and the second calibration unit 222 of the first calibration group 211, and so on. The calibration cusps of the second calibration units 222 of the subsequent rows of calibration groups 21 all fall between the first calibration units 221 and the third calibration units of all the preceding rows of calibration groups 21, and do not obstruct each other, i.e. Figures 4-5 As shown, when viewed from a certain reference direction, each calibration unit 22 mutually blocks each other.

[0043] A step 23 is provided at the edge of the calibration plate 2. A groove 231 is provided along the Y-axis of the step 23. The groove 231 is a gap of 0.1-0.3mm. The groove 231 extends from one side of the step 23 to the other side of the step 23. The groove 231 is set in the horizontal direction and is at the same height as the calibration tip of each calibration unit 22.

[0044] like Figure 7-Figure 8 As shown:

[0045] The three-axis fine-tuning device 5 is mounted on the base plate 1. The three-axis fine-tuning device 5 can adjust the three-axis angular freedom of the camera 4XYZ, thereby adjusting the position of the camera 4 and the toothed calibration plate 41.

[0046] The three-axis fine-tuning device 5 includes a fine-tuning base 50, a fine-tuning base plate 51, a Y-axis rotating plate 52, a Z-axis rotating plate 53, a Z-axis linkage plate 54, an X-axis rotating plate 55, a first rotating shaft 561, a second rotating shaft (not shown in the figure), a third rotating shaft 563, a first compression spring (not shown in the figure), a second compression spring (not shown in the figure), a third compression spring (not shown in the figure), a first pressure plate 581, a second pressure plate 582, a third pressure plate 583, a first spherical differential switch 591, a second spherical differential switch 592, and a third spherical differential switch 593.

[0047] Specifically, in this embodiment, the first spherical differential switch 591, the second spherical differential switch 592, and the third spherical differential switch 593 all adopt commercially available spherical differential switches of model S65-1Q. The first pressure plate 581, the second pressure plate 582, and the third pressure plate 583 are all elastic pressure plates.

[0048] A fine-tuning base 50 is located at the end of the base plate 1 away from the hand crank 7. A fine-tuning base plate 51 is fixedly mounted on the fine-tuning base 50. A Y-axis rotating plate 52 is arranged on the fine-tuning base plate 51 along the X-axis direction. The fine-tuning base plate 51 acts as a Y-axis linkage plate. One side of the fine-tuning base plate 51 is hinged to the side opposite to the Y-axis rotating plate 52 via a first rotating shaft 561. The first rotating shaft 561 is arranged along the Y-axis direction. A first slot 51 is located on the side of the fine-tuning base plate 51 away from the first rotating shaft 561. 1. One end of the first pressure plate 581 is fixedly mounted on the first slot 511, and the other end of the first pressure plate 581 is positioned above the Y-axis rotating plate 52. The first spherical differential switch 591 is positioned above the first pressure plate 581, and the telescopic rod of the first spherical differential switch 591 passes through the first pressure plate 581 and abuts against the Y-axis rotating plate 52. One end of the first compression spring abuts against the fine-tuning base plate 51, and the other end of the first compression spring abuts against the Y-axis rotating plate 52. The first spherical differential switch 591 is used to adjust the gap between the Y-axis rotating plate 52 and the fine-tuning base plate 51. By adjusting the first spherical differential switch 591, the Y-axis rotating plate 52 moves away from / closes to the fine-tuning base plate 51 around the first rotating axis 561, thereby adjusting the illumination direction of the light source 3 in the Y-axis direction.

[0049] The Y-axis rotating plate 52 has an X-axis rotating plate 55 arranged along the Y-axis direction. The Y-axis rotating plate 52 acts as an X-axis linkage plate. One side of the Y-axis rotating plate 52 is hinged to the opposite side of the X-axis rotating plate 55 via a second rotating shaft, which is arranged along the X-axis direction. A second slot 521 is located on the side of the Y-axis rotating plate 52 away from the second rotating shaft. One end of a second pressure plate 582 is fixedly mounted in the second slot 521, and the other end of the second pressure plate 582 is positioned above the X-axis rotating plate 55. A second spherical differential switch 592 is positioned above the second pressure plate 582, and its telescopic rod passes through the second pressure plate 582 and abuts against the X-axis rotating plate 55. One end of a second compression spring abuts against the Y-axis rotating plate 52, and the other end of the second compression spring abuts against the X-axis rotating plate 55. The second spherical differential switch 592 is used to adjust the gap between the Y-axis rotating plate 52 and the X-axis rotating plate 55. By adjusting the second spherical differential switch 592, the X-axis rotating plate 55 is moved away from / closer to the Y-axis rotating plate 52 around the second rotating axis, thereby adjusting the illumination direction of the light source 3 in the X-axis direction.

[0050] The Z-axis linkage plate 54 is vertically mounted on the X-axis rotating plate 55. A Z-axis rotating plate 53 is mounted on one side of the Z-axis linkage plate 54. The Z-axis linkage plate 54 is vertically positioned, and its opposite side is hinged to the Z-axis rotating plate 53 via a third rotating shaft 563, which is positioned along the Z-axis. A third slot 541 is located on the side of the Z-axis linkage plate 54 away from the third rotating shaft 563. One end of a third pressure plate 583 is fixedly mounted in the third slot 523, and the other end is located on the side of the Z-axis rotating plate 53 away from the Z-axis linkage plate 54. A third spherical differential switch 593 is located on the side of the third pressure plate 583 away from the Z-axis rotating plate 53. One end of a third compression spring abuts against the X-axis rotating plate 55, and the other end abuts against the Z-axis linkage plate 54. The third spherical differential switch 593 is used to adjust the gap between the Z-axis linkage plate 54 and the Z-axis rotating plate 53. By adjusting the third spherical differential switch 593, the Z-axis rotating plate 53 is moved away from / closer to the Z-axis linkage plate 54 around the third rotating axis 563, thereby adjusting the illumination direction of the light source 3 in the Z-axis direction.

[0051] The three-axis fine-tuning device 5 of the present invention has a simple structure and compact design. By adjusting the Y-axis rotating plate 52, the Z-axis rotating plate 53 and the X-axis rotating plate 55, the three-dimensional position of the light source 3 can be fine-tuned, which is convenient, flexible and has high adjustment accuracy. At the same time, by fine-tuning the position of the light source 3, the distance error between the camera 4 and the calibration block 2 can be effectively reduced, and the calibration accuracy of the camera 4 can be improved.

[0052] Furthermore, the three-axis fine-tuning device 5 is provided with a housing 6 for placing the light source 3 and the camera 4. The housing 6 is a hollow housing, and the inner cavity of the housing 6 is provided with a accommodating space 61 for placing the light source 3 and the camera 4. The light source 3 is positioned above the camera 4.

[0053] The camera 4 used in this invention is a laser scanning camera. The camera 4 is mounted on the accommodating space 61. A light-shielding sleeve 62 is also installed inside the housing 6 to prevent light leakage. A lens 63 is mounted at the front end of the light-shielding sleeve 62, and a filter (not shown in the figure) is mounted at the front end of the lens 63 to filter light beams of different wavelengths other than laser light. The camera 4 is at a certain angle to the light beam emitted by the light source 3. A transparent glass 64 is mounted on the outer shell of the housing 6. A sealing ring (not shown in the figure) is installed between the transparent glass 64 and the outer shell of the camera 4 to prevent dust from entering the interior of the camera 4. An O-ring groove (not shown in the figure) is also provided between the outer shell of the camera 4 and the accommodating space 61. The entire assembly achieves an IP67 sealing performance.

[0054] The advantages of the present invention using the above technical solution are as follows: The calibration device of the present invention is equipped with a series of staggered calibration tips. It can acquire the data of all pixels with only one image and without the need for other auxiliary moving platforms. The calibration device of the present invention has high calibration accuracy, fast calibration efficiency, and is easy to use. When the light source 3 emits a beam, the three-axis fine adjustment device 5 is adjusted so that the beam of the light source 3 illuminates the calibration tips of all calibration units 22 of the calibration plate 2, calibrating the relative position of the camera 4 and the calibration plate 2. The data information of the calibration plate 2 can be acquired quickly and accurately, and then transmitted to the computer for reading and conversion. This has a significant effect on improving the efficiency and accuracy of batch camera calibration.

[0055] This invention also provides a calibration method for a line laser camera, the specific operation steps of which are as follows:

[0056] S1: Install the camera 4 to be calibrated. Install the 3D scanning camera 4 to be calibrated on the housing 6 of the three-axis fine-tuning device 5 in the accommodating space 61 and tighten it with screws.

[0057] S2: Adjust the laser plane of the light source 3. By adjusting the three-axis fine adjustment device 5, adjust the rotation angle of the Y-axis rotating plate 52, Z-axis rotating plate 53 and X-axis rotating plate 55 so that the laser beam of the light source 3 irradiates the groove 231 of the calibration plate 2 and penetrates the groove 231, that is, let the laser beam of the light source 3 descend and irradiate the calibration tips of each calibration unit 22 to determine whether the laser plane of the light source 3 coincides with the plane of all calibration tips on the calibration plate 2.

[0058] S3: Create a visual matching template in advance so that the camera 4 can acquire the data of all pixels. Set the cusp of any calibration unit 22 as the reference origin (0,0). Since the physical quantities of the calibration plate 2 are known, the coordinates of the cusps of other calibration units 22 (X1,Y1), (X2,Y2)...(Xn,Yn) can be calculated.

[0059] S4: Start the software of camera 4, and begin to acquire the pixel positions (A1,B1), (A2,B2)...(An,Bn) of all cusps in each calibration unit 22 within the camera's field of view. Perform a matrix transformation algorithm with all the actual cusp data to calculate the parameters inside the camera, i.e., the calibration completion conversion equation.

[0060] Conversion equation: (taking 4 points as an example)

[0061] The physical point coordinates of calibration unit 22 on actual calibration board 2 are: (X1,Y1), (X2,Y2), (X3,Y3), (X4,Y4).

[0062] The pixel coordinates corresponding to the cusp in the camera software are: (A1, B1), (A2, B2), (A3, B3), (A4, B4).

[0063] Based on the above, establish a system of equations.

[0064] X1=HA1+IB1+J-KX1A1-LA1Y1

[0065] Y1=MA1+NB1+O-KY1A1-LB1Y1

[0066] X2=HA2+IB2+J-KX2A2-LA2Y2

[0067] Y2=MA2+NB2+O-KY2A2-LB2Y2

[0068] X3=HA3+IB3+J-KX3A3-LA3Y3

[0069] Y3=MA3+NB3+O-KY3A3-LB3Y3

[0070] X4 = HA4 + IB4 + J - KX4A4 - LA4Y4

[0071] Y4 = MA4 + NB4 + O-KY4A4-LB4Y4

[0072] Finally, calculate the values ​​of H, I, J, K, L, M, N, and O.

[0073]

[0074] Solve for the values ​​of H, I, J, K, L, M, N, O.

[0075] After conversion, the coordinate conversion between the actual physical coordinate values ​​on the reference surface and the pixel values ​​in the camera software was determined.

[0076] The advantages of this invention using the above technical solution are: the calibration device of this invention sets a series of staggered calibration cusps, requiring only one image and no other auxiliary moving platform to acquire data for all pixels. The calibration device of this invention has high calibration accuracy, fast calibration efficiency, and is easy to use. When the light source 3 emits a beam, the three-axis fine-tuning device 5 is adjusted so that the beam of the light source 3 evenly illuminates all calibration cusps on the calibration plate 2 in the horizontal direction, calibrating the relative position of the camera 4 and the calibration plate 2. This allows for quick and accurate acquisition of data information from the calibration plate 2, which is then transmitted to a computer for reading and calculation. This significantly improves the efficiency and accuracy of batch camera calibration. This invention provides a cusp-type staggered calibration method. Based on the camera's field of view, this invention sets a series of staggered calibration units 22, requiring only one image and no other auxiliary moving platform to acquire data for all pixels, perform matrix transformation calculations, obtain the relevant internal parameters of the camera, and complete the calibration.

[0077] The present invention has been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the above embodiments. Those skilled in the art can make various modifications to the present invention based on the prior art, and these modifications all fall within the protection scope of the present invention.

Claims

1. A calibration device for a line laser camera, characterized in that: It comprises a workbench, a calibration plate, a light source for emitting a light beam, and a three-axis fine-tuning device for adjusting the irradiation direction of the light source, wherein the calibration plate is arranged on the workbench, the workbench is arranged on one side of the three-axis fine-tuning device, the light source is arranged on the three-axis fine-tuning device, a plurality of calibration groups are evenly arranged on the calibration plate, two adjacent calibration groups are arranged in parallel and equidistantly, each calibration group comprises a plurality of calibration units arranged equidistantly and at intervals, the calibration unit has a calibration point, the calibration points of the plurality of calibration units of each calibration group are staggered, each calibration unit extends upward, a step is arranged at the edge of the calibration plate, the step has a L-shaped groove in the horizontal direction, the groove runs from one side of the step to the other side of the step, the groove is arranged in the horizontal direction, and the groove is at the same height as the calibration point of each calibration unit; Define the arrangement direction of each calibration group as the Y axis, the arrangement direction horizontally perpendicular to each calibration group as the X axis, and the arrangement direction vertically perpendicular to each calibration group as the Z axis; The three-axis fine-tuning device is arranged on the bottom plate, and the three-axis fine-tuning device includes a fine-tuning bottom plate, a Y-axis rotating plate, a Z-axis rotating plate, a Z-axis linkage plate, an X-axis rotating plate, a first rotating shaft, a second rotating shaft, a third rotating shaft, a first compression spring, a second compression spring, a third compression spring, a first pressing plate, a second pressing plate, a third pressing plate, a first spherical differential switch for adjusting the gap between the Y-axis rotating plate and the fine-tuning bottom plate, a second spherical differential switch for adjusting the gap between the Y-axis rotating plate and the X-axis rotating plate, and a third spherical differential switch for adjusting the gap between the X-axis rotating plate and the Z-axis rotating plate; The fine-tuning base plate is provided with the Y-axis rotating plate along the direction of the X-axis, one side of the fine-tuning base plate is hinged to the side opposite to the Y-axis rotating plate through the first rotating shaft, the first rotating shaft is provided along the Y-axis direction, the first pressing plate is provided on the side of the fine-tuning base plate away from the first rotating shaft, one end of the first pressing plate is fixedly provided on the fine-tuning base plate, the first pressing plate extends to the top of the Y-axis rotating plate, the first spherical differential switch is provided above the first pressing plate, and the telescopic rod of the first spherical differential switch passes through the first pressing plate and abuts against the Y-axis rotating plate, one end of the first compression spring abuts against the fine-tuning base plate, and the other end of the first compression spring abuts against the shaft rotating plate; The Y-axis rotating plate is provided with the X-axis rotating plate along the direction of the Z-axis, one side of the Y-axis rotating plate is hinged to the side opposite to the X-axis rotating plate through the second rotating shaft, the second rotating shaft is provided along the X-axis direction, the second pressure plate is provided on the side of the Y-axis rotating plate away from the second rotating shaft, one end of the second pressure plate is fixedly provided on the Y-axis rotating plate, the second pressure plate extends to the top of the X-axis rotating plate, the second spherical differential switch is provided above the second pressure plate, and the telescopic rod of the second spherical differential switch passes through the second pressure plate and abuts against the X-axis rotating plate, one end of the second compression spring abuts against the Y-axis rotating plate, and the other end of the second compression spring abuts against the X-axis rotating plate; The Z-axis linkage plate is vertically arranged on the X-axis rotating plate, and the Z-axis rotating plate is arranged on one side of the Z-axis linkage plate. The Z-axis linkage plate is arranged in the vertical direction, and one side of the Z-axis linkage plate is hinged to the side opposite to the Z-axis rotating plate through the third rotating shaft, and the third rotating shaft is arranged along the Z-axis direction, and the third pressure plate is arranged on the side of the Z-axis linkage plate away from the third rotating shaft, one end of the third pressure plate is fixedly arranged on the Z-axis linkage plate, and the third pressure plate extends to the top of the Z-axis rotating plate, the third spherical differential switch is arranged above the third pressure plate, and the telescopic rod of the third spherical differential switch passes through the third pressure plate and abuts on the Z-axis rotating plate, one end of the third compression spring abuts on the X-axis rotating plate, and the other end of the third compression spring abuts on the Z-axis linkage plate.

2. The calibration device for a line laser camera according to claim 1, characterized in that: The three-axis fine-tuning device is provided with a shell for placing the light source and the camera. The shell is a hollow shell, and the inner cavity of the shell is provided with a accommodating space for placing the light source and the camera. The light source is arranged above the camera.

3. The calibration device for a line laser camera according to claim 1, characterized in that: The light source includes at least one of a light emitting diode and a laser light source.

4. A calibration method using the calibration device of a line laser camera according to claim 1, characterized in that: The steps include: S1: Install the camera to be calibrated on the three-axis fine-tuning device; S2: adjusting the laser plane of the light source, by adjusting the three-axis fine-tuning device, allowing the laser beam of the light source to irradiate the groove of the calibration plate, that is, allowing the laser beam of the light source to descend and irradiate the calibration sharp points of each calibration unit, to determine whether the laser plane of the light source coincides with all the calibration sharp point planes of the calibration plate; S3: Pre-create a visual matching template so that the camera can obtain data of all pixel points, set the calibration point of any calibration unit as the reference origin (0,0), and calculate the calibration point coordinates of other calibration units (X1, Y1), (X2, Y2)...(Xn, Yn); S4: Start the camera software and start to obtain the pixel positions (A1, B1), (A2, B2)... (An, Bn) of all the calibration points of each calibration unit within the camera field of view, and perform a matrix conversion algorithm with the actual calibrated calibration point data to calculate the internal parameters of the camera, that is, the calibration completion conversion equation.

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