A calibration method for a fixed line laser camera

Abstract

The present invention discloses a calibration method for a fixed line laser camera, and relates to the technical field of line laser measurement. The present invention comprises the following steps: S1, setting a high-precision calibration block; S2, taking a picture with a line laser camera to obtain a 3D point cloud contour line, and the contour line forms a plurality of breakpoints on the calibration block; S201, the breakpoints are recorded as: P1, P2, P3, P4, P5, P6, P7, P8; S3, implementation of the calibration method. The present invention adopts a mechanical structure of a high-precision boss to develop a method capable of quickly calibrating a 3D single-line laser camera; the advantages of the calibration method are: being able to quickly and accurately obtain the conversion matrix of the 3D single-line laser camera coordinate system relative to the reference coordinate system; it can be used as the first calibration for the initial installation of the camera, and can also be used as a rapid recovery calibration after the camera is replaced, which greatly improves the efficiency and operation difficulty of on-site debugging, and effectively reduces the loss caused by downtime.

Description

Technical Field

[0001] The invention belongs to the technical field of line laser measurement, and in particular relates to a calibration method for a fixed line laser camera. Background Art

[0002] For 3D line laser profile sensors (3D single-line laser cameras), the working principle is that a single laser line can obtain X and Z information of the object surface through triangulation. Most single-line laser camera applications on the market are concentrated in scanning situations, focusing on the relative size and position of single-line profile images and using point cloud information for defect detection. These applications often do not pay attention to the conversion relationship between the camera coordinate system and the external reference coordinate system. Camera calibration is often not required. Even if it is required, it can only be calibrated for some degrees of freedom through some specific blocks. For the occasions of synchronous measurement of multiple 3D line laser profile sensors, each camera has a unified coordinate system, and it is a 6-degree-of-freedom coordinate system conversion and fast calibration. There is a lack of a reliable and fast calibration algorithm. Therefore, a calibration method for fixed line laser cameras is proposed. Summary of the invention

[0003] The purpose of the present invention is to provide a calibration method for a fixed line laser camera to solve the existing problems.

[0004] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0005] The present invention is a calibration method for a fixed line laser camera, comprising the following steps:

[0006] S1. Set a high-precision calibration block and measure the position of each plane on the calibration block through an external device to construct a calibration block coordinate system;

[0007] S2, using a line laser camera to take a picture to obtain a 3D point cloud contour line, and the contour line forms multiple breakpoints on the calibration block;

[0008] S201, the breakpoints are recorded as: P1, P2, P3, P4, P5, P6, P7, P8;

[0009] S3, implementation of calibration method;

[0010] S301, obtaining the data of each plane of the calibration block;

[0011] S302, obtaining a transformation matrix according to the rotation order of Rx, Ry, and Rz;

[0012] The rotation of Rx is the rotation of the laser plane, which can be obtained through the actual distance DH between P2-P3 and P6-P7 and the height H of the standard block:

[0013] Rx = ±arccos(H / DH);

[0014] Where: Rx represents the rotation angle around the X-axis of the reference coordinate system of the calibration block;

[0015] The matrix constructed according to Rx is RotX:

[0016] ;

[0017] Where: RotX is the rotation matrix formed by rotating the camera around the reference coordinate system of the calibration block by an angle of Rx;

[0018] Using the point cloud between P3-P4 and P5-P6, a space straight line is constructed, and the expression is expressed as:

[0019] ;

[0020] Where: Zc represents the Z direction of each point cloud coordinate in the camera coordinate system; Xc represents the X direction of each point cloud coordinate in the camera coordinate system; k is the slope of the straight line; b is the intercept of the straight line;

[0021] Since this straight line is on the plane of the calibration block Z=0, the angle corresponding to the slope k in the above formula is Ry, so:

[0022] Ry=arctan(k);

[0023] Where: Ry represents the rotation angle around the Y axis of the calibration block reference coordinate system;

[0024] At this time, the transformation matrix RotY formed by Ry is:

[0025] ;

[0026] Where: RotY is the rotation matrix formed by rotating the camera around the calibration block reference coordinate system by an angle of Ry;

[0027] Using the distance DL between the measured values ​​of points P3 and P6 and the length L of the standard block, Rz can be obtained;

[0028] Rz=±arccos(L / DL)

[0029] Where: Rz represents the rotation angle around the Z axis of the calibration block reference coordinate system;

[0030] Construct the rotation matrix RotZ according to Rz:

[0031] ;

[0032] Where: RotZ is the rotation matrix formed by rotating the camera around the reference coordinate system of the calibration block by an angle of Rz;

[0033] The rotation is around the X\Y\Z axis, that is, the ZYX sequential rotation matrix method:

[0034] ;

[0035] Where: Rot represents the rotation transformation matrix of the camera coordinate system relative to the calibration block coordinate system;

[0036] S303, calculating the translation amount T;

[0037] Starting from the Z direction, the average is calculated based on the point clouds between P3-P4 and P5-P6, because these point clouds are at the position Z=0 in the calibration block coordinate system; therefore,

[0038] ;

[0039] ;

[0040] ;

[0041] Where: Ptcloud_Cam is the point cloud in the camera coordinate system;

[0042] Ptcloud_Base is the point cloud in the calibration block coordinate system;

[0043] Ptcloud_Base[Z] is the Z coordinate value of these points;

[0044] Tz is the Z-direction translation of the camera coordinate system relative to the calibration block coordinate system;

[0045] Then the X-axis translation, Tx, is calculated based on the average of points P3 and P6; where P3 is at X=0 and P6 is at X=L;

[0046] ;

[0047] ;

[0048] ;

[0049] Where: Tx is the X-axis translation of the camera coordinate system relative to the calibration block coordinate system;

[0050] Rot represents the rotation transformation matrix of the camera coordinate system relative to the calibration block coordinate system;

[0051] P3_Base is the position of point P3 in the calibration block coordinate system;

[0052] P6_Base is the position of point P6 in the calibration block coordinate system;

[0053] P3_Base[X] is the X coordinate value of point P3 in the calibration block coordinate system;

[0054] P6_Base[X] is the X coordinate value of point P6 in the calibration block coordinate system;

[0055] L is the side length of the calibration block;

[0056] Finally, the Y translation Ty can be obtained based on point P4. Since point P4 is on the hypotenuse, the equation of the straight line of the hypotenuse is as follows according to the design:

[0057] ;

[0058] Where: x and y are the coordinate values ​​of the point on the hypotenuse in the X and Y axis directions in the calibration block coordinate system;

[0059] Transform P4 in the camera coordinate system to the calibration block coordinate system by rotation:

[0060] ;

[0061] Where: P4_Base is the point position of point P4 in the camera coordinate system after ROT rotation transformation in the calibration block coordinate system;

[0062] then:

[0063] ;

[0064] Where: P4_Base[X] represents the X value of the coordinate point;

[0065] P4_Base[Y] represents the Y value of the coordinate point;

[0066] Ty is the X-direction translation of the camera coordinate system relative to the calibration block coordinate system;

[0067] The translation matrix T is:

[0068] ;

[0069] Where: T is the translation of the origin of the camera coordinate system relative to the origin of the calibration block coordinate system;

[0070] Tx is the X-axis translation of the camera coordinate system relative to the calibration block coordinate system;

[0071] Ty is the Y-axis translation of the camera coordinate system relative to the calibration block coordinate system;

[0072] Tz is the Z-direction translation of the camera coordinate system relative to the calibration block coordinate system;

[0073] S304, finally the comprehensive transformation matrix of the camera relative to the calibration block coordinate system is:

[0074] ;

[0075] Where: M is the transformation matrix of the camera coordinate system relative to the calibration block coordinate system.

[0076] Furthermore, in step S1, the calibration block includes a boss, a mounting plate is fixed to the lower surface of the boss, the boss is fixed to the middle of the upper surface of the mounting plate, a surface of the mounting plate is provided with a plurality of mounting holes, a groove is provided on the upper surface of the boss, one side of the groove is a diagonal side, and positioning pins are symmetrically provided on the upper surface of the boss.

[0077] Furthermore, the positioning pins are given by design and are used to reversely construct the calibration block coordinate system.

[0078] Furthermore, the boss is a cubic structure, the side length of the square on the upper surface of the boss needs to be greater than half of the effective length of the camera laser line, and the height of the boss is greater than half of the longitudinal depth of the camera.

[0079] Furthermore, the groove is designed to accurately capture points on the hypotenuse in the camera image, and use these data to calculate the Y-direction position of the laser line in the calibration block coordinate system.

[0080] The present invention has the following beneficial effects:

[0081] The present invention adopts a mechanical structure of a high-precision boss to develop a method for quickly calibrating a 3D single-line laser camera. The advantages of the calibration method are: it can quickly and accurately obtain the transformation matrix of the 3D single-line laser camera coordinate system relative to the reference coordinate system; it can be used as the first calibration of the camera when it is first installed, and it can also be used as a fast recovery calibration after the camera is replaced, which greatly improves the efficiency and operation difficulty of on-site debugging and effectively reduces the loss caused by downtime.

[0082] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0084] Figure 1 is a flow chart of a calibration method for a fixed line laser camera;

[0085] Figure 2 It is a schematic diagram of the 3D point cloud contour line of the present invention;

[0086] Figure 3 A schematic diagram of a coordinate system for constructing a calibration block in the present invention;

[0087] Figure 4 It is a schematic diagram of the overall structure of the calibration block in the present invention.

[0088] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0089] 1. Boss; 2. Mounting plate; 3. Positioning pin; 4. Groove. DETAILED DESCRIPTION

[0090] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0091] In the description of the present invention, it should be understood that the terms "upper", "middle", "outer", "inner" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0092] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0093] See also Figure 1-Figure 3 As shown, the present invention is a calibration method for a fixed line laser camera, comprising the following steps:

[0094] S1. Set a high-precision calibration block and measure the position of each plane on the calibration block through an external device to construct a calibration block coordinate system;

[0095] S2, using a line laser camera to take a picture to obtain a 3D point cloud contour line, and the contour line forms multiple breakpoints on the calibration block;

[0096] S201, the breakpoints are recorded as: P1, P2, P3, P4, P5, P6, P7, P8;

[0097] S3, implementation of calibration method;

[0098] S301, obtaining the data of each plane of the calibration block;

[0099] S302, obtaining a transformation matrix according to the rotation order of Rx, Ry, and Rz;

[0100] The rotation of Rx is the rotation of the laser plane, which can be obtained through the actual distance DH between P2-P3 and P6-P7 and the height H of the standard block:

[0101] Rx = ±arccos(H / DH);

[0102] Where: Rx represents the rotation angle around the X-axis of the reference coordinate system of the calibration block;

[0103] The matrix constructed according to Rx is RotX:

[0104] ;

[0105] Where: RotX is the rotation matrix formed by rotating the camera around the reference coordinate system of the calibration block by an angle of Rx;

[0106] Using the point cloud between P3-P4 and P5-P6, a space straight line is constructed, and the expression is expressed as:

[0107] ;

[0108] Where: Zc represents the Z direction of each point cloud coordinate in the camera coordinate system; Xc represents the X direction of each point cloud coordinate in the camera coordinate system; k is the slope of the straight line; b is the intercept of the straight line;

[0109] Since this straight line is on the plane of the calibration block Z=0, the angle corresponding to the slope k in the above formula is Ry, so:

[0110] Ry=arctan(k);

[0111] Where: Ry represents the rotation angle around the Y axis of the calibration block reference coordinate system;

[0112] At this time, the transformation matrix RotY formed by Ry is:

[0113] ;

[0114] Where: RotY is the rotation matrix formed by rotating the camera around the calibration block reference coordinate system by an angle of Ry;

[0115] Using the distance DL between the measured values ​​of points P3 and P6 and the length L of the standard block, Rz can be obtained;

[0116] Rz=±arccos(L / DL)

[0117] Where: Rz represents the rotation angle around the Z axis of the calibration block reference coordinate system;

[0118] Construct the rotation matrix RotZ according to Rz:

[0119] ;

[0120] Where: RotZ is the rotation matrix formed by rotating the camera around the reference coordinate system of the calibration block by an angle of Rz;

[0121] The rotation is around the X\Y\Z axis, that is, the ZYX sequential rotation matrix method:

[0122] ;

[0123] Where: Rot represents the rotation transformation matrix of the camera coordinate system relative to the calibration block coordinate system;

[0124] S303, calculating the translation amount T;

[0125] Starting from the Z direction, the average is calculated based on the point clouds between P3-P4 and P5-P6, because these point clouds are at the position Z=0 in the calibration block coordinate system; therefore,

[0126] ;

[0127] ;

[0128] ;

[0129] Where: Ptcloud_Cam is the point cloud in the camera coordinate system;

[0130] Ptcloud_Base is the point cloud in the calibration block coordinate system;

[0131] Ptcloud_Base[Z] is the Z coordinate value of these points;

[0132] Tz is the Z-direction translation of the camera coordinate system relative to the calibration block coordinate system;

[0133] Then the X-axis translation, Tx, is calculated based on the average of points P3 and P6; where P3 is at X=0 and P6 is at X=L;

[0134] ;

[0135] ;

[0136] ;

[0137] Where: Tx is the X-axis translation of the camera coordinate system relative to the calibration block coordinate system;

[0138] Rot represents the rotation transformation matrix of the camera coordinate system relative to the calibration block coordinate system;

[0139] P3_Base is the position of point P3 in the calibration block coordinate system;

[0140] P6_Base is the position of point P6 in the calibration block coordinate system;

[0141] P3_Base[X] is the X coordinate value of point P3 in the calibration block coordinate system;

[0142] P6_Base[X] is the X coordinate value of point P6 in the calibration block coordinate system;

[0143] L is the side length of the calibration block;

[0144] Finally, the Y translation Ty can be obtained based on point P4. Since point P4 is on the hypotenuse, the equation of the straight line of the hypotenuse is as follows according to the design:

[0145] ;

[0146] Where: x and y are the coordinate values ​​of the point on the hypotenuse in the X and Y axis directions in the calibration block coordinate system;

[0147] Transform P4 in the camera coordinate system to the calibration block coordinate system by rotation:

[0148] ;

[0149] Where: P4_Base is the point position of point P4 in the camera coordinate system after ROT rotation transformation in the calibration block coordinate system;

[0150] then:

[0151] ;

[0152] Where: P4_Base[X] represents the X value of the coordinate point;

[0153] P4_Base[Y] represents the Y value of the coordinate point;

[0154] Ty is the X-direction translation of the camera coordinate system relative to the calibration block coordinate system;

[0155] The translation matrix T is:

[0156] ;

[0157] Where: T is the translation of the origin of the camera coordinate system relative to the origin of the calibration block coordinate system;

[0158] Tx is the X-axis translation of the camera coordinate system relative to the calibration block coordinate system;

[0159] Ty is the Y-axis translation of the camera coordinate system relative to the calibration block coordinate system;

[0160] Tz is the Z-direction translation of the camera coordinate system relative to the calibration block coordinate system;

[0161] S304, finally the comprehensive transformation matrix of the camera relative to the calibration block coordinate system is:

[0162] ;

[0163] Where: M is the transformation matrix of the camera coordinate system relative to the calibration block coordinate system.

[0164] Among them, the calibration block in step S1 includes a boss 1, a mounting plate is fixed on the lower surface of the boss 1, the boss 1 is fixed to the middle of the upper surface of the mounting plate 2, a surface of the mounting plate 2 is provided with a plurality of mounting holes, a groove 4 is provided on the upper surface of the boss 1, one side of the groove 4 is a diagonal side, and a positioning pin 3 is symmetrically provided on the center of the upper surface of the boss 1.

[0165] Among them, the positioning pin 3 is given by design and is used to reversely construct the calibration block coordinate system.

[0166] The boss 1 is a cubic structure, and the side length of the square on the upper surface of the boss 1 is greater than half of the effective length of the camera laser line; the height of the boss 1 is greater than half of the longitudinal depth of the camera.

[0167] The design of groove 4 is used to accurately capture the points on the hypotenuse in the camera image, and use these data to calculate the position of the laser line in the Y direction in the calibration block coordinate system.

[0168] It needs further explanation:

[0169] The calibration block is generally designed in the form of a square boss 1 plus a bottom mounting plate 2. The bottom mounting plate 2 is designed to facilitate installation and fixation, and also serves as a reference ground for measuring the height of the boss 1.

[0170] The calibration block boss 1 is designed in the form of a cube in order to facilitate the subsequent acquisition of algorithm parameter values; for example, the construction of the side length L and the hypotenuse equation.

[0171] The design of the square plane is also considered from a processing perspective. The milling of the plane is easier to ensure the accuracy of the plane, including flatness, verticality and distance between the planes.

[0172] Two locating pin holes are designed on the calibration block, and two locating pins 3 can be installed; the positions of these two locating pin holes are given by design and can be used to reversely construct the calibration block coordinate system.

[0173] The side length of the calibration block boss 1 can be scalable and designed according to the size of the camera laser line and the field of view. Usually, the square side length of the calibration block boss 1 needs to be greater than half of the effective length of the camera laser line.

[0174] The height of the calibration block boss 1 also needs to be determined based on the camera's depth direction (Z direction) field of view. Usually, the height of the calibration block boss 1 needs to be greater than half of the camera's longitudinal depth.

[0175] A groove 4 is designed on the top surface of the calibration block to process a diagonal edge, which can easily and quickly construct the straight line equation of the hypotenuse. At the same time, the design of the groove 4 is also convenient for accurately capturing the points on the hypotenuse in the camera image, and using these data to calculate the Y direction position of the laser line in the calibration block coordinate system.

[0176] This calibration block is closely linked to the subsequent algorithm, and the parameters used in the algorithm design are all based on the calibration block of this design form.

[0177] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0178] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A calibration method for a fixed line laser camera, characterized in that: The following steps are involved: S1. Set a high-precision calibration block and measure the position of each plane on the calibration block through an external device to construct a calibration block coordinate system; S2, using a line laser camera to take a picture to obtain a 3D point cloud contour line, and the contour line forms multiple breakpoints on the calibration block; S201, the breakpoints are recorded as: P1, P2, P3, P4, P5, P6, P7, P8; S3, implementation of calibration method; S301, obtaining the data of each plane of the calibration block; S302, obtaining a transformation matrix according to the rotation order of Rx, Ry, and Rz; The rotation of Rx is the rotation of the laser plane, which can be obtained through the actual distance DH between P2-P3 and P6-P7 and the height H of the standard block: Rx = ±arccos(H / DH); Where: Rx represents the rotation angle around the X-axis of the reference coordinate system of the calibration block; The matrix constructed according to Rx is RotX: ； Where: RotX is the rotation matrix formed by rotating the camera around the reference coordinate system of the calibration block by an angle of Rx; Using the point cloud between P3-P4 and P5-P6, a space straight line is constructed, and the expression is expressed as: ； Where: Zc represents the Z direction of each point cloud coordinate in the camera coordinate system; Xc represents the X direction of each point cloud coordinate in the camera coordinate system; k is the slope of the straight line; b is the intercept of the straight line; Since this straight line is on the plane of the calibration block Z=0, the angle corresponding to the slope k in the above formula is Ry, so: Ry=arctan(k); Where: Ry represents the rotation angle around the Y axis of the calibration block reference coordinate system; At this time, the transformation matrix RotY formed by Ry is: ； Where: RotY is the rotation matrix formed by rotating the camera around the calibration block reference coordinate system by an angle of Ry; Using the distance DL between the measured values ​​of points P3 and P6 and the length L of the standard block, Rz can be obtained; Rz=±arccos(L / DL) Where: Rz represents the rotation angle around the Z axis of the calibration block reference coordinate system; Construct the rotation matrix RotZ according to Rz: ； Where: RotZ is the rotation matrix formed by rotating the camera around the reference coordinate system of the calibration block by an angle of Rz; The rotation is around the X\Y\Z axis, that is, the ZYX sequential rotation matrix method: ； Where: Rot represents the rotation transformation matrix of the camera coordinate system relative to the calibration block coordinate system; S303, calculating the translation amount T; Starting from the Z direction, the average is calculated based on the point clouds between P3-P4 and P5-P6, because these point clouds are at the position Z=0 in the calibration block coordinate system; therefore, ； ； ； Where: Ptcloud_Cam is the point cloud in the camera coordinate system; Ptcloud_Base is the point cloud in the calibration block coordinate system; Ptcloud_Base[Z] is the Z coordinate value of these points; Tz is the Z-direction translation of the camera coordinate system relative to the calibration block coordinate system; Then the X-axis translation, Tx, is calculated based on the average of points P3 and P6; where P3 is at X=0 and P6 is at X=L; ； ； ； Where: Tx is the X-axis translation of the camera coordinate system relative to the calibration block coordinate system; Rot represents the rotation transformation matrix of the camera coordinate system relative to the calibration block coordinate system; P3_Base is the position of point P3 in the calibration block coordinate system; P6_Base is the position of point P6 in the calibration block coordinate system; P3_Base[X] is the X coordinate value of point P3 in the calibration block coordinate system; P6_Base[X] is the X coordinate value of point P6 in the calibration block coordinate system; L is the side length of the calibration block; Finally, the Y translation Ty can be obtained based on point P4. Since point P4 is on the hypotenuse, the equation of the straight line of the hypotenuse is as follows according to the design: ； Where: x and y are the coordinate values ​​of the point on the hypotenuse in the X and Y axis directions in the calibration block coordinate system; Transform P4 in the camera coordinate system to the calibration block coordinate system by rotation: ； Where: P4_Base is the point position of point P4 in the camera coordinate system after ROT rotation transformation in the calibration block coordinate system; then: ； Where: P4_Base[X] represents the X value of the coordinate point; P4_Base[Y] represents the Y value of the coordinate point; Ty is the X-direction translation of the camera coordinate system relative to the calibration block coordinate system; The translation matrix T is: ； Where: T is the translation of the origin of the camera coordinate system relative to the origin of the calibration block coordinate system; Tx is the X-axis translation of the camera coordinate system relative to the calibration block coordinate system; Ty is the Y-axis translation of the camera coordinate system relative to the calibration block coordinate system; Tz is the Z-direction translation of the camera coordinate system relative to the calibration block coordinate system; S304, finally the comprehensive transformation matrix of the camera relative to the calibration block coordinate system is: ； Where: M is the transformation matrix of the camera coordinate system relative to the calibration block coordinate system.

2. The calibration method of a fixed line laser camera according to claim 1, characterized in that: In step S1, the calibration block comprises a boss (1), a mounting plate (2) is fixed to the lower surface of the boss (1), the boss (1) is fixed to the middle of the upper surface of the mounting plate (2), a surface of the mounting plate (2) is provided with a plurality of mounting holes, a groove (4) is provided on the upper surface of the boss (1), one side of the groove (4) is a diagonal side, and positioning pins (3) are symmetrically provided on the center of the upper surface of the boss (1).

3. The calibration method of a fixed line laser camera according to claim 2, characterized in that: The positioning pin (3) is given by design and is used to reversely construct the calibration block coordinate system.

4. The method for calibrating a fixed line laser camera according to claim 2, characterized in that: The boss (1) is a cubic structure, the side length of the square on the upper surface of the boss (1) needs to be greater than half the effective length of the camera laser line, and the height of the boss (1) is greater than half the longitudinal depth of the camera.

5. The method for calibrating a fixed line laser camera according to claim 2, characterized in that: The groove (4) is designed to accurately capture points on the hypotenuse in the camera image, and use these data to calculate the position of the laser line in the Y direction in the calibration block coordinate system.

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