Coordinate system calibration method of three-dimensional line scanning system and three-dimensional calibration block

Abstract

The embodiment of the invention discloses a coordinate system calibration method of a three-dimensional line scanning system and a three-dimensional calibration block. The three-dimensional line scanning system comprises a three-dimensional line scanning module and an operation control platform, the three-dimensional calibration block is provided with at least three calibration planes which are intersected pairwise, and intersecting lines of every two intersected calibration planes in the at least three calibration planes are parallel to each other; the method comprises the following steps: acquiring at least one group of point cloud data acquired when a three-dimensional line scanning module performs three-dimensional line scanning on a three-dimensional calibration block; for each target intersection line in at least two target intersection lines of the at least three calibration planes, determining scanning points on a target intersection line segment corresponding to each group of point cloud data according to the at least one group of point cloud data; and determining a conversion relation between the module coordinate system and the platform coordinate system according to the coordinates of at least part of the scanning points of the target intersection line segment. The technical scheme can be suitable for various three-dimensional line scanning systems which adopt line measurement to obtain three-dimensional shape data, and the universality is high.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional measurement technology, and in particular to a coordinate system calibration method, a stereo calibration block, a storage medium and a computer program product of a three-dimensional line scanning system. Background Art

[0002] In recent years, micro-nanoscale processing and manufacturing technologies have achieved rapid development, and higher requirements have been put forward for related precision measurement technologies. Precision three-dimensional measurement technology can obtain the morphological information of the sample to be measured, and has been widely used in aerospace, automobile, medical, semiconductor and other fields. Micro-nanoscale three-dimensional measurement technology can be roughly divided into two types: contact measurement and non-contact measurement. Contact measurement, such as mechanical probe profilometer, has the advantages of intuitive convenience, wide application range and high measurement accuracy. However, contact measurement technology is easy to damage the surface of the measured object during the measurement process, is sensitive to external interference, and the equipment is expensive. It is not suitable for industrial production that requires rapid online detection. Due to its non-destructive measurement characteristics, non-contact measurement technology has unique advantages in the field of micro-nanoscale morphological measurement. Non-contact measurement mainly includes optical method, electromagnetic method, ultrasonic method, etc. Commonly used optical measurement technologies mainly include photometric stereo vision, dual (multi) eye stereo vision, time of flight method, laser line scanning method, structured light projection method, interferometry method and line spectrum confocal method.

[0003] Both the laser line scanning method and the line spectrum confocal method are technologies that project a light plane onto the surface of an object to obtain the coordinates of the three-dimensional point at the intersection of the plane and the surface of the object to be measured. In actual three-dimensional surface measurement, the measuring instruments used by these two technologies (referred to as the three-dimensional line scanning module in this article) are used in conjunction with a precision displacement platform (referred to as the operation and control platform in this article). The intersection line contours are spliced ​​in combination with motion information to obtain the three-dimensional surface contour of an object with a complex morphology. To obtain accurate and reliable three-dimensional data, there are high requirements for the installation of the three-dimensional line scanning module and the operation and control platform. Slight angle deviations between the three-dimensional line scanning module and the operation and control platform will lead to incorrect measurement results. Errors are inevitable in mechanical processing and installation, so the coordinate system calibration of the three-dimensional line scanning module and the operation and control platform is crucial. Summary of the invention

[0004] The present invention is proposed in consideration of the above problems. The embodiments of the present invention provide a coordinate system calibration method, a stereo calibration block, a storage medium and a computer program product for a three-dimensional line scanning system. This technical solution can be applied to all three-dimensional line scanning systems, including laser line scanning method and (line) spectral confocal method, that use line measurement and combine the movement of the operation and control platform to obtain the three-dimensional morphological data of the target object. It has strong versatility and can more accurately calculate the deflection angle between the three-dimensional line scanning module and the operation and control platform, which is conducive to the high-precision calibration of the coordinate system of the three-dimensional line scanning system.

[0005] According to one aspect of the present invention, a method for calibrating the coordinate system of a three-dimensional line scanning system is provided. The three-dimensional line scanning system includes a three-dimensional line scanning module and a transportation control platform, on which a three-dimensional line scanning module and / or a stereo calibration block are arranged, and the transportation control platform is used to control the relative movement between the three-dimensional line scanning module and the stereo calibration block, the three-dimensional line scanning module has a module coordinate system, the transportation control platform has a platform coordinate system, the module coordinate axes of the module coordinate system correspond one-to-one to the platform coordinate axes of the platform coordinate system, and the stereo calibration block has at least three calibration planes intersecting with each other, and the intersection lines of each two intersecting calibration planes in at least three calibration planes are parallel to each other; the method includes: obtaining at least one of the three-dimensional line scanning planes collected by the three-dimensional line scanning module on the stereo calibration block A set of point cloud data is provided, each set of point cloud data is collected by a three-dimensional line scanning module during the relative movement of the three-dimensional line scanning module and the stereo calibration block along the first platform coordinate axis in the platform coordinate system, and each set of point cloud data includes the coordinates of each scan point collected in the module coordinate system; for each of at least two target intersection lines of at least three calibration planes, a scan point on a target intersection line segment corresponding to each set of point cloud data is determined according to at least one set of point cloud data, the target intersection line segment being a line segment on the target intersection line; and a conversion relationship between the module coordinate system and the platform coordinate system is determined according to the coordinates of at least part of the scan points of the target intersection line segment.

[0006] Optionally, the intersection of every two intersecting calibration planes in the at least three calibration planes is parallel to the second platform coordinate axis in the platform coordinate system, and the first platform coordinate axis and the second platform coordinate axis are perpendicular to each other and are both perpendicular to the preset light projection plane of the three-dimensional line scanning module; according to the coordinates of at least part of the scanning points of the target intersection line segment, the conversion relationship between the module coordinate system and the platform coordinate system is determined, including: correction operation: according to the coordinates of at least part of the scanning points of the target intersection line segment, the deflection angles of at least two target intersection lines around one or more module coordinate axes in the module coordinate system are determined; and according to the deflection angles of at least two target intersection lines around one or more module coordinate axes in the module coordinate system, the current at least two sets of point cloud data are corrected; if the preset condition is not met, for each of the at least two target intersection lines, the scanning points on the target intersection line segment corresponding to each set of point cloud data are determined according to the at least one set of corrected point cloud data, and the correction operation is returned to be performed; if the preset condition is met, the conversion relationship is determined according to the at least one set of corrected point cloud data and the at least one set of point cloud data before the first correction operation is performed.

[0007] Optionally, the preset conditions include: the deflection angle of at least two target intersection lines around one or more module coordinate axes meets the preset angle requirements; or, the preset conditions include: the deflection angle of at least two target intersection lines around one or more module coordinate axes meets the preset angle requirements, or the number of executions of the correction operation reaches a preset number threshold.

[0008] Optionally, the number of at least one group of point cloud data is two or more than two groups. When collecting any two different groups of point cloud data, the three-dimensional line scanning module group and the stereo calibration block are located at different relative positions along the second platform coordinate axis of the platform coordinate system, and the first platform coordinate axis and the second platform coordinate axis are perpendicular to each other and are both perpendicular to a preset light projection plane of the three-dimensional line scanning module group.

[0009] Optionally, the number of at least one group of point cloud data is two groups, and the deflection angle of at least two target intersection lines around one or more module coordinate axes in the module coordinate system is determined according to the coordinates of at least part of the scanning points of the target intersection line segment, including: for each of the at least two target intersection lines, according to the coordinates of at least part of the scanning points of the target intersection line segment, determining a first distance in the first plane between the target intersection line segment corresponding to the first group of point cloud data and the target intersection line segment corresponding to the second group of point cloud data, so as to obtain a first distance corresponding to the at least two target intersection lines one by one; for each of the at least two target intersection lines, according to the coordinates of at least part of the scanning points of the target intersection line segment, determining a second distance in the first plane between the first intersection point corresponding to each target intersection line and the second intersection point, so as to obtain a first distance corresponding to the at least two target intersection lines one by one. The second distance, the first intersection point is the intersection point where any straight line parallel to the second module coordinate axis in the module coordinate system intersects with the target intersection line segment corresponding to the first group of point cloud data, and the second intersection point is the intersection point where the straight line intersects with the target intersection line segment corresponding to the second group of point cloud data; according to the first distance corresponding to at least two target intersection lines one by one and the second distance corresponding to at least two target intersection lines one by one, determine the deflection angle of at least two target intersection lines around the third module coordinate axis in the module coordinate system; wherein the first plane is a plane parallel to the first module coordinate axis and the second module coordinate axis in the module coordinate system, the first module coordinate axis, the second module coordinate axis and the third module coordinate axis correspond to the first platform coordinate axis, the second platform coordinate axis and the third platform coordinate axis of the platform coordinate system one by one, and the module coordinate system and the platform coordinate system are both spatial rectangular coordinate systems.

[0010] Optionally, the preset conditions include: the first target distance is less than or equal to the first distance threshold; or, the preset conditions include: the first target distance is less than or equal to the first distance threshold, or, the number of executions of the correction operation reaches a preset number threshold; wherein, the first target distance is the first distance corresponding to any target intersection line, or the first distance corresponding to all target intersection lines, or the average value of the first distances corresponding to at least some of the target intersection lines.

[0011] Optionally, the number of at least one group of point cloud data is two groups, and the deflection angle of at least two target intersection lines around one or more module coordinate axes in the module coordinate system is determined based on the coordinates of at least part of the scanning points of the target intersection line segment, including: for each of the at least two target intersection lines, according to the coordinates of at least part of the scanning points of the target intersection line segment, determining a third distance in the second plane between the target intersection line segment corresponding to the first group of point cloud data and the target intersection line segment corresponding to the second group of point cloud data, so as to obtain a third distance corresponding to the at least two target intersection lines one by one; for each of the at least two target intersection lines, according to the coordinates of at least part of the scanning points of the target intersection line segment, determining a fourth distance in the second plane between the first intersection point and the second intersection point corresponding to each target intersection line, so as to obtain a third distance corresponding to the at least two target intersection lines one by one. The fourth distance, the first intersection point is the intersection point where any straight line parallel to the second module coordinate axis in the module coordinate system intersects with the target intersection line segment corresponding to the first set of point cloud data, and the second intersection point is the intersection point where the straight line intersects with the target intersection line segment corresponding to the second set of point cloud data; according to the third distance corresponding to at least two target intersection lines one by one and the fourth distance corresponding to at least two target intersection lines one by one, the deflection angle of at least two target intersection lines around the first module coordinate axis in the module coordinate system is determined; wherein the second plane is a plane parallel to the second module coordinate axis and the third module coordinate axis in the module coordinate system, the first module coordinate axis, the second module coordinate axis and the third module coordinate axis correspond to the first platform coordinate axis, the second platform coordinate axis and the third platform coordinate axis of the platform coordinate system one by one, and the module coordinate system and the platform coordinate system are both spatial rectangular coordinate systems.

[0012] Optionally, the preset conditions include: the second target distance is less than or equal to the second distance threshold; or, the preset conditions include: the second target distance is less than or equal to the second distance threshold, or, the number of executions of the correction operation reaches a preset number threshold; wherein, the second target distance is the third distance corresponding to any target intersection line, or the third distance corresponding to all target intersection lines, or the average value of the third distances corresponding to at least some of the target intersection lines.

[0013] Optionally, according to the deflection angle of at least two target intersection lines around one or more module coordinate axes in the module coordinate system, the current at least two groups of point cloud data are corrected, including: for the coordinates of each scanning point in the at least two groups of point cloud data, based on the deflection angle of at least two target intersection lines around the third module coordinate axis in the module coordinate system, the coordinates of the scanning point on the first module coordinate axis in the module coordinate system before correction, and the coordinates of the scanning point on the second module coordinate axis in the module coordinate system before correction, determining the corrected coordinates of the scanning point on the first module coordinate axis; based on the deflection angle of at least two target intersection lines around the first module coordinate axis, the coordinates of the scanning point on the second module coordinate axis before correction, and the coordinates of the scanning point on the third module coordinate axis before correction. Coordinates, determine the corrected coordinates of the scanning point on the third module coordinate axis; determine the corrected coordinates of the scanning point on the second module coordinate axis based on the deflection angle of at least two target intersection lines around the third module coordinate axis and the coordinates of the scanning point on the second module coordinate axis before correction, or, determine the corrected coordinates of the scanning point on the second module coordinate axis based on the deflection angle of at least two target intersection lines around the first module coordinate axis, the coordinates of the scanning point on the second module coordinate axis before correction, and the coordinates of the scanning point on the third module coordinate axis before correction; wherein the first module coordinate axis and the third module coordinate axis correspond to the first platform coordinate axis and the third platform coordinate axis of the platform coordinate system, respectively, and the module coordinate system and the platform coordinate system are both spatial rectangular coordinate systems.

[0014] According to another aspect of the present invention, a stereoscopic calibration block is provided. The stereoscopic calibration block has at least three calibration planes intersecting in pairs, each calibration plane is a plane, and intersection lines of every two intersecting calibration planes in the at least three calibration planes are parallel to each other.

[0015] Optionally, the three-dimensional calibration block includes a substrate and at least one identification block arranged on the upper surface of the substrate, each identification block is a right quadrangular prism with a trapezoidal bottom surface, the bottom surface of each identification block is perpendicular to the upper surface of the substrate and the lower base edge of the bottom surface of each identification block is in contact with the upper surface of the substrate, and at least three calibration planes include the upper surface of the substrate and at least part of the side surface of at least part of the identification blocks in at least one identification block.

[0016] According to another aspect of the present invention, a coordinate system calibration device for a three-dimensional line scanning system is further provided. The three-dimensional line scanning system comprises a three-dimensional line scanning module and a transport control platform. The transport control platform is provided with a three-dimensional line scanning module and / or a three-dimensional calibration block. The transport control platform is used to control the relative movement between the three-dimensional line scanning module and the three-dimensional calibration block. The three-dimensional line scanning module has a module coordinate system, and the transport control platform has a platform coordinate system. The module coordinate axes of the module coordinate system correspond to the platform coordinate axes of the platform coordinate system in one-to-one correspondence. The three-dimensional calibration block has at least three calibration planes intersecting with each other. The intersection lines of every two intersecting calibration planes in the at least three calibration planes are parallel to each other. The device comprises:

[0017] An acquisition module is used to acquire at least one set of point cloud data collected by the three-dimensional line scanning module group when performing three-dimensional line scanning on the three-dimensional calibration block, each set of point cloud data is collected by the three-dimensional line scanning module group during the relative movement of the three-dimensional line scanning module group and the three-dimensional calibration block along the first platform coordinate axis in the platform coordinate system, and each set of point cloud data includes the coordinates of each scan point collected in the module coordinate system;

[0018] A first determination module is used to determine, for each of at least two target intersection lines of at least three calibration planes, a scanning point on a target intersection line segment corresponding to each set of point cloud data according to at least one set of point cloud data, where the target intersection line segment is a line segment on the target intersection line;

[0019] The second determination module is used to determine the conversion relationship between the module coordinate system and the platform coordinate system according to the coordinates of at least part of the scanning points of the target intersection line segment.

[0020] According to yet another aspect of the present invention, a storage medium is provided on which program instructions are stored. The program instructions are used to execute the above-mentioned coordinate system calibration method of the three-dimensional line scanning system when running.

[0021] According to yet another aspect of the present invention, there is provided a computer program product, comprising computer program instructions, which are used to execute the coordinate system calibration method of the three-dimensional line scan system as described above when the computer program instructions are run.

[0022] The above technical solution uses a three-dimensional line scanning module to collect point cloud data from a stereoscopic calibration block having at least two parallel intersection lines. It can utilize the fact that the intersection line features in the stereoscopic calibration block are relatively obvious and it is easy to obtain accurate point cloud data. Based on at least two parallel intersection lines, the conversion relationship between the module coordinate system and the platform coordinate system is determined, and then the deflection angle between the three-dimensional line scanning module and the operation and control platform is accurately calculated, which is conducive to the high-precision calibration of the coordinate system of the three-dimensional line scanning system. On the other hand, the stereoscopic calibration block used in this method only needs to have at least two mutually parallel intersection lines. The processing accuracy requirements for the stereoscopic calibration block are relatively low, the processing difficulty is small, and the cost is low. In addition, this method can be applied to a variety of three-dimensional line scanning systems including laser line scanning method and (line) spectral confocal method that use line measurement and combine the movement of the operation and control platform to obtain the three-dimensional morphological data of the target object, and has strong versatility.

[0023] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other purposes, features and advantages of the present invention will become more apparent by describing the embodiments of the present invention in more detail in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0025] Figure 1 A schematic diagram showing the principle of a laser line scanning method according to an embodiment of the present invention is shown;

[0026] Figure 2 A schematic diagram showing the principle of a spectral confocal method according to an embodiment of the present invention is shown;

[0027] Figure 3 A schematic diagram showing measurement results of a three-dimensional line scanning system according to an embodiment of the present invention is shown;

[0028] Figure 4 A schematic diagram of the projection of the scanning line of the three-dimensional line scanning module in the xy plane of the module coordinate system when the three-dimensional line scanning module is deflected around the z-axis of the platform coordinate system according to one embodiment of the present invention is shown;

[0029] Figure 5A schematic diagram of the projection of the scanning line of the three-dimensional line scanning module group in the xz plane of the module coordinate system when the three-dimensional line scanning module group is deflected around the y-axis of the platform coordinate system according to one embodiment of the present invention is shown;

[0030] Figure 6 A schematic diagram of the projection of the scanning line of the three-dimensional line scanning module group in the yz plane of the module coordinate system when the three-dimensional line scanning module group is deflected around the x-axis of the platform coordinate system according to one embodiment of the present invention is shown;

[0031] Figure 7 A schematic diagram of the structure of a planar ceramic calibration plate in the related art is shown;

[0032] Figure 8 A top view of a metal calibration plate in the related art is shown;

[0033] Fig. 9 A schematic flow chart of a coordinate system calibration method for a three-dimensional line scanning system according to an embodiment of the present invention is shown;

[0034] Fig.10 A schematic diagram of the structure of a stereo calibration block according to an embodiment of the present invention is shown;

[0035] Fig.11 A schematic diagram showing a target intersection line in a module coordinate system according to an embodiment of the present invention is shown;

[0036] Fig.12 A schematic structural diagram of a coordinate system calibration device for a three-dimensional line scanning system according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0038] See also Figure 1As shown, it is a schematic diagram of the principle of the laser line scanning method according to an embodiment of the present invention. When the laser line scanning method is used to measure the target object, the measuring instrument (a three-dimensional line scanning module in the embodiment of the present invention) can emit a laser to the target object, and the light-receiving lens of the three-dimensional line scanning module can collect the light emitted by the target object and form an image on the light receiving element. When the distance between the three-dimensional line scanning module and the target object changes, the angle of the collected reflected light also changes, and the imaging position on the light receiving element changes accordingly. The change in the imaging position on the light receiving element is proportional to the movement of the target object. By reading the change in the imaging position, the movement of the target object can be measured, and the movement is also the distance between the target object and the three-dimensional line scanning module. The laser line scanning method can project a light plane onto the surface of the target object, and measure the three-dimensional morphology at the intersection of the light plane and the surface of the target object through the above-mentioned measurement principle, that is, the three-dimensional morphology of a line can be measured each time.

[0039] See also Figure 2 As shown, it is a schematic diagram of the principle of the spectral confocal method according to an embodiment of the present invention. When the spectral confocal method is adopted, a beam of wide-spectrum complex light (in white) can be emitted to the target object, and spectral dispersion occurs through the dispersive objective lens. Monochromatic light of different wavelengths can be formed within the range of the measuring instrument (a three-dimensional line scanning module in the embodiment of the present invention), and monochromatic light of different wavelengths has different focal lengths. Monochromatic light of different wavelengths is reflected by the surface of the target object after reaching the surface of the target object. When the wavelength of the monochromatic light meets the confocal condition, it can be sensed by the spectrometer of the three-dimensional line scanning module through the small hole. The distance between the three-dimensional line scanning module and the target object can be calculated by the wavelength of the sensed monochromatic light. Both the line spectral confocal method and the spectral confocal method utilize the principle of dispersion. In the line spectral confocal method, the three-dimensional morphology of a line can be measured each time.

[0040] As mentioned above, the angle deviation between the 3D line scan module and the control platform will cause the measured shape of the target object to be inconsistent with the actual shape. Figure 3 As shown, it is a schematic diagram of measurement results of a three-dimensional line scanning system according to an embodiment of the present invention. Figure 3 In the illustrated embodiment, the three-dimensional line scanning system includes an operation and control platform and a three-dimensional line scanning module (shown as a "three-dimensional module" in the figure), the operation and control platform has a platform coordinate system, and the module platform has a module coordinate system, and both coordinate systems are spatial rectangular coordinate systems, both including an x-axis, a y-axis and a z-axis, and the x-axis, y-axis and z-axis of the two coordinate systems correspond one to one. Figure 3The x-axis, y-axis, and z-axis of the module coordinate system are shown in the upper left corner. When using a three-dimensional line scan module to perform three-dimensional measurement of a target object, the transportation and control platform can control the relative movement between the three-dimensional line scan module and the target object, and the direction of the relative movement may include the direction of the straight line where the x-axis and / or y-axis of the platform coordinate system are located. During the relative movement of the three-dimensional line scan module and the transportation and control platform, the three-dimensional line scan module can emit a scan line (such as the above-mentioned laser light, complex light, etc.) to the target object along the straight line direction where the z-axis of the module coordinate system is located to obtain the three-dimensional shape measurement data of the target object. It can be understood that the light plane formed by the scan line emitted by the three-dimensional line scan module each time is parallel to the z-axis of the module coordinate system. Figure 3 A line parallel to the x-axis of the module coordinate system is shown below the three-dimensional line scanning module. This line can be understood as the intersection of the light plane formed by the scanning line when the three-dimensional line scanning module emits the scanning line and any plane parallel to the x-axis and y-axis of the module coordinate system. Figure 3 The extending direction of the intersection line shown can be called the line length direction of the scanning line. Figure 3 The three-dimensional shape measurement data D1 of the target object obtained when there is no deflection angle between the three-dimensional line scanning module and the transportation and control platform, and the three-dimensional shape measurement data D2 of the target object obtained when there is a deflection angle between the transportation and control platform and the three-dimensional line scanning module are shown. Taking the relative motion direction between the three-dimensional line scanning module and the target object as the straight line direction where the y-axis of the platform coordinate system is located as an example, when the platform coordinate system is used as the standard coordinate system, if the three-dimensional line scanning module deflects around the z-axis of the platform coordinate system (that is, the line length direction of the scanning line is not perpendicular to the relative motion direction), the measured shape of the projection of the target object on the xy plane of the module coordinate system will be deformed. For example, when the actual shape of the projection of the target object on the xy plane is a rectangle, if the three-dimensional line scanning module deflects around the z-axis of the platform coordinate system, the measured shape of the projection of the target object on the xy plane of the module coordinate system is a parallelogram. Similarly, when the 3D line scan module is deflected around the y-axis of the platform coordinate system (i.e., the line length direction of the scan line is not parallel to the x-axis of the platform coordinate system), the 3D shape measurement data of the target object at the same height is inconsistent. The 3D shape measurement data obtained when the 3D line scan module is deflected around the x-axis of the platform coordinate system has deviations, which will not be elaborated here.

[0041] When there is a deflection angle between the 3D line scan module and the operation control platform, the module coordinate system of the 3D line scan module can be calibrated to obtain the conversion relationship between the module coordinate system and the platform coordinate system. Figure 4 , Figure 5 as well as Figure 6 As shown, Figure 4is a schematic diagram of the projection of the scanning line of the three-dimensional line scanning module in the xy plane of the module coordinate system when the three-dimensional line scanning module is deflected around the z-axis of the platform coordinate system according to one embodiment of the present invention, Figure 5 is a schematic diagram of the projection of the scanning line of the three-dimensional line scanning module in the xz plane of the module coordinate system when the three-dimensional line scanning module is deflected around the y-axis of the platform coordinate system according to one embodiment of the present invention, Figure 6 The figure is a schematic diagram of the projection of the scanning line of the 3D line scanning module in the yz plane of the module coordinate system when the 3D line scanning module is deflected around the x-axis of the platform coordinate system according to one embodiment of the present invention. When calibrating the module coordinate system, the geometric features (such as points, lines, surfaces, etc.) of the calibration object with a standard morphology can be measured, and the collinearity, coplanarity, parallelism, verticality and other information can be obtained to calculate the deflection angle between the 3D line scanning module and the operation and control platform. Figure 4 , Figure 5 as well as Figure 6 In the illustrated embodiment, the relative motion direction between the three-dimensional line scanning module and the calibration object is the direction of the straight line where the y-axis of the platform coordinate system is located. Figure 4 In , the angle between the projection line of the scanning line Xm on the xy plane of the module coordinate system and the x-axis of the platform coordinate system is recorded as α, and α can indicate the deflection angle of the three-dimensional line scanning module around the z-axis of the platform coordinate system. Similarly, Figure 5 In the figure, the angle between the projection line of the scanning line on the xz plane of the module coordinate system and the x-axis of the platform coordinate system is recorded as β, and β can indicate the deflection angle of the three-dimensional line scanning module around the y-axis of the platform coordinate system. Figure 6 In , the angle between the projection line of the scanning line on the yz plane of the module coordinate system and the z axis of the platform coordinate system is recorded as γ, and γ can indicate the deflection angle of the three-dimensional line scanning module around the x axis of the platform coordinate system. It can be understood that by obtaining α, β, and γ, the three-dimensional shape measurement data of the calibration object can be corrected. For example, in Figure 5 In the 3D shape measurement data of the calibration object, the height deviation on the xz plane can be calculated by formula (1)(2)(3):

[0042] h1=z1cosβ (1);

[0043] h2=z2cosβ (2);

[0044] h=h2-h1=(z2-z1)cosβ (3);

[0045] In formulas (1), (2), and (3), h1 is the straight-line distance between the first transmitting end of the scanning line of the three-dimensional line scanning module group and the target object, h2 is the straight-line distance between the second transmitting end of the scanning line of the three-dimensional line scanning module group and the target object, z1 is the transmitting length from the first transmitting end to the target object when the three-dimensional line scanning module group transmits the scanning line along the transmitting direction of the scanning line, z2 is the transmitting length from the second transmitting end to the target object when the three-dimensional line scanning module group transmits the scanning line along the transmitting direction of the scanning line, and h is the height difference between the first transmitting end and the second transmitting end of the three-dimensional line scanning module group.

[0046] For example, in Figure 6 In the yz plane, the height deviation of the three-dimensional shape measurement data of the calibration object can be calculated by formula (4)(5)(6):

[0047] h1=z1cosγ (4);

[0048] h2=z2cosγ (5);

[0049] h=h2-h1=(z2-z1)cosγ (6);

[0050] In formulas (4), (5), and (6), h1 is the straight-line distance between the first transmitting end of the scanning line of the three-dimensional line scanning module group and the target object, h2 is the straight-line distance between the second transmitting end of the scanning line of the three-dimensional line scanning module group and the target object, z1 is the transmitting length from the first transmitting end to the target object when the three-dimensional line scanning module group transmits the scanning line along the transmitting direction of the scanning line, z2 is the transmitting length from the second transmitting end to the target object when the three-dimensional line scanning module group transmits the scanning line along the transmitting direction of the scanning line, and h is the actual height of the calibration object.

[0051] In the related art, the calibration object can be a flat ceramic calibration plate or a metal calibration plate. Figure 7 As shown, it is a structural schematic diagram of a planar ceramic calibration plate in the related art. At least three characteristic circles can be set on the planar ceramic calibration plate. The three-dimensional line scanning module can scan the planar ceramic calibration plate to obtain point cloud data (i.e. the aforementioned three-dimensional morphology measurement data), and extract the point cloud data belonging to the characteristic circle in the point cloud data, and perform ellipse fitting on the obtained characteristic circle to extract the center of the circle. Subsequently, the angle between the center line of the circle in the horizontal direction and the center line of the circle in the vertical direction can be calculated as the above-mentioned α angle, and the above-mentioned β angle can be obtained according to the height deviation of the two ends measured by the scanning line on the surface of the target object at the same height, or, the collected xy plane point cloud data can be plane fitted to calculate the normal vector, and the angle between the obtained normal vector and the z-axis of the module coordinate system can be used as the above-mentioned β angle. The calibration object can also be a three-dimensional metal calibration plate. Please refer to Figure 8 As shown in FIG. 1 , it is a top view of a metal calibration plate in the related art. Figure 8 In the example shown, the shape of the metal calibration plate is a prism, including plane ①, plane ② and plane ③, and plane ③ has intersection lines with plane ① and plane ② respectively, and the two intersection lines are perpendicular to each other. By performing xy plane fitting on the collected point cloud data, the morphological data of the two intersection lines on the xy plane can be obtained, and the angle between the two intersection lines can be calculated as the above-mentioned angle α. The method for calculating the above-mentioned angle β is similar to the method for calculating the angle β using a planar ceramic calibration plate, which will not be repeated here. When using a planar ceramic calibration plate to calibrate the module coordinate system, it is more difficult to extract the center of the characteristic circle. Since the height difference between the characteristic circle area and the non-characteristic circle area on the surface of the planar ceramic calibration plate is extremely small, it is difficult to accurately extract the characteristic circle area from the point cloud data, and the grayscale image obtained by laser line scanning and the intensity image obtained by the spectral confocal method are both spliced ​​images. It is also difficult to accurately extract the center position of the circle, and it is also difficult to judge whether the corrected point cloud data is accurate. When using a metal three-dimensional calibration plate, with Figure 8 Taking the metal three-dimensional calibration plate shown as an example, it is necessary to ensure that the intersection line between plane ① and plane ② and the intersection line between plane ② and plane ③ are perpendicular to each other. The processing is difficult, and it is difficult to accurately measure the deflection angle around each coordinate axis during the calibration process, and it is difficult to verify the accuracy of the corrected point cloud data.

[0052] In order to at least partially solve the above technical problems, the embodiments of the present invention provide a coordinate system calibration method, a stereo calibration block, a storage medium and a computer program product for a three-dimensional line scanning system. This technical solution can be applied to a variety of three-dimensional line scanning systems that use line measurement and combine the movement of a control platform to obtain three-dimensional morphological data of a target object, including laser line scanning method and (line) spectral confocal method. It has strong versatility and can more accurately calculate the deflection angle between the three-dimensional line scanning module and the control platform, which is conducive to the high-precision calibration of the coordinate system of the three-dimensional line scanning system.

[0053] See also Fig. 9 As shown, it is a schematic flow chart of a coordinate system calibration method for a three-dimensional line scanning system according to an embodiment of the present invention. The three-dimensional line scanning system includes a three-dimensional line scanning module and a transportation control platform. The transportation control platform is provided with a three-dimensional line scanning module and / or a stereo calibration block. The transportation control platform is used to control the relative movement between the three-dimensional line scanning module and the stereo calibration block. The three-dimensional line scanning module has a module coordinate system, and the transportation control platform has a platform coordinate system. The module coordinate axes of the module coordinate system correspond one-to-one to the platform coordinate axes of the platform coordinate system. The stereo calibration block has at least three calibration planes that intersect with each other, and the intersection lines of every two intersecting calibration planes in the at least three calibration planes are parallel to each other. As shown in FIG. Fig. 9 As shown, the coordinate system calibration method of the three-dimensional line scanning system includes: step S910, step S920 and step S930.

[0054] Exemplarily, the three-dimensional line scanning system may include a three-dimensional line scanning module for emitting scanning lines (such as laser light or composite light) and receiving scanning lines reflected back from the surface of the target object (in the embodiment of the present invention, a three-dimensional calibration block). Taking the three-dimensional line scanning module using the laser line scanning method as an example, it may include a laser projector for emitting laser light, a line scanning camera for obtaining a distorted image formed by the laser light on the surface of the target object, and a control module for controlling the laser projector and the line scanning camera to work synchronously. The line scanning camera may be preset with a module coordinate system, and the control module is also used to calculate the three-dimensional coordinates of the surface of the target object in the module coordinate system based on the distorted image. Taking the line scanning camera as an example, it may have a camera coordinate system and an image coordinate system. The origin of the camera coordinate system is located at the optical center of the line scanning camera, and there are three mutually perpendicular coordinate axes passing through the origin. When the line scanning camera obtains a distorted image, a preset pixel point in the image can be used as the coordinate origin, and two coordinate axes passing through the coordinate origin and perpendicular to each other are obtained to obtain the image coordinate system. Those skilled in the art will understand that a line scan camera has an intrinsic parameter matrix (parameters may include focal length, principal point position) and an extrinsic parameter matrix (rotation matrix and translation vector of the line scan camera relative to the world coordinate system). The intrinsic parameter matrix can be used to convert the pixel position in the image coordinate system into three-dimensional coordinates in the camera coordinate system, and the extrinsic parameter matrix can be used to convert the three-dimensional coordinates in the camera coordinate system into module coordinates in the module coordinate system (which can be considered as the world coordinate system of the three-dimensional line scan module).

[0055] Exemplarily, the three-dimensional line scanning system may further include a transport control platform, which may translate in a plane (which may be referred to as a "moving plane") or rotate around a fixed rotation axis in the moving plane. The object connected to the transport control platform may move synchronously with the transport control platform, so the physical position of the transport control platform described herein and the physical position of the object connected to the transport control platform (such as a three-dimensional line scanning module group or a stereoscopic calibration block or a target object) may be considered to be the same, and the two may be expressed interchangeably. In some embodiments, the three-dimensional line scanning module group may be arranged on the transport control platform, and connected to the transport control platform so that the three-dimensional line scanning module group is driven by the transport control platform to move along the motion trajectory of the transport control platform. In the process of the transport control platform driving the three-dimensional line scanning module group to move, the stereoscopic calibration block may remain stationary, and the three-dimensional line scanning module group may emit scanning lines to the stereoscopic calibration block in a stationary state. In other embodiments, the three-dimensional line scanning module group may be independent of the transport control platform, and the stereoscopic calibration block may be arranged on the transport control platform so that the transport control platform drives the stereoscopic calibration block to move. In the process of the transportation and control platform driving the three-dimensional calibration block to move, the three-dimensional line scanning module can remain stationary and emit scanning lines to the three-dimensional calibration block in motion. The transportation and control platform can have a platform coordinate system. Within the moving range of the transportation and control platform, two mutually perpendicular grating rulers can be set. For example, when the transportation and control platform stays at a preset initial physical position, the reading of the grating ruler can be set to 0, and the physical position can be determined as the origin O of the platform coordinate system. A first grating ruler can be set along the first direction through the origin O, and the axis where the first grating ruler is located can be used as the X-axis of the platform coordinate system. A second grating ruler is set perpendicular to the X-axis and through the origin O. The axis where the second grating ruler is located can be used as the Y-axis of the platform coordinate system. After the platform coordinate system is established, each time the transportation and control platform moves, the corresponding X-axis coordinates and Y-axis coordinates can be read from the first grating ruler and the second grating ruler, and the (X, Y) coordinates can be used to represent the physical position of the object connected to the transportation and control platform. It can be understood that (X, Y) can be coordinate data used to represent the displacement of an object connected to the transportation control platform.

[0056] Exemplarily, the module coordinate axes of the module coordinate system may correspond one-to-one to the platform coordinate axes of the platform coordinate system. Specifically, the angle between any two module coordinate axes in the module coordinate system is equal to the angle between the corresponding two module coordinate axes in the platform coordinate system. Exemplarily, the stereo calibration block may have a plurality of planes constituting the stereo calibration block, wherein at least three calibration planes may exist in the planes constituting the stereo calibration block, and at least three calibration planes intersect with each other and the intersection lines of each two intersecting calibration planes are parallel to each other. Please refer to Fig.10 As shown, it is a schematic structural diagram of a stereo calibration block according to an embodiment of the present invention. Fig.10The three-dimensional calibration block shown is composed of a substrate and a marking block arranged above the substrate, wherein the three-dimensional calibration block can be an integrated structure, or the substrate and the marking block can be fixedly / movably connected. Fig.10 The calibration plane includes plane ①, plane ② and plane ③. The intersection line between plane ① and plane ② (the intersection line between line segment a and line segment A) is parallel to the intersection line between plane ② and plane ③ (the intersection line between line segment b and line segment B). It can be understood that Fig.10 The shape of the three-dimensional calibration block shown is only an example. For example, the substrate can also be any geometric body such as a prism or a prism cone, whose upper and lower surfaces are plane and parallel to each other. The identification block can also be any geometric body such as a triangular prism or an oblique quadrangular prism, whose bottom surface is perpendicular to the side surface. The shape of the three-dimensional calibration block satisfies the requirement of having at least three calibration planes intersecting with each other, and the intersection lines of each two intersecting calibration planes in the at least three calibration planes are parallel to each other.

[0057] In step S910, at least one set of point cloud data collected by the three-dimensional line scanning module when performing three-dimensional line scanning on the stereo calibration block is obtained. Each set of point cloud data is collected by the three-dimensional line scanning module during the relative movement of the three-dimensional line scanning module and the stereo calibration block along the first platform coordinate axis in the platform coordinate system. Each set of point cloud data includes the coordinates of each collected scanning point in the module coordinate system.

[0058] Exemplarily, the relative movement direction between the three-dimensional line scanning module group and the operation and control platform can be parallel to a certain platform coordinate axis (recorded as the first platform coordinate axis) of the operation and control coordinate system, and the first platform coordinate axis can be a coordinate axis parallel to the bottom surface of the stereo calibration block. Specifically, during the relative movement between the three-dimensional line scanning module group and the stereo calibration block, one or more groups of point cloud data collected by the three-dimensional line scanning module group can be obtained. When there are multiple groups of point cloud data collected by the three-dimensional line scanning module group, for any two groups of point cloud data, the area of ​​the line scanning surface (the surface for reflecting the scanning line) of the stereo calibration block corresponding to one group of point cloud data is at least partially different from the area of ​​the line scanning surface of the stereo calibration block corresponding to another group of point cloud data. Each group of point cloud data may include the coordinates of each scanning point at the corresponding position on the stereo calibration block in the module coordinate system when the scanning line emitted by the three-dimensional line scanning module group reaches the surface of the stereo calibration block. It can be understood that during the relative movement between the three-dimensional line scan module and the stereo calibration block, the range of the three-dimensional line scan can cover at least two target intersection lines of the intersection lines of every two intersecting calibration planes of the stereo calibration block or part of the points on each target intersection line of at least two target intersection lines. In other words, the range of the three-dimensional line scan can include the entire area of ​​the line scan surface of the stereo calibration block, and can also include a part of the area of ​​the line scan surface of the stereo calibration block including part of the points on the target intersection line. Accordingly, the multiple sets of point cloud data obtained can include the coordinates of each scanning point located on the target intersection line in the module coordinate system. The target intersection line can be selected by the user from the multiple intersection lines of the intersecting calibration planes, and the embodiment of the present invention does not specifically limit the selection of the target intersection line.

[0059] In step S920, for each of the at least two target intersection lines of the at least three calibration planes, a scanning point on a target intersection line segment corresponding to each set of point cloud data is determined according to at least one set of point cloud data, where the target intersection line segment is a line segment on the target intersection line.

[0060] Exemplarily, the stereo calibration block may have three or more calibration planes, and every two calibration planes may have an intersection line, so the stereo calibration block may have two or more intersection lines of calibration planes, and the user may select at least two target intersection lines from the intersection lines of the calibration planes. For each target intersection line, one or more groups of point cloud data in at least one group of point cloud data may include the coordinates of at least some of the points on the target intersection line in the module coordinate system. For each group of point cloud data, when the group of point cloud data includes the coordinates of at least some of the points of a certain target intersection line in the module coordinate system, the line segment formed by the part of the points may be used as the target intersection line segment corresponding to the target intersection line, and the part of the points may be used as the scanning point on the target intersection line segment corresponding to the target intersection line. It can be understood that when the group of point cloud data includes the coordinates of all the points of the target intersection line in the module coordinate system, the target intersection line is used as its corresponding target intersection line segment. When the set of point cloud data includes the coordinates of some points of the target intersection line in the module coordinate system, the target intersection line segment corresponding to the target intersection line is a part of the target intersection line.

[0061] In step S930, a conversion relationship between the module coordinate system and the platform coordinate system is determined according to the coordinates of at least part of the scanning points of the target intersection line segment.

[0062] Exemplarily, each target intersection line may correspond to a respective target intersection line segment. For each target intersection line segment, the coordinates of some or all scanning points on the target intersection line segment may be obtained in the point cloud data corresponding to the target intersection line segment, and the coordinates of the scanning points on the obtained target intersection line segment may indicate the deflection of the module coordinate system relative to the platform coordinate system, and the conversion relationship between the module coordinate system and the platform coordinate system may be determined based on the deflection. In a specific embodiment, the conversion relationship may be represented by the deflection angle of each module coordinate axis of the module coordinate system around the other two module coordinate axes. In another specific embodiment, the conversion relationship may be represented by the mapping relationship between each coordinate point in the module coordinate system and each coordinate point in the platform coordinate system (which may be described by a coordinate transformation matrix composed of a rotation matrix and a translation vector). It can be understood that for each point in the module coordinate system, the coordinates of the point may obtain the corresponding conversion coordinates based on the conversion relationship, and the relative position of the point in the module coordinate system is consistent with the relative position of the point in the platform coordinate system that has the same conversion coordinates as the point in the platform coordinate system. Similarly, for each point in the platform coordinate system, the coordinates of the point can obtain corresponding transformation coordinates based on the transformation relationship, and the relative position of the point in the platform coordinate system is consistent with the relative position of the point with the same transformation coordinate in the module coordinate system. Those skilled in the art can understand that the module coordinate system can be calibrated based on the determined transformation relationship, or the platform coordinate system can be calibrated. The embodiment of the present invention describes the coordinate system calibration method of the three-dimensional line scanning system using the module coordinate system as the calibration object. When the platform coordinate system is used as the calibration object, the coordinate system calibration method of the three-dimensional line scanning system according to the embodiment of the present invention can also be used.

[0063] The above technical solution uses a three-dimensional line scanning module to collect point cloud data from a stereoscopic calibration block having at least two parallel intersection lines. It can utilize the fact that the intersection line features in the stereoscopic calibration block are relatively obvious and it is easy to obtain accurate point cloud data. Based on at least two parallel intersection lines, the conversion relationship between the module coordinate system and the platform coordinate system is determined, and then the deflection angle between the three-dimensional line scanning module and the operation and control platform is accurately calculated, which is conducive to the high-precision calibration of the coordinate system of the three-dimensional line scanning system. On the other hand, the stereoscopic calibration block used in this method only needs to have at least two mutually parallel intersection lines. The processing accuracy requirements for the stereoscopic calibration block are relatively low, the processing difficulty is small, and the cost is low. In addition, this method can be applied to a variety of three-dimensional line scanning systems including laser line scanning method and (line) spectral confocal method that use line measurement and combine the movement of the operation and control platform to obtain the three-dimensional morphological data of the target object, and has strong versatility.

[0064] Optionally, the intersection of every two intersecting calibration planes in the at least three calibration planes is parallel to the second platform coordinate axis in the platform coordinate system, and the first platform coordinate axis and the second platform coordinate axis are perpendicular to each other and are both perpendicular to the preset light projection plane of the three-dimensional line scanning module; according to the coordinates of at least part of the scanning points of the target intersection line segment, the conversion relationship between the module coordinate system and the platform coordinate system is determined, including: correction operation: according to the coordinates of at least part of the scanning points of the target intersection line segment, the deflection angles of at least two target intersection lines around one or more module coordinate axes in the module coordinate system are determined; and according to the deflection angles of at least two target intersection lines around one or more module coordinate axes in the module coordinate system, the current at least two sets of point cloud data are corrected; if the preset condition is not met, for each of the at least two target intersection lines, the scanning points on the target intersection line segment corresponding to each set of point cloud data are determined according to the at least one set of corrected point cloud data, and the correction operation is returned to be performed; if the preset condition is met, the conversion relationship is determined according to the at least one set of corrected point cloud data and the at least one set of point cloud data before the first correction operation is performed.

[0065] Exemplarily, when a three-dimensional line scan module is used to perform a three-dimensional line scan on a stereo calibration block, the posture of the stereo calibration block can meet the following conditions: the intersection lines of the intersecting calibration planes are parallel to the second platform coordinate axis, wherein the second platform coordinate axis is perpendicular to the first platform coordinate axis. In the three-dimensional line scan system, a preset light projection plane for the three-dimensional line scan module can be preset. It can be understood that when each module coordinate axis of the module coordinate system is parallel to the corresponding platform coordinate axis in the platform coordinate system, when the scanning line of the three-dimensional line scan module is projected along the projection direction (the direction from the three-dimensional line scan module to the stereo calibration block), the projection path of each point on the scanning line along the projection direction can form a projection plane (i.e., the above-mentioned light plane), and the plane parallel to the projection plane can be used as the preset light projection plane for the three-dimensional line scan module. In the platform coordinate system, the first platform coordinate axis and the second platform coordinate axis are both perpendicular to the preset light projection plane of the three-dimensional line scan module. The 3D line scanning system may have a control device that is communicatively connected to the 3D line scanning module, and the control device may obtain point cloud data collected by the 3D line scanning module to determine the coordinates of the scanning points on the target intersection line segment and at least some of the determined scanning points according to the point cloud data. After determining the coordinates of at least some of the scanning points on the target intersection line segment, the control device may perform a correction operation.

[0066] In a specific embodiment, the number of the determined target intersection lines is 2. For the convenience of description, the target intersection line segment corresponding to one of the target intersection lines is recorded as line segment L1 (for example, Fig.10 The scanning points on the line segment L1 are recorded as point set P1, and correspondingly, the target intersection line segment corresponding to the other target intersection line is recorded as line segment L2 (for example Fig.10The scanning points on the line segment L2 are recorded as point set P2. The module coordinate system may include a first module coordinate axis corresponding to the first platform coordinate axis and a second module coordinate axis corresponding to the second platform coordinate axis, wherein the first module coordinate axis and the second module coordinate axis are perpendicular to each other, and the module coordinate system also includes a third module coordinate axis perpendicular to both the first module coordinate axis and the second module coordinate axis. Any two module coordinate axes can form a coordinate plane, and according to the coordinates of at least part of the scanning points of each target intersection line segment, the projection coordinates of at least part of the scanning points of the target intersection line segment in each coordinate plane can be obtained. The control device can calculate the deflection angle of the line segment L1 around one or more module coordinate axes of the module coordinate system based on the coordinates of at least part of the scanning points in the point set P1 in at least one set of point cloud data. Specifically, for any coordinate plane of the module coordinate system, the angles between the projection of the line segment L1 on the coordinate plane and the two module coordinate axes in the coordinate plane can be calculated according to the coordinates of at least some of the scanning points in the point set P1, and the deflection angle of the line segment L1 (and its target intersection line) around another module coordinate axis perpendicular to the coordinate plane can be determined according to the calculated angle. Similarly, the control device can calculate the deflection angle of the line segment L2 (and its target intersection line) around one or more module coordinate axes of the module coordinate system based on the coordinates of at least some of the scanning points in the point set P2 in at least one set of point cloud data. The control device can correct the current groups of point cloud data based on the deflection angles of the line segments L1 and L2 around one or more module coordinate axes. The control device can obtain the current conversion relationship between the module coordinate system and the platform coordinate system according to the groups of point cloud data before the first correction operation and the groups of point cloud data after correction. In the control device, a preset condition can be set, and the preset condition is used to verify whether the current conversion relationship obtained meets the correction requirements or whether the number of corrections reaches the upper limit. When the preset conditions are not met, the scanning points on the target intersection line segment corresponding to each set of point cloud data can be re-determined in at least one set of corrected point cloud data, and the aforementioned correction operation can be re-executed based on the re-determined scanning points until the preset conditions are met.

[0067] The above technical solution obtains the deflection angle of the target intersection line around one or more module coordinate axes, and can accurately quantify the deflection of the module coordinate axis in the corresponding one or more dimensions through the deflection of the target intersection line in one or more dimensions in space, which is conducive to achieving high-precision calibration of the module coordinate system. On the other hand, after each correction of the point cloud data, it can be determined whether the corrected point cloud data meets the preset conditions. When the preset conditions are not met, the correction operation can be iteratively performed on the corrected point cloud data, which is conducive to ensuring that the calibrated module coordinate system meets the use requirements.

[0068] Optionally, the preset conditions include: the deflection angle of at least two target intersection lines around one or more module coordinate axes meets the preset angle requirements; or, the preset conditions include: the deflection angle of at least two target intersection lines around one or more module coordinate axes meets the preset angle requirements, or the number of executions of the correction operation reaches a preset number threshold.

[0069] Exemplarily, the preset condition may only include: the deflection angle of at least two target intersection lines around one or more module coordinate axes meets the preset angle requirement. The preset angle requirement may, for example, be less than or equal to a preset deflection angle threshold (e.g., 0.01°). Different deflection angle thresholds may be set for the deflection angles around different module coordinate axes, or the same deflection angle threshold may be set. The preset condition may also include: a first preset condition or a second preset condition, the first preset condition being that the deflection angle of at least two target intersection lines around one or more module coordinate axes meets the preset angle requirement, and the second preset condition being that the number of executions of the correction operation reaches a preset number threshold. The preset number threshold may be defined according to actual needs, for example, 50 times. When any one of the first preset condition and the second preset condition is met, the conversion relationship may be determined based on the corrected current point cloud data and the point cloud data before the first correction operation is performed.

[0070] The above technical solution determines whether the preset conditions are met through the deflection angle of the target intersection line around the module coordinate axis, or the number of times the correction operation is executed. The former is conducive to making the calibrated module coordinate axis more accurate, and the latter can effectively save the time of invalid correction operation due to factors such as large errors in point cloud data or inaccurate calculation of deflection angle.

[0071] Optionally, the number of at least one group of point cloud data is two or more than two groups. When collecting any two different groups of point cloud data, the three-dimensional line scanning module group and the stereo calibration block are located at different relative positions along the second platform coordinate axis of the platform coordinate system, and the first platform coordinate axis and the second platform coordinate axis are perpendicular to each other and are both perpendicular to a preset light projection plane of the three-dimensional line scanning module group.

[0072] Exemplarily, the platform coordinate axes of the platform coordinate system may include a first platform coordinate axis and a second platform coordinate axis that are perpendicular to each other. In the three-dimensional line scanning system, a preset light projection plane of the three-dimensional line scanning module group may be preset. The description of the preset light projection plane may be specifically referred to the above scheme, which will not be repeated here. The first platform coordinate axis and the second platform coordinate axis are both perpendicular to the preset light projection plane. The number of groups of point cloud data may be greater than or equal to two groups. For any one group of point cloud data in at least one group of point cloud data, when the three-dimensional line scanning module group collects the group of point cloud data, the three-dimensional line scanning module group and the stereo calibration block may move relative to each other along the straight line direction where the first platform coordinate axis is located. During the relative movement, the coordinates of the three-dimensional line scanning module group or the stereo calibration block on the first platform coordinate axis change, while the coordinates on the second platform coordinate axis remain unchanged. For any two groups of point cloud data in at least one group of point cloud data, the coordinates of the three-dimensional line scanning module on the second platform coordinate axis are different when collecting the two groups of point cloud data. In other words, in the process of collecting the two groups of point cloud data, the relative position of the three-dimensional line scanning module along the second platform coordinate axis of the platform coordinate system when collecting one group of point cloud data is different from the relative position of the three-dimensional line scanning module along the second platform coordinate axis of the platform coordinate system when collecting the other group of point cloud data.

[0073] The above technical solution collects two or more sets of point cloud data by scanning the stereo calibration block twice or twice, and can determine the deflection of the module coordinate system by integrating multiple sets of point cloud data. In addition, by controlling the relative position of the three-dimensional line scanning module and the stereo calibration block, it is possible to effectively avoid repeated scanning of the same position of the stereo calibration block, which is beneficial to scanning time and improves scanning efficiency.

[0074] Optionally, the number of at least one group of point cloud data is two groups, and the deflection angle of at least two target intersection lines around one or more module coordinate axes in the module coordinate system is determined according to the coordinates of at least part of the scanning points of the target intersection line segment, including: for each of the at least two target intersection lines, according to the coordinates of at least part of the scanning points of the target intersection line segment, determining a first distance in the first plane between the target intersection line segment corresponding to the first group of point cloud data and the target intersection line segment corresponding to the second group of point cloud data, so as to obtain a first distance corresponding to the at least two target intersection lines one by one; for each of the at least two target intersection lines, according to the coordinates of at least part of the scanning points of the target intersection line segment, determining a second distance in the first plane between the first intersection point corresponding to each target intersection line and the second intersection point, so as to obtain a first distance corresponding to the at least two target intersection lines one by one. The second distance, the first intersection point is the intersection point where any straight line parallel to the second module coordinate axis in the module coordinate system intersects with the target intersection line segment corresponding to the first group of point cloud data, and the second intersection point is the intersection point where the straight line intersects with the target intersection line segment corresponding to the second group of point cloud data; according to the first distance corresponding to at least two target intersection lines one by one and the second distance corresponding to at least two target intersection lines one by one, determine the deflection angle of at least two target intersection lines around the third module coordinate axis in the module coordinate system; wherein the first plane is a plane parallel to the first module coordinate axis and the second module coordinate axis in the module coordinate system, the first module coordinate axis, the second module coordinate axis and the third module coordinate axis correspond to the first platform coordinate axis, the second platform coordinate axis and the third platform coordinate axis of the platform coordinate system one by one, and the module coordinate system and the platform coordinate system are both spatial rectangular coordinate systems.

[0075] See also Fig.11 As shown, it is a schematic diagram of the target intersection line in the module coordinate system according to one embodiment of the present invention. Fig.11 In the embodiment shown, the target intersection line is Fig.10 The intersection line between plane ① and plane ② in the shown stereo calibration block (the intersection line of line segment a and line segment A) is parallel to the intersection line between plane ② and plane ③ (the intersection line of line segment b and line segment B). Correspondingly, the target intersection line segment includes line segment a, line segment b, line segment A and line segment B. In this stereo calibration block, the substrate can be regarded as a cuboid, the length direction of the substrate in the horizontal plane (the direction perpendicular to the target intersection line) is parallel to the first platform coordinate axis of the platform coordinate system, the width direction of the substrate in the horizontal plane (the direction parallel to the target intersection line) is parallel to the second platform coordinate axis of the platform coordinate system, and the height direction of the substrate in the vertical plane is parallel to the third platform coordinate axis of the platform coordinate system. Fig.11 In Fig.11 a is a schematic diagram of the position of the target intersection line segment in the module coordinate system. In the module coordinate system, the first module coordinate axis (in Fig.11The y-axis is shown in Figure 2) and corresponds to the first platform coordinate axis, and the second module coordinate axis (in Fig.11 The x-axis in FIG. 1 corresponds to the second platform coordinate axis, and the third module coordinate axis (in FIG. Fig.11 The coordinate plane formed by the first module coordinate axis and the second module coordinate axis is denoted as the first plane. Fig.11 In Fig.11 c is a schematic diagram of the projection of the target intersection line segment in the first plane. The projections of line segment a, line segment A, line segment b, and line segment B in the first plane are respectively Fig.11 c shows line segment a1, line segment A1, line segment b1, and line segment B1.

[0076] For example, the number of point cloud data can be two groups. Fig.10 and Fig.11As shown, the first set of point cloud data includes the coordinates of at least some of the scanned points on line segment a and the coordinates of at least some of the scanned points on line segment b, and the second set of point cloud data includes the coordinates of at least some of the scanned points on line segment A and the coordinates of at least some of the scanned points on line segment B. For the target intersection where line segment a and line segment A are located, the distance d2 between line segment a1 and line segment A1 can be calculated based on the coordinates of at least some of the scanned points on line segment a and the coordinates of at least some of the scanned points on line segment A. Similarly, for the target intersection where line segment b and line segment B are located, the distance d3 between line segment b1 and line segment B1 can be calculated based on the coordinates of at least some of the scanned points on line segment b and the coordinates of at least some of the scanned points on line segment B. More specifically, taking line segment a1 as an example, the coordinates of each scanning point on line segment a on the first module coordinate axis (y-axis) and the second module coordinate axis (x-axis) can be obtained in the first set of point cloud data. The coordinates of the two endpoints of line segment a1 are taken, and the tangent value (cotangent value) of the angle between line segment a1 and line segment l2 can be calculated according to the coordinate difference (absolute value) of the two endpoints on the first module coordinate axis and the coordinate difference (absolute value) on the second module coordinate axis. The length of line segment l2 can be calculated by the difference between the coordinates of any point on line segment a1 on the second module coordinate axis and the coordinates of the point on line segment A1 on the first module coordinate axis that is equal to the coordinates of the point on the first module coordinate axis. Alternatively, any straight line parallel to the coordinate axis of the second module and having intersections with both line segment a1 and line segment A1 can be obtained, and the intersection of the straight line with line segment a1 is recorded as the first intersection, and the intersection with line segment A1 is recorded as the second intersection. Then, the distance between the first intersection and the second intersection in the first plane is the length of line segment l2, and the length of line segment l2 can be used as the second distance corresponding to the target intersection of line segment a and line segment A. After obtaining the length of line segment l2 (the second distance) and the tangent value (cotangent value) of the angle between line segment l2 and line segment a1, the first distance d2 can be calculated based on geometric relationships (such as the Pythagorean theorem, trigonometric functions, etc.). It can be understood that the above process of obtaining the first distance d2 is only an example, and the embodiment of the present invention does not limit the specific method for obtaining the first distance d2. The method used can obtain the first distance d2. Similarly, the method for obtaining the length of line segment l3 is similar to the method for obtaining the length of line segment l2, that is, the method for calculating the second distance corresponding to the target intersection of line segment b and line segment B is similar to the method for calculating the second distance corresponding to the target intersection of line segment a and line segment A, and the method for calculating the first distance d3 is similar to the method for calculating the first distance d2, which will not be repeated here.

[0077] Exemplarily, according to the first distance and the second distance corresponding to the target intersection where line segment a and line segment A are located, and the first distance and the second distance corresponding to the target intersection where line segment b and line segment B are located, the deflection angle of the two target intersections deflected around the third module coordinate axis (z axis) can be calculated. In some embodiments, the ratio of the average value of the first distance of each target intersection to the average value of the second distance of each target intersection can be taken, and the ratio can be used as the sine value of the deflection angle of each target intersection deflected around the third module coordinate axis. In other embodiments, the average value of the ratio of the first distance to the second distance of each target intersection can be taken as the sine value of the deflection angle. It can be understood that the deflection angle of the deflection angle can be obtained according to the sine value of the deflection angle through the inverse sine function.

[0078] The above technical solution obtains the first distance and the second distance corresponding to the target intersection line in the first plane based on the coordinates of at least part of the scanning points of the target intersection line segment, so as to determine the deflection angle of the target intersection line around the module coordinate axis perpendicular to the first plane. This method can decompose the deflection of the target intersection line in three-dimensional space into the deflection within the plane, which is beneficial to reduce the calculation amount of the processor, and thus can improve the efficiency of the deflection angle calculation.

[0079] Optionally, the preset conditions include: the first target distance is less than or equal to the first distance threshold; or, the preset conditions include: the first target distance is less than or equal to the first distance threshold, or, the number of executions of the correction operation reaches a preset number threshold; wherein, the first target distance is the first distance corresponding to any target intersection line, or the first distance corresponding to all target intersection lines, or the average value of the first distances corresponding to at least some of the target intersection lines.

[0080] Exemplarily, a correction operation can be performed on the current point cloud data based on the obtained deflection angle of at least two target intersection lines around one or more module coordinate axes in the module coordinate system. Specifically, the corresponding sine value and / or cosine value can be calculated based on the deflection angle, and the coordinates of each point in the current point cloud data on each module coordinate axis can be recalculated based on the obtained sine value and / or cosine value to correct the point cloud data. After each correction operation is performed, new point cloud data can be obtained. After the scanning point of the target intersection line segment corresponding to the target intersection line is re-determined in the new point cloud data, the first distance corresponding to the target intersection line in the first plane can be recalculated based on at least part of the coordinates of the re-determined scanning point. The calculation method of the first distance can refer to the description of the above-mentioned scheme, which will not be repeated here. After obtaining the first distance of each target intersection line, any first distance among the multiple first distances can be selected as the first target distance, and the first target distance can be compared with the first distance threshold. Each first distance among the multiple first distances can also be used as the first target distance and compared with the first distance threshold. The average value of at least part of the first distances among the multiple first distances can also be calculated to obtain the first target distance, and the first target distance can be compared with the first distance threshold. When the first target distance is less than or equal to the first distance threshold, it can be determined that the preset condition is met. The first distance threshold can be defined according to actual conditions, and the embodiment of the present invention does not make specific restrictions on the first distance threshold. Alternatively, the preset condition may include a third preset condition or a second preset condition. The second preset condition is that the number of correction operations reaches the preset number threshold, and the third preset condition is that the first target distance is less than or equal to the first distance threshold. When any one of the second preset condition and the third preset condition is met, it can be determined that the preset condition is met.

[0081] The above technical solution determines whether the preset conditions are met through the first distance corresponding to the target intersection line, or the number of executions of the correction operation. The former is conducive to making the deflection angle of the calibrated module coordinate axis and the corresponding platform coordinate axis closer to 0°, and the latter can effectively save the time of invalid correction operations due to factors such as large errors in point cloud data or inaccurate calculation of deflection angles.

[0082] Optionally, the number of at least one group of point cloud data is two groups, and the deflection angle of at least two target intersection lines around one or more module coordinate axes in the module coordinate system is determined based on the coordinates of at least part of the scanning points of the target intersection line segment, including: for each of the at least two target intersection lines, according to the coordinates of at least part of the scanning points of the target intersection line segment, determining a third distance in the second plane between the target intersection line segment corresponding to the first group of point cloud data and the target intersection line segment corresponding to the second group of point cloud data, so as to obtain a third distance corresponding to the at least two target intersection lines one by one; for each of the at least two target intersection lines, according to the coordinates of at least part of the scanning points of the target intersection line segment, determining a fourth distance in the second plane between the first intersection point and the second intersection point corresponding to each target intersection line, so as to obtain a third distance corresponding to the at least two target intersection lines one by one. The fourth distance, the first intersection point is the intersection point where any straight line parallel to the second module coordinate axis in the module coordinate system intersects with the target intersection line segment corresponding to the first set of point cloud data, and the second intersection point is the intersection point where the straight line intersects with the target intersection line segment corresponding to the second set of point cloud data; according to the third distance corresponding to at least two target intersection lines one by one and the fourth distance corresponding to at least two target intersection lines one by one, the deflection angle of at least two target intersection lines around the first module coordinate axis in the module coordinate system is determined; wherein the second plane is a plane parallel to the second module coordinate axis and the third module coordinate axis in the module coordinate system, the first module coordinate axis, the second module coordinate axis and the third module coordinate axis correspond to the first platform coordinate axis, the second platform coordinate axis and the third platform coordinate axis of the platform coordinate system one by one, and the module coordinate system and the platform coordinate system are both spatial rectangular coordinate systems.

[0083] Please continue reading Fig.10 and Fig.11 As shown, the coordinate plane formed by the second module coordinate axis and the third module coordinate axis is recorded as the second plane. Fig.11 In Fig.11 b is a schematic diagram of the projection of the target intersection line segment in the second plane. The projections of line segment a, line segment A, line segment b, and line segment B in the second plane are respectively Fig.11 b shows line segment a1, line segment A12, line segment b1, and line segment B1. Fig.11b, for the target intersection where line segment a and line segment A are located, the distance d1 between line segment a1 and line segment A1 can be calculated based on the coordinates of at least some of the scanned points on line segment a and the coordinates of at least some of the scanned points on line segment A. Alternatively, for the target intersection where line segment b and line segment B are located, the distance between line segment b1 and line segment B1 can be calculated based on the coordinates of at least some of the scanned points on line segment b and the coordinates of at least some of the scanned points on line segment B, and this distance can also be used as d1. More specifically, taking line segment a1 as an example, the coordinates of each scanning point on line segment a on the second module coordinate axis (x-axis) and the third module coordinate axis (z-axis) can be obtained in the first set of point cloud data. The coordinates of the two endpoints of line segment a1 are taken, and the tangent value (cotangent value) of the angle between line segment a1 and line segment l1 can be calculated according to the coordinate difference (absolute value) of the two endpoints on the second module coordinate axis and the coordinate difference (absolute value) on the third module coordinate axis. The length of line segment l1 is the distance difference between the three-dimensional line scanning module when collecting the first set of point cloud data and the second set of point cloud data on the second platform coordinate axis, that is, the distance of relative movement between the three-dimensional line scanning module and the stereo calibration block along the second platform coordinate axis after obtaining the first set of point cloud data and before starting to collect the second set of point cloud data. The distance can be defined according to the actual situation, and it is greater than or equal to the scanning line length. The length of line segment l1 can be calculated by the difference between the coordinates of any point of line segment a1 on the second module coordinate axis and the coordinates of a point on the second module coordinate axis whose coordinates on line segment A1 on the three-module coordinate system are equal to the coordinates of the point on the third module coordinate axis. Alternatively, any straight line in the second plane that is parallel to the second module coordinate system and has intersections with line segment a1 and line segment A1 can be obtained, and the intersection of the straight line with line segment a1 is recorded as the first intersection, and the intersection with line segment A1 is recorded as the second intersection. Then, the distance between the first intersection and the second intersection in the second plane is the length of line segment l1, and the length of line segment l1 can be used as the third distance corresponding to the target intersection where line segment a and line segment A are located. After obtaining the length of line segment l1 (fourth distance) and the tangent value (cotangent value) of the angle between line segment l1 and line segment a1, the third distance d1 can be calculated based on geometric relationships (such as the Pythagorean theorem, trigonometric functions, etc.). It can be understood that the above process of obtaining the third distance d1 is only an example. The embodiment of the present invention does not limit the specific method for obtaining the third distance d1. The method used can obtain the third distance d1. Similarly, the calculation method of the third distance and the fourth distance corresponding to the target intersection where line segment b and line segment B are located is similar to the calculation method of the third distance and the fourth distance corresponding to the target intersection where line segment a and line segment A are located, and they are not repeated here. According to the third distance and the fourth distance corresponding to the target intersection where line segment a and line segment A are located, and the third distance and the fourth distance corresponding to the target intersection where line segment b and line segment B are located, the deflection angle of the two target intersections around the first module coordinate system (y-axis) can be calculated.

[0084] Exemplarily, according to the third distance and the fourth distance corresponding to the target intersection where line segment a and line segment A are located, and the third distance and the fourth distance corresponding to the target intersection where line segment b and line segment B are located, the deflection angle of the two target intersections deflected around the first module coordinate axis (y axis) can be calculated. In some embodiments, the ratio of the average value of the third distance of each target intersection to the average value of the fourth distance of each target intersection can be taken, and the ratio can be used as the sine value of the deflection angle of each target intersection deflected around the first module coordinate axis. In other embodiments, the average value of the ratio of the third distance to the fourth distance of each target intersection can be taken as the sine value of the deflection angle. Alternatively, a third distance can be arbitrarily selected from a plurality of third distances, and the fourth distance corresponding to the target intersection corresponding to the third distance is obtained, and the ratio of the third distance to the fourth distance is taken as the sine value of the deflection angle. It can be understood that the deflection angle of the deflection angle can be obtained according to the sine value of the deflection angle through the inverse sine function.

[0085] The above technical solution obtains the third distance and the fourth distance corresponding to the target intersection line in the second plane based on the coordinates of at least part of the scanning points of the target intersection line segment, so as to determine the deflection angle of the target intersection line around the module coordinate axis perpendicular to the second plane. This method can decompose the deflection of the target intersection line in three-dimensional space into the deflection within the plane, which is beneficial to reduce the calculation amount of the processor, and thus can improve the efficiency of the deflection angle calculation.

[0086] Optionally, the preset conditions include: the second target distance is less than or equal to the second distance threshold; or, the preset conditions include: the second target distance is less than or equal to the second distance threshold, or, the number of executions of the correction operation reaches a preset number threshold; wherein, the second target distance is the third distance corresponding to any target intersection line, or the third distance corresponding to all target intersection lines, or the average value of the third distances corresponding to at least some of the target intersection lines.

[0087] Exemplarily, after each correction operation is performed, new point cloud data can be obtained. After the scanning point of the target intersection line segment corresponding to the target intersection line is re-determined in the new point cloud data, the third distance corresponding to the target intersection line in the second plane can be recalculated according to at least part of the coordinates of the re-determined scanning point. The calculation method of the third distance can refer to the description of the above scheme, which will not be repeated here. Similarly, after obtaining the third distance of each target intersection line, any third distance in a plurality of third distances can be selected as the second target distance, and the second target distance can be compared with the second distance threshold. Each third distance in a plurality of third distances can also be used as the second target distance and compared with the second distance threshold. The average value of at least part of the third distances in a plurality of third distances can also be calculated to obtain the second target distance, and the second target distance can be compared with the second distance threshold. When the second target distance is less than or equal to the second distance threshold, it can be determined that the preset condition is met. The second distance threshold can be defined according to actual conditions, and the embodiment of the present invention does not make specific restrictions on the second distance threshold. Alternatively, the preset condition can include a fourth preset condition or a second preset condition. The second preset condition is that the number of correction operations reaches the preset number threshold, and the fourth preset condition is that the second target distance is less than or equal to the second distance threshold. When any one of the second preset condition and the fourth preset condition is met, it can be determined that the preset condition is met.

[0088] The above technical solution determines whether the preset conditions are met through the third distance corresponding to the target intersection line, or the number of executions of the correction operation. The former is conducive to making the deflection angle of the calibrated module coordinate axis and the corresponding platform coordinate axis closer to 0°, and the latter can effectively save the time of invalid correction operations due to factors such as large errors in point cloud data or inaccurate calculation of deflection angles.

[0089] Optionally, according to the deflection angle of at least two target intersection lines around one or more module coordinate axes in the module coordinate system, the current at least two groups of point cloud data are corrected, including: for the coordinates of each scanning point in the at least two groups of point cloud data, based on the deflection angle of at least two target intersection lines around the third module coordinate axis in the module coordinate system, the coordinates of the scanning point on the first module coordinate axis in the module coordinate system before correction, and the coordinates of the scanning point on the second module coordinate axis in the module coordinate system before correction, determining the corrected coordinates of the scanning point on the first module coordinate axis; based on the deflection angle of at least two target intersection lines around the first module coordinate axis, the coordinates of the scanning point on the second module coordinate axis before correction, and the coordinates of the scanning point on the third module coordinate axis before correction. Coordinates, determine the corrected coordinates of the scanning point on the third module coordinate axis; determine the corrected coordinates of the scanning point on the second module coordinate axis based on the deflection angle of at least two target intersection lines around the third module coordinate axis and the coordinates of the scanning point on the second module coordinate axis before correction, or, determine the corrected coordinates of the scanning point on the second module coordinate axis based on the deflection angle of at least two target intersection lines around the first module coordinate axis, the coordinates of the scanning point on the second module coordinate axis before correction, and the coordinates of the scanning point on the third module coordinate axis before correction; wherein the first module coordinate axis and the third module coordinate axis correspond to the first platform coordinate axis and the third platform coordinate axis of the platform coordinate system, respectively, and the module coordinate system and the platform coordinate system are both spatial rectangular coordinate systems.

[0090] For example, for the coordinates of each scanning point in at least two sets of point cloud data, the corrected coordinates (X, Y, Z) of the scanning point can be obtained by the following formulas (7)(8)(9)(10):

[0091] X=x*cosα (7)

[0092] Y=y+x*sinα (8)

[0093] X=x*cosβ+z*sinβ (9)

[0094] Z=z* cosβ-x*sinβ (10)

[0095] Among them, (x, y, z) represents the coordinates of the scanning point before correction, α represents the deflection angle of at least two target intersection lines around the third module coordinate axis in the module coordinate system, and β represents the deflection angle of at least two target intersection lines around the first module coordinate axis in the module coordinate system; wherein the first module coordinate axis and the third module coordinate axis correspond to the first platform coordinate axis and the third platform coordinate axis of the platform coordinate system respectively, and the module coordinate system and the platform coordinate system are both spatial rectangular coordinate systems.

[0096] Please continue reading Fig.10 and Fig.11 As shown, in Fig.11 In the embodiment shown, the deflection angle α of the target intersection line where line segment a and line segment A are located and the target intersection line where line segments b and B are located around the third module coordinate axis is equal to Fig.11 The angles between line segments a1, A1, b1 and B1 and the x-axis in c are α=arcsin[(d2+d3) / (2*l2)], or α=arcsin[(d2+d3) / (l3+l2)], or α=arcsin(d2 / l2+d3 / l3), or α=(arcsin(d2 / l2)+arcsin(d3 / l3)) / 2, where d2 is the first distance corresponding to the target intersection line between line segment a and line segment A, d3 is the first distance corresponding to the target intersection line between line segment b and line segment B, l2 is the second distance corresponding to the target intersection line between line segment a and line segment A, and l3 is the second distance corresponding to the target intersection line between line segment b and line segment B. The method for obtaining the first distance and the second distance can refer to the above scheme and will not be repeated here. In the first plane, the coordinate y of the scanning point (x, y, z) in the first module coordinate system and the coordinate x in the second module coordinate system can be corrected by using formula (7) and formula (8) to obtain Y and X. Similarly, the deflection angle β of the target intersection line where line segment a and line segment A are located and the target intersection line where line segment b and B are located around the first module coordinate axis is equal to Fig.11 The angle between line segments a1, A1, b1 and B1 and the x-axis in b is β=arcsin(d1 / l1). Wherein, d1 is the third distance corresponding to the target intersection line where line segment a and line segment A are located, and l1 is the fourth distance corresponding to the target intersection line where line segment a and line segment A are located. For example, line length l1=8mm, d1=1mm, then β=arcsin(1 / 8)≈7.2°. The method for obtaining the third distance and the fourth distance can refer to the above scheme, which will not be repeated here. It can be understood that the calculation method of the β value is not limited to the above formula. Similar to the α value, it can be calculated and obtained based on any target intersection line, or it can be calculated and obtained based on two target intersection lines, which will not be repeated here. In the second plane, the coordinate x of the scanning point (x, y, z) in the second module coordinate system and the coordinate z in the third module coordinate system can be corrected to obtain X and Z using formulas (9) and (10).

[0097] Exemplarily, in the first plane and the second plane, two corrected coordinate values ​​of the scanning point on the second module coordinate axis can be obtained (see formula (7) and formula (9)), and the coordinate value obtained by using formula (7) is recorded as X1, and the coordinate value obtained by using formula (9) is recorded as X2. For each scanning point, the coordinates obtained by correcting the scanning point include (X1, Y, Z) and (X2, Y, Z). After each correction operation, (X1, Y, Z) can be used as the corrected coordinates of the scanning point, or (X2, Y, Z) can be used as the corrected coordinates of the scanning point, or (0.5*(X1+X2), Y, Z) can be used as the corrected coordinates of the scanning point. It can be understood that formulas (7)(8)(9)(10) can correct the coordinates of any point in the module coordinate system to obtain corrected point cloud data. After each calibration operation, the scanning points on the target intersection line segment can be re-determined. When the preset conditions (see the above solution description, which will not be repeated here) are met, the corrected point cloud data obtained by the current calibration operation can be saved to establish the conversion relationship between the module coordinate system and the platform coordinate system. When the preset conditions are not met, the re-determined scanning points are calibrated again using formulas (7)(8)(9)(10) until the preset conditions are met.

[0098] In some embodiments, the first set of corrected point cloud data can be obtained by using formula (7), (8), (10), the second set of corrected point cloud data can be obtained by using formula (8), (9), (10), and the scanning points on the target intersection line segment can be re-determined based on the first set of corrected point cloud data, and the scanning points on the target intersection line segment can be re-determined based on the second set of corrected point cloud data. When all the preset conditions are met, the point cloud data with the smallest deflection angle of at least two target intersection lines around the third module coordinate axis / first module coordinate axis can be saved to establish the conversion relationship between the module coordinate system and the platform coordinate system. The point cloud data with the smallest sum of the deflection angle of at least two target intersection lines around the first module coordinate axis and the deflection angle around the third module coordinate axis can also be saved to establish the module coordinate system. When there is only one set of corrected point cloud data that meets the preset conditions, the point cloud data that meets the preset conditions is saved to establish the conversion relationship between the module coordinate system and the platform coordinate system. When both sets of corrected point cloud data do not meet the preset conditions, the point cloud data with the smallest deflection angle of at least two target intersection lines around the third module coordinate axis / first module coordinate axis, or the point cloud data with the smallest sum of the deflection angle of at least two target intersection lines around the first module coordinate axis and the deflection angle around the third module coordinate axis can be selected. The scanning points on the target intersection line segments are re-determined based on the selected point cloud data, and the re-determined scanning points are again corrected using formulas (7)(8)(9)(10) until the preset conditions are met.

[0099] The above technical solution converts the three-dimensional module coordinate system into a two-dimensional plane coordinate system, which can make the obtained deflection angle more intuitive and easier to obtain. The plane geometric relationship is used in each plane coordinate system to obtain the deflection of the target intersection line around each module coordinate axis, which is conducive to simplifying the calculation process of the processor and can quickly and accurately complete the calibration of the module coordinate system.

[0100] According to another aspect of the present invention, a stereoscopic calibration block is provided. The stereoscopic calibration block has at least three calibration planes intersecting in pairs, each calibration plane is a plane, and intersection lines of every two intersecting calibration planes in the at least three calibration planes are parallel to each other.

[0101] For example, the stereo calibration block may have multiple planes, and two adjacent planes may intersect and have an intersection line. Among the multiple planes of the stereo calibration block, there is at least one plane with two mutually parallel intersection lines. This plane is the calibration plane, and two planes that intersect with the plane and have one of the two mutually parallel intersection lines may be the calibration plane. Please continue to refer to Fig.10 As shown, Fig.10 The stereo calibration block shown has three calibration planes, namely plane ①, plane ② and plane ③. The intersection line between plane ① and plane ② (the intersection line of line segment a and line segment A) and the intersection line between plane ② and plane ③ (the intersection line of line segment b and line segment B) are parallel to each other.

[0102] According to the stereo calibration block of the embodiment of the present invention, it satisfies that there are at least three calibration planes intersecting with each other, and the intersection lines of every two intersecting calibration planes are parallel to each other. The processing accuracy requirement for the stereo calibration block is relatively low, which effectively saves costs.

[0103] Optionally, the three-dimensional calibration block includes a substrate and at least one identification block arranged on the upper surface of the substrate, each identification block is a right quadrangular prism with a trapezoidal bottom surface, the bottom surface of each identification block is perpendicular to the upper surface of the substrate and the lower base edge of the bottom surface of each identification block is in contact with the upper surface of the substrate, and at least three calibration planes include the upper surface of the substrate and at least part of the side surface of at least part of the identification blocks in at least one identification block.

[0104] Please continue reading Fig.10 As shown, the three-dimensional plate can be composed of a substrate and one or more identification blocks arranged on the upper surface of the substrate (in Fig. 9The number of identification blocks is 2). Each identification block can be a right quadrangular prism with a trapezoidal bottom surface, and the dimensions of the trapezoidal bottom surfaces of the identification blocks (including the upper base, lower base and height) can be the same or different. For each identification block, the bottom surface of the identification block is perpendicular to the upper surface of the substrate, and the lower base edge of the bottom surface of the identification block (the longer side of the parallel sides of the trapezoid) is attached to the upper surface of the substrate, and the side surface of the identification block including the lower base edge is attached to the upper surface of the substrate. In the three-dimensional calibration block, the calibration plane can at least include: the upper surface of the substrate, at least part of the side surface of one or more identification blocks among all the included identification blocks. Fig.10 In the figure, plane ① belongs to the upper surface of the substrate, and plane ② and plane ③ belong to two adjacent side surfaces of one of the two identification blocks.

[0105] The three-dimensional calibration block according to the embodiment of the present invention may include a substrate and one or more identification blocks arranged on the upper surface of the substrate. The structure is simple, easy to process and has high processing flexibility. The number of calibration planes can be set according to actual needs. In addition, the intersection line of the three-dimensional calibration block is relatively obvious in the structure, and it is easier to accurately obtain its point cloud data, which is suitable for the calibration of the coordinate system of the three-dimensional line scanning system using line measurement.

[0106] See also Fig.12 As shown, it is a schematic diagram of the structure of a coordinate system calibration device for a three-dimensional line scanning system according to an embodiment of the present invention. According to another aspect of the present invention, a coordinate system calibration device 1200 for a three-dimensional line scanning system is also provided. The three-dimensional line scanning system includes a three-dimensional line scanning module and a transportation control platform. The transportation control platform is provided with a three-dimensional line scanning module and / or a stereo calibration block. The transportation control platform is used to control the relative movement between the three-dimensional line scanning module and the stereo calibration block. The three-dimensional line scanning module has a module coordinate system, and the transportation control platform has a platform coordinate system. The module coordinate axes of the module coordinate system correspond to the platform coordinate axes of the platform coordinate system one by one. The stereo calibration block has at least three calibration planes intersecting with each other. The intersection lines of each two intersecting calibration planes in the at least three calibration planes are parallel to each other. The device 1200 includes:

[0107] The acquisition module 1210 is used to acquire at least one set of point cloud data collected by the three-dimensional line scanning module for performing three-dimensional line scanning on the stereo calibration block, each set of point cloud data is collected by the three-dimensional line scanning module during the relative movement of the three-dimensional line scanning module and the stereo calibration block along the first platform coordinate axis in the platform coordinate system, and each set of point cloud data includes the coordinates of each scan point collected in the module coordinate system;

[0108] A first determination module 1220 is used to determine, for each of at least two target intersection lines of at least three calibration planes, a scanning point on a target intersection line segment corresponding to each set of point cloud data according to at least one set of point cloud data, where the target intersection line segment is a line segment on the target intersection line;

[0109] The second determination module 1230 is used to determine the conversion relationship between the module coordinate system and the platform coordinate system according to the coordinates of at least part of the scanning points of the target intersection line segment.

[0110] According to another aspect of the present invention, a storage medium is also provided, on which program instructions are stored, and when the program instructions are executed by a computer or a processor, the computer or the processor executes the corresponding steps of the coordinate system calibration method of the above-mentioned three-dimensional line scanning system according to the embodiment of the present invention, and is used to implement the corresponding modules in the control device of the above-mentioned three-dimensional line scanning system according to the embodiment of the present invention or the corresponding modules in the control device for the three-dimensional line scanning system. The storage medium may include, for example, a memory card of a smart phone, a storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disk read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0111] According to yet another aspect of the present invention, there is provided a computer program product, comprising computer program instructions, which are used to execute the coordinate system calibration method of the three-dimensional line scan system as described above when the computer program instructions are run.

[0112] A person skilled in the art can understand the specific implementation and beneficial effects of the control device of the three-dimensional line scanning system by reading the above-mentioned specific description of the coordinate system calibration method of the three-dimensional line scanning system. For the sake of brevity, it will not be repeated here.

[0113] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present invention thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the present invention. All such changes and modifications are intended to be included within the scope of the present invention as required by the appended claims.

[0114] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0115] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0116] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0117] Similarly, it should be understood that in order to streamline the present invention and help understand one or more of the various inventive aspects, in the description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present invention should not be interpreted as reflecting the following intention: the claimed invention requires more features than the features explicitly stated in each claim. More specifically, as reflected in the corresponding claims, the inventive point is that the corresponding technical problem can be solved with less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present invention.

[0118] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0119] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present invention and form different embodiments. For example, in the claims, any one of the claimed embodiments may be used in any combination.

[0120] The various component embodiments of the present invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. Those skilled in the art will appreciate that a microprocessor or digital signal processor (DSP) may be used in practice to implement some or all of the functions of some modules in a control device for a three-dimensional line scanning system according to an embodiment of the present invention. The present invention may also be implemented as a device program (e.g., a computer program and a computer program product) for executing part or all of the methods described herein. Such a program for implementing the present invention may be stored on a computer-readable medium, or may be in the form of one or more signals. Such a signal may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0121] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc., does not indicate any order. These words may be interpreted as names.

[0122] The above is only a specific embodiment or description of a specific embodiment of the present invention, and the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A coordinate system calibration method for a three-dimensional line scanning system, characterized in that: The three-dimensional line scanning system comprises a three-dimensional line scanning module and a transport control platform, the three-dimensional line scanning module and / or a stereo calibration block are arranged on the transport control platform, the transport control platform is used to control the relative movement between the three-dimensional line scanning module and the stereo calibration block, the three-dimensional line scanning module has a module coordinate system, the transport control platform has a platform coordinate system, the module coordinate axes of the module coordinate system correspond to the platform coordinate axes of the platform coordinate system one by one, the stereo calibration block has at least three calibration planes intersecting with each other, and the intersection lines of each two intersecting calibration planes in the at least three calibration planes are parallel to each other, and the method comprises: Acquire at least one set of point cloud data collected by the three-dimensional line scanning module group when performing three-dimensional line scanning on the three-dimensional calibration block, each set of point cloud data is collected by the three-dimensional line scanning module group during the relative movement of the three-dimensional line scanning module group and the three-dimensional calibration block along the first platform coordinate axis in the platform coordinate system, and each set of point cloud data includes the coordinates of each collected scanning point in the module coordinate system; For each of the at least two target intersection lines of the at least three calibration planes, determining a scanning point on a target intersection line segment corresponding to each set of point cloud data according to the at least one set of point cloud data, the target intersection line segment being a line segment on the target intersection line; The conversion relationship between the module coordinate system and the platform coordinate system is determined according to the coordinates of at least part of the scanning points of the target intersection line segment.

2. The method according to claim 1, characterized in that The intersection lines of every two intersecting calibration planes in the at least three calibration planes are parallel to the second platform coordinate axis in the platform coordinate system, and the first platform coordinate axis and the second platform coordinate axis are perpendicular to each other and perpendicular to the preset light projection plane of the three-dimensional line scanning module; The determining the conversion relationship between the module coordinate system and the platform coordinate system according to the coordinates of at least part of the scanning points of the target intersection line segment includes: Correction operation: determining the deflection angle of the at least two target intersection lines around one or more module coordinate axes in the module coordinate system according to the coordinates of at least part of the scanning points of the target intersection line segment; and correcting the current at least one set of point cloud data according to the deflection angle of the at least two target intersection lines around one or more module coordinate axes in the module coordinate system; If the preset condition is not satisfied, for each of the at least two target intersection lines, determining the scanning point on the target intersection line segment corresponding to each set of point cloud data according to the at least one set of corrected point cloud data, and returning to perform the correction operation; If the preset condition is satisfied, the conversion relationship is determined according to the at least one set of point cloud data after correction and the at least one set of point cloud data before the first correction operation is performed.

3. The method according to claim 2, characterized in that The preset condition includes: the deflection angle of the at least two target intersection lines around the one or more module coordinate axes meets the preset angle requirement; or, The preset conditions include: the deflection angle of the at least two target intersection lines around the one or more module coordinate axes meets the preset angle requirement, or the number of executions of the correction operation reaches a preset number threshold.

4. The method according to any one of claims 1 to 3, characterized in that: The number of the at least one group of point cloud data is two or more than two groups. When collecting any two different groups of point cloud data, the three-dimensional line scanning module group and the stereo calibration block are located at different relative positions along the second platform coordinate axis of the platform coordinate system, and the first platform coordinate axis and the second platform coordinate axis are perpendicular to each other and are both perpendicular to the preset light projection plane of the three-dimensional line scanning module group.

5. The method according to claim 4 as dependent on claim 2, characterized in that The number of the at least one set of point cloud data is two sets, and the determining, based on the coordinates of at least part of the scanning points of the target intersection line segment, the deflection angle of the at least two target intersection lines around one or more module coordinate axes in the module coordinate system comprises: For each of the at least two target intersection lines, determining a first distance between a target intersection line segment corresponding to the first set of point cloud data and a target intersection line segment corresponding to the second set of point cloud data in the first plane according to coordinates of at least part of the scanning points of the target intersection line segment, so as to obtain a first distance corresponding to the at least two target intersection lines one by one; For each of the at least two target intersection lines, determine a second distance between a first intersection point and a second intersection point corresponding to each target intersection line in the first plane according to the coordinates of at least part of the scanning points of the target intersection line segment, so as to obtain a second distance corresponding to the at least two target intersection lines one by one, wherein the first intersection point is an intersection point where any straight line parallel to the second module coordinate axis in the module coordinate system intersects with the target intersection line segment corresponding to the first set of point cloud data, and the second intersection point is an intersection point where the straight line intersects with the target intersection line segment corresponding to the second set of point cloud data; Determine a deflection angle of the at least two target intersection lines around a third module coordinate axis in the module coordinate system according to first distances corresponding to the at least two target intersection lines one by one and second distances corresponding to the at least two target intersection lines one by one; Among them, the first plane is a plane parallel to the first module coordinate axis and the second module coordinate axis in the module coordinate system, the first module coordinate axis, the second module coordinate axis and the third module coordinate axis correspond one by one to the first platform coordinate axis, the second platform coordinate axis and the third platform coordinate axis of the platform coordinate system, and the module coordinate system and the platform coordinate system are both spatial rectangular coordinate systems.

6. The method according to claim 5, characterized in that The preset condition includes: the first target distance is less than or equal to the first distance threshold; or, The preset conditions include: the first target distance is less than or equal to the first distance threshold, or the number of executions of the correction operation reaches a preset number threshold; The first target distance is the first distance corresponding to any target intersection line, or the first distance corresponding to all target intersection lines, or the average value of the first distances corresponding to at least some target intersection lines.

7. The method according to claim 4 as dependent on claim 2, characterized in that The number of the at least one set of point cloud data is two sets, and the determining, based on the coordinates of at least part of the scanning points of the target intersection line segment, the deflection angle of the at least two target intersection lines around one or more module coordinate axes in the module coordinate system comprises: For each of the at least two target intersection lines, determining a third distance between the target intersection line segment corresponding to the first set of point cloud data and the target intersection line segment corresponding to the second set of point cloud data in the second plane according to the coordinates of at least part of the scanning points of the target intersection line segment, so as to obtain a third distance corresponding to the at least two target intersection lines one by one; For each of the at least two target intersection lines, determine a fourth distance between a first intersection point and a second intersection point corresponding to each target intersection line in the second plane according to the coordinates of at least part of the scanning points of the target intersection line segment, so as to obtain a fourth distance corresponding to the at least two target intersection lines one by one, wherein the first intersection point is an intersection point where any straight line parallel to the second module coordinate axis in the module coordinate system intersects with the target intersection line segment corresponding to the first set of point cloud data, and the second intersection point is an intersection point where the straight line intersects with the target intersection line segment corresponding to the second set of point cloud data; Determine a deflection angle of the at least two target intersection lines around a first module coordinate axis in the module coordinate system according to a third distance corresponding to the at least two target intersection lines one by one and a fourth distance corresponding to the at least two target intersection lines one by one; Among them, the second plane is a plane parallel to the second module coordinate axis and the third module coordinate axis in the module coordinate system, the first module coordinate axis, the second module coordinate axis and the third module coordinate axis correspond one-to-one with the first platform coordinate axis, the second platform coordinate axis and the third platform coordinate axis of the platform coordinate system, and the module coordinate system and the platform coordinate system are both spatial rectangular coordinate systems.

8. The method according to claim 7, characterized in that The preset condition includes: the second target distance is less than or equal to the second distance threshold; or, The preset conditions include: the second target distance is less than or equal to the second distance threshold, or the number of executions of the correction operation reaches a preset number threshold; The second target distance is the third distance corresponding to any target intersection line, or the third distance corresponding to all target intersection lines, or the average value of the third distances corresponding to at least some target intersection lines.

9. The method according to claim 2 or 3, characterized in that: The step of correcting the at least two sets of current point cloud data according to the deflection angles of the at least two target intersection lines around one or more module coordinate axes in the module coordinate system comprises: For the coordinates of each scanning point in the at least two sets of point cloud data, Determine the corrected coordinates of the scanning point on the first module coordinate axis based on the deflection angle of the at least two target intersection lines around the third module coordinate axis in the module coordinate system, the pre-corrected coordinates of the scanning point on the first module coordinate axis in the module coordinate system, and the pre-corrected coordinates of the scanning point on the second module coordinate axis in the module coordinate system; Determine the corrected coordinates of the scanning point on the third module coordinate axis based on the deflection angle of the at least two target intersection lines around the first module coordinate axis, the coordinates of the scanning point on the second module coordinate axis before correction, and the coordinates of the scanning point on the third module coordinate axis before correction; Determine the corrected coordinates of the scanning point on the second module coordinate axis based on the deflection angle of the at least two target intersection lines around the third module coordinate axis and the coordinates of the scanning point on the second module coordinate axis before correction, or determine the corrected coordinates of the scanning point on the second module coordinate axis based on the deflection angle of the at least two target intersection lines around the first module coordinate axis, the coordinates of the scanning point on the second module coordinate axis before correction, and the coordinates of the scanning point on the third module coordinate axis before correction; The first module coordinate axis and the third module coordinate axis correspond to the first platform coordinate axis and the third platform coordinate axis of the platform coordinate system respectively, and both the module coordinate system and the platform coordinate system are spatial rectangular coordinate systems.

10. A three-dimensional calibration block, characterized in that: The three-dimensional calibration block has at least three calibration planes intersecting in pairs, each calibration plane is a plane, and intersection lines of every two intersecting calibration planes in the at least three calibration planes are parallel to each other.

11. The three-dimensional calibration block according to claim 10, characterized in that: The three-dimensional calibration block includes a substrate and at least one identification block arranged on the upper surface of the substrate, each identification block is a right quadrangular prism with a trapezoidal bottom surface, the bottom surface of each identification block is perpendicular to the upper surface of the substrate, and the lower bottom edge of the bottom surface of each identification block is in contact with the upper surface of the substrate, The at least three calibration planes include an upper surface of the substrate and at least part of side surfaces of at least part of the at least one identification block.

12. A coordinate system calibration device for a three-dimensional line scanning system, characterized in that: The three-dimensional line scanning system comprises a three-dimensional line scanning module and a transport control platform, the three-dimensional line scanning module and / or a three-dimensional calibration block are arranged on the transport control platform, the transport control platform is used to control the relative movement between the three-dimensional line scanning module and the three-dimensional calibration block, the three-dimensional line scanning module has a module coordinate system, the transport control platform has a platform coordinate system, the module coordinate axes of the module coordinate system correspond one-to-one to the platform coordinate axes of the platform coordinate system, the three-dimensional calibration block has at least three calibration planes intersecting with each other, and the intersection lines of each two intersecting calibration planes in the at least three calibration planes are parallel to each other, and the device comprises: an acquisition module, used for acquiring at least one set of point cloud data collected by the three-dimensional line scanning module group when performing three-dimensional line scanning on the three-dimensional calibration block, each set of point cloud data is collected by the three-dimensional line scanning module group during the relative movement of the three-dimensional line scanning module group and the three-dimensional calibration block along the first platform coordinate axis in the platform coordinate system, and each set of point cloud data includes the coordinates of each scan point collected in the module coordinate system; A first determination module is used to determine, for each of the at least two target intersection lines of the at least three calibration planes, a scanning point on a target intersection line segment corresponding to each set of point cloud data according to the at least one set of point cloud data, wherein the target intersection line segment is a line segment on the target intersection line; The second determination module is used to determine the conversion relationship between the module coordinate system and the platform coordinate system according to the coordinates of at least part of the scanning points of the target intersection line segment.

13. A storage medium having program instructions stored thereon, characterized in that: The program instructions are used to execute the coordinate system calibration method of the three-dimensional line scanning system as described in any one of claims 1-9 when running.

14. A computer program product comprising computer program instructions, characterized in that The computer program instructions are used to execute the coordinate system calibration method of the three-dimensional line scanning system as described in any one of claims 1-9 when running.

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