Intersection Error Detection Method and System for Elevation Axis and Azimuth Axis of Laser Tracker

Abstract

The present invention provides a method and system for detecting the intersection error between the pitch axis and the azimuth axis of a laser tracker. The method includes: respectively arranging a first inspection rod and a second inspection rod at both ends of the pitch axis, wherein the first inspection rod and the second inspection rod are rotating bodies with a generatrix and an axis, the generatrix is a straight line, and the axis coincides with the central axis of the pitch axis; rotating the azimuth axis, and respectively obtaining the shadow patterns of the first inspection rod and the second inspection rod under the illumination of parallel light, wherein the illumination direction of the parallel light is parallel to the axis of the azimuth axis, and the shadow patterns are presented on a first receiving plane; determining the axial distance between the first inspection rod and the second inspection rod according to the shadow patterns; and determining the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the axial distance between the first inspection rod and the second inspection rod. The method of the present invention has a simple measurement process and high measurement accuracy, and can meet the requirements for high-precision detection of the intersection error of the axis system of the laser tracker.

Description

Technical Field

[0001] The present invention relates to the technical field of spatial coordinate measuring instruments, and particularly to a method and system for detecting the intersection error between the pitch axis and the azimuth axis of a laser tracker. Background Art

[0002] As a spatial coordinate measuring instrument, the laser tracker has a wide range of applications in the fields of aerospace, shipbuilding, rail transit, etc.

[0003] In the geometric structure of the laser tracker, the pitch axis and the azimuth axis are the key axis systems of the laser tracker. The azimuth axis can carry a mirror and rotate on a horizontal plane, and the pitch axis can make the mirror rotate on a vertical plane. The combined action of the two enables the laser tracker to perform three-dimensional rotation in the measurement space. In an ideal situation, the azimuth axis and the pitch axis of the laser tracker should intersect. However, due to machining and alignment errors in the mechanical structure, the pitch axis and the azimuth axis do not intersect, that is, there is a certain distance between the pitch axis and the azimuth axis in space. This distance value is called the intersection error between the pitch axis and the azimuth axis. This error causes the laser tracker beam to deviate from the ideal position, thereby generating measurement errors. Therefore, it is necessary to study high-precision detection means to detect the intersection error between the pitch axis and the azimuth axis of the laser tracker, so as to facilitate the precise adjustment and error correction of the laser tracker axis system. Summary of the Invention

[0004] In view of the above problems, the present invention proposes a method and system for detecting the intersection error between the pitch axis and the azimuth axis of a laser tracker, which can detect the intersection error between the pitch axis and the azimuth axis of the laser tracker with high precision by using a simple operation process, and can meet the requirements of high-precision detection.

[0005] As an aspect of the present invention, the method for detecting the intersection error between the pitch axis and the azimuth axis of a laser tracker proposed by the present invention includes: respectively setting a first inspection rod and a second inspection rod at both ends of the pitch axis, wherein the first inspection rod and the second inspection rod are rotating bodies with a generatrix and an axis, the generatrix is a straight line, and the axis coincides with the central axis of the pitch axis; rotating the azimuth axis, and respectively obtaining the shadow patterns of the first inspection rod and the second inspection rod under the illumination of parallel light, wherein the illumination direction of the parallel light is parallel to the axis of the azimuth axis, and the shadow patterns are presented on a first receiving plane; determining the axis spacing between the first inspection rod and the second inspection rod according to the shadow patterns; and determining the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the axis spacing between the first inspection rod and the second inspection rod.

[0006] Further, for the method for detecting the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the present invention, when rotating the azimuth axis, the shadow patterns obtained by the first inspection rod and the second inspection rod under the parallel light irradiation respectively include: projecting parallel light on one side of the first inspection rod, and obtaining a first shadow pattern on a first receiving plane on the other side of the first inspection rod; rotating the azimuth axis by 180°, projecting the parallel light from one side of the second inspection rod, and obtaining a second shadow pattern on a first receiving plane on the other side of the second inspection rod.

[0007] Further, for the method for detecting the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the present invention, determining the axial distance between the first inspection rod and the second inspection rod according to the shadow pattern includes: taking the projection line of the axis of the first inspection rod on the first receiving plane as the first axis, taking the projection line of the axis of the second inspection rod on the first receiving plane as the second axis, and determining the positions of the first axis and the second axis on the first receiving plane according to the shadow pattern; determining the linear distance between the first axis and the second axis according to the positions of the first axis and the second axis on the first receiving plane; and determining the axial distance between the first inspection rod and the second inspection rod according to the linear distance between the first axis and the second axis.

[0008] Further, for the method for detecting the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the present invention, determining the positions of the first axis and the second axis on the first receiving plane according to the shadow pattern includes: establishing a coordinate system on the first receiving plane; the shadow patterns of the first inspection rod and the second inspection rod on the first receiving plane are the first shadow pattern and the second shadow pattern respectively, the first shadow pattern includes a first side line and a second side line, and determining the first axis equation of the first axis in the coordinate system according to the first side line and the second side line; the second shadow pattern includes a third side line and a fourth side line, and determining the second axis equation of the second axis in the coordinate system according to the third side line and the fourth side line.

[0009] Further, for the method for detecting the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the present invention, it is characterized in that determining the first axis equation of the first axis in the coordinate system according to the first side line and the second side line includes: the first inspection rod is a cylinder, and the first side line is parallel to the second side line; establishing a rectangular coordinate system on the first receiving plane; respectively determining the equations of the first side line and the second side line in the rectangular coordinate system, which are: y = ax + b1, y = ax + b2; and determining the first axis equation as: y = ax + (b1 + b2) / 2 according to the equation of the first side line and the equation of the second side line, where a is the slope of the first side line or the second side line, b1 and b2 are the intercepts of the first side line and the second side line on the vertical axis of the rectangular coordinate system respectively, and (x, y) is the coordinate of a point on the first side line or the second side line or the first axis in the rectangular coordinate.

[0010] Further, for the method for detecting the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the present invention, determining the axis distance between the first inspection rod and the second inspection rod based on the line distance between the first axis and the second axis includes: the second inspection rod is a cylinder, and the third side line is parallel to the fourth side line; respectively determining the equations of the third side line and the fourth side line in the rectangular coordinate system, which are: y = ax + b3, y = ax + b4; determining the equation of the second axis according to the equations of the third side line and the fourth side line as: y = ax + (b3 + b4) / 2; determining the line distance between the first axis and the second axis according to the equation of the first axis and the equation of the second axis as:

[0011]

[0012] The axis distance between the first inspection rod and the second inspection rod is:

[0013]

[0014] where a is the slope of the third side line or the fourth side line, b3 and b4 are the intercepts of the third side line and the fourth side line on the vertical axis of the rectangular coordinate system respectively, and (x, y) is the coordinate of a point on the third side line or the fourth side line or the second axis in the rectangular coordinate system.

[0015] Further, for the method for detecting the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the present invention, it includes: respectively arranging adapter pieces at both ends of the pitch axis; respectively arranging the first inspection rod and the second inspection rod outside the adapter pieces; adjusting the adapter pieces to adjust the spatial positions of the first inspection rod and the second inspection rod so that the axes of the first inspection rod and the second inspection rod coincide with the central axis of the pitch axis.

[0016] Another aspect of the present invention provides a system for detecting the intersection error between the pitch axis and the azimuth axis of a laser tracker, including: a first inspection rod and a second inspection rod, which are respectively arranged at both ends of the pitch axis and are used to determine the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the axis distance between the first inspection rod and the second inspection rod. Among them, the first inspection rod and the second inspection rod are rotating bodies with a generatrix and an axis, the generatrix is a straight line, and the axis coincides with the central axis of the pitch axis; a light source, which is used to emit parallel light so that the first inspection rod and the second inspection rod obtain shadow patterns under the irradiation of the parallel light. Among them, the irradiation direction of the parallel light is parallel to the axis of the azimuth axis; a receiver, including a first receiving plane, and the first receiving plane is used to receive and present the shadow pattern.

[0017] Further, for the system for detecting the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the present invention, it includes: an adapter piece, which is arranged between the first inspection rod and the pitch axis or between the second inspection rod and the pitch axis and is used to adjust the spatial positions of the first inspection rod and the second inspection rod so that the axes of the first inspection rod and the second inspection rod coincide with the central axis of the pitch axis.

[0018] Further, the intersection error detection system for the pitch axis and azimuth axis of the laser tracker of the present invention is characterized in that it includes: a support frame for connecting and fixing a light source and a receiver, so that the light source and the receiver are fixed relative to the laser tracker.

[0019] The present invention has the following beneficial effects:

[0020] (1) The intersection of the pitch axis and azimuth axis of the laser tracker can be detected by measuring and calculating with a coaxial inspection rod and a projected image. This method has a simple measurement process and high measurement accuracy, and can meet the requirements for high-precision detection of the intersection error of the laser tracker's axis system;

[0021] (2) The intersection error detection method for the pitch axis and azimuth axis proposed in the present invention is applicable to the accuracy of intersection error detection of the axis systems of most two-dimensional turntables, and can meet the requirements for intersection error detection of two-dimensional turntables in precision assembly and detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of the laser tracker;

[0023] Figure 2 is a flow chart of the intersection error detection method for the pitch axis and azimuth axis of the laser tracker of the present invention;

[0024] Figure 3 is a flow chart of determining the positions of the first axis and the second axis on the first receiving plane according to the shadow pattern of the present invention;

[0025] Figure 4 is a schematic diagram of the use of the intersection error detection system for the pitch axis and azimuth axis of the laser tracker in some embodiments of the present invention;

[0026] Figure 5 is a schematic diagram of the use of the intersection error detection system for the pitch axis and azimuth axis of the laser tracker in other embodiments of the present invention.

[0027] In the figure:

[0028] 1. Pitch axis; 2. Azimuth axis; 3. Reflector; 4. First inspection rod; 5. Second inspection rod; 6. Light source; 7. Receiver; 8. First receiving plane; 9. Adapter; 10. Support frame. DETAILED DESCRIPTION OF THE INVENTION

[0029] Such as Figure 1 is a schematic structural diagram of the laser tracker. From Figure 1It can be known that the laser tracker includes: a pitch axis 1, a azimuth axis 2, and a reflector 3. The azimuth axis 2 can carry the reflector 3 and rotate on the horizontal plane, and the pitch axis 1 can make the reflector 3 rotate on the vertical plane. The combined action of the two enables the laser tracker to perform three-dimensional rotation within the measurement space. The azimuth axis 2 and the pitch axis 1 should intersect under ideal conditions. However, due to machining and assembly errors in the mechanical structure, the pitch axis 1 and the azimuth axis 2 do not intersect, that is, there is a certain distance between the pitch axis 1 and the azimuth axis 2 in space.

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the following further elaborates on the present invention in detail with reference to specific embodiments and the accompanying drawings.

[0031] See Figure 2 , the method for detecting the intersection error between the pitch axis and the azimuth axis of the laser tracker proposed by the present invention includes the following steps:

[0032] S201, respectively set a first inspection rod and a second inspection rod at both ends of the pitch axis. Among them, the first inspection rod and the second inspection rod are rotating bodies with a generatrix and an axis, the generatrix is a straight line, and the axis coincides with the central axis of the pitch axis.

[0033] Both the pitch axis and the azimuth axis of the laser tracker are in the shape of a cylinder. When rotating the azimuth axis or the pitch axis, they both rotate around the central axis of their cylindrical shape. When the pitch axis and the azimuth axis do not intersect, their central axes do not coincide. When the azimuth axis rotates 180° around its central axis, the central axis of the pitch axis will have a displacement on the horizontal plane, and this displacement is twice the intersection error between the pitch axis and the azimuth axis.

[0034] To determine the position of the central axis of the pitch axis, the present invention respectively sets a first inspection rod and a second inspection rod at both ends of the pitch axis, and the first inspection rod and the second inspection rod are rotating bodies with a generatrix and an axis. When the axis of the rotating body coincides with the central axis of the pitch axis, as long as the position of the axis of the rotating body is determined, the position of the central axis of the pitch axis can be determined.

[0035] According to some embodiments of the present invention, the rotating bodies used for the first inspection rod and the second inspection rod of the present invention can be in the shape of a cylinder or a cone, and thus the position of the central axis of the pitch axis can be determined by using the position of the axis of the rotating body.

[0036] According to some embodiments of the present invention, the first inspection rod and the second inspection rod of the present invention can use rotating bodies with different shapes or sizes, as long as the axis positions of the first inspection rod and the second inspection rod can be calculated.

[0037] According to some embodiments of the present invention, the following method is adopted to set the first inspection rod and the second inspection rod: adapter parts are respectively arranged at both ends of the pitching axis; the first inspection rod and the second inspection rod are respectively arranged outside the adapter parts; the adapter parts are adjusted to adjust the spatial positions of the first inspection rod and the second inspection rod, so that the axes of the first inspection rod and the second inspection rod coincide with the central axis of the pitching axis.

[0038] The first inspection rod and the second inspection rod are connected to the pitching axis by using adapter parts, and the spatial positions of the first inspection rod and the second inspection rod can be adjusted by adjusting the adapter parts. Ensure that the axes of the first inspection rod and the second inspection rod coincide with the central axis of the pitching axis, so that the spatial positions of the axes of the first inspection rod and the second inspection rod can be directly used to reflect the position of the central axis of the pitching axis.

[0039] S202, rotate the azimuth axis, and respectively obtain the shadow patterns of the first inspection rod and the second inspection rod obtained under the illumination of parallel light. Among them, the illumination direction of the parallel light is parallel to the axis of the azimuth axis, and the shadow patterns are presented on the first receiving plane.

[0040] According to some embodiments of the present invention, the following operations are adopted to respectively obtain the shadow patterns of the first inspection rod and the second inspection rod obtained under the illumination of parallel light: project parallel light on one side of the first inspection rod, and obtain the first shadow pattern on the first receiving plane on the other side of the first inspection rod; rotate the azimuth axis by 180°, project the parallel light from one side of the second inspection rod, and obtain the second shadow pattern on the first receiving plane on the other side of the second inspection rod.

[0041] According to some embodiments of the present invention, parallel light can be arranged beside the laser tracker, and the illumination direction of the parallel light is parallel to the axis of the azimuth axis. According to the illumination direction at this time, the parallel light will irradiate in a direction perpendicular to the central axis of the pitching axis. Adjusting the illumination position of the parallel light can make the parallel light irradiate on the first inspection rod from one side, and leave the shadow pattern of the first inspection rod on the other side. Use the first receiving plane to receive and present the shadow pattern of the first inspection rod, that is, the first shadow pattern is obtained.

[0042] Rotate the azimuth axis by 180°. At this time, the second inspection rod rotates to the position of the first inspection rod. At this position, the parallel light irradiates from one side of the second inspection rod, and leaves the shadow pattern of the second inspection rod on the other side. Use the first receiving plane to receive and present the shadow pattern of the second inspection rod, that is, the second shadow pattern is obtained.

[0043] According to some embodiments of the present invention, the positions of the parallel light and the first receiving plane relative to the laser tracker can be set to be relatively fixed. When the azimuth axis rotates before and after, the first shadow pattern and the second shadow pattern will be respectively received and presented on the first receiving plane. By comparing the positions of the first shadow pattern and the second shadow pattern on the first receiving plane, the relative displacement of the first shadow pattern and the second shadow pattern can be determined.

[0044] S203. Determine the axial distance between the first inspection rod and the second inspection rod according to the shadow pattern.

[0045] According to some embodiments of the present invention, determining the axial distance between the first inspection rod and the second inspection rod according to the shadow pattern includes: taking the projection line of the axis of the first inspection rod on the first receiving plane as the first axis, taking the projection line of the axis of the second inspection rod on the first receiving plane as the second axis, determining the positions of the first axis and the second axis on the first receiving plane according to the shadow pattern; determining the linear distance between the first axis and the second axis according to the positions of the first axis and the second axis on the first receiving plane; and determining the axial distance between the first inspection rod and the second inspection rod according to the linear distance between the first axis and the second axis.

[0046] According to some embodiments of the present invention, when the first inspection rod or the second inspection rod uses a cylindrical shape, the projection of the cylinder on the plane is a rectangle, and the projection of the axis of the cylinder on the plane is the median bisector of the rectangle. The distance between the median bisector and two opposite sides of the projection matrix is equal. Therefore, the position of the median bisector of the projection rectangle can be determined according to the positions of two opposite sides of the projection rectangle.

[0047] After determining the positions of the median bisectors of the projection rectangles of the first inspection rod and the second inspection rod at the same time, the distance between them can be determined, and this distance can reflect the axial distance between the first inspection rod and the second inspection rod.

[0048] Furthermore, the present invention adopts a method of establishing a coordinate system on the first receiving plane to obtain the axial distance between the first inspection rod and the second inspection rod.

[0049] Such as Figure 3 , according to some embodiments of the present invention, determining the positions of the first axis and the second axis on the first receiving plane according to the shadow pattern includes:

[0050] S301. Establish a coordinate system on the first receiving plane.

[0051] According to some embodiments of the present invention, the established coordinate system is a rectangular coordinate system, and the following position determination and distance calculation can be performed in the rectangular coordinate system. However, in some other embodiments of the present invention, other coordinate systems such as polar coordinate systems can also be established. As long as the position of the shadow pattern on the first receiving plane can be reflected, and the axial distance between the first inspection rod and the second inspection rod can be calculated according to the position.

[0052] S302. The shadow patterns of the first inspection rod and the second inspection rod on the first receiving plane are the first shadow pattern and the second shadow pattern respectively. The first shadow pattern includes a first side line and a second side line. Determine the first axis equation of the first axis in the coordinate system according to the first side line and the second side line;

[0053] S303. The second shadow pattern includes a third side line and a fourth side line, and a second axis equation of the second axis in the coordinate system is determined according to the third side line and the fourth side line.

[0054] In some embodiments of the present invention, the above steps S302 - S303 may be, for example, position determination and spacing calculation performed in a rectangular coordinate system. The first side line and the second side line of the first shadow pattern, and the third side line and the fourth side line of the second shadow pattern are all related to the selected generatrix of the rotating body. The generatrix of the rotating body selected in the embodiments of the present invention is a straight line. Therefore, the first side line and the second side line, and the third side line and the fourth side line are all straight lines. Therefore, the first axis equation of the first axis in the coordinate system can be obtained through the first side line and the second side line, and the second axis equation of the second axis in the coordinate system can be obtained through the third side line and the fourth side line.

[0055] When the first inspection rod or the second inspection rod selects a rotating body with a different shape, the first shadow pattern and the second shadow pattern on the first receiving plane may have different shapes. For example, when the first inspection rod selects a cylindrical shape, the first shadow pattern is a rectangle, and when the first inspection rod selects a conical shape, the first shadow pattern is an isosceles triangle. On the first receiving plane, the position of the median bisector can be determined through the position of the rectangle, and the position of the height line can be determined through the position of the isosceles triangle. And the position of the median bisector or the position of the height line is the position of the first axis, and then the first axis equation of the first axis on the first receiving plane can be obtained.

[0056] According to some embodiments of the present invention, both the first inspection rod and the second inspection rod adopt a cylindrical shape. Then the first side line is parallel to the second side line, and the third side line is parallel to the fourth side line.

[0057] A rectangular coordinate system is established on the first receiving plane; the equations of the first side line and the second side line in the rectangular coordinate system are determined respectively. The equations of the first side line and the second side line are: y = ax + b1, y = ax + b2 (since the two lines are parallel, the slopes are equal, both are a). Then the first axis equation is determined as: y = ax + (b1 + b2) / 2. The equations of the third side line and the fourth side line in the rectangular coordinate system are determined respectively as: y = ax + b3, y = ax + b4 (since the two lines are parallel, and because the third side line and the fourth side line are both parallel to the first side line and the second side line, the slopes are both a). Then the second axis equation is determined as: y = ax + (b3 + b4) / 2. b1 and b2 are the intercepts of the first side line and the second side line on the vertical axis of the rectangular coordinate system respectively, b3 and b4 are the intercepts of the third side line and the fourth side line on the vertical axis of the rectangular coordinate system respectively, and (x, y) is the coordinate of a point on the first side line or the second side line or the first axis or the third side line or the fourth side line or the second axis in the rectangular coordinate system.

[0058] For example, a rectangular coordinate system can be established with a straight line parallel to the first side line as the x-axis. It should be noted that the x-axis and y-axis of the rectangular coordinate system can be parallel or intersect with a certain side line, and the specific direction can be determined according to the actual application scenario, which is not limited in the present disclosure.

[0059] S204. Determine the intersection error of the pitch axis and azimuth axis of the laser tracker according to the axial distance between the first inspection rod and the second inspection rod.

[0060] In the above steps, the first axis equation has been obtained as: y = ax + (b1 + b2) / 2, and the second axis equation is: y = ax + (b3 + b4) / 2. Then the linear distance between the first axis and the second axis is: Then the axial distance between the first inspection rod and the second inspection rod is: Then the intersection error of the pitch axis and azimuth axis of the laser tracker is

[0061] On the other hand, the present invention proposes a system for detecting the intersection error of the pitch axis and azimuth axis of a laser tracker.

[0062] Such as Figure 4 is a schematic diagram of the use of the system for detecting the intersection error of the pitch axis and azimuth axis of the laser tracker according to some embodiments of the present invention. It can be seen from Figure 4 that the system includes:

[0063] A first inspection rod 4 and a second inspection rod 5, which are used to determine the intersection error of the pitch axis 1 and azimuth axis 2 of the laser tracker according to the axial distance between the first inspection rod 4 and the second inspection rod 5; a light source 6, which is used to emit parallel light so that the first inspection rod and the second inspection rod obtain shadow patterns under the illumination of the parallel light; a receiver 7, which includes a first receiving plane 8, and the first receiving plane 8 is used to receive and present the shadow patterns.

[0064] According to some embodiments of the present invention, when using the system, the first inspection rod 4 and the second inspection rod 5 are arranged at both ends of the pitch axis 1, and the axes of the first inspection rod 4 and the second inspection rod 5 in the shape of a rotating body coincide with the central axis of the pitch axis 1.

[0065] According to some other embodiments of the present invention, the system of the present invention further includes an adapter 9, which is used to adjust the spatial positions of the first inspection rod 4 and the second inspection rod 5 so that the axes of the first inspection rod 4 and the second inspection rod 5 coincide with the central axis of the pitch axis 1.

[0066] According to some other embodiments of the present invention, when using the system, an adapter 9 is connected between the first inspection rod 4 and the pitch axis 1 and between the second inspection rod 5 and the pitch axis 1. By adjusting the adapter 9, the axes of the first inspection rod 4 and the second inspection rod 5 can coincide with the central axis of the pitch axis 1.

[0067] According to some other embodiments of the present invention, the system of the present invention further includes a support frame 10, and the support frame 10 is used to connect and fix the light source 6 and the receiver 7, so that the light source 6 and the receiver 7 are fixed relative to the laser tracker in position.

[0068] According to some other embodiments of the present invention, the support frame 10 can be arranged and fixed on one side of the laser tracker, so that the light source 6 and the receiver 7 connected to the support frame 10 are fixed relative to the laser tracker in position, and the parallel light emitted by the light source 6 can pass through the first test bar 4 or the second test bar 5 to leave a shadow pattern on the first receiving plane 8.

[0069] As Figure 5 It is a schematic diagram of the use of the intersection error detection system for the pitch axis and the azimuth axis of the laser tracker according to some other embodiments of the present invention. In these embodiments, the adapter 9 and the support frame 10 are used simultaneously.

[0070] The specific embodiments described above have further elaborated on the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for detecting the intersection error of the pitch axis and the azimuth axis of a laser tracker, characterized in that Comprising: A first inspection rod and a second inspection rod are respectively arranged at both ends of the pitching axis. Among them, the first inspection rod and the second inspection rod are rotating bodies with a generatrix and an axis, the generatrix is a straight line, and the axis coincides with the central axis of the pitching axis; Rotate the azimuth axis, and respectively obtain the shadow patterns of the first inspection rod and the second inspection rod under the illumination of parallel light. Among them, the illumination direction of the parallel light is parallel to the axis of the azimuth axis, and the shadow pattern is presented on the first receiving plane; Determine the axis spacing between the first inspection rod and the second inspection rod according to the shadow pattern. Establish a rectangular coordinate system on the first receiving plane. Take the projection line of the axis of the first inspection rod on the first receiving plane as the first axis, and take the projection line of the axis of the second inspection rod on the first receiving plane as the second axis. The shadow patterns of the first inspection rod and the second inspection rod on the first receiving plane are respectively the first shadow pattern and the second shadow pattern. The first shadow pattern includes a first side line and a second side line. The first inspection rod is a cylinder, and the first side line is parallel to the second side line. According to the first side line and the second side line, determine that the first axis equation of the first axis in the rectangular coordinate system is: y = ax + (b1 + b2) / 2. The second shadow pattern includes a third side line and a fourth side line. The second inspection rod is a cylinder, and the third side line is parallel to the fourth side line. According to the third side line and the fourth side line, determine that the second axis equation is: y = ax + (b3 + b4) / 2. The axis spacing between the first inspection rod and the second inspection rod is: Wherein, a is the slope of the first side line, the second side line, the third side line or the fourth side line, b1, b2, b3 and b4 are respectively the intercepts of the first side line to the fourth side line on the vertical axis of the rectangular coordinate system, and (x, y) is the coordinate in the rectangular coordinate system; Determine the intersection error of the pitching axis and the azimuth axis of the laser tracker according to the axis spacing between the first inspection rod and the second inspection rod.

2. The method for detecting the intersection error of the pitch axis and the azimuth axis of the laser tracker according to claim 1, wherein The rotating the azimuth axis and respectively obtaining the shadow patterns of the first inspection rod and the second inspection rod under the illumination of parallel light includes: Project parallel light on one side of the first inspection rod, and obtain a first shadow pattern on the first receiving plane on the other side of the first inspection rod; Rotate the azimuth axis by 180°, project the parallel light from one side of the second inspection rod, and obtain a second shadow pattern on the first receiving plane on the other side of the second inspection rod.

3. The method for detecting the intersection error of the pitch axis and the azimuth axis of the laser tracker according to claim 1, characterized in that, The determining the axis spacing between the first inspection rod and the second inspection rod according to the shadow pattern includes: Determine the positions of the first axis and the second axis on the first receiving plane according to the shadow pattern; Determine the line spacing between the first axis and the second axis according to the positions of the first axis and the second axis on the first receiving plane; Determine the axis spacing between the first inspection rod and the second inspection rod according to the line spacing between the first axis and the second axis.

4. The method for detecting the intersection error of the pitch axis and the azimuth axis of the laser tracker according to claim 1, wherein The determining the first axis equation of the first axis in the rectangular coordinate system according to the first side line and the second side line includes: Determine the equations of the first side line and the second side line in the rectangular coordinate system respectively, where the equations of the first side line and the second side line are: y = ax + b1, y = ax + b2; Determine the first axis equation according to the equations of the first side line and the second side line.

5. The method for detecting the intersection error of the pitch axis and the azimuth axis of the laser tracker according to claim 4, wherein, The determining the axis distance between the first inspection rod and the second inspection rod according to the line distance between the first axis and the second axis includes: Determine the equations of the third side line and the fourth side line in the rectangular coordinate system respectively, where the equations of the third side line and the fourth side line are: y = ax + b3, y = ax + b4; Determine that the line spacing between the first axis and the second axis according to the first axis equation and the second axis equation is as follows: .

6. The method for detecting the intersection error of the pitch axis and the azimuth axis of a laser tracker according to any one of claims 1-5, characterized in that, Include: Set adapters at both ends of the pitch axis respectively; Set the first inspection rod and the second inspection rod outside the adapters respectively; Adjust the adapters to adjust the spatial positions of the first inspection rod and the second inspection rod so that the axes of the first inspection rod and the second inspection rod coincide with the central axis of the pitch axis.

7. A detection system for the intersection error of the pitch axis and the azimuth axis of a laser tracker, characterized in that, Include: The first inspection rod and the second inspection rod are respectively arranged at both ends of the pitch axis and are used to determine the intersection error between the pitch axis and the azimuth axis of the laser tracker according to the axis distance between the first inspection rod and the second inspection rod. The first inspection rod and the second inspection rod are rotating bodies with a generatrix and an axis. The generatrix is a straight line, and the axis coincides with the central axis of the pitch axis; A light source is used to emit parallel light so that the first inspection rod and the second inspection rod obtain shadow patterns under the irradiation of the parallel light, where the irradiation direction of the parallel light is parallel to the axis of the azimuth axis; The receiver includes a first receiving plane, and the first receiving plane is used to receive and present the shadow pattern; The intersection error detection system determines the axis distance between the first inspection rod and the second inspection rod according to the shadow pattern, establishes a rectangular coordinate system on the first receiving plane, takes the projection line of the axis of the first inspection rod on the first receiving plane as the first axis, and takes the projection line of the axis of the second inspection rod on the first receiving plane as the second axis. The shadow patterns of the first inspection rod and the second inspection rod on the first receiving plane are the first shadow pattern and the second shadow pattern respectively. The first shadow pattern includes a first side line and a second side line. The first inspection rod is a cylinder, and the first side line is parallel to the second side line. According to the first side line and the second side line, the first axis equation of the first axis in the rectangular coordinate system is: y = ax + (b1 + b2) / 2. The second shadow pattern includes a third side line and a fourth side line. The second inspection rod is a cylinder, and the third side line is parallel to the fourth side line. According to the third side line and the fourth side line, the second axis equation is: y = ax + (b3 + b4) / 2. The axis distance between the first inspection rod and the second inspection rod is: Wherein, a is the slope of the first side line, the second side line, the third side line or the fourth side line, b1, b2, b3 and b4 are the intercepts of the first side line to the fourth side line on the vertical axis of the rectangular coordinate system respectively, and (x, y) are the coordinates in the rectangular coordinate system; the intersection error of the pitch axis and the azimuth axis of the laser tracker is determined according to the axial distance between the first inspection rod and the second inspection rod.

8. The intersection error detection system for the pitch axis and the azimuth axis of the laser tracker according to claim 7, characterized in that, Comprising: An adapter, which is arranged between the first inspection rod and the pitch axis or between the second inspection rod and the pitch axis, and is used to adjust the spatial position of the first inspection rod or the second inspection rod so that the axes of the first inspection rod and the second inspection rod coincide with the central axis of the pitch axis.

9. The intersection error detection system for the pitch axis and the azimuth axis of the laser tracker according to claim 7, characterized in that, Comprising: A support frame, which is used to connect and fix the light source and the receiver so that the positions of the light source and the receiver are fixed relative to the laser tracker.

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