Method and device for detecting rotation axis error of rotary table of rotary axis laser tracker with integral measurement optical path connection

Abstract

The present application discloses a method and device for detecting the axis error of the turntable of a rotary-axis laser tracker with an overall measurement optical path connection, belonging to the field of laser tracking measurement technology, and comprising: a microscope, a fluorescent microsphere, a substrate, and a six-dimensional precision calibration displacement stage, wherein the microscope is located above the fluorescent microsphere, the fluorescent microsphere is fixed on the substrate, and the substrate is fixed on the six-dimensional precision calibration displacement stage. The present application realizes the determination of the spatial straight line equations of the axis of the upper and lower turntables of the rotary-axis laser tracker with an overall measurement optical path connection in one coordinate system and the detection of the shaft diameter jump within a complete rotation cycle by combining a fluorescent microscope with an astigmatic imaging function, a precision displacement stage, and spatial coordinate solution and other operations, thereby laying the necessary technical foundation for realizing the compensation of the axis error of the turntable of the rotary-axis laser tracker with an overall measurement optical path connection and improving the tracking accuracy and stability of the laser tracker.

Description

Technical Field

[0001] The present invention relates to the field of laser tracking measurement technology, and in particular to a method and device for detecting rotation axis errors of a rotary table of a rotary axis laser tracker connected to an integral measurement optical path. Background Art

[0002] Laser trackers, characterized by high speed, high accuracy, and a large measurement range, are widely used in aerospace, automotive, electronics, and large-scale metrology. Currently, many laser trackers on the market use an integrated measurement optical path as the middle section of the upper turntable's axis, connecting the motor-side and encoder-side axes to achieve servo pitch rotation of the upper turntable.

[0003] The laser tracker's turntable consists of an upper pitch rotation turntable and a lower horizontal rotation turntable, corresponding to the pitch and horizontal axes, respectively. Ideally, the two axes intersect perfectly perpendicularly in space (without distance deviation), and both axes rotate with no axial or radial runout. However, in reality, the two axes are not perfectly perpendicular at 90°, nor do they intersect perfectly in space (with distance deviation), and they also experience radial runout during rotation. These non-ideal errors can affect the tracking accuracy and stability of the laser tracker, necessitating detection and calibration of these axis-related errors to provide the prerequisites for error compensation.

[0004] Testing the perpendicularity and distance deviation of the two rotating axes of a laser tracker can be attributed to determining the spatial linear equations of the two rotating axes. Therefore, axis error detection includes determining the spatial linear equations of the rotating axes and detecting the axis runout. Currently, separate technologies and methods for detecting the perpendicularity and axis runout of the two rotating axes of a laser tracker are relatively common, but no articles or technical materials have proposed methods and techniques for determining the spatial linear equations of the axes and simultaneously detecting the axis runout in a single coordinate system. For a laser tracker turntable with an integral measurement optical path connected to an upper rotating axis, because its upper rotating axis is divided into a motor side and an encoder side, in addition to detecting the spatial linear equations and axis runout of the lower rotating axis, it is also necessary to detect the spatial linear equations and axis runout of both rotating axes of the upper rotating axis. Currently, no articles or documents have been found that describe methods and techniques for determining the spatial linear equations of the three axes and simultaneously detecting the axis runout of this type of laser tracker turntable with an integral measurement optical path connected to an upper rotating axis. Summary of the Invention

[0005] In response to the above problems, the present invention proposes a method and device for detecting the rotation axis error of a rotary table of a rotary axis laser tracker with an overall measurement optical path connection, so as to realize the determination of the spatial linear equations of the three-axis axis and the simultaneous detection of the axis diameter runout.

[0006] In a first aspect, the present application provides a method for detecting the rotation axis error of a rotary table of a rotary laser tracker with an integral measurement optical path connection, comprising the following steps:

[0007] Step S1: constructing a microscope using an objective lens, a cylindrical lens, a charge-coupled image sensor, a standard 45-degree beam splitting square mirror block, and a fluorescence excitation light source;

[0008] Step S2: setting a microscope, fluorescent microspheres, a substrate, and a six-dimensional precision calibration stage to image the fluorescent microspheres on the charge-coupled image sensor;

[0009] Step S3: causing the six-dimensional precision calibration stage to perform translational motion in two non-parallel directions to obtain three XY axis width ratios corresponding to three images of the fluorescent microsphere before and after the movement on the charge-coupled image sensor, and determining a posture vector of the six-dimensional precision calibration stage corresponding to the same three XY axis width ratios before and after the movement;

[0010] Step S4: causing the six-dimensional precision calibration stage to move back and forth along the direction of the posture vector while ensuring that the fluorescent microspheres can be imaged on the charge-coupled image sensor, thereby obtaining a functional relationship between the ratio of the fluorescent microspheres' heights to the XY-axis widths at different longitudinal object planes, i.e., a longitudinal object plane height function; translating the six-dimensional precision calibration stage by an actual displacement value on each longitudinal object plane to determine a corresponding measured displacement value of the fluorescent microspheres imaged on the charge-coupled image sensor, and obtaining a microscope magnification function based on the actual displacement value and the measured displacement value;

[0011] Step S5: fixing the first gear and the second gear to the first rotating shaft and the second rotating shaft of the upper turntable respectively, and fixing a bracket with a gear transmission shaft on one side to the table surface of the lower turntable;

[0012] Step S6: fixing the microscope on a six-dimensional precision adjustment stage, fixing the substrate with fluorescent microspheres on the table of a micro-translation adjustment stage, and fixing the micro-translation adjustment stage on the upper turntable, the first rotation axis, the second rotation axis, and the lower turntable rotation axis in sequence;

[0013] Step S7: fixing the micro-translation adjustment stage with the fluorescent microspheres and the substrate on the lower turntable shaft, starting the lower turntable motor, rotating the lower turntable shaft through a minimum step angle and then stopping, recording the microscope imaging of the fluorescent microspheres, determining the centroid coordinates and the XY axis width ratio in the charge-coupled image sensor imaging plane coordinates using a two-dimensional Gaussian function, determining the microscopic magnification corresponding to the longitudinal object plane height of the fluorescent microspheres based on the XY axis width ratio, and determining the spatial coordinate value of the fluorescent microspheres mapped to the charge-coupled image sensor imaging plane coordinates based on the centroid coordinates and the microscopic magnification;

[0014] Step S8: constructing a first reference coordinate system based on the spatial coordinate values, determining the spatial linear equation of the rotation axis of the lower turntable in the first reference coordinate system, and obtaining the radial runout value of the lower turntable rotation axis within a complete rotation cycle;

[0015] Step S9: Setting the rotation axis of the lower turntable to be stationary, recording the spatial coordinate values of the fluorescent microspheres in the first reference coordinate system at this time, constructing a motion coordinate system of the six-dimensional precision adjustment translation stage, determining a first vector value of the unit vector on the X-axis of the motion coordinate system in the first reference coordinate system, determining a first coordinate value of the origin of the motion coordinate system in the first reference coordinate system, rotating the six-dimensional precision adjustment translation stage around the X-axis of the motion coordinate system by a first angle, and rotating the unit vector in the first reference coordinate system around the first vector value by the first angle to obtain a second vector value;

[0016] Step S10: Rotating the first reference coordinate system around the X-axis of the motion coordinate system by the first angle to obtain a measurement coordinate system of the microscope, determining the spatial coordinate values of the fluorescent microspheres in the measurement coordinate system, and obtaining the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment translation stage is rotated by the first angle;

[0017] Step S11: Rotate the six-dimensional precision adjustment stage back to the starting position, determine the third vector value of the unit vector on the Y-axis of the motion coordinate system of the six-dimensional precision adjustment stage in the first reference coordinate system, rotate the six-dimensional precision adjustment stage around the Y-axis of the motion coordinate system by a second angle, obtain the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment stage is rotated by the second angle, and obtain the first vector value, the first coordinate value, and the third vector value using the least squares method;

[0018] Step S12: Fixing the micro-translation adjustment stage with the fluorescent microspheres and the substrate to the first rotation axis of the upper turntable, starting the upper turntable motor to control the rotation of the first rotation axis, constructing a second reference coordinate system, determining the spatial linear equation of the rotation axis on the motor side of the upper turntable in the second reference coordinate system, and obtaining the axial and radial runout values within a complete rotation cycle;

[0019] Step S13: Determine the yaw and pitch angles of the second reference coordinate system relative to the first reference coordinate system using the six-dimensional precision adjustment translation stage, convert the unit vector in the first reference coordinate system into the yaw and pitch angles, obtain the spatial coordinates of the fluorescent microspheres in the second reference coordinate system in the first reference coordinate system, and convert the spatial linear equation of the rotation axis of the upper turntable into the spatial linear equation in the first coordinate system;

[0020] Step S14: Fix the micro translation adjustment table with fluorescent microspheres and substrate on the second rotating shaft of the upper turntable, start the lower turntable motor, rotate 180 degrees to symmetrically exchange the positions of the upper turntable encoder side and the upper turntable motor side, and obtain the axial and radial runout values within a complete rotation cycle, and determine the spatial linear equations of the lower turntable rotation axis and the upper turntable encoder side rotation axis in the first reference coordinate system, so as to realize the determination of the spatial linear equations of the lower turntable rotation axis, the upper turntable motor side rotation axis and the upper turntable encoder side rotation axis in the same reference coordinate system and the error detection within a complete rotation cycle.

[0021] Optionally, a microscope is constructed using an objective lens, a cylindrical lens, a charge-coupled image sensor, a standard 45-degree beam splitter square mirror block, and a fluorescence excitation light source, including:

[0022] A cylindrical lens is placed between an objective lens and a charge coupled image sensor, wherein the bottom surface of the cylindrical lens is parallel to the charge coupled image sensor, and the edge where the semicircular cross section of the cylindrical lens intersects with the bottom surface of the cylindrical lens is parallel to the X-axis of the imaging surface of the charge coupled image sensor, and the normal vector of the imaging surface of the charge coupled image sensor is parallel to the imaging optical axis of the objective lens; a standard 45-degree beam splitting square mirror block is placed under the objective lens, wherein the standard 45-degree beam splitting square mirror block includes a beam splitting surface, wherein the edge of the beam splitting surface is parallel to the X-axis of the imaging surface of the charge coupled image sensor, and the fluorescent light beam enters the objective lens after passing through the beam splitting surface and is received by the charge coupled image sensor after passing through the cylindrical lens; a fluorescent excitation light source is placed on the side of the mirror surface that forms an angle of 45 degrees with the beam splitting surface; the objective lens, the charge coupled image sensor, the cylindrical lens, the standard 45-degree beam splitting square mirror block and the fluorescent excitation light source constitute a microscope; the coordinate value of the intersection of the imaging optical axis of the objective lens and the imaging surface of the charge coupled image sensor in its imaging surface plane coordinate system is ( x o , y o ), and the imaging optical axis of the objective lens passes through the center point of the splitting surface of the standard 45-degree splitting square mirror block, and the distance between the focal longitudinal object plane of the microscope and the center point of the splitting surface is D.

[0023] Optionally, setting a microscope, fluorescent microspheres, a substrate, and a six-dimensional precision calibration stage to image the fluorescent microspheres on the charge-coupled image sensor includes:

[0024] A fluorescent microsphere is fixed on a substrate, and the substrate is then fixed parallel to a six-dimensional precision calibration translation stage; the six-dimensional precision calibration translation stage with the substrate is placed at the lower end of the beam incident surface at the bottom of a standard 45-degree beam splitting square mirror block under a microscope; after turning on the fluorescent excitation light source, the light source beam is reflected by the standard 45-degree beam splitting square mirror block and then irradiated onto the fluorescent microsphere, causing the fluorescent microsphere to emit fluorescence. After being transmitted through the standard 45-degree beam splitting square mirror block, the fluorescent microsphere is imaged on the charge-coupled image sensor.

[0025] Optionally, causing the six-dimensional precision calibration stage to perform translational motion in two non-parallel directions to obtain three XY axis width ratios corresponding to three images of the fluorescent microsphere before and after the movement on the charge-coupled image sensor, and determining a posture vector of the six-dimensional precision calibration stage corresponding to the same three XY axis width ratios before and after the movement, includes:

[0026] The six-dimensional precision calibration stage is caused to perform translational motion in two non-parallel motion directions to obtain three XY-axis width ratios corresponding to three images of the fluorescent microsphere before and after the motion on the charge-coupled image sensor. If the three XY-axis width ratios are the same, the plane determined by the two motion directions is a longitudinal object plane of the fluorescence microscope. The pitch state and yaw posture of the six-dimensional precision calibration stage are traversed with a minimum step size. The above-mentioned translational motion is performed in each posture state, and the corresponding three imaging XY-axis width ratios are obtained. Then, a posture vector of the six-dimensional precision calibration stage corresponding to the same three XY-axis width ratios before and after the motion is determined.

[0027] Optionally, the six-dimensional precision calibration stage is moved back and forth along the direction of the posture vector, ensuring that the fluorescent microspheres can be imaged on the charge-coupled image sensor, to obtain a functional relationship between the ratios of the fluorescent microspheres at different longitudinal object plane heights and the XY axis widths, i.e., a longitudinal object plane height function; the six-dimensional precision calibration stage is translated by an actual displacement value on each longitudinal object plane to determine a corresponding measured displacement value of the fluorescent microspheres imaged on the charge-coupled image sensor; and a microscopic magnification function is obtained based on the actual displacement value and the measured displacement value, including:

[0028] The six-dimensional precision calibration stage is moved back and forth along the direction of the posture vector, and the fluorescent microspheres are ensured to be imaged on the charge-coupled image sensor, so as to obtain a functional relationship between the ratios of the fluorescent microspheres at different longitudinal object plane heights and the XY axis widths, i.e., a longitudinal object plane height function. The six-dimensional precision calibration stage is translated by an actual displacement value on each longitudinal object plane, and a measured displacement value of the fluorescent microspheres is obtained on the charge-coupled image sensor. The measured displacement value of the fluorescent microspheres is divided by the actual displacement value to obtain a microscopic magnification on each longitudinal object plane. The microscopic magnification function is determined according to different longitudinal object plane heights corresponding to different microscopic magnifications.

[0029] Optionally, the first gear and the second gear are fixed to the first rotating shaft and the second rotating shaft of the upper turntable respectively, and a bracket with a gear transmission shaft on one side is fixed to the table surface of the lower turntable, including:

[0030] The first gear and the second gear are fixed on the first rotating shaft and the second rotating shaft of the upper turntable respectively, and a bracket with a gear transmission shaft on one side is fixed on the table surface of the lower turntable. When the lower turntable rotates, it drives the upper turntable and the bracket to rotate. The bracket is fixed to the gear transmission shaft through a bearing, and the two ends of the gear transmission shaft are respectively engaged with the first gear and the second gear of the upper turntable. When the first rotating shaft of the upper turntable rotates, the rotational force is transmitted to the gear transmission shaft through the first gear, so that the gear transmission shaft rotates, and then drives the second gear to rotate, thereby rotating the second rotating shaft.

[0031] Optionally, the microscope is fixed on a six-dimensional precision adjustment displacement stage, the substrate with fluorescent microspheres is fixed on the table of a micro translation adjustment stage, and the micro translation adjustment stage is fixed on the upper turntable, the first rotation axis, the second rotation axis, and the lower turntable rotation axis in sequence, including:

[0032] Fix the microscope on a six-dimensional precision adjustment displacement stage; fix the substrate with fluorescent microspheres on the table top of a micro-translation adjustment stage, and fine-tune the spatial position of the fluorescent microspheres through the micro-translation adjustment stage; fix the micro-translation adjustment stage on the first rotating shaft, the second rotating shaft and the rotating shaft of the lower turntable in sequence. Each time the micro-translation adjustment stage is fixed, the upper turntable or the lower turntable motor is started to rotate the corresponding rotating shaft one circle, ensuring that the fluorescent microspheres are imaged by the microscope during the rotation of the shaft one circle.

[0033] Optionally, a micro-translation adjustment stage with fluorescent microspheres and a substrate is fixed to a lower turntable shaft, a lower turntable motor is started, the lower turntable shaft is rotated to a minimum step angle and then remains stationary, an imaging of the fluorescent microspheres by a microscope is recorded, the centroid coordinates and the XY axis width ratio in the imaging plane coordinates of a charge-coupled image sensor are determined using a two-dimensional Gaussian function, a microscopic magnification corresponding to the longitudinal object plane height of the fluorescent microspheres is determined based on the XY axis width ratio, and a spatial coordinate value of the fluorescent microspheres mapped to the imaging plane coordinates of the charge-coupled image sensor is determined based on the centroid coordinates and the microscopic magnification, including:

[0034] A micro translation adjustment stage with a fluorescent microsphere substrate is fixed on the lower turntable shaft, and the lower turntable motor is started to rotate the lower turntable shaft to a minimum step angle and then stop, and the imaging of the fluorescent microsphere by the microscope is recorded. The center of mass coordinates and the XY axis width ratio in the imaging plane coordinates of the charge coupled image sensor are obtained by fitting the imaging light intensity through a two-dimensional Gaussian function. The value of the microscope magnification function corresponding to the longitudinal object plane height of the fluorescent microsphere at this time is determined by the XY axis width ratio, that is, the microscope magnification at this time. The center of mass coordinates are divided by the magnification to obtain the spatial coordinate value of the fluorescent microsphere mapped to the imaging plane coordinates of the charge coupled image sensor; By analogy, after the lower turntable rotates one circle, a corresponding series of fluorescent microsphere spatial coordinate values are obtained, and the plane ellipse function is fitted to the series of fluorescent microsphere spatial coordinate values to obtain a plane mapping space trajectory, and the length values of the major and minor axes of the fitted ellipse are recorded at this time. The pitch posture and yaw posture of the six-dimensional precision adjustment displacement stage are traversed with the minimum step size, and a length value of the major and minor axes of the fitted ellipse is obtained for each posture. When the major axis and minor axis of the fitted ellipse corresponding to a certain posture are the minimum values of all the pitch postures and yaw postures traversed, that is, when the rotation axis is perpendicular to the imaging plane, the length of the spatial plane trajectory of the mapped image is the shortest, and at this time the rotation axis of the lower turntable is parallel to the imaging optical axis of the fluorescence microscope.

[0035] Optionally, constructing a first reference coordinate system based on the spatial coordinate values, determining the spatial linear equation of the rotation axis of the lower turntable in the first reference coordinate system, and obtaining the radial runout value of the lower turntable rotation axis within a complete rotation cycle includes:

[0036] In the case where the rotation axis of the lower turntable is parallel to the imaging optical axis of the microscope, on the premise that the imaging light intensity of the fluorescent microspheres corresponding to all step rotations of the lower turntable and their charge-coupled image sensor imaging plane coordinates are obtained, the center of mass coordinates and the XY axis width ratio in the charge-coupled image sensor imaging plane coordinates are obtained by two-dimensional Gaussian fitting of the imaging light intensity, the corresponding longitudinal object plane height value and the microscope magnification are obtained by the XY axis width ratio, the center of mass coordinates are divided by the microscope magnification, and the spatial coordinate value of the fluorescent microsphere mapped to the charge-coupled image sensor imaging plane coordinate is obtained. Let the center coordinate obtained after the plane elliptical function fitting of the spatial coordinate value be ( x 拟 , y 拟 ), the origin of the coordinate system of the CCI imaging plane is translated to the coordinate of the intersection of the imaging optical axis and the CCI imaging plane ( x o , y o ), and then translate along the imaging optical axis to the longitudinal object plane of the focal point. The corresponding coordinate system at this time is recorded as the first reference coordinate system X 基Y 基 Z 基 , the first reference coordinate system is the measurement coordinate system of the microscope at this time; the spatial coordinate value of the fluorescent microspheres mapped to the imaging plane coordinate of the charge coupled image sensor is subtracted from the intersection coordinate ( x o , y o ), get the first reference coordinate system X 基 Y 基 Z 基 The XY coordinate value of the fluorescent microsphere in the middle, the obtained vertical object plane height value is the first reference coordinate system X 基 Y 基 Z 基 The Z-axis coordinate value in the reference coordinate system X 基 Y 基 Z 基 Pass ( x 拟 - x o , y 拟 - y o ,0) point and with (0,0,1) as the direction of the spatial straight line equation, that is, the rotation axis of the lower turntable; in the first reference coordinate system X 基 Y 基 Z 基 In the figure, all axial runout values within a complete rotation cycle of the lower turntable shaft are the difference between the Z-axis value of the fluorescent microsphere corresponding to each rotation step angle of the lower turntable shaft and the Z-axis value of the fluorescent microsphere when it is not rotated. The radial runout value within a complete rotation cycle of the lower turntable shaft is the difference between the distance from the XY-axis plane coordinate of the fluorescent microsphere corresponding to each rotation step angle of the lower turntable shaft to the origin and the distance from the coordinate point on the fitted plane elliptical function corresponding to the rotation step angle to the origin.

[0037] Optionally, setting the lower turntable axis to be stationary, recording the spatial coordinate values of the fluorescent microspheres in the first reference coordinate system at this time, constructing a motion coordinate system of the six-dimensional precision adjustment displacement stage, determining a first vector value of the unit vector on the X-axis of the motion coordinate system in the first reference coordinate system, determining a first coordinate value of the origin of the motion coordinate system in the first reference coordinate system, rotating the six-dimensional precision adjustment displacement stage around the X-axis of the motion coordinate system by a first angle, and rotating the unit vector in the first reference coordinate system around the first vector value by the first angle to obtain a second vector value, including:

[0038] Make sure the lower turntable axis is stationary and record the position of the fluorescent microspheres in the first reference coordinate system X. 基 Y 基 Z 基 The spatial coordinate values in ; Construct the motion coordinate system X of the six-dimensional precision adjustment displacement stage 28 调 Y 调 Z 调 , assuming that the motion coordinate system X of the six-dimensional precision adjustment translation stage 调 Y 调 Z 调 The unit vector on the X axis in the first reference coordinate system X 基 Y 基 Z 基 The first vector value in is ( u X , u Y ,u Z ), coordinate system X 调 Y 调 Z 调 The origin of the first reference coordinate system X 基 Y 基 Z 基 The first coordinate value in is ( o X , o Y ,o Z ), so that the six-dimensional precision adjustment translation stage moves around the motion coordinate system X 调 Y 调 Z 调 The X axis rotates a first angle, that is, in the motion coordinate system X 基 Y 基 Z 基 In around the first vector value ( u X , u Y ,u Z ) rotates the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in the equation are about the first vector value ( u X , u Y ,u Z ) rotate the first angle; and set the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in the first coordinate value ( o X , oY ,o Z ) are subtracted, and the first rotation transformation matrix is multiplied on the right to obtain the unit vectors (1,0,0), (0,1,0) and (0,0,1) around the first vector value ( u X , u Y ,u Z ) After rotating the first angle in the first reference coordinate system X 基 Y 基 Z 基 The corresponding second vector value in the first rotation transformation matrix is expressed as:

[0039]

[0040] in, u X 、 u Y 、 u Z are the X-axis, Y-axis, and Z-axis values of the first vector value, θ is the first angle;

[0041] The first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in are respectively related to the first coordinate value ( o X , o Y ,o Z ) and subtract it to get (1- o X , - o Y , - o Z )、(- o X , 1- o Y , - o Z )and(- o X , - o Y , 1- o Z ), and then right-multiply the first rotation transformation matrix to obtain the second vector value, and then respectively add the second vector value to the first coordinate value (o X , o Y ,o Z ) are added together to obtain ( i x , i y , i z )、( j x , j y , j z )and( k x , k y , k z ); Compare the origin coordinate (0, 0, 0) with the first coordinate value ( o X , o Y ,o Z ) and then right-multiply it by the first rotation transformation matrix, and then add it to the first coordinate value ( o X , o Y ,o Z ) add up to get ( t x , t y , t z ), then in the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) are centered around the first vector value ( u X , u Y ,u Z ) After rotating the first angle, in the first reference coordinate system X 基 Y 基 Z 基 The majority of the second vector values in are ( i x - t x , i y - t y , iz - t z )、( j x - t x , j y - t y , j z - t z )and( k x - t x , k y - t y , k z - t z ).

[0042] Optionally, rotating the first reference coordinate system by the first angle around the X-axis of the motion coordinate system to obtain a measurement coordinate system of the microscope, determining the spatial coordinate values of the fluorescent microspheres in the measurement coordinate system, and obtaining the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment translation stage is rotated by the first angle include:

[0043] The six-dimensional precision adjustment stage moves around the coordinate system X 调 Y 调 Z 调 The X-axis rotates a first angle, driving the fluorescence microscope around the motion coordinate system X 调 Y 调 Z 调 The X-axis rotates by the first angle θ , at this time, the first reference coordinate system X 基 Y 基 Z 基 Also around the motion coordinate system X 调 Y 调 Z 调 The X-axis is rotated by a first angle to obtain the measurement coordinate system X of the microscope θ Y θ Z θ ; With the first reference coordinate system X in step S8 基 Y 基 Z 基 The measurement coordinate system of the microscope is similar to the situation, and the measurement coordinate system X of the fluorescent microsphere in the microscope is obtained. θ Y θ Z θ The spatial coordinate values in ( x θ ,y θ , z θ ), the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment stage is obtained, and the expression is as follows:

[0044]

[0045] in,( x θ , y θ , z θ ) is the measurement coordinate system X of the fluorescent microsphere in the microscope θ Y θ Z θ The spatial coordinate value in ; ( i x - t x , i y - t y , i z - t z )、( j x - t x , j y - t y , j z - t z )and( k x - t x , k y - t y , k z - t z ) are the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) are rotated around the first vector value ( u X , u Y ,u Z ) After rotating the first angle in the first reference coordinate system X 基 Y 基Z 基 The second vector value in ; The X coordinate of the fluorescent microsphere in the first reference coordinate system is when the lower turntable axis is stationary. 基 Y 基 Z 基 The spatial coordinate values in .

[0046] Optionally, the six-dimensional precision adjustment stage is rotated back to the starting posture, a third vector value of the unit vector on the Y-axis of the motion coordinate system of the six-dimensional precision adjustment stage in the first reference coordinate system is determined, the six-dimensional precision adjustment stage is rotated around the Y-axis of the motion coordinate system by a second angle, and the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment stage is rotated by the second angle is obtained. The first vector value, the first coordinate value, and the third vector value are obtained by the least squares method, including:

[0047] The six-dimensional precision adjustment platform is rotated back to the starting posture of step S9. Assume that the motion coordinate system X of the six-dimensional precision adjustment platform is 调 Y 调 Z 调 The unit vector on the Y axis of the first reference coordinate system X 基 Y 基 Z 基 The third vector value in is ( v X , v Y ,v Z ), so that the six-dimensional precision adjustment translation stage moves around the motion coordinate system X 调 Y 调 Z 调 The Y axis of the six-dimensional precision adjustment platform is rotated by a second angle; similarly, a spatial coordinate relationship of the fluorescent microsphere before and after the rotation of the six-dimensional precision adjustment platform is obtained, which is similar to expression (II); six relationships about nine unknown quantities are obtained, namely, the first vector value ( u X , u Y ,u Z ), the first coordinate value ( o X , o Y ,o Z ) and the third vector value ( v X , v Y ,v ZRepeat steps S9 to S11, rotate more different first angles and second angles to obtain more relations than the number of nine unknowns, thereby building an overdetermined system of equations, and calculating the first vector value ( u X , u Y ,u Z ), the first coordinate value ( o X , o Y ,o Z ) and the third vector value ( v X , v Y , v Z ).

[0048] Optionally, a micro-translation adjustment stage with fluorescent microspheres and a substrate is fixed to the first rotating shaft of the upper turntable, the motor of the upper turntable is started to control the rotation of the first rotating shaft, a second reference coordinate system is constructed, and the spatial linear equation of the rotation axis on the motor side of the upper turntable is determined in the second reference coordinate system to obtain the axial and radial runout values within a complete rotation cycle, including:

[0049] Fix the micro-translation adjustment stage with the fluorescent microsphere substrate on the first rotating shaft of the upper turntable, start the upper turntable motor to control the rotation of the first rotating shaft, and the rest of the operations are the same as steps S7 and S8. At this time, the measurement coordinate system of the microscope is X' 基 Y' 基 Z' 基 , that is, the second reference coordinate system is X' 基 Y' 基 Z' 基 Because the imaging fluorescence of the fluorescent microspheres is transmitted to the side beam incident surface of the standard 45-degree beam splitting square mirror block, the image is formed. Due to the mirror effect of the beam splitting surface of the standard 45-degree beam splitting square mirror block, the symmetrical mirror image of the fluorescent microspheres is obtained in the second reference coordinate system X' 基 Y' 基 Z' 基 The spatial coordinate values in are uniformly expressed as ( x’ , y',z' According to the distance D between the longitudinal object plane of the microscope and the center point of the spectroscopic plane in step S1, the actual fluorescent microspheres are obtained in the second reference coordinate system X' 基 Y' 基 Z' 基 The spatial coordinate values in are ( x’ ,y’ -D ,z’ +D), similar to step S8, in the second reference coordinate system X' 基 Y' 基 Z' 基 In the process, the spatial linear equation of the rotation axis of the upper turntable motor side and the axial and radial runout values within a complete rotation cycle are obtained.

[0050] Optionally, determining the yaw angle and pitch angle of the second reference coordinate system relative to the first reference coordinate system based on the six-dimensional precision adjustment translation stage, converting the unit vector in the first reference coordinate system into the yaw angle and pitch angle, obtaining the spatial coordinate values of the fluorescent microspheres in the second reference coordinate system in the first reference coordinate system, and converting the spatial straight line equation of the rotation axis of the upper turntable into the spatial straight line equation in the first coordinate system, including:

[0051] Since the second reference coordinate system X' 基 Y' 基 Z' 基 It is determined by the principle that the length of the spatial plane trajectory of the image mapped when the rotation axis is perpendicular to the imaging plane is the shortest, so the second reference coordinate system X' 基 Y' 基 Z' 基 With the first reference coordinate system X 基 Y 基 Z 基 There will be posture differences, which are due to the fact that the first reference coordinate system X 基 Y 基 Z 基 The corresponding six-dimensional precision adjustment translation stage posture is based on the second reference coordinate system X' 基 Y' 基 Z' 基 The corresponding six-dimensional precision adjustment platform has a yaw angle and a pitch angle, which are determined by the six-dimensional precision adjustment platform. The first reference coordinate system X 基 Y 基 Z 基 deflection θ' and pitch δ' After the angle is changed to the second reference coordinate system X' 基 Y' 基 Z' 基 , the corresponding second rotation transformation matrix that needs to be right multiplied is:

[0052]

[0053] in, θ' is the deflection angle, δ' is the pitch angle, ( u X , uY ,u Z ) is the motion coordinate system X of the six-dimensional precision adjustment translation stage 调 Y 调 Z 调 The unit vector on the X axis of the first reference coordinate system X 基 Y 基 Z 基 The first vector value in , ( v X , v Y ,v Z ) is the motion coordinate system X of the six-dimensional precision adjustment translation stage 调 Y 调 Z 调 The unit vector on the Y axis of the first reference coordinate system X 基 Y 基 Z 基 The third vector value in ;

[0054] By the second rotation transformation matrix and the motion coordinate system X 调 Y 调 Z 调 The origin of the first reference coordinate system X 基 Y 基 Z 基 The first coordinate value in ( o X , o Y ,o Z ), similar to the operation in step S9, the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0), (0,0,1) and the origin (0,0,0) are converted to ( i' x , i' y , i' z )、( j' x , j' y , j' z )、( k' x , k' y , k' z )and( t' x , t'y , t' z ), thereby obtaining the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in θ' and pitch δ' After the angle, in the first reference coordinate system X 基 Y 基 Z 基 becomes ( i' x - t' x , i' y - t' y , i' z - t' z )、( j' x - t' x , j' y - t' y , j' z - t' z )and( k' x - t' x , k' y - t' y , k' z - t' z ), and the fluorescent microspheres are obtained in the second reference coordinate system X' 基 Y' 基 Z' 基 The spatial coordinates in x’ , y’ -D ,z’ +D) corresponds to the first reference coordinate system X 基 Y 基 Z 基 The spatial coordinate values in ( x’ 基 , y’ 基 , z’ 基 ), the expression is:

[0055] ;

[0056] Wherein, D represents the distance between the longitudinal object plane of the microscope and the center point of the splitting plane; the second reference coordinate system X' 基 Y' 基 Z' 基 The coordinates of any two points on the space straight line equation of the rotation axis of the upper turntable motor side are converted by expression (Ⅳ) to obtain their coordinates in the first reference coordinate system X 基 Y 基 Z 基 The coordinate values in the first reference coordinate system X are thus determined 基 Y 基 Z 基 The spatial straight line equation in , that is, the spatial straight line equation of the rotation axis of the lower turntable and the rotation axis of the upper turntable motor side is determined in the same coordinate system.

[0057] Optionally, a micro translation adjustment stage with fluorescent microspheres and a substrate is fixed on the second rotation axis of the upper turntable, and the lower turntable motor is started and rotated 180 degrees so that the upper turntable encoder side and the upper turntable motor side are symmetrically interchanged to obtain the axial and radial runout values within a complete rotation cycle, and the spatial linear equations of the rotation axis of the lower turntable and the rotation axis of the upper turntable encoder side are determined in the first reference coordinate system. The spatial linear equations of the rotation axis of the lower turntable, the rotation axis of the upper turntable motor side, and the rotation axis of the upper turntable encoder side are determined in the same reference coordinate system, and the error detection within a complete rotation cycle is achieved, including:

[0058] Fix the micro translation adjustment stage with the fluorescent microsphere substrate on the second rotation axis of the upper turntable, start the lower turntable motor, and rotate it 180 degrees so that the upper turntable encoder side and the upper turntable motor side are symmetrically swapped. Similar to steps 12 and 13, the axial and radial runout values within a complete rotation cycle are obtained; in the first reference coordinate system X 基 Y 基 Z 基 The spatial straight line equations of the lower turntable rotation axis and the upper turntable encoder side rotation axis are determined, and the error detection of the lower turntable rotation axis, the upper turntable motor side rotation axis and the encoder side rotation axis within a complete rotation cycle is realized, and the lower turntable rotation axis, the upper turntable motor side rotation axis and the encoder side rotation axis are determined in the same first reference coordinate system X 基 Y 基 Z 基 The equation of the line in space.

[0059] In the second aspect, the present application also provides a device for detecting the axis error of the turntable of the rotary-axis laser tracker with the overall measurement optical path connected, which is used to perform the method for detecting the axis error of the turntable of the rotary-axis laser tracker with the overall measurement optical path connected as described in any one of the first aspects, including: a microscope, a fluorescent microsphere, a substrate, and a six-dimensional precision calibration displacement stage, wherein the microscope is located above the fluorescent microsphere, the fluorescent microsphere is fixed on the substrate, and the substrate is fixed on the six-dimensional precision calibration displacement stage.

[0060] This application has the following features and good effects:

[0061] This application realizes the determination of the spatial straight line equations of the upper and lower turntable axes of the rotary laser tracker connected with the overall measurement optical path in a coordinate system, as well as the detection of shaft diameter jump within a complete rotation cycle, laying the necessary technical foundation for realizing the compensation of the rotary axis error of the laser tracker turntable connected with the overall measurement optical path and improving the tracking accuracy and stability of the laser tracker.

[0062] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 A schematic diagram of the structure of the microscope structure and its own three-dimensional measurement calibration in the rotation axis error detection device of the rotary table of the rotary axis laser tracker provided in one embodiment of the present application;

[0064] Figure 2 A schematic diagram of the structure of a six-dimensional precision calibration stage in a rotary axis error detection device for a rotary axis laser tracker, provided in one embodiment of the present application, connected to an overall measurement optical path;

[0065] Figure 3 A schematic diagram of the structure of a rotation axis error detection device for a rotary table of a rotary axis laser tracker provided in one embodiment of the present application, with the overall measurement optical path connected;

[0066] Figure 4 This is a flow chart of a method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker provided in one embodiment of the present application;

[0067] In the figure: 1 objective lens, 2 cylindrical lens, 3 charge coupled image sensor, 4 imaging optical axis, 5 standard 45-degree beam splitter square mirror block, 6 beam splitter surface, 7 fluorescence excitation light source, 8 microscope, 9 fluorescent microspheres, 10 substrate, 11 six-dimensional precision calibration displacement stage, 12 bottom beam incident surface, 13 side beam incident surface, 14 focal longitudinal object plane, 15 upper turntable, 16 lower turntable, 17 lower turntable rotation axis, 18 first rotation axis, 19 second rotation axis, 20 lower turntable rotation axis, 21 motor side rotation axis, 22 encoder side rotation axis, 23 first gear, 24 second gear, 25 gear transmission shaft, 26 bracket, 27 bearing, 28 six-dimensional precision adjustment displacement stage, 29 micro translation adjustment stage. DETAILED DESCRIPTION

[0068] To make the purpose and technical solutions of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0069] See also Figure 1 and Figure 2 The present application provides a device for detecting the axis error of a rotary table of a rotary laser tracker with an overall measurement optical path connection, which may include: a microscope 8, a fluorescent microsphere 9, a substrate 10, and a six-dimensional precision calibration displacement stage 11, wherein the microscope 8 is located above the fluorescent microsphere 9, the fluorescent microsphere 9 is fixed on the substrate 10, and the substrate 10 is fixed on the six-dimensional precision calibration displacement stage 11.

[0070] As an example, the fluorescent microspheres 9 may be sub-millimeter fluorescent microspheres.

[0071] As an example, the substrate 10 may be a planar substrate.

[0072] As an example, a microscope 8 includes: an objective lens 1, a cylindrical lens 2, a charge coupled image sensor 3, a standard 45-degree beam splitting square mirror block 5 and a fluorescence excitation light source 7, wherein the cylindrical lens 2 is placed between the objective lens 1 and the charge coupled image sensor 3, the bottom surface of the cylindrical lens 2 is parallel to the charge coupled image sensor 3, and the edge where the semicircular cross section of the cylindrical lens 2 intersects with the bottom surface of the cylindrical lens 2 is parallel to the X-axis of the imaging surface of the charge coupled image sensor 3; a standard 45-degree beam splitting square mirror block 5 is placed under the objective lens 1, the standard 45-degree beam splitting square mirror block 5 includes a beam splitting surface 6, the beam splitting surface The light surface 6 is at a standard 45-degree angle to the bottom surface of the standard 45-degree beam splitting square mirror block, and the edge of the beam splitting surface 6 is parallel to the X-axis of the imaging surface of the charge-coupled image sensor 3. After being reflected or transmitted by the beam splitting surface 6, the fluorescent light beam can be incident on the objective lens 1 and received by the charge-coupled image sensor 3 after passing through the cylindrical lens 2. A fluorescent excitation light source 7 is placed on the mirror side at an angle of 45 degrees to the beam splitting surface 6. After the fluorescent excitation light source 7 is turned on, the light source light beam can be reflected or transmitted by the standard 45-degree beam splitting square mirror block 5; the imaging optical axis of the objective lens 1 passes through the center point of the beam splitting surface 6 of the standard 45-degree beam splitting square mirror block 5.

[0073] As an example, the microscope 8 may be a fluorescence microscope, the spatial position of the microscope 8 is fixed, and the microscope 8 has an astigmatic imaging function.

[0074] As an example, the objective lens 1 may include: an imaging optical axis 4 , and the normal vector of the imaging surface of the charge coupled image sensor 3 is parallel to the imaging optical axis 4 of the objective lens 1 .

[0075] As an example, the standard 45-degree beam splitting square mirror block 5 may further include a bottom beam incident surface 12 and a side beam incident surface 13. The bottom beam incident surface 12 is located at the bottom of the standard 45-degree beam splitting square mirror block 5 of the microscope 8, and the side beam incident surface 13 is located at the side of the standard 45-degree beam splitting square mirror block 5 of the microscope 8. The bottom beam incident surface 12 and the side beam incident surface 13 can be used to receive fluorescence.

[0076] As an example, the microscope 8 may further include: a focal longitudinal object plane 14, which is an object plane at the focus and perpendicular to the imaging optical axis, and the distance between the focal longitudinal object plane 14 and the center point of the beam splitter surface 6 is D.

[0077] As an example, see Figure 3 The overall measurement optical path is connected to the upper laser tracker turntable axis error detection device, and can also include: an upper turntable 15, a lower turntable 16, a lower turntable axis 17, and a six-dimensional precision adjustment displacement stage 28, wherein the lower turntable axis 17 is located above the lower turntable 16, the upper turntable 15 is located above the lower turntable 16, and the six-dimensional precision adjustment displacement stage 28 is located above the upper turntable 15.

[0078] As an example, the overall measurement optical path is connected to the laser tracker turntable axis error detection device, which can also include: a first gear 23, a second gear 24, a gear transmission shaft 25, a first rotating shaft 18, a second rotating shaft 19, a bracket 26, a bearing 27, and a micro translation adjustment platform 29, wherein the first gear 23 is fixed on the first rotating shaft 18, the second gear 24 is fixed on the second rotating shaft 19, and the first rotating shaft 18 and the second rotating shaft 19 are respectively fixed on both sides of the upper turntable 15; the gear transmission shaft 25 is arranged above the bracket 26, and the bracket 26 is fixed on the table surface of the lower turntable 16 On the upper part, the micro translation adjustment stage 29 is arranged on the bracket 26; when the lower turntable 16 rotates, it can drive the upper turntable 15 to rotate, and can also drive the bracket 26 to rotate. The bracket 26 is fixed to the gear transmission shaft 25 through a bearing 27, and the two ends of the gear transmission shaft 25 are respectively engaged with the first gear 23 and the second gear 24 on the upper turntable 15. When the first rotating shaft 18 of the upper turntable 15 rotates, the rotational force can be transmitted to the gear transmission shaft 25 through the first gear 23, so that the gear transmission shaft 25 rotates, and then drives the second gear 24 to rotate, thereby rotating the second rotating shaft 19.

[0079] As an example, the substrate 10 may be fixed on a micro translation adjustment stage 29 .

[0080] As an example, the first gear 23 may be a motor-side gear, and the second gear 24 may be an encoder-side gear.

[0081] As an example, the first rotating shaft 18 may be a motor-side rotating shaft, and the second rotating shaft 19 may be an encoder-side rotating shaft.

[0082] As an example, see Figure 3 The lower turntable 16 may include: a lower turntable rotation axis 20, and the lower turntable 16 rotates around the lower turntable rotation axis 20.

[0083] As an example, the microscope 8 for detecting the fluorescent microspheres 9 will not be touched by any object during the rotation of the upper turntable 15 and the lower turntable 16 .

[0084] As an example, see Figure 3 The overall measurement optical path is connected to the laser tracker turntable axis error detection device, and can also include: a motor side rotation axis 21, an encoder side rotation axis 22, wherein the first rotation axis 18 and the first gear 23 rotate with the motor side rotation axis 21 as the rotation center; the second rotation axis 19 and the second gear 24 rotate with the encoder side rotation axis 22 as the rotation center.

[0085] In one embodiment, see Figure 4The present application provides a method for detecting the rotation axis error of a laser tracker turntable on the overall measurement optical path connection. The method for detecting the rotation axis error of a laser tracker turntable on the overall measurement optical path connection may include the following steps: step S1 to step S14.

[0086] Step S1: Construct a microscope using an objective lens, a cylindrical lens, a charge-coupled image sensor, a standard 45-degree beam splitting square mirror block, and a fluorescence excitation light source.

[0087] Step S2: Setting up a microscope, fluorescent microspheres, a planar substrate, and a six-dimensional precision calibration stage to image the fluorescent microspheres on a charge-coupled image sensor.

[0088] Step S3: Make the six-dimensional precision calibration stage perform a non-parallel translational motion in two directions to obtain the three XY axis width ratios corresponding to the three images of the fluorescent microsphere before and after the movement on the charge-coupled image sensor, and determine the posture vector of the six-dimensional precision calibration stage corresponding to the three XY axis width ratios before and after the movement are the same.

[0089] Step S4: The six-dimensional precision calibration stage is moved back and forth along the direction of the posture vector, ensuring that the fluorescent microspheres can be imaged on the charge-coupled image sensor, thereby obtaining a functional relationship between the ratios of the fluorescent microspheres at different longitudinal object plane heights and the XY axis widths, i.e., a longitudinal object plane height function; the six-dimensional precision calibration stage is translated by an actual displacement value on each longitudinal object plane to determine the corresponding measured displacement value of the fluorescent microspheres imaged on the charge-coupled image sensor, and a microscope magnification function is obtained based on the actual displacement value and the measured displacement value.

[0090] Step S5: Fix the first gear and the second gear on the first rotating shaft and the second rotating shaft of the upper turntable respectively, and fix a bracket with a gear transmission shaft on one side on the table surface of the lower turntable.

[0091] Step S6: Fix the microscope on a six-dimensional precision adjustment platform, fix the substrate with fluorescent microspheres on the table of a micro translation adjustment platform, and fix the micro translation adjustment platform on the upper turntable, the first rotation axis, the second rotation axis and the lower turntable rotation axis in sequence.

[0092] Step S7: Fix the micro translation adjustment stage with fluorescent microspheres and substrate on the lower turntable shaft, start the lower turntable motor, rotate the lower turntable shaft to a minimum step angle and then stop, record the imaging of the fluorescent microspheres by the microscope, determine the center of mass coordinates and XY axis width ratio under the imaging plane coordinates of the charge-coupled image sensor through a two-dimensional Gaussian function, determine the microscope magnification corresponding to the longitudinal object plane height of the fluorescent microspheres according to the XY axis width ratio, and determine the spatial coordinate value of the fluorescent microspheres mapped to the imaging plane coordinates of the charge-coupled image sensor according to the center of mass coordinates and the microscope magnification.

[0093] Step S8: construct a first reference coordinate system according to the spatial coordinate values, determine the spatial linear equation of the lower turntable rotation axis in the first reference coordinate system, and obtain the radial runout value of the lower turntable rotation axis within a complete rotation cycle.

[0094] Step S9: Set the lower turntable shaft 17 to be stationary, record the spatial coordinate value of the fluorescent microsphere in the first reference coordinate system at this time, construct the motion coordinate system of the six-dimensional precision adjustment displacement stage, determine the first vector value of the unit vector on the X-axis of the motion coordinate system in the first reference coordinate system, determine the first coordinate value of the origin of the motion coordinate system in the first reference coordinate system, rotate the six-dimensional precision adjustment displacement stage around the X-axis of the motion coordinate system by a first angle, and rotate the unit vector in the first reference coordinate system around the first vector value by the first angle to obtain a second vector value.

[0095] Step S10: Rotate the first reference coordinate system around the X-axis of the motion coordinate system by the first angle to obtain the measurement coordinate system of the microscope, determine the spatial coordinate values of the fluorescent microspheres in the measurement coordinate system, and obtain the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment translation stage rotates by the first angle.

[0096] Step S11: Rotate the six-dimensional precision adjustment translation stage back to the starting posture, determine the third vector value of the unit vector on the Y-axis of the motion coordinate system of the six-dimensional precision adjustment translation stage in the first reference coordinate system, rotate the six-dimensional precision adjustment translation stage around the Y-axis of the motion coordinate system by a second angle, obtain the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment translation stage rotates by the second angle, and obtain the first vector value, first coordinate value, and third vector value through the least squares method.

[0097] Step S12: Fix the micro translation adjustment platform with fluorescent microspheres and substrate on the first rotating shaft of the upper turntable, start the motor of the upper turntable to control the rotation of the first rotating shaft, construct a second reference coordinate system, and determine the spatial straight line equation of the rotation axis of the upper turntable motor side in the second reference coordinate system to obtain the axial and radial runout values within a complete rotation cycle.

[0098] Step S13: Determine the yaw angle and pitch angle of the second reference coordinate system relative to the first reference coordinate system based on the six-dimensional precision adjustment translation stage, convert the unit vector in the first reference coordinate system into the yaw angle and pitch angle, obtain the spatial coordinate value of the fluorescent microsphere in the second reference coordinate system in the first reference coordinate system, and convert the spatial straight line equation of the rotation axis of the upper turntable into the spatial straight line equation in the first coordinate system.

[0099] Step S14: Fix the micro translation adjustment table with fluorescent microspheres and substrate on the second rotating shaft of the upper turntable, start the lower turntable motor, rotate 180 degrees to symmetrically exchange the positions of the upper turntable encoder side and the upper turntable motor side, and obtain the axial and radial runout values within a complete rotation cycle, and determine the spatial linear equations of the lower turntable rotation axis and the upper turntable encoder side rotation axis in the first reference coordinate system, so as to realize the determination of the spatial linear equations of the lower turntable rotation axis, the upper turntable motor side rotation axis and the upper turntable encoder side rotation axis in the same reference coordinate system and the error detection within a complete rotation cycle.

[0100] The overall measurement optical path of the present application is connected to the laser tracker turntable axis error detection method. By using a microscope constructed with components such as an objective lens and a cylindrical lens, and combining fluorescent microspheres as measurement marks, the imaging characteristics at different object plane heights and displacements are analyzed to establish a longitudinal object plane height function and a microscopic magnification function, providing an accurate measurement basis for subsequent error detection; in the turntable axis error detection process, by fixing the fluorescent microsphere substrate on the lower turntable axis and the first and second rotation axes of the upper turntable respectively, combined with multi-coordinate system conversion and spatial linear equation construction, the radial runout value, axial runout value and other error parameters of each rotation axis of the lower turntable and the upper turntable can be comprehensively detected; through the rotation of the second translation stage and the coordinate system conversion, the detection of the rotation axis errors of the motor side and the encoder side of the upper turntable is realized in the same reference coordinate system, eliminating the errors caused by different measurement bases, improving the accuracy and comparability of the detection results, and being able to effectively detect various errors of the turntable axis within a complete rotation cycle, providing reliable technical support for the high-precision manufacturing and calibration of the laser tracker turntable.

[0101] In step S1, see Figure 4 In step S1, a microscope is constructed using an objective lens, a cylindrical lens, a charge-coupled image sensor, a standard 45-degree beam splitting square mirror block, and a fluorescence excitation light source.

[0102] As an example, see Figure 1A microscope 8 with astigmatic imaging capability, fixed in spatial position, is constructed using an objective lens 1, a cylindrical lens 2, a charge-coupled image sensor 3, a standard 45-degree beamsplitting square mirror block 5, and a fluorescence excitation light source 7. Specifically, the cylindrical lens 2 is placed between the objective lens 1 and the charge-coupled image sensor 3. The bottom surface of the cylindrical lens 2 is parallel to the charge-coupled image sensor 3, and the edge where the semicircular cross-section of the cylindrical lens 2 intersects the bottom surface of the cylindrical lens 2 is parallel to the X-axis of the imaging surface of the charge-coupled image sensor 3. The normal vector of the imaging surface of the charge-coupled image sensor 3 is parallel to the imaging optical axis 4 of the objective lens 1. A standard 45-degree beam splitting square mirror block 5 is placed under the objective lens 1. The edge of the 45-degree beam splitting surface 6 of the standard 45-degree beam splitting square mirror block 5 is parallel to the X-axis of the imaging surface of the charge coupled image sensor 3. The fluorescent light beam can be reflected or transmitted by the 45-degree beam splitting surface 6 of the standard 45-degree beam splitting square mirror block, enter the objective lens 1, and be received by the charge coupled image sensor 3 after passing through the cylindrical lens 2. A fluorescent excitation light source 7 is placed on the mirror side that forms an angle of 45 degrees with the 45-degree beam splitting surface 6. The coordinate value of the intersection of the objective lens imaging optical axis 4 and the imaging surface of the charge coupled image sensor 3 in its imaging surface plane coordinate system is ( x o , y o ), and the imaging optical axis 4 of the objective lens 1 passes through the center point of the 45-degree splitting surface 6 of the standard 45-degree splitting square mirror block 5, and the distance between the focal longitudinal object plane 14 of the microscope 8 (the object plane perpendicular to the imaging optical axis at the focus) and the center point of the 45-degree splitting surface 6 is D.

[0103] As an example, the microscope 8 may be a fluorescence microscope.

[0104] In step S2, see Figure 4 In step S2, a microscope, fluorescent microspheres, a planar substrate, and a first translation stage are set to image the fluorescent microspheres on a charge-coupled image sensor.

[0105] As an example, a submillimeter fluorescent microsphere 9 is affixed to a planar substrate 10, which is then parallely affixed to a six-dimensional precision calibration stage 11. The six-dimensional precision calibration stage 11 with the substrate 10 is placed below the beam incident surface 12 at the bottom of a standard 45-degree beamsplitting square mirror 5 under a microscope 8 with astigmatism imaging capabilities. After the fluorescence excitation light source 7 is turned on, the light beam is reflected by the standard 45-degree beamsplitting square mirror 5 and then irradiated onto the fluorescent microsphere 9, causing it to emit fluorescence. After being transmitted through the standard 45-degree beamsplitting square mirror 5, the fluorescent microsphere 9 can be imaged on the charge-coupled image sensor 3.

[0106] In step S3, see Figure 4In step S3, the six-dimensional precision calibration stage is subjected to a non-parallel translational motion in two directions to obtain the three XY-axis width ratios corresponding to the three images of the fluorescent microsphere before and after the movement on the charge-coupled image sensor, and the posture vector of the six-dimensional precision calibration stage corresponding to the three XY-axis width ratios before and after the movement are determined to be the same.

[0107] As an example, fitting the imaging light intensity of fluorescent microspheres 9 with a two-dimensional Gaussian function not only determines the imaging centroid position, but also the width of the imaging light intensity distribution along the X and Y axes of the imaging plane of the charge-coupled image sensor 3. This in turn yields the XY width ratio of the fluorescent microspheres 9. This XY width ratio includes the width ratio in the X-axis direction and the width ratio in the Y-axis direction. Due to the astigmatic imaging effect of the cylindrical lens 2, the XY width ratio of the fluorescent microspheres 9 varies in different longitudinal object planes (the imaging object plane perpendicular to the imaging optical axis).

[0108] As an example, the six-dimensional precision calibration stage 11 is subjected to two non-parallel translational motions to obtain the three XY-axis width ratios corresponding to the three images of the fluorescent microsphere 9 before and after the motion on the charge-coupled image sensor 3. If these three XY-axis width ratios are the same, it means that the plane defined by the two translational motion directions is a longitudinal object plane of the fluorescence microscope. The six-dimensional precision calibration stage 11 is traversed through the pitch and yaw postures with a minimum step size. The above-mentioned translation motion is performed in each posture, and the corresponding three XY-axis width ratios are obtained. From these, the posture vector ( ) of the six-dimensional precision calibration stage 11 corresponding to the three XY-axis width ratios before and after the motion are the same is determined. m , n , q ), which is the vector value in the six-dimensional precision calibration stage’s own motion coordinate system.

[0109] As an example, the posture vector ( m , n , q ) is the normal vector of a longitudinal object plane of the determined fluorescence microscope and is also the vector of the imaging optical axis 4.

[0110] In step S4, see Figure 4 In step S4, the six-dimensional precision calibration stage is moved back and forth along the direction of the posture vector, ensuring that the fluorescent microspheres can be imaged on the charge-coupled image sensor, thereby obtaining a functional relationship between the ratios of the fluorescent microspheres at different longitudinal object plane heights and the XY axis widths, i.e., a longitudinal object plane height function. The six-dimensional precision calibration stage is translated by an actual displacement value on each longitudinal object plane to determine a corresponding measured displacement value of the fluorescent microspheres imaged on the charge-coupled image sensor. A microscope magnification function is obtained based on the actual displacement value and the measured displacement value.

[0111] As an example, the six-dimensional precision calibration stage 11 is moved along the posture vector ( m , n , q ) direction, and ensure that the fluorescent microsphere 9 can be imaged on the charge coupled image sensor 3, and obtain the functional relationship between the ratio of the fluorescent microsphere 9 at different longitudinal object plane heights (relative to the focal longitudinal object plane) and the XY axis width, that is, the longitudinal object plane height function f ( w ),in, w is the XY axis width ratio variable of the fluorescent microsphere 9.

[0112] As an example, the six-dimensional precision calibration stage 11 is translated by an actual displacement value on each longitudinal object plane, and the measured displacement value of the fluorescent microsphere 9 is obtained on the charge-coupled image sensor 3. The measured displacement value of the fluorescent microsphere 9 is divided by the actual displacement value of the six-dimensional precision calibration stage 11 to obtain the microscopic magnification value on each longitudinal object plane.

[0113] As an example, the microscopic magnification value is different for different longitudinal object plane heights, and the microscopic magnification value can be a function value related to the longitudinal object plane height or the XY axis width ratio, and the microscopic magnification function is: N ( w ),in, w is the XY axis width ratio variable of the fluorescent microsphere 9. Since the standard 45-degree beam splitting square mirror block 5 has a mirror symmetry, the longitudinal object plane height function corresponding to the side beam incident surface 13 of the standard 45-degree beam splitting square mirror block 5 can be obtained. f ( w ) and microscope magnification function N ( w ).

[0114] In step S5, see Figure 4 In step S5, the first gear and the second gear are fixed to the first rotating shaft and the second rotating shaft of the upper turntable respectively, and a bracket with a gear transmission shaft on one side is fixed to the table surface of the lower turntable.

[0115] As an example, see Figure 3 The first gear and the second gear are respectively fixed on the first side rotating shaft 18 and the second rotating shaft 19 of the upper turntable 15 of the laser tracker, and a bracket 26 with a gear transmission shaft 25 on one side is fixed on the table surface of the lower turntable 16 of the laser tracker.

[0116] For example, when the lower turntable 16 rotates, it drives the upper turntable 15 and the bracket 26 to rotate. The bracket 26 is fixed to the gear transmission shaft 25 via a bearing. The ends of the gear transmission shaft 25 respectively engage with the first gear 23 and the second gear 24 of the upper turntable 15. When the first rotating shaft 18 of the upper turntable 15 rotates, the rotational force is transmitted to the gear transmission shaft 25 via the motor-side gear 23, causing the gear transmission shaft 25 to rotate, which in turn drives the second gear 24 to rotate, thereby rotating the second side rotating shaft 19.

[0117] As an example, the first gear 23 may be a motor-side gear, and the second gear 24 may be an encoder-side gear.

[0118] As an example, the first rotating shaft 18 may be a motor-side rotating shaft, and the second rotating shaft 19 may be an encoder-side rotating shaft.

[0119] In step S6, refer to Figure 4 In step S6, the microscope is fixed on a six-dimensional precision adjustment displacement stage, the substrate with fluorescent microspheres is fixed on the table of a micro translation adjustment stage, and the micro translation adjustment stage is fixed on the upper turntable, the first rotation axis, the second rotation axis and the lower turntable rotation axis in sequence.

[0120] As an example, see Figure 3 The microscope 8 with astigmatism imaging function is fixed on a six-dimensional precision adjustment stage 28, and the substrate 10 with fluorescent microspheres 9 is fixed on the surface of a micro-translation adjustment stage 29. The micro-translation adjustment stage 29 can fine-tune the spatial position of the fluorescent microspheres 9. The micro-translation adjustment stage 29 is fixed to the first rotation axis 18 and the second rotation axis 19 of the upper turntable 15 and the rotation axis 17 of the lower turntable in sequence.

[0121] As an example, each time the micro-translation adjustment stage 29 is fixed, the upper or lower turntable motor is activated to rotate the corresponding rotation axis one revolution, ensuring that the fluorescent microspheres 9 are imaged by the microscope 8 during the entire rotation of the rotation axis. The coordinates of the center of mass of the Gaussian fit of the imaging are variable in the plane coordinates of the imaging surface of the charge-coupled image sensor 3. This ensures that the fluorescent microspheres 9 are not exactly on the rotation axis, and that the microscope 8, which performs astigmatic imaging, is not touched by any objects during the rotation of the upper and lower turntables 15 and 16.

[0122] As an example, when the lower turntable rotates to form an image, the bottom beam incident surface 12 of the standard 45-degree beam splitting square mirror block 5 receives fluorescence; when the upper turntable 15 rotates to form an image, the side beam incident surface 13 of the standard 45-degree beam splitting square mirror block 5 receives fluorescence.

[0123] In step S7, refer to Figure 4In step S7, a micro translation adjustment stage with fluorescent microspheres and a substrate is fixed to a lower turntable shaft, a lower turntable motor is started, and the lower turntable shaft is rotated to a minimum step angle and then remains stationary. The imaging of the fluorescent microspheres by the microscope is recorded, and the centroid coordinates and the XY axis width ratio in the imaging plane coordinates of the charge-coupled image sensor are determined by a two-dimensional Gaussian function. The microscopic magnification corresponding to the longitudinal object plane height of the fluorescent microspheres is determined based on the XY axis width ratio. The spatial coordinate value of the fluorescent microspheres mapped to the imaging plane coordinates of the charge-coupled image sensor is determined based on the centroid coordinates and the microscopic magnification.

[0124] As an example, the micro-translation adjustment stage 29 with the substrate 10 of the fluorescent microspheres 9 is fixed again on the lower turntable shaft 17, and the lower turntable motor is started to rotate the lower turntable shaft 17 to a minimum step angle and then stop. Then, the image of the fluorescent microspheres 9 by the microscope 8 with the astigmatic imaging function is recorded. The imaging light intensity is fitted with a two-dimensional Gaussian function to obtain the center of mass coordinates and the XY axis width ratio in the imaging plane coordinates of the charge-coupled image sensor 3. The XY axis width ratio can be used to determine the microscope magnification function corresponding to the longitudinal object plane height of the fluorescent microspheres 9 at this time. N ( w The centroid coordinates are divided by the microscopic magnification to obtain the spatial coordinate values of the fluorescent microspheres 9 mapped to the imaging plane coordinates of the charge coupled image sensor 3.

[0125] As an example, by rotating the lower turntable 16 one circle, a corresponding series of spatial coordinate values of the fluorescent microspheres 9 can be obtained. These spatial coordinate values of the fluorescent microspheres 9 are fitted with a plane ellipse function to obtain the plane mapping spatial trajectory drawn by the rotation of the axis through the fluorescent microspheres 9, and the length values of the major and minor axes of the fitted ellipse at this time are recorded. The pitch posture and yaw posture of the six-dimensional precision adjustment displacement stage 28 are traversed with the minimum step size, and a length value of the major and minor axes of the fitted ellipse can be obtained for each posture.

[0126] As an example, when the major axis and minor axis of the fitted ellipse corresponding to a certain posture are the minimum values among all traversed postures, that is, when the rotation axis is perpendicular to the imaging plane, the length of the mapped spatial plane trajectory is the shortest. At this time, the rotation axis 20 of the lower turntable is parallel to the imaging optical axis 4 of the microscope 8.

[0127] As an example, the plane ellipse function fitting may adopt a general ellipse function in which the major and minor axes of the ellipse are not parallel to the coordinate axes.

[0128] In step S8, refer to Figure 4 In step S8, a first reference coordinate system is constructed according to the spatial coordinate values, and the spatial linear equation of the rotation axis of the lower turntable is determined in the first reference coordinate system to obtain the radial runout value of the lower turntable rotation axis within a complete rotation cycle.

[0129] As an example, in the case where the rotation axis 20 of the lower turntable is parallel to the imaging optical axis 4 of the microscope 8, on the premise that the imaging light intensity of the fluorescent microsphere 9 corresponding to all step rotations of the lower turntable and its imaging plane coordinates of the charge-coupled image sensor 3 are obtained, the center of mass coordinates and the XY axis width ratio in the imaging plane coordinates of the charge-coupled image sensor 3 are obtained by two-dimensional Gaussian fitting of the imaging light intensity. The corresponding longitudinal object plane height value and microscope magnification are obtained by the XY axis width ratio. The center of mass coordinates are divided by the microscope magnification to obtain the spatial coordinate values of the fluorescent microsphere 9 mapped to the imaging plane coordinates of the charge-coupled image sensor 3. Let the center coordinates obtained by fitting these spatial coordinate values with the spatial elliptic function be ( x 拟 , y 拟 ), the origin of the coordinate system of the imaging plane of the charge coupled image sensor 3 is translated to the coordinate of the intersection of the imaging optical axis 4 of the microscope and the imaging plane of the charge coupled image sensor 3 ( x o , y o ), and then translates to the longitudinal object plane 14 along the imaging optical axis 4. The corresponding coordinate system is recorded as the first reference coordinate system X 基 Y 基 Z 基 , the first reference coordinate system is the measurement coordinate system of the microscope 8 at this time.

[0130] Furthermore, the spatial coordinate value of the fluorescent microsphere 9 mapped to the imaging plane coordinate of the charge coupled image sensor 3 is subtracted from the intersection coordinate ( x o , y o ), get the first reference coordinate system X 基 Y 基 Z 基 The XY coordinate value of the fluorescent microsphere 9 in the middle, and the obtained vertical object plane height value is the first reference coordinate system X 基 Y 基 Z 基 At this point, it can be obtained that the rotation axis 20 of the lower turntable is the first reference coordinate system X 基 Y 基 Z 基 Pass ( x 拟 - x o , y 拟 - y o ,0) and with (0,0,1) as the direction.

[0131] As an example, in the first reference coordinate system X 基 Y 基 Z 基 In the figure, all axial runout values within a complete rotation cycle of the lower turntable shaft 17 can be calculated as the difference between the Z-axis value of the fluorescent microsphere 9 corresponding to each rotation step angle of the lower turntable shaft 17 and the Z-axis value of the fluorescent microsphere 9 when the lower turntable shaft 17 is not rotating. The radial runout value within a complete rotation cycle of the lower turntable shaft 17 can be calculated as the difference between the distance from the XY-axis plane coordinate of the fluorescent microsphere 9 corresponding to each rotation step angle of the lower turntable shaft 17 to the origin and the distance from the coordinate point on the fitted plane ellipse function corresponding to this rotation step angle to the origin.

[0132] In step S9, refer to Figure 4 In step S9, the lower turntable shaft 17 is set to be stationary, the spatial coordinate value of the fluorescent microsphere in the first reference coordinate system at this time is recorded, the motion coordinate system of the six-dimensional precision adjustment displacement stage is constructed, the first vector value of the unit vector on the X-axis of the motion coordinate system in the first reference coordinate system is determined, the first coordinate value of the origin of the motion coordinate system in the first reference coordinate system is determined, the six-dimensional precision adjustment displacement stage is rotated around the X-axis of the motion coordinate system by a first angle, and the unit vector in the first reference coordinate system is rotated around the first vector value by the first angle to obtain a second vector value.

[0133] As an example, ensure that the lower turntable shaft 17 is stationary, and record the fluorescent microspheres 9 at the first reference coordinate system X. 基 Y 基 Z 基 The spatial coordinate values in . Construct the motion coordinate system X of the six-dimensional precision adjustment translation stage 28 调 Y 调 Z 调 , assuming that the motion coordinate system X of the six-dimensional precision adjustment translation stage 28 调 Y 调 Z 调 The unit vector on the X axis of the first reference coordinate system X 基 Y 基 Z 基 The first vector value in is ( u X , u Y ,u Z ), motion coordinate system X 调 Y 调 Z 调 The origin of the first reference coordinate system X 基 Y 基 Z 基 The first coordinate value in is ( o X , oY ,o Z ), so that the six-dimensional precision adjustment translation stage 28 moves around the motion coordinate system X 调 Y 调 Z 调 The X axis is rotated a small first angle θ , that is, in the motion coordinate system X 基 Y 基 Z 基 The first vector value ( u X , u Y ,u Z ) Rotate to the first angle θ . Set the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0), and (0,0,1) in the vector are rotated around the first vector value ( u X , u Y ,u Z ) Rotate to the first angle θ .

[0134] As an example, the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in the first coordinate value ( o X , o Y ,o Z ) are subtracted and then right-multiplied by the first rotation transformation matrix to obtain the unit vectors (1,0,0), (0,1,0) and (0,0,1) around the first vector value ( u X , u Y ,u Z ) Rotate to the first angle θ Then in the first reference coordinate system X 基 Y 基 Z 基 The corresponding second vector value in .

[0135] As an example, the expression of the first rotation transformation matrix is:

[0136]

[0137] in,u X 、 u Y 、 u Z are the X-axis, Y-axis, and Z-axis values of the first vector value, θ The first angle.

[0138] As an example, the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in the first coordinate value ( o X , o Y ,o Z ) and subtract it to get (1- o X , - o Y , - o Z )、(- o X , 1- o Y , - o Z )and(- o X , - o Y , 1- o Z ), and then right-multiply the first rotation transformation matrix to obtain the second vector value, and then respectively multiply the second vector value with the first coordinate value ( o X , o Y ,o Z ) are added together to obtain ( i x , i y , i z )、( j x , j y , j z )and( k x , k y , k z). Compare the origin coordinate (0, 0, 0) with the first coordinate value ( o X , o Y ,o Z ) and then right-multiply it by the first rotation transformation matrix, and then add it to the first coordinate value ( o X , o Y ,o Z ) add up to get ( t x , t y , t z ), then in the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) are rotated around the first vector value ( u X , u Y ,u Z ) Rotate to the first angle θ Then in the first reference coordinate system X 基 Y 基 Z 基 The second vector values in are ( i x - t x , i y - t y , i z - t z )、( j x - t x , j y - t y , j z - t z )and( k x - t x , k y - t y , k z -t z ).

[0139] In step S10, refer to Figure 4 Step S10, step S10: rotate the first reference coordinate system around the X-axis of the motion coordinate system by the first angle to obtain the measurement coordinate system of the microscope, determine the spatial coordinate values of the fluorescent microspheres in the measurement coordinate system, and obtain the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment translation stage rotates by the first angle.

[0140] As an example, the six-dimensional precision adjustment stage 28 moves around the motion coordinate system X 调 Y 调 Z 调 The X axis is rotated a small first angle θ , driving the microscope 8 to move around the coordinate system X 调 Y 调 Z 调 The X axis is rotated a small first angle θ At this time, the first reference coordinate system X 基 Y 基 Z 基 Also around the motion coordinate system X 调 Y 调 Z 调 The X axis is rotated a small first angle θ , get the measurement coordinate system X of microscope 8 θ Y θ Z θ .

[0141] As an example, the first reference coordinate system X in step S8 基 Y 基 Z 基 The measurement coordinate system of the microscope 8 is similar, and the measurement coordinate system X of the fluorescent microsphere 9 in the microscope 8 can be obtained. θ Y θ Z θ The spatial coordinate values in ( x θ , y θ , z θ ), so far, the spatial coordinate relationship of the fluorescent microsphere 9 before and after the six-dimensional precision adjustment displacement stage 28 is obtained, and the expression is as follows:

[0142]

[0143] in,( x θ , y θ , zθ ) is the measurement coordinate system X of the fluorescent microsphere 9 on the microscope 8 θ Y θ Z θ The spatial coordinate value in ; ( i x - t x , i y - t y , i z - t z ), ( j x - t x , j y - t y , j z - t z )and( k x - t x , k y - t y , k z - t z ) are the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) are rotated around the first vector value ( u X , u Y ,u Z ) Rotate to the first angle θ Then in the first reference coordinate system X 基 Y 基 Z 基 The second vector value in ; The fluorescent microspheres 9 are in the first reference coordinate system X when the lower turntable shaft 17 is stationary. 基 Y 基 Z 基 The spatial coordinate values in .

[0144] In step S11, refer to Figure 4In step S11, the six-dimensional precision adjustment stage is rotated back to the starting posture, the third vector value of the unit vector on the Y-axis of the motion coordinate system of the six-dimensional precision adjustment stage in the first reference coordinate system is determined, and the six-dimensional precision adjustment stage is rotated around the Y-axis of the motion coordinate system by a second angle to obtain the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment stage is rotated by the second angle, and the first vector value, the first coordinate value, and the third vector value are obtained by the least squares method.

[0145] As an example, the six-dimensional precision adjustment stage 28 is rotated back to the starting posture of step S9. Assuming that the motion coordinate system X of the six-dimensional precision adjustment stage 28 is 调 Y 调 Z 调 The unit vector on the Y axis of the first reference coordinate system X 基 Y 基 Z 基 The third vector value in is ( v X , v Y ,v Z ), so that the six-dimensional precision adjustment translation stage 28 moves around the motion coordinate system X 调 Y 调 Z 调 The Y axis is rotated by a small second angle δ .

[0146] As an example, similarly, we can also obtain a spatial coordinate relationship of the fluorescent microsphere 9 before and after the six-dimensional precision adjustment stage 28 rotates, which is similar to expression (II). So far, we can obtain six relationships about nine unknown quantities, namely, the first vector value ( u X , u Y ,u Z ), the first coordinate value ( o X , o Y ,o Z ) and the third vector value ( v X , v Y ,v Z ) six relations.

[0147] Further, repeat step S9 to step S11 to rotate more different first angles θ and the second angle δ, so that we can obtain more relations than the number of nine unknowns, thus being able to build an overdetermined system of equations, and calculate the first vector value ( u X , u Y ,u Z ), the first coordinate value ( o X , o Y ,o Z ) and the third vector value ( v X , v Y ,v Z ).

[0148] In step S12, refer to Figure 4 In step S12, the micro translation adjustment stage with fluorescent microspheres and substrate is fixed on the first rotating shaft of the upper turntable, the motor of the upper turntable is started to control the rotation of the first rotating shaft, and a second reference coordinate system is constructed. The spatial linear equation of the rotation axis on the motor side of the upper turntable is determined in the second reference coordinate system to obtain the axial and radial runout values within a complete rotation cycle.

[0149] As an example, the micro translation adjustment stage 29 with the fluorescent microsphere 9 substrate 10 is fixed on the first rotation axis 18 of the upper turntable 15, and the upper turntable 15 motor is started to control the rotation of the first rotation axis 18. The remaining operations are the same as steps S7 and S8. At this time, the measurement coordinate system of the microscope 8 is X' 基 Y' 基 Z' 基 , that is, the second reference coordinate system is X' 基 Y' 基 Z' 基 .

[0150] As an example, the imaging fluorescence of the fluorescent microsphere 9 is transmitted to the side beam incident surface 13 of the standard 45-degree beam splitting square mirror block 5 to form an image. Due to the mirror effect of the beam splitting surface 6 of the standard 45-degree beam splitting square mirror block 5, the symmetrical mirror image of the fluorescent microsphere 9 is obtained in the second reference coordinate system X'. 基 Y' 基 Z' 基 The spatial coordinate values in are uniformly expressed as ( x’ , y’, z’ Since the distance between the focal longitudinal object plane 14 of the microscope 8 and the center point of the 45-degree beam splitter 6 is known as D in step S1, the actual fluorescent microsphere 9 can be obtained in the second reference coordinate system X' 基 Y'基 Z' 基 The spatial coordinate values in are ( x’ , y’ -D ,z’ +D), similar to step S8, in the second reference coordinate system X' 基 Y' 基 Z' 基 In the equation, the spatial straight line equation of the motor side rotation axis 21 of the upper turntable 15 and the axial and radial runout values within a complete rotation cycle can be obtained.

[0151] In step S13, refer to Figure 4 In step S13, the yaw angle and pitch angle of the second reference coordinate system relative to the first reference coordinate system are determined based on the six-dimensional precision adjustment translation stage, the unit vector in the first reference coordinate system is converted into the yaw angle and pitch angle, the spatial coordinate value of the fluorescent microsphere in the second reference coordinate system in the first reference coordinate system is obtained, and the spatial straight line equation of the rotation axis of the upper turntable is converted into the spatial straight line equation in the first coordinate system.

[0152] As an example, since the second reference coordinate system X' 基 Y' 基 Z' 基 It is also determined by the principle that the length of the spatial plane trajectory of the image mapped when the rotation axis is perpendicular to the imaging plane is the shortest, so the second reference coordinate system X' 基 Y' 基 Z' 基 With the first reference coordinate system X 基 Y 基 Z 基 There will be posture differences, which are due to the difference in the first reference coordinate system X 基 Y 基 Z 基 The corresponding six-dimensional precision adjustment displacement stage 28 posture is based on the second reference coordinate system X' 基 Y' 基 Z' 基 The corresponding six-dimensional precision adjustment displacement stage 28 has a yaw angle θ' (i.e. around the motion coordinate system X 调 Y 调 Z 调 X-axis rotation) and pitch angle δ' (i.e. around the motion coordinate system X 调 Y 调 Z 调 Y-axis rotation).

[0153] As an example, the yaw angle and the pitch angle can be determined by the six-dimensional precision adjustment stage 28, and the first reference coordinate system X is 基 Y 基 Z基 deflection θ' and pitch δ' After the angle is changed to the second reference coordinate system X' 基 Y' 基 Z' 基 , the corresponding second rotation transformation matrix that needs to be right multiplied is:

[0154]

[0155] in, θ' is the deflection angle, δ' is the pitch angle, ( u X , u Y ,u Z ) is the motion coordinate system X of the six-dimensional precision adjustment translation stage 28 调 Y 调 Z 调 The unit vector on the X axis of the first reference coordinate system X 基 Y 基 Z 基 The first vector value in , ( v X , v Y ,v Z ) is the motion coordinate system X of the six-dimensional precision adjustment translation stage 28 调 Y 调 Z 调 The unit vector on the Y axis of the first reference coordinate system X 基 Y 基 Z 基 The third vector value in .

[0156] As an example, the second rotation transformation matrix is a known quantity, and the second rotation transformation matrix and the motion coordinate system X are used to calculate the value of the second rotation transformation matrix. 调 Y 调 Z 调 The origin of the first reference coordinate system X 基 Y 基 Z 基 The first coordinate value in ( o X , o Y ,o Z ). Similar to the operation in step S9, the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0), (0,0,1) and the origin (0,0,0) are converted to ( i'x , i' y , i' z )、( j' x , j' y , j' z )、( k' x , k' y , k' z )and( t' x , t' y , t' z ), so that the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in θ' and pitch δ' After the angle is set, in the first reference coordinate system X 基 Y 基 Z 基 becomes ( i' x - t' x , i' y - t' y , i' z - t' z )、( j' x - t' x , j' y - t' y , j' z - t' z )and( k' x - t' x , k' y - t' y , k' z - t' z), so far the fluorescent microsphere 9 can be obtained in the second reference coordinate system X' 基 Y' 基 Z' 基 The spatial coordinates in x’ , y’ -D ,z’ +D) corresponds to the first reference coordinate system X 基 Y 基 Z 基 The spatial coordinate values in ( x’ 基 , y’ 基 , z’ 基 ), the expression is:

[0157]

[0158] Where D represents the distance between the focal longitudinal object plane of the microscope and the center point of the beam splitter surface.

[0159] As an example, the second reference coordinate system X' 基 Y' 基 Z' 基 After the coordinates of any two points on the space straight line equation of the upper turntable 15 motor side rotation axis 21 are converted by expression (Ⅳ), their coordinates in the first reference coordinate system X can be obtained. 基 Y 基 Z 基 The coordinate values in the first reference coordinate system X 基 Y 基 Z 基 The spatial straight line equation in , that is, the spatial straight line equation of the lower turntable rotation axis 20 and the upper turntable motor side rotation axis 21 is determined in the same coordinate system.

[0160] In step S14, refer to Figure 4 In step S14, the micro translation adjustment stage with fluorescent microspheres and substrate is fixed on the second rotating shaft of the upper turntable, and the lower turntable motor is started, and rotated 180 degrees to symmetrically exchange the positions of the upper turntable encoder side and the upper turntable motor side, so as to obtain the axial and radial runout values within a complete rotation cycle, and determine the spatial linear equations of the lower turntable rotation axis and the upper turntable encoder side rotation axis in the first reference coordinate system, so as to realize the determination of the spatial linear equations of the lower turntable rotation axis, the upper turntable motor side rotation axis and the upper turntable encoder side rotation axis in the same reference coordinate system and the error detection within a complete rotation cycle.

[0161] As an example, a micro translation adjustment stage 29 with a substrate 10 of fluorescent microspheres 9 is fixed on the second rotating shaft 19 of the upper turntable 15, and the lower turntable motor is started and rotated 180 degrees so that the encoder side of the upper turntable 15 and the upper turntable motor side are symmetrically swapped. Similar to steps S12 and S13, the axial and radial runout values within a complete rotation cycle are obtained.

[0162] Furthermore, in the first reference coordinate system X 基 Y 基 Z 基 The spatial straight line equations of the lower turntable rotation axis 20 and the upper turntable 15 encoder side rotation axis 22 are determined. Thus, the error detection of the lower turntable rotation axis 20, the upper turntable 15 motor side rotation axis 21 and the encoder side rotation axis 22 within a complete rotation cycle is achieved, and the lower turntable rotation axis 20, the upper turntable 15 motor side rotation axis 21 and the encoder side rotation axis 22 are determined in the same first reference coordinate system X. 基 Y 基 Z 基 The equation of the line in space.

[0163] In the turntable axis error detection method of the rotary table laser tracker of the overall measurement optical path connection of the present application, the astigmatism effect is introduced by the cylindrical lens, and the functional relationship between the XY axis width ratio of the fluorescent microsphere imaging and the longitudinal object plane height, as well as the microscopic magnification function of the actual displacement and the measured displacement are established, providing an accurate measurement basis for subsequent error detection; in the turntable axis error detection process, by fixing the fluorescent microsphere substrate on the lower turntable axis, the motor side and the encoder side axis of the upper turntable respectively, combining the multi-coordinate system conversion and the construction of the spatial linear equation, the radial runout value, axial runout value and other error parameters of each axis can be fully detected; by adjusting the rotation of the six-dimensional precision displacement stage and coordinate system conversion, the detection of the rotation axis errors of the upper turntable motor side and the encoder side is realized in the same reference coordinate system, the error caused by different measurement bases is eliminated, and the accuracy and comparability of the detection results are improved; through data processing means such as the least square method, the measurement results are further optimized, and the various errors of the turntable shaft within a complete rotation cycle can be effectively detected; by setting a gear transmission shaft between the upper and lower turntables, the synchronous transmission of the upper turntable motor side and the encoder side is realized, providing a stable motion basis for the detection of the rotation axis error; using the mirror symmetry of the standard 45-degree splitting square mirror block, the optical path design is simplified, and the stability and reliability of the system are improved. The overall measurement optical path connection upper laser tracker turntable axis error detection method of the present application provides reliable technical support for the high-precision manufacturing and calibration of the laser tracker turntable, and makes necessary technical preparations for realizing the overall measurement optical path connection upper axis laser tracker turntable axis error compensation and improving the tracking accuracy and stability of the laser tracker.

[0164] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown in sequence as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least some of the steps in the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The order of execution of these sub-steps or stages is not necessarily sequential, but can be executed in rotation or alternation with other steps or at least a portion of the sub-steps or stages of other steps.

[0165] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0166] Although the present application has been disclosed above with reference to the embodiments, they are not intended to limit the present application. Anyone with ordinary knowledge in the technical field may make slight changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be determined by the scope of the appended patent application.

Claims

1. A method for detecting the rotation axis error of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection, characterized in that: The following steps are involved: Step S1: constructing a microscope using an objective lens, a cylindrical lens, a charge-coupled image sensor, a standard 45-degree beam splitting square mirror block, and a fluorescence excitation light source; Step S2: setting a microscope, fluorescent microspheres, a substrate, and a six-dimensional precision calibration stage to image the fluorescent microspheres on the charge-coupled image sensor; Step S3: causing the six-dimensional precision calibration stage to perform translational motion in two non-parallel directions to obtain three XY axis width ratios corresponding to three images of the fluorescent microsphere before and after the movement on the charge-coupled image sensor, and determining a posture vector of the six-dimensional precision calibration stage corresponding to the same three XY axis width ratios before and after the movement; Step S4: causing the six-dimensional precision calibration stage to move back and forth along the direction of the posture vector while ensuring that the fluorescent microspheres can be imaged on the charge-coupled image sensor, thereby obtaining a functional relationship between the ratio of the fluorescent microspheres' heights to the XY-axis widths at different longitudinal object planes, i.e., a longitudinal object plane height function; translating the six-dimensional precision calibration stage by an actual displacement value on each longitudinal object plane to determine a corresponding measured displacement value of the fluorescent microspheres imaged on the charge-coupled image sensor, and obtaining a microscope magnification function based on the actual displacement value and the measured displacement value; Step S5: fixing the first gear and the second gear to the first rotating shaft and the second rotating shaft of the upper turntable respectively, and fixing a bracket with a gear transmission shaft on one side to the table surface of the lower turntable; Step S6: fixing the microscope on a six-dimensional precision adjustment stage, fixing the substrate with fluorescent microspheres on the table of a micro-translation adjustment stage, and fixing the micro-translation adjustment stage on the upper turntable, the first rotation axis, the second rotation axis, and the lower turntable rotation axis in sequence; Step S7: fixing the micro-translation adjustment stage with the fluorescent microspheres and the substrate on the lower turntable shaft, starting the lower turntable motor, rotating the lower turntable shaft through a minimum step angle and then stopping, recording the microscope imaging of the fluorescent microspheres, determining the centroid coordinates and the XY axis width ratio in the charge-coupled image sensor imaging plane coordinates using a two-dimensional Gaussian function, determining the microscopic magnification corresponding to the longitudinal object plane height of the fluorescent microspheres based on the XY axis width ratio, and determining the spatial coordinate value of the fluorescent microspheres mapped to the charge-coupled image sensor imaging plane coordinates based on the centroid coordinates and the microscopic magnification; Step S8: constructing a first reference coordinate system based on the spatial coordinate values, determining the spatial linear equation of the rotation axis of the lower turntable in the first reference coordinate system, and obtaining the radial runout value of the lower turntable rotation axis within a complete rotation cycle; Step S9: Setting the rotation axis of the lower turntable to be stationary, recording the spatial coordinate values of the fluorescent microspheres in the first reference coordinate system at this time, constructing a motion coordinate system of the six-dimensional precision adjustment translation stage, determining a first vector value of the unit vector on the X-axis of the motion coordinate system in the first reference coordinate system, determining a first coordinate value of the origin of the motion coordinate system in the first reference coordinate system, rotating the six-dimensional precision adjustment translation stage around the X-axis of the motion coordinate system by a first angle, and rotating the unit vector in the first reference coordinate system around the first vector value by the first angle to obtain a second vector value; Step S10: Rotating the first reference coordinate system around the X-axis of the motion coordinate system by the first angle to obtain a measurement coordinate system of the microscope, determining the spatial coordinate values of the fluorescent microspheres in the measurement coordinate system, and obtaining the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment translation stage is rotated by the first angle; Step S11: Rotate the six-dimensional precision adjustment stage back to the starting position, determine the third vector value of the unit vector on the Y-axis of the motion coordinate system of the six-dimensional precision adjustment stage in the first reference coordinate system, rotate the six-dimensional precision adjustment stage around the Y-axis of the motion coordinate system by a second angle, obtain the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment stage is rotated by the second angle, and obtain the first vector value, the first coordinate value, and the third vector value using the least squares method; Step S12: Fixing the micro-translation adjustment stage with the fluorescent microspheres and the substrate to the first rotation axis of the upper turntable, starting the upper turntable motor to control the rotation of the first rotation axis, constructing a second reference coordinate system, determining the spatial linear equation of the rotation axis on the motor side of the upper turntable in the second reference coordinate system, and obtaining the axial and radial runout values within a complete rotation cycle; Step S13: Determine the yaw and pitch angles of the second reference coordinate system relative to the first reference coordinate system using the six-dimensional precision adjustment translation stage, convert the unit vector in the first reference coordinate system into the yaw and pitch angles, obtain the spatial coordinates of the fluorescent microspheres in the second reference coordinate system in the first reference coordinate system, and convert the spatial linear equation of the rotation axis of the upper turntable into the spatial linear equation in the first coordinate system; Step S14: Fix the micro translation adjustment table with fluorescent microspheres and substrate on the second rotating shaft of the upper turntable, start the lower turntable motor, rotate 180 degrees to symmetrically exchange the positions of the upper turntable encoder side and the upper turntable motor side, and obtain the axial and radial runout values within a complete rotation cycle, and determine the spatial linear equations of the lower turntable rotation axis and the upper turntable encoder side rotation axis in the first reference coordinate system, so as to realize the determination of the spatial linear equations of the lower turntable rotation axis, the upper turntable motor side rotation axis and the upper turntable encoder side rotation axis in the same reference coordinate system and the error detection within a complete rotation cycle.

2. The method for detecting the rotation axis error of the rotary table of the rotary axis laser tracker according to claim 1, characterized in that: The microscope is constructed using an objective lens, a cylindrical lens, a charge-coupled image sensor, a standard 45-degree beam splitter square mirror block, and a fluorescence excitation light source, including: A cylindrical lens is placed between the objective lens and the charge coupled image sensor, wherein the bottom surface of the cylindrical lens is parallel to the charge coupled image sensor, the edge where the semicircular cross section of the cylindrical lens intersects with the bottom surface of the cylindrical lens is parallel to the X-axis of the imaging surface of the charge coupled image sensor, and the normal vector of the imaging surface of the charge coupled image sensor is parallel to the imaging optical axis of the objective lens; a standard 45-degree beam splitting square mirror block is placed under the objective lens, wherein the standard 45-degree beam splitting square mirror block includes a beam splitting surface, the edge of the beam splitting surface is parallel to the X-axis of the imaging surface of the charge coupled image sensor, the fluorescent light beam passes through the beam splitting surface and enters the objective lens, and is received by the charge coupled image sensor after passing through the cylindrical lens, and a fluorescent excitation light source is placed on the side of the mirror surface that forms an angle of 45 degrees with the beam splitting surface; the objective lens, the charge coupled image sensor, the cylindrical lens, the standard 45-degree beam splitting square mirror block and the fluorescent excitation light source constitute a microscope; the coordinate value of the intersection of the imaging optical axis of the objective lens and the imaging surface of the charge coupled image sensor in its imaging surface plane coordinate system is ( x o , y o ), and the imaging optical axis of the objective lens passes through the center point of the splitting surface of the standard 45-degree splitting square mirror block, and the distance between the focal longitudinal object plane of the microscope and the center point of the splitting surface is D.

3. The method for detecting the rotation axis error of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: Setting a microscope, fluorescent microspheres, a substrate, and a six-dimensional precision calibration stage to image the fluorescent microspheres on the charge-coupled image sensor includes: A fluorescent microsphere is fixed on a substrate, and the substrate is then fixed parallel to a six-dimensional precision calibration translation stage; the six-dimensional precision calibration translation stage with the substrate is placed at the lower end of the beam incident surface at the bottom of a standard 45-degree beam splitting square mirror block under a microscope; after turning on the fluorescent excitation light source, the light source beam is reflected by the standard 45-degree beam splitting square mirror block and then irradiated onto the fluorescent microsphere, causing the fluorescent microsphere to emit fluorescence. After being transmitted through the standard 45-degree beam splitting square mirror block, the fluorescent microsphere is imaged on the charge-coupled image sensor.

4. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: The six-dimensional precision calibration stage is caused to perform translational motion in two non-parallel directions to obtain three XY axis width ratios corresponding to three images of the fluorescent microsphere before and after the movement on the charge coupled image sensor, and a posture vector of the six-dimensional precision calibration stage corresponding to the same three XY axis width ratios before and after the movement is determined, including: The six-dimensional precision calibration stage is caused to perform a translational motion in two non-parallel directions to obtain three XY-axis width ratios corresponding to three images of the fluorescent microsphere before and after the movement on the charge-coupled image sensor. If the three XY-axis width ratios are the same, the plane determined by the two movement directions is a longitudinal object plane of the fluorescence microscope. The pitch and yaw postures of the six-dimensional precision calibration stage are traversed with a minimum step size. The above-mentioned translational motion is performed in each posture case, and the corresponding three XY-axis width ratios are obtained. Then, a posture vector of the six-dimensional precision calibration stage corresponding to the same three XY-axis width ratios before and after the movement is determined.

5. The method for detecting the rotation axis error of the rotary table of the rotary axis laser tracker according to claim 1, wherein: The six-dimensional precision calibration stage is moved back and forth along the direction of the posture vector, and the fluorescent microspheres are ensured to be imaged on the charge-coupled image sensor, thereby obtaining a functional relationship between the ratios of the fluorescent microspheres at different longitudinal object plane heights and the XY axis widths, i.e., a longitudinal object plane height function. The six-dimensional precision calibration stage is translated by an actual displacement value on each longitudinal object plane to determine a corresponding measured displacement value of the fluorescent microspheres imaged on the charge-coupled image sensor. A microscopic magnification function is obtained based on the actual displacement value and the measured displacement value, including: The six-dimensional precision calibration stage is moved back and forth along the direction of the posture vector, and the fluorescent microspheres are ensured to be imaged on the charge-coupled image sensor, so as to obtain a functional relationship between the ratios of the fluorescent microspheres at different longitudinal object plane heights and the XY axis widths, i.e., a longitudinal object plane height function. The six-dimensional precision calibration stage is translated by an actual displacement value on each longitudinal object plane, and a measured displacement value of the fluorescent microspheres is obtained on the charge-coupled image sensor. The measured displacement value of the fluorescent microspheres is divided by the actual displacement value to obtain a microscopic magnification on each longitudinal object plane. The microscopic magnification function is determined according to different longitudinal object plane heights corresponding to different microscopic magnifications.

6. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: The first gear and the second gear are fixed to the first rotating shaft and the second rotating shaft of the upper turntable respectively, and a bracket with a gear transmission shaft on one side is fixed to the table surface of the lower turntable, including: The first gear and the second gear are respectively fixed on the first rotating shaft and the second rotating shaft of the upper turntable, and a bracket with a gear transmission shaft on one side is fixed on the table surface of the lower turntable. When the lower turntable rotates, it drives the upper turntable and the bracket to rotate. The bracket is fixed to the gear transmission shaft through a bearing, and the two ends of the gear transmission shaft are respectively engaged with the first gear and the second gear of the upper turntable. When the first rotating shaft of the upper turntable rotates, the rotational force is transmitted to the gear transmission shaft through the first gear, so that the gear transmission shaft rotates, and then drives the second gear to rotate, thereby rotating the second rotating shaft.

7. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: The microscope is fixed on a six-dimensional precision adjustment displacement stage, the substrate with fluorescent microspheres is fixed on the table of a micro translation adjustment stage, and the micro translation adjustment stage is fixed on the upper turntable, the first rotation axis, the second rotation axis and the lower turntable rotation axis in sequence, including: Fix the microscope on a six-dimensional precision adjustment displacement stage; fix the substrate with fluorescent microspheres on the table top of a micro-translation adjustment stage, and fine-tune the spatial position of the fluorescent microspheres through the micro-translation adjustment stage; fix the micro-translation adjustment stage on the first rotating shaft, the second rotating shaft and the rotating shaft of the lower turntable in sequence. Each time the micro-translation adjustment stage is fixed, the upper turntable or the lower turntable motor is started to rotate the corresponding rotating shaft one circle, ensuring that the fluorescent microspheres are imaged by the microscope during the rotation of the shaft one circle.

8. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: The micro-translation adjustment stage with fluorescent microspheres and a substrate is fixed on the lower turntable shaft, the lower turntable motor is started, the lower turntable shaft is rotated to a minimum step angle and then remains stationary, the imaging of the fluorescent microspheres by the microscope is recorded, the centroid coordinates and the XY axis width ratio in the imaging plane coordinates of the charge-coupled image sensor are determined by a two-dimensional Gaussian function, the microscopic magnification corresponding to the longitudinal object plane height of the fluorescent microsphere is determined based on the XY axis width ratio, and the spatial coordinate value of the fluorescent microsphere mapped to the imaging plane coordinates of the charge-coupled image sensor is determined based on the centroid coordinates and the microscopic magnification, including: Fixing a micro-translation adjustment stage with a fluorescent microsphere substrate on a lower turntable shaft, starting a lower turntable motor so that the lower turntable shaft rotates a minimum step angle and then remains stationary, recording the imaging of the fluorescent microsphere by a microscope, fitting the imaging light intensity using a two-dimensional Gaussian function to obtain the centroid coordinates and XY axis width ratio in the imaging plane coordinates of a charge-coupled image sensor, determining the value of the microscope magnification function corresponding to the longitudinal object plane height of the fluorescent microsphere at this time using the XY axis width ratio, i.e., the microscope magnification at this time, dividing the centroid coordinates by the microscope magnification to obtain the spatial coordinate value of the fluorescent microsphere mapped to the imaging plane coordinates of the charge-coupled image sensor; By analogy, after the lower turntable rotates one circle, a corresponding series of fluorescent microsphere spatial coordinate values are obtained, and the plane ellipse function is fitted to the series of fluorescent microsphere spatial coordinate values to obtain a plane mapping space trajectory, and the length values of the major and minor axes of the fitted ellipse are recorded at this time. The pitch posture and yaw posture of the six-dimensional precision adjustment displacement stage are traversed with the minimum step size, and a length value of the major and minor axes of the fitted ellipse is obtained for each posture. When the major axis and minor axis of the fitted ellipse corresponding to a certain posture are the minimum values of all the pitch postures and yaw postures traversed, that is, when the rotation axis is perpendicular to the imaging plane, the length of the spatial plane trajectory of the mapped image is the shortest, and at this time the rotation axis of the lower turntable is parallel to the imaging optical axis of the fluorescence microscope.

9. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: Constructing a first reference coordinate system based on the spatial coordinate values, determining the spatial linear equation of the rotation axis of the lower turntable in the first reference coordinate system, and obtaining the radial runout value of the lower turntable rotation axis within a complete rotation cycle, including: In the case where the rotation axis of the lower turntable is parallel to the imaging optical axis of the microscope, on the premise that the imaging light intensity of the fluorescent microspheres corresponding to all step rotations of the lower turntable and their charge-coupled image sensor imaging plane coordinates are obtained, the center of mass coordinates and the XY axis width ratio in the charge-coupled image sensor imaging plane coordinates are obtained by two-dimensional Gaussian fitting of the imaging light intensity, the corresponding longitudinal object plane height value and the microscope magnification are obtained by the XY axis width ratio, the center of mass coordinates are divided by the microscope magnification, and the spatial coordinate value of the fluorescent microsphere mapped to the charge-coupled image sensor imaging plane coordinate is obtained. Let the center coordinate obtained after the plane elliptical function fitting of the spatial coordinate value be ( x 拟 , y 拟 ), the origin of the coordinate system of the CCI imaging plane is translated to the coordinate of the intersection of the imaging optical axis and the CCI imaging plane ( x o , y o ), and then translate along the imaging optical axis to the longitudinal object plane of the focus. The corresponding coordinate system at this time is recorded as the first reference coordinate system X 基 Y 基 Z 基 , the first reference coordinate system is the measurement coordinate system of the microscope at this time; the spatial coordinate value of the fluorescent microspheres mapped to the imaging plane coordinate of the charge coupled image sensor is subtracted from the intersection coordinate ( x o , y o ), get the first reference coordinate system X 基 Y 基 Z 基 The XY coordinate value of the fluorescent microsphere in the middle, the obtained vertical object plane height value is the first reference coordinate system X 基 Y 基 Z 基 The Z-axis coordinate value in the first reference coordinate system X is obtained. 基 Y 基 Z 基 Pass ( x 拟 - x o , y 拟 - y o ,0) point and with (0,0,1) as the direction of the spatial straight line equation, that is, the rotation axis of the lower turntable; in the first reference coordinate system X 基 Y 基 Z 基 In the figure, all axial runout values within a complete rotation cycle of the lower turntable shaft are the difference between the Z-axis value of the fluorescent microsphere corresponding to each rotation step angle of the lower turntable shaft and the Z-axis value of the fluorescent microsphere when it is not rotated. The radial runout value within a complete rotation cycle of the lower turntable shaft is the difference between the distance from the XY-axis plane coordinate of the fluorescent microsphere corresponding to each rotation step angle of the lower turntable shaft to the origin and the distance from the coordinate point on the fitted plane elliptical function corresponding to the rotation step angle to the origin.

10. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: The method includes setting the lower turntable axis to be stationary, recording the spatial coordinate value of the fluorescent microsphere in the first reference coordinate system at this time, constructing a motion coordinate system of the six-dimensional precision adjustment translation stage, determining a first vector value of a unit vector on the X-axis of the motion coordinate system in the first reference coordinate system, determining a first coordinate value of the origin of the motion coordinate system in the first reference coordinate system, rotating the six-dimensional precision adjustment translation stage around the X-axis of the motion coordinate system by a first angle, and rotating the unit vector in the first reference coordinate system around the first vector value by the first angle to obtain a second vector value, including: Make sure the lower turntable axis is stationary and record the position of the fluorescent microspheres in the first reference coordinate system X. 基 Y 基 Z 基 The spatial coordinate values in ; Construct the motion coordinate system X of the six-dimensional precision adjustment translation stage 调 Y 调 Z 调 , assuming that the motion coordinate system X of the six-dimensional precision adjustment translation stage 调 Y 调 Z 调 The unit vector on the X axis in the first reference coordinate system X 基 Y 基 Z 基 The first vector value in is ( u X , u Y ,u Z ), the motion coordinate system X 调 Y 调 Z 调 The origin of the first reference coordinate system X 基 Y 基 Z 基 The first coordinate value in is ( o X , o Y ,o Z ), so that the six-dimensional precision adjustment translation stage moves around the motion coordinate system X 调 Y 调 Z 调 The X axis rotates a first angle, that is, in the motion coordinate system X 基 Y 基 Z 基 In around the first vector value ( u X , u Y ,u Z ) rotates the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in the equation are about the first vector value ( u X , u Y ,u Z ) rotate the first angle; and set the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in the first coordinate value ( o X , o Y ,o Z ) are subtracted, and the first rotation transformation matrix is multiplied on the right to obtain the unit vectors (1,0,0), (0,1,0) and (0,0,1) around the first vector value ( u X , u Y ,u Z ) After rotating the first angle in the first reference coordinate system X 基 Y 基 Z 基 The corresponding second vector value in the first rotation transformation matrix is expressed as: in, u X 、 u Y 、 u Z are the X-axis, Y-axis, and Z-axis values of the first vector value, θ is the first angle; The first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in are respectively related to the first coordinate value ( o X , o Y ,o Z ) and subtract it to get (1- o X , - o Y , - o Z )、(- o X , 1- o Y , - o Z )and(- o X , - o Y , 1- o Z ), and then right-multiply the first rotation transformation matrix to obtain the second vector value, and then respectively add the second vector value to the first coordinate value ( o X , o Y ,o Z ) are added together to obtain ( i x , i y , i z )、( j x , j y , j z )and( k x , k y , k z ); Compare the origin coordinate (0, 0, 0) with the first coordinate value ( o X , o Y ,o Z ) and then right-multiply it by the first rotation transformation matrix, and then add it to the first coordinate value ( o X , o Y ,o Z ) add up to get ( t x , t y , t z ), then in the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) are rotated around the first vector value ( u X , u Y ,u Z ) After rotating the first angle, in the first reference coordinate system X 基 Y 基 Z 基 The second vector values in are ( i x - t x , i y - t y , i z - t z )、( j x - t x , j y - t y , j z - t z )and( k x - t x , k y - t y , k z - t z ).

11. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: The first reference coordinate system is rotated about the X-axis of the motion coordinate system by the first angle to obtain a measurement coordinate system of the microscope, the spatial coordinate values of the fluorescent microspheres in the measurement coordinate system are determined, and the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment translation stage is rotated by the first angle is obtained, including: The six-dimensional precision adjustment stage moves around the coordinate system X 调 Y 调 Z 调 The X-axis rotates a first angle, driving the fluorescence microscope around the motion coordinate system X 调 Y 调 Z 调 The X axis rotates by the first angle, at this time, the first reference coordinate system X 基 Y 基 Z 基 Also around the motion coordinate system X 调 Y 调 Z 调 The X-axis is rotated by a first angle to obtain the measurement coordinate system X of the microscope θ Y θ Z θ ; With the first reference coordinate system X in step S8 基 Y 基 Z 基 The measurement coordinate system of the microscope is similar to the situation, and the measurement coordinate system X of the fluorescent microsphere in the microscope is obtained. θ Y θ Z θ The spatial coordinate values in ( x θ , y θ , z θ ), the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment stage is obtained, and the expression is as follows: in,( x θ , y θ , z θ ) is the measurement coordinate system X of the fluorescent microsphere in the microscope θ Y θ Z θ The spatial coordinate value in ; ( i x - t x , i y - t y , i z - t z )、( j x - t x , j y - t y , j z - t z )and( k x - t x , k y - t y , k z - t z ) are the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) are rotated around the first vector value ( u X , u Y ,u Z ) After rotating the first angle in the first reference coordinate system X 基 Y 基 Z 基 The second vector value in ; The X coordinate of the fluorescent microsphere in the first reference coordinate system is when the lower turntable axis is stationary. 基 Y 基 Z 基 The spatial coordinate values in .

12. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker for overall measurement optical path connection according to claim 11, characterized in that: The six-dimensional precision adjustment stage is rotated back to the starting posture, and the third vector value of the unit vector on the Y-axis of the motion coordinate system of the six-dimensional precision adjustment stage in the first reference coordinate system is determined. The six-dimensional precision adjustment stage is rotated around the Y-axis of the motion coordinate system by a second angle, and the spatial coordinate relationship of the fluorescent microspheres before and after the six-dimensional precision adjustment stage is rotated by the second angle is obtained. The first vector value, the first coordinate value, and the third vector value are obtained by the least squares method, including: The six-dimensional precision adjustment platform is rotated back to the starting posture of step S9. Assume that the motion coordinate system X of the six-dimensional precision adjustment platform is 调 Y 调 Z 调 The unit vector on the Y axis of the first reference coordinate system X 基 Y 基 Z 基 The third vector value in is ( v X , v Y ,v Z ), so that the six-dimensional precision adjustment translation stage moves around the motion coordinate system X 调 Y 调 Z 调 The Y axis of the six-dimensional precision adjustment platform is rotated by a second angle; similarly, a spatial coordinate relationship of the fluorescent microsphere before and after the rotation of the six-dimensional precision adjustment platform is obtained, which is similar to expression (II); six relationships about nine unknown quantities are obtained, namely, the first vector value ( u X , u Y ,u Z ), the first coordinate value ( o X , o Y ,o Z ) and the third vector value ( v X , v Y ,v Z Repeat steps S9 to S11, rotate more different first angles and second angles to obtain more relations than the number of nine unknowns, thereby building an overdetermined system of equations, and calculating the first vector value ( u X , u Y ,u Z ), the first coordinate value ( o X , o Y ,o Z ) and the third vector value ( v X , v Y , v Z ).

13. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: Fix the micro-translation adjustment stage with fluorescent microspheres and substrate on the first rotating shaft of the upper turntable, start the motor of the upper turntable to control the rotation of the first rotating shaft, construct a second reference coordinate system, determine the spatial linear equation of the rotation axis on the motor side of the upper turntable in the second reference coordinate system, and obtain the axial and radial runout values within a complete rotation cycle, including: Fix the micro-translation adjustment stage with the fluorescent microsphere substrate on the first rotating shaft of the upper turntable, start the upper turntable motor to control the rotation of the first rotating shaft, and the rest of the operations are the same as steps S7 and S8. At this time, the measurement coordinate system of the microscope is X' 基 Y' 基 Z' 基 , that is, the second reference coordinate system is X' 基 Y' 基 Z' 基 Because the imaging fluorescence of the fluorescent microspheres is transmitted to the side beam incident surface of the standard 45-degree beam splitting square mirror block, the image is formed. Due to the mirror effect of the beam splitting surface of the standard 45-degree beam splitting square mirror block, the symmetrical mirror image of the fluorescent microspheres is obtained in the second reference coordinate system X' 基 Y' 基 Z' 基 The spatial coordinate values in are uniformly expressed as ( x’ , y',z' According to the distance D between the longitudinal object plane of the microscope and the center point of the spectroscopic plane in step S1, the actual fluorescent microspheres are obtained in the second reference coordinate system X' 基 Y' 基 Z' 基 The spatial coordinate values in are ( x’ , y’ -D ,z’ +D), similar to step S8, in the second reference coordinate system X' 基 Y' 基 Z' 基 In the process, the spatial linear equation of the rotation axis of the upper turntable motor side and the axial and radial runout values within a complete rotation cycle are obtained.

14. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, wherein: The yaw angle and pitch angle of the second reference coordinate system relative to the first reference coordinate system are determined based on the six-dimensional precision adjustment translation stage, the unit vector in the first reference coordinate system is converted into the yaw angle and pitch angle, the spatial coordinate value of the fluorescent microsphere in the second reference coordinate system in the first reference coordinate system is obtained, and the spatial straight line equation of the rotation axis of the upper turntable is converted into the spatial straight line equation in the first coordinate system, including: Since the second reference coordinate system X' 基 Y' 基 Z' 基 It is determined by the principle that the length of the spatial plane trajectory of the image mapped when the rotation axis is perpendicular to the imaging plane is the shortest, so the second reference coordinate system X' 基 Y' 基 Z' 基 With the first reference coordinate system X 基 Y 基 Z 基 There is a posture difference, which is due to the fact that the first reference coordinate system X 基 Y 基 Z 基 The corresponding six-dimensional precision adjustment translation stage posture is based on the second reference coordinate system X' 基 Y' 基 Z' 基 The corresponding six-dimensional precision adjustment platform has a yaw angle and a pitch angle, which are determined by the six-dimensional precision adjustment platform. The first reference coordinate system X 基 Y 基 Z 基 deflection θ' and pitch δ' After the angle is changed to the second reference coordinate system X' 基 Y' 基 Z' 基 , the corresponding second rotation transformation matrix that needs to be right multiplied is: in, θ' is the deflection angle, δ' is the pitch angle, ( u X , u Y ,u Z ) is the motion coordinate system X of the six-dimensional precision adjustment translation stage 调 Y 调 Z 调 The unit vector on the X axis of the first reference coordinate system X 基 Y 基 Z 基 The first vector value in , ( v X , v Y ,v Z ) is the motion coordinate system X of the six-dimensional precision adjustment translation stage 调 Y 调 Z 调 The unit vector on the Y axis of the first reference coordinate system X 基 Y 基 Z 基 The third vector value in ; By the second rotation transformation matrix and the motion coordinate system X 调 Y 调 Z 调 The origin of the first reference coordinate system X 基 Y 基 Z 基 The first coordinate value in ( o X , o Y ,o Z ), similar to the operation in step S9, the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0), (0,0,1) and the origin (0,0,0) are converted to ( i' x , i' y , i' z )、( j' x , j' y , j' z )、( k' x , k' y , k' z )and( t' x , t' y , t' z ), thereby obtaining the first reference coordinate system X 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0) and (0,0,1) in θ' and pitch δ' After the angle, in the first reference coordinate system X 基 Y 基 Z 基 becomes ( i' x - t' x , i' y - t' y , i' z - t' z )、( j' x - t' x , j' y - t' y , j' z - t' z )and( k' x - t' x , k' y - t' y , k' z - t' z ), and the fluorescent microspheres are obtained in the second reference coordinate system X' 基 Y' 基 Z' 基 The spatial coordinates in x’ , y’ -D ,z’ +D) corresponds to the first reference coordinate system X 基 Y 基 Z 基 The spatial coordinate values in ( x’ 基 , y’ 基 , z’ 基 ), the expression is: ； Wherein, D represents the distance between the longitudinal object plane of the microscope and the center point of the splitting plane; the second reference coordinate system X' 基 Y' 基 Z' 基 The coordinates of any two points on the space straight line equation of the rotation axis of the upper turntable motor side are converted by expression (Ⅳ) to obtain their coordinates in the first reference coordinate system X 基 Y 基 Z 基 The coordinate values in the first reference coordinate system X are determined 基 Y 基 Z 基 The spatial straight line equation in , that is, the spatial straight line equation of the rotation axis of the lower turntable and the rotation axis of the upper turntable motor side is determined in the same coordinate system.

15. The method for detecting rotation axis errors of a rotary table of a rotary axis laser tracker with an integral measurement optical path connection according to claim 1, characterized in that: Fix the micro translation adjustment stage with fluorescent microspheres and substrate on the second rotation axis of the upper turntable, start the lower turntable motor, rotate 180 degrees so that the upper turntable encoder side and the upper turntable motor side are symmetrically interchanged, and obtain the axial and radial runout values within a complete rotation cycle. Determine the spatial linear equations of the lower turntable rotation axis and the upper turntable encoder side rotation axis in the first reference coordinate system, and achieve the determination of the spatial linear equations of the lower turntable rotation axis, the upper turntable motor side rotation axis, and the upper turntable encoder side rotation axis in the same reference coordinate system, as well as error detection within a complete rotation cycle, including: Fix the micro translation adjustment stage with the fluorescent microsphere substrate on the second rotation axis of the upper turntable, start the lower turntable motor, and rotate it 180 degrees so that the upper turntable encoder side and the upper turntable motor side are symmetrically exchanged. Similar to steps S12 and S13, the axial and radial runout values within a complete rotation cycle are obtained; in the first reference coordinate system X 基 Y 基 Z 基 The spatial straight line equations of the lower turntable rotation axis and the upper turntable encoder side rotation axis are determined, and the error detection of the lower turntable rotation axis, the upper turntable motor side rotation axis and the encoder side rotation axis within a complete rotation cycle is realized, and the lower turntable rotation axis, the upper turntable motor side rotation axis and the encoder side rotation axis are determined in the same first reference coordinate system X 基 Y 基 Z 基 The equation of the line in space.

16. A device for detecting the rotation axis error of a rotary table of a rotary axis laser tracker with an integral measurement optical path connected thereto, characterized in that: The method for detecting the rotation axis error of a rotary table of a rotary laser tracker for executing the overall measurement optical path connection according to any one of claims 1 to 15 comprises: a microscope, a fluorescent microsphere, a substrate, and a six-dimensional precision calibration displacement stage, wherein the microscope is located above the fluorescent microsphere, the fluorescent microsphere is fixed on the substrate, and the substrate is fixed on the six-dimensional precision calibration displacement stage.

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