Overall measurement light path connection upper rotating shaft type laser tracker turntable rotating shaft error detection device

Abstract

The utility model discloses an overall measurement light path joint upper rotating shaft type laser tracker turntable rotating shaft error detection device, which belongs to the laser tracking measurement field, and comprises a microscope, a fluorescent microsphere, a substrate and a six-dimensional precision calibration displacement platform, the microscope is arranged above the fluorescent microsphere, the fluorescent microsphere is fixed on the substrate, the six-dimensional precision calibration displacement platform is arranged on the substrate, and the microscope is arranged on the substrate. The substrate is fixed on the six-dimensional precise calibration displacement table in parallel, and the six-dimensional precise calibration displacement table is placed at the lower end of the microscope. According to the utility model, the error detection of the rotating shaft of the rotary table of the overall measurement light path connected with the upper rotating shaft type laser tracker realizes high-precision and omnibearing detection of the error of the rotating shaft of the rotary table of the overall measurement light path connected with the upper rotating shaft type laser tracker, and effectively improves the detection efficiency and accuracy through optimizing the measurement light path and a mechanical transmission structure; and reliable guarantee is provided for performance evaluation and quality control of the laser tracker turntable.

Description

Technical Field

[0001] This utility model relates to the field of laser tracking and measurement technology, and in particular to a device for detecting the rotation axis error of a rotating stage of a laser tracker with an integrated measurement optical path connection. Background Technology

[0002] Laser trackers are characterized by high speed, high precision, and a large measurement range, and are widely used in aerospace, automotive manufacturing, electronics industry, and large-scale metrology. Currently, many laser trackers on the market use the overall measurement optical path as the middle section of the upper turntable's shaft, connecting the shafts on the motor side and encoder side of the upper turntable, thereby achieving servo pitch rotation of the upper turntable.

[0003] The turntable of a laser tracker includes an upper pitch rotation turntable and a lower horizontal rotation turntable, which correspond to the pitch axis and the horizontal rotation axis, respectively. Ideally, the two rotation axes intersect perfectly perpendicularly in space (without distance deviation), and neither axis exhibits axial or radial runout during rotation. However, in reality, the two rotation axes are not perfectly perpendicular (90°), nor do they ideally intersect in space (there is distance deviation), and they also exhibit radial runout during rotation. These non-ideal errors affect the tracking accuracy and stability of the laser tracker. Therefore, it is necessary to detect and calibrate these errors related to the two rotation axes to provide the prerequisites for error compensation.

[0004] The detection of perpendicularity and distance deviation between the two axes of a laser tracker can be categorized into the determination of the spatial linear equations of the two axis axes. Therefore, axis error detection includes the determination of the spatial linear equations of the axis axes and the detection of axis diameter runout. Currently, separate detection devices for the perpendicularity and axis diameter runout of the two axes of a laser tracker are relatively common, but no articles or technical documents have been found that propose a device for determining the spatial linear equations of the axis axes in a single coordinate system and simultaneously detecting axis diameter runout. For a rotary table of a laser tracker with an integrated measurement optical path connection to an upper axis, since its upper axis is divided into a motor side and an encoder side, in addition to detecting the spatial linear equations of the lower rotary table axis and axis diameter runout, it is also necessary to detect the spatial linear equations of the axis axes and axis diameter runout of both parts of the upper rotary table. Currently, no articles or literature have been found that describe a device for determining the spatial linear equations of three axes and simultaneously detecting axis diameter runout for such a rotary table of a laser tracker with an integrated measurement optical path connection to an upper axis. Utility Model Content

[0005] This application aims to overcome the shortcomings of the prior art and provide an overall measurement optical path connection device for detecting the rotation axis error of a rotary laser tracker turntable.

[0006] To achieve the above objectives, this application provides an overall measurement optical path connection top-rotating laser tracker turntable rotation axis error detection device, 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, the substrate is fixed parallel to the six-dimensional precision calibration displacement stage, and the six-dimensional precision calibration displacement stage is placed at the lower end of the microscope.

[0007] Optionally, the microscope includes: an objective lens, a cylindrical lens, a charge-coupled image sensor (CCIS), a standard 45-degree beam-splitting square lens, and a fluorescence excitation source. The cylindrical lens is placed between the objective lens and the CCIS, with its base parallel to the CCIS. The edge where the semicircular cross-section of the cylindrical lens intersects the base of the cylindrical lens is parallel to the X-axis of the imaging plane of the CCIS. The standard 45-degree beam-splitting square lens is placed below the objective lens.

[0008] The standard 45-degree beam-splitting square mirror block includes: a beam-splitting surface, which 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 is parallel to the X-axis of the imaging surface of the charge-coupled image sensor;

[0009] The fluorescence excitation source is placed on the mirror side at a 45-degree angle to the beam-splitting surface; the imaging optical axis of the objective lens passes through the center point of the beam-splitting surface of the standard 45-degree beam-splitting square lens block.

[0010] Optionally, the objective lens includes an imaging optical axis, wherein the normal vector of the imaging surface of the charge-coupled image sensor is parallel to the imaging optical axis.

[0011] Optionally, the standard 45-degree beam-splitting square mirror block further includes: a bottom beam incident surface and a side beam incident surface, wherein the bottom beam incident surface is located at the bottom of the standard 45-degree beam-splitting square mirror block, and the side beam incident surface is located at the side of the standard 45-degree beam-splitting square mirror block.

[0012] Optionally, the microscope is a fluorescence microscope, and the spatial position of the microscope is fixed.

[0013] Optionally, the overall measurement optical path connection to the rotary axis laser tracker turntable axis error detection device further includes: an upper turntable, a lower turntable, a lower turntable axis, and a six-dimensional precision adjustment displacement stage, wherein the lower turntable axis is located above the lower turntable, the upper turntable is located above the lower turntable, and the six-dimensional precision adjustment displacement stage is located above the upper turntable.

[0014] Optionally, the overall measurement optical path connection to the rotary laser tracker turntable rotation axis error detection device further includes: a first gear, a second gear, a gear drive shaft, a first rotating shaft, a second rotating shaft, a bracket, a bearing, and a micro translation adjustment stage. The first gear is fixed to the first rotating shaft, and the second gear is fixed to the second rotating shaft. The first rotating shaft and the second rotating shaft are respectively fixed to both sides of the upper turntable. The gear drive shaft is disposed above the bracket, and the bracket is fixed to the table surface of the lower turntable. The micro translation adjustment stage is disposed on the bracket, and the bracket is fixed to the gear drive shaft via the bearing. The two ends of the gear drive shaft respectively mesh with the first gear and the second gear.

[0015] Optionally, the substrate with fluorescent microspheres is fixed to the stage of the micro translation adjustment stage.

[0016] Optionally, the overall measurement optical path is connected to the rotary laser tracker turntable shaft error detection device, and further includes: a motor-side rotation axis and an encoder-side rotation axis, wherein the first shaft and the first gear rotate around the motor-side rotation axis as the rotation center; and the second shaft and the second gear rotate around the encoder-side rotation axis as the rotation center.

[0017] Optionally, when the lower turntable rotates for imaging, the bottom beam incident surface of the standard 45-degree beam-splitting square mirror block receives fluorescence; when the upper turntable rotates for imaging, the side beam incident surface of the standard 45-degree beam-splitting square mirror block receives fluorescence.

[0018] In the above-mentioned technical solution of this utility model, by setting a fluorescent microscope with a fixed spatial position, combined with fluorescent microspheres fixed on a substrate, and a six-dimensional precision calibration displacement stage, precise imaging and positioning adjustment of the fluorescent microspheres can be achieved, providing a stable and accurate measurement benchmark for subsequent error detection. The special settings of components such as cylindrical lenses and standard 45-degree beam-splitting square mirror blocks in the microscope optimize the light propagation path, enabling accurate transmission of the fluorescent microsphere image to the charge-coupled image sensor, improving imaging quality and detection accuracy. Through the cooperation of structures such as the upper turntable, lower turntable, and gear transmission, as well as the design of the rotation axes on the motor side and encoder side, stable rotation and precise control of the turntable are achieved, which can simulate the actual working state of the turntable of a laser tracker.

[0019] In summary, this utility model's integrated measurement optical path connection to the rotary axis laser tracker turntable shaft error detection device achieves high-precision, all-around detection of the laser tracker turntable shaft error. By optimizing the measurement optical path and mechanical transmission structure, it effectively improves detection efficiency and accuracy, providing a reliable guarantee for the performance evaluation and quality control of the laser tracker turntable.

[0020] To make the above-mentioned features and advantages of the utility model more apparent and understandable, specific embodiments are described below, and detailed descriptions are provided in conjunction with the accompanying drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a structural diagram of the overall measurement optical path connection and the rotary axis error detection device of the rotary laser tracker provided in one embodiment of the present invention.

[0023] Figure 2 This is a structural diagram of the six-dimensional precision calibration displacement stage in the rotary axis error detection device of the rotary axis laser tracker provided in one embodiment of the present invention, which is connected to the overall measurement optical path.

[0024] Figure 3 This is a structural diagram of the overall measurement optical path connection and the rotary axis error detection device of the rotary laser tracker provided in another embodiment of the present invention.

[0025] In the figure: 1 Objective lens, 2 Cylindrical lens, 3 Charge-coupled image sensor, 4 Imaging optical axis, 5 Standard 45-degree beam-splitting square lens block, 6 Beam-splitting surface, 7 Fluorescent excitation source, 8 Microscope, 9 Fluorescent microsphere, 10 Substrate, 11 Six-dimensional precision calibration 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 axis, 18 First axis, 19 Second axis, 20 Lower turntable rotation axis, 21 Motor-side rotation axis, 22 Encoder-side rotation axis, 23 First gear, 24 Second gear, 25 Gear drive shaft, 26 Support, 27 Bearing, 28 Six-dimensional precision adjustment stage, 29 Miniature translation adjustment stage.

[0026] In the accompanying drawings, similar reference numerals refer to the same elements. Detailed Implementation

[0027] To make the objectives and technical solutions of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the described embodiments of this application without creative effort are within the scope of protection of this application.

[0028] In one embodiment, see Figure 1 and Figure 2 This application provides an overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device, including: microscope 8, fluorescent microsphere 9, substrate 10, and 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, the substrate 10 is fixed parallel to the six-dimensional precision calibration displacement stage 11, and the six-dimensional precision calibration displacement stage 11 is placed at the lower end of the microscope 8.

[0029] As an example, the fluorescent microsphere 9 can be a sub-millimeter-sized fluorescent microsphere.

[0030] As an example, the substrate 10 may be a planar substrate.

[0031] As an example, the microscope 8 includes: an objective lens 1, a cylindrical lens 2, a charge-coupled image sensor 3, a standard 45-degree beam-splitting square lens block 5, and a fluorescence excitation source 7. 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 plane of the charge-coupled image sensor 3. The standard 45-degree beam-splitting square lens block 5 is placed below the objective lens 1. The standard 45-degree beam-splitting square lens block 5 includes a beam-splitting surface 6. 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. The edges of the beam-splitting surface 6 are 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 beam can 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 source 7 is placed on the mirror side at a 45-degree angle to the beam-splitting surface 6. After the fluorescent excitation source 7 is turned on, the 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.

[0032] As an example, the coordinates of the intersection point of the objective lens imaging optical axis 4 and the imaging plane of the charge-coupled image sensor 3 in its imaging plane coordinate system are ( ). x o , y o ).

[0033] As an example, microscope 8 can be a fluorescence microscope, the microscope 8 has a fixed spatial position, and the microscope 8 has astigmatic imaging function.

[0034] As an example, the objective lens 1 may include: an imaging optical axis 4, wherein 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.

[0035] 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 on 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.

[0036] As an example, the microscope 8 may further include: a focal longitudinal object plane 14, which is an object plane perpendicular to the imaging optical axis 4 at the focal point, and the distance between the focal longitudinal object plane 14 and the center point of the beam splitting plane 6 is D.

[0037] As an example, a six-dimensional precision calibration stage 11 with substrate 10 can be placed below the beam incident surface 12 at the bottom of the standard 45-degree beam-splitting square mirror block 5 of the microscope 8. When the fluorescence excitation source 7 is turned on, the beam of the fluorescence excitation source 7 is reflected by the standard 45-degree beam-splitting square mirror block 5 and then irradiates the fluorescent microsphere 9, causing the fluorescent microsphere 9 to emit fluorescence. After being transmitted through the standard 45-degree beam-splitting square mirror block 5, the fluorescent microsphere 9 can be imaged on the charge-coupled image sensor 3.

[0038] As an example, the imaging centroid position of the fluorescent microsphere 9 can be obtained by fitting a two-dimensional Gaussian function to the imaging light intensity. The width values ​​of the imaging light intensity distribution along the X and Y axes of the imaging surface of the charge-coupled image sensor 3 can also be obtained, thus yielding the XY-axis width ratio of the fluorescent microsphere 9. The XY-axis width ratio includes the width ratio in the X-axis direction and the width ratio in the Y-axis direction. On different longitudinal object planes (imaging object planes perpendicular to the imaging optical axis), the XY-axis width ratio of the fluorescent microsphere 9 will differ due to the astigmatic imaging effect of the cylindrical lens 2.

[0039] As an example, when performing three-dimensional measurement calibration on microscope 8, the six-dimensional precision calibration stage 11 can be made to perform two non-parallel translational movements in two directions to obtain the three XY axis width ratios corresponding to the three images before and after the movement of the fluorescent microsphere 9 on the charge-coupled image sensor 3. If the three XY axis width ratios are the same, it indicates that the plane determined by the two translational movement directions is a longitudinal object plane of the fluorescence microscope. The pitch and yaw attitudes of the six-dimensional precision calibration stage 11 are traversed with the minimum step size. For each attitude, the above two non-parallel translational movements in the two directions are performed, and the corresponding three XY axis width ratios are obtained. From these, the attitude vector of the six-dimensional precision calibration stage 11 corresponding to the same three XY axis width ratios before and after the movement is determined. m , n , q ), which is the vector value in the coordinate system of the six-dimensional precision calibration displacement stage.

[0040] As an example, the attitude vector ( m , n , q ) is the normal vector of a longitudinal plane of the microscope, and also the vector of the imaging optical axis 4.

[0041] Furthermore, the six-dimensional precision calibration displacement stage 11 is aligned with the attitude vector ( m , n , q The fluorescent microsphere 9 moves back and forth in the direction of X and Y, ensuring that it can be imaged on the charge-coupled image sensor 3. This yields a functional relationship between the ratio of the fluorescent microsphere 9's height on different longitudinal surfaces (relative to the focal longitudinal surface) and its width along the X and Y axes, i.e., the longitudinal surface height function. f ( w ),in, w The XY axis width ratio variable of the fluorescent microsphere 9 is used. The six-dimensional precision calibration stage 11 is translated by an actual displacement value on each longitudinal surface, 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 magnification value on each longitudinal surface.

[0042] As an example, the magnification value varies depending on the longitudinal object height. Therefore, the magnification value can be a function related to the longitudinal object height or the XY-axis width ratio of the microsphere imaging. This magnification function is: N ( w ),in, w This represents 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 effect, the longitudinal object height function corresponding to the beam incident surface 13 on the side of the standard 45-degree beam-splitting square mirror block 5 can be obtained. f ( w ) and microscopic magnification function N ( w ).

[0043] In yet another embodiment, please refer to... Figure 3 The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device may further include: upper turntable 15, lower turntable 16, lower turntable rotation axis 17, and six-dimensional precision adjustment displacement stage 28, wherein the lower turntable rotation 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.

[0044] As an example, the microscope 8 can be fixed on a six-dimensional precision adjustment stage 28.

[0045] As an example, the overall measurement optical path connection to the rotary laser tracker turntable rotation axis error detection device may further 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 stage 29. 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 disposed above the bracket 26, the bracket 26 is fixed on the table surface of the lower turntable 16, and the micro translation adjustment stage 29 is disposed on the bracket 26. When the lower turntable 16 rotates, it can drive the upper turntable 15 to rotate, and also drive the bracket 26 to rotate. The bracket 26 is fixed to the gear drive shaft 25 through the bearing 27. The two ends of the gear drive 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 power can be transmitted to the gear drive shaft 25 through the first gear 23, causing the gear drive shaft 25 to rotate, thereby driving the second gear 24 to rotate, thus causing the second rotating shaft 19 to rotate.

[0046] As an example, the first gear 23 can be a motor-side gear, and the second gear 24 can be an encoder-side gear.

[0047] As an example, the first rotating shaft 18 can be a motor-side rotating shaft, and the second rotating shaft 19 can be an encoder-side rotating shaft.

[0048] As an example, the substrate 10 with fluorescent microspheres 9 can be fixed on the platform of the micro translation adjustment stage 29, which can finely adjust the spatial position of the fluorescent microspheres 9.

[0049] As an example, the miniature translation adjustment stage 29 can be fixed sequentially on the first rotating shaft 18, the second rotating shaft 19 of the upper turntable 15, and the rotating shaft 17 of the lower turntable.

[0050] As an example, after each micro-translation stage 29 is fixed, the corresponding rotating shaft is rotated one revolution by starting the upper or lower turntable motor, ensuring that the fluorescent microspheres 9 can be imaged by the microscope 8 during one revolution of the rotating shaft. The Gaussian fitting centroid coordinates of the image are variable in the plane coordinates of the imaging surface of the charge-coupled image sensor 3, that is, to ensure that the fluorescent microspheres 9 are not exactly on the axis of rotation, and to ensure that the microscope 8 with astigmatism imaging function is not touched by any object during the rotation of the upper turntable 15 and the lower turntable 16.

[0051] As an example, when the lower turntable rotates to 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 image, the side beam incident surface 13 of the standard 45-degree beam-splitting square mirror block 5 receives fluorescence.

[0052] For example, please refer to 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.

[0053] As an example, the microscope 8 that detects the fluorescent microspheres 9 will not be touched by any object during the rotation of the upper turntable 15 and the lower turntable 16.

[0054] In yet another embodiment, please refer to... Figure 3 The overall measurement optical path is connected to the rotary laser tracker turntable rotary axis error detection device, which may also include: a motor-side rotation axis 21 and an encoder-side rotation axis 22, wherein the first rotary axis 18 and the first gear 23 rotate around the motor-side rotation axis 21 as the rotation center; and the second rotary axis 19 and the second gear 24 rotate around the encoder-side rotation axis 22 as the rotation center.

[0055] For example, please refer to Figure 3 When using a microscope to detect errors on the turntable shaft, the miniature translation adjustment stage 29 with the fluorescent microsphere 9 substrate 10 is fixed again on the lower turntable shaft 17. The lower turntable motor is started, and the lower turntable shaft 17 is rotated by a minimum step angle and then stationary. Then, the image of the fluorescent microsphere 9 by the microscope 8 with astigmatic imaging function is recorded. The centroid coordinates and the XY axis width ratio in the imaging plane coordinates of the charge-coupled image sensor 3 are obtained by fitting the imaging light intensity with a two-dimensional Gaussian function. The microscopic magnification function corresponding to the longitudinal object height of the fluorescent microsphere 9 at this time is determined by the XY axis width ratio. N ( w The magnification factor of the microsphere is then used to divide the centroid coordinates by the magnification factor to obtain the spatial coordinates of the fluorescent microsphere 9 mapped onto the imaging plane coordinates of the charge-coupled image sensor 3.

[0056] Furthermore, the lower turntable 16 is rotated one revolution to obtain a series of corresponding spatial coordinate values ​​of the fluorescent microspheres 9. These spatial coordinate values ​​of the fluorescent microspheres 9 are then fitted with a planar elliptic function to obtain the planar mapped spatial trajectory drawn by the rotation axis through the fluorescent microspheres 9. The length values ​​of the major and minor axes of the fitted ellipse are recorded at this time. The pitch and yaw attitudes of the six-dimensional precision adjustment stage 28 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 attitude. When the major and minor axes of the fitted ellipse corresponding to a certain attitude are the minimum values ​​under all traversed attitudes, 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.

[0057] As an example, a planar elliptic function can be fitted using a general elliptic function whose major and minor axes are not parallel to the coordinate axes.

[0058] 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, given that the imaging light intensity of the fluorescent microsphere 9 and its imaging plane coordinates of the charge-coupled image sensor 3 are obtained for all the step rotations of the lower turntable, the centroid coordinates and the XY axis width ratio in the imaging plane coordinates of the charge-coupled image sensor 3 are obtained by fitting the imaging light intensity with a two-dimensional Gaussian. The corresponding longitudinal object height value and micromagnification are obtained from the XY axis width ratio. Dividing the centroid coordinates by the micromagnification yields the spatial coordinates of the fluorescent microsphere 9 mapped to the imaging plane coordinates of the charge-coupled image sensor 3. Let the center coordinates obtained after fitting these spatial coordinates with a plane 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 coordinates 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 At point 4, the image is then translated along the imaging optical axis 4 to the longitudinal object plane 14 of the focal point. The corresponding coordinate system at this point is denoted as the first reference coordinate system X. 基 Y 基 Z 基 The first reference coordinate system is the measurement coordinate system of microscope 8 at this time.

[0059] Furthermore, the spatial coordinates of the fluorescent microspheres 9 mapped to the imaging plane coordinates of the charge-coupled image sensor 3 are subtracted from the coordinates of the intersection point. x o , y o ), to obtain the first reference coordinate system X 基 Y 基 Z 基 The XY plane coordinates of the fluorescent microsphere 9 are obtained, and the resulting longitudinal height of the object surface is the first reference coordinate system X. 基 Y 基 Z 基 The Z-axis coordinate value is obtained. Thus, the X-axis coordinate system with the lower turntable rotation axis 20 as the first reference coordinate system can be obtained. 基 Y 基 Z 基 China x 拟 - x o , y 拟 - y o The equation of a straight line in space with the point (0, 0, 1) as the direction.

[0060] As an example, in the first reference coordinate system X 基 Y 基 Z 基 In the process, the axial runout values ​​of the lower turntable shaft 17 within one complete rotation cycle can be represented 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 at the point of no rotation. The radial runout values ​​of the lower turntable shaft 17 within one complete rotation cycle can be represented as the difference between the distance from the origin to the XY-axis plane coordinates of the fluorescent microsphere 9 corresponding to each rotation step angle of the lower turntable shaft 17 and the distance from the origin to the coordinate point on the fitted elliptic function corresponding to this rotation step angle.

[0061] Furthermore, ensure that the lower turntable shaft 17 remains stationary, and record the position of the fluorescent microsphere 9 in the first reference coordinate system X. 基 Y 基 Z 基 Spatial coordinates in Construct the motion coordinate system X of the six-dimensional precision-adjustable displacement stage 28. 调 Y 调 Z 调 Assuming the motion coordinate system X of the six-dimensional precision adjustment displacement stage 28 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 ), 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 ), causing the six-dimensional precision adjustment displacement stage 28 to rotate around the motion coordinate system X 调 Y 调 Z 调 Rotate the X-axis by a tiny first angle i That is, in the moving coordinate system X 基 Y 基 Z 基 The first vector value of the middle winding ( u X , uY ,u Z Rotate the first angle i 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 orbit around the first vector value ( u X , u Y ,u Z Rotate the first angle i .

[0062] Furthermore, 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 respectively associated with the first coordinate value ( o X , o Y ,o Z Subtract from each of the first and second transformations, and then multiply by the first rotation 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 the first angle i Then in the first reference coordinate system X 基 Y 基 Z 基 The corresponding second vector value.

[0063] As an example, the expression for the first rotation transformation matrix is:

[0064]

[0065] in, u X , u Y , u Z These are the X-axis, Y-axis, and Z-axis values ​​of the first vector value, respectively. i This is the first angle.

[0066] Furthermore, 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 respectively associated with the first coordinate value ( o X , o Y ,o Z Subtracting from each other, we get (1- o X , - o Y , - o Z ), (- o X , 1- o Y , - o Z )and(- o X , - o Y , 1- o Z Then, multiply the first rotation transformation matrix to the right to obtain the second vector value, and then multiply the second vector value by the first coordinate value ( ). o X , o Y ,o Z After adding them together, we get ( i x , i y , i z ), ( j x , j y , j z )and( k x , k y , k z ). The origin coordinates (0, 0, 0) are compared with the first coordinate value ( o X , o Y ,o Z Subtract from the first rotation transformation matrix, then multiply by the first coordinate value, and finally multiply by the first coordinate value. o X , o Y ,o ZAdding them together gives () t x , t y , t z 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) revolve around the first vector value ( u X , u Y ,u Z Rotate the first angle i Then in the first reference coordinate system X 基 Y 基 Z 基 The second vector values ​​in are respectively ( 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 ).

[0067] As an example, the six-dimensional precision adjustment displacement stage 28 rotates around the motion coordinate system X. 调 Y 调 Z 调 Rotate the X-axis by a tiny first angle i This causes the microscope 8 to also rotate around the X coordinate system. 调 Y 调 Z 调Rotate the X-axis by a tiny first angle i 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 Rotate the X-axis by a tiny first angle i The measurement coordinate system X of microscope 8 is obtained. θ Y θ Z θ .

[0068] Furthermore, the fluorescent microspheres 9 are measured in the X coordinate system of the microscope 8. θ Y θ Z θ The spatial coordinates in are ( x θ , y θ , z θ Furthermore, the spatial coordinate relationship of the fluorescent microsphere 9 before and after the rotation of the six-dimensional precision adjustment displacement stage 28 can be obtained, as expressed below:

[0069]

[0070] in,( x θ , y θ , z θ ( ) represents the measurement coordinates of fluorescent microspheres 9 in microscope 8, X. θ Y θ Z θ Spatial coordinates 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( kx - t x , k y - t y , k z - t z (x) represents the first reference coordinate system X. 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0), and (0,0,1) revolve around the first vector value ( u X , u Y ,u Z Rotate the first angle i Then in the first reference coordinate system X 基 Y 基 Z 基 The second vector value in; When the lower turntable shaft 17 is stationary, the fluorescent microsphere 9 is in the first reference coordinate system X. 基 Y 基 Z 基 Spatial coordinates in the data.

[0071] Furthermore, the six-dimensional precision adjustment stage 28 is rotated back to its initial position. Assume 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 in the first reference coordinate system X 基 Y 基 Z 基 The value of the third vector in is ( v X , v Y ,v Z ), causing the six-dimensional precision adjustment displacement stage 28 to rotate around the motion coordinate system X 调 Y 调 Z 调 Rotate the Y-axis by a tiny second angle d A spatial coordinate relationship of the fluorescent microsphere 9 before and after rotation of the six-dimensional precision-adjustable displacement stage 28 can be obtained, similar to expression (II). Thus, six relationships concerning the nine unknown quantities can be obtained, namely the first vector value ( u X , u Y ,u Z ), first coordinate value ( oX , o Y ,o Z ) and the third vector value ( v X , v Y ,v Z The six relations of ).

[0072] As an example, you can rotate to many different first angles. i Second angle d This allows us to obtain more relationships than nine unknowns, enabling us to construct an overdetermined system of equations. The first vector value can then be calculated using the least squares method. u X , u Y , u Z ), first coordinate value ( o X , o Y ,o Z ) and the third vector value ( v X , v Y ,v Z ).

[0073] Further, a miniature translation adjustment stage 29 with a fluorescent microsphere 9 substrate 10 is fixed on the first rotating shaft 18 of the upper turntable 15. The motor of the upper turntable 15 is started to control the rotation of the first rotating shaft 18. Given the imaging light intensity of the fluorescent microsphere 9 and its imaging plane coordinates corresponding to all step rotations of the upper turntable, the centroid coordinates and XY axis width ratio in the imaging plane coordinates of the charge-coupled image sensor 3 are obtained by fitting the imaging light intensity using a two-dimensional Gaussian method. The corresponding longitudinal object height value and micromagnification are obtained through the XY axis width ratio. The centroid coordinates are divided by the micromagnification to obtain the spatial coordinates of the fluorescent microsphere 9 mapped to the imaging plane coordinates of the charge-coupled image sensor 3. The origin of the coordinate system of the imaging plane of the charge-coupled image sensor 3 is translated to the intersection of the imaging optical axis 4 of the microscope and the imaging plane of the charge-coupled image sensor 3, and then translated along the imaging optical axis 4 to the longitudinal object plane 14 of the focal point. 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.

[0074] As an example, because the imaging fluorescence of the fluorescent microsphere 9 is transmitted to the beam incident surface 13 on the side of the standard 45-degree beam-splitting square mirror block 5 for imaging, and due to the mirroring effect of the beam-splitting surface 6 of the standard 45-degree beam-splitting square mirror block 5, a 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 the text are uniformly represented as ( x’ , y’, z’ Since the distance between the focal longitudinal object plane 14 of microscope 8 and the center point of the 45-degree beam splitter 6 is D, the actual fluorescent microsphere 9 can be obtained in the second reference coordinate system X'. 基 Y' 基 Z' 基 The spatial coordinates in are ( x’ , y’ -D ,z’ +D), in the second reference coordinate system X' 基 Y' 基 Z' 基 In this process, the spatial linear equation of the rotation axis 21 on the motor side of the upper turntable 15 and the axial and radial runout values ​​within a complete rotation cycle can be obtained.

[0075] As an example, due to the second reference coordinate system X' 基 Y' 基 Z' 基 It is also determined by the principle that the spatial plane trajectory of the image is the shortest when the rotation axis is perpendicular to the imaging plane, 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 attitude differences, which are due to the first reference coordinate system X. 基 Y 基 Z 基 The corresponding six-dimensional precision adjustment stage 28 attitude and the second reference coordinate system X' 基 Y' 基 Z' 基 The corresponding six-dimensional precision adjustment displacement stage 28 exhibits a yaw angle. I will (i.e., around the moving coordinate system X) 调 Y 调 Z 调 (X-axis rotation) and pitch angle d' (i.e., around the moving coordinate system X) 调 Y 调 Z 调(Y-axis rotation).

[0076] As an example, the yaw angle and pitch angle can be determined by the six-dimensional precision adjustment displacement stage 28, denoted as the first reference coordinate system X. 基 Y 基 Z 基 Bias I will and up and down d' After the angle is adjusted, it becomes the second reference coordinate system X' 基 Y' 基 Z' 基 The second rotation transformation matrix that needs to be multiplied on the right is:

[0077]

[0078] in, I will For the deflection angle, d' For pitch angle, ( u X , u Y ,u Z The X coordinate system of the six-dimensional precision adjustment displacement stage 28 is the motion coordinate system. 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 ( v X , v Y ,v Z The X coordinate system of the six-dimensional precision adjustment displacement stage 28 is the motion coordinate system. 调 Y 调 Z 调 The unit vector on the Y-axis in the first reference coordinate system X 基 Y 基 Z 基 The third vector value in the dataset.

[0079] As an example, all quantities in the second rotation transformation matrix are known. This is achieved through 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 ). 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 transformed into ( 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 Thus, the first reference coordinate system X can be obtained. 基 Y 基 Z 基 The unit vectors (1,0,0), (0,1,0), and (0,0,1) in the diagram deflect. I will and up and down d' After the angle, in the first reference coordinate system X 基 Y 基 Z 基 The middle becomes ( ) respectively 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 Thus, the fluorescent microsphere 9 can be obtained in the second reference coordinate system X'. 基 Y' 基 Z' 基 Spatial coordinates in ( x’ , y’ -D ,z’ +D) corresponds to the first reference coordinate system X 基 Y 基 Z 基 Spatial coordinates in ( x’ 基 , y’ 基 , z’ 基 The expression is:

[0080] .

[0081] As an example, the second reference coordinate system X' 基 Y' 基 Z' 基 The coordinates of any two points on the spatial straight line equation of the rotation axis 21 on the motor side of the upper turntable 15 can be obtained by transforming the coordinates of any two points in the first reference coordinate system X after transformation by expression (Ⅳ). 基 Y 基 Z 基 The coordinate values ​​in the first reference coordinate system X are used to determine the coordinates. 基 Y 基 Z 基 The spatial linear equations in the equations are used to determine the spatial linear equations of the lower turntable rotation axis 20 and the upper turntable motor side rotation axis 21 in the same coordinate system.

[0082] As an example, a miniature translation adjustment stage 29 with a fluorescent microsphere substrate 10 can be fixed on the second rotating shaft 19 of the upper turntable 15. The lower turntable motor is then started, rotating 180 degrees to symmetrically interchange the encoder side and motor side of the upper turntable 15, thus obtaining the axial and radial runout values ​​within a complete rotation cycle. In the first reference coordinate system X... 基 Y 基 Z 基 The spatial linear equations of the lower turntable rotation axis 20 and the encoder-side rotation axis 22 of the upper turntable 15 are determined to achieve 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, and to determine that the lower turntable rotation axis 20, the upper turntable 15 motor-side rotation axis 21, and the encoder-side rotation axis 22 are in the same first reference coordinate system X.基 Y 基 Z 基 The equation of a straight line in space.

[0083] In the aforementioned overall measurement optical path connection of the rotary laser tracker turntable shaft error detection device, astigmatism is introduced through a cylindrical lens to establish a functional relationship between the XY axis width ratio of the fluorescent microsphere imaging and the longitudinal object height. During the turntable shaft error detection process, by fixing the fluorescent microsphere substrate to the lower turntable shaft, the motor side of the upper turntable, and the encoder side shaft respectively, and combining multi-coordinate system transformation and spatial linear equation construction, the radial runout value, axial runout value, and other error parameters of each shaft can be comprehensively detected. By adjusting the rotation of the six-dimensional precision adjustment stage and coordinate system transformation, the detection of the rotation axis error of the upper turntable motor side and encoder side is realized under the same reference coordinate system, eliminating the error caused by different measurement references and improving the accuracy and comparability of the detection results. By setting a gear transmission shaft between the upper and lower turntables, synchronous transmission between the upper turntable motor side and encoder side is realized, providing a stable motion basis for shaft error detection. The mirror symmetry of the standard 45-degree beam-splitting square mirror block simplifies the optical path design and improves the stability and reliability of the system.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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.

[0085] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0086] Although this application has been disclosed above with reference to embodiments, it is not intended to limit this application. Anyone skilled in the art may make some modifications and refinements without departing from the spirit and scope of this application. Therefore, the scope of protection of this application shall be determined by the appended claims.

Claims

1. A device for detecting the rotation axis error of a rotary laser tracker turntable with an integrated measurement optical path connection, characterized in that, include: The system comprises a microscope, fluorescent microspheres, a substrate, and a six-dimensional precision calibration stage. The microscope is positioned above the fluorescent microspheres, the fluorescent microspheres are fixed to the substrate, the substrate is fixed parallel to the six-dimensional precision calibration stage, and the six-dimensional precision calibration stage is placed at the lower end of the microscope.

2. The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device according to claim 1, characterized in that, The microscope includes: an objective lens, a cylindrical lens, a charge-coupled image sensor (CCIS), a standard 45-degree beam-splitting square lens, and a fluorescence excitation source. The cylindrical lens is placed between the objective lens and the CCIS, with its base parallel to the CCIS. The edge where the semicircular cross-section of the cylindrical lens intersects the base of the cylindrical lens is parallel to the X-axis of the imaging plane of the CCIS. The standard 45-degree beam-splitting square lens is placed below the objective lens. The standard 45-degree beam-splitting square mirror block includes: a beam-splitting surface, which 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 is parallel to the X-axis of the imaging surface of the charge-coupled image sensor; The fluorescence excitation source is placed on the mirror side at a 45-degree angle to the beam-splitting surface; the imaging optical axis of the objective lens passes through the center point of the beam-splitting surface of the standard 45-degree beam-splitting square lens block.

3. The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device according to claim 2, characterized in that, The objective lens includes an imaging optical axis, wherein the normal vector of the imaging surface of the charge-coupled image sensor is parallel to the imaging optical axis.

4. The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device according to claim 2, characterized in that, The standard 45-degree beam-splitting square mirror block further includes: a bottom beam incident surface and a side beam incident surface, wherein the bottom beam incident surface is located at the bottom of the standard 45-degree beam-splitting square mirror block, and the side beam incident surface is located at the side of the standard 45-degree beam-splitting square mirror block.

5. The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device according to claim 2, characterized in that, The microscope is a fluorescence microscope, and its spatial position is fixed.

6. The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device according to claim 4, characterized in that, Also includes: The system includes an upper turntable, a lower turntable, a lower turntable shaft, and a six-dimensional precision adjustment displacement stage, wherein the lower turntable shaft is located above the lower turntable, the upper turntable is located above the lower turntable, and the six-dimensional precision adjustment displacement stage is located above the upper turntable.

7. The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device according to claim 6, characterized in that, Also includes: The system comprises a first gear, a second gear, a gear drive shaft, a first rotating shaft, a second rotating shaft, a bracket, a bearing, and a miniature translation adjustment platform. The first gear is fixed to the first rotating shaft, and the second gear is fixed to the second rotating shaft. The first and second rotating shafts are respectively fixed to opposite sides of the upper turntable. The gear drive shaft is positioned above the bracket, which is fixed to the surface of the lower turntable. The miniature translation adjustment platform is mounted on the bracket, and the bracket is fixed to the gear drive shaft via the bearing. Both ends of the gear drive shaft mesh with the first and second gears, respectively.

8. The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device according to claim 7, characterized in that, The substrate with fluorescent microspheres is fixed on the stage of the micro translation adjustment stage.

9. The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device according to claim 8, characterized in that, Also includes: The motor-side rotation axis and the encoder-side rotation axis, wherein the first rotating shaft and the first gear rotate around the motor-side rotation axis as the rotation center; The second shaft and the second gear rotate around the encoder-side rotation axis as the rotation center.

10. The overall measurement optical path connection upper rotating axis laser tracker turntable rotation axis error detection device according to claim 6, characterized in that, When the lower turntable rotates for imaging, the bottom beam incident surface of the standard 45-degree beam-splitting square mirror block receives fluorescence; when the upper turntable rotates for imaging, the side beam incident surface of the standard 45-degree beam-splitting square mirror block receives fluorescence.

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