Measuring device and compensation method for measuring swing reference angle runout of rotary table

Abstract

The application relates to a measuring device and a compensation method for measuring the swing error of a rotary reference angle of a rotary table. The application is used to solve the problem that the rotary axis of a precision rotary table is invisible and the angular swing error is usually coupled when the coaxiality is measured. The measuring device comprises an ultra-precision rotary table, a CCD receiver, a laser emitter, a base and a position adjusting mechanism. The position adjusting mechanism and the ultra-precision rotary table are installed side by side on the base, the CCD receiver is installed on the position adjusting mechanism, the laser emitter is installed on the ultra-precision rotary table, and the laser emitter is located below the CCD receiver. The application belongs to the field of rotary table angular swing error measurement.

Description

Technical Field

[0001] This invention relates to a measuring device and a compensation method, belonging to the field of turntable angular pendulum error measurement. Background Technology

[0002] Currently, the industrial sector is undergoing a new round of industrial transformation. Countries around the world have launched industrial upgrading plans centered on the "Industrial Internet" and "Industry 4.0," and my country has also proposed the "Made in China 2025" development strategy, which includes intelligent production and assembly as an important component. Digital twins can improve the efficiency of equipment assembly and testing for enterprises through virtual simulation of production and assembly processes, providing support for solving management and upgrading issues throughout the entire product lifecycle.

[0003] Achieving intelligent coaxiality measurement, calibration, and error compensation for large rotating equipment (such as aero-engines and gas turbines) is a major challenge facing the development of my country's ultra-precision measurement field. Currently, coaxiality measurement of large rotating equipment in China is mainly based on ultra-precision coaxiality measuring instruments, including single-channel, dual-channel, four-channel, and five-channel instruments. These devices all rely on the core unit, the ultra-precision turntable, to establish a precise rotational reference. Since the machining and installation of the ultra-precision turntable introduces errors, angular pendulum error compensation is necessary to improve the accuracy of coaxiality measurement and calibration. Because the rotation axis of the precision turntable is invisible, angular pendulum errors are usually coupled during coaxiality measurement. Digital twins, an advanced technology combining virtual and real elements, can monitor and compensate for the angular pendulum error of the turntable's rotational reference by constructing a virtual axis. Summary of the Invention

[0004] To address the problem that the rotation axis of a precision turntable is not visible, and that the angular pendulum error is often coupled when measuring coaxiality, this invention proposes a measuring device and compensation method for measuring the rotation reference angular pendulum error of a turntable.

[0005] The technical solution adopted by the present invention to solve the above problems is as follows: The measuring device of the present invention includes an ultra-precision turntable, a CCD receiver, a laser emitter, a base, and a position adjustment mechanism; the position adjustment mechanism and the ultra-precision turntable are installed side by side on the base, the CCD receiver is installed on the position adjustment mechanism, and the laser emitter is installed on the ultra-precision turntable, with the laser emitter located below the CCD receiver.

[0006] Furthermore, the position adjustment mechanism includes a horizontal guide rail and a vertical guide rail; the lower end of the vertical guide rail is fixedly connected to the base, the horizontal guide rail is installed on the vertical guide rail, and the horizontal guide rail can move vertically up and down along the vertical guide rail, the CCD receiver is installed on the horizontal guide rail, and the CCD receiver can move linearly back and forth in the horizontal direction along the horizontal guide rail.

[0007] The specific steps of the compensation method described in this invention are as follows:

[0008] Step 1: Install the CCD receiver on the horizontal guide rail and obtain accurate height data relative to the plane of the ultra-precision turntable; place the laser emitter on the ultra-precision turntable, calibrate its position relative to the center of the ultra-precision turntable, and make it parallel to the CCD receiver.

[0009] Step 2: Rotate the ultra-precision turntable, and the laser emitter forms a trajectory on the panel of the CCD receiver;

[0010] Step 3: Fit the trajectory on the CCD receiver panel, find the center of the fitted circle, and connect it with the center position of the ultra-precision turntable to form the actual rotation axis of the turntable;

[0011] Step 4: Use augmented reality glasses to register the virtual turntable with the real turntable, and visualize the actual rotation axis of the turntable on the augmented reality glasses and computer screen;

[0012] Step 5: Based on the fitting of the actual rotation axis and theoretical rotation axis of the turntable using the ultra-precision turntable measurement reference digital twin system, the angular pendulum error is solved, and the angular pendulum error is compensated based on the data.

[0013] Furthermore, the specific steps in step five for solving the angular pendulum error by fitting the actual rotation axis and the theoretical rotation axis of the turntable based on the ultra-precision turntable measurement rotary reference digital twin system are as follows:

[0014] The trajectory of the CCD receiver panel is fitted using the least squares method: g(x,y)=f((x1,y1),(x2,y2),…,(x n ,y n ), where (x1,y1), (x2,y2)... represent the relative coordinates of the sampling points, n represents the total number of sampling points, and the center of the fitted circle (x1,y1), (x2,y2)... is obtained. c ,y c The relative height of the trajectory is the height of the CCD receiver panel relative to the turntable plane, denoted as h. Then the rotation axis vector relative to the center of the turntable is (x... c ,y c ,h), the angular pendulum error Δθ=arctan(sqrt(x 2 c +y 2 c ) / h), sqrt() means to take the square root.

[0015] The beneficial effects of this invention are as follows: Based on digital twin technology, this invention visualizes the virtual rotation axis of an ultra-precision turntable. By solving the angle between the virtual axis and the ideal rotation axis, the angular pendulum error is obtained. This method can monitor and compensate for the angular pendulum error in real time, realize the visualization of the virtual axis, and ensure the precise measurement of the angular pendulum error of the ultra-precision turntable in a large coaxiality measuring device. It solves the problem that traditional measurements using the rotation axis as a reference only have a conceptual expression, and through the visualization and adjustment of the rotation axis, measurement compensation can be achieved virtually, reducing the complexity caused by repeated adjustments during the measurement process. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the measuring device described in this invention;

[0017] Figure 2 This is a top view of an ultra-precision turntable;

[0018] Figure 3 This is a schematic diagram of the error of the ultra-precision turntable angular pendulum;

[0019] Figure 4 This is a schematic diagram of measuring the angle swing error of a precision turntable based on a laser emitter and CCD receiver panel.

[0020] Figure 5 It is the laser rotation trajectory on the CCD receiver panel;

[0021] Figure 1 1-Theoretical rotation axis of the turntable, 2-Actual rotation axis of the turntable, 3-Ultra-precision turntable, 4-CCD receiver, 5-Measuring optical path, 6-Laser emitter, 7-Horizontal guide rail, 8-Vertical guide rail, 9-Base, 10-Augmented reality glasses, 11-Computer display screen, 12-Virtual axis visualization;

[0022] Figure 3 1 - Ideal axis of rotation; 2 - Actual axis of rotation with an angular pendulum error of Δθ; 3 - Actual axis of rotation with an angular pendulum error of Δθ.

[0023] Figure 4 1-Ideal rotation axis, 2-Actual rotation axis, 3-CCD receiver panel, 4-Measuring optical path, 5-Laser generator, 6-Precision turntable;

[0024] Figure 5 1-CCD receiver panel, 2- Measurement optical path, the rotational trajectory formed on the CCD receiver panel, 3- Fitting circle center. Detailed Implementation

[0025] Specific implementation method one: Combining Figures 1 to 5This embodiment describes a measuring device for measuring the error of a rotary reference angle pendulum using a turntable. The device includes an ultra-precision turntable 3, a CCD receiver 4, a laser emitter 6, a base 9, and a position adjustment mechanism. The position adjustment mechanism and the ultra-precision turntable 3 are mounted side-by-side on the base 9. The CCD receiver 4 is mounted on the position adjustment mechanism, and the laser emitter 6 is mounted on the ultra-precision turntable 3, with the laser emitter 6 located below the CCD receiver 4.

[0026] When the ultra-precision turntable 3 is not placed parallel, angular swing error will occur during rotation. A laser generator 6 is installed on the ultra-precision turntable 3, and the position of the laser generator 6 on the ultra-precision turntable 3 is determined by calibration. The panel of the CCD receiver 4 is placed above the ultra-precision turntable 3 via horizontal guide rail 7 and vertical guide rail 8. The rotation of the ultra-precision turntable 3 drives the laser 6 to rotate, thus leaving a rotational motion trajectory on the panel of the CCD receiver 4. The line connecting the center of the fitted rotational motion trajectory on the panel of the CCD receiver 4 and the rotation center of the ultra-precision turntable 3 is the rotation axis of the turntable. The augmented reality glasses 10 perform virtual-real registration between the virtual turntable and the real turntable, and display the fitted virtual rotation axis in augmented reality. The angle between the virtual rotation axis and the ideal rotation axis is the angular swing error.

[0027] The virtual-real registration method adopts the point cloud registration method. By iteratively calculating the Euclidean distance between the environmental point cloud collected by AR glasses and the point cloud of the turntable virtual model, the optimal rotation and offset matrix is ​​obtained, thus realizing the virtual-real registration of the turntable.

[0028] Specific Implementation Method Two: Combining Figures 1 to 5 This embodiment describes a measuring device for measuring the error of a rotary reference angle pendulum on a turntable. The position adjustment mechanism includes a horizontal guide rail 7 and a vertical guide rail 8. The lower end of the vertical guide rail 8 is fixedly connected to the base 9. The horizontal guide rail 7 is mounted on the vertical guide rail 8 and can move linearly up and down along the vertical guide rail 8. The CCD receiver 4 is mounted on the horizontal guide rail 7 and can reciprocate linearly along the horizontal guide rail 7 in the horizontal direction.

[0029] Specific implementation method three: Combining Figures 1 to 5 This embodiment describes a method for compensating for the error of the rotary reference angle pendulum in turntable measurement, implemented through the following steps:

[0030] Step 1: Install the CCD receiver 4 on the horizontal guide rail 7 and obtain accurate height data relative to the plane of the ultra-precision turntable 3; place the laser emitter 6 on the ultra-precision turntable 3, calibrate its position relative to the center of the ultra-precision turntable 3, and make it parallel to the CCD receiver 4.

[0031] Step 2: Rotate the ultra-precision turntable 3, and the laser emitter 6 forms a trajectory on the panel of the CCD receiver 4;

[0032] Step 3: Fit the trajectory on the CCD receiver 4 panel, find the center of the fitted circle, and connect it with the center position of the ultra-precision turntable 3 to form the actual rotation axis 2 of the turntable;

[0033] Step 4: Use augmented reality glasses 10 to register the virtual turntable with the real turntable, and visualize the actual rotation axis 2 of the turntable on the augmented reality glasses 10 and the computer display screen 11;

[0034] Step 5: Based on the fitting of the actual rotation axis 2 and theoretical rotation axis 1 of the rotation reference digital twin system of the ultra-precision turntable 3, the angular pendulum error is solved, and the angular pendulum error is compensated based on the data.

[0035] Specific implementation method four: Combination Figures 1 to 5 This embodiment describes the specific steps in step five of the compensation method for measuring the rotational reference angular pendulum error using a turntable. These steps involve fitting the actual rotational axis 2 and the theoretical rotational axis 1 of the turntable based on the ultra-precision turntable 3's digital twin system for measuring the rotational reference to solve for the angular pendulum error.

[0036] The trajectory of the CCD receiver panel is fitted using the least squares method: g(x,y)=f((x1,y1),(x2,y2),…,(x n ,y n ), where (x1,y1), (x2,y2)... represent the relative coordinates of the sampling points, n represents the total number of sampling points, and the center of the fitted circle (x1,y1), (x2,y2)... is obtained. c ,y c The relative height of the trajectory is the height of the CCD receiver panel relative to the turntable plane, denoted as h. Then the rotation axis vector relative to the center of the turntable is (x... c ,y c ,h), the angular pendulum error Δθ=arctan(sqrt(x 2 c +y 2 c ) / h), sqrt() means to take the square root.

[0037] Working principle

[0038] This invention addresses the angular pendulum error compensation of an ultra-precision turntable 3. It utilizes digital twin technology to visualize the virtual axis of the ultra-precision turntable 3 and separately compensate for the angular pendulum error. The main method involves placing a laser emitter on the ultra-precision turntable 3 and simultaneously placing a CCD receiver 4 panel above the turntable in the vertical direction. A measurement optical path is established using the laser emitter 6 and the CCD receiver 4 panel. As the turntable rotates, the CCD receiver 4 panel receives the optical path data and uses augmented reality glasses to construct a virtual rotation axis. This virtual rotation axis can be observed in real-time on both the computer display screen 11 and the augmented reality glasses 10, achieving a digital twin of the turntable measurement system that combines virtual and real elements. This invention can be used for real-time analysis of the angular pendulum error of an ultra-precision turntable and for angular pendulum error compensation based on the height of different measurement sections.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent substitutions, and improvements made to the above embodiments without departing from the scope of the present invention, based on the technical essence of the present invention and within the spirit and principles of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A method for compensating for the error of the rotary reference angle pendulum used in turntable measurement, characterized in that: The compensation method is based on a measuring device for measuring the rotation reference angle error of the turntable. The measuring device includes an ultra-precision turntable (3), a CCD receiver (4), a laser emitter (6), a base (9), and a position adjustment mechanism. The position adjustment mechanism and the ultra-precision turntable (3) are mounted side by side on the base (9), the CCD receiver (4) is mounted on the position adjustment mechanism, and the laser emitter (6) is mounted on the ultra-precision turntable (3), with the laser emitter (6) located below the CCD receiver (4). The position adjustment mechanism includes a horizontal guide rail (7) and a vertical guide rail (8); the lower end of the vertical guide rail (8) is fixedly connected to the base (9), the horizontal guide rail (7) is installed on the vertical guide rail (8), and the horizontal guide rail (7) can move vertically up and down along the vertical guide rail (8), the CCD receiver (4) is installed on the horizontal guide rail (7), and the CCD receiver (4) can move linearly back and forth in the horizontal direction along the horizontal guide rail (7); The compensation method for the rotary reference angle pendulum error in turntable measurement is achieved through the following steps: Step 1: Install the CCD receiver (4) on the horizontal guide rail (7) and obtain accurate height data relative to the plane of the ultra-precision turntable (3); place the laser emitter (6) on the ultra-precision turntable (3), mark the position relative to the center of the ultra-precision turntable (3), and make it parallel to the CCD receiver (4); Step 2: Rotate the ultra-precision turntable (3) so that the laser emitter (6) forms a trajectory on the panel of the CCD receiver (4); Step 3: Fit the trajectory on the CCD receiver (4) panel, find the fitting center, and connect it with the center position of the ultra-precision turntable (3) to form the actual rotation axis (2) of the turntable. Step 4: Use augmented reality glasses (10) to register the virtual turntable with the real turntable, and visualize the actual rotation axis (2) of the turntable on the augmented reality glasses (10) and the computer screen (11); Step 5: Based on the ultra-precision turntable (3), measure the actual rotation axis (2) and theoretical rotation axis (1) of the fitted turntable of the rotation reference digital twin system to solve the angular pendulum error, and perform angular pendulum error compensation based on the data; The specific steps for solving the angular pendulum error based on the fitting of the actual rotation axis (2) and the theoretical rotation axis (1) of the rotation reference digital twin system of the ultra-precision turntable (3) are as follows: The trajectory of the CCD receiver panel was fitted using the least squares method. ,in( x 1, y 1) ( x 2, y 2) ... represents the relative coordinates of the sampling point. n This represents the total number of sampling points and obtains the center of the fitted circle. x c , y c The relative height of the trajectory is the height of the CCD receiver panel relative to the turntable plane, expressed as... h Then the vector of the rotation axis relative to the center position of the turntable is ( x c , y c , h ), the angular pendulum error Δθ = arctan(sqrt( x 2 c + y 2 c ) / h), sqrt() means to take the square root.

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