A wide-range high-precision spatial angle measuring device and measuring method

Abstract

The application discloses a large-range high-precision spatial angle measuring device and a measuring method, and the measuring device comprises a autocollimator, a two-dimensional rotary table, an autocollimator adjusting base, an electronic level, a lifting and tilting adjusting system and a data acquisition and processing system. The autocollimator is used for measuring a small angle with high precision, and a device capable of being used for large-range high-precision spatial attitude angle measurement is developed. In the high-precision angle measurement, the autocollimator can be used to increase the angle measurement range, meet the angle measurement requirement of large or immovable pieces, and the angle measurement system can also be used for high-precision angle measurement of special-shaped pieces. The application can be widely applied to large-range high-precision attitude angle measurement, improve the accuracy of the measurement result, and meet various angle measurement requirements.

Description

Technical Field

[0001] This invention belongs to the field of optical metrology instruments, specifically relating to a large-range, high-precision spatial angle measuring device and method. Background Technology

[0002] Autocollimators have a wide range of applications, and most industrialized countries can independently develop and manufacture photoelectric autocollimators, such as the UK, Germany, Japan, and the US. Among them, the UK and Germany have the most mature technology in designing and manufacturing photoelectric autocollimators. Currently, foreign companies producing photoelectric autocollimators include Taylor / Hobson (UK), TRIOPTICS and MOLLER (Germany), and API (USA). my country's production of autocollimators began in the 1970s, and currently, the main units engaged in the research and development of this instrument include Changchun University of Technology and Tianjin Automer. A photoelectric autocollimator itself can only perform small-range precision angle measurements; it requires related accessories and functional modules to perform measurements on specific objects.

[0003] An autocollimator is a precision measuring instrument for small angle measurements. Used in conjunction with a precision turntable (autocollimation comparison angle measurement method), it can be used to measure small and lightweight angle gauges. When used with a plane mirror, it can be used to measure straightness, flatness, parallelism, perpendicularity, and other relative positional relationships. Optical angle measurement methods offer advantages such as non-contact measurement (this measurement is optical, requiring no direct contact with the measured part and thus preventing damage), high accuracy, and high sensitivity, making photoelectric autocollimators widely used in small angle measurements, flatness measurements, shaft angular wobble measurements, straightness measurements, and precision positioning measurements. However, the main drawbacks of this instrument are as follows:

[0004] (1) The measurement angle range is small. When the photoelectric autocollimator is used alone for angle detection, the measurement range is only ±1000″, which cannot meet the requirements of high-precision and large-range angle measurement.

[0005] (2) The volume and weight of the measurable parts are small. When combined with multi-tooth indexing table, goniometer, etc., to perform large-range angle measurement, the volume and weight of the measured parts are limited by the table surface and load-bearing range of multi-tooth indexing table, goniometer, etc.

[0006] (3) The measurement accuracy of large parts is low, and the main method used is the contact method to transition and the comparison method of non-contact measurement. During the contact method transition, the installation error of the measurement system (contact surface fit), alignment error, reading error and other factors have a great impact on the accuracy and repeatability of the measurement results, and high-precision measurement cannot be achieved.

[0007] The development of a wide-range, high-precision spatial angle measurement function for autocollimators allows for an increase in the measurement angle range of photoelectric autocollimators in high-precision angle measurement, meeting the angle measurement needs of large or immovable parts. At the same time, this angle measurement system can also perform high-precision angle measurement on irregularly shaped parts.

[0008] By utilizing a high-precision photoelectric autocollimator for measuring minute angles, a device has been developed for measuring large-scale, high-precision spatial attitude angles. Once completed, the system will significantly enhance spatial angle measurement capabilities and can be widely applied in aerospace, industrial control, and other fields. Summary of the Invention

[0009] This invention provides a large-scale, high-precision spatial angle measuring device and method, which can meet the in-situ high-precision angle measurement needs of large equipment and irregularly shaped parts, and can perform long-distance (20m) mirror splicing attitude angle measurement, playing a technical support role; it can be widely used in large-scale, high-precision attitude angle measurement, improving the accuracy of measurement results and fully meeting the social needs for surface angle measurement.

[0010] The technical solution adopted in this invention is as follows:

[0011] A wide-range, high-precision spatial angle measuring device, comprising an autocollimator, an autocollimator adjustment base, a two-dimensional turntable, an electronic level, a lifting and tilting adjustment system, a platform, and a data acquisition and processing system; the two-dimensional turntable includes an azimuth axis system and a pitch axis system.

[0012] The photoelectric autocollimator is mounted on the pitch axis of the two-dimensional turntable and combined with the turntable to form an autocollimator angle measurement system. The workpiece is fixedly mounted on the platform. The autocollimator angle measurement system is configured to measure the working surface of the workpiece at different positions I and II and obtain the corresponding pitch angle readings. By utilizing the rotation of the two-dimensional turntable and the cooperation of the electronic level and the tilt adjustment system, the rotation axis of the two-dimensional turntable is perpendicular to the ground when it is located at positions I and II. This ensures that the two measurements at positions I and II have a unified parallel reference axis system. The pitch angle readings are then taken from the two measurements at positions I and II and the difference between the two readings is taken as the measurement result of the pitch angle.

[0013] Furthermore, the measuring device also includes a prism system A and a prism system B for azimuth angle measurement. The prism system A and prism system B are respectively mounted on the platform via an adjustment support, which can adjust the working surfaces of the prism system A and prism system B to be parallel.

[0014] The present invention also provides a measurement method based on the aforementioned large-range, high-precision spatial angle measuring device, the method comprising:

[0015] When performing pitch angle measurement, the vertical orientation of the rotation axis of the two-dimensional turntable is determined, and the position of the two-dimensional turntable is changed multiple times so that the autocollimator angle measurement system measures the working surface of the workpiece at different positions. During the multiple position changes, the same vertical orientation of the rotation axis of the two-dimensional turntable is maintained, thereby achieving high-precision measurement of the pitch angle of large workpieces through different working surfaces.

[0016] When measuring azimuth, the adjustment support is adjusted so that the working surfaces of prism system A and prism system B are parallel. A reference is found by translation and rotation method as a transition reference, thereby connecting and measuring different working surfaces using optical path. High-precision angle measurement of the measured azimuth is obtained by direction determination and data processing.

[0017] The advantages of this invention compared to the prior art are:

[0018] (1) The fixed rotation axis method is adopted, which can ensure that the parallelism of the turntable rotation axis meets the requirements when the pitch angle is measured at different positions;

[0019] (2) An autocollimator angle measurement system was adopted to achieve high-precision in-situ angle measurement that traditional methods cannot solve;

[0020] (3) The translation and rotation method was adopted, and a unified reference datum (datum prism) was used for transition to measure the azimuth of large components at long distances (1m to 20m). Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a large-range, high-precision spatial angle measuring device according to the present invention;

[0022] Figure 2 A schematic diagram of the basic principle of a fixed axis of rotation;

[0023] Figure 3 This is a schematic diagram illustrating the principle of a self-collimator for measuring large-range, high-precision spatial pitch angles.

[0024] Figure 4 This is a schematic diagram illustrating the principle of a self-collimator for measuring spatial azimuth angles over a wide range with high precision. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1The diagram shows a large-range, high-precision spatial angle measuring device of the present invention. The measuring device includes an autocollimator 1, a two-dimensional turntable 3 (the two-dimensional turntable is the structure shown in the figure that includes the pitch axis system and the azimuth axis system), an autocollimator adjustment base 2, an electronic level 4, a platform 6, a lifting and tilting adjustment system 5, and a data acquisition and processing system.

[0027] As shown in the figure Figure 1 , Figure 3 As shown, the autocollimator 1 is mounted on the two-dimensional turntable 3 via the autocollimator adjustment base 2, forming an autocollimator angle measuring device. At this time, the electronic level 4 is fixed on the azimuth axis platform of the two-dimensional turntable 3. The workpiece is fixedly mounted on the platform. The two-dimensional turntable is rotated 360° along its azimuth axis, and the electronic level 4 measures and adjusts the lifting and tilting adjustment system 5 to ensure that the change in the electronic level 4 reading is within three numbers (II range). This ensures that the azimuth rotation axis of the two-dimensional turntable 3 is perpendicular to the ground in both positions I and II, guaranteeing a unified parallel reference axis for both measurements. Then, the autocollimator angle measuring system measures the working surface of the workpiece in positions I and II, and reads its pitch angle readings respectively. The difference between the readings in the two positions is taken as the measurement result. Measurable pitch angle range: -60° to +80°.

[0028] like Figure 4 As shown, when measuring azimuth angle, it is necessary to perform long-distance attitude angle splicing, adjust the working surfaces of two sets of reference prism systems A and B to be parallel, and connect and measure the different working surfaces using geometric optical paths through translation and rotation methods. High-precision angle measurement of the azimuth angle is obtained through direction determination and data processing. Measurable azimuth angle range: 0°~360° (internal and external angles can be measured).

[0029] Because the photoelectric autocollimator has a small angle measurement range of ±1000″, it cannot be used alone to detect large angles when performing high-precision automatic angle measurement. Therefore, by combining the photoelectric autocollimator 1 and the two-dimensional turntable 3 described in this invention (hereinafter referred to as: autocollimator angle measurement system), a system for high-precision, large-range angle measurement using an autocollimator is developed.

[0030] Traditional methods cannot accurately measure the angles of large workpieces. Traditional measuring parts are small in size and weight and can be placed directly on a turntable for measurement using an autocollimator. However, large workpieces are too large and heavy, far exceeding the turntable's capacity. Therefore, a new method is used to keep the large workpiece stationary and move the autocollimator to align it with the surface to be measured.

[0031] For large workpieces with long distances between the measured surfaces (1m to 20m), directly measuring their outer angles using an autocollimator angle measuring device (bubble leveling) can introduce measurement errors that can reach levels. Therefore, it is necessary to find the orientation of the two-dimensional turntable and maintain the same orientation of the turntable orientation axis during multiple position changes to achieve high-precision measurement of the pitch angle of large workpieces on different working surfaces. When measuring the azimuth angle, a translation and rotation method is used to find the reference, which serves as a transition reference. Different working surfaces are connected and measured using optical paths. High-precision angle measurement of the measured azimuth is obtained through direction determination and data processing.

[0032] The measurement method and the effects achieved by the measuring device of the present invention are as follows:

[0033] like Figure 3 and Figure 4 As shown, this invention utilizes a high-precision photoelectric autocollimator for measuring minute angles to develop a device for large-scale, high-precision spatial attitude angle measurement. It can meet the requirements for in-situ high-precision angle measurement of large equipment and irregularly shaped components, and can perform long-distance (20m) mirror splicing attitude angle measurement. It can be widely applied to large-scale, high-precision attitude angle measurement, improving the accuracy of measurement results. Once the system is completed, it will greatly enhance spatial angle measurement capabilities and can be widely used in aerospace, industrial control, and other fields.

[0034] The present invention can measure azimuth angle range: 0°~360° (can measure interior and exterior angles), with a measurement accuracy of 1″(σ); and can measure pitch angle range: -60°~+80°, with a measurement accuracy of 1″(σ). Specific implementation examples:

[0036] This invention employs a fixed rotation axis method, which ensures that the parallelism of the turntable's rotation axis meets requirements when measuring pitch angles at different positions. The basic principle of the fixed rotation axis is as follows:

[0037] like Figure 2 As shown, by using a plane mirror, precise angle measurement and diametrical measurement are performed by comparing the rotation stage from 0° to 180° based on the principle of optical autocollimation imaging. This allows for the accurate measurement of the rotation axis attitude angles (pitch angles β1 and β2) on the autocollimator, thereby quantifying and measuring the rotation axis attitude angles, thus finding the reference axis.

[0038] Direction determination and data processing: By adjusting the autocollimator base, the signs of β1 and β2 are opposite and their absolute values ​​are equal, i.e., β1 = -β2. At this time, the optical axis of the autocollimator is perpendicular to the azimuth axis.

[0039] When performing pitch angle measurements, see Figure 3With the autocollimator's optical axis perpendicular to the azimuth axis, adjust the lifting and tilting adjustment platform and rotate the azimuth axis 360° so that the change in the electronic level reading is within 3 numbers (II range), and the autocollimator's optical axis is basically parallel to the ground (at this point, the measurement requirements are met); during the measurement, (I) directly rotate the pitch axis and use the autocollimator to read the value, and take the difference Δβ1 between it and the initial value (pitch axis reading). Similarly, (II) measure the corresponding pitch angle Δβ2 on the other side, and take Δβ = Δβ2 - Δβ1 as the final result.

[0040] When performing azimuth measurements, see Figure 4 This requires long-distance attitude angle splicing, adjusting the parallelism of the working surfaces of two sets of reference prism systems A and B, and connecting and measuring the different working surfaces using geometric optical paths through translation and rotation. High-precision angle measurement of the measured azimuth angle is obtained through direction determination and data processing. Measurable pitch angle range: 0°~360° (internal and external angles can be measured).

[0041] The above-described embodiments are merely preferred embodiments of the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for measuring spatial angles over a wide range with high precision, characterized in that, The measurement method is based on a large-range, high-precision spatial angle measurement device, including an autocollimator (1), an autocollimator adjustment base (2), a two-dimensional turntable (3), an electronic level (4), a lifting and tilting adjustment system (5), a platform (6), and a data acquisition and processing system; the two-dimensional turntable (3) includes an azimuth axis system and a pitch axis system: The autocollimator (1) is installed on the pitch axis of the two-dimensional turntable (3) and combined with the two-dimensional turntable (3) to form an autocollimator angle measurement system; the workpiece is fixedly installed on the platform; the autocollimator angle measurement system is configured to measure the working surface of the workpiece at different positions I and II and obtain the corresponding pitch angle readings; by using the rotation of the two-dimensional turntable (3) and the cooperation of the electronic level (4) and the lifting and tilting adjustment system (5), the rotation axis of the two-dimensional turntable is perpendicular to the ground when it is located at positions I and II, thereby ensuring that the two measurements at positions I and II have a unified parallel reference axis system. Then, by taking two measurements at positions I and II and reading the pitch angle readings respectively, the difference between the readings at the two positions is taken as the measurement result of the pitch angle. The measuring device also includes a prism system A and a prism system B for azimuth angle measurement. The prism system A and the prism system B are respectively set on the platform (6) by an adjustment support. The adjustment support can adjust the working surfaces of the prism system A and the prism system B to be parallel. The method includes: When performing pitch angle measurement, the vertical orientation of the rotation axis of the two-dimensional turntable is determined, and the position of the two-dimensional turntable is changed multiple times so that the autocollimator angle measurement system measures the working surface of the workpiece at different positions. During the multiple position changes, the same vertical orientation of the rotation axis of the two-dimensional turntable is maintained, thereby achieving high-precision measurement of the pitch angle of large workpieces through different working surfaces. When measuring azimuth, the adjustment support is adjusted so that the working surfaces of prism system A and prism system B are parallel. A reference is found by translation and rotation method as a transition reference, thereby connecting and measuring different working surfaces using optical path. High-precision angle measurement of the measured azimuth is obtained by direction determination and data processing.

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