Device and method for automatically detecting measurement precision of angular position of rotary table

Abstract

The invention relates to an inertial platform testing device and method, in particular to an automatic detection device and method for rotary table angular position measurement precision, and solves the technical problems that the rotation angle precision of a measured shaft of a rotary table or a shaft angle encoder is difficult to quickly and accurately measure and the tower difference is difficult to automatically adjust in the prior art. The invention discloses an automatic detection device for the measurement precision of an angular position of a rotary table. The automatic detection device comprises a synchronous sampling unit, a processing unit, an autocollimator, a tool shaft, a right 23-surface prism and an electric two-dimensional adjusting mechanism, the synchronous sampling unit is respectively in communication connection with the to-be-tested turntable, the processing unit and the autocollimator; the processing unit is used for adjusting the alpha axis and the beta axis according to the rotation angle of the to-be-measured rotary table and the rotation angle of the right 23-face prism, so that the tower difference between the rotation axis of the right 23-face prism and the rotation axis of the to-be-measured rotary table is minimum. According to the detection method, the detection of the one-time angle measurement precision of the to-be-detected rotary table can be automatically detected, and the working efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to an inertial platform testing device and method, and in particular to a turntable angular position measurement accuracy automatic detection device and method. Background Art

[0002] The turntable is an advanced device equipped with complex optoelectronic payloads. It is widely used in aerospace testing and angle measurement, and provides high-precision angular position measurement information and angular position positioning for the various payloads it carries. Therefore, the angular position measurement accuracy index is particularly important as a core indicator for turntable products before leaving the factory or during regular calibration, and is considered a must-check item. At present, the angular position measurement accuracy of the turntable is generally tested in accordance with the methods specified in GJB1801 "Main Performance Test Methods for Inertial Technology Test Equipment" or JJF1210 "Low-Speed ​​Turntable Calibration Specifications" during factory inspection of finished products or third-party calibration. The above methods have the following defects and shortcomings:

[0003] 1. All operations are manual, which is labor-intensive and prone to errors;

[0004] 2. Error-free calibration method and calibration link, measurement accuracy is too dependent on operator experience and has poor universality;

[0005] 3. Only static testing can be performed, and dynamic angle measurement accuracy cannot be tested and evaluated.

[0006] There are two existing methods for dynamic accuracy detection of the shaft angle encoder of a turntable: first, a higher accuracy encoder, such as a 29-bit Heidenhain encoder, is coaxially installed on the shaft angle encoder to be measured, and then a motor is used to drive the two encoders to rotate synchronously, and the higher accuracy encoder is used as the true value to detect the encoder to be measured; second, a dynamic detection device based on a regular 23-faceted prism and an autocollimator; the regular 23-faceted prism is coaxially connected to the shaft angle encoder to be measured, and after the motor drives it to rotate continuously, the regular 23-faceted prism and the autocollimator are used to detect the true angle of rotation of the shaft angle encoder or the turntable to be measured in real time, and then the true angle of the measured axis is compared with its rotation angle for detection.

[0007] However, the above two methods have the following defects: they do not mention the adjustment device and adjustment method of the pyramidal error (the spatial angle between the rotating axis of the standard test material and the rotating axis of the measured axis) between the standard test material (high-precision shaft angle encoder or regular 23-faceted prism) and the measured axis, which has a great influence on high-precision detection; in addition, the first method uses a higher-precision angle measurement unit for comparison detection, which brings the problem of where the dynamic angle measurement accuracy of the higher-precision angle measurement unit comes from. Generally, only the static angle measurement accuracy is tested at the factory, and its maximum working angular velocity is noted, and there is no indicator of dynamic angle measurement accuracy. Therefore, standard traceability becomes a problem and falls into an endless loop; the realization of dynamic angle measurement in the second method is highly dependent on the high sampling rate of the autocollimator. The higher the rotation speed of the measured axis, the higher the sampling rate required by the autocollimator. To achieve high-precision synchronous acquisition in the rotating state, the sampling rate of the autocollimator is generally at least 1kHz, which cannot be achieved by the existing autocollimator unless the test resolution is reduced or the rotation speed is reduced, but this will undoubtedly reduce the detection accuracy and timeliness of the detection. Summary of the invention

[0008] The purpose of the present invention is to solve the technical problem that it is difficult to quickly and accurately measure the rotation angle accuracy of the measured shaft of a turntable or shaft angle encoder and automatically adjust the pyramidal error in the prior art, and to provide a turntable angular position measurement accuracy automatic detection device and detection method.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] An automatic detection device for measuring the angular position accuracy of a turntable, which is special in that it includes a synchronous sampling unit, a processing unit, an autocollimator and a tooling axis, a regular 23-face prism, and an electric two-dimensional adjustment mechanism;

[0011] The regular 23-face prism is sleeved on the tooling axis, and its working surface is arranged opposite to the autocollimator;

[0012] The inner center of the electric two-dimensional adjustment mechanism is located in the same horizontal plane and is provided with mutually perpendicular α-axis and β-axis, which are used to adjust the rotation angle of the electric two-dimensional adjustment mechanism along the α-axis and the β-axis respectively; the upper surface center of the electric two-dimensional adjustment mechanism is vertically fixedly connected to the tooling axis, and the lower surface is coaxially fixedly connected to the upper surface of the turntable to be measured; the α-axis and the β-axis are respectively connected to the processing unit for communication;

[0013] The synchronous sampling unit is respectively connected to the turntable to be measured, the processing unit and the autocollimator for communication; the autocollimator is used to collect the rotation angle of the regular 23-sided prism when receiving the trigger signal sent by the synchronous sampling unit; the synchronous sampling unit is used to collect the rotation angle of the turntable to be measured, and send a trigger signal to the autocollimator when the turntable to be measured rotates to the working angle of the regular 23-sided prism, and package the rotation angle of the turntable to be measured and the rotation angle of the regular 23-sided prism collected by the autocollimator and send them to the processing unit; the processing unit is used to adjust the α-axis and the β-axis according to the rotation angle of the turntable to be measured and the rotation angle of the regular 23-sided prism, so that the pyramidal difference between the rotation axis of the regular 23-sided prism and the rotation axis of the turntable to be measured is minimized.

[0014] Furthermore, the angle error between adjacent working angles of the regular 23-sided prism is ±100 arc seconds.

[0015] Furthermore, the rotation range of the electric two-dimensional adjustment mechanism is not less than ±1°, and the adjustment resolution is not greater than 10 arc seconds.

[0016] Furthermore, the acquisition delay of the synchronous sampling unit is no more than 1 ms.

[0017] At the same time, the present invention also provides a method for automatically detecting the measurement accuracy of the turntable angular position, which is special in that it includes the following steps:

[0018] 1] Prepare the above-mentioned automatic detection device for measuring the angular position accuracy of a turntable, and perform self-calibration on it;

[0019] 2] Position the turntable to be tested at 0°, align the autocollimator with the first working surface of the regular 23-faceted prism, and reset the X-axis and Y-axis readings of the autocollimator to zero;

[0020] 3] Drive the turntable to be tested to rotate at its rated speed. During the rotation process, the autocollimator is used to monitor the rotation angle ai of the regular 23-faceted prism in real time, and the synchronous sampling unit is used to monitor the rotation angle θi of the turntable to be tested in real time;

[0021] When the synchronous sampling unit detects that the rotation angle θi of the turntable to be tested rotates to the working angle of the regular 23-faceted prism, the synchronous sampling unit generates a trigger signal and transmits it to the autocollimator. The autocollimator sends the rotation angle ai of the regular 23-faceted prism to the synchronous sampling unit. The synchronous sampling unit packages the rotation angle θi of the turntable to be tested and the rotation angle ai of the regular 23-faceted prism and sends them to the processing unit; i represents the working face number of the regular 23-faceted prism, i=1,2,3…23; the rotation angle ai of the regular 23-faceted prism is the X-axis display value of the autocollimator;

[0022] 4] The processing unit calculates the measurement error ei of the angular position of the measuring point of the turntable to be measured according to the rotation angle θi of the turntable to be measured, the X-axis display value ai of the autocollimator and the correction value bi of the working surface of the regular 23-faceted prism, until the turntable to be measured rotates one circle, and the measurement errors of the angular positions of 23 measuring points are obtained;

[0023] 5] The processing unit calculates the angular position measurement accuracy of the turntable to be measured based on the maximum and minimum values ​​of the angular position measurement errors of the 23 measuring points, and completes the automatic detection of the angular position measurement accuracy of the turntable.

[0024] Further, step 1] is specifically as follows:

[0025] 1.1. Power on the turntable to be tested and position it to 0° and keep it;

[0026] 1.2. Turn on the autocollimator and align it with the first working surface of the regular 23-faceted prism;

[0027] 1.4. Drive the turntable to be tested to rotate the regular 23-face prism to the 1st working surface, the 7th working surface, the 13th working surface, and the 19th working surface respectively through the electric 2D adjustment mechanism and the tooling axis, and use the autocollimator to collect the Y-axis readings of the corresponding working surfaces to obtain Y1, Y7, Y13, and Y19;

[0028] 1.5. The processing unit calculates the adjustment values ​​Δα and Δβ of the α-axis and β-axis according to the Y-axis readings Y1, Y7, Y13 and Y19;

[0029] 1.6. Determine whether the absolute values ​​of Δα and Δβ are greater than 60 arc seconds at the same time:

[0030] If yes, the processing unit adjusts the α-axis and the β-axis according to the adjustment amounts Δα and Δβ, and returns to step 1.4; if no, the self-calibration of the turntable angular position measurement accuracy automatic detection device ends.

[0031] Furthermore, step 1.5 is specifically as follows:

[0032] The processing unit calculates the adjustment amounts Δα and Δβ of the α-axis and β-axis of the electric two-dimensional adjustment mechanism according to the Y-axis readings Y1, Y7, Y13 and Y19 by the following formula;

[0033]

[0034] Further, step 4] is specifically as follows:

[0035] The processing unit calculates the measurement error ei of the angular position of the measuring point of the turntable to be measured according to the rotation angle value θi of the turntable to be measured, the X-axis display value ai of the autocollimator 9 and the correction value bi of the working surface of the regular 23-faceted prism:

[0036]

[0037] Among them, when the direction of the rotation angle increase of the turntable to be measured is consistent with the positive direction of the X-axis of the autocollimator, the sign before ai is +, otherwise it is -.

[0038] Further, step 5] is specifically as follows:

[0039] The processing unit calculates the maximum value ei of the angular position measurement errors of the 23 measuring points max and the minimum value ei min , calculate the angular position measurement accuracy e of the turntable to be measured by the following formula:

[0040]

[0041] Complete automatic detection of turntable angular position measurement accuracy.

[0042] Beneficial effects of the present invention:

[0043] 1. The present invention discloses an automatic detection device for the angular position measurement accuracy of a turntable. A regular 23-sided prism is a standard part, and its 23 side surfaces are all reflection surfaces, i.e., working surfaces. The normal angle between two adjacent working surfaces is 360° / 23. The device can automatically perform self-calibration on the turntable to be measured; a synchronous sampling unit can be used to simultaneously trigger the autocollimator and the turntable to be measured, so that synchronous data acquisition can be realized and stored in a processing unit; according to corresponding instructions of the processing unit, the α-axis and β-axis of the electric two-dimensional adjustment mechanism are rotated by a specified adjustment amount, and finally the non-parallelism (pyramidal error) between the rotation axis of the regular 23-sided prism and the rotation axis of the turntable to be measured is automatically adjusted to a controllable range that does not affect the measurement accuracy, thereby realizing dynamic angular position measurement accuracy detection.

[0044] 2. The present invention provides an automatic detection device for the measurement accuracy of the turntable angular position, and each component thereof can be independently calibrated regularly in a metrology and calibration department, which can ensure the accuracy and fairness of the detection and testing of the device of the present invention.

[0045] 3. The automatic detection device for measuring the angular position of a turntable of the present invention is convenient for adjustment after self-calibration, and has fast and reliable detection and high repeatability.

[0046] 4. The automatic detection device for measuring the angular position accuracy of a turntable of the present invention only requires a synchronous sampling device to have a sampling function, and its acquisition delay is no more than 1ms. It is easy to implement and has high operability.

[0047] 5. The present invention provides a method for automatically detecting the angular position measurement accuracy of a turntable, which utilizes a synchronous sampling unit, a processing unit, and an autocollimator to objectively, accurately, and quickly detect the angular position measurement accuracy of the turntable to be measured.

[0048] 6. The automatic detection method of the turntable angular position measurement accuracy of the present invention can detect the dynamic angular position measurement accuracy (ie, the accuracy during the rotation process). The previous method can only detect the static angular position measurement accuracy.

[0049] 7. The present invention provides an automatic detection method for the angular position measurement accuracy of a turntable, which can be automatically adjusted throughout the whole process. The adjustment speed depends on the time it takes for a regular 23-sided prism to rotate through four sampling surfaces. The traditional method manually adjusts the 23 working surfaces of the regular 23-sided prism, and needs to stop and record the angle between the turntable to be tested and the autocollimator every time a working surface is rotated. The test speed depends entirely on the operator's adjustment of the pyramidal error when manually aligning each surface. When the dynamic angular measurement accuracy of the turntable to be tested is to be measured, it is even more impossible to measure; when using an autocollimator for monitoring or using a dial indicator and a micrometer for detection, there is no set of effective general methods, and the adjustment speed and accuracy depend entirely on the operator's technical level; compared with the traditional method, the method of the present invention completes the detection of the angular measurement accuracy of the turntable to be tested through self-calibration and automatic detection, thereby greatly improving work efficiency.

[0050] 8. The present invention provides a method for automatically detecting the measurement accuracy of the turntable angular position. It does not require the autocollimator to have a high sampling rate. It only needs to record the current sampling value after it receives a trigger signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a structural schematic diagram of an embodiment of a turntable angular position measurement accuracy automatic detection device of the present invention.

[0052] Description of reference numerals:

[0053] 1-tooling axis, 2-regular 23-faceted prism, 3-electric two-dimensional adjustment mechanism, 4-α axis, 5-β axis, 6-turntable to be measured, 7-synchronous sampling unit, 8-processing unit, 9-autocollimator. DETAILED DESCRIPTION

[0054] like Figure 1 The invention discloses an automatic detection device for the measurement accuracy of the angular position of a turntable, comprising a synchronous sampling unit 7, a processing unit 8, an autocollimator 9, a tooling axis 1, a regular 23-sided prism 2, and an electric two-dimensional adjustment mechanism 3; the regular 23-sided prism 2 is sleeved on the tooling axis 1, and its working surface is arranged opposite to the autocollimator 9; the inner center of the electric two-dimensional adjustment mechanism 3 is located in the same horizontal plane and is provided with an α-axis 4 and a β-axis 5 for adjusting the rotation angle of the electric two-dimensional adjustment mechanism 3 along the α-axis 4 and the β-axis 5 respectively; the upper surface of the electric two-dimensional adjustment mechanism 3 is vertically fixedly connected to the tooling axis 1, and the lower surface is coaxially fixedly connected to the upper surface of the turntable 6 to be measured.

[0055] The synchronous sampling unit 7 is respectively connected to the turntable 6 to be tested, the processing unit 8, and the autocollimator 9 for communication. The autocollimator 9 is used to collect the rotation angle of the regular 23-sided prism 2 when receiving the trigger signal from the synchronous sampling unit 7; the synchronous sampling unit 7 is used to collect the rotation angle of the turntable 6 to be tested, and when the turntable 6 to be tested rotates to the working angle of the regular 23-sided prism 2 (the angle of each rotation of the regular 23-sided prism 2 is 360° / 23), the trigger signal is sent to the autocollimator 9, and the turntable 6 to be tested rotates to the working angle of the regular 23-sided prism 2. The rotation angle of the measuring turntable 6 and the rotation angle of the regular 23-sided prism 2 collected by the autocollimator 9 are packaged and sent to the processing unit 8; the processing unit 8 is used to adjust the α-axis 4 and the β-axis 5 according to the rotation angle of the turntable 6 to be measured and the rotation angle of the regular 23-sided prism 2, so that the pyramidal difference between the rotation axis of the regular 23-sided prism 2 and the rotation axis of the turntable 6 to be measured is minimized, that is, the α-axis 4 and the β-axis 5 are both used to adjust the non-parallelism between the rotation axis of the regular 23-sided prism 2 and the rotation axis of the turntable 6 to be measured, that is, the pyramidal difference.

[0056] Preferably, the central axis of the tooling shaft 1 coincides with the central axis of the turntable 6 to be tested; the electric two-dimensional adjustment mechanism 3 is a commercially available product, and its rotation range is not less than ±1°, and the adjustment resolution is not greater than 10 arc seconds, which can improve the accuracy and speed of pyramidal error adjustment; the acquisition delay of the synchronous sampling unit 7 is not greater than 1ms. Since the angular output frequency of most turntables 6 to be tested is 1kHz, the acquisition delay of no more than 1ms can ensure that the rotation angle of the turntable 6 to be tested at the current moment and the rotation angle of the regular 23-sided prism 2 collected by the autocollimator 9 are the same time data.

[0057] The turntable 6 to be tested is driven to start unidirectional continuous rotation, and the synchronous sampling unit 7 is used to collect the rotation angle value of the turntable 6 to be tested and the Y-axis reading of the rotation angle of the regular 23-sided prism 2 collected by the autocollimator 9 when the regular 23-sided prism 2 rotates to the first working surface, the seventh working surface, the thirteenth working surface, and the nineteenth working surface. The processing unit 8 calculates the adjustment amount of the α-axis 4 and the β-axis 5 of the electric two-dimensional adjustment mechanism 3 according to the Y-axis reading of the autocollimator 9 collected, until the adjustment amount is not greater than 60 arc seconds at the same time, the adjustment is completed (according to the research results of relevant literature, it is generally adjusted to within 300 arc seconds, and the error caused by the pyramidal error can be controlled within 0.5 arc seconds. Since the working surface of the regular 23-sided prism 2 is small and the field of view of the autocollimator 9 is limited, in order to prevent the regular 23-sided prism 2 from rotating to other working surfaces to ensure that there are readings in the field of view of the autocollimator 9, the pyramidal error is adjusted as small as possible, and the adjustment accuracy of 60 arc seconds can be well met in terms of control and timeliness).

[0058] After the adjustment is completed, the first working surface of the regular 23-sided prism 2 is re-aligned with the autocollimator 9, and the angular position measurement accuracy of the turntable 6 to be tested is detected. The turntable 6 to be tested is driven to rotate continuously in one direction at the rated speed. When the synchronous sampling unit 7 detects that the rotation angle θi of the turntable 6 to be tested is rotated to the working angle of the regular 23-sided prism 2, the synchronous sampling unit 7 generates a trigger signal and transmits it to the turntable 6 to be tested and the autocollimator 9 at the same time until the turntable 6 to be tested rotates one circle, and then the angular position measurement accuracy of the turntable 6 to be tested is calculated using the collected rotation angle.

[0059] Each component of the present invention can be independently calibrated regularly in a metrology and calibration department, thereby ensuring the accuracy and fairness of the detection and testing of the device of the present invention.

[0060] At the same time, the present invention also provides a method for automatically detecting the measurement accuracy of the turntable angular position, comprising the following steps:

[0061] 1] Prepare the above-mentioned automatic detection device for the angular position measurement accuracy of the turntable and perform self-calibration on it, specifically:

[0062] 1.1. Power on the turntable 6 to be tested and position it to 0° and keep it there;

[0063] 1.2. Turn on the autocollimator 9 and align it with the first working surface of the regular 23-face prism 2. The autocollimator 9 has readings on both the X-axis and the Y-axis;

[0064] 1.4. Drive the turntable 6 to be tested to rotate the regular 23-face prism 2 to the first working surface, the seventh working surface, the thirteenth working surface, and the nineteenth working surface respectively through the electric two-dimensional adjustment mechanism 3 and the tooling axis 1, and at the same time use the autocollimator 9 to collect the Y-axis readings of the corresponding working surfaces to obtain Y1, Y7, Y13, and Y19;

[0065] 1.5. The processing unit 8 calculates the adjustment values ​​Δα and Δβ of the α-axis 4 and the β-axis 5 according to the Y-axis readings Y1, Y7, Y13 and Y19:

[0066]

[0067]

[0068] 1.6. Determine whether the absolute values ​​of Δα and Δβ are greater than 60 arc seconds at the same time:

[0069] If yes, the processing unit 8 adjusts the α-axis 4 and the β-axis 5 according to the calculated adjustment amounts Δα and Δβ, and returns to step 1.4; if no, the self-calibration of the turntable angular position measurement accuracy automatic detection device ends;

[0070] 2] Position the turntable 6 to be tested at 0°, align the autocollimator 9 with the first working surface of the regular 23-faceted prism 2, and clear the X-axis reading and Y-axis reading of the autocollimator 9 to zero;

[0071] 3] Drive the turntable 6 to rotate at its rated speed. During the rotation, the autocollimator 9 is used to monitor the rotation angle ai of the regular 23-faceted prism 2 in real time. Meanwhile, the synchronous sampling unit 7 is used to monitor the rotation angle θi of the turntable 6 in real time.

[0072] When the synchronous sampling unit 7 detects that the rotation angle θi of the turntable 6 to be tested rotates to the working angle of the regular 23-sided prism, the synchronous sampling unit 7 generates a trigger signal and transmits it to the autocollimator 9. The autocollimator 9 sends the rotation angle ai of the regular 23-sided prism 2 at this moment to the synchronous sampling unit 7. The synchronous sampling unit 7 packages the rotation angle θi of the turntable 6 to be tested at this moment and the rotation angle ai of the regular 23-sided prism 2 to the processing unit 8; i represents the working surface number of the regular 23-sided prism 2, i=1,2,3...23; the rotation angle ai of the regular 23-sided prism 2 is the X-axis display value of the autocollimator 9;

[0073] In this embodiment, the theoretical angle error between the current working surface of the regular 23-sided prism 2 and its next working surface is ±100 arc seconds, in order to improve the measurement accuracy and the alignment tolerance of each working surface of the regular 23-sided prism 2 and the autocollimator 9.

[0074] 4] The processing unit 8 calculates the measurement error ei of the measuring point angular position of the turntable 6 to be measured according to the rotation angle value θi of the turntable 6 to be measured, the X-axis display value ai of the autocollimator 9 and the correction value bi of the working surface of the regular 23-faceted prism 2:

[0075]

[0076] In the formula, the correction value bi of each working surface of the regular 23-face prism 2 is verified by the superior metrological organization and is a known item; when the rotation angle increasing direction of the turntable 6 to be measured is consistent with the positive direction of the X-axis of the autocollimator 9, the sign before ai is +, otherwise it is -;

[0077] 5] The processing unit 8 calculates the maximum value ei among the angular position measurement errors of the 23 measuring points max and the minimum value ei min , the angular position measurement accuracy e of the turntable 6 to be measured is calculated by the following formula:

[0078]

[0079] Complete automatic detection of turntable angular position measurement accuracy.

[0080] The automatic detection method for the angular position measurement accuracy of the turntable of the present invention does not require the autocollimator 9 to have a high sampling rate. It only needs to record the current sampling value after it receives the trigger signal, and only requires the acquisition delay of the synchronous sampling unit 7 to be no more than 1ms. It is easy to implement and has high operability. The method completes the detection of the angular measurement accuracy of the turntable 6 to be measured through self-calibration and automatic detection, which greatly improves the work efficiency.

Claims

1. A turntable angular position measurement accuracy automatic detection device, characterized in that: It comprises a synchronous sampling unit (7), a processing unit (8), an autocollimator (9), a tooling axis (1), a regular 23-faceted prism (2), and an electric two-dimensional adjustment mechanism (3); The regular 23-sided prism (2) is sleeved on the tooling shaft (1), and its working surface is arranged opposite to the autocollimator (9); The inner center of the electric two-dimensional adjustment mechanism (3) is located on the same horizontal plane and is provided with mutually perpendicular α-axis (4) and β-axis (5), which are used to adjust the rotation angle of the electric two-dimensional adjustment mechanism (3) along the α-axis (4) and the β-axis (5), respectively; the center of the upper surface of the electric two-dimensional adjustment mechanism (3) is vertically fixed to the tooling axis (1), and the lower surface is coaxially fixed to the upper surface of the turntable (6) to be measured; the α-axis (4) and the β-axis (5) are respectively connected to the processing unit (8) for communication; The synchronous sampling unit (7) is respectively connected to the turntable to be measured (6), the processing unit (8) and the autocollimator (9) in communication; the autocollimator (9) is used to collect the rotation angle of the regular 23-sided prism (2) when receiving a trigger signal sent by the synchronous sampling unit (7); the synchronous sampling unit (7) is used to collect the rotation angle of the turntable to be measured (6), and send a trigger signal to the autocollimator (9) when the turntable to be measured (6) rotates to the working angle of the regular 23-sided prism (2), and packages the rotation angle of the turntable to be measured (6) and the rotation angle of the regular 23-sided prism (2) collected by the autocollimator (9) and sends them to the processing unit (8); the processing unit (8) is used to adjust the α axis (4) and the β axis (5) according to the rotation angle of the turntable to be measured (6) and the rotation angle of the regular 23-sided prism (2), so that the pyramidal difference between the rotation axis of the regular 23-sided prism (2) and the rotation axis of the turntable to be measured (6) is minimized.

2. The automatic detection device for measuring the angular position of a turntable according to claim 1, characterized in that: The angle error between adjacent working angles of the regular 23-sided prism (2) is ±100 arc seconds.

3. The automatic detection device for measuring the angular position of a turntable according to claim 2, characterized in that: The rotation range of the electric two-dimensional adjustment mechanism (3) is not less than ±1°, and the adjustment resolution is not greater than 10 arc seconds.

4. The automatic detection device for measuring the angular position accuracy of a turntable according to claim 1, 2 or 3, characterized in that: The acquisition delay of the synchronous sampling unit (7) is no more than 1 ms.

5. A method for automatically detecting the angular position measurement accuracy of a turntable, characterized in that: The following steps are involved: 1] Prepare a turntable angular position measurement accuracy automatic detection device as described in any one of claims 1 to 4, and perform self-calibration on it; 2] Positioning the turntable (6) to be measured at 0°, aligning the autocollimator (9) with the first working surface of the regular 23-faceted prism (2), and clearing the X-axis reading and Y-axis reading of the autocollimator (9) to zero; 3] driving the turntable (6) to be tested to rotate at its rated speed, and during the rotation process, using the autocollimator (9) to monitor the rotation angle ai of the regular 23-faceted prism (2) in real time, and using the synchronous sampling unit (7) to monitor the rotation angle θi of the turntable (6) to be tested in real time; When the synchronous sampling unit (7) detects that the rotation angle θi of the turntable (6) to be tested rotates to the working angle of the regular 23-sided prism (2), the synchronous sampling unit (7) generates a trigger signal and transmits it to the autocollimator (9). The autocollimator (9) sends the rotation angle ai of the regular 23-sided prism (2) at this moment to the synchronous sampling unit (7). The synchronous sampling unit (7) packages the rotation angle θi of the turntable (6) to be tested and the rotation angle ai of the regular 23-sided prism (2) at this moment and sends them to the processing unit (8); i represents the working face number of the regular 23-sided prism (2), i=1, 2, 3...23; the rotation angle ai of the regular 23-sided prism (2) is the X-axis display value of the autocollimator (9); 4] The processing unit (8) calculates the measurement error ei of the angular position of the measuring point of the turntable (6) to be measured according to the rotation angle θi of the turntable (6) to be measured, the X-axis display value ai of the autocollimator (9) and the correction value bi of the working surface of the regular 23-sided prism (2), until the turntable (6) to be measured rotates one circle, and the measurement errors of the angular positions of 23 measuring points are obtained; 5] The processing unit (8) calculates the angular position measurement accuracy of the turntable (6) to be measured based on the maximum and minimum values ​​of the angular position measurement errors of the 23 measurement points, and completes the automatic detection of the angular position measurement accuracy of the turntable.

6. The method for automatically detecting the angular position measurement accuracy of a turntable according to claim 5, characterized in that: Step 1] Specifically: 1.

1. Power on the turntable (6) to be tested and position it to 0° and keep it there; 1.

2. Turn on the autocollimator (9) to align the autocollimator (9) with the first working surface of the regular 23-faceted prism (2); 1.

4. Drive the rotating table (6) to be tested to rotate the regular 23-faceted prism (2) to the first working surface, the seventh working surface, the thirteenth working surface and the nineteenth working surface respectively through the electric two-dimensional adjustment mechanism (3) and the tooling shaft (1), and at the same time use the autocollimator (9) to collect the Y-axis readings of the corresponding working surfaces to obtain Y1, Y7, Y13 and Y19; 1.

5. The processing unit (8) calculates the adjustment values ​​Δα and Δβ of the α-axis (4) and the β-axis (5) according to the Y-axis readings Y1, Y7, Y13 and Y19; 1.

6. Determine whether the absolute values ​​of Δα and Δβ are greater than 60 arc seconds at the same time: If yes, the processing unit (8) adjusts the α-axis (4) and the β-axis (5) according to the adjustment amounts Δα and Δβ, and returns to step 1.4; if no, the self-calibration of the turntable angular position measurement accuracy automatic detection device ends.

7. The method for automatically detecting the angular position measurement accuracy of a turntable according to claim 6, characterized in that: Step 1.5 is as follows: The processing unit (8) calculates the adjustment amounts Δα and Δβ of the α-axis (4) and the β-axis (5) of the electric two-dimensional adjustment mechanism (3) according to the Y-axis readings Y1, Y7, Y13 and Y19 by the following formula; 8. The method for automatically detecting the angular position measurement accuracy of a turntable according to claim 7, characterized in that: Step 4] Specifically: The processing unit (8) calculates the measurement error ei of the angular position of the measuring point of the turntable (6) to be measured according to the rotation angle value θi of the turntable (6) to be measured, the X-axis display value ai of the autocollimator (9) and the correction value bi of the working surface of the regular 23-faceted prism (2): When the direction in which the rotation angle of the turntable (6) to be measured increases is consistent with the positive direction of the X-axis of the autocollimator (9), the sign before ai is +, otherwise it is -.

9. The method for automatically detecting the angular position measurement accuracy of a turntable according to claim 8, characterized in that: Step 5] Specifically: The processing unit (8) calculates the maximum value ei among the angular position measurement errors of the 23 measuring points. max and the minimum value ei min , the angular position measurement accuracy e of the turntable (6) to be measured is calculated by the following formula: Complete automatic detection of turntable angular position measurement accuracy.

Images