A bore scanning error correction and sun and moon line identification method

Abstract

The application discloses a bore scanning error correction and identification method for lands and grooves, and belongs to the technical field of bore scanning, which comprises the following steps: firstly, acquiring multi-path measurement data of lands and grooves, performing elliptical fitting on single-path data, correcting eccentricity error, correcting installation inclination error of a rotating platform after rotating the ellipse, preliminarily aligning the multi-path data according to installation angle intervals, setting single-frequency measurement according to the number of lands and grooves of a barrel, calculating the phase difference between data by single-frequency measurement, obtaining the sampling point number of the offset between four groups of data, correcting the installation angle error of the multi-path data after alignment, and fusing the multi-path data; finally, using the differential or sliding window method to obtain the inflection points of the profile of the fused data, and obtaining the profile of lands and grooves. The application can correct installation error by processing the data of multiple sensors, improve the detection accuracy, and effectively identify the lands and grooves of the bore of a gun.

Description

Technical Field

[0001] This invention relates to the field of borehole scanning technology, and in particular to a method for borehole scanning error correction and positive / negative line identification. Background Technology

[0002] After prolonged use, artillery shells develop defects such as burning, wear, cracks, broken calipers, severe copper plating, and corrosion within the bore, directly impacting firing accuracy, lifespan, and safety. Therefore, bore inspection is essential before and after firing. In practical applications, sensor data is often affected by various errors, especially installation errors. Developing effective data processing algorithms to correct these errors is crucial for improving measurement accuracy. Data processing can effectively correct installation errors, including eccentricity errors of the rotation center, sensor installation tilt errors, and radial angular deviations between multiple sensors, thereby improving measurement accuracy. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing a method for correcting bore scanning errors and identifying bore defects. This method can correct installation errors by processing data from multiple sensors, improving detection accuracy and effectively identifying bore defects in artillery. This method uses an error model-based correction algorithm to achieve automatic detection and quantitative analysis of bore defects in artillery, thereby improving the reliability and safety of artillery use.

[0004] The present invention achieves the above objectives through the following technical solutions:

[0005] A method for correcting in-bore scanning errors and identifying positive and negative lines includes the following steps:

[0006] First, a multi-channel in-bearing scanning device is used to acquire multiple channels of data, with a data size of m×n:

[0007]

[0008] Assuming the in-bore scanning device is equipped with n sensors, in equation (1), d1 d2d n These represent the outputs of n sensors, where m is the number of data points acquired in one revolution of a single channel.

[0009] Let θ be the difference in installation angle between the nth group and the 1st group of sensors. i , Then the first i data points of the nth group need to be moved to the end of the channel data to initially align the sensor data.

[0010] l n =[d i+1,n d i+2,n …d m,n d1,n … d i,n ] T (13)

[0011] Where, d i,n Let l represent the i-th point in the n-th data set. n The sensor data after initial alignment;

[0012] D1 = [l1 l2 … l] n (14)

[0013] After converting the data to a Cartesian coordinate system, the single-path data for the nth group is:

[0014]

[0015] In equation (4), (x k,n ,y k,n ) represents the rectangular coordinate of the k-th data in the n-th data set.

[0016] Preferably, the data obtained from each single channel in equation (4) are fitted with an ellipse to obtain the center position (x0, y0) of the ellipse. The angle of the major axis relative to the positive x-direction is θ0, and the ratio of the major axis to the minor axis is A. After subtracting the center coordinate from the rectangular coordinate data, the rectangular coordinate data is rotated using a rotation matrix so that the center of the ellipse is located at the origin of the rectangular coordinate system and the major axis of the ellipse is located on the x-axis. In this way, the test error caused by the eccentricity of the rotation center of the borehole scanning device can be corrected.

[0017]

[0018] In equation (5), (x' k,n ,y' k,n ) represents the coordinates of the k-th sampling point after correcting for eccentricity error in the n-th data set.

[0019] Preferably, the data (x') obtained from the nth group of data obtained by equation (5) after correcting for eccentricity error is... k ,y' k Using the scaling matrix of affine transformation, a matrix is ​​constructed based on the major-minor axis ratio A of the ellipse. The resulting data has a contour in the rectangular coordinate system that approximates a perfect circle. This is used to correct measurement errors caused by the sensor tilt angle of the borehole scanning device.

[0020]

[0021] In equation (6) This represents the coordinates of the k-th sampling point after correcting for tilt error in the n-th data set.

[0022] Preferably, the coordinates in equation (6) are converted into polar coordinate data:

[0023]

[0024] l' n =[l 1,n l 2,n … l k,n ] T (19)

[0025] D2=[l'1 l'2l' n (20)

[0026] In equation (7), [l k,n θ k,n ] represents the kth data point transformed from the nth data set to polar coordinates, where l' in equation (8) n For the nth set of data after conversion to polar coordinates, D2 in equation (9) represents all channel data after conversion to polar coordinates.

[0027] Preferably, based on the number of positive and negative wires in the tube, single-frequency measurement is set for the data D2 after conversion to polar coordinates. Let the number of positive and negative wires be j, the sampling time be t, then the dominant frequency is j / t, and the phase φ between the nth group of single-frequency measurement data is calculated. n The formula for obtaining the offset number of the nth data group relative to the first data group is:

[0028]

[0029] Where, Δt n Let n be the offset point of the nth data group relative to the first data group.

[0030]

[0031] D3 = [l1”l2” … l n "] (twenty one)

[0032] Among them l' k,n Indicates l' k The nth data point, l n "This is the nth set of data obtained after processing the phase deviation; the full-channel data is D3."

[0033] Preferably, a multi-channel data fusion method is used on data D3, including but not limited to methods such as calculating the mean and screening for outliers, to obtain:

[0034]

[0035] R = [a1 a2…a] m ] T

[0036] Among them, a mThis represents the fusion processing result of the m-th sampling point in all channels, f represents the fusion processing method, and R represents a set of data of length m in the final output.

[0037] Then, using the difference or sliding window method, the inflection points of the contour are obtained from the data R, and the contour of the positive line is obtained from the data between the inflection points.

[0038] Compared with the prior art, the present invention has the following beneficial technical effects:

[0039] 1) The in-bore scanning error correction method proposed in this invention is based on an error geometry model, taking into account eccentricity, tilt angle and radial angle errors, and provides an error correction method with high interpretability.

[0040] 2) This invention corrects and fuses multiple data streams separately, which greatly improves the reliability of the data, eliminates outliers, and reduces the impact of sensor installation errors in the radial position. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is the original waveform diagram of an embodiment of the present invention;

[0043] Figure 2 This is a polar coordinate diagram of the original waveform containing eccentricity and tilt angle errors in an embodiment of the present invention;

[0044] Figure 3 This is a rectangular coordinate profile diagram containing eccentricity and tilt angle errors in an embodiment of the present invention;

[0045] Figure 4 This is a rectangular coordinate profile diagram of the corrected eccentricity and tilt angle errors in an embodiment of the present invention;

[0046] Figure 5 This is a waveform diagram of four channels with phase difference in an embodiment of the present invention;

[0047] Figure 6 This is a waveform diagram of the four-way alignment in an embodiment of the present invention;

[0048] Figure 7 This is a modified outline diagram of an embodiment of the present invention;

[0049] Figure 8 This is a diagram showing the outline of the yin and yang lines in an embodiment of the present invention. Detailed Implementation

[0050] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0051] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0052] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, method, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive, either alone or selectively, with other embodiments.

[0053] Furthermore, the present invention will be described in detail with reference to the schematic diagrams. When describing the embodiments of the present invention in detail, the schematic diagrams are merely examples for ease of explanation and should not limit the scope of protection of the present invention.

[0054] Example 1

[0055] like Figure 1-8 As shown, the present invention proposes a method for correcting in-bore scanning errors and identifying positive and negative lines, which includes the following steps:

[0056] First, multiple measurement data are acquired; in this embodiment, four channels are used. Due to inaccurate centering, the data curves exhibit a sinusoidal shape, such as... Figure 1 As shown, its data is converted to polar coordinates as follows: Figure 2 As shown;

[0057] In this embodiment, the in-bore scanning device is equipped with 4 sensors, with a sampling time of 288 seconds, a sampling rate of 100 Hz, and a data size of 28800 × 4.

[0058] Let θ be the difference in installation angle between the nth group and the 1st group of sensors. i , Then the first i sampling points of the nth group need to be moved to the end of the channel data to initially align the sensor data.

[0059] Convert the initially aligned single-path data into Cartesian coordinate system data, such as Figure 3 As shown;

[0060] For each individual data stream, ellipse fitting is performed to determine the ellipse's center position, the angle of the major axis relative to the positive x-axis, and the ratio of the major to minor axes. After subtracting the center coordinates from the rectangular coordinate data, a rotation matrix is ​​used to rotate the rectangular coordinate data so that the ellipse's center is located at the origin of the rectangular coordinate system and the major axis lies on the x-axis. This method can correct for testing errors caused by the eccentricity of the rotation center in the borehole scanning equipment. Figure 4 As shown.

[0061] The data was converted back to polar coordinates, with the sampling time on the horizontal axis and the distance on the vertical axis, resulting in a horizontal waveform envelope. The dominant frequencies were those of the yin and yang lines. This corrected the error caused by the installation tilt angle. However, phase differences still exist in the four data streams. This is mainly due to deviations in the installation angle of the ranging sensor. Figure 5 As shown.

[0062] Based on the number of positive and negative lines on the tube, single-frequency measurements are set for the data after conversion to polar coordinates, such as... Figure 5 In the data, the number of positive and negative lines is 48, so the main frequency is 48 / 288 = 0.1666 Hz. The phase difference between the data is calculated by single-frequency measurement, and the number of sampling points of the offset between the four sets of data is obtained.

[0063] Align the four sets of data, and use averaging or outlier removal methods to obtain phase-aligned data A, such as... Figure 6 As shown.

[0064] Transform to polar coordinates to obtain the contour map, as shown below. Figure 7 As shown.

[0065] Then, using the difference or sliding window method, the inflection points of the contour are obtained to get the contour of the yin-yang line.

[0066] Transform to polar coordinates to obtain the outline of the yin-yang lines, as shown below. Figure 8 As shown; at this point, all the data for bearish and bullish candlesticks can be obtained.

[0067] In this embodiment, the wear amount can be obtained by calculating the average of the negative and positive marks. By comparing the data of the negative and positive marks with the data of various positions in the barrel, the wear amount at different positions can be obtained. This invention can measure whether there is an ablation problem in the barrel. When there is an abnormal protrusion or abnormal defect on the positive mark, or the measured radius exceeds the normal range, it can be determined that the wear amount is too large, there is a missing part or ablation deposits, and the barrel needs to be repaired or replaced.

[0068] This invention uses multiple laser sensors to eliminate each other's errors, thereby ensuring data integrity. Even if one laser sensor fails to measure data at a certain point, the other three laser sensors can still measure and correct the data, improving measurement accuracy.

[0069] Due to installation errors, specifically issues with the laser sensor installation, the data may contain an overall error. This problem can be solved by averaging the values ​​from the four laser sensors, thus reducing the impact of installation errors. Furthermore, centering issues can be corrected by elliptical fitting, and tilting issues can be resolved by correcting the elliptical shape back to a circular shape. This further reduces the impact of installation errors and improves measurement accuracy.

[0070] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A method for correcting in-bore scanning errors and identifying positive and negative lines, characterized in that, Includes the following steps: First, a multi-channel in-bearing scanning device is used to acquire multiple channels of data, with a data size of m×n: Assuming the in-bore scanning device is equipped with n sensors, in equation (1), d1 d2…d n These represent the outputs of n sensors, where m is the number of data points acquired in one revolution of a single channel. Let θ be the difference in installation angle between the nth group and the 1st group of sensors. i , Then the first i data points of the nth group need to be moved to the end of the channel data to initially align the sensor data. l n =[d i+1,n d i+2,n …d m,n d 1,n …d i,n ] T (2) Where, d i,n Let l represent the i-th point in the n-th data set. n The sensor data after initial alignment; D1＝[l1 l2 …l n ] (3) Convert the data to a Cartesian coordinate system. The single-path data for the nth group is: In equation (4), (x k,n ,y k,n ) represents the rectangular coordinate of the k-th data point in the n-th data set; l k,n Represents the nth data group l in D1 n The data is obtained from the k-th sensor. Ellipse fitting is performed on each individual data stream to determine the ellipse's center position, the angle of the major axis relative to the positive direction, and the ratio of the major and minor axes. The Cartesian coordinate data is subtracted from the center coordinates, and then rotated using a rotation matrix so that the ellipse's center is at the origin and the major axis is on the x-axis, resulting in data corrected for eccentricity. An affine transformation scaling matrix is ​​applied to the corrected eccentricity data, and a matrix is ​​constructed based on the ellipse's major-minor axis ratio, resulting in a data profile in the Cartesian coordinate system that approximates a perfect circle. Data corrected for tilt angle error is obtained. The data is converted to polar coordinates. Based on the number of yin and yang lines on the tube, single-frequency measurement is performed on the converted polar coordinate data to obtain the number of offset points between data points. The data is aligned and fused using multi-channel data fusion to obtain the fused data. The data is then analyzed using difference or sliding window methods to determine the inflection points of the profile, and the data between these inflection points is used to obtain the profile of the yin and yang lines.

2. The method for correcting in-bore scanning errors and identifying positive and negative lines according to claim 1, characterized in that, The data obtained from each single channel in equation (4) are fitted with an ellipse to obtain the center position (x0, y0) of the ellipse. The angle of the major axis relative to the positive x direction is θ0, and the ratio of the major and minor axes of the ellipse is A. After subtracting the center coordinates from the rectangular coordinate data, the rectangular coordinate data is rotated using a rotation matrix so that the center of the ellipse is located at the origin of the rectangular coordinates and the major axis of the ellipse is located on the x-axis. In this way, the test error caused by the eccentricity of the rotation center of the borehole scanning equipment can be corrected. In equation (5), (x' k,n ,y' k,n ) represents the coordinates of the k-th data after correcting for eccentricity error in the n-th data set.

3. The method for correcting in-bore scanning errors and identifying positive and negative lines according to claim 2, characterized in that, The data obtained from equation (5) after correcting for eccentricity error in the nth group of data (x') k ,y' k Using the scaling matrix of affine transformation, a matrix is ​​constructed based on the major-minor axis ratio A of the ellipse. The resulting data has a contour in the rectangular coordinate system that approximates a perfect circle. This is used to correct measurement errors caused by the sensor tilt angle of the borehole scanning device. In equation (6) This represents the coordinates of the k-th data point after correcting for tilt error in the n-th data set.

4. The method for correcting in-bore scanning errors and identifying positive and negative lines according to claim 3, characterized in that, Convert the data in equation (6) into polar coordinates: l' n ＝[l 1,n l 2,n …l k,n ] T (8) D2=[l'1 l'2…l' n ] (9) In equation (7) [l k,n θ k,n ] represents the kth data point transformed from the nth data set to polar coordinates, where l' in equation (8) n For the nth set of data after conversion to polar coordinates, D2 in equation (9) represents all channel data after conversion to polar coordinates.

5. The method for correcting bore scanning errors and identifying positive and negative lines according to claim 4, characterized in that, Based on the number of positive and negative wires in the tube, single-frequency measurements are set for the data D2 after conversion to polar coordinates. Let the number of positive and negative wires be j, and the sampling time be t, then the dominant frequency is j / t. The phase φ between the data in the nth group of single-frequency measurements is calculated. n The formula for obtaining the offset number of the nth data group relative to the first data group is: Where, Δt n Let n be the offset point of the nth data group relative to the first data group. Among them l' k,n Indicate l k The nth data point, l n "This is the nth set of data obtained after processing the phase deviation; the full-channel data is D3." 6. The method for correcting bore scanning errors and identifying positive and negative lines according to claim 5, characterized in that, Using multi-path data fusion methods on data D3, including but not limited to mean calculation and outlier screening methods, we obtain: Among them, a m This represents the fusion processing result of the m-th sampling point in all channels, f represents the fusion processing method, and R represents a set of data of length m in the final output. Then, using the difference or sliding window method, the inflection points of the contour are obtained from the data R, and the contour of the yin-yang line is obtained from the data between the inflection points.

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