A solid rocket engine coated grain silver wire position visual identification positioning method

Abstract

The present application relates to a kind of solid rocket engine coated grain silver wire position visual identification positioning method, comprising: collecting coated grain end surface silver wire image;Extract image ROI region;Identify image silver wire white dot;Image puffing treatment;Remove unqualified point;Using non-complete information silver wire point identification algorithm to obtain all silver wire coordinates;Drive actuator to move according to silver wire coordinates;Coated grain end surface is drilled and shaped.During the process of solid rocket engine coated grain end surface silver wire drilling and shaping, there is the phenomenon of incomplete visual measurement information, using non-complete information silver wire point identification algorithm to obtain all silver wire coordinates, can realize end surface silver wire shaping processing under the premise of missing most visual information.The method reduces process waiting time, and the success rate and efficiency of coated grain end surface silver wire drilling processing are high, can adapt to the drilling requirements of end surface metal wire with different number, strong adaptability and high reliability.

Description

Technical Field

[0001] This invention relates to the field of solid rocket motor coating propellant grain shaping and manufacturing, specifically a method for visually identifying and locating the position of silver wires in solid rocket motor coating propellant grains. Background Technology

[0002] With the continuous improvement of solid rocket motor propellant performance, the requirements for the shaping and manufacturing precision of solid rocket motor coated propellant grains are also becoming higher. Precise identification and machining positioning of the silver wire position is a crucial shaping and manufacturing process for improving the combustion speed and combustion surface of solid propellants, and its accuracy directly affects the performance of solid rocket motors.

[0003] Currently, manual face-to-face silver wire drilling suffers from problems such as poor quality consistency, low accuracy and reliability, low efficiency, and high safety risks. Existing silver wire recognition algorithms are all based on the successful identification of multiple silver wire points, making it difficult to adapt to intelligent detection and optimization when silver wire images are severely incomplete. However, in actual production, the phenomenon of severely missing silver wire point image information often occurs. Therefore, it is necessary to adopt a method that can adapt to visual recognition and precise positioning of silver wire positions under incomplete information to achieve precise drilling and shaping of silver wires on the end face of the propellant grain covering in solid rocket motors. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a method for visual recognition and precise positioning of the silver wire position of the propellant grain in a solid rocket motor under incomplete information, thereby enabling the drilling and shaping of the silver wire on the end face of the propellant grain in a solid rocket motor under incomplete information.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a method for visually identifying and locating the position of silver wires covering the propellant grains in a solid rocket motor, comprising:

[0006] Images of silver wires on the end face of the coated drug column were acquired and Gaussian filtered.

[0007] Extract the Region of Interest (ROI) from the silver wire image on the end face of the coated drug column;

[0008] Identify the white dots on the silver wires in the image of the coated drug column end face;

[0009] The image of the silver wires on the end face of the coated drug column was puffed.

[0010] A non-complete information silver wire point recognition algorithm was used to obtain the coordinate image of all silver wires.

[0011] The actuator moves according to the silver wire coordinate system;

[0012] Drilling and shaping are performed on the end face of the coated propellant column.

[0013] Furthermore, a close-up industrial camera was used to capture images of the silver wires on the end face of the coated propellant column.

[0014] Furthermore, wavelet transform was used to extract features of the ROI region of the silver wire on the end face of the coated drug column.

[0015] Furthermore, after performing the puffing process on the silver wire image of the coated drug column end face, the method further includes: removing defective points in the silver wire image of the coated drug column end face.

[0016] Furthermore, the incomplete information silver wire point recognition algorithm includes: performing silver wire point recognition for working conditions with a silver wire point count of 3≤i≤5 and for a silver wire point count of i≤2 respectively;

[0017] For working conditions where the number of silver wires is 3≤i≤5, silver wire identification is performed, including: calculating the center position of the silver wire on the end face using the least squares method, and calculating the coordinates of the missing silver wire on the end face using the interpolation method;

[0018] For the working condition where the number of silver wire points i≤2, silver wire point identification is performed, including: after identifying the center of the end face of the drug column, silver wire point identification is performed for the two working conditions where the number of silver wire points i=2 and the number of silver wire points i=1.

[0019] For the condition where the number of silver wire points i = 2, silver wire point identification is performed, including:

[0020] The coordinates of the silver wire points are used to calculate the positions of the two silver wire centers. The coordinates of the center of the end face of the medicine column are used to eliminate the incorrect silver wire centers and obtain the correct silver wire center positions. The coordinates of the missing silver wire positions on the end face are obtained by interpolation.

[0021] For the condition where the number of silver wire points i = 1, silver wire point identification is performed, including:

[0022] Using the center of the end face of the medicine column as the center of the silver wire, the coordinates of the missing silver wire on the end face are calculated by interpolation.

[0023] Furthermore, the model for calculating the center position p of the silver wire on the end face using the least squares method is as follows:

[0024]

[0025] Where, x j y j These are the coordinates of the identifiable silver wire, x a y a These are the coordinates of the center of the silver wire.

[0026] Furthermore, the calculation of the coordinates of the missing silver wire position on the end face using interpolation includes:

[0027] If the number of identified silver wire points i satisfies 3 ≤ i ≤ 5, then

[0028] calculate

[0029] Among them, S m S n The coordinates of the known silver wire point, S, are given. O =(x a ,y a ) represents the coordinates of the center of the silver wire; α i This represents the angle between the line connecting the known silver wire points m and n and the center of the circle;

[0030] if There are K-1 silver wire points between silver wire point m and silver wire point n, and K is calculated by the following formula:

[0031] Round() is the rounding function;

[0032] The coordinates of the kth undetermined silver thread point are S. k =(x k y k The following equation is obtained by solving:

[0033]

[0034] Where r is the radius of the fitted circle of the silver wire point; α k This represents the angle between the line connecting the k-th silver wire point and the known silver wire point m to the center of the circle.

[0035] Furthermore, when the number of silver wire points i = 2, the calculation of the coordinates of the missing silver wires on the end face using interpolation includes:

[0036] Calculate the coordinates S of the center of the silver wire O1 =(x o1 ,y o1 ), Where S m S n Given the coordinates of the known silver wire point, r1 is the radius of the circle containing the theoretical silver wire;

[0037] Calculate the angle α between the given silver wire point and the center of the circle. i :

[0038]

[0039] There are K-1 silver wire points between silver wire point m and silver wire point n, and K is calculated by the following formula:

[0040] The coordinates of the kth undetermined silver thread point are S. k =(x k y kThe following equation is obtained by solving:

[0041]

[0042] α k This represents the angle between the line connecting the k-th silver wire point and the known silver wire point m to the center of the circle.

[0043] Furthermore, when the number of silver wire points i = 1, the step of calculating the coordinates of the missing silver wire position on the end face using interpolation includes:

[0044] The coordinates S of the kth silver wire missing from the end face are calculated using interpolation. k =(x k y k The calculation formula is as follows:

[0045]

[0046] Where r1 is the radius of the circle containing the theoretical silver wire, S L Given the coordinates of the silver wire point, α k Let be the angle between the k-th silver wire point and the line connecting the known silver wire point to the center of the circle.

[0047] The advantages of this invention compared to the prior art are:

[0048] This invention discloses a visual recognition and positioning method for the position of silver wires on the propellant grain of a solid rocket motor. By analyzing and classifying the missing information in the visual image of the silver wires on the end face of the propellant grain, and using the available image data and corresponding calculation algorithms, the coordinate data of the silver wires under incomplete information is obtained, and the actuator is driven to drill holes, thereby achieving efficient and high-quality drilling and shaping of the position of the silver wires on the end face of the propellant grain of a solid rocket motor. Attached Figure Description

[0049] To more clearly illustrate the implementation method of the present invention, the drawings required for the implementation method will be briefly introduced below. The drawings described below are only for the implementation method of the present invention. For those skilled in the art, other drawings can be obtained from the drawings without creative effort.

[0050] Figure 1 This is a schematic diagram of the process of the present invention.

[0051] Figure 2 This is a flowchart illustrating the implementation of the incomplete information silver dot recognition algorithm.

[0052] Figure 3 The images of the silver wires on the front and back ends are processed using Gaussian filtering. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0054] This invention provides a method for visually identifying and locating the position of silver wires in the propellant grain of a solid rocket motor, comprising the following steps:

[0055] Step 1. Acquire images of the silver wires on the end face of the coated drug column;

[0056] Step 2. Extract the ROI region of the image;

[0057] Step 3. Identify the silver lines and white spots in the image;

[0058] Step 4. Image puffing processing;

[0059] Step 5. Remove defective points;

[0060] Step 6. Use an incomplete information silver wire point recognition algorithm to obtain the coordinate image of all silver wires;

[0061] Step 7. Drive the actuator to move according to the silver wire coordinates;

[0062] Step 8. Drill and shape the end face of the coated propellant column.

[0063] Step 1 involves acquiring images using a close-up industrial camera and applying Gaussian filtering to the images. The images of the silver wires on the front and rear faces after Gaussian filtering are shown below. Figure 3 As shown.

[0064] Step 2 uses wavelet transform to extract ROI features.

[0065] Step 6 includes the working conditions where the number of silver wire points is 3≤i≤5 and the working conditions where the number of silver wire points is i≤2.

[0066] For the working condition where the number of silver wire points is 3≤i≤5, the position of the center of the silver wire on the end face is calculated by the least squares method, and the coordinates of the missing silver wire on the end face are calculated by the interpolation method.

[0067] The model for calculating the center position p of the silver wire on the end face using the least squares method is as follows:

[0068]

[0069] Where, x j y j These are the coordinates of the identifiable silver wire, x a y a These are the coordinates of the center of the silver wire, i.e.

[0070]

[0071] The algorithm for calculating the position coordinates of the missing silver wire on the end face using interpolation is as follows:

[0072] If the number of identified silver wire points i satisfies 3 ≤ i ≤ 5, then

[0073] calculate Where S m S n The coordinates of the known silver wire point, S, are given. O =(x a ,y a ) represents the coordinates of the center of the silver wire; α i This represents the angle between the known silver wire points m and n and the line connecting them to the center of the circle.

[0074] if There are K-1 silver wire points between silver wire points m and n, and K is calculated by the following formula:

[0075]

[0076] Round() is the rounding function.

[0077] The coordinates of the kth undetermined silver thread point are S. k =(x k y k This can be obtained by solving the following equation:

[0078]

[0079] Where r is the radius of the fitted circle of the silver wire point, α k This represents the angle between the line connecting the k-th silver wire point and the known silver wire point m to the center of the circle.

[0080] The working condition where the number of silver wire points i≤2 is divided into two working conditions after identifying the center of the end face of the drug column: the number of silver wire points i=2 and the number of silver wire points i=1.

[0081] In the case where the number of silver wire points i=2, the coordinates of the silver wire points are used to calculate the positions of the two silver wire centers. One invalid silver wire center is eliminated by using the coordinates of the center of the end face of the medicine column, and the correct silver wire center position is obtained. The coordinates of the missing silver wire position on the end face are obtained by interpolation.

[0082] The interpolation algorithm for calculating the coordinates of the missing silver wire on the end face when i=2 is as follows:

[0083] Calculate the coordinates S of the center of the silver wire O1 =(x o1 ,y o1 ), Where S m S n Given the coordinates of the known silver wire point, r1 is the radius of the circle containing the theoretical silver wire.

[0084] Calculate the angle α between the given silver wire point and the center of the circle. i ,as follows:

[0085]

[0086] There are K-1 silver wire points between silver wire points m and n, and K is calculated by the following formula:

[0087]

[0088] Round() is the rounding function.

[0089] The coordinates of the kth undetermined silver thread point are S. k =(x k y k This can be obtained by solving the following equation:

[0090]

[0091] α k This represents the angle between the line connecting the k-th silver wire point and the known silver wire point m to the center of the circle.

[0092] In the case where the number of silver wire points i=1, the center O2 of the end face of the medicine column is taken as the center of the silver wire, and the position coordinates of the missing silver wire on the end face are calculated by interpolation.

[0093] When i=1, the coordinates S of the kth silver wire missing from the end face are calculated by interpolation. k =(x k y k The calculation algorithm is as follows:

[0094]

[0095] Where r1 is the radius of the circle containing the theoretical silver wire, and S L Given the coordinates of the silver wire point, α k Let be the angle between the k-th silver wire point and the line connecting the known silver wire point to the center of the circle.

[0096] The implementation methods described in this manual are interconnected and cannot be implemented independently of any single step. For details on the differences and similarities between each implementation method, please refer to the manual section. Regarding the implementation process, which mainly focuses on the drilling and shaping of silver wire holes on the end face of the propellant grain in solid rocket motors, the applied image acquisition and image feature processing algorithms are already well-established. Therefore, the innovation of this manual lies in its silver wire point recognition algorithm under incomplete information.

[0097] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, extensions, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

[0098] The parts of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A method for visually identifying and locating the position of silver wires covering the propellant grains in a solid rocket motor, characterized in that, include: Images of silver wires on the end face of the coated drug column were acquired and Gaussian filtered. Extract the Region of Interest (ROI) from the silver wire image on the end face of the coated drug column; Identify the white dots on the silver wires in the image of the coated drug column end face; The image of the silver wires on the end face of the coated drug column was puffed. A non-complete information silver wire point recognition algorithm was used to obtain the coordinate image of all silver wires. The actuator moves according to the silver wire coordinate system; Drilling and shaping of the end face of the coated propellant column; The incomplete information silver wire point recognition algorithm includes: performing silver wire point recognition for working conditions with a silver wire point count of 3≤i≤5 and for working conditions with a silver wire point count of i≤2 respectively; For working conditions where the number of silver wires is 3≤i≤5, silver wire identification is performed, including: calculating the center position of the silver wire on the end face using the least squares method, and calculating the coordinates of the missing silver wire on the end face using the interpolation method; Silver wire point identification is performed for the working condition where the number of silver wire points i≤2, including: after identifying the center of the end face of the drug column, silver wire point identification is performed for the two working conditions where the number of silver wire points i=2 and the number of silver wire points i=1 respectively.

2. The method for visually identifying and locating the position of silver wires covering the propellant grain in a solid rocket motor according to claim 1, characterized in that: Images of the silver wires on the end face of the coated drug cartridge were captured using a close-up industrial camera.

3. The method for visually identifying and locating the position of silver wires covering the propellant grain in a solid rocket motor according to claim 1, characterized in that: Wavelet transform was used to extract features of the ROI region of the silver wire on the end face of the drug column.

4. The method for visually identifying and locating the position of silver wires covering the propellant grain in a solid rocket motor according to claim 1, characterized in that: The process of expanding the image of the silver wire on the end face of the coated drug column further includes removing defective points from the image of the silver wire on the end face of the coated drug column.

5. The method for visually identifying and locating the position of silver wires covering the propellant grain in a solid rocket motor according to claim 1, characterized in that: For the condition where the number of silver wire points i=2, silver wire point identification is performed, including: The coordinates of the silver wire points are used to calculate the positions of the two silver wire centers. The coordinates of the center of the end face of the medicine column are used to eliminate the incorrect silver wire centers and obtain the correct silver wire center positions. The coordinates of the missing silver wire positions on the end face are obtained by interpolation. For the condition where the number of silver wire points i=1, silver wire point identification is performed, including: Using the center of the end face of the medicine column as the center of the silver wire, the coordinates of the missing silver wire on the end face are calculated by interpolation.

6. The method for visually identifying and locating the position of silver wires covering the propellant grain in a solid rocket motor according to claim 1, characterized in that: The position of the center of the silver wire on the end face is calculated using the least squares method. p The model is as follows: ， in, , These are the coordinates of the identifiable silver wires. , These are the coordinates of the center of the silver wire. .

7. The method for visually identifying and locating the position of silver wires covering the propellant grain in a solid rocket motor according to claim 1, characterized in that: The calculation of the coordinates of the missing silver wire position on the end face using interpolation includes: If the number of identified silver wire points i satisfies 3 ≤ i ≤ 5, then calculate , in, , The coordinates of the known silver thread points are given below. The coordinates of the center of the silver wire; This represents the angle between the line connecting the known silver wire points m and n and the center of the circle; if Then there are K-1 silver wire points between silver wire point m and silver wire point n, and K is calculated by the following formula: ; Round() is the floor function; The coordinates of the kth undetermined silver thread point are: We obtain the following by solving the equation: ， Where r is the radius of the fitted circle of the silver wire point; This represents the angle between the line connecting the k-th silver wire point and the known silver wire point m to the center of the circle.

8. The method for visually identifying and locating the position of silver wires covering the propellant grain in a solid rocket motor according to claim 7, characterized in that: When the number of silver wire points i=2, the calculation of the coordinates of the missing silver wires on the end face using interpolation includes: Calculate the coordinates of the center of the silver wire , ,in , Given the coordinates of the known silver wire point, r1 is the radius of the circle containing the theoretical silver wire; Calculate the angle between the given silver wire point and the line connecting the center of the circle. : ， There are K-1 silver wire points between silver wire point m and silver wire point n, and K is calculated by the following formula: ; The coordinates of the kth undetermined silver thread point are: We obtain the following by solving the equation: ， This represents the angle between the line connecting the k-th silver wire point and the known silver wire point m to the center of the circle.

9. The method for visually identifying and locating the position of silver wires covering the propellant grain in a solid rocket motor according to claim 8, characterized in that: When the number of silver wire points i=1, the step of calculating the coordinates of the missing silver wire position on the end face using interpolation includes: The coordinates of the k-th silver wire missing from the end face are calculated using interpolation. The calculation formula is as follows: ， Where r1 is the radius of the circle containing the theoretical silver wire. Given the coordinates of the silver thread point, Let be the angle between the k-th silver wire point and the line connecting the known silver wire point to the center of the circle.

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