Solid rocket engine tail flame radiation imaging characteristic batch processing method

Abstract

The invention belongs to the technical field of solid rocket engines, and particularly relates to a solid rocket engine tail flame radiation imaging feature batch processing method. According to the solid rocket engine tail flame radiation imaging characteristic batch processing method provided by the invention, the radiation intensity of imaging can be displayed more efficiently, more accurately and more visually, batch processing of the solid rocket engine tail flame radiation imaging characteristics is realized, and the processing efficiency is improved. Abnormal points are eliminated in a sliding window and threshold mode, errors of radiation values are reduced, and calculation accuracy is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of solid rocket engines, and in particular relates to a method for batch processing radiation imaging features of tail flames of solid rocket engines. Background Art

[0002] The research on the radiation characteristics of the tail flame of solid rocket engines involves many fields, including flow field, temperature field, chemical reaction concentration field, particle concentration field, infrared radiation intensity field, etc. The research methods of infrared radiation intensity field include experimental measurement method, numerical simulation method, etc.

[0003] Based on the numerical simulation method, Du Weibiao and others obtained the solid rocket engine outlet parameters and external flow field parameters, calculated the solid particle density and temperature of multiple spatial points in the external flow field along the engine outlet axis; used the cubic spline function to interpolate the solid particle density and temperature of multiple spatial points in the external flow field, and obtained the density and temperature distribution of all solid particles in the external flow field; based on the density and temperature distribution of all solid particles in the external flow field, the radiation characteristics of all solid particles in the entire spatial area of ​​the external flow field were calculated, and finally the infrared radiation characteristic distribution of the tail flame of the solid rocket engine was determined. However, the accuracy of the numerical simulation results is closely related to the selected mathematical model and calculation method. For complex problems, a large amount of computing resources and computing time are required, and the interpretation of the simulation results is difficult.

[0004] Cao Yigang and others used computer fluid dynamics software simulation to obtain specific data of a certain type of missile for flow field parameters. The radiation parameters were calculated by calling the spectral line parameters in the HITRAN database using the line-by-line integration method. Both acquisition methods are relatively accurate at this stage, thus ensuring the accuracy of the source data. In addition, in terms of data processing, the three-dimensional data processing method is used to place the entire flow field data and target model into a three-dimensional scene. The flow field data in the line of sight direction is extracted using the concept of what you see is what you get, which improves the accuracy of data extraction and the efficiency of overall calculation. Compared with general methods, the processing is more flexible and more scalable. In addition, it can also solve the problem of determining the projection area of ​​the tail flame under the occlusion of complex models. After detailed processing of the radiation calculation data, the CG spectral band model method is used to solve the radiation transfer equation and obtain the radiation distribution along any observation direction. In the specific calculation, the radiation calculation in a certain direction is equivalent to the calculation of several parallel lines of sight. The idea of ​​block summation is used to consider the influence of different local areas on the whole, which increases the calculation precision, but leads to a significant increase in calculation complexity and calculation time.

[0005] Based on the experimental measurement method, Tao Ye and his colleagues obtained the radiation brightness image of the rocket engine tail flame, extracted the significant radiation area of ​​the tail flame, determined the overall radiation characteristics and geometric characteristics of the tail flame, and determined the corresponding image statistical characteristics based on the single-column images perpendicular to the development direction of the tail flame in the significant radiation area of ​​the tail flame; based on the obtained radiation characteristics and geometric characteristics of the overall tail flame and all image statistical characteristics, a high-dimensional feature vector for characterizing the rocket engine tail flame was obtained through feature splicing; the obtained high-dimensional feature vector was subjected to dimensionality reduction processing to obtain a reduced dimensionality feature vector; based on the obtained reduced dimensionality feature vector, rocket power target status monitoring was realized, but dimensionality reduction processing through high-dimensional images makes it difficult to retain image details, resulting in detail loss and reduced accuracy.

[0006] In view of the shortcomings of the above-mentioned solid rocket engine tail flame radiation imaging processing method, the present invention proposes a solid rocket engine tail flame radiation imaging feature batch processing method to solve the current processing method based on a single solid rocket engine tail flame radiation imaging feature, which is inefficient and time-consuming, and the existing method does not eliminate abnormal points, thereby resulting in large errors in some of the radiation values ​​obtained, which in turn affects the technical problems of calculation accuracy. Summary of the invention

[0007] The present invention proposes a batch processing method for tail flame radiation imaging features of a solid rocket engine. The tail flame radiation imaging processing method is more efficient, more accurate and more intuitive.

[0008] In order to achieve the above object, the present invention solves the above technical problems through the following technical solutions:

[0009] A method for batch processing of radiation imaging features of tail flames of solid rocket engines comprises the following steps:

[0010] S1: Acquire the radiation imaging data sequence of the tail flame of the solid rocket engine, and use the first data of the imaging data sequence as the radiation imaging data at the initial ignition moment;

[0011] S2: input the radiation imaging data at the initial ignition time;

[0012] S3: Outlier elimination through sliding window and threshold processing;

[0013] S4: calibrate the radiometric imaging data using the calibration equation;

[0014] S5: sequentially input the radiation imaging data sequence after the initial ignition moment, perform S3 and S4 steps on each input imaging data, and then calculate the radiation energy and display the hot map;

[0015] S6: The radiation imaging data in which the radiation energy is converted from a negative value to a positive value is used as the initial ignition moment again, and steps S2 to S5 are repeated to realize batch processing of data.

[0016] S7: Output the radiation energy and hot map corresponding to each radiation image.

[0017] The data sequence in S1 is obtained by using a special high-temperature infrared imaging camera to capture the radiation emitted by the tail flame of the solid rocket engine, and obtaining a thermal image data sequence generated by the camera.

[0018] The first data in the data sequence acquired by S1 is input as the radiation imaging data at the initial ignition moment.

[0019] The sliding window in S3 is performed on the pixel points of a single radiation image, and a fixed window size and a moving step length are defined. The window moves from one end of the image according to the step length until the entire image is covered. Outliers are eliminated in each window by using a set threshold, and the step length is the number of pixels that the window moves each time.

[0020] In S4, the calibration equation is in the form of: Y=aX+b, where a and b are coefficients obtained by calibrating the data acquisition device before the test, X is the original input radiation intensity value matrix, and Y is the calibrated radiation intensity value matrix.

[0021] The method for calculating the radiation energy in S5 is to calculate the radiation intensity difference between the input radiation imaging data and the pixel points corresponding to the imaging data at the initial ignition moment, and accumulate the difference to obtain the total radiation intensity at that moment.

[0022] The specific operation of the Hot map in S5 is to input the total radiation intensity matrix, use the rows and columns of the matrix as the x and y coordinates of the image, and map the radiation intensity value of each point in the matrix to the corresponding point of the image through color mapping, wherein the color mapping is to select the color mapping range according to the maximum and minimum values ​​of the radiation intensity in the matrix, each radiation brightness in the matrix corresponds to a specific color, and the color corresponding to each intensity in the matrix is ​​displayed in the image, so as to obtain the Hot map of the data.

[0023] Based on the implementation of the above technical solution, the present invention can achieve the following technical effects:

[0024] 1. The present invention provides a method for batch processing radiation imaging characteristics of tail flames of solid rocket engines, which can display the radiation intensity of imaging more efficiently, accurately and intuitively.

[0025] 2. The present invention provides a method for batch processing of radiation imaging features of the tail flame of a solid rocket engine, thereby realizing batch processing of radiation imaging features of the tail flame of a solid rocket engine and improving processing efficiency.

[0026] 3. The present invention provides a method for batch processing radiation imaging features of tail flames of solid rocket engines, which uses a sliding window and threshold method to eliminate abnormal points, reduce the error of radiation values, and improve calculation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a flow chart of the method for batch processing of engine tail flame radiation imaging characteristics provided by the present invention. DETAILED DESCRIPTION

[0029] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0030] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0031] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0032] In the embodiments of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0033] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0034] Combine the following Figure 1 A batch processing method for radiation imaging characteristics of tail flames of solid rocket engines provided by the present invention is introduced in detail:

[0035] Combination Figure 1 As shown, in an embodiment of the present invention, a method for batch processing of radiation imaging features of tail flames of solid rocket engines comprises the following steps:

[0036] S1: Obtain the radiation imaging data sequence of the tail flame of the solid rocket engine. Use a special high-temperature infrared imaging camera to capture the radiation emitted by the tail flame of the solid rocket engine, and obtain the thermal image data sequence generated by the camera. The thermal image data is a grayscale image, in which the brightness represents the radiation intensity. The first data of the data sequence is used as the radiation imaging data at the initial ignition moment to proceed to step S2.

[0037] S2: Input the radiation imaging data at the initial ignition moment, that is, the first data in the data sequence.

[0038] S3: Outliers are eliminated through sliding window and threshold processing. The sliding window is performed on the pixel points of a single radiation image. The size of a fixed window and the step length of movement are defined. The window moves from one end of the image according to the step length until the entire image is covered. Outliers are eliminated in each window through the set threshold, where the step length is the number of pixels the window moves each time.

[0039] The specific process is as follows: first define the window size and step size, start from the upper left corner of the image, place the window at the initial position of the image, slide the window from left to right with the set step size, and when the window reaches the right edge of the image, move the window down by one step size and slide it from left to right again. Repeat this process until the sliding window covers the entire image.

[0040] In addition, the operation of eliminating abnormal points in the window is as follows: after each window movement, the image area in the window is intercepted, and the abnormal points in the area are eliminated. The definition of an abnormal point is a pixel point whose radiation intensity value is greater than a certain specific value, and the specific value is the threshold. In the window, if there is a pixel point greater than the threshold, all the radiation intensities in the window are sorted, and the middle value is selected to replace the intensity value of the abnormal point. According to the overall size and data characteristics of the radiation imaging frame, different window sizes and step sizes can be selected, and different thresholds can be selected according to the radiation characteristics of the tail flame to eliminate abnormal points. In the present invention, the window size is set to 7X7 pixels, and the step size is equal to the window size, which is 7 pixels. The threshold is determined based on the radiation brightness value of the engine tail flame. The threshold at the initial ignition time in the present invention is 200W / (sr·m 2 ), the threshold for selecting the subsequent data sequence input is 2000W / (sr·m 2 ).

[0041] S4: Calibrate the radiation imaging data through the calibration equation. The calibration equation is in the form of: Y = aX + b, where a and b are coefficients obtained by calibrating the data acquisition equipment before the test, X is the original input radiation intensity value matrix, and Y is the calibrated radiation intensity value matrix.

[0042] S5: Input the radiation imaging data sequence after the initial ignition moment in sequence, perform S3 and S4 on each input imaging data, and then calculate the radiation energy and display the Hot map of the current imaging.

[0043] The specific method for calculating radiation energy is: calculate the radiation intensity difference between the input radiation imaging data and the corresponding pixel point of the imaging data at the initial ignition moment and add them up to obtain the total radiation intensity at that moment. The input radiation imaging data is taken as I2, and the radiation imaging at the initial ignition moment is taken as I1. The difference calculation formula is: I(x,y)=I2(x,y)-I1(x,y), where: (x,y) is the coordinate of a pixel in the imaging, I1(x,y) and I2(x,y) are the radiation intensity values ​​of the corresponding pixel points in the imaging I1 and I2, and I(x,y) is the radiation intensity of the difference image at the corresponding position. The sum of radiation energy is the accumulation of the current radiation difference and the previous radiation difference, and A(x,y)=A(x,y)+I(x,y), where (x,y) is the coordinate of a pixel in the imaging, A(x,y) and I(x,y) are the sum of the previous radiation intensity difference and the current radiation intensity difference.

[0044] The Hot map is used to intuitively display the radiation intensity corresponding to different times and imaging positions. The specific operation is: input the total radiation intensity matrix, use the rows and columns of the matrix as the rows and columns of the output image, and map the radiation intensity value of each point in the matrix to the corresponding point in the image through color. Among them, the color mapping is to select the color mapping range according to the maximum and minimum values ​​of the radiation intensity in the matrix. Each radiation brightness in the matrix corresponds to a specific color. The color corresponding to each intensity in the matrix is ​​displayed in the image to obtain the Hot map of the data.

[0045] S6: Use the radiation energy and the radiation imaging data that changes from a negative value to a positive value as the initial ignition moment, and repeat steps S2 to S5.

[0046] S7: Output the radiation energy and hot map corresponding to each radiation image.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for batch processing of radiation imaging features of tail flames of solid rocket engines, characterized in that: The following steps are involved: S1: Acquire the radiation imaging data sequence of the tail flame of the solid rocket engine, and use the first data of the imaging data sequence as the radiation imaging data at the initial ignition moment; S2: input the radiation imaging data at the initial ignition time; S3: Outlier elimination through sliding window and threshold processing; S4: calibrate the radiometric imaging data using the calibration equation; S5: sequentially input the radiation imaging data sequence after the initial ignition moment, perform S3 and S4 steps on each input imaging data, and then calculate the radiation energy and display the hot map; S6: The radiation imaging data in which the radiation energy is converted from a negative value to a positive value is used as the initial ignition moment again, and steps S2 to S5 are repeated to realize batch processing of data. S7: Output the radiation energy and hot map corresponding to each radiation image.

2. The method for batch processing of radiation imaging features of tail flames of solid rocket engines according to claim 1 is characterized in that: The data sequence in S1 is obtained by using a special high-temperature infrared imaging camera to capture the radiation emitted by the tail flame of the solid rocket engine, and obtaining a thermal image data sequence generated by the camera.

3. The method for batch processing of radiation imaging features of tail flames of solid rocket engines according to claim 2 is characterized in that: The first data in the data sequence acquired by S1 is input as the radiation imaging data at the initial ignition moment.

4. The method for batch processing of radiation imaging features of tail flames of solid rocket engines according to claim 3 is characterized in that: The sliding window in S3 is performed on the pixel points of a single radiation image, and a fixed window size and a moving step length are defined. The window moves from one end of the image according to the step length until the entire image is covered. Outliers are eliminated in each window by using a set threshold, and the step length is the number of pixels that the window moves each time.

5. The method for batch processing of radiation imaging features of tail flames of solid rocket engines according to claim 4 is characterized in that: In S4, the calibration equation is in the form of: Y=aX+b, where a and b are coefficients obtained by calibrating the data acquisition device before the test, X is the original input radiation intensity value matrix, and Y is the calibrated radiation intensity value matrix.

6. The method for batch processing of radiation imaging features of tail flames of solid rocket engines according to claim 5 is characterized in that: The method for calculating the radiation energy in S5 is to calculate the radiation intensity difference between the input radiation imaging data and the pixel points corresponding to the imaging data at the initial ignition moment, and accumulate the difference to obtain the total radiation intensity at that moment.

7. The method for batch processing of radiation imaging features of tail flames of solid rocket engines according to claim 6 is characterized in that: The specific operation of the Hot map in S5 is to input the total radiation intensity matrix, use the rows and columns of the matrix as the x and y coordinates of the image, and map the radiation intensity value of each point in the matrix to the corresponding point of the image through color mapping, wherein the color mapping is to select the color mapping range according to the maximum and minimum values ​​of the radiation intensity in the matrix, each radiation brightness in the matrix corresponds to a specific color, and the color corresponding to each intensity in the matrix is ​​displayed in the image, so as to obtain the Hot map of the data.

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