Ablation boundary layer space measurement position dynamic identification and tracking method

Abstract

The application provides an ablative boundary layer space measurement position dynamic identification and tracking method, which comprises the following steps: (1) arranging an ablative boundary layer optical dynamic measurement system; (2) collecting ablative boundary layer emission spectrum information of a heatproof material through the ablative boundary layer optical dynamic measurement system, and determining main radiation components and wavelengths in the ablative boundary layer of the heatproof material through analysis of the obtained emission spectrum information; (3) collecting radiation images of the heatproof material and a flow field around the heatproof material through the ablative boundary layer optical dynamic measurement system, reading and processing each frame of radiation images in real time to obtain ablative boundary layer position change information of the heatproof material, and then dynamically measuring parameters of a required space position in the ablative boundary layer in real time, so as to finally realize the ablative boundary layer space measurement position dynamic identification and tracking. The application has reasonable design, can accurately analyze the gas-solid coupling effect in the boundary layer, and is suitable for popularization and application.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hypersonic vehicle aerodynamic heat protection technology, and particularly relates to a method for dynamically identifying and tracking the measurement position of an ablation boundary layer. BACKGROUND

[0002] Hypersonic vehicles face extreme thermal environments when flying in the atmosphere, and at this time the thermal protection system plays a key protective role. The thermal protection material not only needs to withstand high temperatures, but also needs to cope with complex chemical reactions such as catalysis, oxidation and ablation in the boundary layer of interaction with the surrounding high-enthalpy non-equilibrium gas. These processes become more complex due to gas-solid coupling effects. For this reason, non-invasive diagnostic methods based on optics, such as tunable diode laser absorption spectroscopy (TDLAS), optical emission spectroscopy (OES), laser-induced fluorescence (LIF), etc., can measure key parameters without disturbing the flow field, which helps to analyze the coupling mechanism of multiple processes in the boundary layer, and provides important scientific basis and reference for the development of vehicle thermal protection technology.

[0003] S. Fang et al. explored the gas-solid coupling interface evolution of C / C heat-resistant materials in high-enthalpy non-equilibrium flow through optical diagnostic technology (Spectral insight into the interface evolution of a carbon / carbon composite under high-enthalpy, nonequilibrium flow). The translational temperature and number density of O atoms were measured at different axial positions (0, 1, 2 mm) on the surface of the material using TDLAS. The results show that there are obvious differences in the measurement results at these positions, indicating that there are fine chemical reaction regions in the boundary layer on the surface of the heat-resistant material. Therefore, it is necessary to measure the parameters at different spatial positions to reflect the interaction mechanism in the boundary layer. However, a large number of related studies, including S. Fang, indicate that the heat-resistant material will undergo ablation deformation during thermal testing, causing the surface to expand or recede, and thus driving the ablation boundary layer to move. The original measurement point may not accurately reflect the actual boundary layer parameters. Therefore, it is necessary to develop a method that can dynamically track the ablation boundary layer to accurately characterize the gas-solid coupling effect in the boundary layer.

[0004] Since the ablative boundary layer appears at the reaction site of the material surface and the incoming flow, tracking the material surface position is an effective way to identify the dynamic changes of the ablative boundary layer. Image processing technology provides a solution for this, as shown in Fagnani's work (3D infrared temperature maps measurements of ablative materials during plasma wind tunnel experiments), which uses imaging combined with edge detection and three-dimensional reconstruction and other image processing methods to track the ablative behavior of heat-resistant materials during the experiment. However, it is worth noting that this method still faces challenges when applied to heat-resistant material thermal evaluation experiments: the blurring of the image caused by strong radiation increases the difficulty of data processing; determining the range of the ablative boundary layer is challenging; and most image processing methods only support offline analysis, which cannot achieve real-time monitoring and adjustment.

[0005] In summary, the existing heat-resistant material boundary layer parameter measurement method based on optical means cannot cope with the dynamic changes of the ablative boundary layer, so it is necessary to further innovate the existing technology. SUMMARY

[0006] In view of the technical problems in the above background art, the present application provides a method for dynamically identifying and tracking the spatial measurement position of the ablative boundary layer, which has a reasonable concept and can accurately analyze the gas-solid coupling effect in the boundary layer, overcoming the problem that the existing optical means cannot adapt to the dynamic changes of the ablative boundary layer when measuring the boundary layer parameters of heat-resistant materials.

[0007] To solve the above technical problems, the present application provides a method for dynamically identifying and tracking the spatial measurement position of the ablative boundary layer, which includes the following steps:

[0008] (1) First, lay out an ablative boundary layer optical dynamic measurement system for ablative boundary layer spatial measurement position dynamic identification and tracking;

[0009] (2) Then, collect the emission spectrum information of the ablative boundary layer of the heat-resistant material through the ablative boundary layer optical dynamic measurement system laid out in step (1), and determine the main radiation components and wavelengths in the ablative boundary layer of the heat-resistant material by analyzing the obtained emission spectrum information;

[0010] (3) Then, collect the radiation images of the heat-resistant material and its surrounding flow field through the ablative boundary layer optical dynamic measurement system laid out in step (1), read and process each frame of radiation image in real time to obtain the ablative boundary layer position change information of the heat-resistant material, then dynamically measure the parameters of the required spatial position in the ablative boundary layer in real time, and finally realize the dynamic identification and tracking of the spatial measurement position of the ablative boundary layer.

[0011] The method for dynamically identifying and tracking the space measurement position of the ablation boundary layer, wherein: the optical dynamic measurement system of the ablation boundary layer in step (1) comprises a plasma device, a linear servo motor displacement table, an optical measurement device, a computer, a high-speed camera and a filter;

[0012] The plasma device is used to provide high-enthalpy plasma flow;

[0013] The heat protection material is installed in the test cabin of the plasma device and aligned with the center of the plasma jet nozzle for simulating the thermal environment of a hypersonic aircraft in flight;

[0014] The linear servo motor displacement table is matched and arranged outside the plasma device;

[0015] The optical measurement device is matched and installed on the linear servo motor displacement table, and the position of the optical measurement device is adjusted synchronously by the computer controlling the linear servo motor displacement table, for measuring the parameters of the required space position in the ablation boundary layer;

[0016] The filter is matched and installed in front of the lens of the high-speed camera, for collecting high-frame-rate high-resolution radiation images of the selected waveband of the filter;

[0017] The computer is located outside the plasma device and connected with the linear servo motor displacement table and the high-speed camera respectively; the computer receives the radiation images collected by the high-speed camera, processes the collected radiation images to obtain the position change information of the ablation boundary layer of the heat protection material, and feeds back to the linear servo motor displacement table.

[0018] The method for dynamically identifying and tracking the space measurement position of the ablation boundary layer, wherein: for TDLAS measurement, the optical measurement device comprises a TDLAS transmitting end and a TDLAS receiving end, and the linear servo motor displacement tables are matched and arranged outside the plasma devices located on the opposite sides of the heat protection material; the TDLAS transmitting end and the TDLAS receiving end are matched and installed on the linear servo motor displacement tables located on the opposite sides of the heat protection material.

[0019] The method for dynamically identifying and tracking the space measurement position of the ablation boundary layer, wherein: for OES measurement, the optical measurement device only comprises an OES receiving end, and the linear servo motor displacement table is matched and installed outside the plasma device located on one side of the heat protection material; the OES receiving end is matched and installed on the linear servo motor displacement table located on one side of the heat protection material.

[0020] The ablation boundary layer space measurement position dynamic identification and tracking method, wherein: for LIF measurement, the optical measurement device only contains an LIF emission end, and a linear servo motor displacement table is matched and installed on the outer side of the plasma device on the side of the heat protection material; the LIF emission end is matched and installed on the linear servo motor displacement table on the side of the heat protection material.

[0021] The ablation boundary layer space measurement position dynamic identification and tracking method, wherein: the step (2) is to collect the emission spectrum information of the heat protection material ablation boundary layer by using the spectrometer, then draw the emission spectrum line based on the obtained emission spectrum information, and then according to the emission spectrum line and the chemical element composition of the experimental environment, query the publicly used spectrum database to find the elements corresponding to each peak in the spectrum line, that is, the main radiation components of the ablation boundary layer of the heat protection material used.

[0022] The ablation boundary layer space measurement position dynamic identification and tracking method, wherein: the step (3) is to select and install the corresponding filter in front of the lens of the high-speed camera according to the radiation components and their wavelengths that appear throughout the ablation of the heat protection material and have appropriate radiation intensity, so as to effectively filter out the radiation interference caused by the flow around the heat protection material, make the surface profile of the heat protection material clear and visible, confirm the area where the ablation boundary layer is located, and finally continuously collect the radiation images of the heat protection material and its surrounding flow field by the high-speed camera installed with the filter.

[0023] The ablation boundary layer space measurement position dynamic identification and tracking method, wherein: in the step (3), the computer reads each frame of radiation image in real time, identifies the position of the heat protection material surface in the radiation image by using an edge detection algorithm, compares the results of the current frame with those of the previous frame, obtains the displacement change of the heat protection material surface position, and obtains the ablation boundary layer position change information of the heat protection material.

[0024] The ablation boundary layer space measurement position dynamic identification and tracking method, wherein: the specific process of identifying the position of the heat protection material surface in the radiation image by using the edge detection algorithm is as follows: first, based on the characteristics that the flow field radiation is stronger than the heat protection material radiation in the radiation image, and there is a clear intensity gradient between the two, the Sobel edge detection method is used to obtain the edges in the image where there is a clear gradient, then the boundary tracking algorithm is used to obtain all the boundaries of the detected edges, further exclude the chaotic non-material edges, and finally identify the actual surface position.

[0025] The ablation boundary layer space measurement position dynamic identification and tracking method, wherein: in the step (3), the computer converts the obtained ablation boundary layer position change information of the heat protection material into a displacement signal and feeds back to the linear servo motor displacement table, the linear servo motor displacement table drives the optical measurement equipment to move a corresponding displacement amount, so as to realize the synchronous adjustment of the position of the optical measurement equipment, and then the optical measurement equipment after the synchronous adjustment is used to realize the real-time dynamic measurement of the required space position parameters in the ablation boundary layer.

[0026] By adopting the technical scheme, the present application has the following beneficial effects:

[0027] The ablation boundary layer space measurement position dynamic identification and tracking method has reasonable conception, can accurately analyze the gas-solid coupling effect in the boundary layer, and overcomes the problem that the existing optical means is difficult to adapt to the dynamic change of the ablation boundary layer when measuring the boundary layer parameters of the heat protection material.

[0028] Based on the different characteristics of different heat protection materials in the reaction in the aerodynamic heat test, the present application selects a suitable filter according to the boundary layer spectrum information and installs it in front of the high-speed camera to shoot the radiation image, can confirm the area of the ablation boundary layer in the experiment, effectively filters out the radiation interference brought by the flow around the heat protection material, makes the surface profile of the heat protection material clear and visible, reduces the time and complexity of image processing, and reduces the calculation error.

[0029] The present application can adapt to the movement change of the material ablation boundary layer in the heat protection material aerodynamic heat test, especially in the ablation deformation of the heat protection material, synchronously adjusts the optical measurement equipment, can more accurately obtain the ablation boundary layer parameters, and is helpful for analyzing the multi-process coupling mechanism in the boundary layer. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed in the following specific embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0031] Figure 1 The structural principle diagram of the ablation boundary layer optical dynamic measurement system laid in the embodiment of the present application;

[0032] Figure 2 The surface emission spectrum schematic diagram of the C / SiC heat protection material collected in the embodiment of the present application;

[0033] Figure 3The radiation image of the heat protection material in the high-enthalpy plasma flow directly collected by the high-speed camera and the 388nm CN radiation image with the filter in the embodiment of the present application;

[0034] Figure 4 The edge schematic diagram in which the obvious intensity gradient appears in the radiation image obtained by using the Sobel edge detection method in the embodiment of the present application;

[0035] Figure 5 The surface position schematic diagram of the heat protection material finally calculated in the embodiment of the present application;

[0036] Figure 6 The surface displacement schematic diagram of the C / SiC material calculated in the embodiment of the present application. DETAILED DESCRIPTION

[0037] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0038] The present application will be further explained and described below with reference to specific embodiments.

[0039] As shown in the figure, the method for dynamically identifying and tracking the measurement position of the ablation boundary layer space provided by the embodiment comprises the following steps: Figure 1 S100, first, the ablation boundary layer optical dynamic measurement system for dynamically identifying and tracking the measurement position of the ablation boundary layer space is laid out;

[0040] S200, then, the emission spectrum information of the heat protection material ablation boundary layer is collected by the laid-out ablation boundary layer optical dynamic measurement system, and the main radiation components and wavelengths in the ablation boundary layer of the used heat protection material are determined by analyzing the obtained emission spectrum information.

[0041] S300, then, the radiation image of the heat protection material and the flow field around the heat protection material is collected by the laid-out ablation boundary layer optical dynamic measurement system, the position change information of the heat protection material ablation boundary layer in each frame of image is read and processed in real time, the parameters of the required space position in the ablation boundary layer are dynamically measured in real time, so as to realize the dynamic identification and tracking of the measurement position of the ablation boundary layer space.

[0042] In the embodiment of the present application, the ablation boundary layer optical dynamic measurement system is laid out

[0043] Figure 1 ​The ablation boundary layer optical dynamic measurement system is used to realize dynamic identification and tracking of the spatial measurement position of the ablation boundary layer; wherein the ablation boundary layer optical dynamic measurement system comprises a plasma device, a linear servo motor displacement table, an optical measurement device, a computer, a high-speed camera and a filter; wherein, Figure 1 The plasma device (top view) shows the positional relationship between the optical measurement device and the plasma device, and the plasma device (bottom view) shows the positional relationship between the high-speed camera and the plasma device.

[0044] The plasma device is used to provide high-enthalpy plasma flow; wherein the plasma device is composed of an ICP generator, a supersonic nozzle, a test cabin and a vacuum system; the left and right sides of the test cabin are matched with optical windows for the optical measurement device to measure, and the top is provided with an optical window for the high-speed camera to shoot.

[0045] The heat protection material is installed in the test cabin of the plasma device and aligned with the center of the plasma ejection nozzle, which is used to simulate the thermal environment of the hypersonic aircraft in flight.

[0046] The optical measurement device is installed on the linear servo motor displacement table, and the position of the optical measurement device can be adjusted by the computer controlling the linear servo motor displacement table, which is used to measure the parameters of the required spatial position in the ablation boundary layer.

[0047] The lens of the high-speed camera is matched with a filter, which is used to collect high-frame-rate high-resolution radiation images of the selected waveband of the filter.

[0048] The computer is located outside the plasma device, which is connected with the linear servo motor displacement table and the high-speed camera respectively, used to receive the radiation images collected by the high-speed camera, process the radiation images to obtain the position change information of the heat protection material ablation boundary layer and feedback to the linear servo motor displacement table.

[0049] Further, the above step S300 is based on the radiation components and their wavelengths that appear throughout the ablation of the heat protection material and have appropriate radiation intensity as the reference, selects the corresponding filter and installs it in front of the lens of the high-speed camera, effectively filters out the radiation interference brought by the flow around the heat protection material, makes the surface profile of the heat protection material clear and visible, confirms the area where the ablation boundary layer is located, and finally continuously collects the radiation images of the heat protection material and its surrounding flow field by the high-speed camera installed with the filter. Wherein, selecting appropriate filter for radiation image acquisition can reduce the influence of strong radiation flow on image processing.

[0050] In step S300 above, the computer converts the acquired information on the position change of the ablation boundary layer of the heat-resistant material into a displacement signal and feeds it back to the linear servo motor displacement stage. The linear servo motor displacement stage drives the optical measuring device to move the corresponding displacement, thereby realizing the synchronous adjustment of the position of the optical measuring device. Then, the synchronously adjusted optical measuring device realizes the real-time dynamic measurement of the required spatial position parameters within the ablation boundary layer.

[0051] In this embodiment, a typical C / SiC heat-resistant material is used for dynamic identification and tracking of the spatial measurement position of the ablation boundary layer, and TDLAS is used for parameter measurement. Therefore, the optical measurement device includes a TDLAS transmitter and a TDLAS receiver, which are respectively installed on both sides of the C / SiC heat-resistant material.

[0052] In this embodiment, the spectrometer measures the spectral information of the C / SiC material surface, and the resulting emission spectrum is shown below. Figure 2 As shown, there is significant CN radiation in the 385nm-388nm range, especially at 388nm where the CN radiation intensity is moderate and persists throughout the entire material ablation process. Therefore, this embodiment uses a 388nm filter specifically designed for CN radiation. As for the O and N radiation appearing in the 700nm to 900nm range, since they originate from the flow field itself and are present almost throughout the entire flow field, their ability to distinguish the flow around it is limited. Furthermore, this wavelength range is more susceptible to interference from blackbody radiation, so it was not considered.

[0053] Furthermore, it should be noted that different heat-resistant materials undergo different reactions in high-enthalpy currents, resulting in different characteristic components that characterize their boundary layers. For ease of explanation, this embodiment selects C / SiC heat-resistant material as the measurement object. If other heat-resistant materials are used, such as C / C, SiC, or C / SiC-ZrB2, their main radiative components in the ablation boundary layer will differ, and correspondingly, the required filters will also be different.

[0054] In this embodiment, a high-speed camera equipped with a 388nm filter continuously acquires radiation images of the heat-resistant material and its surrounding flow field, and each frame of the image is read and processed by a computer in real time.

[0055] Furthermore, a frame of radiation image of the high-enthalpy plasma flow in the heat-resistant material, acquired using a high-speed camera equipped with a 388nm filter, is shown below. Figure 3 The grayscale image on the right is shown; compare it with... Figure 3A comparison of radiation images acquired under the same operating conditions without a filter on the left side clearly shows that the former, by capturing the radiation of CN, the main component on the surface of the heat-resistant material, can accurately indicate the location of the ablation boundary layer, while effectively shielding the radiation interference generated by the surrounding flow. This makes the outline of the heat-resistant material surface clearer, forming a sharp contrast with the radiation of the surrounding flow field, thereby simplifying the subsequent image processing workflow, shortening the processing time, and reducing complexity.

[0056] Furthermore, the acquired image is processed using an edge detection algorithm. In this embodiment, the edge detection algorithm is used to further process the image. Figure 3 The following is an example of image processing using a specific frame of CN radiation image. Firstly, based on the characteristic that the flow field radiation is stronger than the heat-resistant material radiation in the radiation image, and there is a significant intensity gradient between the two, the Sobel edge detection method is used to obtain edges in the image where a clear gradient appears. The detection results are shown below. Figure 4 As shown. Ideally, the identified material edge should be Figure 4 The long vertical line on the left corresponds to the material surface, but because there is also a certain intensity gradient at the edge of the CN radiation field, therefore... Figure 4 A rather messy vertical line appeared on the right side of the surface of the model being inspected.

[0057] The Sobel edge detection method described above utilizes the Sobel operator. The image is convolved to obtain gradient images in the horizontal and vertical directions, and then the gradients in the two directions are merged to obtain a gradient magnitude image. Next, a threshold is set, and pixels with gradient magnitudes greater than the threshold are identified as edge points, generating a binary edge image, thus obtaining the edge of the image.

[0058] Furthermore, a boundary tracking algorithm is used to obtain all boundaries of the detected edges. Based on the characteristic that the edges of the material surface are clear and distinct, and the detected boundaries are more continuous, messy non-material edges are further eliminated (specifically, starting from a certain pixel of the detected edge, searching for its surrounding 8 pixels in a clockwise direction to find the first edge point, then using this point as the center, continuing to search for its surrounding 8 pixels in a clockwise direction, repeating this process until returning to the starting point or there are no more points around it, finally obtaining all the boundaries of the edges obtained by Sobel edge detection, with the longest boundary being the material surface), ultimately identifying the actual surface location; the results are as follows. Figure 5 As shown by the thick white solid line, it can be seen that the surface of the heat-resistant material model detected and identified by the edge detection algorithm matches the actual image.

[0059] In the embodiment, each frame of radiation image is read and processed by a computer in real time, the surface of the heat protection material is identified by the edge detection algorithm, the result of the current frame is compared with that of the previous frame, the displacement change of the surface position of the heat protection material is obtained, and the position change information of the ablation boundary layer of the heat protection material is obtained.

[0060] Further, the calculated position change information of the ablation boundary layer of the heat protection material is immediately fed back to the linear servo motor displacement table provided with a TDLAS transmitting end and a receiving end, the TDLAS transmitting end and the receiving end are driven to move by the linear servo motor displacement table, the optical measurement position is adjusted synchronously according to the position change information of the boundary layer, and thus the dynamic identification and tracking of the space measurement position of the ablation boundary layer are realized.

[0061] Further, in the embodiment, the high-speed camera is set to have a collection frame rate of 5 fps, the image processing time of each frame is about 0.1 s, and the reaction time of the linear servo motor is very small and can be ignored. Therefore, the total image processing time is less than 0.2 s under the collection frame rate of 5 fps, and the requirement of processing each frame of image is met. The calculated surface displacement of the C / SiC material is shown in FIG. 6, and the forward movement of the material surface is positive. Figure 6 The specific calculation process is as follows: the surface position of the heat protection material in the image is detected by the foregoing method, the detection position result of the current frame is subtracted from that of the previous frame, the surface displacement of the heat protection material at the current time can be obtained, and each frame of image is processed in this way, and the real-time surface displacement of the heat protection material can be obtained. Figure 6 That is, the material surface displacement calculated in the embodiment.

[0062] For OES measurement, the optical measurement device only includes an OES receiving end, and a linear servo motor displacement table is matched and installed outside the plasma device located on one side of the heat protection material; the OES receiving end is matched and installed on the linear servo motor displacement table located on one side of the heat protection material.

[0063] For LIF measurement, the optical measurement device only includes an LIF transmitting end, and a linear servo motor displacement table is matched and installed outside the plasma device located on one side of the heat protection material; the LIF transmitting end is matched and installed on the linear servo motor displacement table located on one side of the heat protection material.

[0064] The present application has reasonable design, can accurately analyze the gas-solid coupling effect in the boundary layer, and overcomes the problem that the existing optical means is difficult to adapt to the dynamic change of the ablation boundary layer when measuring the boundary layer parameters of the heat protection material.

[0065] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for dynamic identification and tracking of the spatial measurement location of an ablation boundary layer, characterized in that, Includes the following steps: (1) First, deploy an optical dynamic measurement system for the ablation boundary layer for dynamic identification and tracking of spatial measurement positions; The ablation boundary layer optical dynamic measurement system in step (1) includes a plasma device, a linear servo motor displacement stage, an optical measurement device, a computer, a high-speed camera, and a filter. The plasma device is used to provide a high-enthalpy plasma flow. The heat-resistant material is installed in the test chamber of the plasma device and aligned with the center of the nozzle from which the plasma is ejected, in order to simulate the thermal environment of a hypersonic aircraft. The linear servo motor displacement stage is matched and installed on the outside of the plasma device. The optical measuring device is mounted on the linear servo motor displacement stage. The position of the optical measuring device is synchronously adjusted by the computer controlling the linear servo motor displacement stage, in order to measure the parameters of the required spatial position within the ablation boundary layer. The filter is fitted in front of the lens of the high-speed camera to acquire high frame rate, high resolution radiation images of the band selected by the filter. The computer is located outside the plasma device and is connected to the linear servo motor displacement stage and the high-speed camera respectively. The computer receives the radiation images acquired by the high-speed camera, processes the acquired radiation images to obtain the position change information of the ablation boundary layer of the heat-resistant material, and feeds it back to the linear servo motor displacement stage. (2) Then, the emission spectrum information of the ablation boundary layer of the heat-resistant material is collected by the optical dynamic measurement system of the ablation boundary layer set up in step (1), and the radiation composition and wavelength of the ablation boundary layer of the heat-resistant material are determined by analyzing the obtained emission spectrum information. (3) Taking the radiation composition and wavelength of the ablation boundary layer of the heat-resistant material determined in step (2) as a reference, the radiation image of the heat-resistant material and its surrounding flow field is collected by the optical dynamic measurement system of the ablation boundary layer set up in step (1). Each frame of radiation image is read and processed in real time to obtain the position change information of the ablation boundary layer of the heat-resistant material. Then, the parameters of the required spatial position in the ablation boundary layer are measured in real time, and finally the dynamic identification and tracking of the spatial measurement position of the ablation boundary layer is realized.

2. The method for dynamic identification and tracking of spatial measurement positions of ablation boundary layers as described in claim 1, characterized in that: For TDLAS measurement, the optical measurement device includes a TDLAS transmitter and a TDLAS receiver, and the linear servo motor displacement stage is respectively matched and arranged on the outside of the plasma device located on opposite sides of the heat-resistant material; the TDLAS transmitter and the TDLAS receiver are respectively matched and installed on the linear servo motor displacement stage located on opposite sides of the heat-resistant material.

3. The method for dynamic identification and tracking of spatial measurement positions of ablation boundary layers as described in claim 1, characterized in that: For OES measurement, the optical measurement device includes only an OES receiver, and the linear servo motor displacement stage is matched and installed on the outside of the plasma device located on one side of the heat-resistant material; the OES receiver is matched and installed on the linear servo motor displacement stage located on one side of the heat-resistant material.

4. The method for dynamic identification and tracking of spatial measurement positions of ablation boundary layers as described in claim 1, characterized in that: For LIF measurement, the optical measurement device includes only the LIF transmitter, and the linear servo motor displacement stage is matched and installed on the outside of the plasma device located on the side of the heat-resistant material; the LIF transmitter is matched and installed on the linear servo motor displacement stage located on the side of the heat-resistant material.

5. The method for dynamic identification and tracking of spatial measurement positions of ablation boundary layers as described in claim 1, characterized in that: Step (2) involves using the spectrometer to collect the emission spectrum information of the ablation boundary layer of the heat-resistant material, then drawing the emission spectrum lines based on the acquired emission spectrum information, and then querying publicly available spectral databases according to the emission spectrum lines and the chemical element composition of the experimental environment to find the elements corresponding to each peak in the spectrum, which are the main radiative components of the ablation boundary layer of the heat-resistant material used.

6. The method for dynamic identification and tracking of spatial measurement positions of ablation boundary layers as described in claim 1, characterized in that: Step (3) involves selecting the corresponding filter and installing it in front of the lens of the high-speed camera based on the radiation components and wavelengths that appear throughout the ablation process of the heat-resistant material and have appropriate radiation intensity. This effectively filters out radiation interference caused by the surrounding flow around the heat-resistant material, making the surface outline of the heat-resistant material clearly visible, confirming the area where the ablation boundary layer is located, and finally continuously acquiring radiation images of the heat-resistant material and its surrounding flow field through the high-speed camera equipped with the filter.

7. The method for dynamic identification and tracking of spatial measurement positions of ablation boundary layers as described in claim 1, characterized in that: In step (3), the computer reads each frame of the radiation image in real time, uses the edge detection algorithm to identify the position of the heat-resistant material surface in the radiation image, compares the result of the current frame with the previous frame, and obtains the displacement change of the heat-resistant material surface position, which is the information on the change of the position of the heat-resistant material ablation boundary layer.

8. The method for dynamic identification and tracking of spatial measurement positions of ablation boundary layers as described in claim 7, characterized in that, The specific process of using the edge detection algorithm to identify the location of the heat-resistant material surface in the radiation image is as follows: First, based on the characteristic that the flow field radiation is stronger than the heat-resistant material radiation in the radiation image and there is a significant intensity gradient between the two, the Sobel edge detection method is used to obtain the edges in the image with obvious gradients. Then, the boundary tracking algorithm is used on the detected edges to obtain all boundaries, further eliminating messy non-material edges, and finally identifying the actual surface location.

9. The method for dynamic identification and tracking of spatial measurement positions of ablation boundary layers as described in claim 1, characterized in that: In step (3), the computer converts the acquired information on the position change of the ablation boundary layer of the heat-resistant material into a displacement signal and feeds it back to the linear servo motor displacement stage. The linear servo motor displacement stage drives the optical measurement device to move the corresponding displacement, thereby realizing the synchronous adjustment of the position of the optical measurement device. Then, the synchronously adjusted optical measurement device realizes the real-time dynamic measurement of the required spatial position parameters within the ablation boundary layer.

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