Pressure-sensitive paint pressure measuring method and system under variable component condition

Abstract

The invention discloses a pressure-sensitive paint pressure measurement method and system under a variable component condition, and solves the problem that when pressure measurement is carried out through pressure-sensitive paint, accurate pressure measurement is difficult in the prior art in a measurement area with continuously changing oxygen content. The change trend of the oxygen concentration at different positions is monitored in real time, and the oxygen concentration of each pixel point in the whole measurement range is subjected to partition reconstruction by using the oxygen concentration data at different positions, so that the change condition of the oxygen concentration of the whole field can be effectively obtained. In the initial calibration process, the pressure and the luminous intensity of the pressure-sensitive paint under different oxygen concentrations are calibrated, and the relational expression of the pressure, the oxygen concentration and the luminous intensity is obtained, so that the problem of large pressure measurement error of the pressure-sensitive paint under variable components can be effectively solved.

Description

Technical Field

[0001] The present invention relates to a pressure measurement method and system using pressure - sensitive paint, and more particularly to a pressure measurement method and system using pressure - sensitive paint under variable component conditions. Background Art

[0002] In the field of optical measurement technology, pressure - sensitive paint is an advanced measurement technology. Compared with traditional pressure sensors that can only obtain data through single - point measurement, this technology can obtain the pressure change trend of the entire measurement area, achieving a leap from point - to - surface pressure measurement. Moreover, pressure - sensitive paint is usually sprayed on the surface of the model, overcoming the interference of sensor installation on the flow field.

[0003] The pressure - sensitive paint technology is based on the principle of oxygen quenching, and reflects the pressure distribution on the model surface through the change in fluorescence intensity caused by the response of the luminescent probe to pressure. When not irradiated by laser, most of the luminescent molecules are in the ground state. After being irradiated by light, the luminescent molecules absorb energy and change from the ground state to the excited state. The luminescent molecules in the excited state are unstable and will release energy to return to the ground state. The energy is released in the form of light. When the luminescent molecules collide with the surrounding oxygen molecules, the oxygen molecules absorb the energy of the luminescent molecules and become excited, and the luminescent molecules lose energy and return to the ground state without generating light. The oxygen molecules reduce the light intensity released by the luminescent molecules in the whole process, and this process is called "oxygen quenching". Since the oxygen molecule content in the pressure - sensitive paint is related to the oxygen partial pressure, and the oxygen partial pressure is positively correlated with the local static pressure, the pressure on the surface of the pressure - sensitive paint can be obtained by quantitatively calculating the light intensity.

[0004] Currently, pressure - sensitive paint is mainly applied to the surface pressure measurement of models such as wings and turbine blades in large - scale fluid mechanics test devices such as wind tunnels and shock tubes, and is also involved in applications in outdoor open spaces. Usually, the components in the environment where the model sprayed with pressure - sensitive paint is located hardly change. In this case, the relationship between pressure and the light intensity of pressure - sensitive paint can be expressed by a calibrated formula. After obtaining the light intensity signals of the measurement area at different times through a high - speed camera, the pressure distribution and evolution process can be calculated according to the formula. However, in some cases, such as in a nitrogen - driven shock tube, the oxygen content in the measurement area changes over a period of time. At this time, the traditional calibration formula is no longer applicable. In this case, using a single calibration formula to calculate the pressure will bring great errors. Therefore, obtaining the change trend of oxygen concentration in different regions is crucial for the measurement results.

[0005] In December 2023, the Chinese invention with the publication number CN117249941A published "A Pressure Measurement Method for Multi-strand Non-uniform Density Gas Flow Field Based on Pressure Sensitive Paint". This method creates a fluid domain with a constant oxygen mole fraction by using an oxygen-containing mixed gas with a specific ratio of light, and realizes the surface pressure measurement of the multi-strand non-uniform density gas flow field. Although the gas density changes in this method, the oxygen content remains unchanged, and the measurement problem of pressure sensitive paint when the oxygen content changes is not solved.

[0006] In May 2022, the Chinese invention with the publication number CN114441090A published "A Method for Correcting Temperature Effect of Fast Response Pressure Sensitive Paint". This method corrects the temperature effect of test data and significantly improves the pressure measurement accuracy of fast response pressure sensitive paint. However, this method does not involve the correction problem under the change of oxygen concentration. Summary of the Invention

[0007] In order to solve the technical problem that it is difficult to accurately measure pressure in the prior art in the measurement area where the oxygen content is constantly changing when measuring pressure through pressure sensitive paint, the present invention provides a pressure measurement method and system for pressure sensitive paint under variable component conditions.

[0008] The inventive concept of the present invention:

[0009] A plurality of oxygen concentration sensors are uniformly arranged in the measurement area. By real-time monitoring the change trend of oxygen concentration at different positions, the oxygen concentration of each pixel point in the entire measurement range is reconstructed in different zones with the oxygen concentration data at different positions, and the change of the whole-field oxygen concentration can be effectively obtained. In the initial calibration process, the pressure and the luminescence intensity of the pressure sensitive paint under different oxygen concentrations are calibrated to obtain the relationship formula among pressure, oxygen concentration and luminescence intensity, and the problem of large pressure measurement error of the pressure sensitive paint under variable components can be effectively solved.

[0010] In order to achieve the above object and complete the above inventive concept, the present invention adopts the following technical solutions:

[0011] A pressure measurement method for pressure sensitive paint under variable component conditions, which is used for a planar rectangular model to be measured, is characterized in that it includes the following steps:

[0012] Step 1, calibrate the pressure of the pressure sensitive paint under constant light intensity and different oxygen concentrations to obtain the corresponding relationship among pressure, light intensity and oxygen concentration;

[0013] Step 2, spray the pressure sensitive paint on the surface of the model to be measured;

[0014] Step 3, set up an oxygen concentration sensor matrix on the surface of the model to be measured, establish a coordinate system, and obtain the coordinates of each oxygen concentration sensor;

[0015] Step 4: Place the model to be measured in the measurement area, and place a light source and a high-speed camera with the acting end facing the surface of the model to be measured in the measurement area, and trigger them synchronously.

[0016] Step 5: Obtain the spatio-temporal evolution data of the light intensity of the pressure-sensitive paint through the high-speed camera, and obtain the spatio-temporal evolution data of the oxygen concentration of the pressure-sensitive paint through the oxygen concentration sensor matrix and its coordinates.

[0017] Step 6: Calculate the spatio-temporal evolution data of the pressure of the pressure-sensitive paint on the surface of the model to be measured through the corresponding relationship calibrated in Step 1 and the spatio-temporal evolution data of the light intensity and the spatio-temporal evolution data of the oxygen concentration obtained in Step 5, and complete the pressure measurement of the pressure-sensitive paint under variable component conditions.

[0018] Further, Step 3 is specifically as follows:

[0019] Step 3: Virtually create a rectangular grid on the surface of the model to be measured, place oxygen concentration sensors at each cross point of the rectangular grid to form an oxygen concentration sensor matrix, establish a coordinate system with the longitudinal direction of the rectangular grid as the x-axis and the transverse direction as the y-axis, and obtain the coordinates of each oxygen concentration sensor. The x-axis and y-axis are respectively parallel to the two perpendicular sides of the model to be measured.

[0020] Further, Step 5 specifically includes:

[0021] 5.1: Obtain a sequence of images of the surface of the model to be measured through the high-speed camera, and extract the spatio-temporal evolution data of the light intensity from the sequence of images.

[0022] 5.2: Obtain the spatio-temporal evolution data of the oxygen concentration in the measurement area through each oxygen concentration sensor in the oxygen concentration sensor matrix.

[0023] Further, in Step 3, the coordinates of the four corners of the rectangular grid are respectively denoted as (x0, y0), (x0, y f ), (x g , y0), (x g , y f );

[0024] In the rectangular grid, a cell with an oxygen concentration sensor on its edge is denoted as the first sub-region. The first sub-region includes sub-regions R1, R2, R3, and R4 located at the four corners of the rectangular grid respectively; the coordinates of the oxygen concentration sensor included in sub-region R1 are denoted as (x1, y1); the coordinates of the oxygen concentration sensor included in sub-region R2 are denoted as (x1, y f-1 ); the coordinates of the oxygen concentration sensor included in sub-region R3 are denoted as (x g-1 , y1); the coordinates of the oxygen concentration sensor included in sub-region R4 are denoted as (x g-1 , y f-1 );

[0025] In the rectangular grid, the cells with two oxygen concentration sensors on their edges and located at the longitudinal edges of the rectangular grid are denoted as the second longitudinal sub-region, and the cells with two oxygen concentration sensors on their edges and located at the transverse edges of the rectangular grid are denoted as the second transverse sub-region;

[0026] In the rectangular grid, the cells with four oxygen concentration sensors on their edges are denoted as the third sub-region;

[0027] In step 5.2, the method for obtaining the spatio-temporal evolution data of the oxygen concentration in the measurement area is as follows:

[0028] For the first sub-region, the oxygen concentration w(x n , y m ) at the t k -th moment is: n , y m , t k ) is:

[0029]

[0030] where w(x1, y1, t k ) is the measured value of the oxygen concentration sensor with coordinates (x1, y1) in the sub-region R1 at the t k -th moment; w(x1, y f-1 , t k ) is the measured value of the oxygen concentration sensor with coordinates (x1, y k ) in the sub-region R2 at the t f-1 -th moment; w(x g-1 , y1, t k ) is the measured value of the oxygen concentration sensor with coordinates (x k , y1) in the sub-region R3 at the t g-1 -th moment; w(x g-1 , y f-1 , t k ) is the measured value of the oxygen concentration sensor with coordinates (x k , y g-1 , y f-1 ) in the sub-region R4 at the t

[0031] For the second longitudinal sub-region, the oxygen concentration w(x n , y m ) at the t k -th moment is: n , y m , t k ) is:

[0032]

[0033] where w(xi-1 , y1, t k ), at the t k -th moment, the measured value of the oxygen concentration sensor at the coordinate (x i-1 , y1) in the second longitudinal sub-region; w(x i , y1, t k ) is the measured value of the oxygen concentration sensor at the coordinate (x k , y1) in the second longitudinal sub-region at the t i -th moment; i ∈ (0, g);

[0034] For the second transverse sub-region, the oxygen concentration w(x n , y m ), t k ) at the t n -th moment is: m k j-1 ) is:

[0035]

[0036] where w(x1, y j-1 , t k ) is the measured value of the oxygen concentration sensor at the coordinate (x1, y k ) in the second transverse sub-region at the t j-1 -th moment; w(x1, y j , t k ) is the measured value of the oxygen concentration sensor at the coordinate (x1, y k ) in the second transverse sub-region at the t j -th moment; j ∈ (0, f);

[0037] For the third sub-region, the oxygen concentration w(x n , y m ), t k ) at the t n -th moment is: m k i-1 ) is:

[0038]

[0039] where w(x i-1 , y j-1 , t k ), w(x i-1 , y j , t k ), w(x i , y j-1 , t k ) and w(x i , y j , t k) are the measured values of the four oxygen concentration sensors in the third sub-region at the t-th moment respectively. The coordinates of the four oxygen concentration sensors are (x k , y i-1 ), (x j-1 , y i-1 ), (x j , y i ), and (x j-1 , y i ), (x j ).

[0040] Furthermore, step 4 specifically includes:

[0041] 4.1 Place the model to be measured in the measurement area, place a light source with its acting end facing the surface of the model to be measured and a high-speed camera in the measurement area, and connect a synchronizer and an oscilloscope to the high-speed camera and the oxygen concentration sensors respectively;

[0042] 4.2 Through pre-triggering, based on the time difference of the rising edges of the corresponding signals of the high-speed camera and each oxygen concentration sensor shown by the oscilloscope, adjust the delay time between each signal through the synchronizer to make them trigger synchronously.

[0043] A pressure-sensitive paint pressure measurement system under variable component conditions is used to implement the above-mentioned pressure-sensitive paint pressure measurement method under variable component conditions. The special feature is that it includes a light source, a high-speed camera, a computer, and multiple oxygen concentration sensors;

[0044] The light source is used to provide light intensity to the surface of the rectangular plane model to be measured sprayed with pressure-sensitive paint;

[0045] The high-speed camera is connected to the computer and is used to capture an image sequence of the surface of the model to be measured;

[0046] The multiple oxygen concentration sensors are arranged on the surface of the model to be measured in a matrix form and are respectively connected to the computer to obtain the oxygen concentration of the corresponding measurement area;

[0047] The computer is used to calculate the spatio-temporal evolution data of the pressure of the pressure-sensitive paint on the surface of the model to be measured through the image sequence and the oxygen concentration measured by each oxygen concentration sensor.

[0048] Furthermore, it also includes a synchronizer;

[0049] The synchronizer is respectively connected to the high-speed camera and each oxygen concentration sensor to ensure the time consistency of the data obtained by the oxygen concentration sensor and the high-speed camera.

[0050] Furthermore, it also includes an oscilloscope;

[0051] The input end of the oscilloscope is respectively connected to the high-speed camera and each oxygen concentration sensor, and its output end is connected to the computer.

[0052] Advantages of the present invention:

[0053] 1. A pressure measurement method using pressure-sensitive paint under variable component conditions provided by the present invention can effectively cope with the pressure measurement scenarios under unsteady oxygen content scenarios, especially the pressure measurement scenarios under component changes, and has a significant effect on solving the pressure measurement problems in wind tunnels and shock tubes.

[0054] 2. A pressure measurement method using pressure-sensitive paint under variable component conditions provided by the present invention combines high-speed camera images and oxygen sensor data, and has advantages such as simple operation and high processing efficiency.

[0055] 3. A pressure measurement method using pressure-sensitive paint under variable component conditions provided by the present invention combines the arrangement position and conditions of oxygen sensors, and selects different oxygen concentration reconstruction methods at different positions, and has advantages such as comprehensive consideration and high accuracy. Description of the Drawings

[0056] Figure 1 is a schematic structural diagram of an embodiment of a pressure measurement system using pressure-sensitive paint under variable component conditions of the present invention;

[0057] Figure 2 is a schematic structural diagram of arranging an oxygen concentration sensor matrix on the surface of a model to be measured in an embodiment of the present invention.

[0058] Reference Numerals in the Drawings:

[0059] 1 - Light source, 2 - High-speed camera, 3 - Computer, 4 - Oxygen concentration sensor, 5 - Model to be measured, 6 - Synchronizer, 7 - Oscilloscope. Detailed Embodiments

[0060] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0061] A pressure measurement system using pressure-sensitive paint under variable component conditions provided by an embodiment of the present invention is used for a planar rectangular model to be measured, as Figure 1 shown, and includes a light source 1, a high-speed camera 2, a computer 3, a synchronizer 6, an oscilloscope 7, and a plurality of oxygen concentration sensors 4.

[0062] The light source 1 is used to irradiate the surface of the rectangular plane test model 5 sprayed with the pressure-sensitive paint to excite the special luminescent material in the pressure-sensitive paint; the high-speed camera 2 is connected to the computer 3 and is used to capture the image sequence of the surface of the test model 5; multiple oxygen concentration sensors 4 are arranged on the surface of the test model 5 in a matrix form and are respectively connected to the computer 3 to obtain the oxygen concentration of the corresponding measurement area; the synchronizer 6 is respectively connected to the high-speed camera 2 and each oxygen concentration sensor 4 to ensure the time consistency of the data obtained by the oxygen concentration sensor 4 and the high-speed camera 2. The input end of the oscilloscope 7 is respectively connected to the high-speed camera 2 and each oxygen concentration sensor 4, and its output end is connected to the computer, and is used to record the signal history of the oxygen concentration sensor during the entire measurement process. The computer 3 is used to calculate the spatio-temporal evolution data of the pressure of the pressure-sensitive paint on the surface of the test model 5 through the image sequence and the oxygen concentration measured by each oxygen concentration sensor 4.

[0063] The pressure-sensitive paint pressure measurement is carried out using the above pressure measurement system, which specifically includes the following steps:

[0064] Step 1: Calibrate the pressure of the pressure-sensitive paint under constant light intensity and different oxygen concentrations to obtain the corresponding relationship between pressure, light intensity, and oxygen concentration;

[0065] Step 2: Spray the pressure-sensitive paint on the surface of the test model 5 and cure it;

[0066] Step 3: As Figure 2 shown, a virtual rectangular grid is formed on the surface of the test model 5, and oxygen concentration sensors 4 are respectively placed at the cross points of each rectangular grid to form an oxygen concentration sensor matrix. A coordinate system is established with the longitudinal direction of the rectangular grid as the x-axis and the transverse direction as the y-axis, and the coordinates of each oxygen concentration sensor 4 are obtained. The x-axis and y-axis are respectively parallel to the two perpendicular sides of the test model;

[0067] The coordinates of the four corners of the rectangular grid are respectively (x0, y0), (x0, y f ), (x g , y0), (x g , y f );

[0068] In the rectangular grid, the cell with an oxygen concentration sensor 4 on its edge is recorded as the first sub-region. The first sub-region includes sub-regions R1, R2, R3, and R4 located at the four corners of the rectangular grid respectively; the coordinates of the oxygen concentration sensor 4 included in the sub-region R1 are recorded as (x1, y1); the coordinates of the oxygen concentration sensor 4 included in the sub-region R2 are recorded as (x1, y f-1 ); the coordinates of the oxygen concentration sensor 4 included in the sub-region R3 are recorded as (x g-1 , y1); the coordinates of the oxygen concentration sensor 4 included in the sub-region R4 are recorded as (x g-1 , y f-1 );

[0069] In the rectangular grid, two oxygen concentration sensors 4 are provided on its edge, and the cells located at the longitudinal edge of the rectangular grid are denoted as the second longitudinal sub-region, and the cells located at the transverse edge of the rectangular grid with two oxygen concentration sensors 4 on its edge are denoted as the second transverse sub-region;

[0070] In the rectangular grid, the cells with four oxygen concentration sensors 4 on its edge are denoted as the third sub-region;

[0071] Step 4: Place the model 5 to be measured in the measurement area, and place the light source 1 and the high-speed camera 2 with the acting end facing the surface of the model 5 to be measured in the measurement area, and adjust the positions of the light source 1 and the high-speed camera 2 so that they can cover the entire measurement area more evenly; Start the light source 1, the high-speed camera 2 and each oxygen concentration sensor 4, and through pre-triggering, observe the time difference of the rising edges of the signals of the high-speed camera 2 and each oxygen concentration sensor 4 in the oscilloscope 7, and adjust the delay time between each signal through the synchronizer 6 to make them trigger synchronously to reduce the error of subsequent pressure reconstruction, and then start the measurement, and adjust the test parameters according to the test requirements.

[0072] Step 5: Obtain the spatio-temporal evolution data of the light intensity and the oxygen concentration;

[0073] 5.1. Obtain the sequence images of the surface of the model 5 to be measured through the high-speed camera 2, and extract the spatio-temporal evolution data of the light intensity from the sequence images;

[0074] 5.2. Obtain the spatio-temporal evolution data of the oxygen concentration in the measurement area through each oxygen concentration sensor 4, and the obtaining method is as follows:

[0075] For the first sub-region, the oxygen concentration w(x n , y m ) at the t k th moment is: n , y m , t k ) is:

[0076]

[0077] where w(x1, y1, t k ) is the measured value of the oxygen concentration sensor 4 with the coordinates (x1, y1) in the sub-region R1 at the t k th moment; w(x1, y f-1 , t k ) is the measured value of the oxygen concentration sensor 4 with the coordinates (x1, y k ) in the sub-region R2 at the t f-1 ) at the t g-1 , y1, t k ) is the measured value of the oxygen concentration sensor 4 with the coordinates (x kThe measured value of the oxygen concentration sensor 4 at the coordinates (x g-1 , y1) within the time-division region R3; w(x g-1 , y f-1 , t k ) is the measured value of the oxygen concentration sensor 4 at the coordinates (x g-1 , y f-1 ) within the time-division region R4 at the t k th moment;

[0078] For the second longitudinal sub-region, the oxygen concentration w(x n , y m ) at any coordinate point (x k , y n , y m , t k ) at the t

[0079]

[0080] th moment is: i-1 , y1, t k ) is the measured value of the oxygen concentration sensor 4 at the coordinates (x k , y1) within the second longitudinal sub-region at the t i-1 th moment; w(x i , y1, t k ) is the measured value of the oxygen concentration sensor 4 at the coordinates (x k , y1) within the second longitudinal sub-region at the t i th moment; i ∈ (0, g);

[0081] For the second transverse sub-region, the oxygen concentration w(x n , y m ) at any coordinate point (x k , y n , y m , t k ) at the t

[0082]

[0083] th moment is: j-1 , t k ) is the measured value of the oxygen concentration sensor 4 at the coordinates (x1, y k ) within the second transverse sub-region at the t j-1 th moment; w(x1, y j , t k ) is the measured value of the oxygen concentration sensor 4 at the coordinates (x1, y k ) within the second transverse sub-region at the t j th moment; j ∈ (0, f);

[0084] For the third sub-area, any coordinate point (x n ,y m ) k The oxygen concentration w(x n ,y m ,t k )for:

[0085]

[0086] Among them, w(x i-1 ,y j-1 ,t k )、w(x i-1 ,y j ,t k )、w(x i ,y j-1 ,t k ) and w(x i ,y j ,t k ) are respectively k The measured values of the four oxygen concentration sensors in the third sub-area at time t, the coordinates of the four oxygen concentration sensors are respectively (x i-1 ,y j-1 )、(x i-1 ,y j )、(x i ,y j-1 ) and (x i ,y j );

[0087] Step 6: Calculate the spatiotemporal evolution data of the pressure-sensitive paint pressure on the surface of the model 5 to be tested through the corresponding relationship calibrated in step 1 and the spatiotemporal evolution data of light intensity and oxygen concentration obtained in step 5, and complete the pressure measurement of the pressure-sensitive paint under variable component conditions.

[0088] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A pressure-sensitive paint pressure measurement method under variable component conditions, which is used for a planar rectangular model to be measured, and is characterized in that, It includes the following steps: Step 1: Calibrate the pressure of the pressure - sensitive paint under constant light intensity and different oxygen concentrations to obtain the corresponding relationship among pressure, light intensity, and oxygen concentration; Step 2: Spray the pressure - sensitive paint on the surface of the model to be measured (5); Step 3: Set up an oxygen - concentration sensor matrix on the surface of the model to be measured (5), establish a coordinate system, and obtain the coordinates of each oxygen - concentration sensor (4); Step 4: Place the model to be measured (5) in the measurement area, and place a light source (1) and a high - speed camera (2) with the acting end facing the surface of the model to be measured in the measurement area, and make them trigger synchronously; Step 5: Obtain the spatio - temporal evolution data of the light intensity of the pressure - sensitive paint through the high - speed camera (2), and obtain the spatio - temporal evolution data of the oxygen concentration of the pressure - sensitive paint through the oxygen - concentration sensor matrix and its coordinates; Step 6: Calculate the spatio - temporal evolution data of the pressure of the pressure - sensitive paint on the surface of the model to be measured (5) through the corresponding relationship calibrated in Step 1 and the spatio - temporal evolution data of the light intensity and oxygen concentration obtained in Step 5, and complete the pressure measurement of the pressure - sensitive paint under variable - component conditions.

2. The pressure-sensitive paint pressure measurement method under variable component conditions according to claim 1, characterized in that, Step 3 specifically is: Step 3: Virtually divide a rectangular grid on the surface of the model to be measured (5), place oxygen - concentration sensors (4) at each cross - point of the rectangular grid respectively to form an oxygen - concentration sensor matrix, establish a coordinate system with the longitudinal direction of the rectangular grid as the x - axis and the transverse direction as the y - axis, and obtain the coordinates of each oxygen - concentration sensor (4). The x - axis and y - axis are respectively parallel to two perpendicular sides of the model to be measured (5).

3. The pressure-sensitive paint pressure measurement method under variable component conditions according to claim 2, characterized in that Step 5 specifically includes: 5.1: Obtain a sequence of images on the surface of the model to be measured (5) through the high - speed camera (2), and extract the spatio - temporal evolution data of the light intensity from the sequence of images; 5.2: Obtain the spatio - temporal evolution data of the oxygen concentration in the measurement area through each oxygen - concentration sensor (4) in the oxygen - concentration sensor matrix.

4. According to the method for measuring the pressure of the pressure - sensitive paint under variable - component conditions as described in claim 3, characterized in that: In step 3, the coordinates of the four corners of the rectangular grid are denoted as (x0, y0), (x0, y f ), (x g , y0), (x g , y f ); In the rectangular grid, the cell with an oxygen concentration sensor (4) on its edge is denoted as the first sub-region. The first sub-region includes sub-regions R1, R2, R3, and R4 located at the four corners of the rectangular grid respectively; the coordinates of the oxygen concentration sensor included in sub-region R1 are denoted as (x1, y1); the coordinates of the oxygen concentration sensor (4) included in sub-region R2 are denoted as (x1, y f-1 ); the coordinates of the oxygen concentration sensor (4) included in sub-region R3 are denoted as (x g-1 , y1); the coordinates of the oxygen concentration sensor (4) included in sub-region R4 are denoted as (x g-1 , y f-1 ); In the rectangular grid, there are two oxygen - concentration sensors (4) on its edge, and the cell located at the longitudinal edge of the rectangular grid is denoted as the second longitudinal sub - region, and the cell located at the transverse edge of the rectangular grid with two oxygen - concentration sensors (4) on its edge is denoted as the second transverse sub - region; In the rectangular grid, the cell with four oxygen - concentration sensors (4) on its edge is denoted as the third sub - region; In Step 5.2, the method for obtaining the spatio - temporal evolution data of the oxygen concentration in the measurement area is as follows: For the first sub-region, the oxygen concentration w(x n , y m ) at the t k -th moment is given by: n , y m , t k ) is: where, w(x1, y1, t k ) is the measured value of the oxygen concentration sensor (4) with coordinates (x1, y1) in sub-region R1 at the t k -th moment; w(x1, y f-1 , t k ) is the measured value of the oxygen concentration sensor (4) with coordinates (x1, y k ) in sub-region R2 at the t f-1 -th moment; w(x g-1 , y1, t k ) is the measured value of the oxygen concentration sensor (4) with coordinates (x k , y1) in sub-region R3 at the t g-1 -th moment; w(x g-1 , y f-1 , t k ) is the measured value of the oxygen concentration sensor (4) with coordinates (x k , y g-1 ) in sub-region R4 at the t f-1 -th moment; For the second longitudinal sub-region, the oxygen concentration w(x n , y m ), at the t k -th moment is given by: w(x n , y m , t k ) = where w(x i-1 , y1, t k ) is the measured value of the oxygen concentration sensor (4) with coordinates (x k , y1) in the second longitudinal sub-region at the t i-1 -th moment; w(x i , y1, t k ) is the measured value of the oxygen concentration sensor (4) with coordinates (x k , y1) in the second longitudinal sub-region at the t i -th moment; i ∈ (0, g); For the second horizontal sub-region, the oxygen concentration w(x n , y m ) at the t k -th moment is given by: n , y m , t k ) is: where, w(x1, y j-1 , t k ) is the measured value of the oxygen concentration sensor (4) at the coordinates (x1, y k ) in the second transverse sub-region at the t j-1 -th moment; w(x1, y j , t k ) is the measured value of the oxygen concentration sensor (4) at the coordinates (x1, y k ) in the second transverse sub-region at the t j -th moment; j ∈ (0, f); For the third sub-region, the oxygen concentration w(x n , y m ) at the t k -th moment is given by: n , y m , t k ) is: Among them, w(x i-1 , y j-1 , t k ), w(x i-1 , y j , t k ), w(x i , y j-1 , t k ), and w(x i , y j , t k ) are the measured values of the four oxygen concentration sensors in the third sub-region at the t k moment respectively. The coordinates of the four oxygen concentration sensors are (x i-1 , y j-1 ), (x i-1 , y j ), (x i , y j-1 ), and (x i , y j ).

5. The pressure-sensitive paint pressure measurement method under variable component conditions according to claim 4, characterized in that Step 4 specifically includes: 4.1: Place the model to be measured (5) in the measurement area, and place a light source (1) and a high - speed camera (2) with the acting end facing the surface of the model to be measured in the measurement area, and connect a synchronizer (6) and an oscilloscope (7) to the high - speed camera (2) and the oxygen - concentration sensors (4) respectively; 4.2: Through pre - triggering, based on the time difference of the rising edges of the corresponding signals of the high - speed camera (2) and each oxygen - concentration sensor (4) shown on the oscilloscope (7), adjust the delay time between each signal through the synchronizer (6) to make them trigger synchronously.

6. A pressure-sensitive paint pressure measurement system under variable component conditions, which is used to implement the pressure-sensitive paint pressure measurement method under variable component conditions according to any one of claims 1-5, and is characterized in that: It includes a light source (1), a high - speed camera (2), a computer (3), and multiple oxygen - concentration sensors (4); The light source (1) is used to provide light intensity to the surface of the rectangular - plane model to be measured (5) sprayed with the pressure - sensitive paint; The high-speed camera (2) is connected to a computer (3) and is used to capture an image sequence of the surface of the model to be measured (5). The multiple oxygen concentration sensors (4) are arranged on the surface of the model to be measured (5) in a matrix form and are respectively connected to the computer (3), and are used to obtain the oxygen concentration of the corresponding measurement area. The computer (3) is used to calculate the spatio-temporal evolution data of the pressure-sensitive paint pressure on the surface of the model to be measured (5) through the image sequence and the oxygen concentration measured by each oxygen concentration sensor (4).

7. The pressure-sensitive paint pressure measurement system under variable component conditions according to claim 6, characterized in that: It further includes a synchronizer (6). The synchronizer (6) is respectively connected to the high-speed camera (2) and each oxygen concentration sensor (4), and is used to ensure the time consistency of the data obtained by the oxygen concentration sensor (4) and the high-speed camera (2).

8. The pressure-sensitive paint pressure measurement system under variable component conditions according to claim 6 or 7, characterized in that: It further includes an oscilloscope (7). The input ends of the oscilloscope (7) are respectively connected to the high-speed camera (2) and each oxygen concentration sensor (4), and its output end is connected to the computer.

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