Condensation air volume measuring method of high-speed train air conditioner and related equipment

Abstract

The invention relates to the technical field of air volume measurement, and provides a high-speed train air conditioner condensation air volume measurement method and related equipment.The method comprises the steps that an air field at an air inlet of a target high-speed train air conditioner is divided into multiple air field areas in the length direction of the target high-speed train, and multiple sets of flow field images of all the air field areas are obtained; taking the flow field images of the two wind field areas corresponding to the part of the overlapping area in the plane as a first flow field image and a second flow field image respectively, and obtaining an optimal matching line according to the first flow field image and the second flow field image; splicing the flow field images according to the optimal matching line to obtain a planar spliced flow field image; determining an effective flow field image area of the spliced flow field image based on the wind speed information in the spliced flow field image; and the condensation air volume information of the target high-speed train air conditioner is calculated according to the air speed information in the effective flow field image area. According to the method, the accuracy of condensation air volume measurement can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of air volume measurement, and in particular to a method for measuring the condensing air volume of a high-speed train air conditioner. Background Art

[0002] Many aerodynamic problems such as shear force, crosswind effect, intersection pressure wave and aerodynamic noise generated by the interaction between train and external airflow are particularly prominent. In response to these problems, scholars continue to conduct research and optimize train design to improve its wind resistance and operational stability. In this complex engineering field, the air conditioning system is also a key research direction as a core component to ensure passenger comfort. Its normal working state is directly related to the safety and comfort of high-speed trains.

[0003] During the operation of high-speed trains, the incoming airflow produces a large velocity gradient along the normal direction of the vehicle body, causing the high-speed airflow around the vehicle body to produce a strong shear force on the air conditioning unit on the roof, changing the air flow path and velocity distribution around it. At the same time, the changes in the internal / external pressure distribution of the air conditioning inlet and outlet caused by the high-speed airflow will deteriorate the performance of the fan, resulting in a significant decrease in the air volume in the air inlet area, which may trigger the shutdown protection mechanism. Relevant data show that compared with the bottom unit air conditioning unit, the roof unit air conditioning unit has a higher failure rate, especially after the high-speed train body design tends to be smooth, the thickness of the roof unit air conditioning is reduced, the internal air duct resistance is increased, and the decrease in condensation air volume is more significant. In addition, the increase in train running speed has also exacerbated the decrease in condensation air volume to a certain extent. Therefore, for the future speed-up process of high-speed trains and maglev trains, ensuring that the air conditioning system obtains sufficient condensation air volume to maintain normal operation is one of the key issues that need to be solved urgently.

[0004] Normally, the performance test of the on-board air conditioner before use can ensure that the various indicators of the fan meet the requirements. However, due to the speed-up process of the train and the installation location of the air inlet and outlet of the air conditioner, there are significant differences between the actual operating environment and the test environment. On the other hand, the pressure-sensitive characteristics of the condensing fan make it extremely susceptible to the ever-changing external environment, and the adjustment of the condensing air volume directly affects the heat dissipation efficiency of the air conditioning system. In view of this, ensuring that the condensing fan can accurately and promptly respond to changes in the external environment and adjust the condensing air volume to an appropriate level is an important measure to ensure the stable operation of the air conditioning system. Therefore, it is necessary to study the changing trend of the condensing air volume under the running state of the train, reveal the air inlet and outlet flow mechanism of the air conditioner, and provide support for the normal operation of the air conditioning system.

[0005] Although the train air conditioning condensing air volume can be obtained through numerical simulation methods, under the action of strong shear flow, the air conditioning grille and the high-speed rotating condensing fan will generate a large number of small-scale eddy structures. Conventional simulation methods are difficult to accurately capture these complex eddy characteristics at a limited computational cost. At the same time, the air volume is highly correlated with the wind speed, and the wind speed is extremely sensitive to the calculation accuracy of small-scale eddies. Any slight error in the simulation of the eddy structure will have a cumulative effect, which will significantly affect the accuracy of the air volume calculation results. Therefore, it is necessary to use experimental means to obtain the fluctuation range of the air conditioning condensing air volume under the action of strong shear flow to verify the simulation results and provide technical support for the heat dissipation optimization of the high-speed train air conditioning system.

[0006] At present, wind tunnel tests, dynamic model tests and real vehicle tests are usually used for aerodynamic characteristics tests of high-speed trains. Since the air-conditioning unit contains multiple small components and the local space is small, it is difficult for the scaled model test to effectively reproduce the flow field characteristics around the real fan. Therefore, the dynamic model and wind tunnel scaled test have great limitations in measuring the condensing air volume under the simulated train running state, and cannot meet the needs of accurate measurement. In the real vehicle test, there are two main methods for measuring the condensing air volume of the air-conditioning unit: one is static measurement, that is, the train is in a stationary state, and a flow hood is installed at the inlet / outlet of the air-conditioning condensing fan for measurement; the other is dynamic measurement, that is, the train is in a running state, and the local flow velocity is measured using a wind speed measuring instrument (such as a pitot tube, etc.), and then the condensing air volume is calculated by the integral method. In these two methods, the static measurement method ignores the influence of the aerodynamic effect when the train is running, and cannot truly reflect the change of air volume under the running state. In the dynamic real vehicle measurement, the wind speed sensor is prone to large errors under the action of strong shear flow, and may even cause distortion of the measurement results. It can be seen that the existing train air conditioning condensing air volume measurement method has the problem of low accuracy in condensing air volume measurement. Summary of the invention

[0007] The present application provides a condensing air volume measurement method and related equipment for a high-speed train air conditioner, which can solve the problem of low accuracy in condensing air volume measurement.

[0008] In a first aspect, an embodiment of the present application provides a method for measuring the condensing air volume of a high-speed train air conditioner, the condensing air volume measuring method comprising:

[0009] The wind field at the air inlet of the air conditioner of the target high-speed train is divided into multiple wind field areas along the length direction of the target high-speed train, and multiple groups of flow field images of all wind field areas are obtained; the multiple groups of flow field images correspond to multiple planes one by one, the planes are parallel to the length direction of the target high-speed train and perpendicular to the plane where the air inlet is located, each group of flow field images includes flow field images of all wind field areas in the same plane, there is an overlapping area between every two adjacent wind field areas, the flow field image is used to describe the wind speed information of the wind field area in the plane, and the wind speed information includes a two-dimensional streamwise velocity and a two-dimensional spanwise velocity;

[0010] For each portion of each overlapping area in each plane, the flow field images of the two wind field areas corresponding to the portion of the overlapping area in the plane are respectively used as the first flow field image and the second flow field image, and the best matching line is obtained according to the first flow field image and the second flow field image; the best matching line is used to splice the first flow field image and the second flow field image, and is a column of pixels in the second flow field image;

[0011] For each plane, all flow field images corresponding to the plane are spliced ​​according to all the best matching lines corresponding to the plane to obtain a spliced ​​flow field image of the plane;

[0012] For each stitched flow field image, determining the effective flow field image area of ​​the stitched flow field image based on the wind speed information in the stitched flow field image;

[0013] The condensing air volume information of the target high-speed train air conditioner is calculated based on the wind speed information in all valid flow field image areas; the condensing air volume information is used to describe the condensing air volume at a curved surface which is parallel to the plane where the air inlet of the target high-speed train air conditioner is located and the maximum distance between the curved surface and the plane is a preset distance.

[0014] Optionally, obtaining the best matching line according to the first flow field image and the second flow field image includes:

[0015] Taking each column of pixel points in the portion of the second flow field image corresponding to the overlapping area as a matching line;

[0016] For each matching line, a column of pixels in the first flow field image that overlaps with the matching line is used as a reference line, and a normalized root mean square error between the matching line and the reference line is calculated;

[0017] The matching line corresponding to the smallest normalized root mean square error is taken as the best matching line.

[0018] Optionally, calculate the normalized root mean square error between the matching line and the reference line, including:

[0019] The central pixel point of the reference line is used as the reference point, and multiple matching points are determined from all the pixel points of the matching line according to the reference point;

[0020] The normalized root mean square error between the matching line and the reference line is calculated based on all matching points.

[0021] Optionally, multiple matching points are determined from all pixel points of the matching line according to the reference point, including:

[0022] For all the pixels of the matching line, perform the following steps:

[0023] Determine whether the pixel meets Among them, u RP1 represents the two-dimensional flow velocity corresponding to the reference point, u MP1 represents the two-dimensional flow velocity corresponding to the pixel point, σ represents the matching tolerance, represents the average two-dimensional streamwise velocity corresponding to the reference line;

[0024] If yes, the pixel is taken as a matching point.

[0025] Optionally, the normalized root mean square error between the matching line and the reference line is calculated based on all matching points, including:

[0026] By formula:

[0027]

[0028] Calculate the normalized root mean square error NRMSE between the kth matching line and the kth reference line;

[0029] Among them, u LAk represents the two-dimensional flow velocity array of the k-th reference line, including the two-dimensional flow velocity of the pixel points corresponding to all matching points in the k-th reference line, u LBk represents the two-dimensional stream velocity array of the kth matching line, including the two-dimensional stream velocities of all matching points, v LAk represents the two-dimensional spanwise velocity array of the kth reference line, including the two-dimensional spanwise velocity of the pixel points corresponding to all matching points in the kth reference line, v LBk represents the two-dimensional spanwise velocity array of the kth matching line, including the two-dimensional spanwise velocities of all matching points, ||·|| F represents the Frobenius norm, k=1,2,...,K, and K represents the sequence number of the last matching line.

[0030] Optionally, all flow field images corresponding to the plane are spliced ​​according to all best matching lines corresponding to the plane to obtain a spliced ​​flow field image of the plane, including:

[0031] According to each best matching line, the first flow field image and the second flow field image corresponding to each best matching line are spliced ​​at the best matching line to obtain an initial spliced ​​flow field image of the plane;

[0032] For each best matching line, respectively, according to the wind speed information of the first flow field image and the wind speed information of the second flow field image corresponding to the best matching line, calculate the weighted wind speed information of multiple columns of pixels in the overlapping part between the first flow field image and the second flow field image corresponding to the best matching line;

[0033] The initial spliced ​​flow field image is smoothed according to all weighted wind speed information to obtain a planar spliced ​​flow field image.

[0034] Optionally, according to the wind speed information of the first flow field image and the wind speed information of the second flow field image corresponding to the best matching line, calculating the weighted wind speed information of multiple columns of pixels in the overlapping portion between the first flow field image and the second flow field image corresponding to the best matching line includes:

[0035] By formula:

[0036]

[0037] Calculate the weighted wind speed information u of the lth column of pixels in the overlapping part l and v l ;

[0038] Among them, u l represents the two-dimensional streamwise velocity array of the lth column of pixels, v l represents the two-dimensional spanwise velocity array of the lth column of pixels, b represents the number of the pixel column corresponding to the best matching line in the overlapping part, u LA represents the two-dimensional streamwise velocity array of a column of pixels corresponding to the best matching line in the first flow field image, u LB represents the two-dimensional streamwise velocity array of a column of pixels corresponding to the best matching line in the second flow field image, v LA represents the two-dimensional spanwise velocity array of a column of pixels corresponding to the best matching line in the first flow field image, v LB A two-dimensional spanwise velocity array representing a column of pixels corresponding to the best matching line in the second flow field image.

[0039] Optionally, determining a valid flow field image area of ​​the spliced ​​flow field image based on wind speed information in the spliced ​​flow field image includes:

[0040] By formula:

[0041]

[0042] Calculate the velocity gradient G of each pixel of the spliced ​​flow field image;

[0043] Wherein, U represents the sum of the two-dimensional streamwise velocity and the two-dimensional spanwise velocity in the spliced ​​flow field image, and y represents the vertical direction to the air inlet of the target high-speed train air conditioner;

[0044] The line composed of all pixels with a preset velocity gradient is taken as the contour line, and the spliced ​​flow field image is segmented using the contour line as the dividing line. The part of the segmentation result close to the plane where the air inlet of the target high-speed train air conditioner is located is taken as the effective flow field image area.

[0045] In a second aspect, an embodiment of the present application provides a condensing air volume measuring device for a high-speed train air conditioner, comprising:

[0046] an acquisition module, which divides the wind field at the air inlet of the air conditioner of the target high-speed train into multiple wind field areas along the length direction of the target high-speed train, and acquires multiple groups of flow field images of all wind field areas; the multiple groups of flow field images correspond to multiple planes one by one, the planes are parallel to the length direction of the target high-speed train and perpendicular to the plane where the air inlet is located, each group of flow field images includes flow field images of all wind field areas in the same plane, there is an overlapping area between every two adjacent wind field areas, and the flow field image is used to describe the wind speed information of the wind field area in the plane, and the wind speed information includes a two-dimensional streamwise speed and a two-dimensional spanwise speed;

[0047] The best matching line acquisition module is configured to respectively use the flow field images of the two wind field areas corresponding to the parts of each overlapping area in each plane as the first flow field image and the second flow field image, and acquire the best matching line according to the first flow field image and the second flow field image; the best matching line is used to splice the first flow field image and the second flow field image, and is a column of pixels in the second flow field image;

[0048] A stitching module stitches all flow field images corresponding to each plane according to all the best matching lines corresponding to the plane to obtain a stitched flow field image of the plane;

[0049] A determination module, for each stitched flow field image, determines a valid flow field image area of ​​the stitched flow field image based on wind speed information in the stitched flow field image;

[0050] A calculation module calculates the condensing air volume information of the target high-speed train air conditioner based on the wind speed information in all valid flow field image areas; the condensing air volume information is used to describe the condensing air volume at a curved surface which is parallel to the plane where the air inlet of the target high-speed train air conditioner is located and the maximum distance between the curved surface and the plane is a preset distance.

[0051] In a third aspect, an embodiment of the present application provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for measuring the condensing air volume of the high-speed train air conditioner when executing the above-mentioned computer program.

[0052] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, it implements the above-mentioned method for measuring the condensing air volume of the high-speed train air conditioner.

[0053] The above solution of the present application has the following beneficial effects:

[0054] In an embodiment of the present application, the wind field at the air inlet of the target high-speed train air conditioner is divided into multiple wind field areas along the length direction of the target high-speed train, and multiple groups of flow field images of all wind field areas are obtained, and then for each overlapping area in each plane, the flow field images of the two wind field areas corresponding to the overlapping area in the plane are respectively used as the first flow field image and the second flow field image, and the best matching line is obtained according to the first flow field image and the second flow field image, and then for each plane, all the flow field images corresponding to the plane are spliced ​​according to all the best matching lines corresponding to the plane to obtain a spliced ​​flow field image of the plane, and then for each spliced ​​flow field image, the effective flow field image area of ​​the spliced ​​flow field image is determined based on the wind speed information in the spliced ​​flow field image, and finally the condensing air volume information of the target high-speed train air conditioner is calculated according to the wind speed information in all the effective flow field image areas. Among them, the flow field image is used to describe the wind speed information at the air inlet of the air conditioner, and the wind speed data is converted into a two-dimensional image. There is no need to install an air volume detection instrument, and the wind speed data is not affected by the train speed, which improves the versatility and rationality of the air volume measurement. The best matching line is obtained and the flow field image is spliced ​​according to the best matching line, which can improve the accuracy of the speed information of the spliced ​​flow field image in the overlapping area. The air volume information is calculated based on the accurate spliced ​​flow field image, which can effectively improve the accuracy of the condensing air volume measurement.

[0055] In addition, the flow field information of a large area can be obtained by acquiring flow field images of multiple areas and then stitching them together, without being limited by the size of the data acquisition area.

[0056] Other beneficial effects of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0058] Figure 1 A flow chart of a method for measuring the condensing air volume of a high-speed train air conditioner provided in one embodiment of the present application;

[0059] Figure 2 A schematic diagram of a wind farm area provided in an embodiment of the present application;

[0060] Figure 3 A schematic diagram of a wind tunnel provided in an embodiment of the present application;

[0061] Figure 4 A schematic diagram of a wind tunnel terminal provided in an embodiment of the present application;

[0062] Figure 5 A schematic diagram of the structure of a measurement platform provided in one embodiment of the present application;

[0063] Figure 6 A schematic diagram of an air inlet and a wind field area provided in an embodiment of the present application;

[0064] Figure 7 A schematic diagram of a coordinate conversion process provided in an embodiment of the present application;

[0065] Figure 8 A schematic diagram of a best matching line provided by an embodiment of the present application;

[0066] Fig. 9 A schematic diagram of a spliced ​​flow field image provided in an embodiment of the present application;

[0067] Fig.10 A schematic diagram of a curved surface parallel to the air inlet provided in an embodiment of the present application;

[0068] Fig.11 A schematic diagram of two-dimensional spanwise velocity on a curved surface provided by an embodiment of the present application;

[0069] Fig.12 A schematic diagram of the structure of a condensing air volume measuring device for a high-speed train air conditioner provided in one embodiment of the present application;

[0070] Fig.13 A schematic diagram of the structure of a terminal device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0071] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0072] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0073] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0074] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0075] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0076] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0077] In response to the problem of low accuracy in existing condensing air volume measurement, an embodiment of the present application provides a condensing air volume measurement method for a high-speed train air conditioner. The air volume measurement method divides the wind field at the air inlet of the target high-speed train air conditioner into multiple wind field areas along the length direction of the target high-speed train, and obtains multiple groups of flow field images of all wind field areas, and then, for each overlapping area in each plane, the flow field images of the two wind field areas corresponding to the part of the overlapping area in the plane are respectively used as the first flow field image and the second flow field image, and the best matching line is obtained according to the first flow field image and the second flow field image, and then for each plane, all flow field images corresponding to the plane are spliced ​​according to all the best matching lines corresponding to the plane to obtain a spliced ​​flow field image of the plane, and then for each spliced ​​flow field image, the effective flow field image area of ​​the spliced ​​flow field image is determined based on the wind speed information in the spliced ​​flow field image, and finally, the condensing air volume information of the target high-speed train air conditioner is calculated according to the wind speed information in all the effective flow field image areas. Among them, the flow field image is used to describe the wind speed information at the air outlet of the air conditioner, and the wind speed data is converted into a two-dimensional image. There is no need to install an air volume detection instrument, and the wind speed data is not affected by the train speed, which improves the versatility and rationality of the air volume measurement. The best matching line is obtained and the flow field image is spliced ​​according to the best matching line, which can improve the accuracy of the speed information of the spliced ​​flow field image in the overlapping area. The air volume information is calculated based on the accurate spliced ​​flow field image, which can effectively improve the accuracy of the condensation air volume measurement.

[0078] In addition, the flow field information of a large area can be obtained by acquiring flow field images of multiple areas and then stitching them together, without being limited by the size of the data acquisition area.

[0079] Next, an exemplary description is given of the condensing air volume measurement method for high-speed train air conditioning provided in this application.

[0080] like Figure 1 As shown, the method for measuring the condensing air volume of a high-speed train air conditioner provided in the present application comprises the following steps:

[0081] Step 11, dividing the wind field at the air inlet of the air conditioner of the target high-speed train into multiple wind field areas along the length direction of the target high-speed train, and obtaining multiple groups of flow field images of all wind field areas.

[0082] The above-mentioned multiple groups of flow field images correspond to multiple planes one by one, the planes are parallel to the length direction of the target high-speed train and perpendicular to the plane where the air inlet is located, each plane intersects with multiple wind field areas, and the wind field areas are located outside the target high-speed train. Each group of flow field images includes flow field images of all wind field areas in the same plane, and there is an overlapping area between every two adjacent wind field areas. The flow field image is used to describe the wind speed information of the wind field area in the plane, and the wind speed information includes a two-dimensional flow velocity (the speed of the wind along the main direction on the two-dimensional plane, which is the speed along the direction parallel to the air inlet in this application) and a two-dimensional spanwise velocity (the speed of the wind along the main direction on the two-dimensional plane, which is the speed along the direction perpendicular to the air inlet in this application). The above-mentioned target high-speed train air conditioner is an air conditioner on a high-speed train that needs to measure wind speed. The flow field image can describe the wind speed information in the form of pixel values ​​(such as the pixel value of a pixel in the flow field image is the ratio of the two-dimensional flow velocity corresponding to the pixel to the two-dimensional spanwise velocity).

[0083] For example, the above-mentioned multiple wind farm areas are as follows: Figure 2 As shown, the wind field above the air inlet 1 and the air inlet 2 is divided into four wind field areas: wind field area A, wind field area B, wind field area C, and wind field area D, and adjacent wind field areas overlap with each other, and have overlapping areas, and the plane intersects with each wind field area.

[0084] In some embodiments of the present application, a full-scale train air-conditioning wind tunnel test platform can be established to obtain multiple sequentially connected wind field areas and multiple groups of flow field images of the target high-speed train air-conditioning.

[0085] Exemplarily, the full-scale train air conditioning wind tunnel test platform specifically includes a wind tunnel and a measurement platform:

[0086] Wind tunnel testing is an important research method in fluid mechanics. By studying the interaction between gas flow and air conditioning models, we can gain a deeper understanding of the aerodynamic characteristics of the air-conditioned area of ​​the train during operation. The essence of this method is based on the principle of similarity of motion to obtain an approximation of the actual operating state of the train. However, due to the strict requirements of wind tunnel tests on the size of the test object, the length of the test object must be less than the length of the test section and the blockage ratio must be less than 0.05. The typical width of a roof unit air conditioner is 2.0m, the height is 0.5m, and the cross-sectional area is 1.0m. 2 To meet the model blockage ratio of less than 0.05, the cross-sectional size of the wind tunnel needs to be at least 19.6m 2 There are few wind tunnel test platforms at home and abroad that can meet this size requirement, and larger wind tunnel test platforms consume extremely high energy. Therefore, this application conducts an open jet test while ensuring that the flow field uniformity test requirements are met by quickly and at low cost on a typical small space wind tunnel test platform, thereby ignoring the impact of model blockage on the comparison test.

[0087] When the outlet width of the wind tunnel expansion section is smaller than the width of the air conditioner itself, it is difficult to ensure the quality of the flow field by directly conducting the test, resulting in inconsistent flow velocity above the air conditioner inlet and outlet, and imbalance of environmental pressure in the area above the air conditioner inlet and outlet, which seriously interferes with the accuracy of the test results. In addition, the excessively large cross-sectional area of ​​the outer area of ​​the wind tunnel outlet causes the opening jet velocity to be too low, and it is impossible to simulate the actual situation of high-speed incoming flow. Therefore, it is considered to connect a section of wind tunnel duct to the end of the small space wind tunnel, compress it in height and expand it in width, so as to ensure the quality of the flow field in the air conditioner inlet and outlet area while increasing the incoming flow velocity as much as possible by reducing the cross-sectional area, such as Figure 3 As shown, the incoming flow enters the power section of the wind tunnel, and passes through the power section, the first test section, the second test section, the expansion section, and the grafting section to reach the test area at the exit.

[0088] Specific transformation methods such as Figure 4 As shown, Figure 4 a is an oblique view of the end of the wind tunnel. The end of the wind tunnel and the direction of the jet (i.e., the incoming flow) are parallel to the ground. Figure 4 b is a side view of the end of the wind tunnel, extending from the second test section to the wind tunnel exit. The original expansion section is modified together, keeping the same height as the second test section, and only expanding equally on both sides in the width direction. The expansion of the cross-sectional area of ​​the pipeline is changed from the original two-dimensional to one-dimensional, and it is directly connected from the high-speed section, and is only widened in the horizontal direction, which can better ensure that the uniform flow field structure of the high-speed section is less damaged.

[0089] Particle image velocimetry (PIV) is one of the non-contact velocity measurement technologies widely used in global flow field measurement at this stage, and is also an ideal velocity measurement tool for the air-conditioning air volume measurement wind tunnel test. However, due to the relatively large size of the air inlet and outlet of the air-conditioning condensing chamber, the length and width of the measurement area must be at least 590 mm. If the length of a single measurement area is controlled to be above 590 mm, it will not only reduce the spatial resolution of the measurement area, but also make the air outlet part located at the edge of the camera's viewing angle, resulting in a fisheye effect and greater distortion, both of which will have a direct impact on the measurement results. In addition, the maximum distance between the two air inlets has reached 1.29 m, which cannot be directly covered by PIV technology at this stage. And the synthetic analysis of the flow field of the two air inlets is very necessary for studying the problem of air intake under shear flow. Under comprehensive consideration, this application divides the flow field of the air inlet into multiple wind field areas to reduce the shooting area (i.e., wind field area) each time to improve the resolution.

[0090] The image acquisition and stitching method places strict requirements on the positional relationship between the laser and the camera, that is, to ensure that the distance from the laser plane to the camera remains unchanged and is within the depth of field of the camera. The most effective way is to refocus each shooting section, but this will also cause differences in the resolution of each set of images taken, increasing the difficulty of subsequent flow field stitching. In order to reduce the workload and ensure the measurement accuracy as much as possible, this application has built a PIV mobile measurement platform. The platform includes a two-dimensional mobile bracket on the top and a PIV measurement system composed of a low-frequency dual-pulse laser and a high-speed digital camera (CCD, Charge Coupled Device), such as Figure 5 As shown in FIG. 1 , the measurement platform includes a wind tunnel, a simulated train top, a laser, a pulse light source, and a CCD camera. The moving direction of the pulse light source in the platform is as follows: Figure 5 As shown by the double-headed arrows in the figure, the incoming flow direction is shown in the figure.

[0091] The wind field area is photographed using the full-scale train air conditioning wind tunnel test platform and measurement platform. The coordinate system and position definitions during the photography are as follows: Figure 6 As shown, the incoming flow direction is the positive direction of the x-axis, the height direction is the positive direction of the y-axis (i.e., the direction perpendicular to the air inlet of the air conditioner), and the z-axis direction is determined according to the right-hand rule. The origin of the coordinate system is located at the vertex of the upper surface of the air inlet 2 (AI2). Multiple two-dimensional planes of the xy axis are intercepted in the z-axis direction. For the x-direction, each air inlet is photographed twice to obtain the flow field image. The two air inlets are photographed four times in total. The shooting positions are defined as FOVA~FOV D along the incoming flow direction as a set of flow field images. In addition, a 20% overlap area is retained between each shooting area, that is, the area covered by the red dotted box in the figure. A total of 4 groups of images were taken for the two air inlets, each of which contained 55 sections (two-dimensional planes), and each section was photographed in 6 rounds of 720 images, totaling 158,400 images.

[0092] It should be noted that after acquiring the flow field images, the coordinates of all flow field images need to be converted to the same coordinates. Figure 6 Taking the embodiment shown as an example, the coordinate system of FOVA is used as the basic coordinate system, and the position coordinates of the same feature object are found in FOVA and FOV B. This process is based on feature boundary recognition. In this embodiment, the air inlet grille is used as the recognition feature. For example, the nth horizontal row (along the z-axis direction) of the grille of a certain inlet appears in the adjacent shooting area, that is, the relative translation distance of FOV B is determined according to the position of the horizontal row of grilles. The calculation formula of the relative translation distance is:

[0093] Dis X =ψ(X FOV A -X FOV B)

[0094] Dis Y =ψ(Y FOV A -Y FOV B )

[0095] Among them, Dis X and Dis Y Respectively represent the relative translation distance of FOV B in the x and y directions, positive and negative Figure 6 The direction of the coordinate system given in is consistent. (X FOV A -X FOV B ) is the difference in the horizontal coordinates of a fixed position in FOV A and FOV B, and (Y FOV A -Y FOV B ) is the difference in the vertical coordinates of a fixed position in FOV A and FOV B.

[0096] The coordinates of FOV A and FOV B are transformed according to the relative translation distance. The transformation process is as follows: Figure 7 As shown, Figure 7 The horizontal axis represents the x-coordinate, the vertical axis represents the y-coordinate, and the pixel value of the pixel point represents the corresponding wind speed information. Figure 7 a represents the original velocity field of FOVA (i.e. the original flow field image), Figure 7 b represents the flow field image after FOVA coordinate transformation, Figure 7 c is the flow field image after FOVA coordinate transformation with the overlapping area marked. Figure 7 d represents the original velocity field of FOV B (i.e. the original flow field image), Figure 7 e represents the flow field image after FOV B coordinate transformation, Figure 7 f is the flow field image after FOV B coordinate transformation with the overlapping area marked.

[0097] It is worth mentioning that the wind speed information at the air inlet of the air conditioner is described using flow field images, which realizes the conversion of wind speed data into a two-dimensional image. There is no need to install wind volume detection instruments, and the acquisition of wind speed data is not affected by the speed of the train, which improves the versatility and rationality of wind volume measurement.

[0098] Step 12: for each overlapping area in each plane, the flow field images of the two wind field areas corresponding to the overlapping area in the plane are respectively used as the first flow field image and the second flow field image, and the best matching line is obtained according to the first flow field image and the second flow field image.

[0099] The best matching line is used to splice the first flow field image and the second flow field image, and is a column of pixels in the second flow field image.

[0100] In some embodiments of the present application, the step of obtaining the best matching line according to the first flow field image and the second flow field image specifically includes:

[0101] In the first step, each column of pixel points in the portion of the second flow field image corresponding to the overlapping area is taken as a matching line.

[0102] In the second step, for each matching line, a column of pixels in the first flow field image that overlaps with the matching line is used as a reference line, and the normalized root mean square error between the matching line and the reference line is calculated.

[0103] First, the central pixel point of the reference line is used as the reference point, and multiple matching points are determined from all the pixel points of the matching line according to the reference point.

[0104] Specifically, for all pixel points of the matching line, perform the following steps:

[0105] Determine whether the pixel meets Among them, u RP1 represents the two-dimensional flow velocity corresponding to the reference point, u MP1 represents the two-dimensional flow velocity corresponding to the pixel point, σ represents the matching tolerance, represents the average 2D streamwise velocity corresponding to the reference line.

[0106] If yes, the pixel is taken as a matching point, otherwise, the pixel is not processed.

[0107] Then, the normalized root mean square error between the matching line and the reference line is calculated based on all matching points.

[0108] Specifically, through the formula:

[0109]

[0110] Calculate the normalized root mean square error NRMSE between the kth matching line and the kth reference line.

[0111] Among them, u LAk represents the two-dimensional flow velocity array of the k-th reference line, including the two-dimensional flow velocity of the pixel points corresponding to all matching points in the k-th reference line, u LBk represents the two-dimensional stream velocity array of the kth matching line, including the two-dimensional stream velocities of all matching points, v LAk represents the two-dimensional spanwise velocity array of the kth reference line, including the two-dimensional spanwise velocity of the pixel points corresponding to all matching points in the kth reference line, v LBk represents the two-dimensional spanwise velocity array of the kth matching line, including the two-dimensional spanwise velocities of all matching points, ||·|| Frepresents the Frobenius norm, k=1,2,...,K, and K represents the sequence number of the last matching line.

[0112] In the third step, the matching line corresponding to the normalized root mean square error with the smallest value is taken as the best matching line.

[0113] This step is illustrated below with reference to a specific example.

[0114] like Figure 8 As shown, in the overlapping parts of FOV A and FOV B, the rolling calculation starts from the first column of pixels (LA1 and LB1) in the edge area, and passes through the kth column of pixels (LAk and LBk). Each column of pixels determines n pixels as matching points, and calculates the normalized root mean square error until the last column of pixels (LAn and LBn), and the best matching line (LAb and LBb) is obtained according to the normalized root mean square error.

[0115] Step 13: for each plane, all flow field images corresponding to the plane are spliced ​​according to all best matching lines corresponding to the plane to obtain a spliced ​​flow field image of the plane.

[0116] In some embodiments of the present application, the above step of splicing all flow field images corresponding to the plane according to all the best matching lines corresponding to the plane to obtain the spliced ​​flow field image of the plane is specifically:

[0117] In the first step, according to each best matching line, the first flow field image and the second flow field image corresponding to each best matching line are spliced ​​at the best matching line to obtain an initial spliced ​​flow field image of the plane.

[0118] Specifically, the first flow field image and the second flow field image are segmented using the best matching line as the segmentation line, and only the image portion containing the non-overlapping portion in the decomposition result is retained, and then the two retained image portions are spliced ​​to obtain an initial spliced ​​flow field image.

[0119] In the second step, for each best matching line, weighted wind speed information of multiple columns of pixels in the overlapping part between the first flow field image and the second flow field image corresponding to the best matching line is calculated based on the wind speed information of the first flow field image and the wind speed information of the second flow field image corresponding to the best matching line.

[0120] Specifically, through the formula:

[0121]

[0122] Calculate the weighted wind speed information u of the lth column of pixels in the overlapping part l and v l .

[0123] Among them, u l represents the two-dimensional streamwise velocity array of the lth column of pixels, v l represents the two-dimensional spanwise velocity array of the lth column of pixels, b represents the number of the pixel column corresponding to the best matching line in the overlapping part, u LA represents the two-dimensional streamwise velocity array of a column of pixels corresponding to the best matching line in the first flow field image, u LB represents the two-dimensional streamwise velocity array of a column of pixels corresponding to the best matching line in the second flow field image, v LA represents the two-dimensional spanwise velocity array of a column of pixels corresponding to the best matching line in the first flow field image, v LB A two-dimensional spanwise velocity array representing a column of pixels corresponding to the best matching line in the second flow field image.

[0124] The third step is to smooth the initial spliced ​​flow field image according to all weighted wind speed information to obtain a planar spliced ​​flow field image.

[0125] Specifically, the pixel column corresponding to each weighted wind speed information in the initial spliced ​​flow field image is determined, and then the weighted wind speed information is used to replace the original wind speed information of the pixel column.

[0126] If the initial wind speed information of the first column of pixels, the second column of pixels, and the third column of pixels in the overlapping part is calculated in the above steps, the original wind speed information of the first column of pixels, the second column of pixels, and the third column of pixels in the initial spliced ​​flow field image is replaced with the corresponding weighted wind speed information.

[0127] It is worth mentioning that obtaining the best matching line and stitching the flow field images according to the best matching line can improve the accuracy of the velocity information of the stitched flow field images in the overlapping area.

[0128] The above steps are illustrated below with reference to a specific example.

[0129] like Fig. 9 As shown in FIG. 1 , the overlapping area of ​​FOV A and FOV B is subjected to FOV stitching based on weight distribution (i.e., this step), and a stitched flow field image of FOV A and FOV B is obtained, where the pixel value represents the ratio of the two-dimensional streamwise velocity to the two-dimensional spanwise velocity U / U ∞ .

[0130] Step 14: for each stitched flow field image, determine the effective flow field image area of ​​the stitched flow field image based on the wind speed information in the stitched flow field image.

[0131] In some embodiments of the present application, the step of determining the effective flow field image area of ​​the stitched flow field image based on the wind speed information in the stitched flow field image is specifically:

[0132] The first step is through the formula:

[0133]

[0134] Calculate the velocity gradient G of each pixel of the stitched flow field image.

[0135] Wherein, U represents the combined velocity of the two-dimensional streamwise velocity and the two-dimensional spanwise velocity in the spliced ​​flow field image, and y represents the vertical direction to the air inlet of the target high-speed train air conditioner.

[0136] It should be noted that G is a matrix, which includes the velocity gradient of each pixel of the spliced ​​flow field image.

[0137] In the second step, the line composed of all pixels with a preset velocity gradient is used as the contour line, and the stitched flow field image is segmented using the contour line as the dividing line. The part of the segmentation result close to the plane where the air inlet of the target high-speed train air conditioner is located is used as the effective flow field image area.

[0138] It should be noted that, if a column of pixels has multiple pixel points with speed gradients of preset values, only a pixel point on the plane closest to the air inlet of the target high-speed train air conditioner is taken; if a column of pixels does not have multiple pixel points with speed gradients of preset values, the pixel point corresponding to the center coordinates between the pixel with a speed gradient of the preset value before the pixel in the column and the pixel with a speed gradient of the preset value after the pixel in the column is taken.

[0139] For example, the preset value is 2s -1 , set the velocity gradient to 2s -1 The line composed of all pixels is taken as the contour line, and the spliced ​​flow field image is segmented into two parts according to the contour line, and only the part of the segmentation result close to the plane where the air inlet of the target high-speed train air conditioner is located is retained.

[0140] It is worth mentioning that due to the curved roof of the high-speed train, the reflection intensity of different sections affected by the curvature of the roof is not consistent. The change in reflection intensity directly affects the lower end position of the observable area photographed by PIV, resulting in the wind speed extraction process actually being extracted from the curved surface above the air inlet. This fluctuating lower bound of the observable area interferes with the results of the wind volume integral. In addition, the closer to the lower bound of the observable area, the greater the two-dimensional spanwise velocity, and the less interference the measurement results are caused by the shear flow. Therefore, determining the effective flow field image area can improve authenticity.

[0141] Step 15, calculating the condensing air volume information of the target high-speed train air conditioner based on the wind speed information in all effective flow field image areas.

[0142] The above condensing air volume information is used to describe the condensing air volume at a curved surface that is parallel to the plane where the air inlet of the target high-speed train air conditioner is located and the maximum distance between the curved surface and the plane is a preset distance. The curved surface is located outside the target high-speed train, and the preset distance is determined according to the distance between the boundary of the effective flow field image area and the plane where the air inlet is located.

[0143] Specifically, for the curved surface parallel to the air inlet, the wind speed information of the effective flow field image area of ​​all planes at the curved surface is integrated to obtain the air volume at the curved surface, and the expression is:

[0144] Q = ∫∫vds

[0145] Where Q represents the wind volume at the surface s, and v represents the two-dimensional spanwise velocity of all effective flow field image areas at the surface.

[0146] It should be noted that the above-mentioned curved surface s is determined according to the area of ​​the air inlet. For example, if the curved surface s is set to cover an area the same as the area of ​​the air inlet, the maximum distance between the curved surface s and the plane where the air inlet is located is a preset distance, such as 5 cm.

[0147] For example, the surface s is as follows: Fig.10 As shown in the figure, AI1 is air inlet 1, AI2 is air inlet 2, Flowdirection is flow direction, the surface with a downward arrow is the surface s for integration, and the curve on surface s is the intersection line of the surface and the plane where the effective flow field image area is located. All two-dimensional spanwise velocities at this surface are as follows Fig.11 As shown, Fig.11 The xz coordinate system is a two-dimensional coordinate system parallel to the air inlet, and the x-axis represents the coordinate value Lg x , the z-axis represents the coordinate value Lg z , the pixel value represents the negative value of the two-dimensional spanwise velocity -v, in meters per second (m / s), Fig.11 a is a schematic diagram of the two-dimensional spanwise velocity of AI2. Fig.11 b is a schematic diagram of the two-dimensional spanwise velocity of AI1.

[0148] It is worth mentioning that the wind speed information at the air inlet of the air conditioner is described using flow field images, which realizes the conversion of wind speed data into a two-dimensional image. There is no need to install wind volume detection instruments, and the wind speed data is not affected by the train speed, which improves the versatility and rationality of wind volume measurement. The best matching line is obtained and the flow field images are spliced ​​according to the best matching line, which can improve the accuracy of the speed information of the spliced ​​flow field images in the overlapping areas. The wind volume information is calculated based on the accurate spliced ​​flow field images, which can effectively improve the accuracy of wind volume measurement.

[0149] In addition, the method of this application has greatly improved the shortcomings of traditional test methods that can only study scaled models or can only statically measure full-size models. It has successfully measured the flow field results near the full-size air-conditioning area of ​​the high-speed train and corrected the calculation method of the air volume. By acquiring flow field images of multiple areas and then splicing them, it is not limited by the size of the data acquisition area and can obtain flow field information in a large area.

[0150] The following is an exemplary description of the condensing air volume measuring device for the high-speed train air conditioner provided in the present application.

[0151] like Fig.12 As shown, the embodiment of the present application provides a condensing air volume measuring device for a high-speed train air conditioner, and the condensing air volume measuring device 1200 for the high-speed train air conditioner includes:

[0152] Acquisition module 1201, divides the wind field at the air inlet of the air conditioner of the target high-speed train into multiple wind field areas along the length direction of the target high-speed train, and acquires multiple groups of flow field images of all wind field areas; the multiple groups of flow field images correspond to multiple planes one by one, the planes are parallel to the length direction of the target high-speed train and perpendicular to the plane where the air inlet is located, each group of flow field images includes flow field images of all wind field areas in the same plane, there is an overlapping area between every two adjacent wind field areas, the flow field image is used to describe the wind speed information of the wind field area in the plane, and the wind speed information includes a two-dimensional streamwise speed and a two-dimensional spanwise speed;

[0153] The best matching line acquisition module 1202, for each portion of each overlapping region in each plane, uses the flow field images of the two wind field regions corresponding to the portion of the overlapping region in the plane as the first flow field image and the second flow field image, respectively, and acquires the best matching line according to the first flow field image and the second flow field image; the best matching line is used to splice the first flow field image and the second flow field image, and is a column of pixels in the second flow field image;

[0154] The stitching module 1203 stitches all flow field images corresponding to each plane according to all best matching lines corresponding to the plane to obtain a stitched flow field image of the plane;

[0155] A determination module 1204 determines, for each stitched flow field image, a valid flow field image region of the stitched flow field image based on wind speed information in the stitched flow field image;

[0156] The calculation module 1205 calculates the condensing air volume information of the target high-speed train air conditioner based on the wind speed information in all valid flow field image areas; the condensing air volume information is used to describe the condensing air volume at a curved surface which is parallel to the plane where the air inlet of the target high-speed train air conditioner is located and the maximum distance between the curved surface and the plane is a preset distance.

[0157] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0158] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0159] like Fig.13 As shown, an embodiment of the present application provides a terminal device. The terminal device D10 of this embodiment includes: at least one processor D100 ( Fig.13 Only one processor is shown in the figure), a memory D101, and a computer program D102 stored in the memory D101 and executable on the at least one processor D100, wherein the processor D100 implements the steps of any of the above-mentioned method embodiments when executing the computer program D102.

[0160] Specifically, when the processor D100 executes the computer program D102, the wind field at the air inlet of the target high-speed train air conditioner is divided into multiple wind field areas along the length direction of the target high-speed train, and multiple groups of flow field images of all wind field areas are obtained, and then, for the part of each overlapping area in each plane, the flow field images of the two wind field areas corresponding to the part of the overlapping area in the plane are respectively used as the first flow field image and the second flow field image, and the best matching line is obtained according to the first flow field image and the second flow field image, and then for each plane, all the flow field images corresponding to the plane are spliced ​​according to all the best matching lines corresponding to the plane to obtain a spliced ​​flow field image of the plane, and then for each spliced ​​flow field image, the effective flow field image area of ​​the spliced ​​flow field image is determined based on the wind speed information in the spliced ​​flow field image, and finally, the condensing air volume information of the target high-speed train air conditioner is calculated according to the wind speed information in all the effective flow field image areas. Among them, the flow field image is used to describe the wind speed information at the air inlet of the air conditioner, and the wind speed data is converted into a two-dimensional image. There is no need to install an air volume detection instrument, and the wind speed data is not affected by the train speed, which improves the versatility and rationality of the air volume measurement. The best matching line is obtained and the flow field image is spliced ​​according to the best matching line, which can improve the accuracy of the speed information of the spliced ​​flow field image in the overlapping area. The air volume information is calculated based on the accurate spliced ​​flow field image, which can effectively improve the accuracy of the condensing air volume measurement.

[0161] In addition, the flow field information of a large area can be obtained by acquiring flow field images of multiple areas and then stitching them together, without being limited by the size of the data acquisition area.

[0162] The processor D100 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0163] In some embodiments, the memory D101 may be an internal storage unit of the terminal device D10, such as a hard disk or memory of the terminal device D10. In other embodiments, the memory D101 may also be an external storage device of the terminal device D10, such as a plug-in hard disk, a smart memory card (SMC, SmartMedia Card), a secure digital (SD, Secure Digital) card, a flash card (Flash Card), etc. equipped on the terminal device D10. Further, the memory D101 may also include both an internal storage unit of the terminal device D10 and an external storage device. The memory D101 is used to store an operating system, an application program, a boot loader (BootLoader), data and other programs, such as the program code of the computer program, etc. The memory D101 may also be used to temporarily store data that has been output or is to be output.

[0164] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0165] An embodiment of the present application provides a computer program product. When the computer program product runs on a terminal device, the terminal device can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0166] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, RandomAccess Memory), electric carrier signal, telecommunication signal and software distribution medium that can carry the computer program code to the condensing air volume measurement method device / terminal device of the high-speed train air conditioner. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0167] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0168] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0169] The above is a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles described in the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for measuring the condensing air volume of a high-speed train air conditioner, characterized in that: include: Divide the wind field at the air inlet of the air conditioner of the target high-speed train into multiple wind field areas along the length direction of the target high-speed train, and obtain multiple groups of flow field images of all wind field areas; Multiple groups of flow field images correspond to multiple planes one by one, the planes are parallel to the length direction of the target high-speed train and perpendicular to the plane where the air inlet is located, each group of flow field images includes flow field images of all wind field areas in the same plane, there is an overlapping area between every two adjacent wind field areas, the flow field image is used to describe the wind speed information of the wind field area in the plane, and the wind speed information includes a two-dimensional streamwise speed and a two-dimensional spanwise speed; For each portion of each overlapping area in each plane, the flow field images of the two wind field areas corresponding to the portion of the overlapping area in the plane are respectively used as the first flow field image and the second flow field image, and the best matching line is obtained according to the first flow field image and the second flow field image; the best matching line is used to splice the first flow field image and the second flow field image, and is a column of pixels in the second flow field image; For each of the planes, all flow field images corresponding to the plane are spliced ​​according to all best matching lines corresponding to the plane to obtain a spliced ​​flow field image of the plane; For each of the stitched flow field images, determining the effective flow field image area of ​​the stitched flow field image based on the wind speed information in the stitched flow field image; The condensing air volume information of the target high-speed train air conditioner is calculated based on the wind speed information in all valid flow field image areas; the condensing air volume information is used to describe the condensing air volume at a curved surface which is parallel to the plane where the air inlet of the target high-speed train air conditioner is located and the maximum distance between the curved surface and the plane is a preset distance.

2. The condensing air volume measurement method according to claim 1, characterized in that: The step of obtaining the best matching line according to the first flow field image and the second flow field image comprises: Taking each column of pixels in the portion of the second flow field image corresponding to the overlapping area as a matching line; For each matching line, a column of pixel points in the first flow field image that overlaps with the matching line is used as a reference line, and a normalized root mean square error between the matching line and the reference line is calculated; The matching line corresponding to the smallest normalized root mean square error is taken as the best matching line.

3. The condensing air volume measurement method according to claim 2, characterized in that: The calculating a normalized root mean square error between the matching line and the reference line includes: Taking the central pixel point of the reference line as a reference point, and determining a plurality of matching points from all the pixel points of the matching line according to the reference point; A normalized root mean square error between the matching line and the reference line is calculated according to all matching points.

4. The condensation air volume measurement method according to claim 3, characterized in that: Determining a plurality of matching points from all pixel points of the matching line according to the reference point includes: For all pixel points of the matching line, perform the following steps: Determine whether the pixel satisfies Among them, u RP1 represents the two-dimensional flow velocity corresponding to the reference point, u MP1 represents the two-dimensional flow velocity corresponding to the pixel point, σ represents the matching tolerance, represents the average two-dimensional streamwise velocity corresponding to the reference line; If so, the pixel point is taken as a matching point.

5. The condensation air volume measurement method according to claim 3, characterized in that: The calculating the normalized root mean square error between the matching line and the reference line according to all matching points includes: By formula: Calculate the normalized root mean square error NRMSE between the kth matching line and the kth reference line; Among them, u LAk represents the two-dimensional flow velocity array of the k-th reference line, including the two-dimensional flow velocity of the pixel points corresponding to all matching points in the k-th reference line, u LBk represents the two-dimensional flow velocity array of the kth matching line, including the two-dimensional flow velocities of all matching points, v LAk represents the two-dimensional spanwise velocity array of the k-th reference line, including the two-dimensional spanwise velocities of the pixel points corresponding to all matching points in the k-th reference line, v LBk represents the two-dimensional spanwise velocity array of the k-th matching line, including the two-dimensional spanwise velocities of all matching points, ||·|| F represents the Frobenius norm, k=1,2,...,K, and K represents the sequence number of the last matching line.

6. The condensing air volume measurement method according to claim 1, characterized in that: The step of splicing all flow field images corresponding to the plane according to all the best matching lines corresponding to the plane to obtain a spliced ​​flow field image of the plane includes: According to each of the best matching lines, the first flow field image and the second flow field image corresponding to each of the best matching lines are spliced ​​at the best matching line to obtain an initial spliced ​​flow field image of the plane; For each of the best matching lines, respectively, according to the wind speed information of the first flow field image and the wind speed information of the second flow field image corresponding to the best matching line, calculate the weighted wind speed information of multiple columns of pixels in the overlapping part between the first flow field image and the second flow field image corresponding to the best matching line; The initial spliced ​​flow field image is smoothed according to all weighted wind speed information to obtain the spliced ​​flow field image of the plane.

7. The condensation air volume measurement method according to claim 6, characterized in that: The step of calculating the weighted wind speed information of multiple columns of pixels in the overlapping portion between the first flow field image and the second flow field image corresponding to the best matching line according to the wind speed information of the first flow field image and the wind speed information of the second flow field image corresponding to the best matching line comprises: By formula: Calculate the weighted wind speed information u of the lth column of pixels in the overlapping part l and v l ; Among them, u l represents the two-dimensional stream velocity array of the l-th column of pixels, v l represents the two-dimensional spanwise velocity array of the lth column of pixels, b represents the serial number of the pixel column corresponding to the best matching line in the overlapping part, u LA represents the two-dimensional streamwise velocity array of a column of pixels corresponding to the best matching line in the first flow field image, u LB represents a two-dimensional streamwise velocity array of a column of pixels corresponding to the best matching line in the second flow field image, v LA represents the two-dimensional spanwise velocity array of a column of pixels corresponding to the best matching line in the first flow field image, v LB A two-dimensional spanwise velocity array representing a column of pixels corresponding to the best matching line in the second flow field image.

8. The condensing air volume measurement method according to claim 1, characterized in that: The determining of the effective flow field image area in the spliced ​​flow field image based on the wind speed information in the spliced ​​flow field image includes: By formula: Calculate the velocity gradient G of each pixel of the spliced ​​flow field image; Wherein, U represents the sum of the two-dimensional flow velocity and the two-dimensional span velocity in the spliced ​​flow field image, and y represents the vertical direction to the air inlet of the target high-speed train air conditioner; A line composed of all pixels with a velocity gradient as a preset value is used as an isoline, the spliced ​​flow field image is segmented using the isoline as a segmentation line, and the portion of the segmentation result close to the plane where the air inlet of the target high-speed train air conditioner is located is used as the effective flow field image area.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for measuring the condensing air volume of the high-speed train air conditioner as described in any one of claims 1 to 8 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for measuring the condensing air volume of a high-speed train air conditioner as described in any one of claims 1 to 8 is implemented.

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