CN110702724B - Imaging method of high-temperature wind tunnel - Google Patents
Imaging method of high-temperature wind tunnel Download PDFInfo
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- CN110702724B CN110702724B CN201811243870.6A CN201811243870A CN110702724B CN 110702724 B CN110702724 B CN 110702724B CN 201811243870 A CN201811243870 A CN 201811243870A CN 110702724 B CN110702724 B CN 110702724B
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- 238000003384 imaging method Methods 0.000 title claims abstract description 41
- 239000000463 material Substances 0.000 claims abstract description 116
- 230000001502 supplementing effect Effects 0.000 claims abstract description 114
- 238000012545 processing Methods 0.000 claims abstract description 31
- 238000010438 heat treatment Methods 0.000 claims abstract description 14
- 239000013589 supplement Substances 0.000 claims abstract description 5
- 230000007246 mechanism Effects 0.000 claims description 63
- 238000000034 method Methods 0.000 claims description 23
- 238000012360 testing method Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 6
- 238000002679 ablation Methods 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 238000001514 detection method Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000011326 mechanical measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- 230000005855 radiation Effects 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
- G01M9/06—Measuring arrangements specially adapted for aerodynamic testing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/56—Cameras or camera modules comprising electronic image sensors; Control thereof provided with illuminating means
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/70—Circuitry for compensating brightness variation in the scene
- H04N23/71—Circuitry for evaluating the brightness variation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/70—Circuitry for compensating brightness variation in the scene
- H04N23/73—Circuitry for compensating brightness variation in the scene by influencing the exposure time
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/70—Circuitry for compensating brightness variation in the scene
- H04N23/74—Circuitry for compensating brightness variation in the scene by influencing the scene brightness using illuminating means
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Abstract
The invention relates to an imaging method of a high-temperature wind tunnel. Comprising the following steps: judging whether the high-temperature wind tunnel is in a heating state or not; when the material to be detected is in a heating state, an image of the material to be detected is acquired through an image acquisition device, and the image of the material to be detected is transmitted to a processing device; collecting the surface temperature of the material to be detected through a temperature collecting device, and transmitting the surface temperature of the material to be detected to a processing device; the processing device acquires an image of the region of interest according to the image of the material to be detected, calculates the gray value of the image of the region of interest, and transmits the gray value to the light supplementing control device; the light supplementing control device generates a light supplementing control signal according to the surface temperature of the material to be detected and the gray value of the image of the region of interest, and transmits the light supplementing control signal to the light supplementing device; and the light supplementing device supplements light to the material to be detected according to the light supplementing control signal. The light supplementing device is arranged to compensate the image of the material to be detected, so that the device can further adapt to large-amplitude temperature change and improve the quality of the image of the material to be detected.
Description
The application is "the application number is: 2018107448905, the application date is 2018, 07 and 10, and the invention name is: imaging systems and methods for high temperature wind tunnels.
Technical Field
The invention relates to the technical field of engineering materials, in particular to an imaging method of a high-temperature wind tunnel.
Background
The high-temperature wind tunnel can carry out high-temperature ablation and oxidation on the detected material, so that the purpose of detecting the performance of the detected material is achieved. Most high-temperature test pieces need to be subjected to high-temperature loading test in a high-temperature wind tunnel. The non-contact high-temperature three-dimensional digital image correlation method (3D-DIC) is a method for mechanically measuring a detected material in a high-temperature wind tunnel. The non-contact high-temperature three-dimensional digital image correlation method (3D-DIC) has the advantages of high precision, no damage, non-contact, large visual field and the like. However, the above method needs to rely on high quality images, so obtaining high quality images becomes a key for non-contact mechanical measurements.
When imaging the detected material in the high-temperature wind tunnel, the imaging device is firstly required to be placed on the tripod, then the tripod is placed in front of the observation window of the high-temperature wind tunnel to build the image acquisition platform, and the imaging device acquires the image of the detected material in the high-temperature wind tunnel through the observation window. As the temperature in the high-temperature wind tunnel is changed severely, the gradient of the brightness change of the image of the material to be detected is large, and the quality of the image of the material to be detected is seriously affected.
Disclosure of Invention
Based on the above, it is necessary to provide an imaging system and method of a high-temperature wind tunnel, aiming at the problem that the gradient of the brightness change of the image is large and the quality of the image of the material to be detected is further seriously affected.
The imaging method of the high-temperature wind tunnel comprises the following steps of: the method comprises the steps of (1) obtaining state information of a high-temperature wind tunnel; the state information of the high-temperature wind tunnel comprises: the high-temperature wind tunnel is in a heating state and the high-temperature wind tunnel is not in a heating state; (2) When the high-temperature wind tunnel is in a heating state, acquiring an image of a material to be detected in real time through an image acquisition device, and transmitting the acquired image of the material to be detected to the processing device; collecting the surface temperature of the material to be detected in real time through a temperature collecting device, and transmitting the collected surface temperature of the material to be detected to the processing device; (3) The processing device acquires an image of the region of interest according to the image of the material to be detected, and calculates the gray value of the image of the region of interest; (4) The light supplementing control device generates a light supplementing control signal according to the surface temperature of the material to be detected and the gray value of the region-of-interest image, and transmits the light supplementing control signal to the light supplementing device; (5) And the light supplementing device supplements light to the material to be detected according to the light supplementing control signal.
In one embodiment, the method further comprises the following steps after the step (1): when the high-temperature wind tunnel is in an unheated state, acquiring an image of the material to be detected in real time through an image acquisition device, and transmitting the acquired image of the material to be detected to the processing device; the processing device acquires an image of the region of interest according to the image of the material to be detected, and calculates an average gray value of the image of the region of interest; the light supplementing control device compares the average gray value of the region-of-interest image with a preset threshold value; when the average gray value of the region of interest image is larger than the preset threshold value, the light supplementing control device generates a light supplementing control signal; the light supplementing device reduces the light supplementing power according to the light supplementing control signal.
In one embodiment, the comparing the average gray value of the region of interest image with a preset threshold value further includes: when the average gray value of the region of interest image is smaller than the preset threshold value, the light supplementing control device generates a light supplementing control signal; the light supplementing device increases the light supplementing power according to the light supplementing control signal.
In one embodiment, the method further comprises: the processing device generates an exposure control signal according to the surface temperature of the material to be detected and the gray value of the region-of-interest image; the image acquisition device controls exposure time according to the exposure control signal.
In one embodiment, the imaging system further comprises a fixture; the method further comprises the steps of: and fixing the image acquisition device, the temperature acquisition device and the light supplementing device on the outer wall of the high-temperature wind tunnel by using a fixing device.
In one embodiment, the securing means comprises: the device comprises a fixed bracket, a first fixed mechanism, a second fixed mechanism and a third fixed mechanism; the fixed bracket is fixedly connected with the outer wall of the high-temperature wind tunnel; the first fixing mechanism is movably connected with the fixing bracket, and the image acquisition device is connected with the first fixing mechanism; the second fixing mechanism is movably connected with the fixing bracket, and the temperature acquisition device is connected with the second fixing mechanism; the third fixing mechanism is movably connected with the fixing support, and the light supplementing device is connected with the third fixing mechanism.
In one embodiment, the fixing bracket includes: the wind tunnel fixing rod comprises at least one wind tunnel fixing rod, a plurality of fixing blocks and cross bars and/or vertical bars; the wind tunnel fixing rod is perpendicular to the high-temperature wind tunnel outer wall and is connected with the high-temperature wind tunnel outer wall through a fixing block; the cross rod and the vertical rod are mutually perpendicular and are connected with the wind tunnel fixing rod through the fixing block.
In one embodiment, the first securing mechanism includes: at least one first fixed rod, at least one camera cradle head and at least one fixed block; the image acquisition device comprises at least one image acquisition mechanism; one end of the first fixed rod is movably connected with the cross rod or the vertical rod through a fixed block, and the camera cradle head is fixedly arranged at the other end of the first fixed rod; the camera cradle head is fixedly connected with the image acquisition mechanism and used for adjusting the image acquisition angle of the image acquisition mechanism.
In one embodiment, the second securing mechanism includes: the second fixing rod, the first clamp and the fixing block; one end of the second fixing rod is movably connected with the cross rod or the vertical rod through a fixing block, and the first clamp is fixedly arranged at the other end of the second fixing rod; the first clamp is fixedly connected with the temperature acquisition device and used for fixedly arranging the temperature acquisition device at a preset position.
In one embodiment, the third fixing mechanism includes: a third fixing rod, a second clamp and a fixing block; one end of the third fixing rod is movably connected with the cross rod or the vertical rod through a fixing block, and the second clamp is fixedly arranged at the other end of the third fixing rod; the second clamp is fixedly connected with the light supplementing device and used for fixedly arranging the light supplementing device at a preset position.
According to the imaging method of the high-temperature wind tunnel, the image acquisition device and the temperature acquisition device are fixedly arranged on the observation window through the fixing device on the outer wall of the high-temperature wind tunnel, so that the image acquisition device and the temperature acquisition device can accurately acquire the image of the material to be detected and the surface temperature of the material to be detected. And acquiring an image of the region of interest according to the image of the material to be detected, calculating the gray value of the image of the region of interest, and further obtaining the image of the material to be detected. The light supplementing control device receives the surface temperature of the material to be detected and the gray value of the image of the region of interest to generate a light supplementing control signal, and the light supplementing control device is controlled by the light supplementing control signal. The light supplementing device is arranged to compensate the image of the material to be detected, so that the device can further adapt to large-amplitude temperature change and improve the quality of the image of the material to be detected.
The imaging system of the high-temperature wind tunnel is integrally fixed on the outer wall of the wind tunnel, and can effectively weaken the influence of ground vibration generated by air pressure on an imaging device.
Drawings
FIG. 1 is a schematic diagram of an imaging system of a high temperature wind tunnel in one embodiment;
FIG. 2 is a schematic diagram of an imaging system of a high temperature wind tunnel in another embodiment;
FIG. 3 is a block diagram of an imaging system of a high temperature wind tunnel in one embodiment;
FIG. 4 is a flow chart of a method of imaging a high temperature wind tunnel in one embodiment.
Description of the drawings: 100 is an image acquisition device, 200 is a temperature acquisition device, 300 is a processing device, 400 is a fixing device, 410 is a fixing bracket, 411 is a wind tunnel fixing rod, 412 is a cross rod, 413 is a vertical rod, 420 is a first fixing mechanism, 421 is a first fixing rod, 422 is a camera cradle head, 430 is a second fixing mechanism, 431 is a second fixing rod, 432 is a first clamp, 440 is a third fixing mechanism, 441 is a third fixing rod, 442 is a second clamp, 450 is a fixing block, 500 is a light supplementing control device, and 600 is a light supplementing device.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
The high-temperature alloy and the composite material are widely applied to the fields of aerospace and the like due to the good mechanical property and high-temperature resistance. In particular in the case of aerosupersonic flight, the aerodynamic heat borne by the aircraft profile increases with the increase of the aircraft speed, and in the case of ultra-high sound speed flight, the structural material of the aircraft surface oxidizes due to the aerodynamic ablation. In order to simulate hypersonic flight environment of an aircraft, a high-temperature simulation experiment is adopted to test high-temperature resistance of structural materials of the aircraft, wherein the most important simulation mode is to detect the structure of the materials through a high-temperature wind tunnel. Existing high-temperature wind tunnel is usually a gas pneumatic and electric arc wind tunnel
Referring to fig. 1-3, fig. 1 is a schematic structural diagram of an imaging system of a high-temperature wind tunnel in an embodiment; FIG. 2 is a schematic diagram of an imaging system of a high temperature wind tunnel in another embodiment; FIG. 3 is a block diagram of an imaging system of a high temperature wind tunnel in one embodiment.
1-3, an imaging system of a high temperature wind tunnel, the high temperature wind tunnel is used for performing high temperature oxidation ablation test on a material to be detected, the high temperature wind tunnel is provided with an observation window, the system comprises: an image pickup device 100, a temperature pickup device 200, a processing device 300, a light supplementing control device 500, and a light supplementing device 600; the image acquisition device 100 is arranged at the observation window and is used for acquiring an image of a material to be detected in real time; the temperature acquisition device 200 is disposed in the observation window, and is configured to acquire a surface temperature of a material to be detected in synchronization with the image acquisition device 100; the processing device 300 is connected to the image acquisition device 100 and the temperature acquisition device 200, and is configured to receive an image of a material to be detected and a surface temperature of the material to be detected, acquire an image of a region of interest according to the image of the material to be detected, and calculate a gray value of the image of the region of interest; the light supplementing control device 500 is connected to the processing device 300, and is configured to obtain a surface temperature of the material to be detected and a gray value of the region of interest image, and generate a light supplementing control signal according to the surface temperature of the material to be detected and the gray value of the region of interest image; the light supplementing device 600 is disposed at the observation window and electrically connected to the light supplementing device 500, and is configured to receive a light supplementing control signal, and supplement light to the material to be detected according to the light supplementing control signal.
Specifically, the image capturing device 100 and the temperature capturing device 200 are disposed at the observation window of the outer wall of the high temperature wind tunnel, and are stably fixed to the outer wall of the high temperature wind tunnel by the fixing device 400. And placing the material to be detected in a high-temperature wind tunnel to carry out high-temperature ablation oxidation. The image of the material to be detected and the surface temperature of the material to be detected are acquired through the image acquisition device 100 and the temperature acquisition device 200 which are arranged at the high-temperature wind tunnel observation window. The image capturing device 100 captures a surface of the material to be detected through the observation window, obtains an image of the material to be detected, and transmits the image of the material to be detected to the processing device 300. The temperature acquisition device 200 is aligned to the surface of the material to be detected through the observation window, the temperature acquisition device 200 acquires the surface temperature of the material to be detected in synchronization with the image acquisition device 100, and transmits the surface temperature of the material to be detected to the processing device 300. The image capturing device 100 includes at least one image capturing mechanism, which may be a video camera, preferably a photo-coupled device camera (CCD camera), or the like. The temperature acquisition device 200 may be a non-contact temperature sensor, preferably an infrared thermometer or a pyrometer. The processing device 300 receives the image of the material to be detected and the surface temperature of the material to be detected, selects an image in a preset range as an image of the region of interest from the image of the material to be detected by taking the material to be detected as a center, and calculates the gray value of each pixel point of the image of the region of interest. The processing device 300 is connected to the image capturing device 100 and the temperature capturing device 200, and may be electrically connected or wirelessly connected, preferably electrically connected. The processing device 300 is further configured to generate an exposure control signal according to the surface temperature of the material to be detected and the gray value of the region of interest image, and the image acquisition device 100 controls the exposure time according to the exposure control signal. When a material to be detected is placed in a high-temperature wind tunnel to perform high-temperature ablation oxidation, as the temperature change in the high-temperature wind tunnel is severe, the gradient of the brightness change of the image of the material to be detected is large, the quality of the image of the material to be detected is seriously affected, and then the light supplementing control device 500 and the light supplementing device 600 are required to be arranged, the light supplementing control device 500 obtains the gray value of the image of the region of interest and the surface temperature of the material to be detected through calculation by the processing device 300, and generates a light supplementing control signal according to the surface temperature of the material to be detected and the gray value of the image of the region of interest, and the light supplementing control signal is transmitted to the light supplementing device 600 to control the light supplementing device 600 to supplement light to the material to be detected. The light supplementing control device 500 is connected to the processing device 300 in an electrical connection or a wireless connection, preferably in an electrical connection, and the light supplementing control device 500 and the processing device 300 communicate with each other through an RS485 serial interface. The light emitted from the light supplementing device 600 passes through the observation window and irradiates the surface of the material to be detected for supplementing light. Therefore, the light supplementing device 600 needs to be disposed at the observation window, so that light can be irradiated on the surface of the material to be detected through the observation window. The light supplementing device 600 may be a light source with any color, preferably a blue light source. When the high-temperature wind tunnel is in a heating state, the light supplementing control device 500 generates a light supplementing control signal according to the surface temperature of the material to be detected and the gray value of the region of interest, and transmits the light supplementing control signal to the light supplementing device 600, and the light supplementing device 600 adjusts the light supplementing power according to the light supplementing control signal. When the high-temperature wind tunnel is not in a heating state, the light supplementing control device 500 compares the average gray value of the region-of-interest image with a preset threshold value; when the average gray value is greater than the preset threshold, a light supplementing control signal is sent to the light supplementing device 600, and the light supplementing device 600 reduces the light supplementing power according to the light supplementing control signal; when the average gray value is smaller than the preset threshold, a light-compensating control signal is transmitted to the light-compensating device 600, and the light-compensating device 600 increases the light-compensating power according to the light-compensating control signal. The acquisition of the image of the material to be detected under the high-temperature environment generally requires light supplementing of the material to be detected, and a filter is arranged between the lens and the camera, so that the interference of the radiation light on the acquired image is reduced. However, the fixed-power light compensating device 600 cannot be adapted to the test with large brightness variation, so the light compensating device 600 in this embodiment is a power-adjustable light compensating device 600 and can be adapted to the test with large brightness variation.
Preferably, the system further comprises a fixing device fixedly connected with the outer wall of the high-temperature wind tunnel, and the image acquisition device, the temperature acquisition device and the light supplementing device are connected with the fixing device.
Specifically, the image capturing device 100 and the temperature capturing device 200 are fixed at the observation window of the outer wall of the high temperature wind tunnel by the fixing device 400. The lens of the image acquisition device 100 is prevented from deviating due to vibration generated on the ground when the high-temperature wind tunnel heats the detected material, and the acquired image quality is prevented from being influenced. And when the high-temperature wind tunnel tests the material to be detected, the time for installing and debugging the image acquisition device 100 and the temperature acquisition device 200 is limited, the image acquisition device 100 and the temperature acquisition device 200 are fixed on the outer wall of the high-temperature wind tunnel through the fixing device 400, so that equipment can be conveniently and rapidly installed, the debugging time can be saved, and the high-temperature wind tunnel detection efficiency is improved. The fixing device 400 is further used for fixing the light supplementing device 600 at the outer wall observation window of the high-temperature wind tunnel. Because the observation window of the high-temperature wind tunnel is limited in size, the fixing device 400 is used for arranging the image acquisition device 100, the temperature acquisition device 200 and the light supplementing device 600 in the observation window, so that the installation difficulty can be reduced.
Preferably, the fixing device 400 includes: a fixed bracket 410, a first fixing mechanism 420, a second fixing mechanism 430, and a third fixing mechanism 440; the fixed bracket 410 is fixedly connected with the outer wall of the high-temperature wind tunnel; the first fixing mechanism 420 is movably connected with the fixing bracket 410, and is configured to movably set the image capturing device 100 at the preset position of the observation window; the second fixing mechanism 430 is movably connected to the fixing bracket 410, and is configured to movably set the temperature collecting device 200 at a preset position of the observation window; the third fixing mechanism 440 is movably connected to the fixing bracket 410, and is configured to movably set the light compensating device 600 at the preset position of the observation window.
Specifically, the fixing bracket 410 includes: at least one wind tunnel fixing bar 411 and a plurality of fixing blocks 450, and further comprises a cross bar 412 and/or a vertical bar 413; the wind tunnel fixing rod 411 is perpendicular to the high-temperature wind tunnel outer wall and is connected with the high-temperature wind tunnel outer wall through a fixing block 450; the cross bar 412 and the vertical bar 413 are perpendicular to each other and are connected to the wind tunnel fixing bar 411 through a fixing block 450. Wherein, the fixed block 450 for fixing the wind tunnel fixed rod 411 is a high temperature resistant fixed block 450, the vertical rod 413 is fixedly arranged on two wind tunnel fixed rods 411 arranged in the vertical direction, one end of the cross rod 412 is connected with the other wind tunnel fixed rod 411, the other end of the cross rod 412 can be connected with the wind tunnel fixed rod 411 in the vertical screen direction, and the cross rod 412 and the vertical rod 413 can also be fixedly connected through the fixed block 450. The cross bar 412 and the vertical bar 413 are marked with scales, and the first fixing mechanism 420, the second fixing mechanism 430 and the third fixing mechanism 440 can move on the cross bar 412 or the vertical bar 413, so that the positions of the first fixing mechanism 420, the second fixing mechanism 430 and the third fixing mechanism 440 can be further accurately adjusted according to the scales. If the observation window of the high temperature wind tunnel is large enough, a fixing rod can be used to fix a cross rod 412 through the fixing rod, the first fixing mechanism 420, the second fixing mechanism 430 and the third fixing mechanism 440 are all fixed on the cross rod 412, and scales are marked on the cross rod 412 for accurately adjusting the positions; it is also possible to fix a vertical rod 413 by a fixing rod, and fix the first fixing mechanism 420, the second fixing mechanism 430 and the third fixing mechanism 440 on the vertical rod 413, where the vertical rod 413 is marked with scales for precisely adjusting the position.
Specifically, the first fixing mechanism 420 includes: at least one first fixing bar 421, at least one camera head 422, and at least one fixing block 450; one end of the first fixing rod 421 is movably connected with the cross rod 412 or the vertical rod 413 through a fixing block 450, and the camera pan-tilt 422 is fixedly arranged at the other end; the camera cradle head 422 is fixedly connected with the image acquisition mechanism, and is used for fixedly arranging the first image acquisition mechanism at the preset position of the observation window and adjusting the image acquisition angle of the image acquisition mechanism. The number of the first fixing rods 421 and the camera holders 422 is the same as the number of the image capturing mechanisms of the image capturing apparatus 100. The first fixing rod 421 can be connected with the cross rod 412 or the vertical rod 413, and only the image acquisition mechanism needs to be ensured to be arranged at the observation window. The camera cradle head 422 is a supporting device for installing and fixing a camera, and the image acquisition mechanism is installed on the camera cradle head 422, so that the angle of the image acquisition mechanism can be adjusted, and the acquisition view field can be further adjusted. The first fixing rod 421 is marked with a scale, and the camera cradle head 422 can move on the first fixing rod 421 and further can adjust the position of the image acquisition mechanism according to the scale.
Specifically, the second fixing mechanism 430 includes: a second fixing lever 431, a first clamp 432, and a fixing block 450; one end of the second fixing rod 431 is movably connected with the cross rod 412 or the vertical rod 413 through a fixing block 450, and the other end is fixedly provided with the first clamp 432; the first clamp 432 is fixedly connected to the temperature acquisition device 200, and is configured to fixedly set the temperature acquisition device 200 at the preset position of the observation window. The second fixing rod 431 may be connected to the cross rod 412 or the vertical rod 413, and only needs to ensure that the temperature collecting device 200 can be disposed in the observation window. The first clamp 432 is used for fixing the temperature acquisition device 200, so that the temperature acquisition device 200 is fixedly arranged at a corresponding position so as to acquire the surface temperature of the material to be detected. The second fixed rod 431 is marked with a scale, and the first clamp 432 can move on the second fixed rod 431, and further, the position of the temperature acquisition device 200 can be adjusted according to the scale.
Specifically, the third fixing mechanism 440 includes: a third fixing rod 441, a second clamp 442, and a fixing block 450; one end of the third fixing rod 441 is movably connected with the cross rod 412 or the vertical rod 413 through a fixing block 450, and the other end is fixedly provided with the second clamp 442; the second clamp 442 is fixedly connected to the light compensating device 600, and is configured to fixedly position the light compensating device 600 at the preset position of the observation window. The third fixing rod 441 may be connected to the cross rod 412 or the vertical rod 413, which only needs to ensure that the light compensating device 600 can be disposed in the observation window. The second fixture 442 is used for fixing the light compensating device 600, so that the light compensating device 600 is fixedly disposed at a corresponding position for compensating light of the material to be detected. The third fixing rod 441 is marked with a scale, and the second clamp 442 can move on the third fixing rod 441, and further can adjust the position of the light compensating device 600 according to the scale.
Referring to fig. 4, fig. 4 is a flowchart of a method for imaging a high-temperature wind tunnel according to an embodiment.
As shown in fig. 4, an imaging method of a high-temperature wind tunnel is provided, which may include the following steps:
step S102: and acquiring state information of the high-temperature wind tunnel.
Specifically, the state information of the high-temperature wind tunnel includes: the high temperature wind tunnel is in a heating state and the high temperature wind tunnel is not in a heating state.
Step S104: when the high-temperature wind tunnel is in a heating state, images of the material to be detected and the surface temperature are acquired in real time.
Specifically, the image acquisition device shoots the surface of the material to be detected through the observation window to obtain an image of the material to be detected. The temperature acquisition device is aligned to the surface of the material to be detected through the observation window, synchronously acquires the surface temperature of the material to be detected with the image acquisition device, and transmits the surface temperature of the material to be detected to the processing device.
Step S106: and acquiring an image of the region of interest according to the image of the material to be detected, and calculating the gray value of the image of the region of interest.
Specifically, the processing device receives an image of a material to be detected and the surface temperature of the material to be detected, takes the material to be detected as a center in the image of the material to be detected, selects an image in a preset range as an image of a region of interest, and calculates the gray value of each pixel point of the image of the region of interest.
Step S108: and generating a light supplementing control signal according to the surface temperature of the material to be detected and the gray value of the region of interest.
Specifically, the light supplementing control device generates a light supplementing control signal according to the relation between the surface temperature of the detection material and the gray value of the region of interest, and transmits the light supplementing control signal to the light supplementing module.
Step S110: and adjusting the light supplementing power according to the light supplementing control signal.
Specifically, the light supplementing module adjusts the light supplementing power according to the received light supplementing control signal.
In one embodiment, a method for imaging a high temperature wind tunnel may further include the steps of:
step S202: and when the high-temperature wind tunnel is not in a heating state, acquiring an image of the material to be detected in real time.
Specifically, the image acquisition device shoots the surface of the material to be detected through the observation window to obtain an image of the material to be detected.
Step S204: and acquiring an image of the region of interest according to the image of the material to be detected, and calculating the average gray value of the image of the region of interest.
Specifically, the processing device receives an image of a material to be detected, takes the material to be detected as a center in the image of the material to be detected, selects an image in a preset range as an image of a region of interest, calculates gray values of all pixel points of the image of the region of interest, and calculates an average gray value of the image of the region of interest according to the gray values of all pixel points of the image of the region of interest.
Step S206: comparing the average gray value with a preset threshold value; when the average gray value is larger than a preset threshold value, reducing the light supplementing power; and when the average gray value is smaller than the preset threshold value, increasing the light supplementing power.
Specifically, if the region of interest image is an 8-bit image, the preset threshold may be set to 125. That is, when the average gray value is greater than 125, the light-supplementing power is reduced; when the average gray value is less than 125, the light filling power is increased.
According to the imaging system of the high-temperature wind tunnel, the image acquisition device and the temperature acquisition device are fixedly arranged on the observation window through the fixing device on the outer wall of the high-temperature wind tunnel, so that the image acquisition device and the temperature acquisition device can accurately acquire the image of the material to be detected and the surface temperature of the material to be detected. And acquiring an image of the region of interest according to the image of the material to be detected, calculating the gray value of the image of the region of interest, and further obtaining the image of the material to be detected. The light supplementing control device receives the surface temperature of the material to be detected and the gray value of the image of the region of interest to generate a light supplementing control signal, and the light supplementing control device is controlled by the light supplementing control signal. The light supplementing device is arranged to compensate the image of the material to be detected, so that the device can further adapt to large-amplitude temperature change and improve the quality of the image of the material to be detected.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (10)
1. The imaging method of the high-temperature wind tunnel is characterized in that the imaging is realized through an imaging system, the imaging system comprises an image acquisition device, a temperature acquisition device, a processing device, a light supplementing control device and a light supplementing device, and the temperature acquisition device comprises: a non-contact temperature sensor; the imaging method of the high-temperature wind tunnel comprises the following steps:
(1) Acquiring state information of a high-temperature wind tunnel; the state information of the high-temperature wind tunnel comprises: the high-temperature wind tunnel is in a heating state and the high-temperature wind tunnel is not in a heating state;
(2) When the high-temperature wind tunnel is in a heating state, acquiring an image of a material to be detected in real time through an image acquisition device, and transmitting the acquired image of the material to be detected to the processing device; collecting the surface temperature of the material to be detected in real time through a temperature collecting device, and transmitting the collected surface temperature of the material to be detected to the processing device;
(3) The processing device acquires an image of the region of interest according to the image of the material to be detected, and calculates the gray value of the image of the region of interest;
(4) The light supplementing control device generates a light supplementing control signal according to the surface temperature of the material to be detected and the gray value of the region-of-interest image, and transmits the light supplementing control signal to the light supplementing device;
(5) And the light supplementing device supplements light to the material to be detected according to the light supplementing control signal.
2. The method of imaging a high temperature wind tunnel of claim 1, further comprising the step, after step (1), of:
when the high-temperature wind tunnel is in an unheated state, acquiring an image of the material to be detected in real time through an image acquisition device, and transmitting the acquired image of the material to be detected to the processing device;
the processing device acquires an image of the region of interest according to the image of the material to be detected, and calculates an average gray value of the image of the region of interest;
the light supplementing control device compares the average gray value of the region-of-interest image with a preset threshold value;
when the average gray value of the region of interest image is larger than the preset threshold value, the light supplementing control device generates a light supplementing control signal;
the light supplementing device reduces the light supplementing power according to the light supplementing control signal.
3. The method for imaging a high-temperature wind tunnel according to claim 2, wherein comparing the average gray value of the region of interest image with a preset threshold value further comprises:
when the average gray value of the region of interest image is smaller than the preset threshold value, the light supplementing control device generates a light supplementing control signal;
the light supplementing device increases the light supplementing power according to the light supplementing control signal.
4. The method of imaging a high temperature wind tunnel of claim 1, further comprising:
the processing device generates an exposure control signal according to the surface temperature of the material to be detected and the gray value of the region-of-interest image;
the image acquisition device controls exposure time according to the exposure control signal.
5. The method of imaging a high temperature wind tunnel of claim 1, wherein the imaging system further comprises a fixture; the method further comprises the steps of:
and fixing the image acquisition device, the temperature acquisition device and the light supplementing device on the outer wall of the high-temperature wind tunnel by using the fixing device.
6. The method of imaging a high temperature wind tunnel of claim 5, wherein the fixture comprises: the device comprises a fixed bracket, a first fixed mechanism, a second fixed mechanism and a third fixed mechanism;
the fixed bracket is fixedly connected with the outer wall of the high-temperature wind tunnel;
the first fixing mechanism is movably connected with the fixing bracket, and the image acquisition device is connected with the first fixing mechanism;
the second fixing mechanism is movably connected with the fixing bracket, and the temperature acquisition device is connected with the second fixing mechanism;
the third fixing mechanism is movably connected with the fixing support, and the light supplementing device is connected with the third fixing mechanism.
7. The method of imaging a high temperature wind tunnel of claim 6, wherein the stationary support comprises: the wind tunnel fixing rod comprises at least one wind tunnel fixing rod, a plurality of fixing blocks and cross bars and/or vertical bars;
the wind tunnel fixing rod is perpendicular to the high-temperature wind tunnel outer wall and is connected with the high-temperature wind tunnel outer wall through a fixing block; the cross rod and the vertical rod are mutually perpendicular and are connected with the wind tunnel fixing rod through the fixing block.
8. The method of imaging a high temperature wind tunnel of claim 7, wherein the first securing mechanism comprises: at least one first fixed rod, at least one camera cradle head and at least one fixed block;
the image acquisition device comprises at least one image acquisition mechanism;
one end of the first fixed rod is movably connected with the cross rod or the vertical rod through a fixed block, and the camera cradle head is fixedly arranged at the other end of the first fixed rod;
the camera cradle head is fixedly connected with the image acquisition mechanism and used for adjusting the image acquisition angle of the image acquisition mechanism.
9. The method of imaging a high temperature wind tunnel of claim 7, wherein the second securing mechanism comprises: the second fixing rod, the first clamp and the fixing block;
one end of the second fixing rod is movably connected with the cross rod or the vertical rod through a fixing block, and the first clamp is fixedly arranged at the other end of the second fixing rod;
the first clamp is fixedly connected with the temperature acquisition device and used for fixedly arranging the temperature acquisition device at a preset position.
10. The method of imaging a high temperature wind tunnel of claim 7, wherein the third securing mechanism comprises: a third fixing rod, a second clamp and a fixing block;
one end of the third fixing rod is movably connected with the cross rod or the vertical rod through a fixing block, and the second clamp is fixedly arranged at the other end of the third fixing rod;
the second clamp is fixedly connected with the light supplementing device and used for fixedly arranging the light supplementing device at a preset position.
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| CN114697537B (en) * | 2020-12-31 | 2024-05-10 | 浙江清华柔性电子技术研究院 | Image acquisition method, image sensor, and computer-readable storage medium |
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| CN110702725B (en) | 2024-02-20 |
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