Vibration displacement measurement method and related device
By using optical measurement methods, combined with camera-acquired reflective stripe images and multi-parameter calculations, the problem of low accuracy in measuring vibration displacement of thin-walled skin of underwater vehicles was solved, achieving high-precision non-contact measurement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHWESTERN POLYTECHNICAL UNIV
- Filing Date
- 2026-02-10
- Publication Date
- 2026-05-12
AI Technical Summary
Existing methods for measuring the vibration displacement of thin-walled skin of underwater vehicles suffer from low accuracy and susceptibility to high-pressure and corrosive underwater environments. Furthermore, sensor installation can damage the integrity of the skin structure.
A non-contact optical measurement method is adopted, which acquires reflected stripe images by a camera inside the underwater vehicle. The vibration displacement is calculated by combining the light intensity distribution of the stripe image of each pixel, the background light intensity, the stripe contrast, the initial carrier phase, and the system displacement sensitivity coefficient with the cosine function formula.
It improves the accuracy and effectiveness of vibration displacement measurement, avoids damage to the skin during sensor installation, and adapts to complex underwater environments.
Smart Images
Figure CN122015657A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of underwater vehicle testing technology, and in particular to a vibration displacement measurement method and related apparatus. Background Technology
[0002] As a critical external structure, the thin-walled skin of an underwater vehicle directly affects its hydrodynamic performance, structural stability, and stealth capabilities due to its vibration characteristics (especially vertical vibration displacement). Because underwater vehicles operate in complex environments with high pressure, low light levels, and water scattering, and because the thin-walled skin is thin and has low stiffness, it is susceptible to minute vibrations caused by water flow disturbances and the vehicle's own vibrations. This places stringent requirements on the high-precision measurement of its vibration displacement.
[0003] Currently, common methods for measuring the vibration of underwater thin-walled structures mainly include contact measurement (such as strain gauge and accelerometer bonding measurement). Among them, the contact measurement method requires the sensor to be directly bonded to the surface of the skin to be measured, which not only damages the mirror properties and structural integrity of the skin and affects the vibration state of the skin, but also makes the underwater sealing and pressure resistance design of the sensor difficult, and it is susceptible to the effects of high pressure and corrosive environment underwater, resulting in a decrease in the accuracy of vibration displacement measurement.
[0004] Therefore, the effectiveness of vibration displacement obtained by using common methods for vibration measurement of underwater thin-walled structures is relatively low. Summary of the Invention
[0005] Therefore, it is necessary to propose a vibration displacement measurement method and related device to address the above problems, aiming to solve the problem of low effectiveness of vibration displacement measurement.
[0006] In a first aspect, embodiments of this application provide a vibration displacement measurement method, the method comprising:
[0007] Acquire a reflected stripe image captured by a camera located inside the pressure hull of the underwater vehicle body; wherein, the reflected stripe image is an image captured by the camera of the stripe pattern reflected by the thin-walled skin under test when a stripe projection device located inside the pressure hull of the underwater vehicle body projects a stripe pattern onto the mirrored thin-walled skin under test outside the underwater vehicle. The intensity distribution of the stripe image, background intensity, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient of each pixel on the reflected stripe image are obtained. Substituting the light intensity distribution of the stripe image at each pixel, the background light intensity, the stripe contrast, the initial carrier phase, and the system displacement sensitivity coefficient into the cosine function formula for the light intensity distribution of the stripe image, the vibration displacement corresponding to each target point on the thin-walled skin under test is obtained; wherein, the target point is the point corresponding to the pixel on the thin-walled skin under test, and the cosine function formula is... Let (x, y) represent the camera pixel coordinates of the pixel, I(x, y) represent the stripe image light intensity distribution of the pixel, A(x, y) represent the background light intensity of the pixel, and B(x, y) represent the stripe contrast of the pixel. denoted by , where k represents the initial carrier phase corresponding to the pixel, h represents the system displacement sensitivity coefficient, and h represents the vibration displacement.
[0008] In some embodiments, obtaining the system displacement sensitivity coefficient includes: obtaining a fixed baseline distance between the optical center of the stripe projection device and the optical center of the camera, a vertical distance between the stripe projection device and the plane of the thin-walled skin under test, and the natural frequency of the stripe pattern projected by the stripe projection device onto the thin-walled skin under test; substituting the fixed baseline distance, the vertical distance, and the natural frequency into the system displacement sensitivity coefficient calculation formula to obtain the system displacement sensitivity coefficient; wherein, the system displacement sensitivity coefficient calculation formula is as follows: , Indicates the inherent frequency, L represents the fixed baseline distance, and L represents the vertical distance.
[0009] In some embodiments, the formula for calculating the initial carrier phase of the aforementioned pixel is as follows: ; Where (x, y) represents the camera pixel coordinates of the pixel. This represents the initial carrier phase of the pixel. This indicates the inherent frequency of the stripe pattern projected by the stripe projection device onto the thin-walled skin under test.
[0010] Secondly, embodiments of this application provide a vibration displacement measuring device for implementing the method described in the first aspect, the device comprising: A stripe projection device is used to project a stripe pattern onto the mirror-finished thin-walled skin of the underwater vehicle body, when the stripe projection device is embedded inside the pressure hull of the underwater vehicle body. A camera, embedded inside the pressure hull of the underwater vehicle, is used to acquire images of the reflected stripes from the thin-walled skin under test. The processor, communicatively connected to the camera, is configured to receive the reflective stripe image transmitted by the camera and execute the various steps of the method as described in the first aspect.
[0011] In some embodiments, the vibration displacement measuring device includes: a high-rigidity frame for fixing to the main load-bearing structure on the inner surface of the pressure hull of the underwater vehicle body; the stripe projection device and the camera, respectively fixed to both sides of the high-rigidity frame by adjustable lateral movement rods and vertical telescopic rods, for forming an optical measuring body with the mirror-treated thin-walled skin of the underwater vehicle exterior; the lateral movement rods and vertical telescopic rods are used to adjust the distance between the camera and the stripe projection device, the angle between the camera and the stripe projection device and the plane of the thin-walled skin to be measured, and the distance between the camera and the stripe projection device and the plane of the thin-walled skin to be measured; the optical center of the stripe projection device and the optical center of the camera form a fixed baseline.
[0012] In some embodiments, the camera in the vibration displacement measuring device is connected to the underwater vehicle via an interface on the back of the camera, and the stripe projection device in the vibration displacement measuring device is connected to the underwater vehicle via an interface on the back of the stripe projection device; the underwater vehicle is used to supply power to the camera and the stripe projection device.
[0013] In some embodiments, the high-rigidity frame includes multiple vertical support columns, multiple horizontal bars, and multiple rigid connecting chassis. The multiple vertical support columns and the multiple horizontal bars form a cuboid structure, and the multiple horizontal bars are all connected to the top of the multiple vertical support columns. The bottom of the multiple vertical support columns is connected to the multiple rigid connecting chassis. The rigid connecting chassis are used to fix the high-rigidity frame inside the pressure hull of the underwater vehicle body.
[0014] In some embodiments, the vibration displacement measuring device further includes two inclined mounting surfaces, which are respectively fixed to the top two sides of the high-rigidity frame by an adjustable lateral moving rod and a vertical telescopic rod. The two inclined mounting surfaces are used to fix the camera and the stripe projection device, respectively.
[0015] Thirdly, embodiments of this application provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the following steps: Acquire a reflected stripe image captured by a camera located inside the pressure hull of the underwater vehicle body; wherein, the reflected stripe image is an image captured by the camera of the stripe pattern reflected by the thin-walled skin under test when a stripe projection device located inside the pressure hull of the underwater vehicle body projects a stripe pattern onto the mirrored thin-walled skin under test outside the underwater vehicle. The intensity distribution of the stripe image, background intensity, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient of each pixel on the reflected stripe image are obtained. Substituting the light intensity distribution of the stripe image at each pixel, the background light intensity, the stripe contrast, the initial carrier phase, and the system displacement sensitivity coefficient into the cosine function formula for the light intensity distribution of the stripe image, the vibration displacement corresponding to each target point on the thin-walled skin under test is obtained; wherein, the target point is the point corresponding to the pixel on the thin-walled skin under test, and the cosine function formula is... Let (x, y) represent the camera pixel coordinates of the pixel, I(x, y) represent the stripe image light intensity distribution of the pixel, A(x, y) represent the background light intensity of the pixel, and B(x, y) represent the stripe contrast of the pixel. denoted by , where k represents the initial carrier phase corresponding to the pixel, k represents the system displacement sensitivity coefficient, and h represents the vibration displacement.
[0016] Fourthly, embodiments of this application provide a computer device, including a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, the processor performs the following steps: Acquire a reflected stripe image captured by a camera located inside the pressure hull of the underwater vehicle body; wherein, the reflected stripe image is an image captured by the camera of the stripe pattern reflected by the thin-walled skin under test when a stripe projection device located inside the pressure hull of the underwater vehicle body projects a stripe pattern onto the mirrored thin-walled skin under test outside the underwater vehicle. The intensity distribution of the stripe image, background intensity, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient of each pixel on the reflected stripe image are obtained. Substituting the light intensity distribution of the stripe image at each pixel, the background light intensity, the stripe contrast, the initial carrier phase, and the system displacement sensitivity coefficient into the cosine function formula for the light intensity distribution of the stripe image, the vibration displacement corresponding to each target point on the thin-walled skin under test is obtained; wherein, the target point is the point corresponding to the pixel on the thin-walled skin under test, and the cosine function formula is... Let (x, y) represent the camera pixel coordinates of the pixel, I(x, y) represent the stripe image light intensity distribution of the pixel, A(x, y) represent the background light intensity of the pixel, and B(x, y) represent the stripe contrast of the pixel. denoted by , where k represents the initial carrier phase corresponding to the pixel, k represents the system displacement sensitivity coefficient, and h represents the vibration displacement.
[0017] The vibration displacement measurement method and related apparatus of this application obtain the vibration displacement corresponding to each target point on the thin-walled skin under test by substituting the light intensity distribution of each pixel in the reflected stripe image, background light intensity, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient of the reflected stripe image acquired by a camera located inside the pressure hull of the underwater vehicle into the cosine function form formula of the stripe image light intensity distribution. Thus, instead of relying on a single light intensity parameter, it integrates five key parameters—background light intensity, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient—and substitutes them into the cosine function form formula of the stripe image light intensity distribution to calculate the vibration displacement. Through the synergistic effect of these five parameters, the accuracy and effectiveness of calculating the vibration displacement of the thin-walled skin under test can be improved. Attached Figure Description
[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] in: Figure 1 A schematic flowchart illustrating the vibration displacement measurement method provided in this application embodiment; Figure 2 This is a structural block diagram of the vibration displacement measuring device provided in the embodiments of this application; Figure 3 A schematic diagram of the structure of a vibration displacement measuring device installed inside an underwater vehicle, as provided in an embodiment of this application; Figure 4 A theoretical illustration of the vibration displacement measurement method provided in the embodiments of this application; Figure 5 A structural block diagram of the processor provided in the embodiments of this application; Figure 6 This is a structural block diagram of a computer device in one embodiment. Detailed Implementation
[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0021] refer to Figure 1 , Figure 1 This is a flowchart illustrating the vibration displacement measurement method provided in the embodiments of this application. Specifically, it includes the following steps S1-S4: Step S1: Obtain the reflected stripe image captured by the camera located inside the pressure hull of the underwater vehicle.
[0022] The aforementioned reflected stripe image is an image captured by a camera of the stripe pattern reflected by the thin-walled skin under test, when a stripe projection device located inside the pressure hull of the underwater vehicle projects a stripe pattern onto the mirrored thin-walled skin outside the underwater vehicle.
[0023] The aforementioned underwater vehicle can be an unmanned underwater vehicle (UUV).
[0024] The aforementioned camera may be a high-speed camera, and the aforementioned stripe projection device may include an LED array or a light strip.
[0025] Step S2: Obtain the stripe image light intensity distribution, background light intensity, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient for each pixel in the reflective stripe image.
[0026] The intensity distribution of the striped image can characterize the intensity distribution of the structured light field on the camera imaging plane after reflection by the thin-walled skin mirror under test.
[0027] Step S3: Substitute the light intensity distribution of the stripe image, background light intensity, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient of each pixel into the cosine function form of the light intensity distribution of the stripe image to obtain the vibration displacement corresponding to each target point on the thin-walled skin to be tested.
[0028] Here, the target point is the point on the thin-walled skin under test corresponding to the pixel. Therefore, each pixel corresponds to one target point, and the vibration displacement h corresponding to multiple target points on the thin-walled skin under test can be obtained. Vibration displacement refers to the displacement component of each target point on the thin-walled skin under test along the surface normal direction, that is, the out-of-surface displacement.
[0029] The formula for the cosine function is as follows: ; Where (x, y) represents the camera pixel coordinates of a pixel, thus representing a single pixel; I(x, y) represents the fringe image intensity distribution of the pixel; A(x, y) represents the background intensity of the pixel; and B(x, y) represents the fringe contrast of the pixel. denoted by , where k represents the initial carrier phase corresponding to the pixel, k represents the system displacement sensitivity coefficient, and h represents the vibration displacement.
[0030] In this embodiment, instead of relying on a single light intensity parameter, five key parameters are integrated: background light intensity of the pixel, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient. These parameters are substituted into the cosine function form of the light intensity distribution of the stripe image to calculate the vibration displacement. Through the synergistic effect of these five parameters, the accuracy and effectiveness of the vibration displacement calculation of the thin-walled skin under test can be improved.
[0031] In some embodiments, obtaining the system displacement sensitivity coefficient described above may include the following steps: The fixed baseline distance between the optical center of the stripe projection device and the optical center of the camera, the vertical distance between the stripe projection device and the plane of the thin-walled skin under test, and the natural frequency of the stripe pattern projected by the stripe projection device onto the thin-walled skin under test are obtained.
[0032] Substituting the fixed baseline distance, vertical distance, and natural frequency into the system displacement sensitivity coefficient calculation formula yields the system displacement sensitivity coefficient.
[0033] The formula for calculating the displacement sensitivity coefficient of the above system can be as follows: ; in, Indicates the natural frequency. L represents the fixed baseline distance, and L represents the vertical distance.
[0034] In some embodiments, the formula for calculating the initial carrier phase of the aforementioned pixel is as follows: ; Where (x, y) represents the camera pixel coordinates of the pixel. This represents the initial carrier phase of the pixel. This indicates the natural frequency of the stripe pattern projected by the stripe projection device onto the thin-walled skin under test.
[0035] This application also provides a vibration displacement measuring device, which can be used to implement the above method, as shown in Figure 2. Figure 2The diagram below shows the structure of the vibration displacement measuring device provided in this application. The vibration displacement measuring device may include a stripe projection device, a camera, and a processor. The stripe projection device is used to project a stripe pattern onto the mirror-finished thin-walled skin of the underwater vehicle body, when the stripe projection device is embedded inside the pressure hull of the underwater vehicle body. The camera is embedded inside the pressure hull of the underwater vehicle body and is used to acquire the reflected stripe image of the thin-walled skin under test. The processor is communicatively connected to the camera and is used to receive the reflected stripe image transmitted by the camera and execute the various steps of the above method.
[0036] In one embodiment, the processor can also be used to send relevant control commands to the stripe projection device and the camera to control the stripe projection device to project stripe patterns onto the mirror-finished thin-walled skin to be tested on the outside of the pressure hull of the underwater vehicle body, and to control the camera to start so that the camera can acquire the reflected stripe images reflected by the thin-walled skin to be tested.
[0037] In this embodiment, non-contact vibration measurement of the thin-walled skin structure outside the underwater vehicle can be performed through a preset optical window on the underwater vehicle hull. The optical measurement components (camera and stripe projection device) can amplify and measure the minute vibrations of the thin wall through the principle of optical reflection amplification.
[0038] like Figure 3 As shown, Figure 3 This is a schematic diagram of a vibration displacement measuring device installed inside an underwater vehicle, provided in an embodiment of this application. The vibration displacement measuring device also includes a high-rigidity frame 1, which is used to fix the main load-bearing structure on the inner surface of the pressure hull of the underwater vehicle body.
[0039] The stripe projection device 3 and the camera 2 are fixed to both sides of the high-rigidity frame 1 by adjustable lateral movement rod 7 and vertical telescopic rod 6, respectively. They are used to form an optical measurement body with the mirror-finished thin-walled skin 9 of the underwater vehicle. The lateral movement rod 7 and the vertical telescopic rod 6 are used to adjust the distance between the camera 2 and the stripe projection device 3, the angle between the camera 2 and the stripe projection device 3 and the plane of the thin-walled skin 9, respectively, and the distance between the camera 2 and the stripe projection device 3 and the plane of the thin-walled skin 9, respectively. The optical center of the stripe projection device 3 and the optical center of the camera 2 form a fixed baseline.
[0040] In this embodiment, the optical measurement component utilizes the principle of geometric optical triangulation. By adjusting the distance between the camera 2 and the stripe projection device 3, the angle between the camera 2 and the stripe projection device 3 and the plane of the thin-walled skin 9 to be measured, and the distance between the camera 2 and the stripe projection device 3 and the plane of the thin-walled skin 9 to be measured, the baseline distance and relative angle between the camera 2 and the stripe projection device 3 and the plane of the thin-walled skin 9 to be measured can be optimized, thereby achieving highly sensitive non-contact measurement of the minute vibration displacement of the thin-walled structure.
[0041] The high-rigidity frame adopts an integrated frame design, combining the stripe projection device and camera into a single structure, which can isolate the influence of external shell deformation on the optical path. The stripe projection device and camera are mounted inside the underwater vehicle through the high-rigidity frame, which can avoid affecting the thin-walled vibration results and fluid shape of the underwater vehicle.
[0042] In some embodiments, the camera 2 and the stripe projection device 3 in the vibration displacement measuring device are powered and communicate with the underwater vehicle via interfaces on their backs, respectively. Specifically, the camera 2 in the vibration displacement measuring device is connected to the underwater vehicle via an interface on its back, and the stripe projection device 3 in the vibration displacement measuring device is connected to the underwater vehicle via an interface on its back. The underwater vehicle provides power to the camera and the stripe projection device.
[0043] The optical measurement components (camera and stripe projection device) can communicate with the underwater vehicle via interfaces 5 and 6 on the back. With the help of the underwater vehicle's power supply, the optical measurement components (camera and stripe projection device) can achieve long-term stable monitoring of thin walls, ensuring that the vibration displacement measurement device has the endurance required to meet long-term measurement tasks.
[0044] In some embodiments, the high-rigidity frame 1 includes multiple vertical support columns, multiple horizontal bars, and multiple rigid connecting chassis. The multiple vertical support columns and multiple horizontal bars form a cuboid structure, and each horizontal bar is connected to the top of the multiple vertical support columns. The bottom ends of the multiple vertical support columns are connected to the multiple rigid connecting chassis. The bottom ends are for fixing to the inside of the pressure hull of the underwater vehicle body. Figure 3 As shown, the high-rigidity frame 1 may include four parallel vertical support columns 11, three parallel short horizontal bars 12a, two parallel long horizontal bars 12b, and two rigid connecting bases 10. The four vertical support columns 11 and the five horizontal bars form a cuboid structure. The five horizontal bars include three short horizontal bars 12a and two long horizontal bars 12b, and all five horizontal bars are connected to the top of the four vertical support columns 11. The bottom ends of the two vertical support columns 11 connected to the same short horizontal bar are connected to a rigid connecting base 10.
[0045] In some embodiments, the rigid connection chassis is used to fix the high-rigidity frame inside the pressure hull of the underwater vehicle body. The rigid connection chassis 10 can have an arc-shaped contact surface, which can be fully fitted to the inner side of the thin wall. The mounting point is mainly located at the load-bearing structure of the underwater vehicle body to avoid interfering with the vibration characteristics of the thin wall to be tested.
[0046] In some embodiments, the vibration displacement measuring device further includes two inclined mounting surfaces 13, which are fixed to the top of both sides of the high rigidity frame by an adjustable lateral moving rod 7 and a vertical telescopic rod 6, respectively. The two inclined mounting surfaces 12 are used to fix the camera 2 and the stripe projection device 3, respectively.
[0047] Specifically, the vibration displacement measuring device also includes fixing bolts 8, which are used to fix the adjustable lateral moving rod 7 and the vertical telescopic rod 6 to the crossbars at the top of both sides of the high rigidity frame.
[0048] The inclined mounting surface can be at a preset angle to the plane 9 of the thin-walled skin to be measured. This allows the optical measurement components to form a triangulation optical path with the thin-walled skin plane 9 under test. When the thin-walled skin plane 9 of the underwater vehicle vibrates, the camera can capture a deformed image of the reflected fringes. The degree of fringe deformation is approximately linearly amplified by the minute displacement of the mirror vibration, and the amplification factor depends on the distance between the camera and the light source, thus realizing non-contact triangulation measurement of the external thin-walled skin.
[0049] In this embodiment, an embedded installation is adopted, placing the stripe projection device, camera, and high-rigidity frame as a whole within the protective environment of the underwater vehicle, without altering the vehicle's external shape. Optical non-contact measurement technology is used to solve the problem of installing contact sensors on thin-walled structures, achieving high-sensitivity capture of minute vibrations. Powered by the mothership and sharing data, non-contact, long-term, and stable monitoring of minute vibrations on the thin-walled surface of the underwater vehicle is achieved without changing its external aerodynamic shape. By observing the deformation pattern caused by the reflection of vibrations from the specular surface of the thin-walled skin illuminated by the stripe projection device, the entire thin-walled vibration mode is monitored.
[0050] The embodiments of this application provide a theoretical explanation of the above measurement method through the following content: like Figure 4 As shown, Figure 4 This is a theoretical illustration of the vibration displacement measurement method provided in this application embodiment. The optical center of the fringe projection device and the optical center of the camera form a fixed baseline distance d. The fringe projection device projects an undeformed fringe grating (e.g., ... Figure 4 Medium stripe pattern a). For example Figure 4As shown in the geometric details, when the skin surface is in the reference position, light shines on point R and is imaged by the camera (such as Figure 4 the reflected fringe pattern b). When the skin is stimulated to produce a small out-of-plane displacement h, the same light shines on point s. From the camera's perspective, this is equivalent to the observation point moving from R to R' on the reference plane, resulting in a lateral displacement s. On the premise of small vibration h << L, using the geometric similarity relationship, we can get s = dh / L.
[0051] The light intensity distribution I(x, y) of the fringe image captured by the camera can usually be expressed as a cosine function form with background and modulation: ; where (x, y) are the pixel coordinates of the camera sensor; A(x, y) represents the background light intensity; B(x, y) represents the fringe contrast (modulation amplitude); is the total phase value corresponding to this pixel point. When there is no vibration, the image has an initial carrier phase , which is determined by the inherent frequency of the projected fringe grating (for example ). When the above-mentioned lateral displacement s occurs on the thin-walled skin to be measured, it directly causes the phase shift of the fringes in the image, and the additional phase change is: .
[0052] By联立, it can be known that the phase change is proportional to the vibration displacement: ; where k is the system displacement sensitivity coefficient. Therefore, in the vibration state, the image intensity captured by the camera becomes: ; The specific manifestation is as Figure 4 shown. The camera receives the deformed fringe grating, reads the phase of the deformed fringe grating, and combines the calibrated k to accurately calculate the small vibration displacement h on the surface of the thin-walled skin to be measured.
[0053] To better implement the above method, the embodiment of the present application provides a processor. Refer to Figure 5 , Figure 5 which is the structural block diagram of a processor provided by the embodiment of the present application. As Figure 5 shown, the processor 500 can specifically include the following: The first acquisition module 501 is used to acquire a reflected stripe image captured by a camera located inside the pressure hull of the underwater vehicle body; wherein, the reflected stripe image is an image captured by the camera of the stripe pattern reflected by the thin-walled skin under test when a stripe projection device located inside the pressure hull of the underwater vehicle body projects a stripe pattern onto the thin-walled skin under test that has been mirrored outside the underwater vehicle. The second acquisition module 502 is used to acquire the light intensity distribution of each pixel in the reflective stripe image; The third acquisition module 503 is used to acquire the background light intensity, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient of each pixel in the reflective stripe image. The displacement calculation module 504 is used to substitute the light intensity distribution of the striped image at each pixel, the background light intensity, the stripe contrast, the initial carrier phase, and the system displacement sensitivity coefficient into the cosine function formula of the light intensity distribution of the striped image to obtain the vibration displacement corresponding to each target point on the thin-walled skin under test; where the target point is the point corresponding to the pixel on the thin-walled skin under test, and the cosine function formula is as follows: Let (x, y) represent the camera pixel coordinates of the pixel, I(x, y) represent the stripe image light intensity distribution of the pixel, A(x, y) represent the background light intensity of the pixel, and B(x, y) represent the stripe contrast of the pixel. denoted by , where k represents the initial carrier phase corresponding to the pixel, h represents the system displacement sensitivity coefficient, and h represents the vibration displacement.
[0054] In some embodiments, the third acquisition module 503 is further configured to: acquire the fixed baseline distance between the optical center of the stripe projection device and the optical center of the camera, the vertical distance between the stripe projection device and the plane of the thin-walled skin to be measured, and the natural frequency of the stripe pattern projected by the stripe projection device onto the thin-walled skin to be measured; substitute the fixed baseline distance, vertical distance, and natural frequency into the system displacement sensitivity coefficient calculation formula to obtain the system displacement sensitivity coefficient; wherein, the system displacement sensitivity coefficient calculation formula is: , Indicates the natural frequency. L represents the fixed baseline distance, and L represents the vertical distance.
[0055] In some embodiments, the formula for calculating the initial carrier phase of a pixel in the third acquisition module 503 described above is as follows: ; Where (x, y) represents the camera pixel coordinates of the pixel. This represents the initial carrier phase of the pixel. This indicates the natural frequency of the stripe pattern projected by the stripe projection device onto the thin-walled skin under test.
[0056] The processor 500 provided in this application embodiment can execute the technical solution shown in the above method embodiment. Its implementation principle and beneficial effects are similar, and will not be repeated here.
[0057] Figure 6 An internal structural diagram of a computer device in one embodiment is shown. This computer device can specifically be a terminal or a server. Figure 6 As shown, the computer device includes a processor, memory, and a network interface connected via a system bus. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and may also store a computer program that, when executed by the processor, enables the processor to implement an age recognition method. The internal memory may also store a computer program that, when executed by the processor, enables the processor to implement the age recognition method. Those skilled in the art will understand that... Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0058] In one embodiment, a computer device is provided, including a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the following steps: Acquire a reflected stripe image captured by a camera located inside the pressure hull of the underwater vehicle; wherein, the reflected stripe image is an image captured by the camera of the stripe pattern reflected by the thin-walled skin under test when a stripe projection device located inside the pressure hull of the underwater vehicle projects a stripe pattern onto the mirrored thin-walled skin under test outside the underwater vehicle. The intensity distribution of the stripe image, background intensity, stripe contrast, and initial carrier phase of each pixel on the reflected stripe image are obtained, as well as the system displacement sensitivity coefficient is obtained. Substituting the light intensity distribution of the stripe image at each pixel, the background light intensity, the stripe contrast, the initial carrier phase, and the system displacement sensitivity coefficient into the cosine function formula for the light intensity distribution of the stripe image, the vibration displacement corresponding to each target point on the thin-walled skin under test is obtained; where the target point is the point corresponding to the pixel on the thin-walled skin under test, and the cosine function formula is: Let (x, y) represent the camera pixel coordinates of the pixel, I(x, y) represent the stripe image light intensity distribution of the pixel, A(x, y) represent the background light intensity of the pixel, and B(x, y) represent the stripe contrast of the pixel. denoted by , where k represents the initial carrier phase corresponding to the pixel, k represents the system displacement sensitivity coefficient, and h represents the vibration displacement.
[0059] In one embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, causes the processor to perform the following steps: Acquire a reflected stripe image captured by a camera located inside the pressure hull of the underwater vehicle; wherein, the reflected stripe image is an image captured by the camera of the stripe pattern reflected by the thin-walled skin under test when a stripe projection device located inside the pressure hull of the underwater vehicle projects a stripe pattern onto the mirrored thin-walled skin under test outside the underwater vehicle. The intensity distribution of the stripe image, background intensity, stripe contrast, and initial carrier phase of each pixel on the reflected stripe image are obtained, as well as the system displacement sensitivity coefficient is obtained. Substituting the light intensity distribution of the stripe image at each pixel, the background light intensity, the stripe contrast, the initial carrier phase, and the system displacement sensitivity coefficient into the cosine function formula for the light intensity distribution of the stripe image, the vibration displacement corresponding to each target point on the thin-walled skin under test is obtained; where the target point is the point corresponding to the pixel on the thin-walled skin under test, and the cosine function formula is: Let (x, y) represent the camera pixel coordinates of the pixel, I(x, y) represent the stripe image light intensity distribution of the pixel, A(x, y) represent the background light intensity of the pixel, and B(x, y) represent the stripe contrast of the pixel. denoted by , where k represents the initial carrier phase corresponding to the pixel, k represents the system displacement sensitivity coefficient, and h represents the vibration displacement.
[0060] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.
[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0062] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims. Please enter the specific implementation details.
Claims
1. A method for measuring vibration displacement, characterized in that, The method includes: Acquire a reflected stripe image captured by a camera located inside the pressure hull of the underwater vehicle body; wherein, the reflected stripe image is an image captured by the camera of the stripe pattern reflected by the thin-walled skin under test when a stripe projection device located inside the pressure hull of the underwater vehicle body projects a stripe pattern onto the mirrored thin-walled skin under test outside the underwater vehicle. The intensity distribution of the stripe image, background intensity, stripe contrast, initial carrier phase, and system displacement sensitivity coefficient of each pixel on the reflected stripe image are obtained. Substituting the light intensity distribution of the stripe image at each pixel, the background light intensity, the stripe contrast, the initial carrier phase, and the system displacement sensitivity coefficient into the cosine function formula for the light intensity distribution of the stripe image, the vibration displacement corresponding to each target point on the thin-walled skin under test is obtained; wherein, the target point is the point corresponding to the pixel on the thin-walled skin under test, and the cosine function formula is... Let (x, y) represent the camera pixel coordinates of the pixel, I(x, y) represent the stripe image light intensity distribution of the pixel, A(x, y) represent the background light intensity of the pixel, and B(x, y) represent the stripe contrast of the pixel. denoted by , where k represents the initial carrier phase corresponding to the pixel, k represents the system displacement sensitivity coefficient, and h represents the vibration displacement.
2. The method according to claim 1, characterized in that, The acquisition of the system displacement sensitivity coefficient includes: The fixed baseline distance between the optical center of the stripe projection device and the optical center of the camera, the vertical distance between the stripe projection device and the plane of the thin-walled skin under test, and the natural frequency of the stripe pattern projected by the stripe projection device onto the thin-walled skin under test are obtained. Substituting the fixed baseline distance, the vertical distance, and the natural frequency into the system displacement sensitivity coefficient calculation formula, the system displacement sensitivity coefficient is obtained; wherein, the system displacement sensitivity coefficient calculation formula is as follows: , Indicates the inherent frequency, L represents the fixed baseline distance, and L represents the vertical distance.
3. The method according to claim 1, characterized in that, The formula for calculating the initial carrier phase of the pixel is as follows: ； Where (x, y) represents the camera pixel coordinates of the pixel. This represents the initial carrier phase of the pixel. This indicates the inherent frequency of the stripe pattern projected by the stripe projection device onto the thin-walled skin under test.
4. A vibration displacement measuring device, used to implement the method as described in any one of claims 1 to 3, characterized in that, include: A stripe projection device is used to project a stripe pattern onto the mirror-finished thin-walled skin of the underwater vehicle body, when the stripe projection device is embedded inside the pressure hull of the underwater vehicle body. A camera, embedded inside the pressure-resistant hull of the underwater vehicle, is used to acquire images of the reflected stripes from the thin-walled skin under test. A processor, communicatively connected to the camera, is configured to receive the reflective stripe image transmitted by the camera and execute the steps of the method as described in any one of claims 1-3.
5. The apparatus according to claim 4, characterized in that, The vibration displacement measuring device includes: A high-rigidity frame is used to fix the main load-bearing structure on the inner surface of the pressure hull of the underwater vehicle. The stripe projection device and camera are fixed to both sides of the high-rigidity frame by adjustable lateral movement rods and vertical telescopic rods, respectively, to form an optical measurement body with the mirror-finished thin-walled skin of the underwater vehicle. The lateral movement rods and vertical telescopic rods are used to adjust the distance between the camera and the stripe projection device, the angle between the camera and the stripe projection device and the plane of the thin-walled skin to be measured, and the distance between the camera and the stripe projection device and the plane of the thin-walled skin to be measured. The optical center of the stripe projection device and the optical center of the camera form a fixed baseline.
6. The apparatus according to claim 4, characterized in that, The camera in the vibration displacement measuring device is connected to the underwater vehicle through an interface on the back of the camera, and the stripe projection device in the vibration displacement measuring device is connected to the underwater vehicle through an interface on the back of the stripe projection device; the underwater vehicle is used to supply power to the camera and the stripe projection device.
7. The apparatus according to claim 4, characterized in that, The high-rigidity frame includes multiple vertical support columns, multiple horizontal bars, and multiple rigid connecting chassis. The multiple vertical support columns and the multiple horizontal bars form a cuboid structure, and the multiple horizontal bars are all connected to the top of the multiple vertical support columns. The bottom of the multiple vertical support columns is connected to the multiple rigid connecting chassis. The rigid connecting chassis are used to fix the high-rigidity frame inside the pressure hull of the underwater vehicle body.
8. The apparatus according to claim 7, characterized in that, The vibration displacement measuring device also includes two inclined mounting surfaces, which are fixed to the top two sides of the high-rigidity frame by adjustable lateral moving rods and vertical telescopic rods, respectively. The two inclined mounting surfaces are used to fix the camera and the stripe projection device.
9. A computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to perform the steps of the method as claimed in any one of claims 1 to 3.
10. A computer device comprising a memory and a processor, the memory storing a computer program that, when executed by the processor, causes the processor to perform the steps of the method as claimed in any one of claims 1 to 3.