Three-dimensional displacement strain measurement method and device, computer equipment and storage medium

Abstract

The invention relates to the technical field of strain measurement, and discloses a three-dimensional displacement strain measurement method and device, computer equipment and a storage medium, and the method comprises the steps: obtaining a 3D point cloud of a measured object when a testing machine applies a load to the measured object, the 3D point cloud being obtained through the three-dimensional shape measurement based on a structured light device and a structured light technology, the measured object is placed in a testing machine after being sprayed with speckles, the position of the structured light equipment is set based on the position of the measured object, then the full-field displacement of the measured object in the 2D image is obtained, then the pixels of the 2D image are aligned with the 3D point cloud based on the full-field displacement in the 2D image, the full-field displacement of the 3D point cloud is obtained, and the full-field displacement of the 3D point cloud is calculated. And finally, calculating based on the full-field displacement of the 3D point cloud to obtain the full-field strain of the 3D point cloud.The three-dimensional displacement strain measurement method can simultaneously meet high-precision, high-resolution and real-time three-dimensional displacement strain measurement.

Description

Technical Field

[0001] The present invention relates to the field of strain measurement technology, and in particular to a three-dimensional displacement strain measurement method, device, computer equipment and storage medium. Background Art

[0002] Measurement is the premise of digital processing. Therefore, how to quickly obtain full-field, high-precision, and high-resolution three-dimensional surface data of the test piece has become a key issue in the path to intelligent manufacturing. Due to the emergence of various new materials in recent years, further obtaining the characteristics of the full-field three-dimensional spatial position of various materials and complex structures in high-end precision manufacturing under the force process and changing with time, and realizing deformation and strain analysis, can more scientifically, accurately, and timely reconstruct and analyze the mechanical properties of materials and structures, and correctly and scientifically explain the causes and mechanisms of deformation. However, the most successful three-dimensional digital image correlation method (Digital Image Correlation, DIC) in the field of experimental mechanics is difficult to simultaneously achieve high-precision, high-resolution real-time measurement of displacement and strain.

[0003] Three-dimensional DIC technology is also called binocular stereo DIC. This technology uses binocular matching algorithm to reconstruct three-dimensional morphology, and the displacement and strain information are further tracked by time matching under a single perspective. The reason why three-dimensional DIC technology is difficult to achieve high-precision, high-resolution and real-time full-field displacement and strain measurement at the same time is that its morphology reconstruction is based on the binocular matching algorithm. Under the condition that the camera focal length and the distance from the object to the camera are determined, high precision, high resolution and real-time performance cannot be taken into account in the matching algorithm. The specific reasons are as follows: First, the larger the camera baseline distance, the higher the accuracy in the Z-axis direction, but the large baseline distance will lead to a smaller field of view, which will also lead to a decrease in matching accuracy, and even sub-region mismatching, and it is impossible to complete iterative convergence, resulting in reconstruction failure; second, to provide a higher-resolution image, but because the matching algorithm usually has a huge amount of calculation, three-dimensional DIC needs to complete stereo matching and time matching, which poses a great challenge to real-time performance; third, if real-time performance and high resolution are guaranteed, the selection of the matching algorithm needs to blur the details of the object to be measured. In this way, although three-dimensional morphology and deformation information can be obtained at the same time, the accuracy cannot be well guaranteed. Summary of the invention

[0004] Based on this, it is necessary to propose a three-dimensional displacement strain measurement method, device, computer equipment and storage medium to address the technical problem that the three-dimensional displacement strain measurement effect of the existing technology is poor.

[0005] In a first aspect, a three-dimensional displacement strain measurement method is provided, the method comprising:

[0006] When the test machine applies a load to the object to be tested, a 3D point cloud of the object to be tested is obtained, wherein the 3D point cloud is obtained by performing three-dimensional shape measurement based on a structured light device and structured light technology, the object to be tested is placed in the test machine after being sprayed with speckles, and the position of the structured light device is set based on the position of the object to be tested;

[0007] Obtain the full-field displacement of the object being measured in the 2D image;

[0008] Based on the full-field displacement in the 2D image, aligning the 2D image pixels with the 3D point cloud to obtain the full-field displacement of the 3D point cloud;

[0009] The full-field strain of the 3D point cloud is obtained by calculating the full-field displacement of the 3D point cloud.

[0010] In a second aspect, a three-dimensional displacement strain measurement device is provided, the device comprising:

[0011] A first acquisition module is used to acquire a 3D point cloud of the object under test when the test machine applies a load to the object under test, wherein the 3D point cloud is obtained by performing three-dimensional shape measurement based on a structured light device and structured light technology, the object under test is placed in the test machine after being sprayed with speckles, and the position of the structured light device is set based on the position of the object under test;

[0012] The second acquisition module is used to acquire the full-field displacement of the measured object in the 2D image;

[0013] an alignment module, configured to align the 2D image pixels with the 3D point cloud based on the full-field displacement in the 2D image, so as to obtain the full-field displacement of the 3D point cloud;

[0014] The calculation module is used to calculate the full-field displacement of the 3D point cloud to obtain the full-field strain of the 3D point cloud.

[0015] In a third aspect, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned three-dimensional displacement strain measurement method when executing the computer program.

[0016] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned three-dimensional displacement strain measurement method are implemented.

[0017] The three-dimensional displacement strain measurement method proposed in the present invention obtains the 3D point cloud of the object to be measured when the testing machine applies a load to the object to be measured, wherein the 3D point cloud is obtained by performing three-dimensional morphology measurement based on a structured light device and structured light technology, the object to be measured is placed in the testing machine after spraying speckle, the position of the structured light device is set based on the position of the object to be measured, and then the full-field displacement of the object to be measured in the 2D image is obtained, and then based on the full-field displacement in the 2D image, the 2D image pixels are aligned with the 3D point cloud to obtain the full-field displacement of the 3D point cloud, and finally based on the full-field displacement of the 3D point cloud, the full-field strain of the 3D point cloud is calculated, and the present invention can simultaneously meet the three-dimensional displacement strain measurement requirements of high precision, high resolution and real-time performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] in:

[0020] Figure 1 A diagram showing an application environment of a three-dimensional displacement strain measurement method in an embodiment;

[0021] Figure 2 is a flow chart of a three-dimensional displacement strain measurement method in one embodiment;

[0022] Figure 3 A schematic diagram of a Gray code encoding strategy of a fringe translation method of a three-dimensional displacement strain measurement method in one embodiment;

[0023] Figure 4 It is a schematic diagram of the timing matching principle based on DIC of the fringe translation method of the three-dimensional displacement strain measurement method in one embodiment;

[0024] Figure 5 A TCPE principle schematic diagram of a three-dimensional displacement strain measurement method in one embodiment;

[0025] Figure 6 is a structural block diagram of a three-dimensional displacement strain measurement device in one embodiment;

[0026] Figure 7 is a structural block diagram of a computer device in one embodiment;

[0027] Figure 8 It is a structural block diagram of a computer device in another embodiment. DETAILED DESCRIPTION

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of the present application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The three-dimensional displacement strain measurement method provided by the embodiment of the present invention can be applied in Figure 1In the measurement system, after the tested object is sprayed with speckle, it is ensured that it can start measuring in the optimal working space of the structured light three-dimensional reconstruction device. The three-dimensional reconstruction module, the timing matching module, and the displacement strain measurement module are run on the PC. Before starting the measurement, the tested object is first sprayed with speckle, and the tested object is placed in the test machine after the speckle is completely dried. After the structured light working distance is adjusted to the optimal working distance, the structured light device is turned on to adjust the parameters. After the structured light device works stably, the test machine applies a load to the tested object. The measurement uses the structured light technology to perform three-dimensional morphology measurement to obtain high-precision and real-time point cloud data; while the point cloud is obtained, the timing matching module obtains the full-field displacement of the tested object in the 2D image in parallel. The timing matching module uses the image of the tested object with speckle obtained when the projector projects a full-white image, and obtains the displacement of each pixel in the 2D image and its surrounding interpolation through correlation matching. Then the displacement strain measurement module aligns the 2D image pixels with the 3D point cloud based on the full-field displacement in the 2D image, and can obtain the displacement of each 3D point at different times, that is, the full-field displacement of the 3D point cloud. The 3D point cloud is triangulated and the strain of each triangular element is calculated and finally accumulated to obtain the full-field strain of all point clouds.

[0032] See also Figure 2 As shown, Figure 2 A schematic flow chart of a three-dimensional displacement strain measurement method provided in an embodiment of the present invention includes the following steps:

[0033] Step S101: when the test machine applies a load to the object to be tested, a 3D point cloud of the object to be tested is obtained, wherein the 3D point cloud is obtained by performing three-dimensional shape measurement based on a structured light device and structured light technology, the object to be tested is placed in the test machine after being sprayed with speckles, and the position of the structured light device is set based on the position of the object to be tested;

[0034] In this embodiment, preparation work must be done first. The main contents of the preparation work include: spraying speckle, equipment layout, and parameter setting. The purpose of spraying speckle on the object to be measured is to achieve good timing matching, so the sprayed speckle is required to have high contrast, reasonable size, random pattern, and a duty cycle close to 50%. In terms of equipment layout, the object to be measured is required to be near the optimal working distance of the structured light device. Set the appropriate exposure time in the software to make the camera exposure normal, and set a reasonable sub-area size and matching step size to achieve the best matching effect and the fastest convergence speed.

[0035] As an example, a 3D point cloud of the object under test is obtained by a 3D reconstruction module. The 3D reconstruction module chooses to use mature structured light. Different from the coding method of projecting positive stripes and line patterns, the present invention selects a coding pattern based on the edge of the stripes to provide a more robust and higher-precision 3D shape reconstruction result. The 3D reconstruction method based on structured light is to replace one camera in the traditional binocular vision method with a projector, and use the template projected by the codec projector to solve the corresponding point matching problem that is difficult to solve in binocular vision. The calibrated camera and projector and the triangulation principle can be used to obtain the three-dimensional information of the object. Compared with traditional sinusoidal images, the stripe edge information can be better preserved than the intensity of a single pixel, and each strip edge point is assigned a unique coding word. The problem of periodic ambiguity is well solved by combining local and global Gray code values. Figure 3 As shown in the figure, the 9 global Gray code images above divide the surface of the object to be tested into 256 sub-areas, and the strip pattern with a width of 4 pixels below is moved three times in each sub-area to encode the position. The strip edges of the moving pattern will be detected and encoded with higher accuracy. The entire encoded image is about 12-18 images, so to achieve a 3D scanning speed of 30fps, the output frequency of the camera and projection module must be greater than 500HZ.

[0036] In one embodiment, the structured light device adopts a Gray code encoding strategy of a fringe translation method.

[0037] Step S102: obtaining the full-field displacement of the object under test in the 2D image;

[0038] In one embodiment, the step of obtaining the full-field displacement of the object under test in the 2D image includes: based on the DIC algorithm, using the projector in the structured light device to obtain an image of the object under test with speckles when projecting a full-white image, and obtaining the displacement of each pixel in the 2D image and its surrounding interpolation through correlation matching to obtain the full-field displacement in the 2D image.

[0039] In one embodiment, the full-field displacement of the object under test in the 2D image is obtained by a timing matching module. The timing matching module uses the image of the object under test with speckles obtained when the projector projects a full white image, and obtains the displacement of each pixel in the 2D image and its surrounding interpolation through correlation matching. The input of this module is the image of the object under test with speckles captured when the structured light projects a full white image. Specifically, the DIC algorithm can be used to track the position of a point on the reference image on the deformed image. The principle diagram is shown in FIG. Figure 4 For any point p(u,v) on the reference image, the Zero-mean Normalized Sum of Squared Differences (ZNSSD) algorithm is used, which minimizes the difference between the corresponding sub-intervals. The calculation formula is as follows:

[0040]

[0041] Where: Ω is the computational sub-region in the reference image, I R (u,v) and I C (u′,v′) represents the intensity value of the selected point in the reference image and the current image, and is the mean of the corresponding sub-region, p = (u, v, u x ,u y ,v x ,v y ) represents the deformation function, which determines the shape function of the corresponding point in the reference image and the current image. Considering the computational efficiency, the first-order deformation function is selected, and the formula is as follows:

[0042]

[0043] Step S103: based on the full-field displacement in the 2D image, align the 2D image pixels with the 3D point cloud to obtain the full-field displacement of the 3D point cloud;

[0044] Step S104: Calculate based on the full-field displacement of the 3D point cloud to obtain the full-field strain of the 3D point cloud.

[0045] In one embodiment, the point cloud is triangulated to obtain triangular units, and for each triangular unit, the full-field strain of the 3D point cloud is determined based on the use of a Triangular Cosserat Point Elements algorithm and the full-field displacement of the 3D point cloud.

[0046] Specifically, after obtaining the displacement field of the 3D point cloud, the point cloud is triangulated and the deformation gradient tensor is calculated for each triangular unit using the Triangular Cosserat Point Elements (TCPE) algorithm.

[0047] Assuming that the deformation field in each triangular unit is uniform, the position vectors of the three vertices of the unit in the reference point cloud data can be expressed as: {P1, P2, P3}, and the corresponding three vertex position vectors of the unit in the current point cloud data can be expressed as: {p1, p2, p3}. In addition, the direction vectors of the triangular unit in the reference point cloud and the corresponding triangular unit in the current point cloud can be expressed as: {D1, D2, D3} and {d1, d2, d3}, where D3 and d3 are the normal vectors of the plane where the unit is located, such as Figure 5 , A is the area of ​​the triangular unit

[0048]

[0049] D1×D2·D3=2A(5)

[0050] The reciprocal vector of the unit in the reference point cloud is:

[0051]

[0052] Therefore, the deformation gradient tensor F is:

[0053]

[0054] The left and right Cauchy-Green deformation tensors (C and B), Green-Lagrange and Euler-Almanci strain tensors (E and e) can be calculated as follows:

[0055] C=F T F; B = FF T (8)

[0056]

[0057] See also Figure 5 As shown, in one embodiment, a three-dimensional displacement strain measurement device is provided, the device comprising: a first acquisition module 10, for acquiring a 3D point cloud of the object under test when a test machine applies a load to the object under test, wherein the 3D point cloud is obtained by performing three-dimensional shape measurement based on a structured light device and structured light technology, the object under test is placed in the test machine after being sprayed with speckles, and the position of the structured light device is set based on the position of the object under test;

[0058] A second acquisition module 20 is used to acquire the full-field displacement of the object under test in the 2D image;

[0059] An alignment module 30, configured to align the 2D image pixels with the 3D point cloud based on the full-field displacement in the 2D image to obtain the full-field displacement of the 3D point cloud;

[0060] The calculation module 40 is used to perform calculation based on the full-field displacement of the 3D point cloud to obtain the full-field strain of the 3D point cloud.

[0061] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 6As shown. The computer device includes a processor, a memory, a network interface and a database connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile and / or volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external client via a network connection. When the computer program is executed by the processor, it realizes the functions or steps on the service side of a three-dimensional displacement strain measurement method.

[0062] In one embodiment, a computer device is provided. The computer device may be a client, and its internal structure diagram may be as follows: Figure 7 As shown. The computer device includes a processor, a memory, a network interface, a display screen and an input device connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external server via a network connection. When the computer program is executed by the processor, it realizes the functions or steps of the client side of a three-dimensional displacement strain measurement method.

[0063] In one embodiment, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the following steps are implemented:

[0064] When the test machine applies a load to the object to be tested, a 3D point cloud of the object to be tested is obtained, wherein the 3D point cloud is obtained by performing three-dimensional shape measurement based on a structured light device and structured light technology, the object to be tested is placed in the test machine after being sprayed with speckles, and the position of the structured light device is set based on the position of the object to be tested;

[0065] Obtain the full-field displacement of the object being measured in the 2D image;

[0066] Based on the full-field displacement in the 2D image, aligning the 2D image pixels with the 3D point cloud to obtain the full-field displacement of the 3D point cloud;

[0067] The full-field strain of the 3D point cloud is obtained by calculating the full-field displacement of the 3D point cloud.

[0068] The three-dimensional displacement strain measurement method proposed in the present invention obtains the 3D point cloud of the object to be measured when the testing machine applies a load to the object to be measured, wherein the 3D point cloud is obtained by performing three-dimensional morphology measurement based on a structured light device and structured light technology, the object to be measured is placed in the testing machine after spraying speckle, the position of the structured light device is set based on the position of the object to be measured, and then the full-field displacement of the object to be measured in the 2D image is obtained, and then based on the full-field displacement in the 2D image, the 2D image pixels are aligned with the 3D point cloud to obtain the full-field displacement of the 3D point cloud, and finally based on the full-field displacement of the 3D point cloud, the full-field strain of the 3D point cloud is calculated, and the present invention can simultaneously meet the three-dimensional displacement strain measurement requirements of high precision, high resolution and real-time performance.

[0069] In one embodiment, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0070] When the test machine applies a load to the object to be tested, a 3D point cloud of the object to be tested is obtained, wherein the 3D point cloud is obtained by performing three-dimensional shape measurement based on a structured light device and structured light technology, the object to be tested is placed in the test machine after being sprayed with speckles, and the position of the structured light device is set based on the position of the object to be tested;

[0071] Obtain the full-field displacement of the object being measured in the 2D image;

[0072] Based on the full-field displacement in the 2D image, aligning the 2D image pixels with the 3D point cloud to obtain the full-field displacement of the 3D point cloud;

[0073] The full-field strain of the 3D point cloud is obtained by calculating the full-field displacement of the 3D point cloud.

[0074] The three-dimensional displacement strain measurement method proposed in the present invention obtains the 3D point cloud of the object to be measured when the testing machine applies a load to the object to be measured, wherein the 3D point cloud is obtained by performing three-dimensional morphology measurement based on a structured light device and structured light technology, the object to be measured is placed in the testing machine after spraying speckle, the position of the structured light device is set based on the position of the object to be measured, and then the full-field displacement of the object to be measured in the 2D image is obtained, and then based on the full-field displacement in the 2D image, the 2D image pixels are aligned with the 3D point cloud to obtain the full-field displacement of the 3D point cloud, and finally based on the full-field displacement of the 3D point cloud, the full-field strain of the 3D point cloud is calculated, and the present invention can simultaneously meet the three-dimensional displacement strain measurement requirements of high precision, high resolution and real-time performance.

[0075] It should be noted that the above functions or steps that can be implemented by the computer-readable storage medium or computer device can refer to the relevant descriptions on the server side and the client side in the aforementioned method embodiment. To avoid repetition, they will not be described one by one here.

[0076] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database 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. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0077] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0078] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A three-dimensional displacement strain measurement method, characterized in that: Three-dimensional displacement strain measurement methods include: When the test machine applies a load to the object to be tested, a 3D point cloud of the object to be tested is obtained, wherein the 3D point cloud is obtained by performing three-dimensional shape measurement based on a structured light device and structured light technology, the object to be tested is placed in the test machine after being sprayed with speckles, and the position of the structured light device is set based on the position of the object to be tested; Obtain the full-field displacement of the object being measured in the 2D image; Based on the full-field displacement in the 2D image, aligning the 2D image pixels with the 3D point cloud to obtain the full-field displacement of the 3D point cloud; The full-field strain of the 3D point cloud is obtained by calculating the full-field displacement of the 3D point cloud.

2. The three-dimensional displacement strain measurement method according to claim 1, characterized in that: The step of obtaining the full-field displacement of the object under test in the 2D image comprises: Based on the DIC algorithm, the image of the object with speckles is obtained when the projector in the structured light device projects a full white image. The displacement of each pixel in the 2D image and its surrounding interpolation is obtained through correlation matching to obtain the full-field displacement in the 2D image.

3. The three-dimensional displacement strain measurement method according to claim 1, characterized in that: The structured light device adopts a Gray code encoding strategy of a fringe translation method.

4. The three-dimensional displacement strain measurement method according to claim 1, characterized in that: The step of calculating based on the full-field displacement of the 3D point cloud to obtain the full-field strain of the 3D point cloud comprises: The point cloud is triangulated to obtain triangular units, and for each triangular unit, the full-field strain of the 3D point cloud is determined based on the use of a Triangular Cosserat Point Elements algorithm and the full-field displacement of the 3D point cloud.

5. A three-dimensional displacement strain measurement device, characterized in that: The three-dimensional displacement strain measuring device comprises: A first acquisition module is used to acquire a 3D point cloud of the object under test when the test machine applies a load to the object under test, wherein the 3D point cloud is obtained by performing three-dimensional shape measurement based on a structured light device and structured light technology, the object under test is placed in the test machine after being sprayed with speckles, and the position of the structured light device is set based on the position of the object under test; The second acquisition module is used to acquire the full-field displacement of the measured object in the 2D image; an alignment module, configured to align the 2D image pixels with the 3D point cloud based on the full-field displacement in the 2D image, so as to obtain the full-field displacement of the 3D point cloud; The calculation module is used to calculate the full-field displacement of the 3D point cloud to obtain the full-field strain of the 3D point cloud.

6. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the three-dimensional displacement strain measurement method according to any one of claims 1 to 4 are implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the three-dimensional displacement strain measurement method according to any one of claims 1 to 4 are implemented.

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