Digital image measurement and analysis system

Abstract

The utility model provides a digital image measurement analysis system, including material testing machine, image acquisition module, lighting module, signal trigger device and computer, material testing machine includes the device base of bottom, image acquisition module is provided the front side of material testing machine, the lighting module is symmetrically distributed on the left and right sides of image acquisition module, signal trigger device is provided with the signal trigger device, and computer is provided with the signal trigger device. The distance between the left and right lighting modules is equal to the width of the device base; the workbench is used for placing the material testing machine, the signal triggering device and the computer; the set height of the image acquisition module and the illumination module does not exceed the total height of the material testing machine and the workbench; the material testing machine, the image acquisition module, the illumination module and the computer are all in wired connection with the signal triggering device. According to the digital image measurement and analysis system, high-quality image acquisition can be realized, the illumination condition is controllable, and high-precision real-time linkage among the modules can be realized in cooperation with the signal triggering device.

Description

Technical Field

[0001] This utility model relates to the field of digital image detection technology, and in particular to a digital image measurement and analysis system. Background Technology

[0002] In the field of materials mechanical property research, digital image measurement and analysis systems are widely used due to their advantages such as non-contact and full-field strain measurement. However, existing systems still have the following limitations: 1. The image acquisition module has a single measurement dimension. Most systems use a monocular camera for two-dimensional image acquisition, which can only obtain in-plane displacement information of the material surface. It cannot accurately measure out-of-plane displacement based on the parallax principle, making it difficult to meet the needs of three-dimensional deformation field analysis; 2. The illumination module has insufficient illumination stability and adaptability. Traditional light sources are mostly unilateral or asymmetrical, which easily produce shadows or reflections on the specimen surface. Moreover, it is impossible to flexibly adjust the illumination parameters (such as wavelength and brightness) according to the material's reflectivity (such as the different reflectivities of metals and composite materials), resulting in unstable image acquisition quality and affecting the feature recognition accuracy of digital image correlation (DIC); 3. The synchronization control accuracy between devices is insufficient. Existing triggering mechanisms cannot achieve microsecond-level synchronization of load loading, image acquisition, and light source control, which can easily cause spatiotemporal misalignment between the mechanical data and image sequence at the moment of material deformation, leading to errors in the deformation field analysis results.

[0003] Therefore, this application aims to develop a digital image measurement and analysis system with comprehensive measurement dimensions, controllable lighting conditions, and high synchronization accuracy. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model proposes a digital image measurement and analysis system to solve the aforementioned problems.

[0005] This application proposes a digital image measurement and analysis system, including a material testing machine, an image acquisition module, an illumination module, a signal triggering device, and a computer. The material testing machine includes a base at the bottom. The image acquisition module is located on the front side of the material testing machine, and the illumination modules are symmetrically distributed on the left and right sides of the image acquisition module, with the distance between the left and right illumination modules equal to the width of the base. The system also includes a workbench for placing the material testing machine, the signal triggering device, and the computer. The height of the image acquisition module and the illumination module does not exceed the total height of the material testing machine and the workbench. The material testing machine, the image acquisition module, the illumination module, and the computer are all wiredly connected to the signal triggering device.

[0006] By adopting the above technical solution, the top surface of the device base is used as the experimental plane. The material testing machine applies external loads (including tension, compression, bending, etc.) to the material to be tested. The signal triggering device can realize synchronous control between the devices. When the material testing machine applies external loads to the material, the trigger signal is synchronously transmitted to the image acquisition module and the lighting module to ensure that at the moment the material deforms, the lighting module illuminates the experimental plane with uniform and stable light. The image acquisition module continuously captures high-definition images of the material surface deformation process at a set frame rate. The acquired image data is transmitted to the computer in real time through wired communication.

[0007] Preferably, the total height of the material testing machine and the worktable is H, and the setting height of the image acquisition module and the lighting module is 0.8H to H.

[0008] By adopting the above technical solution, since the height at which the material testing machine applies the load varies depending on the type of load, the height of the image acquisition module and the lighting module needs to be adjusted according to the actual scene. Setting them to 0.8H to H can cover most load application scenarios.

[0009] Preferably, the image acquisition module includes a binocular CCD camera and a camera bracket. The binocular CCD camera is detachably connected to the top of the camera bracket, and the binocular CCD camera is located on the front central axis of the material testing machine.

[0010] By adopting the above technical solutions, the binocular CCD camera achieves accurate calculation of the three-dimensional coordinates of feature points on the material surface based on the parallax principle. It can simultaneously acquire in-plane and out-of-plane full component displacements, overcoming the limitation of monocular systems in measuring deformation in the thickness direction. The camera is located on the central axis of the material testing machine, ensuring that the optical axes are parallel and the fields of view are completely overlapping. Combined with a high-precision calibration algorithm, the stereo matching error is controlled to below 0.1 pixels, significantly improving the symmetry and repeatability of the full-field strain measurement. The detachable connection design supports quick switching between cameras with different parameters (such as high-speed and high-resolution models), and is compatible with multiple types of tests such as static tension and dynamic impact. Combined with the microsecond-level synchronous control of the signal triggering device, it achieves precise spatiotemporal alignment between deformation images and load data.

[0011] In a further preferred embodiment, the top of the camera bracket is provided with a horizontal mounting rod that guides left and right sides, and the binocular CCD camera is placed at the midpoint of the horizontal mounting rod.

[0012] By adopting the above technical solution, the left and right guide horizontal mounting rods allow the binocular CCD camera to slide horizontally. This can be adjusted according to the specific experimental scenario. Placing the binocular CCD camera at the midpoint of the horizontal mounting rods is more conducive to aligning it with the front central axis of the material testing machine.

[0013] More preferably, the lighting module includes a first LED light source and a second LED light source, which are symmetrically positioned on both sides of the binocular CCD camera and are detachably connected to the horizontal mounting rod.

[0014] By adopting the above technical solution, the symmetrically distributed LED light sources illuminate evenly from both sides, eliminating shadows and reflections on the surface of the specimen, ensuring clear image acquisition without blind spots, and improving the feature recognition accuracy of digital image correlation methods; the detachable connection supports quick replacement of light sources with different wavelengths and brightness, and is compatible with test materials with different reflective properties such as metals and composite materials.

[0015] More preferably, both the first LED light source and the second LED light source include a light source housing and a light source board placed inside the light source housing, and the surface of the light source board is provided with an LED array composed of a number of LED beads.

[0016] By adopting the above technical solution and using LED arrays as the lighting source, LED arrays have the advantages of being easy to use, highly adaptable, and providing constant lighting. They are suitable for any low-speed (quasi-static) application and can adaptively adjust the color temperature (cool or warm).

[0017] Preferably, it also includes a dimmer for adjusting the light intensity of the lighting module, the dimmer being electrically connected to the lighting module.

[0018] By adopting the above technical solution, the light intensity of the lighting module can be adjusted between 10% and 100% using a dimmer, depending on the different experimental scenarios.

[0019] Preferably, the signal triggering device is a DAQ controller.

[0020] By adopting the above technical solution and using the DAQ controller as the signal triggering core, and relying on its high-precision synchronous triggering capability, the mechanical signals of the material testing machine, the image acquisition timing of the binocular CCD camera, and the control of the lighting module are synchronized in real time, ensuring that the mechanical data and image sequence at the moment of material deformation are strictly aligned in time and space.

[0021] Compared with the prior art, the beneficial effects of this application are as follows:

[0022] The image acquisition module of the digital image measurement and analysis system of this application uses the parallax principle to accurately capture the three-dimensional coordinates of feature points on the material surface, which solves the limitation of monocular systems that cannot measure out-of-plane displacement. The lighting module and image acquisition module can cover most load application scenarios. The lighting module can achieve 10%-100% light intensity adjustment through a dimmer, and the detachable design supports quick replacement of different wavelength light sources, eliminating reflections and shadows on the specimen surface and providing stable lighting conditions for high-quality image acquisition. The DAQ controller, as the signal triggering core, links load loading, image acquisition and light source control in real time with high synchronization accuracy. Attached Figure Description

[0023] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the present invention. Other embodiments and many anticipated advantages of the embodiments will be readily recognized as they become better understood through reference to the following detailed description. Elements in the drawings are not necessarily to scale. The same reference numerals refer to corresponding similar parts.

[0024] Figure 1 This is a schematic diagram of the structure of a digital image measurement and analysis system according to an embodiment of this application;

[0025] Figure 2 This is a schematic diagram of the image acquisition module structure according to a specific embodiment of this application;

[0026] Figure 3a This is a schematic diagram of the installation of a special clamp for compression loads according to a specific embodiment of this application;

[0027] Figure 3b This is a schematic diagram of the installation of a tensile load-specific clamp according to a specific embodiment of this application.

[0028] The meaning of each number in the diagram:

[0029] Material testing machine 01, image acquisition module 02, lighting module 03, signal triggering device 04, computer 05, device base 06, workbench 07, binocular CCD camera 08, camera bracket 09, horizontal mounting rod 10, first LED light source 11, second LED light source 12, light source housing 13, light source board 14, material to be tested 15, column 16, crossbeam 17, first clamp mounting base 18, first clamp 19, second clamp mounting base 20, second clamp 21. Detailed Implementation

[0030] In the following detailed description, reference is made to the accompanying drawings, which form part of the detailed description and illustrate illustrative specific embodiments in which the present invention may be practiced. In this regard, directional terms such as “top,” “bottom,” “left,” “right,” “up,” “down,” etc., are used with reference to the orientation of the described figures. Because components of the embodiments can be positioned in several different orientations, directional terms are used for illustrative purposes and are by no means limiting. It should be understood that other embodiments may be utilized or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description should not be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

[0031] This application proposes a digital image measurement and analysis system. Figure 1 A schematic diagram of the structure of a digital image measurement and analysis system according to an embodiment of this application is shown, such as... Figure 1 As shown, the system includes a material testing machine 01, an image acquisition module 02, an illumination module 03, a signal triggering device 04, and a computer 05. The material testing machine 01 includes a base 06 at the bottom. The image acquisition module 02 is located on the front side of the material testing machine 01. The illumination modules 03 are symmetrically distributed on the left and right sides of the image acquisition module 02, and the distance between the left and right illumination modules 03 is equal to the width of the base 06. The system also includes a workbench 07 for placing the material testing machine 01, the signal triggering device 04, and the computer 05. The height of the image acquisition module 02 and the illumination module 03 does not exceed the total height of the material testing machine 01 and the workbench 07. The material testing machine 01, the image acquisition module 02, the illumination module 03, and the computer 05 are all wired to the signal triggering device 04. The wiring connecting the devices is not shown in the figure.

[0032] Preferably, the total height of the material testing machine and the worktable is H, and the setting height of the image acquisition module and the lighting module is 0.8H to H.

[0033] Specifically, the area above the top surface of the device base 06 is the load application space of the material testing machine 01. Therefore, the setting width of the lighting module 03 can cover all types of load application scenarios. Since the load application height of the material testing machine 01 varies depending on the type of load applied, the setting height of the image acquisition module 02 and the lighting module 03 needs to be adjusted according to the actual scenario. Setting it to 0.8H to H can cover most load application scenarios.

[0034] Preferably, the signal triggering device 04 is a DAQ controller. Using the DAQ controller as the core of the signal triggering, it can synchronize the mechanical signals of the material testing machine 01, the image acquisition timing of the image acquisition module 02, and the control of the lighting module 03 in real time with its high-precision synchronous triggering capability, so as to ensure that the mechanical data of the material deformation moment is strictly aligned with the image sequence in time and space.

[0035] The digital image measurement and analysis system of this application requires calibration before use. It uses a dedicated calibration target as a reference object, which is mainly divided into two series of calibration target types: single-sided / double-sided ultra-high precision ceramic target (SS / DS-VHP-CE), which is suitable for FoV of 1*1mm to 80*80mm, and double-sided high precision aluminum honeycomb target (DS-HP-AH), which is suitable for FoV of 80*80mm to 1000*1000mm.

[0036] Figure 2 A schematic diagram of an image acquisition module structure according to a specific embodiment of this application is shown, such as... Figure 1-2 As shown, the image acquisition module 02 includes a binocular CCD camera 08 and a camera bracket 09. The top of the binocular CCD camera 08 is detachably connected to the top of the camera bracket 09, and the binocular CCD camera 08 is located on the front central axis of the material testing machine 01.

[0037] Specifically, the binocular CCD camera 08 in this embodiment has a resolution of 1920*1200 pixels, a maximum frame rate of 165fps at full resolution, is based on USB 3.0, has a maximum bandwidth of 5Gbit, and supports lenses with different focal lengths. The binocular vision uses the parallax principle to accurately calculate the three-dimensional coordinates of feature points on the material surface, and can simultaneously acquire in-plane and out-of-plane full component displacements, overcoming the limitation of monocular systems in measuring deformation in the thickness direction. The camera is located on the central axis of the material testing machine 01, ensuring that the optical axes are parallel and the fields of view are completely overlapping. Combined with a high-precision calibration algorithm, the stereo matching error is controlled to below 0.1 pixels, significantly improving the symmetry and repeatability of the full-field strain measurement. The detachable connection design supports quick switching between cameras with different parameters (such as high-speed and high-resolution models), is compatible with multiple types of tests such as static tension and dynamic impact, and, combined with the microsecond-level synchronous control of the signal triggering device 04, achieves precise spatiotemporal alignment between deformation images and load data.

[0038] Preferably, the top of the camera bracket 09 is provided with a horizontal mounting rod 10 for left and right guidance. The binocular CCD camera 08 is placed at the midpoint of the horizontal mounting rod 10. The horizontal mounting rod 10 for left and right guidance allows the binocular CCD camera 08 to slide in the horizontal direction. It can be adjusted according to the specific experimental scenario. Placing the binocular CCD camera 08 at the midpoint of the horizontal mounting rod 10 is more conducive to aligning it with the front central axis of the material testing machine 01.

[0039] Preferably, the lighting module 03 includes a first LED light source 11 and a second LED light source 12. The first LED light source 11 and the second LED light source 12 are symmetrically placed on both sides of the binocular CCD camera 08 and are detachably connected to the horizontal mounting rod 10.

[0040] Specifically, the horizontal mounting rod 10 is also provided with a horizontal mounting groove, and the binocular CCD camera 08, the first LED light source 11, and the second LED light source 12 can be locked at any point in the mounting groove.

[0041] Specifically, both the first LED light source 11 and the second LED light source 12 include a light source housing 13 and a light source plate 14 placed inside the light source housing 13. The surface of the light source plate 14 is provided with an LED array composed of several LED beads. The LED light sources, which are symmetrically distributed from the left and right, illuminate the specimen surface evenly from both sides, eliminating shadows and reflections, ensuring clear image acquisition without blind spots, and improving the feature recognition accuracy of digital image correlation method.

[0042] In this embodiment, the LED array consists of 156 white LED beads and can be switched to various color temperature settings from cool (3200°K) to warm (5600°K).

[0043] Preferably, it also includes a dimmer (not shown in the figure) for adjusting the light intensity of the lighting module 03. The dimmer is electrically connected to the lighting module 03. Specifically, the dimmer is connected to the first LED light source 11 and the second LED light source 12, and the light intensity of the two is adjusted between 10% and 100% using the dimmer.

[0044] Furthermore, to adapt to different load application scenarios, the material testing machine 01 can be equipped with different fixtures. The following examples illustrate compressive load and tensile load scenarios. Figure 3a A schematic diagram of the installation of a special clamp for compression loads according to a specific embodiment of this application is shown. Figure 3b A schematic diagram of the installation of a tensile load-specific clamp according to a specific embodiment of this application is shown, such as... Figure 1-3b As shown, the material testing machine 01 also includes columns 16 that are symmetrically distributed on the left and right sides and perpendicular to the top surface of the device base 06. A horizontal beam 17 is provided between the left and right columns 16. The two ends of the beam 17 are slidably connected to the columns 16 on both sides. In this embodiment, the inner side of the column 16 is provided with a vertical guide groove for installing a vertical slide rail. The two ends of the beam 17 can be slidably connected to the slide rail by a slider. The drive source for driving the beam 17 to move along the slide rail can be a linear motor.

[0045] Specifically, the spacing between the lighting modules 03 is equal to the surface spacing between the opposing columns 16 on both sides.

[0046] A first clamp mounting base 18 is provided in the middle of the crossbeam 17, and a first clamp 19 is detachably mounted on the bottom surface of the first clamp mounting base 18.

[0047] Specifically, Figure 3aIn the first clamp 19, a special clamp for compression load, the material to be tested 15 is placed directly on the top surface of the device base 06, the control beam 17 is lowered, and thus the end of the first clamp 19 is subjected to a downward compression load.

[0048] Preferably, the top surface of the device base 06 is provided with a detachable second clamp mounting seat 20 at the position corresponding to the first clamp mounting seat 18, and the top surface of the second clamp mounting seat 20 is detachably mounted with a second clamp 21.

[0049] Specifically, in Figure 3b In the process, the first clamp 19 and the second clamp 21 are both special clamps for tensile loads. The first clamp 19 and the second clamp 21 are used to clamp the upper and lower sides of the material to be tested 15 respectively, control the crossbeam 17 to rise, and then apply a tensile load to the material to be tested 15.

[0050] Obviously, those skilled in the art can make various modifications and changes to the embodiments of this utility model without departing from the spirit and scope of this utility model. In this way, this utility model is also intended to cover such modifications and changes if they fall within the scope of the claims of this utility model and their equivalents. The word "comprising" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are described in mutually different dependent claims does not indicate that a combination of these measures cannot be used for profit. Any reference numerals in the claims should not be considered as limiting the scope.

Claims

1. A digital image measurement and analysis system, characterized in that, The device includes a material testing machine, an image acquisition module, an illumination module, a signal triggering device, and a computer. The material testing machine includes a base at the bottom. The image acquisition module is located on the front side of the material testing machine, and the illumination modules are symmetrically distributed on the left and right sides of the image acquisition module, with the distance between the left and right illumination modules equal to the width of the base. It also includes a workbench for placing the material testing machine, the signal triggering device, and the computer. The height of the image acquisition module and the illumination module does not exceed the total height of the material testing machine and the workbench. The material testing machine, the image acquisition module, the illumination module, and the computer are all wiredly connected to the signal triggering device.

2. The measurement and analysis system according to claim 1, characterized in that, The total height of the material testing machine and the worktable is H, and the height of the image acquisition module and the lighting module is 0.8H to H.

3. The measurement and analysis system according to claim 1, characterized in that, The image acquisition module includes a binocular CCD camera and a camera bracket. The binocular CCD camera is detachably connected to the top of the camera bracket, and the binocular CCD camera is located on the front central axis of the material testing machine.

4. The measurement and analysis system according to claim 3, characterized in that, The top of the camera bracket is provided with a horizontal mounting rod for left and right guidance, and the binocular CCD camera is placed at the midpoint of the horizontal mounting rod.

5. The measurement and analysis system according to claim 4, characterized in that, The lighting module includes a first LED light source and a second LED light source, which are symmetrically positioned on both sides of the binocular CCD camera and are detachably connected to the horizontal mounting rod.

6. The measurement and analysis system according to claim 5, characterized in that, Both the first LED light source and the second LED light source include a light source housing and a light source plate placed inside the light source housing. The surface of the light source plate is provided with an LED array composed of a number of LED beads.

7. The measurement and analysis system according to claim 1, characterized in that, It also includes a dimmer for adjusting the light intensity of the lighting module, the dimmer being electrically connected to the lighting module.

8. The measurement and analysis system according to claim 1, characterized in that, The signal triggering device is a DAQ controller.

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