Image acquisition system and method for digital image correlation measurement

Abstract

The invention provides an image acquisition system and method for digital image correlation measurement, and relates to the technical field of image processing. The motion execution device comprises an electric tripod lifting mechanism, an electric slewing mechanism, a sliding rail mechanism and a multi-degree-of-freedom motion mechanism; the electric slewing mechanism is rotationally connected to the electric tripod lifting mechanism, the sliding rail mechanism is fixedly connected to the electric slewing mechanism, and the multi-degree-of-freedom movement mechanism is slidably connected to the sliding rail mechanism; the image acquisition device is fixedly connected to the multi-degree-of-freedom movement mechanism; the multi-degree-of-freedom motion mechanism is used for driving the image acquisition device to perform horizontal rotary motion and / or vertical pitching motion; the image acquisition device is used for shooting speckle images on the surface of the sample and transmitting the speckle images to the control device; the control device is used for adjusting motion parameters of the motion execution device according to the speckle image. According to the system, the problem of how to improve the debugging automation degree of the digital image related image acquisition device is solved.

Description

Technical Field

[0001] The present application relates to the field of image processing technology, and in particular to an image acquisition system and method for digital image correlation measurement. Background Art

[0002] The digital image correlation image acquisition device is a device that collects and analyzes the displacement and stress distribution of the surface of an object. During use, it needs to be debugged in advance. The debugging process requires coordination and cooperation among multiple people. The operator at the control end needs to observe the captured image and provide feedback. The operator at the device end needs to manually adjust the posture and position of the image collector according to the captured image.

[0003] This debugging process has many potential inconveniences. Manual debugging requires professionals to invest a lot of time and energy, especially in complex and unconventional test environments. The debugging process is cumbersome and affects work efficiency. Moreover, in a highly automated test environment, frequent manual intervention will reduce the automation level of the entire system, affecting overall work efficiency and process management.

[0004] Therefore, how to improve the degree of automation in debugging digital image-related image acquisition devices is an urgent problem to be solved in this application. Summary of the invention

[0005] The present application provides an image acquisition system and method for digital image correlation measurement, which are used to solve the problem of how to improve the debugging automation level of a digital image correlation image acquisition device.

[0006] In a first aspect, the present application provides an image acquisition system for digital image correlation measurement, comprising: a motion execution device, an image acquisition device, and a control device;

[0007] The motion execution device includes: an electric tripod lifting mechanism, an electric slewing mechanism, a slide rail mechanism and a multi-degree-of-freedom motion mechanism; the electric slewing mechanism is rotatably connected to the electric tripod lifting mechanism, the slide rail mechanism is fixedly connected to the electric slewing mechanism, and the multi-degree-of-freedom motion mechanism is slidably connected to the slide rail mechanism;

[0008] The image acquisition device is fixedly connected to the multi-degree-of-freedom motion mechanism; the multi-degree-of-freedom motion mechanism is used to drive the image acquisition device to perform horizontal rotation movement and / or vertical pitch movement; the image acquisition device is used to capture the speckle image of the sample surface and transmit the speckle image to the control device;

[0009] The control device is used to adjust the motion parameters of the motion execution device according to the speckle image.

[0010] In a possible design, the number of image acquisition devices is two, and the multi-degree-of-freedom motion mechanism includes: two electric fine-tuning pan-tilt platforms;

[0011] Each electric fine-tuning pan / tilt head includes: a horizontal rotation platform, a bending pipe and a vertical tilt platform;

[0012] For any electric fine-tuning pan / tilt, the two ends of the curved pipe are perpendicular to each other, the horizontal rotating platform is slidably connected to the slide rail mechanism, the curved pipe is rotationally connected to the horizontal rotating platform, the vertical pitch platform is rotationally connected to the curved pipe, and the image acquisition device is fixedly installed on the vertical pitch platform.

[0013] In one possible design, the slide rail mechanism includes: a linear slide rail;

[0014] Each horizontal rotating platform comprises a sliding block slidably connected in a linear slide rail.

[0015] In one possible design, the motion execution device further includes: a first laser distance measuring device fixedly mounted on a slider;

[0016] The first laser distance measuring device is used to measure a first distance between the two sliding blocks; wherein the second distance between the two image acquisition devices is determined based on the first distance.

[0017] In one possible design, the motion execution device further includes: a second laser distance measuring device fixedly mounted on the slide rail mechanism;

[0018] The second laser distance measuring device is used to measure a third distance between the slide rail mechanism and the sample; wherein the fourth distance between the system and the sample is determined based on the third distance.

[0019] In one possible design, the electric tripod lifting mechanism includes: a central electric push rod and a plurality of legs;

[0020] The central electric push rod is respectively hinged with each leg, and the electric slewing mechanism is rotatably connected to the electric tripod lifting mechanism;

[0021] The central electric push rod is used to drive the electric rotary mechanism to perform vertical lifting movement.

[0022] In a second aspect, the present application provides an image acquisition method for digital image correlation measurement, comprising:

[0023] Determine the shooting parameters of the image acquisition device according to the shooting requirements of the sample;

[0024] The image acquisition device after adjusting the shooting parameters is used to capture the speckle image on the surface of the sample, and the motion parameters of the motion execution device are adjusted according to the speckle image;

[0025] Displays the speckle image after adjusting the motion parameters.

[0026] In a possible design, the image acquisition device includes an image display and a lens. The shooting parameters of the image acquisition device are determined according to the shooting requirements of the sample, including:

[0027] Determine the frequency of the image display and the focal length of the lens based on the sample's shooting frame rate and field of view requirements;

[0028] The motion execution device includes a second laser ranging device. After determining the shooting parameters of the image acquisition device according to the shooting requirements of the sample, the method further includes:

[0029] Determine the required distance between the system and the sample based on the size of the sample's surface of interest, the image display's field of view, and the lens' focal length;

[0030] According to the second laser distance measuring device, a fourth distance between the system and the sample is determined, and the fourth distance is adjusted according to the required distance.

[0031] In a possible design, the motion execution device includes an electric tripod lifting mechanism, an electric rotation mechanism, a slide mechanism and a multi-degree-of-freedom motion mechanism, and the speckle image is updated in real time;

[0032] According to the speckle image, the motion parameters of the motion execution device are adjusted, including:

[0033] According to the speckle image, performing several of the plurality of adjustment steps until the field of view completely covers the surface of interest;

[0034] Multiple adjustment steps, including:

[0035] Control the electric tripod lifting mechanism to perform vertical lifting movement;

[0036] Control the electric rotary mechanism to perform horizontal rotation movement;

[0037] Controlling the multi-degree-of-freedom motion mechanism to perform horizontal sliding motion on the slide rail mechanism;

[0038] Control the multi-degree-of-freedom motion mechanism to perform horizontal rotational motion;

[0039] Control the multi-degree-of-freedom motion mechanism to perform vertical pitch motion.

[0040] In a possible design, the number of image acquisition devices is two, the multi-degree-of-freedom motion mechanism includes two electric fine-tuning pan-tilt platforms, and the motion execution device also includes a first laser ranging device;

[0041] Control multi-degree-of-freedom motion mechanisms to perform horizontal rotational motion, including:

[0042] Determine a second distance between the two image acquisition devices according to the first laser distance measuring device;

[0043] Determining the horizontal rotation angles of the two electric fine-tuning pan / tilt heads according to the second distance and the adjusted fourth distance;

[0044] According to the respective horizontal rotation angles of the two electric fine-tuning pan-tilt heads, the two electric fine-tuning pan-tilt heads are controlled to perform horizontal rotation movement.

[0045] In a third aspect, the present application provides an image acquisition device for digital image correlation measurement, comprising:

[0046] A parameter determination module, used to determine the shooting parameters of the image acquisition device according to the shooting requirements of the sample;

[0047] An adjustment device module is used to capture a speckle image on the surface of the sample by adjusting the image acquisition device after the shooting parameters are adjusted, and to adjust the motion parameters of the motion execution device according to the speckle image;

[0048] The image display module is used to display the speckle image after the motion parameters are adjusted.

[0049] In a fourth aspect, the present application provides an electronic device, comprising: a processor, and a memory communicatively connected to the processor;

[0050] Memory stores computer-executable instructions;

[0051] The processor executes the computer-executable instructions stored in the memory to implement an image acquisition system and method for digital image correlation measurement in accordance with the first invention and the second invention.

[0052] In a fifth aspect, the present application provides a computer-readable storage medium, which stores computer execution instructions. When the computer execution instructions are executed by a processor, they are used to implement an image acquisition system and method for digital image correlation measurement of the first aspect of the invention and the second aspect of the invention.

[0053] In a sixth aspect, the present application provides a computer program product, including: a computer program, which, when executed by a processor, is used to implement an image acquisition system and method for digital image correlation measurement according to the first aspect of the invention and the second aspect of the invention.

[0054] The present application provides an image acquisition system and method for digital image correlation measurement, wherein the motion execution device comprises: an electric tripod lifting mechanism, an electric rotary mechanism, a slide rail mechanism and a multi-degree-of-freedom motion mechanism; the electric rotary mechanism is rotatably connected to the electric tripod lifting mechanism, the slide rail mechanism is fixedly connected to the electric rotary mechanism, and the multi-degree-of-freedom motion mechanism is slidably connected to the slide rail mechanism; the image acquisition device is fixedly connected to the multi-degree-of-freedom motion mechanism; the multi-degree-of-freedom motion mechanism is used to drive the image acquisition device to perform horizontal rotation and / or vertical pitch motion; the image acquisition device is used to capture the speckle image on the surface of the sample and transmit the speckle image to the control device; the control device is used to adjust the motion parameters of the motion execution device according to the speckle image. The following technical effects are achieved: by controlling the multi-degree-of-freedom motion mechanism, the image acquisition device is adjusted according to the shooting requirements of the image acquisition device; the operation is convenient; the control device obtains the image transmitted by the image acquisition device, and adjusts the motion execution device according to the real-time image to meet the shooting requirements; the cooperation between the motion execution device, the image acquisition device and the control device is used to realize the automatic adjustment of the image acquisition process, so that the work efficiency is improved and the automation degree of the whole system is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0056] Figure 1 A framework diagram of an application scenario of an image acquisition system for digital image correlation measurement provided in an embodiment of the present application;

[0057] Figure 2 A schematic diagram of the installation principle of an image acquisition system for digital image correlation measurement provided in an embodiment of the present application;

[0058] Figure 3 A schematic diagram of a process of an image acquisition method for digital image correlation measurement provided in an embodiment of the present application Figure 1 ;

[0059] Figure 4 A schematic diagram of a process of an image acquisition method for digital image correlation measurement provided in an embodiment of the present application Figure 2 ;

[0060] Figure 5 A schematic diagram of a process of an image acquisition method for digital image correlation measurement provided in an embodiment of the present application Figure 3 ;

[0061] Figure 6 A schematic diagram of the structure of an image acquisition device for digital image correlation measurement provided in an embodiment of the present application;

[0062] Figure 7 A schematic diagram of the structure of the electronic device hardware provided in an embodiment of the present application.

[0063] Reference numerals:

[0064] 100 - image acquisition system for digital image correlation measurement; 110 - control device; 120 - image acquisition device; 130 - motion execution device;

[0065] 200-sample;

[0066] 131-electric tripod lifting mechanism; 132-electric slewing mechanism; 133-slide rail mechanism; 134-multi-degree-of-freedom motion mechanism; 1311-central electric push rod; 1312-leg; 141-first slider; 142-second slider; 151-first laser distance measuring device; 152-second laser distance measuring device; 1341-horizontal rotating platform; 1342-bend pipe; 1343-vertical pitch platform;

[0067] 610- parameter determination module; 620- adjustment device module; 630- image display module;

[0068] 700 - electronic device; 710 - processor; 720 - memory; 730 - communication component; 740 - bus. DETAILED DESCRIPTION

[0069] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0070] In the embodiments of the present application, words such as "first" and "second" are used to distinguish the same or similar items with basically the same functions and effects. Those skilled in the art will understand that words such as "first" and "second" do not limit the quantity and execution order, and words such as "first" and "second" do not necessarily limit the difference. It should be noted that in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the present application should not be interpreted as being more preferred or more advantageous than other embodiments or design schemes. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way. In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more.

[0071] It should be noted that the “at…” in the embodiments of the present application may be the instant when a certain situation occurs, or may be a period of time after the occurrence of a certain situation, and the embodiments of the present application do not specifically limit this.

[0072] In order to clearly describe the technical solutions of the embodiments of the present application, some terms and technologies involved in the embodiments of the present application are briefly introduced below:

[0073] Digital Image Correlation (DIC) is a non-contact optical measurement technology that calculates the displacement and strain distribution on the surface of an object by comparing the images of the object before and after deformation. The basic principle of this technology is to apply a random speckle pattern to the surface of the object, and then use one or two high-resolution cameras to take images of the object before and after deformation from different angles. By analyzing the changes in the speckle pattern in these images through software algorithms, the displacement vector of each point on the surface of the object can be calculated, and then the strain field can be obtained.

[0074] Image collector: An electronic device used to capture images or video signals. It converts optical signals into electrical signals and generates image files through digital processing for storage, transmission or further processing. Image collectors are widely used in many fields.

[0075] Speckle image: Speckle image refers to small randomly distributed spots or textures formed artificially or naturally on the surface of a material or object. This pattern is usually composed of fine particles, color changes or other surface features, which look like randomly scattered spots. Speckle images play a vital role in digital image correlation (DIC) technology. In DIC measurement, the main role of speckle images is to provide sufficient contrast and spatial changes so that the image processing algorithm can accurately track the displacement of the material surface during deformation. By comparing the position changes of the speckle pattern in the image before and after deformation, the displacement of each point can be calculated, and then the strain field can be obtained.

[0076] Field of View (FOV): refers to the spatial range that can be seen by the observer's eyes or optical instruments (such as cameras, telescopes, microscopes, etc.). In short, it is the size of the viewing angle, that is, the width or angle of the area that the observer or device can see clearly.

[0077] DIC is a non-contact full-field optical measurement technology. It uses image correlation method to calculate the displacement and deformation parameters of the full-field speckle on the surface of the test object based on a series of speckle images of the sample surface taken by two image collectors. It is widely used in professional scientific and engineering fields such as material mechanics, mechanical engineering, micromorphology and strain analysis.

[0078] Image acquisition for DIC measurement is a complex process. In the prior art, a variety of methods are used for image acquisition, but all of them require operators at multiple ends to make adjustments according to instructions to obtain images.

[0079] The operator at the control end feeds back the image conditions to the operator at the device end according to the captured image conditions, and the operator at the device end adjusts the image acquisition device and the control device so that the operator at the control end can obtain the desired image.

[0080] However, there are many problems with this debugging process: first, professionals need to invest too much energy, the debugging process is time-consuming and labor-intensive, and affects work efficiency; second, this debugging method can only be implemented in ordinary test scenarios. For complex and unconventional test environments, professionals may have debugging inconveniences. In addition, frequent manual intervention reduces the automation level of the entire system and affects overall work efficiency.

[0081] Therefore, how to improve the degree of automation in debugging digital image-related image acquisition devices is an urgent problem to be solved in this application.

[0082] Based on this, the embodiments of the present application provide an image acquisition system and method for digital image correlation measurement, which can be used in the field of image processing technology and aims to solve the above technical problems of the prior art.

[0083] Figure 1 This is an application scenario framework diagram of an image acquisition system for digital image correlation measurement provided in an embodiment of the present application. The application scenario framework diagram can be used in the various application scenarios described below, and can also be used in other application scenarios not specified.

[0084] like Figure 1 As shown, the image acquisition system 100 for digital image correlation measurement includes: a control device 110 , an image acquisition device 120 , and a motion execution device 130 .

[0085] The control device 110 of the image acquisition system 100 for digital image correlation measurement obtains relevant parameters according to the requirements of the shooting frame rate and field of view at the scene, and selects the image acquisition device 120 corresponding to the requirements according to the relevant parameters.

[0086] The image acquisition device 120 of the image acquisition system 100 for digital image correlation measurement acquires a speckle image of the sample 200 , and controls the positions of various devices of the motion execution device 130 according to the image acquisition situation, so as to acquire a desired speckle image of the sample 200 .

[0087] Figure 2 A schematic diagram of the installation principle of an image acquisition system for digital image correlation measurement provided in an embodiment of the present application. The system includes: a motion execution device, an image acquisition device and a control device;

[0088] The motion execution device includes: an electric tripod lifting mechanism, an electric slewing mechanism, a slide rail mechanism and a multi-degree-of-freedom motion mechanism; the electric slewing mechanism is rotatably connected to the electric tripod lifting mechanism, the slide rail mechanism is fixedly connected to the electric slewing mechanism, and the multi-degree-of-freedom motion mechanism is slidably connected to the slide rail mechanism;

[0089] The image acquisition device is fixedly connected to the multi-degree-of-freedom motion mechanism; the multi-degree-of-freedom motion mechanism is used to drive the image acquisition device to perform horizontal rotation movement and / or vertical pitch movement; the image acquisition device is used to capture the speckle image of the sample surface and transmit the speckle image to the control device;

[0090] The control device is used to adjust the motion parameters of the motion execution device according to the speckle image.

[0091] Specifically, the motion execution device 130 includes: an electric tripod lifting mechanism 131 , an electric rotating mechanism 132 , a slide rail mechanism 133 and a multi-degree-of-freedom motion mechanism 134 .

[0092] The electric tripod lifting mechanism 131 includes a central electric push rod 1311 and a plurality of legs 1312. The legs 1312 are used to support and fix the image acquisition system for digital image correlation measurement; the central electric push rod 1311 is retractable and can realize the height adjustment of the image acquisition device 120.

[0093] The electric rotating mechanism 132 is connected to the electric tripod lifting mechanism 131 through a connecting piece, and the electric rotating mechanism 132 can realize horizontal angle adjustment of the image acquisition device 120 through rotation. The central electric push rod 1311 can drive the height adjustment of the electric rotating mechanism 132.

[0094] The slide rail mechanism 133 and the electric rotary mechanism 132 are fixed by a connecting piece, and the specific movement mode of the slide rail mechanism 133 can be a linear slide rail or a curved slide rail. The curved slide rail needs to be customized according to the shooting requirements of the sample and the actual field of view. Two sliders are installed on the slide rail mechanism 133: a first slider 141 and a second slider 142. The movement of the slide rail mechanism 133 and the first slider 141 and the second slider 142 is realized by the slide rail. A first laser ranging device 151 is installed on the front end surface of the slide rail mechanism 133, which is used to measure the distance information between the image acquisition device 120 and the sample 200. The first slider 141 is installed with a second laser ranging device 152, and the second laser ranging device 152 is used to measure the distance between the two image acquisition devices 120, so as to adjust the spacing between the two image acquisition devices 120 according to the distance.

[0095] The multi-degree-of-freedom motion mechanism 134 is fixedly connected to two sliders installed on the slide rail mechanism 133, and the horizontal movement of the slider can drive the horizontal movement of the multi-degree-of-freedom motion mechanism 134. The multi-degree-of-freedom motion mechanism 134 includes two electric fine-tuning pan-tilt platforms. The electric fine-tuning pan-tilt platforms include a horizontal rotating platform 1341, a curved pipe 1342, and a vertical pitch platform 1343. The curved pipe 1342 is used to connect the horizontal rotating platform 1341 and the vertical pitch platform 1343; the horizontal rotating platform 1341 can rotate to achieve precise adjustment of the posture of the image acquisition device 120; the vertical pitch platform 1343 can pitch forward and backward to achieve precise adjustment of the posture of the image acquisition device 120.

[0096] There are two image acquisition devices 120 , including a lens and an image acquisition device, for acquiring a speckle image of the sample 200 .

[0097] The control mechanism 110 can select the lens and the image collector of the image acquisition device 120 according to the sample parameters, and adjust the motion execution device 130 according to the image transmitted by the image acquisition device 120 to obtain the desired speckle image.

[0098] The present application provides an image acquisition system for digital image correlation measurement, wherein the motion execution device comprises: an electric tripod lifting mechanism, an electric rotary mechanism, a slide rail mechanism and a multi-degree-of-freedom motion mechanism; the electric rotary mechanism is rotatably connected to the electric tripod lifting mechanism, the slide rail mechanism is fixedly connected to the electric rotary mechanism, and the multi-degree-of-freedom motion mechanism is slidably connected to the slide rail mechanism; the image acquisition device is fixedly connected to the multi-degree-of-freedom motion mechanism; the multi-degree-of-freedom motion mechanism is used to drive the image acquisition device to perform horizontal rotation and / or vertical pitch motion; the image acquisition device is used to capture the speckle image on the surface of the sample and transmit the speckle image to the control device; the control device is used to adjust the motion parameters of the motion execution device according to the speckle image. The following technical effects are achieved: by controlling the multi-degree-of-freedom motion mechanism, the image acquisition device is adjusted according to the shooting requirements of the image acquisition device; the operation is convenient; the control device obtains the image transmitted by the image acquisition device, and adjusts the motion execution device according to the real-time image to meet the shooting requirements; the cooperation between the motion execution device, the image acquisition device and the control device is used to realize the automatic adjustment of the image acquisition process, so that the work efficiency is improved and the automation degree of the whole system is improved.

[0099] In a possible design, the number of image acquisition devices is two, and the multi-degree-of-freedom motion mechanism includes: two electric fine-tuning pan-tilt platforms;

[0100] Each electric fine-tuning pan / tilt head includes: a horizontal rotation platform, a bending pipe and a vertical tilt platform;

[0101] For any electric fine-tuning pan / tilt, the two ends of the curved pipe are perpendicular to each other, the horizontal rotating platform is slidably connected to the slide rail mechanism, the curved pipe is rotationally connected to the horizontal rotating platform, the vertical pitch platform is rotationally connected to the curved pipe, and the image acquisition device is fixedly installed on the vertical pitch platform.

[0102] Specifically, if there are two image acquisition devices 120, then the number of the multi-degree-of-freedom motion mechanisms 134 corresponding to the image acquisition devices 120 is also two electric fine-tuning platforms. The image acquisition device 120 and the corresponding electric fine-tuning platform are fixed via a connector.

[0103] The electric fine-tuning gimbal includes a horizontal rotating platform 1341, a curved tube 1342, and a vertical pitching platform 1343. The horizontal rotating platform 1341 is fixed to the curved tube 1342, and the horizontal rotating platform 1341 can rotate to achieve the horizontal posture adjustment of the image acquisition device 120. The two ends of the curved tube 1342 are perpendicular to each other, one end is installed with the horizontal rotating platform 1341, and the other end is rotatably connected to the vertical pitching platform 1343. The vertical pitching platform 1343 can perform forward and backward pitching movements, and is fixedly connected to the image acquisition device 120 to achieve the precise posture adjustment of the image acquisition device 120 in this direction.

[0104] The technical effect provided by this embodiment is: through the design of a multi-degree-of-freedom motion mechanism, the precise position and posture adjustment of the image acquisition device can be achieved.

[0105] In one possible design, the slide rail mechanism includes: a linear slide rail;

[0106] Each horizontal rotating platform comprises a sliding block slidably connected in a linear slide rail.

[0107] Specifically, the slide rail mechanism 133 is a linear slide rail, and the linear slide rail cooperates with the two sliders through a track to make the first slider 141 and the second slider 142 move on the linear slide rail.

[0108] The technical effect provided by this embodiment is that, through the movement of the slider on the linear slide rail, the rough adjustment of the horizontal position of the image acquisition device can be achieved, thereby avoiding the inconvenience of adjustment in the horizontal direction.

[0109] In one possible design, the motion execution device further includes: a first laser distance measuring device fixedly mounted on a slider;

[0110] The first laser distance measuring device is used to measure a first distance between the two sliding blocks; wherein the second distance between the two image acquisition devices is determined based on the first distance.

[0111] Specifically, the motion execution device 130 further includes a first laser distance measuring device 151 . The first laser distance measuring device 151 is installed on the side end surface of the first slider 141 , and the side end surface of the first slider 141 refers to a surface close to the second slider 142 .

[0112] The first laser distance measuring device 151 measures a first distance between the two sliders, and obtains a second distance between the two image acquisition devices 120 according to the first distance and information of the multi-degree-of-freedom motion mechanism 134, so as to adjust the spacing between the two image acquisition devices 120 according to the second distance.

[0113] The technical effect provided by this embodiment is that through two

[0114] In one possible design, the motion execution device further includes: a second laser distance measuring device fixedly mounted on the slide rail mechanism;

[0115] The second laser distance measuring device is used to measure a third distance between the slide rail mechanism and the sample; wherein the fourth distance between the system and the sample is determined based on the third distance.

[0116] Specifically, the motion execution device 130 further includes a second laser distance measuring device 152. The second laser distance measuring device 152 is installed on the front end surface of the slide rail mechanism 133, and the front end surface of the slide rail mechanism 133 refers to the front end surface facing the direction of the sample 200.

[0117] The second laser distance measuring device 152 is used to measure a third distance between the sample 200 and the slide rail mechanism 133 , and obtain a fourth distance between the sample 200 and the image acquisition device 120 according to the third distance and relevant distance information of the image acquisition device.

[0118] The technical effect provided by this embodiment is that by installing a laser ranging device on the front end face of the slide rail mechanism, errors are reduced and the observation quality is improved; and the laser ranging device can feedback position information in real time, so that the system can adjust the action immediately to avoid erroneous operation.

[0119] In one possible design, the electric tripod lifting mechanism includes: a central electric push rod and a plurality of legs;

[0120] The central electric push rod is respectively hinged with each leg, and the electric slewing mechanism is rotatably connected to the electric tripod lifting mechanism;

[0121] The central electric push rod is used to drive the electric rotary mechanism to perform vertical lifting movement.

[0122] Specifically, the electric tripod lifting mechanism 131 includes a plurality of devices, a central electric push rod 1311 and a plurality of legs 1312. The plurality of legs 1312 are evenly distributed and fixed to the central electric push rod 1311.

[0123] The central electric push rod 1311 is retractable, and can realize the up and down movement of the electric rotary mechanism 132, thereby driving the image acquisition device 120 to be adjusted in the height direction.

[0124] The technical effect provided by this embodiment is that a plurality of evenly distributed legs are used to support the mechanism, and the central electric push rod can adapt to different workspace and travel requirements, has high flexibility, and is convenient to connect with the control system to achieve remote monitoring and automated operation, thereby avoiding the complexity of manual operation.

[0125] Figure 3 A schematic diagram of a process of an image acquisition method for digital image correlation measurement provided in an embodiment of the present application Figure 1 ,like Figure 3 shown.

[0126] S301. Determine shooting parameters of the image acquisition device according to shooting requirements of the sample.

[0127] Specifically, according to the requirements of the shooting frame rate, field of view, etc. of the sample, the control device obtains this requirement, determines the shooting parameter requirements of the image acquisition device, and selects the corresponding image acquisition device and lens.

[0128] S302, photographing a speckle image on the surface of the sample by using the image acquisition device after adjusting the photographing parameters, and adjusting the motion parameters of the motion execution device according to the speckle image.

[0129] Specifically, a speckle image of the sample surface is obtained by adjusting the image acquisition device after the shooting parameters;

[0130] According to the image condition of the speckle image, the motion execution device is adjusted until the motion execution device is adjusted to a posture corresponding to the motion parameter.

[0131] S303: Displaying the speckle image after adjusting the motion parameters.

[0132] Specifically, the control device displays the speckle image adjusted to the motion parameters.

[0133] The technical effect provided by this embodiment is that the image acquisition device outputs the corresponding requirements through the control device, and the motion execution device is automatically adjusted according to the image situation transmitted by the image acquisition device, thereby avoiding the inconvenience of actual adjustment.

[0134] Figure 4 A schematic diagram of a process of an image acquisition method for digital image correlation measurement provided in an embodiment of the present application Figure 2 This embodiment is based on the above embodiment and specifically describes the steps of the image acquisition method for digital image correlation measurement. Figure 4 shown.

[0135] S401. Determine the frequency of the image display and the focal length of the lens according to the shooting frame rate requirement and field of view requirement of the sample.

[0136] The image acquisition device includes an image display and a lens.

[0137] Specifically, the shooting parameters of the image acquisition device are determined according to the shooting requirements of the sample.

[0138] S402: Determine the required distance between the system and the sample according to the size of the surface of interest of the sample, the field of view of the image display, and the focal length of the lens.

[0139] Specifically, the desired distance between the sample and the system is determined based on the size of the sample's surface of interest, the frame rate of the image collector, and the focal length of the lens to achieve the desired image display.

[0140] S403: Determine a fourth distance between the system and the sample according to the second laser distance measuring device, and adjust the fourth distance according to the required distance.

[0141] Specifically, the fourth distance between the system and the sample is obtained according to the second laser distance measuring device installed on the front end surface of the linear slide mechanism.

[0142] According to the fourth distance, the front and rear positions of the image acquisition device are adjusted until the image acquisition device reaches the required distance.

[0143] S404, photographing a speckle image on the surface of the sample by using the image acquisition device after adjusting the photographing parameters.

[0144] Specifically, the speckle image on the surface of the sample is photographed by an image acquisition device after adjusting the shooting parameters, and the image status of the speckle image on the surface of the sample is obtained.

[0145] S405 , performing several of the multiple adjustment steps according to the speckle image until the field of view completely covers the surface of interest.

[0146] The motion execution device includes an electric tripod lifting mechanism, an electric rotating mechanism, a slide rail mechanism and a multi-degree-of-freedom motion mechanism, and the speckle image is updated in real time.

[0147] Among them, multiple adjustment steps include:

[0148] A. Control the electric tripod lifting mechanism to perform vertical lifting movement;

[0149] B. Control the electric rotary mechanism to perform horizontal rotation;

[0150] C. Control the multi-degree-of-freedom motion mechanism to perform horizontal sliding motion on the slide rail mechanism;

[0151] D. Control the multi-degree-of-freedom motion mechanism to perform horizontal rotational motion;

[0152] Specifically, according to the image condition of the speckle image, the electric tripod lifting mechanism, the electric rotating mechanism and the slider of the motion execution device are adjusted to achieve the rough adjustment in the height direction and the rough adjustment in the horizontal direction of the image acquisition device. Then, the electric fine adjustment pan / tilt on the motion execution device is adjusted to achieve the fine adjustment in the height direction and the fine adjustment in the horizontal direction of the image acquisition device.

[0153] Observe the image of the speckle image and check whether the image acquisition device covers the sample's surface of interest in the height direction. If it is not completely covered, the image acquisition device is roughly adjusted in the height field of view direction by controlling the extension and retraction of the central electric push rod, and the vertical pitch platform of the electric fine-tuning pan / tilt is controlled to make fine adjustments in the height field of view direction of the image acquisition device until the speckle image completely covers the sample's surface of interest in the height field of view.

[0154] Observe the image of the speckle image to see whether the image acquisition device is close to the surface of interest of the sample. If it is not close to the surface of interest of the sample, perform a rough adjustment in the horizontal field of view of the image acquisition device by controlling the rotation of the electric rotary mechanism.

[0155] In a possible design, the number of image acquisition devices is two, the multi-degree-of-freedom motion mechanism includes two electric fine-tuning pan-tilt platforms, and the motion execution device also includes a first laser ranging device;

[0156] Determine a second distance between the two image acquisition devices according to the first laser distance measuring device;

[0157] Determining the horizontal rotation angles of the two electric fine-tuning pan / tilt heads according to the second distance and the adjusted fourth distance;

[0158] According to the respective horizontal rotation angles of the two electric fine-tuning pan-tilt heads, the two electric fine-tuning pan-tilt heads are controlled to perform horizontal rotation movement.

[0159] Specifically, the multi-degree-of-freedom motion mechanism is controlled to perform horizontal rotational motion.

[0160] Control the multi-degree-of-freedom motion mechanism to perform vertical pitch motion.

[0161] Specifically, the distance between the two sliders is determined according to the first laser distance measuring device installed on the first slider, and the distance between the two image acquisition devices is obtained according to the information of the two image acquisition devices and the electric fine-tuning pan / tilt.

[0162] According to the system after the fourth distance adjustment, the rotation angles of the two electric fine-tuning platforms are determined, and the two electric fine-tuning platforms are controlled to perform horizontal rotational movement until a single collector covers the region of interest of the sample in the horizontal direction.

[0163] The technical effect provided by this embodiment is that, through the cooperation between multiple mechanisms and control devices, the height, orientation, posture and spacing of the image collector can be remotely adjusted, which is easy to operate, convenient and fast, and ensures the operating safety of test personnel in unconventional test environments.

[0164] In order to fully explain this embodiment, a specific embodiment is introduced here:

[0165] Figure 5 A schematic diagram of a process of an image acquisition method for digital image correlation measurement provided in an embodiment of the present application Figure 3 ,like Figure 3 shown.

[0166] S501. According to the shooting frame rate, field of view and other requirements of the sample, relevant parameters are input into the control device, and an image collector with a suitable frame rate and a lens with a focal length are output.

[0167] S502, calculating the expected distance according to the focal length, size and field of view spatial range; and adjusting the system position according to the expected distance.

[0168] According to the field of view FOV, the target size of the image acquisition device and the focal length of the lens, the working distance between the image acquisition device and the sample is calculated as follows:

[0169]

[0170] in, is the spatial range of the field of view, is the focal length of the lens, is the target size of the image collector, is the working distance.

[0171] According to the working distance, adjust the system position so that the distance between the system and the sample is the working distance.

[0172] S503: Control the motion actuator to adjust the height direction according to the image situation.

[0173] S504, controlling the electric rotary mechanism to adjust the horizontal direction according to the image condition.

[0174] Observe the image of the speckle image to see whether the image acquisition device is close to the surface of interest of the sample. If it is not close to the surface of interest of the sample, perform a rough adjustment in the horizontal field of view of the image acquisition device by controlling the rotation of the electric rotary mechanism.

[0175] At this time, the spacing between the two sliders is measured by the first laser ranging device to obtain a first distance, and based on the information of the image acquisition device and the multi-degree-of-freedom motion mechanism, the second distance between the two image collectors is calculated, and based on the second distance, the rotation angle of the horizontal rotating platform is calculated.

[0176] The calculation formula is as follows

[0177]

[0178] in, is the second distance between the two image collectors, is the working distance, is the rotation angle.

[0179] According to the calculated rotation angle, the horizontal rotating platform is controlled to rotate.

[0180] S505: Control the brightness and clarity of the image acquisition device according to the image condition.

[0181] According to the image situation, observe whether the brightness and cleanliness of the image acquisition device meet the shooting requirements. If not, adjust the aperture and focus of the image acquisition device.

[0182] S506: According to the image situation, control the frame rate of the image acquisition device to perform image acquisition.

[0183] The embodiment of the present application can divide the functional modules of the electronic device or the main control device according to the above method example. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing unit. The above integrated unit can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0184] The technical effect provided by this embodiment is that the multi-scale field of view of the image collector can be flexibly and quickly adjusted according to the needs of the tested test object; through coarse adjustment and fine adjustment, the area of ​​interest and field of view captured by the two collectors are made close in size.

[0185] Figure 6 This is a schematic diagram of the structure of an image acquisition device for digital image correlation measurement provided in an embodiment of the present application. Figure 6 As shown, the image acquisition device for digital image correlation measurement includes a parameter determination module 610 , an adjustment device module 620 and an image display module 630 .

[0186] The parameter determination module 610 is used to determine the shooting parameters of the image acquisition device according to the shooting requirements of the sample;

[0187] The adjusting device module 620 is used to capture a speckle image of the sample surface by using an image acquisition device after adjusting the capturing parameters, and adjust the motion parameters of the motion execution device according to the speckle image;

[0188] The image display module 630 is used to display the speckle image after the motion parameters are adjusted.

[0189] In a possible design, the image acquisition device includes an image display and a lens, and the parameter determination module 610 includes:

[0190] A focus adjustment module is used to determine the frequency of the image display and the focal length of the lens according to the shooting frame rate requirements and field of view requirements of the sample;

[0191] An image acquisition device for digital image correlation measurement, comprising:

[0192] A distance determination module is used to determine the required distance between the system and the sample according to the size of the surface of interest of the sample, the field of view of the image display and the focal length of the lens;

[0193] The distance calculation module is used to determine a fourth distance between the system and the sample according to the second laser distance measuring device, and adjust the fourth distance according to the required distance.

[0194] In a possible design, the motion execution device includes an electric tripod lifting mechanism, an electric rotation mechanism, a slide mechanism and a multi-degree-of-freedom motion mechanism, and the speckle image is updated in real time;

[0195] The adjustment device module 620 includes:

[0196] An adjustment module, used for performing several of the plurality of adjustment steps according to the speckle image, until the field of view completely covers the surface of interest;

[0197] Adjustment modules, including:

[0198] A vertical lifting module is used to control the electric tripod lifting mechanism to perform vertical lifting movement;

[0199] The rotary module is used to control the electric rotary mechanism to perform horizontal rotary motion;

[0200] A horizontal adjustment module is used to control the multi-degree-of-freedom motion mechanism to perform horizontal sliding motion on the slide rail mechanism;

[0201] A horizontal rotation module is used to control the multi-degree-of-freedom motion mechanism to perform horizontal rotation motion;

[0202] The vertical pitch module is used to control the multi-degree-of-freedom motion mechanism to perform vertical pitch motion.

[0203] In a possible design, the number of image acquisition devices is two, the multi-degree-of-freedom motion mechanism includes two electric fine-tuning pan-tilt platforms, and the motion execution device also includes a first laser ranging device;

[0204] Horizontal rotation module, including:

[0205] A second distance module, used to determine a second distance between the two image acquisition devices according to the first laser distance measuring device;

[0206] An angle determination module, used for determining the horizontal rotation angle of each of the two electric fine-tuning pan-tilt platforms according to the second distance and the adjusted fourth distance;

[0207] The rotation control module is used to control the two electric fine-tuning pan-tilt platforms to perform horizontal rotation according to their respective horizontal rotation angles.

[0208] The present embodiment provides an image acquisition device for digital image correlation measurement, which can execute the image acquisition method for digital image correlation measurement of the above-mentioned embodiment. The implementation principle and technical effect are similar, and will not be described in detail in the present embodiment.

[0209] In the specific implementation of the aforementioned image acquisition method for digital image correlation measurement, each module can be implemented as a processor, and the processor can execute computer-executable instructions stored in the memory, so that the processor executes the aforementioned image acquisition method for digital image correlation measurement.

[0210] Figure 7 This is a schematic diagram of the structure of the electronic device hardware provided in the embodiment of the present application. Figure 7 As shown, the electronic device 700 includes: at least one processor 710 and a memory 720. The electronic device 700 also includes a communication component 730. The processor 710, the memory 720 and the communication component 730 are connected via a bus 740.

[0211] In a specific implementation process, at least one processor 710 executes the computer-executable instructions stored in the memory 720, so that the at least one processor 710 executes an image acquisition method for digital image correlation measurement as executed by the electronic device side above.

[0212] The specific implementation process of the processor 710 can be found in the above method embodiment, and its implementation principle and technical effect are similar, so this embodiment will not be repeated here.

[0213] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the invention may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0214] The memory may include a high-speed RAM memory, and may also include a non-volatile storage NVM, such as at least one disk storage.

[0215] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of this application is not limited to only one bus or one type of bus.

[0216] The above functions implemented by the electronic device and the main control device introduce the scheme provided by the embodiment of the present application. It is understandable that in order to implement the above functions, the electronic device or the main control device includes a hardware structure and / or software module corresponding to each function. In combination with the units and algorithm steps of each example described in the embodiment disclosed in the embodiment of the present application, the embodiment of the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the technical solution of the embodiment of the present application.

[0217] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the above-mentioned image acquisition method for digital image correlation measurement.

[0218] The above-mentioned readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof.

[0219] Such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Read Only Memory (PROM), Read-Only Memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general or special purpose computer.

[0220] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (Application Specific Integrated Circuits, referred to as: ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in an electronic device or a main control device.

[0221] The present application also provides a computer program product, which includes: a computer program, which is stored in a readable storage medium. At least one processor of an electronic device can read the computer program from the readable storage medium. When the computer program is executed by the processor, it is used to implement the above-mentioned image acquisition method for digital image correlation measurement.

[0222] Those skilled in the art can understand that all or part of the steps of the above method embodiments can be completed by hardware related to program instructions. The above program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above method embodiments are executed; and the above storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0223] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments, and the above embodiments are only used to illustrate the technical solution of the present application rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An image acquisition system for digital image correlation measurement, characterized in that: include: Motion execution device, image acquisition device and control device; The motion execution device comprises: an electric tripod lifting mechanism, an electric rotary mechanism, a slide rail mechanism and a multi-degree-of-freedom motion mechanism; the electric rotary mechanism is rotatably connected to the electric tripod lifting mechanism, the slide rail mechanism is fixedly connected to the electric rotary mechanism, and the multi-degree-of-freedom motion mechanism is slidably connected to the slide rail mechanism; The image acquisition device is fixedly connected to the multi-degree-of-freedom motion mechanism; the multi-degree-of-freedom motion mechanism is used to drive the image acquisition device to perform horizontal rotation motion and / or vertical pitch motion; the image acquisition device is used to capture a speckle image of the sample surface and transmit the speckle image to the control device; The control device is used to adjust the motion parameters of the motion execution device according to the speckle image.

2. The system according to claim 1, characterized in that If the number of the image acquisition devices is two, the multi-degree-of-freedom motion mechanism comprises: two electric fine-tuning pan-tilt platforms; Each of the electric fine-tuning pan / tilt platforms comprises: a horizontal rotating platform, a curved pipe and a vertical pitch platform; For any one of the electric fine-tuning pan-tilt heads, the two ends of the curved pipe are perpendicular to each other, the horizontal rotating platform is slidably connected to the slide rail mechanism, the curved pipe is rotationally connected to the horizontal rotating platform, the vertical pitch platform is rotationally connected to the curved pipe, and the image acquisition device is fixedly mounted on the vertical pitch platform.

3. The system according to claim 2, characterized in that The slide rail mechanism comprises: a linear slide rail; Each of the horizontal rotating platforms comprises a sliding block slidably connected to the linear slide rail.

4. The system according to claim 3, characterized in that The motion execution device further comprises: a first laser distance measuring device fixedly mounted on one of the slide blocks; The first laser distance measuring device is used to measure a first distance between the two sliding blocks; wherein the second distance between the two image acquisition devices is determined based on the first distance.

5. The system according to any one of claims 1 to 4, characterized in that: The motion execution device also includes: a second laser distance measuring device fixedly mounted on the slide rail mechanism; The second laser distance measuring device is used to measure a third distance between the slide rail mechanism and the sample; wherein the fourth distance between the system and the sample is determined based on the third distance.

6. The system according to claim 1, characterized in that The electric tripod lifting mechanism comprises: a central electric push rod and a plurality of legs; The central electric push rod is respectively hinged to each of the legs, and the electric slewing mechanism is rotatably connected to the electric tripod lifting mechanism; The central electric push rod is used to drive the electric rotary mechanism to perform vertical lifting movement.

7. An image acquisition method for digital image correlation measurement, characterized in that: The method is applied to a control device of an image acquisition system for digital image correlation measurement according to any one of claims 1 to 6, wherein the system further comprises a motion execution device and an image acquisition device, and the method comprises: Determining the shooting parameters of the image acquisition device according to the shooting requirements of the sample; The image acquisition device after adjusting the shooting parameters is used to capture the speckle image on the surface of the sample, and the motion parameters of the motion execution device are adjusted according to the speckle image; Displays the speckle image after adjusting the motion parameters.

8. The method according to claim 7, characterized in that The image acquisition device includes an image display and a lens, and the determining of the shooting parameters of the image acquisition device according to the shooting requirements of the sample includes: Determining the frequency of the image display and the focal length of the lens according to the shooting frame rate requirement and the field of view requirement of the sample; The motion execution device includes a second laser ranging device. After determining the shooting parameters of the image acquisition device according to the shooting requirements of the sample, the method further includes: Determining a required distance between the system and the sample according to the size of the surface of interest of the sample, the field of view of the image display, and the focal length of the lens; According to the second laser distance measuring device, a fourth distance between the system and the sample is determined, and according to the required distance, the fourth distance is adjusted.

9. The method according to claim 8, characterized in that The motion execution device includes an electric tripod lifting mechanism, an electric rotating mechanism, a slide rail mechanism and a multi-degree-of-freedom motion mechanism, and the speckle image is updated in real time; The step of adjusting the motion parameters of the motion execution device according to the speckle image includes: According to the speckle image, performing several of the plurality of adjustment steps until the field of view completely covers the surface of interest; The multiple adjustment steps include: Controlling the electric tripod lifting mechanism to perform vertical lifting movement; Controlling the electric rotary mechanism to perform horizontal rotational motion; Controlling the multi-degree-of-freedom motion mechanism to perform horizontal sliding motion on the slide rail mechanism; Controlling the multi-degree-of-freedom motion mechanism to perform horizontal rotational motion; The multi-degree-of-freedom motion mechanism is controlled to perform vertical pitch motion.

10. The method according to claim 9, characterized in that The number of the image acquisition devices is two, the multi-degree-of-freedom motion mechanism includes two electric fine-tuning pan-tilt platforms, and the motion execution device also includes a first laser distance measuring device; The controlling the multi-degree-of-freedom motion mechanism to perform horizontal rotational motion comprises: Determine a second distance between the two image acquisition devices according to the first laser distance measuring device; Determining the horizontal rotation angle of each of the two electric fine-tuning pan / tilt platforms according to the second distance and the adjusted fourth distance; According to the respective horizontal rotation angles of the two electric fine-tuning platforms, the two electric fine-tuning platforms are controlled to perform horizontal rotation movement.

Images