Digital microscopic image processing multi-dimension strain sensor

Abstract

The application provides a digital microscopic image processing multi-dimensional strain sensor, and relates to the field of micro strain measurement. The sensor is mainly composed of a first outer tube and a second outer tube. The two tubes are connected at a certain angle and are respectively internally provided with an axially movable probe. A plurality of mark points are arranged in the probe and the first outer tube. The relative position images of the marks are acquired in real time through an image acquisition module. After being analyzed through a digital image processing technology, the displacement changes of the probe in different directions can be accurately calculated. The application utilizes the visual measurement principle to convert the physical displacement into image signals, and finally realizes high-precision measurement of multi-dimensional strain. The application can simultaneously detect micro strain in multiple directions, solves the problems of complex installation, high cost and difficult data fusion caused by the need to arrange multiple single-axis sensors in the past, and has a resolution of micrometer level and characteristics of non-contact and high sensitivity.

Description

Technical Field

[0001] This utility model relates to the field of micro-strain measurement, and in particular to a digital microscopic image processing type multidimensional strain sensor. Background Technology

[0002] With aging infrastructure and increasingly stringent requirements for building structural safety, accurately measuring minute strains in multiple dimensions has become a core challenge in the field of structural health monitoring. In civil engineering, multidimensional minute strains are key parameters for assessing the stress state, safety performance, and durability of structures.

[0003] Currently, sensors commonly used for monitoring minute strain in structures mainly include resistive strain sensors, fiber Bragg grating sensors, capacitive strain sensors, and piezoelectric sensors. However, these sensors generally suffer from problems such as complex installation processes, susceptibility to environmental interference, insufficient long-term stability, poor electromagnetic interference resistance, high cost, limited measurement accuracy, and the need to deploy multiple sensors to measure strain in multiple directions. Therefore, there is an urgent need to develop a new type of multi-dimensional minute strain sensor that can simultaneously meet the requirements of easy installation, good environmental adaptability, high long-term stability, strong electromagnetic interference resistance, low cost, and high measurement accuracy. Utility Model Content

[0004] This invention provides a digital microscopic image processing type multidimensional strain sensor, which aims to solve the problems of existing sensors being complex to install, easily affected by the external environment, and difficult to achieve high-precision micro-strain measurement in multiple directions.

[0005] To achieve the above objectives, embodiments of this utility model provide a digital microscopic image processing type multidimensional strain sensor, comprising:

[0006] The first outer tube includes a first outer end and a second outer end. A first probe that moves along the axial direction of the first outer tube is inserted into the first outer end. The end of the first probe away from the first outer end is used to fix it on the workpiece to be tested. The second outer end is used to fix it on the same workpiece to be tested. A first mark is provided on the first probe.

[0007] The second outer tube includes a third outer end and a fourth outer end, wherein the fourth outer end is connected to the first outer tube and forms an angle. The third outer end is provided with a second probe that moves axially along the second outer tube. The end of the second probe away from the first outer tube is used to fix it on the same workpiece being tested. A second mark is provided on the second probe.

[0008] A third mark is also provided inside the first outer tube. The third mark is a circular mark with a preset diameter and is located near the intersection of the movement paths of the first probe and the second probe.

[0009] An image acquisition module is installed radially through the first outer tube. The image acquisition module is used to acquire and output an image containing the position information of the first mark, the second mark, and the third mark.

[0010] Preferably, the first outer end is further provided with a first inner tube, which can move along the axial direction of the first outer tube within the first outer tube, and the first probe is fixed in the first inner tube.

[0011] Preferably, a first fixing plate is further provided in the first inner tube, and the first probe is fixed on the first fixing plate and coaxial with the first inner tube;

[0012] The first outer tube is provided with at least one first support plate along the axial direction, and the first probe passes through the first support plate.

[0013] Preferably, the end of the first inner tube away from the first outer tube and the second outer tube are respectively provided with a fixing seat for fixing the first inner tube and the first outer tube to the workpiece being tested.

[0014] Preferably, the third outer end is inserted with a second inner tube, the second inner tube can move along the axial direction of the second outer tube inside the second outer tube, and the second probe is fixed in the second inner tube.

[0015] Preferably, a second fixing plate is provided in the second inner tube, and the second probe is fixed on the second fixing plate and coaxial with the second inner tube;

[0016] The second outer tube is provided with at least one second support plate along the axial direction, and the second probe passes through the second support plate;

[0017] The end of the second inner tube away from the first outer tube is provided with another fixing seat for fixing the second inner tube to the workpiece being tested.

[0018] Preferably, a limiting platform is further provided inside the first outer tube, and the third mark is located on the plane of the limiting platform;

[0019] The first probe and the second probe slide on the plane of the limiting platform.

[0020] Preferably, the image acquisition module is a digital microscope with a field of view diameter of 5 mm and a magnification of 200-1600.

[0021] Preferably, the intersection angle Satisfying 0° < ≤90°.

[0022] Preferably, the first outer tube, the first inner tube, the second outer tube, and the second inner tube are made of carbon fiber material, and the first probe and the second probe are made of rigid material.

[0023] The above-mentioned solution of this utility model has the following beneficial effects:

[0024] This application obtains relative position information with first, second, and third markers through an image acquisition module, and outputs this information for analysis by existing technologies. It can obtain high-precision displacement values ​​in different directions, and then obtain strain in different directions through the distance between the displacement values ​​and the fixed base. It can obtain micron-level strain and achieve high-precision measurement.

[0025] Meanwhile, by utilizing a dual-probe mechanical structure with a specific included angle, combined with a high-precision image acquisition module, it is possible to measure strain in multiple directions, thus solving the problems of complex installation, high cost, and difficulty in data fusion caused by the previous requirement to deploy multiple single-axis sensors.

[0026] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the appearance of this utility model;

[0028] Figure 2 This is a cross-sectional view of the present invention.

[0029] [Explanation of Labels in the Attached Image]

[0030] 10-First outer tube, 11-First outer end, 12-Second outer end, 13-First probe, 14-First mark, 15-First inner tube, 16-First fixing plate, 17-First support plate, 18-Fixing base

[0031] 20-Second outer tube, 21-Third outer end, 22-Fourth outer end, 23-Second probe, 24-Second mark, 25-Second inner tube, 26-Second fixing plate, 27-Second support plate

[0032] 30-Limiting platform, 31-Third marker,

[0033] 40 - Image acquisition module. Detailed Implementation

[0034] To make the technical problems, technical solutions and advantages of this utility model clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0035] like Figure 1 and2 As shown, where Figure 2 The cross-section is parallel to the axial direction of the first outer tube in the figure. An embodiment of this utility model provides a digital microscopic image processing type multidimensional strain sensor, including a first outer tube 10, a second outer tube 20, and an image acquisition module 40. The two ends of the first outer tube 10 are a first outer end 11 and a second outer end 12, respectively. A first probe 13 is inserted into the first outer end 11, and the first probe 13 can move axially along the axis of the first outer tube 10 within the first outer tube 10. The end of the first probe 13 away from the first outer end 11 is fixed to the workpiece under test. The second outer tube 20 is used to fix the workpiece under test. A first mark 14 is provided on the first probe 13. The workpiece under test refers to a structure that requires micro-strain measurement.

[0036] The second outer tube 20 includes a third outer end 21 and a fourth outer end 22, wherein the fourth outer end 22 is connected to the first outer tube 10, and the axes of the second outer tube 20 and the first outer tube 10 form an angle. A second probe 23 is inserted into the third outer end 21 of the second outer tube 20. The second probe 23 can move along the axial direction of the second outer tube 20 inside the second outer tube 20. The end of the second probe 23 away from the first outer tube 10 is used to fix it on the same workpiece being tested. A second mark 24 is provided on the second probe 23.

[0037] A third mark 31 is also provided inside the aforementioned first outer tube 10. The third mark 31 is a circular mark with a preset diameter and is located at the intersection of the moving paths of the first probe 13 and the second probe 23.

[0038] The aforementioned image acquisition module 40 is installed radially through the first outer tube 10 and perpendicular to the third mark 31. The image acquisition module 40 is used to acquire and output an image containing the position information of the first mark 14, the second mark 24 and the third mark 31.

[0039] In this application, when the application is fixed on the workpiece under test, and the workpiece under test undergoes a small strain, the second outer end 12 of the first outer tube 10 is fixed, while the first probe 13 and the second probe 23 can move relative to the first outer tube 10 and the second outer tube 20, thereby causing the first mark 14 on the first probe 13 and the second mark 24 on the second probe 23 to move relative to the third mark 31. The image acquisition module 40 can capture this small displacement, obtain an image containing the position information of the first, second and third marks, and output the image.

[0040] Using existing digital image vision measurement technology, a mapping relationship between pixel distances in an image and actual physical distances is established through calibration. Pixel units are converted into physical units, and by comparing different images, the true distance between the first and second markers is obtained, i.e., the true minute displacements of the first marker 14 and the second marker 24 relative to the third marker 31 are obtained, thus yielding minute strain. Specifically, after obtaining the minute displacement along the axial direction of the first outer tube 10, the distance between the fixed position of the first probe 13 and the fixed position of the first outer tube 10 needs to be obtained. Subtracting the minute displacement along the axial direction of the first outer tube 10 from the distance between the fixed positions of the first probe 13 and the first outer tube 10 yields the minute strain along the axial direction of the first outer tube 10. Similarly, after obtaining the minute displacement along the axial direction of the second outer tube 20, the distance between the fixed position of the second probe 23 and the position of the third marker 31 needs to be obtained. Subtracting the minute displacement along the axial direction of the second outer tube 20 from the distance between the fixed position of the second probe 23 and the third marker 31 yields the minute strain along the axial direction of the second outer tube 20.

[0041] This application employs an image acquisition module 40, which can acquire the position information of the first, second, and third markers with high precision, laying a solid data foundation for obtaining high-precision micro-strain data. Furthermore, the angle between the first outer tube 10 and the second outer tube 20... Unlike traditional sensors, this one can simultaneously measure minute strains in different directions, solving the problems of inconsistent sensor mounting and cumbersome data fusion. Furthermore, the image acquisition module 40 employs non-contact optical measurement for each marker, avoiding electromagnetic interference and signal drift issues common in traditional resistance, capacitance, or piezoelectric measurements.

[0042] Furthermore, in this application, a mechanical structure with dual probes is used to measure minute displacements. This mechanical structure is highly stable, which reduces the interference of environmental factors on the measurement results.

[0043] Furthermore, a first inner tube 15 is inserted into the first outer end 11 of the first outer tube 10. One end of the first inner tube 15 is located inside the first outer tube 10, and the other end is located outside the first outer tube 10. The first inner tube 15 can move within the first outer tube 10 along the axial direction of the first outer tube 10. The first probe 13 is fixed in the axial direction of the first inner tube 15.

[0044] Furthermore, in order to ensure that the first probe 13 can move axially in the first outer tube 10, a first fixing plate 16 is also provided in the first inner tube 15. In this application, the cross-sections of the first outer tube 10, the first inner tube 15 and the first fixing plate 16 are all circular and coaxial, and the first probe 13 is fixed at the center of the first fixing plate 16.

[0045] At least one first support plate 17 is also provided along the axial direction of the first outer tube 10, and the first probe 13 passes through the first support plate 17.

[0046] Due to the limiting effect of the first support plate 17, the first probe 13 cannot move radially in the first outer tube 10, but can only move axially. The first support plate 17 supports the first probe 13, preventing it from bending. Preferably, in this embodiment, two first support plates 17 are provided, with the two support plates located on the side of the first fixing plate 16 near the second outer tube 20.

[0047] The first inner tube 15, at the end furthest from the first outer tube 10, and the second outer tube 20 are respectively provided with fixing seats 18, which fix the first inner tube 15 and the second outer tube 20 to the workpiece being tested. The distance between the two fixing seats 18 along the axial direction of the first outer tube 10 is the distance between the fixing position of the first probe 13 and the fixing position of the first outer tube 10.

[0048] Similarly, the third end 21 of the second outer tube 20 is fitted with a second inner tube 25, which can move along the axial direction of the second outer tube 20 within the second outer tube 20, and the second probe 23 is fixed in the second inner tube 25.

[0049] A second fixing plate 26 is provided in the second inner tube 25, and the second probe 23 is fixed at the center of the second fixing plate 26 and is coaxial with the second inner tube 25. At least one second support plate 27 is provided in the second outer tube 20 along the axial direction, and the second probe 23 passes through the second support plate 27; another fixing seat 18 for fixing the second inner tube 25 to the workpiece being tested is provided at the end of the second inner tube 25 away from the first outer tube 10.

[0050] The assembly relationship between the second outer tube 20 and the second inner tube 25 is the same as that between the first outer tube 10 and the first inner tube 15, so it will not be elaborated further here.

[0051] To improve the accuracy of obtaining the positional relationship of the three marks, a limiting platform 30 is provided inside the first outer tube 10. The limiting platform 30 has a semi-circular cross-sectional shape perpendicular to the first outer tube 10. The radius of the semi-circle is smaller than the diameter of the first outer tube 10. The diameter of the semi-circle extends along the axial direction of the first outer tube 10 to form a plane. The third mark 31 is located on this plane, and the first probe 13 and the second probe 23 move on the plane.

[0052] Preferably, the limiting platform 30 is disposed between two adjacent first support plates 17.

[0053] The third mark 31 is a circle with a diameter of 1 mm. The length of the second probe 23 is less than the length of the first probe 13. Since this application obtains small strain through small displacement, the first probe 13 and the second probe 23 are set at intervals. The second probe 23 moves a small distance, and the first probe 13 will not hinder the movement of the second probe 23.

[0054] The aforementioned third mark 31 is located axially near the first outer end 11 of the first outer tube 10, and axially near the second inner tube 25 of the second outer tube 20.

[0055] The aforementioned first outer tube 10 is also provided with an observation window, which is located above the limiting platform 30. The data acquisition module is installed on the observation window, and the line of sight is perpendicular to the plane of the limiting platform 30 to avoid observation errors.

[0056] Preferably, the first mark 14 and the second mark 24 on the first probe 13 and the second probe 23 are arranged in a ring around the probe in the circumferential direction.

[0057] In this application, the image acquisition module 40 is a digital microscope. The digital microscope can convert the probe's position information into electronic information for output, facilitating subsequent data processing on a PC or microcontroller. The digital microscope has a field of view diameter of 5mm and a magnification of 200-1600. By adjusting the focal length of the digital microscope, clear images of the markers located within the observation area can be obtained.

[0058] In this application, the angle between the first outer tube 10 and the second outer tube 20 Satisfying 0° < ≤90°. It can be seen that when the angle between the first outer tube 10 and the second outer tube 20... When the angle is 90°, this application obtains minute strains in two perpendicular directions; when the angle between the first outer tube 10 and the second outer tube 20 is other values, this application obtains minute strains in two different directions.

[0059] Preferably, in this application, the first outer tube 10, the first inner tube 15, the second outer tube 20, and the second inner tube 25 are all made of carbon fiber material, which has strong corrosion resistance.

[0060] Preferably, the first probe 13 and the second probe 23 are made of a rigid material.

[0061] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A digital microscopic image processing type multidimensional strain sensor, characterized in that, include: The first outer tube (10) includes a first outer end (11) and a second outer end (12). The first outer end (11) is provided with a first probe (13) that moves axially along the first outer tube (10). The end of the first probe (13) away from the first outer end (11) is used to fix it on the workpiece to be tested. The second outer end (12) is used to fix it on the same workpiece to be tested. A first mark (14) is provided on the first probe (13). The second outer tube (20) includes a third outer end (21) and a fourth outer end (22), wherein the fourth outer end (22) is connected to the first outer tube (10) and forms an angle. The third outer end (21) is provided with a second probe (23) that moves axially along the second outer tube (20). The end of the second probe (23) away from the first outer tube (10) is used to fix it on the same workpiece being tested. A second mark (24) is provided on the second probe (23). The first outer tube (10) is also provided with a third mark (31), which is a circular mark with a preset diameter. The third mark (31) is located near the intersection of the moving paths of the first probe (13) and the second probe (23). The image acquisition module (40) is installed radially through the first outer tube (10). The image acquisition module (40) is used to acquire and output an image containing the position information of the first mark (14), the second mark (24) and the third mark (31).

2. The digital microscopic image processing multidimensional strain sensor according to claim 1, characterized in that: The first outer end (11) is also provided with a first inner tube (15), which can move along the axial direction of the first outer tube (10) within the first outer tube (10), and the first probe (13) is fixed in the first inner tube (15).

3. The digital microscopic image processing multidimensional strain sensor according to claim 2, characterized in that: The first inner tube (15) is also provided with a first fixing plate (16), and the first probe (13) is fixed on the first fixing plate (16) and coaxial with the first inner tube (15); The first outer tube (10) is provided with at least one first support plate (17) along the axial direction, and the first probe (13) passes through the first support plate (17).

4. The digital microscopic image processing multidimensional strain sensor according to claim 2, characterized in that: The first inner tube (15) is provided with a fixing seat (18) at the end away from the first outer tube (10) and the second outer end (12) for fixing the first inner tube (15) and the first outer tube (10) to the workpiece being tested.

5. The digital microscopic image processing multidimensional strain sensor according to claim 1, characterized in that: The third outer end (21) is fitted with a second inner tube (25), which can move along the axial direction of the second outer tube (20) within the second outer tube (20), and the second probe (23) is fixed in the second inner tube (25).

6. The digital microscopic image processing multidimensional strain sensor according to claim 5, characterized in that: A second fixing plate (26) is provided in the second inner tube (25), and the second probe (23) is fixed on the second fixing plate (26) and coaxial with the second inner tube (25); The second outer tube (20) is provided with at least one second support plate (27) along the axial direction, and the second probe (23) passes through the second support plate (27); The second inner tube (25) is provided with another fixing seat (18) at the end away from the first outer tube (10) for fixing the second inner tube (25) to the workpiece being tested.

7. The digital microscopic image processing multidimensional strain sensor according to claim 1, characterized in that: A limiting platform (30) is also provided inside the first outer tube (10), and the third mark (31) is located on the plane of the limiting platform (30); The first probe (13) and the second probe (23) slide on the plane of the limiting platform (30).

8. The digital microscopic image processing type multidimensional strain sensor according to claim 1, characterized in that: The image acquisition module (40) is a digital microscope with a field of view diameter of 5 mm and a magnification of 200-1600.

9. The digital microscopic image processing type multidimensional strain sensor according to claim 1, characterized in that: The angle Satisfying 0° < ≤90°.

10. The digital microscopic image processing type multidimensional strain sensor according to claim 1, characterized in that: The first outer tube (10), the first inner tube (15), the second outer tube (20), and the second inner tube (25) are made of carbon fiber material, and the first probe (13) and the second probe (23) are made of rigid material.

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