High-precision field measurement device and method for thermal expansion coefficient

Abstract

The invention provides a high-precision field measurement device for a thermal expansion coefficient. The high-precision field measurement device comprises a measurement frame body, an image acquisition assembly and an image processing unit, the measuring frame body comprises a box body part, at least part of the image obtaining assembly is located in the box body part, a shooting hole is formed in the face, opposite to the obtaining end of the image obtaining assembly, of the box body part, and the shooting hole is used for being arranged opposite to a piece to be measured; the image acquisition assembly acquires an image of the to-be-measured piece through the shooting hole; and the image processing unit is electrically connected with the image acquisition assembly so as to receive and process the image of the to-be-measured piece acquired by the image acquisition assembly to obtain the thermal expansion coefficient of the to-be-measured piece. The portability of the device ensures the outdoor field use of the device, is beneficial to the authenticity of obtaining the image of the to-be-measured part, and is beneficial to improving the precision of the thermal expansion coefficient measured by the field measurement device.

Description

Technical Field

[0001] The present application relates to the field of measurement technology, and in particular to a high-precision on-site measurement device and method for thermal expansion coefficient. Background Art

[0002] Existing methods for measuring thermal expansion coefficient mainly include thermomechanical analysis, laser interferometer, X-ray diffraction, etc. These methods have high measurement accuracy, but they also have certain limitations. Most of these methods require special instruments and equipment, and have high requirements for the experimental environment. They can usually only be performed in laboratories and are difficult to measure in actual application scenarios or complex field environments. Summary of the invention

[0003] In view of this, the purpose of the present application is to provide a high-precision on-site measurement device and method for thermal expansion coefficient.

[0004] Based on the above purpose, the present application provides a high-precision on-site measurement device for thermal expansion coefficient, including: a measurement frame, an image acquisition component and an image processing unit;

[0005] The measuring frame includes a box body, the image acquisition component is at least partially located in the box body, a shooting hole is provided on a side of the box body opposite to the acquisition end of the image acquisition component, the shooting hole is used to be arranged opposite to the workpiece to be measured, and the image acquisition component acquires the image of the workpiece to be measured through the shooting hole;

[0006] The image processing unit is electrically connected to the image acquisition component to receive and process the image of the object to be measured acquired by the image acquisition component to obtain the thermal expansion coefficient of the object to be measured.

[0007] Furthermore, the measuring frame further comprises a contact portion and a connecting portion connected to each other, the contact portion is used to contact the object to be measured, and the connecting portion is located between the contact portion and the box body portion to connect the contact portion and the box body portion;

[0008] The contact portion is arranged opposite to the shooting hole, and an image hole is provided thereon, the axis of the image hole coincides with the axis of the shooting hole, and the area of ​​the image hole is not less than the area of ​​the shooting hole;

[0009] A mounting groove is provided on one side of the contact portion away from the box body, the mounting groove is arranged around the image hole, and a temperature sensor connected to the image acquisition component is arranged in the mounting groove.

[0010] Furthermore, it also includes a measuring light source, which is located on a side of the box body close to the contact portion and is arranged around the shooting hole.

[0011] Further, the connecting part includes a connecting column and a light-shielding cylinder, one end of the connecting column is connected to the contact part, and the other end is connected to a side of the box body close to the contact part, one end of the light-shielding cylinder is connected to a side of the box body close to the contact part and is arranged around the measuring light source, and the other end is connected to the contact part, and the connecting column is located in the light-shielding cylinder;

[0012] When the object to be measured is an iron object, the light shielding tube and the contact portion are magnetic structures so as to be magnetically connected to the object to be measured.

[0013] Furthermore, the image acquisition component includes a high-resolution camera and an image enhancement device. The image enhancement device is located on the camera head of the high-resolution camera and is arranged close to the shooting hole. The high-resolution camera is fixedly connected to the inner side of the box body through a camera bracket.

[0014] Furthermore, a transparent protective lens adapted to the shooting hole is provided in the shooting hole.

[0015] Furthermore, a mounting hole is provided on one side of the box body away from the shooting hole, and a control end of the image acquisition component passes through the mounting hole and is located outside the box body, and the control end includes a controller and a display.

[0016] Based on the same inventive concept, the present application also provides a high-precision on-site measurement method for thermal expansion coefficient, using the high-precision on-site measurement device for thermal expansion coefficient as described above, the measurement method comprises:

[0017] Pre-processing the workpiece to be measured to obtain the pre-processed workpiece to be measured;

[0018] Placing a high-precision on-site measurement device for thermal expansion coefficient on the pre-treated workpiece to be measured, so that the pre-treated workpiece to be measured is exposed through the shooting hole on the box body;

[0019] Recording a first temperature of the environment in which the pre-processed object to be measured is located, and operating an image acquisition component in the high-precision on-site measurement device for thermal expansion coefficient to obtain a first image of the pre-processed object to be measured corresponding to the first temperature;

[0020] In response to determining that the ambient temperature of the pre-processed object to be measured is changed from a first temperature to a second temperature, operating an image acquisition component in the high-precision on-site measurement device for the coefficient of thermal expansion to obtain a second image of the pre-processed object to be measured corresponding to the second temperature;

[0021] The image processing unit analyzes the first image and the second image to obtain a strain amount of the second image compared with the first image;

[0022] The image processing unit calculates the thermal expansion coefficient of the object to be measured based on the strain amount, the first temperature, and the second temperature.

[0023] Furthermore, the preprocessing of the workpiece to be measured to obtain the preprocessed workpiece to be measured includes:

[0024] Cleaning the workpiece to be measured to obtain the cleaned workpiece to be measured;

[0025] Evenly spraying matte white primer on the cleaned workpiece to be measured, and leaving it to stand for a preset time to obtain a workpiece to be measured with white primer;

[0026] The matte black paint is evenly sprayed on the workpiece to be measured having the white primer, and after being left to stand for a preset time, a pre-treated workpiece to be measured is obtained.

[0027] Furthermore, the preprocessing of the workpiece to be measured to obtain the preprocessed workpiece to be measured includes:

[0028] Marking the piece to be measured to obtain a marked piece to be measured, wherein the marked line is of a preset size;

[0029] The scribed workpiece to be measured is cleaned to obtain a pre-treated workpiece to be measured.

[0030] From the above description, it can be seen that the high-precision field measurement device for the thermal expansion coefficient provided by the present application has a frame by setting a measurement frame, thereby improving the portability of the field measurement device and facilitating field measurement. On this basis, a box body for accommodating an image acquisition component is set on the measurement frame to provide a good image acquisition environment for the image acquisition component, thereby preventing the external environment from affecting the accuracy of the image acquired by the image acquisition component, thereby affecting the measurement accuracy of the field measurement device, and thus improving the measurement accuracy of the field measurement device. The field measurement device of the present application acquires the image of the workpiece to be measured through the image acquisition component and transmits it to the image processing unit. The image processing unit performs processing such as analysis and calculation on the received image of the workpiece to be measured, and thus can obtain the strain of the workpiece to be measured, thereby obtaining the thermal expansion coefficient. The portability of the field measurement device ensures its use in outdoor fields, and is conducive to its acquisition of the authenticity of the image of the workpiece to be measured, thereby facilitating the field measurement device to improve the accuracy of the thermal expansion coefficient measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the present application or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 This is a schematic cross-sectional structure diagram of a high-precision on-site measurement device for thermal expansion coefficient according to an embodiment of the present application;

[0033] Figure 2 This is a schematic diagram of the three-dimensional structure of a high-precision on-site measurement device for thermal expansion coefficient according to an embodiment of the present application;

[0034] Figure 3 A schematic diagram of a process flow of a high-precision on-site measurement method of thermal expansion coefficient according to an embodiment of the present application;

[0035] Figure 4 This is a schematic diagram of an image captured after the workpiece to be measured is pre-processed with speckle painting in an embodiment of the present application;

[0036] Figure 5 This is a schematic diagram of an image captured after pre-processing of marking the workpiece to be measured in an embodiment of the present application.

[0037] In the figure: 10, measuring frame; 11, box body; 111, shooting hole; 112, mounting hole; 113, camera bracket; 12, contact part; 121, image hole; 122, mounting groove; 13, connecting part; 131, connecting column; 132, light shielding tube; 20, image acquisition component; 21, acquisition end; 22, high-resolution camera; 23, image enhancement equipment; 24, control end; 30, measuring light source. DETAILED DESCRIPTION

[0038] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0039] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be the usual meanings understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0040] The thermal expansion coefficient of a material is a characteristic indicator that describes the change in size of a material when the temperature changes, and has a direct impact on the stability of the system. For example, the mismatch between the thermal expansion coefficients of the packaging material and the chip substrate material in an electronic device will lead to interface failure; turbine blades working in a high-temperature environment need to have thermal expansion characteristics that match the casing to prevent structural damage.

[0041] Existing methods for measuring thermal expansion coefficient mainly include thermomechanical analysis (TMA), laser interferometer, X-ray diffraction, etc. These methods have high measurement accuracy, but they also have certain limitations. Most of these methods require special instruments and equipment, and have high requirements for the experimental environment. They can usually only be carried out in the laboratory and are difficult to perform in actual application scenarios or complex field environments. Traditional methods such as TMA often rely on contact measurement, which places more stringent requirements on the shape and size of the sample, especially for complex geometric shapes or large structural parts. In addition, the contact method may introduce human interference or cause local measurement errors due to limited contact points.

[0042] Based on this, the present application proposes a high-precision on-site measurement device and method for the thermal expansion coefficient, so as to measure the thermal expansion coefficient of the workpiece to be measured in actual application scenarios without affecting the measurement accuracy.

[0043] The following is a detailed description of the embodiments of the present application in conjunction with the accompanying drawings. The present application provides a high-precision on-site measurement device for thermal expansion coefficient, such as Figure 1 and Figure 2 As shown, it includes: a measuring frame 10, an image acquisition component 20 and an image processing unit;

[0044] The measuring frame 10 includes a box body 11, and the image acquisition component 20 is at least partially located in the box body 11. A shooting hole 111 is provided on a side of the box body 11 opposite to the acquisition end 21 of the image acquisition component 20. The shooting hole 111 is used to be arranged opposite to the workpiece to be measured, and the image acquisition component 20 acquires the image of the workpiece to be measured through the shooting hole 111.

[0045] The image processing unit is electrically connected to the image acquisition component 20 to receive and process the image of the object to be measured acquired by the image acquisition component 20 to obtain the thermal expansion coefficient of the object to be measured.

[0046] Specifically, the measuring frame 10 is the frame of the on-site measuring device, the acquisition end 21 of the image acquisition component 20 is located in the box body 11 of the measuring frame 10, and the control end 24 of the image acquisition component 20 is located outside the box body 11 of the measuring frame 10, so that the user can control the operation of the image acquisition component 20. The connection between the control end 24 of the image acquisition component 20 and the acquisition end 21 of the image acquisition component 20 can be a wired connection or a wireless connection under the premise of ensuring the transmission effect.

[0047] The image processing unit is electrically connected to the image acquisition component 20 (it can be a wired connection or a wireless connection under the premise of ensuring the transmission effect), and the image acquired by the image acquisition component 20 is transmitted to the image processing unit for storage and image processing. The image processing unit performs analysis based on the received image to obtain the strain and thermal expansion coefficient of the image of the workpiece to be measured acquired by the image acquisition component 20 compared with the reference image.

[0048] It should be noted that the image processing unit can be a DIC image analysis system that integrates multiple exposure image stacking, noise filtering, jitter compensation and other algorithms, and the DIC image analysis system should support sub-pixel displacement measurement, be able to process high-noise images and accurately calculate surface displacement fields. The image processing unit can be set separately from the measurement frame 10, or can be connected to the measurement frame 10, and is set with the portability of the field measurement device as the first priority.

[0049] In addition, after obtaining the strain, the image processing unit needs to obtain the temperature values ​​corresponding to the reference image and the image of the object to be measured obtained by the image acquisition component 20 respectively to calculate the thermal expansion coefficient. In the absence of temperature values, the image processing unit can only calculate the strain.

[0050] Specifically, the image acquisition component 20 has real-time processing capabilities, can perform preliminary analysis and data correction while acquiring images, and provide timely feedback to the acquisition process to optimize measurement parameters, thereby helping to improve the accuracy of the image acquisition component 20 in obtaining images of the workpiece to be measured and the accuracy of the on-site measurement device.

[0051] The image acquisition component 20 also has a multiple exposure function, which can integrate the exposure number, exposure time, coverage and accuracy of multi-target acquisition images when acquiring the image of the workpiece to be measured at one time, providing sufficient basis for the subsequent image processing unit to perform image analysis, and is conducive to acquiring the accuracy of the image of the workpiece to be measured and the accuracy of the on-site measurement device.

[0052] In this embodiment, by setting the measurement frame 10, the field measurement device has a frame, which improves the portability of the field measurement device and facilitates field measurement. On this basis, a box body 11 for accommodating the image acquisition component 20 is set on the measurement frame 10 to provide a good image acquisition environment for the image acquisition component 20, thereby preventing the external environment from affecting the accuracy of the image acquired by the image acquisition component 20, thereby affecting the measurement accuracy of the field measurement device, which is conducive to improving the measurement accuracy of the field measurement device. The field measurement device of the present application acquires the image of the workpiece to be measured through the image acquisition component 20 and transmits it to the image processing unit. The image processing unit analyzes and calculates the received image of the workpiece to be measured, and can obtain the strain of the workpiece to be measured, thereby obtaining the thermal expansion coefficient. The portability of the field measurement device ensures its use in outdoor fields, and is conducive to its acquisition of the authenticity of the image of the workpiece to be measured, thereby facilitating the field measurement device to improve the accuracy of the thermal expansion coefficient measured.

[0053] In some embodiments, the measuring frame 10 further includes a contact portion 12 and a connecting portion 13 connected to each other, wherein the contact portion 12 is used to contact the object to be measured, and the connecting portion 13 is located between the contact portion 12 and the box body 11 to connect the contact portion 12 and the box body 11;

[0054] The contact portion 12 is arranged opposite to the shooting hole 111, and is provided with an image hole 121, the axis of the image hole 121 coincides with the axis of the shooting hole 111, and the area of ​​the image hole 121 is not less than the area of ​​the shooting hole 111;

[0055] A mounting groove 122 is disposed on one side of the contact portion 12 away from the box body 11 . The mounting groove 122 is disposed around the image hole 121 . A temperature sensor connected to the image acquisition component 20 is disposed in the mounting groove 122 .

[0056] Specifically, the contact portion 12 contacts the object to be measured, and can not only position the object to be measured through the image hole 121 provided thereon, making it easier for the image acquisition component 20 to acquire the object to be measured, but also support the on-site measurement device, which is beneficial to the stability of the on-site measurement device.

[0057] The connecting portion 13 not only serves to connect the contact portion 12 and the box body 11 together, but also serves to fix the distance between the image acquisition component 20 in the box body 11 and the piece to be measured, which is beneficial for the image acquisition component 20 to acquire images of the piece to be measured under different conditions while having the same distance with the piece to be measured, and is beneficial for standardization of the images of the piece to be measured obtained by the image acquisition component 20, and further, is beneficial for the image processing unit to obtain the accuracy of the strain of the piece to be measured based on the image, which is beneficial for the measurement accuracy of the on-site measurement device, and improves the practicability and generalizability of the on-site measurement device.

[0058] The side of the contact portion 12 away from the box body 11 is used for direct contact with the object to be measured, and a mounting groove 122 is arranged thereon, which is convenient for installing a temperature sensor so that the temperature sensor is in direct contact with the object to be measured to avoid temperature measurement errors, and is also beneficial to the contact stability between the contact portion 12 and the object to be measured, which is beneficial to the on-site measurement accuracy of the on-site measurement device.

[0059] It should be noted that there are multiple mounting grooves 122, which are evenly arranged around the image hole 121. Each mounting groove 122 is provided with a temperature sensor, and the temperature measured by each temperature sensor is transmitted to the image acquisition component 20, so that the image acquisition component 20 can analyze and determine the temperature of the object to be measured.

[0060] In some embodiments, the on-site measurement device further includes a measurement light source 30 . The measurement light source 30 is located on a side of the box body 11 close to the contact portion 12 and is disposed around the shooting hole 111 .

[0061] Specifically, the measuring light source 30 is located at the periphery of the shooting hole 111 and at the outside of the box body 11, and is arranged close to the contact portion 12. The measuring light source 30 serves to fill in the light for the workpiece to be measured. When the image acquisition component 20 photographs the workpiece to be measured through the shooting hole 111, the measuring light source 30 shines on the workpiece to be measured, so that the image of the workpiece to be measured obtained by the image acquisition component 20 is clearer, which is beneficial to the subsequent analysis of the image of the workpiece to be measured by the image processing unit, and further beneficial to the measurement accuracy of the on-site measurement device.

[0062] It should be noted that the light emitted by the measuring light source 30 is monochromatic, which can avoid the color of the light of the measuring light source 30 affecting the analysis result of the image processing unit, thereby facilitating the measurement accuracy of the on-site measurement device.

[0063] In some embodiments, the connecting portion 13 includes a connecting column 131 and a light shielding tube 132, one end of the connecting column 131 is connected to the contact portion 12, and the other end is connected to a side of the box body 11 close to the contact portion 12, one end of the light shielding tube 132 is connected to a side of the box body 11 close to the contact portion 12, and is arranged around the measuring light source 30, and the other end is connected to the contact portion 12, and the connecting column 131 is located in the light shielding tube 132;

[0064] When the object to be measured is an iron object, the light shielding tube 132 and the contact portion 12 are magnetic structures to be magnetically connected to the object to be measured.

[0065] Specifically, the connecting portion 13 is configured as a connecting column 131 and a light-shielding tube 132, which can not only connect, support and fix the spacing of the connecting portion 13, but also avoid that the connection area between the connecting portion 13 and the box body 11 and the contact portion 12 is too large, affecting the image hole 121 and the shooting hole 111 on the box body 11 and the contact portion 12, thereby avoiding affecting the image acquisition component 20 to acquire images, which is beneficial to ensuring the accuracy of the on-site measurement device.

[0066] In addition, the shading tube 132 can also shield the measuring light source 30 to prevent external light from affecting the irradiation of the measuring light source 30 on the object to be measured, which is beneficial for the image acquisition component 20 to obtain the uniformity of light of the image of the object to be measured, and further beneficial to the measurement accuracy of the on-site measurement device.

[0067] When the object to be measured is an iron object (such as a rail), the connecting portion and the contact portion are both configured as magnetic structures, so that the connecting portion and the contact portion both apply magnetic attraction to the object to be measured, so that the on-site measuring device is fixedly connected to the object to be measured, thereby facilitating the measurement accuracy of the on-site measuring device at the actual site.

[0068] It should be noted that, when the piece to be measured is not made of iron, the contact portion may be a plate-like structure, and the side thereof in contact with the piece to be measured is a structure adapted to the outer surface of the piece to be measured, so that the on-site measurement device is stably connected to the piece to be measured, which is beneficial to the measurement accuracy of the on-site measurement device in the actual field.

[0069] In some embodiments, the image acquisition component 20 includes a high-resolution camera 22 and an image enhancement device 23. The image enhancement device 23 is located on the camera head of the high-resolution camera 22 and is arranged close to the shooting hole 111. The high-resolution camera 22 is fixedly connected to the inner side of the box body 11 via a camera bracket 113.

[0070] Specifically, the image enhancement device 23 can be one or more of an optical filter (such as a bandpass filter), a magnifier and a microscope. The optical filter can reduce the interference of ambient light, and the magnifier and microscope can improve the resolution of tiny features.

[0071] The high-resolution camera 22 is connected to the box body 11 via the camera bracket 113 , which ensures the stability of the high-resolution camera 22 , thereby facilitating the stability and measurement accuracy of the on-site measurement device.

[0072] In addition, the high-resolution camera 22 has a high-speed image acquisition function, and its high frame rate ensures that sufficient data can be captured to provide more detailed information for subsequent analysis. The camera needs to be equipped with a depth of field effect and a high-quality lens to ensure image clarity and detail capture capabilities. The image enhancement device 23 can make up for the shortcomings of the high-resolution camera 22 and work together with the high-resolution camera 22 to take a clearer image of the workpiece to be measured, thereby achieving optimization in terms of image acquisition, which is beneficial to improving the measurement accuracy of the on-site measurement device.

[0073] Exemplarily, the image enhancement device 23 is a microscope, which is installed together with the camera head of the high-resolution camera 22. The high-resolution camera 22 photographs the object to be measured through the microscope to improve the clarity of the photographed image, which is beneficial to the measurement accuracy of the on-site measurement device.

[0074] In some embodiments, a transparent protective lens adapted to the shooting hole 111 is disposed in the shooting hole 111 .

[0075] Specifically, the transparent protective lens is arranged in the shooting hole 111, which does not affect the image acquisition component 20 from capturing the image of the workpiece to be measured through the shooting hole 111, and can also seal the image acquisition component 20 in the box body 11, thereby preventing the external environment from damaging the image acquisition component 20, thereby preventing the normal use and measurement accuracy of the on-site measurement device from being affected, which is beneficial to the measurement accuracy and service life of the on-site measurement device.

[0076] In some embodiments, a mounting hole 112 is provided on one side of the box body 11 away from the shooting hole 111 , and a control terminal 24 of the image acquisition component 20 passes through the mounting hole 112 and is located outside the box body 11 . The control terminal 24 includes a controller and a display.

[0077] Specifically, the mounting hole 112 is adapted to the periphery of the image acquisition component 20 so that the box body 11 seals part of the structure of the image acquisition component 20 to prevent the external environment and light from affecting it, thereby affecting the image and measurement accuracy of the object to be measured.

[0078] The control terminal 24 of the image acquisition component 20 passes through the installation hole 112 and is located outside the box body 11 , so that the user can operate the control terminal 24 to control the image acquisition component 20 to perform corresponding image acquisition actions.

[0079] The controller on the control end 24 is used to control the operation of the acquisition end of the image acquisition component 20 and receive the ambient temperature value sent by the temperature sensor.

[0080] It should be noted that the image processing unit is connected to the control terminal 24 of the image acquisition component 20, and the connection may be a wired connection or a wireless connection.

[0081] Exemplarily, the image acquisition component 20 includes a high-resolution camera 22 and an image enhancement device 23, the camera of the high-resolution camera 22 is the acquisition end 21, the image enhancement device 23 is installed on the camera of the high-resolution camera 22 and is arranged close to the shooting hole 111, and the end of the high-resolution camera 22 away from the acquisition end 21 is located outside the box body 11 through the installation hole 112, and is wirelessly or wiredly connected to the image processing unit.

[0082] In some embodiments, an active anti-shake device is provided on the connecting portion 13 .

[0083] Specifically, the active anti-shake device can correct the displacement error caused by shaking between the image acquisition component 20 and the object to be measured, which is beneficial to improving the clarity of the image of the object to be measured acquired by the image acquisition component 20, and further beneficial to improving the measurement accuracy of the on-site measurement device.

[0084] Based on the same inventive concept, the present application also provides a high-precision on-site measurement method for thermal expansion coefficient, using the high-precision on-site measurement device for thermal expansion coefficient as described above, such as Figure 3 As shown, the measuring method comprises:

[0085] Step S100, pre-processing the workpiece to be measured to obtain the pre-processed workpiece to be measured;

[0086] Specifically, when measuring the thermal expansion coefficient of the workpiece to be measured on site, the surface of the workpiece to be measured must be pre-processed first to avoid impurities and other objects on the surface of the workpiece to be measured. When photographing the workpiece to be measured, the impurities and other objects affect the analysis of the image processing unit, thereby affecting the strain obtained by the analysis, resulting in a decrease in the accuracy of the on-site measurement device.

[0087] Step S200, placing a high-precision on-site measurement device for thermal expansion coefficient on the pre-treated object to be measured, so that the pre-treated object to be measured is exposed through the shooting hole 111 on the box body 11;

[0088] Specifically, in order to measure the thermal expansion coefficient of the pre-treated workpiece to be measured by the on-site measuring device, the on-site measuring device needs to be placed above the pre-treated workpiece to be measured so that the image acquisition component 20 can capture the pre-treated workpiece to be measured through the shooting hole 111 to analyze its thermal expansion coefficient.

[0089] Step S300, recording a first temperature of the environment in which the pre-processed object to be measured is located, and operating the image acquisition component 20 in the high-precision on-site measurement device for thermal expansion coefficient to obtain a first image of the pre-processed object to be measured corresponding to the first temperature;

[0090] Specifically, the image acquired by the image acquisition component 20 is first sent to the image processing unit for storage and analysis. Before the image acquisition component 20 of the field measurement device acquires the first image of the pre-processed object to be measured, the first temperature of the environment in which the pre-processed object to be measured is located is first acquired by an environmental thermometer and recorded, so that the first image has a corresponding temperature label, that is, the first temperature.

[0091] Exemplarily, when obtaining the first temperature, the user inputs the first temperature into the image processing unit, and then controls the image acquisition component 20 to obtain a first image of the part to be measured. When the image processing unit receives the first image sent by the image acquisition component 20, the first image automatically has a temperature label of the first temperature, and the image processing unit sets the first image as a reference image.

[0092] Step S400, in response to determining that the ambient temperature of the pre-processed object to be measured is changed from the first temperature to the second temperature, operating the image acquisition component 20 in the high-precision on-site measurement device for thermal expansion coefficient to obtain a second image of the pre-processed object to be measured corresponding to the second temperature;

[0093] Specifically, the ambient temperature of the object to be measured is monitored, and when the ambient temperature of the object to be measured changes from the first temperature to the second temperature, the image acquisition component 20 is controlled to obtain the second image, and the second image has a corresponding temperature label, that is, the second temperature.

[0094] Exemplarily, the user inputs the second temperature into the image processing unit, and then controls the image acquisition component 20 to obtain a second image of the part to be measured. When the image processing unit receives the second image sent by the image acquisition component 20, the second image automatically has a temperature label of the second temperature, and the image processing unit sets the second image as a measurement image.

[0095] Step S500, the image processing unit analyzes the first image and the second image to obtain a strain amount of the second image compared with the first image;

[0096] Specifically, the image processing unit analyzes the first image obtained to obtain the displacement field corresponding to the first image, and then analyzes the second image obtained to obtain the displacement field corresponding to the second image. Since the first image is a reference image and the second image is a measurement image, the image processing unit calculates the strain cloud map of the second image relative to the first image based on the displacement field of the first image, and then obtains the strain amount generated by the second temperature compared to the first temperature.

[0097] In step S600 , the image processing unit calculates the thermal expansion coefficient of the object to be measured based on the strain, the first temperature and the second temperature.

[0098] Specifically, the image processing unit calculates the thermal expansion coefficient of the object to be measured based on the known strain of the second temperature compared to the first temperature and the known first temperature and the second temperature.

[0099] Exemplarily, the strain amount is 10, the first temperature is 10° C., and the second temperature is 15° C., then the thermal expansion coefficient = 10 / (15° C.-10° C.) = 2 / ° C.

[0100] In this embodiment, by using the above-mentioned high-precision on-site measurement device for the thermal expansion coefficient, the thermal expansion coefficient of the workpiece to be measured is measured on-site in an outdoor environment, which can not only ensure the measurement accuracy, but also has a simple operation process, which is beneficial to improving the practicality of on-site measurement of strain and thermal expansion coefficient, and provides an efficient and accurate solution for micro-strain monitoring of materials in engineering practice, which is beneficial to application promotion.

[0101] In some embodiments, step S100: pre-processing the workpiece to be measured to obtain the pre-processed workpiece to be measured includes:

[0102] Step S101, cleaning the workpiece to be measured to obtain the cleaned workpiece to be measured;

[0103] Specifically, the surface of the workpiece to be measured is cleaned with cleaning products such as alcohol to remove grease and other impurities on the surface of the workpiece to be measured, thereby improving the adhesion of paint on the surface of the workpiece to be measured, thereby facilitating the measurement of the thermal expansion coefficient of the workpiece to be measured.

[0104] Step S102, spraying matte white primer evenly on the cleaned workpiece to be measured, and leaving it to stand for a preset time to obtain the workpiece to be measured with white primer;

[0105] Specifically, a thin layer of matte white primer is evenly sprayed on the cleaned workpiece to be measured. After spraying, the workpiece is left to stand for a preset time to allow the matte white primer to completely adhere to the cleaned workpiece to be measured, that is, the matte white primer is dried to obtain a workpiece to be measured with a white primer.

[0106] The preset time may be 3 to 5 minutes, preferably until the matte white primer is completely dry.

[0107] Step S103, evenly spraying matte black paint on the workpiece to be measured with the white primer, and leaving it to stand for a preset time to obtain a pre-treated workpiece to be measured.

[0108] Specifically, matte black paint is evenly sprayed on the workpiece to be measured with white primer to form black-and-white contrasting speckles on the workpiece to be measured. When the workpiece to be measured generates strain, the black-and-white contrasting speckles also generate corresponding strain. By analyzing the speckles, it is more conducive to obtaining accurate strain in subsequent analysis, thereby improving the measurement accuracy of the thermal expansion coefficient.

[0109] In this embodiment, the pre-processing is to perform speckle painting on the workpiece to be measured, so that the subsequent on-site measurement device can capture the speckle image, so as to analyze the strain generated by the workpiece to be measured through the speckle. The tiny strain of the speckle can be reflected in the change of its structure and shape, so it is beneficial to the subsequent analysis of the speckle image by the image processing unit to obtain the strain of the workpiece to be measured, and further to improve the measurement accuracy of the thermal expansion coefficient.

[0110] For example, Figure 4As shown, the first image (left image) and the second image (right image) taken by the on-site measurement device after the workpiece to be measured is pre-processed with speckle spray paint. The image processing unit can analyze the strain generated by the second image relative to the first image based on the first image.

[0111] In some embodiments, step S100: pre-processing the workpiece to be measured to obtain the pre-processed workpiece to be measured includes:

[0112] Step S100-1, marking a line on the workpiece to be measured to obtain a marked workpiece to be measured, wherein the marked line has a preset size;

[0113] Specifically, a marking tool is used to mark the workpiece to be measured, the preset size of the marking is related to the marking tool, and the type of the marking tool is related to the type of the workpiece to be measured. When the rigidity of the workpiece to be measured is relatively small, the marking tool may be an ordinary blade, etc., and when the rigidity of the workpiece to be measured is relatively large, the marking tool may be a steel bar with relatively large rigidity or a laser marker, etc.

[0114] Exemplarily, when the object to be measured is a rail, a laser marker is used to mark the rail with a spacing of 1 mm, that is, the width of the marking on the object to be measured is 1 mm.

[0115] It should be noted that the scribed workpiece to be measured may have a plurality of scribed lines, and the plurality of scribed lines have the same size and specification and the same spacing.

[0116] Step S100 - 2 , cleaning the scribed workpiece to be measured to obtain a pre-treated workpiece to be measured.

[0117] Specifically, the surface of the scribed piece to be measured is cleaned and wiped to effectively remove impurities on the surface of the scribed piece to be measured, which is beneficial to the subsequent analysis of the thermal expansion coefficient of the piece to be measured.

[0118] In this embodiment, the preprocessing is to draw a line on the piece to be measured so that the subsequent on-site measurement device can photograph the line on the piece to be measured to obtain the strain of the piece to be measured by strain analysis of the line, that is, the reference object of the strain is the line, which is beneficial to the subsequent analysis of the line image by the image processing unit to obtain the strain of the piece to be measured, thereby facilitating the improvement of the measurement accuracy of the thermal expansion coefficient.

[0119] For example, Figure 5 As shown, the first image (left image) and the second image (right image) taken by the on-site measurement device after the pre-processing of marking the workpiece to be measured, the image processing unit can analyze the strain generated by the second image relative to the first image based on the first image.

[0120] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0121] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0122] In addition, when specific details (e.g., circuits) are described to describe exemplary embodiments of the present application, it is apparent to those skilled in the art that the present application embodiments can be implemented without these specific details or with variations in these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0123] Although the present application has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations of these embodiments will be apparent to those skilled in the art in light of the foregoing description.

[0124] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. A high-precision on-site measurement device for thermal expansion coefficient, characterized in that: include: Measuring frame, image acquisition component and image processing unit; The measuring frame includes a box body, the image acquisition component is at least partially located in the box body, a shooting hole is provided on a side of the box body opposite to the acquisition end of the image acquisition component, the shooting hole is used to be arranged opposite to the workpiece to be measured, and the image acquisition component acquires the image of the workpiece to be measured through the shooting hole; The image processing unit is electrically connected to the image acquisition component to receive and process the image of the object to be measured acquired by the image acquisition component to obtain the thermal expansion coefficient of the object to be measured.

2. The high-precision on-site measurement device for thermal expansion coefficient according to claim 1, characterized in that: The measuring frame also includes a contact portion and a connecting portion connected to each other, wherein the contact portion is used to contact the object to be measured, and the connecting portion is located between the contact portion and the box body portion to connect the contact portion and the box body portion; The contact portion is arranged opposite to the shooting hole, and an image hole is provided thereon, the axis of the image hole coincides with the axis of the shooting hole, and the area of ​​the image hole is not less than the area of ​​the shooting hole; A mounting groove is provided on one side of the contact portion away from the box body, the mounting groove is arranged around the image hole, and a temperature sensor connected to the image acquisition component is arranged in the mounting groove.

3. The high-precision on-site measurement device for thermal expansion coefficient according to claim 2, characterized in that: It also includes a measuring light source, which is located on one side of the box body close to the contact portion and is arranged around the shooting hole.

4. The high-precision on-site measurement device for thermal expansion coefficient according to claim 3, characterized in that: The connecting part includes a connecting column and a light-shielding cylinder, one end of the connecting column is connected to the contact part, and the other end is connected to a side of the box body close to the contact part, one end of the light-shielding cylinder is connected to a side of the box body close to the contact part and is arranged around the measuring light source, and the other end is connected to the contact part, and the connecting column is located in the light-shielding cylinder; When the object to be measured is an iron object, the light shielding tube and the contact portion are magnetic structures so as to be magnetically connected to the object to be measured.

5. The high-precision on-site measurement device for thermal expansion coefficient according to claim 1, characterized in that: The image acquisition component includes a high-resolution camera and an image enhancement device. The image enhancement device is located on the camera head of the high-resolution camera and is arranged close to the shooting hole. The high-resolution camera is fixedly connected to the inner side of the box body through a camera bracket.

6. The high-precision on-site measurement device for thermal expansion coefficient according to claim 1, characterized in that: A transparent protective lens adapted to the shooting hole is arranged in the shooting hole.

7. The high-precision on-site measurement device for thermal expansion coefficient according to claim 1, characterized in that: A mounting hole is provided on one side of the box body away from the shooting hole. The control end of the image acquisition component passes through the mounting hole and is located outside the box body. The control end includes a controller and a display.

8. A high-precision on-site measurement method for thermal expansion coefficient, characterized in that: Using the high-precision on-site measurement device for thermal expansion coefficient according to any one of claims 1 to 7, the measurement method comprises: Pre-processing the workpiece to be measured to obtain the pre-processed workpiece to be measured; Placing a high-precision on-site measurement device for thermal expansion coefficient on the pre-treated workpiece to be measured, so that the pre-treated workpiece to be measured is exposed through the shooting hole on the box body; Recording a first temperature of the environment in which the pre-processed object to be measured is located, and operating an image acquisition component in the high-precision on-site measurement device for thermal expansion coefficient to obtain a first image of the pre-processed object to be measured corresponding to the first temperature; In response to determining that the ambient temperature of the pre-processed object to be measured is changed from a first temperature to a second temperature, operating an image acquisition component in the high-precision on-site measurement device for the coefficient of thermal expansion to obtain a second image of the pre-processed object to be measured corresponding to the second temperature; The image processing unit analyzes the first image and the second image to obtain a strain amount of the second image compared with the first image; The image processing unit calculates the thermal expansion coefficient of the object to be measured based on the strain amount, the first temperature, and the second temperature.

9. The high-precision on-site measurement method of thermal expansion coefficient according to claim 8, characterized in that: The preprocessing of the workpiece to be measured to obtain the preprocessed workpiece to be measured comprises: Cleaning the workpiece to be measured to obtain the cleaned workpiece to be measured; Evenly spraying matte white primer on the cleaned workpiece to be measured, and leaving it to stand for a preset time to obtain a workpiece to be measured with white primer; The matte black paint is evenly sprayed on the workpiece to be measured having the white primer, and after being left to stand for a preset time, a pre-treated workpiece to be measured is obtained.

10. The high-precision on-site measurement method of thermal expansion coefficient according to claim 8, characterized in that: The preprocessing of the workpiece to be measured to obtain the preprocessed workpiece to be measured comprises: Marking the piece to be measured to obtain a marked piece to be measured, wherein the marked line is of a preset size; The scribed workpiece to be measured is cleaned to obtain a pre-treated workpiece to be measured.

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