Method and system for measuring the line profile of a surface

Abstract

This invention provides a method and system for measuring the line profile of a curved surface, wherein the measurement method includes the following steps: (a) contacting the test surface of the object to be measured with a contouring fixture and applying a certain pressure so that the contouring fixture and the object to be measured fit together; (b) scanning the object to be measured and the contouring fixture to obtain deformation image information of the contact surface between the object to be measured and the contouring fixture; and (c) extracting the contour line of the test surface of the object to be measured based on the captured image information and calculating the line profile of the test surface.

Description

Technical Field

[0001] This invention relates to the field of machine vision measurement, and more particularly to a method and system for measuring the line profile of curved surfaces. Background Technology

[0002] In the battery pack assembly process for new energy vehicles, individual cells need to be press-stacked together in a certain quantity and arrangement order, and then welded into battery modules through series and parallel connections. Due to uneven stress or positional variations of the individual cells, some cells may be misaligned within the pressed-up battery module. This can easily affect subsequent processes and the functionality of the battery module. Therefore, it is necessary to perform line profile inspection on the stacked cells. Profile inspection describes the accuracy of the curve shape and reflects the variation of the measured actual profile relative to the ideal profile. This method is suitable for measuring line profile accuracy.

[0003] In existing technologies, commonly used methods for detecting line profile accuracy include the template method, the contour method, the projection method, and the coordinate method. Among these methods, the template method suffers from wear and tear on the template contour as the number of measurements increases, leading to reduced accuracy. Similarly, the contour method experiences wear on both the template contour and the probe as the number of measurements increases, further reducing accuracy. The projection method can only roughly determine the degree of matching between the actual and theoretical line profile accuracy, resulting in low accuracy. The coordinate method has the disadvantage that the number of measurement points directly affects the accuracy of the measurement results; as the number of measurement points increases, the measurement process slows down, and the data processing load increases, reducing calculation speed. Furthermore, the increased number of measurements accelerates the wear and tear on the measuring instruments, thus affecting detection accuracy. Summary of the Invention

[0004] A key advantage of this invention is that it provides a method and system for measuring the profile of a curved surface. The method simulates the actual battery stacking process and uses a 2D camera to scan one end of the battery in a compressed state. This allows for the acquisition of a large amount of information in a short time, resulting in high speed and high accuracy.

[0005] Another advantage of the present invention is that it provides a method and system for measuring the profile of a curved surface, wherein the measurement method is a method for calculating the profile of a curved surface under compression, so as to achieve a fast and accurate judgment of the position accuracy of the batteries after they are arranged and stacked.

[0006] Another advantage of the present invention is that it provides a method and system for measuring the profile of a curved surface, wherein the measurement method is a profile detection under a compressed state, which is beneficial to the safe, stable and efficient output function of the battery management system, improves the safety of the production process and avoids economic losses.

[0007] Another advantage of this invention is that it provides a method and system for measuring the profile of a curved surface. The method simulates the battery pressing process, observes the deformation of the triangular press, and then preliminarily judges whether the battery pressing is qualified. The simulation method is simple and easy to operate, basically reproduces the actual process, and further verifies the authenticity and feasibility of the profile extraction method.

[0008] Another advantage of the present invention is that it provides a method and system for measuring the line profile of a curved surface, wherein the measurement method utilizes machine vision technology and uses a 2D camera to scan the end face of stacked batteries along a direction perpendicular to the pressing direction, providing a highly operable and efficient method for extracting the profile.

[0009] Another advantage of the present invention is that it provides a method and system for measuring the line profile of a curved surface, wherein the measurement method is based on 2D scanning to avoid damage to the battery surface and secondary damage to the product caused by contact sampling.

[0010] Another advantage of this invention is that it provides a method and system for measuring the line profile of a curved surface. The method is a method for calculating the line profile of a curved surface under compression. By comparing it with the theoretical profile, the method detects whether the battery pressing is qualified, ensuring the parallelism, perpendicularity and stability of the battery position, and providing a certain guarantee for the stability of the battery module performance after assembly.

[0011] According to one aspect of the present invention, a method for measuring the line profile of a curved surface, which is capable of achieving the foregoing and other objectives and advantages of the present invention, includes the following steps;

[0012] (a) The test surface of the object to be tested is brought into contact with the contouring fixture, and a certain pressure is applied so that the contouring fixture and the object to be tested fit together.

[0013] (b) Scan the test object and the contouring fixture to obtain deformation image information of the contact surface between the test object and the contouring fixture; and

[0014] (c) Extract the contour line of the test surface of the test object based on the captured image information, and calculate the line profile degree of the test surface.

[0015] According to an embodiment of the present invention, in step (a), the deformation press of the contouring fixture includes a plurality of press units arranged in sequence, and a deformation interval is formed between two adjacent press units. When the test surface of the object to be tested comes into contact with the deformation press of the contouring fixture, the press unit is deformed by pressure, and the deformation interval allows the adjacent press units to deform and extend in a direction perpendicular to the force applied to the press unit.

[0016] According to one embodiment of the present invention, the cross-section of the pressing unit of the deformation press is triangular, and the deformation interval between two adjacent pressing units is inverted triangular.

[0017] According to one embodiment of the present invention, in step (b) of the measurement method, an image acquisition device is used to scan one end of the object to be tested along a direction perpendicular to the pressing direction to obtain deformation image information of the contact surface between the object to be tested and the conforming tooling.

[0018] According to one embodiment of the present invention, in step (b) of the measurement method, the position of the image acquisition device is changed and continuously scanned at one end of the object to be measured to obtain image information of multiple sub-regions of the contact surface between the object to be measured and the contour tooling.

[0019] According to one embodiment of the present invention, in step (b) of the measurement method, the image information scanned to the sub-region is stitched together into complete image information by image stitching.

[0020] According to an embodiment of the present invention, in step (c) of the measurement method, the vertices of each of the pressing units of the contouring tooling in the image are identified, and the vertices of each of the pressing units are connected into a curve to obtain the contour line of the surface to be measured of the object to be measured.

[0021] According to one embodiment of the present invention, in step (c) of the measurement method, the extracted contour line is aligned with the theoretical contour line of the object to be measured and the maximum deviation is taken to obtain the line profile of the surface to be measured of the object to be measured.

[0022] According to another aspect of this application, the present invention further provides a system for measuring the line profile of a curved surface, comprising:

[0023] The conforming fixture is used to contact the surface of the object to be tested, and the conforming fixture deforms under pressure.

[0024] An image acquisition device scans the object under test and the contouring fixture to obtain deformation image information of the contact surface between the object under test and the contouring fixture; and

[0025] The system processor extracts the contour line of the test surface of the object under test based on the image information captured by the image acquisition device, and calculates the line profile degree of the test surface.

[0026] According to one embodiment of the present invention, the deformation press of the contouring fixture includes a plurality of press units arranged in sequence, and a deformation interval is formed between two adjacent press units. When the test surface of the object to be tested comes into contact with the deformation press of the contouring fixture, the press unit is deformed by pressure, and the deformation interval allows the adjacent press units to deform and extend in a direction perpendicular to the force applied to the press unit.

[0027] According to one embodiment of the present invention, the cross-section of the pressing unit of the deformation press is triangular, and the deformation interval between two adjacent pressing units is inverted triangular.

[0028] According to one embodiment of the present invention, the image acquisition device is a 2D camera.

[0029] According to one embodiment of the present invention, the system processor includes an image processing unit, wherein the image processing unit performs stitching processing on the image information captured by the image acquisition device to obtain complete image information corresponding to the object under test.

[0030] According to an embodiment of the present invention, the system processor further includes a contour line extraction unit and a line profile calculation unit. The contour line extraction unit extracts the vertices of each of the pressing units of the contouring tooling in the image information and connects the vertices of each of the pressing units into a continuous curve, wherein the curve is the contour line of the surface to be measured of the object under test. The line profile calculation unit obtains the line profile of the surface to be measured of the object under test based on the theoretical contour line of the object under test and the actual contour line extracted by the contour extraction unit.

[0031] The further objects and advantages of the invention will become fully apparent from the following description and accompanying drawings.

[0032] These and other objects, features and advantages of the present invention will become fully apparent from the following detailed description and accompanying drawings. Attached Figure Description

[0033] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. In the drawings, unless otherwise specified, the same reference numerals are used to denote the same parts. Wherein:

[0034] Figure 1 This is a schematic diagram of a method for measuring the line profile of a curved surface according to a first preferred embodiment of the present invention.

[0035] Figure 2 This is a schematic diagram of the contouring fixture for the surface profile measurement method of the first preferred embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram simulating the method for measuring the line profile of the surface according to the first preferred embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of the contour line extraction method for measuring the line profile of the surface according to the first preferred embodiment of the present invention.

[0038] Figure 5 This is a flowchart of the method for measuring the line profile of the surface according to the first preferred embodiment of the present invention.

[0039] Figure 6 This is a schematic diagram of the system framework of a surface profile measurement system according to the first preferred embodiment of the present invention. Detailed Implementation

[0040] It should be noted that the embodiments shown in the accompanying drawings are merely examples used to specifically and vividly explain and illustrate the concept of the present invention. They are not necessarily drawn to scale in terms of size and structure, nor do they constitute a limitation on the concept of the present invention.

[0041] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the structures shown in the various accompanying drawings. They are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0042] Referring to the accompanying drawings of this invention Figures 1 to 6As shown, a method and system for measuring the line profile of a curved surface according to a first preferred embodiment of the present invention will be described in the following description, hereinafter referred to as the method for measuring the line profile of a curved surface. The method is used to measure the line profile of the curved surface of an object under test, such as simulating the actual battery stacking process. By scanning one end of a battery in a compressed state using the method and system, a large amount of information can be obtained in a short time, with high speed and accuracy. It should be noted that the method and system are used to measure the line profile of the curved surface of an object under test, which may be, but is not limited to, assembled battery packs in a compressed state. In this preferred embodiment of the present application, the object under test is a single battery cell in a compressed state during the stacking process, where the single batteries need to be stacked together in a certain number and order, and then welded into a battery module through series and parallel connections. Due to uneven force or positional changes in the single batteries, some batteries may be misaligned inside the stacked battery module, which can easily affect subsequent processes and the function of the battery module. Therefore, it is necessary to detect the line profile of the stacked batteries. Profile accuracy measurement describes the accuracy of curve shape and reflects the variation of the actual measured profile relative to the ideal profile. This method is applicable to the measurement of line profile accuracy. Line profile accuracy measurement under compressed conditions enables the safe, stable, and efficient output function of the battery management system, which is of great significance for the safety of the production process and the avoidance of economic losses.

[0043] It is understood that the type of test object to which the measurement method and measurement system are applicable is merely exemplary and not limiting. Therefore, in other alternative embodiments of this application, the test object may also be implemented as other curved surfaces. For ease of description, the test object measured in the following measurement method and measurement system simulates the compressed state of individual cells during the actual stacking of batteries.

[0044] In the measurement method described in this application, the test surface of the object to be tested is brought into contact with a contouring fixture, and the test surface of the object to be tested is used to compress the contouring fixture, causing the contouring fixture to deform under pressure. Image information of one end of the object to be tested is acquired by an image acquisition device, and the deformation of the surface of the contouring fixture relative to the test surface of the object to be tested is identified by the image information. The contour line of the test surface of the object to be tested is obtained based on the acquired image information. The data is processed and analyzed, and compared with the theoretical contour line to obtain the line profile degree.

[0045] It should be noted that in this preferred embodiment of the present application, when the object to be tested is a press-fit battery, i.e., a battery after being arranged and stacked, the battery press-fit process is simulated by the measurement method, the deformation of the triangular press is observed, and then the quality of the battery press-fit is determined. This simulation method is simple and easy to operate, basically reproduces the actual process, and further verifies the authenticity and feasibility of the contour line extraction method in this paper. The contour degree measurement system of the curved surface is based on machine vision technology. It uses a 2D camera to scan the end face of the stacked batteries along a direction perpendicular to the press-fit direction, providing a highly operable and efficient contour line extraction method. At the same time, the 2D scanning method avoids damage to the battery surface and secondary damage to the product caused by contact sampling. In short, in this preferred embodiment of the present application, the measurement system or measurement method is a method for calculating the contour degree of a curved surface under pressing conditions. By comparing with the theoretical contour line, the quality of the battery press-fit can be detected, ensuring the parallelism, perpendicularity, and stability of the battery position, and providing a certain guarantee for the stability of the battery module performance after assembly.

[0046] Accordingly, in this preferred embodiment of the present application, the surface profile measurement system includes a contouring fixture 10. When measuring the surface of an object to be measured, the surface of the object to be measured contacts the contouring fixture 10, and the surface of the object to be measured presses against the contouring fixture 10. The contouring fixture 10 includes a base 11 and a deformation pressure 12 disposed above the base 11, wherein when the surface of the object to be measured contacts the contouring fixture 10, the surface of the object to be measured deforms the deformation pressure 12 of the contouring fixture 10.

[0047] Preferably, in this preferred embodiment of the present application, the base 11 is a corrugated plate, that is, the lower end of the base 11 is provided with a concave groove, wherein the base 11 of the contouring fixture 10 is adapted to be placed above the battery, and the concave groove of the base 11 is adapted to the upper end surface of the battery. It can be understood that in another optional embodiment of the present application, the base 11 is a flat plate structure. More preferably, the contouring fixture 10 is made of a soft material, so that when the battery to be tested is placed on top of the contouring fixture 10 or the contouring fixture 10 is placed on top of the battery, the base 11 of the contouring fixture 10 and the deformation pressure fixture 12 will not cause damage to the battery to be tested.

[0048] It is worth mentioning that, in this preferred embodiment of the present application, the base 11 of the contouring fixture 10 is supported on the bottom of the deformation pressure fixture 12, wherein the deformation pressure fixture 12 is made of a soft material. Therefore, when the deformation pressure fixture 12 of the contouring fixture 10 comes into contact with the test surface of the object to be tested, the deformation pressure fixture 12 is deformed under pressure, and the deformation pressure fixture 12 of the contouring fixture 10 does not affect the object to be tested (such as a battery) when it comes into contact with the object to be tested.

[0049] Preferably, in this preferred embodiment of the present application, the deformation press 12 of the contouring fixture 10 includes a plurality of press units 121 arranged in sequence, and a deformation gap 122 is formed between two adjacent press units 121. When the test surface of the object to be tested comes into contact with the deformation press 12 of the contouring fixture 10, the press unit 121 is deformed by pressure, and the deformation gap 122 allows the adjacent press units 121 to deform and extend in a direction perpendicular to the force applied to the press unit 121, thereby avoiding the reverse pressure or force exerted by the contouring fixture 10 on the test surface of the object to be tested.

[0050] More preferably, in this preferred embodiment of the present application, the cross-section of the pressing unit 121 of the deformation press 12 is triangular, and the deformation interval 122 between two adjacent pressing units 121 is inverted triangular. For example, when the object to be tested is a battery, it will undergo a certain deformation when pressed together with the battery under external force. By observing the deformation, it can be preliminarily determined whether the battery is pressed tightly and whether the arrangement is neat. It is understood that each pressing unit 121 of the deformation press 12 includes a bottom end and a contact tip extending integrally upward from the bottom end. The contact tip of the pressing unit 121 contacts the test surface of the object to be tested. Because the contact tip of the pressing unit 121 is narrow, it is easier to deform under force. The bottom end of the pressing unit 121 is relatively wide, which can stably support and prevent excessive deformation. It should be noted that the deformation interval 122 of the deformation press 12 provides sufficient extension space when the press unit 121 is deformed under pressure, so that the press unit 121 can extend and deform along the direction perpendicular to the force direction.

[0051] like Figure 1 As shown, the contouring fixture 10 further includes a pressure plate 13, through which the required pressure is applied to the object under test. In this preferred embodiment of the present application, the pressure plate 13 has a T-shaped structure, through which uniform pressure is applied to the object under test.

[0052] Accordingly, the contouring tooling must first be designed based on the surface of the object to be tested. For example... Figure 1 and Figure 2 As shown, according to the battery module assembly process requirements, a fixed number of batteries are arranged in a certain order and stacked multiple times. The deformation press 12 of the contouring fixture 10 will be in direct contact with the battery. Due to its relatively soft material, it will undergo a certain deformation when pressed against the battery under external force. By observing the deformation, it is possible to preliminarily determine whether the pressed battery is pressed tightly and whether the arrangement is neat.

[0053] like Figure 3 As shown, a specific number of batteries are grasped and placed on the contouring fixture 10, wherein the part of the battery to be tested is in contact with the deformation pressure 12 of the contouring fixture 10, and a certain pressure is applied so that the surface to be tested is in close contact with the deformation pressure 12.

[0054] The surface profile measurement system further includes an image acquisition device 20, wherein the image acquisition device 20 captures images of the object under test and the contouring fixture 10, and captures the deformation of the contact surface between the object under test and the contouring fixture.

[0055] Preferably, in this preferred embodiment of the application, the image acquisition device 20 is a 2D camera, which scans one end of the stacked batteries (test object) along a direction perpendicular to the pressing direction, and needs to completely capture the deformation of the contact surface between the battery (test object) and the deformation press 12 of the contouring tooling 10. It is understood that, for cases involving long actual assembly lines, it is necessary to change the camera position, take multiple consecutive images, and stitch the obtained sub-regions together to obtain a complete pressing deformation image of the assembly line.

[0056] The measurement system further includes a system processor 30, wherein the system processor 30 is communicatively connected to the image acquisition device 20, the image acquisition device 20 transmits captured image information to the system processor 30, the system processor 30 extracts the contour line of the test surface of the test object based on the captured image information, and calculates the line profile degree of the test surface of the test object based on the extracted contour line.

[0057] like Figure 4 As shown, for the entire row of batteries (the test object) after being pressed, their horizontal axes should all be on the same plane. However, due to the uneven force on the batteries during the pressing process, the batteries may shift in position after pressing. Therefore, the part of the deformation press 12 of the contouring fixture 10 that contacts the battery will undergo different degrees of deformation. For batteries that have shifted in position, the curve formed by the highest point of the deformation press 12 at the corresponding position is different from the curve of the highest point of the deformation press 12 at other adjacent positions.

[0058] Therefore, in this preferred embodiment of the application, the system processor 30 extracts the highest point of each of the deformation pressure units 121 of the contour tooling 10 that are in contact with the test surface of the object under test based on the captured image data information, and connects them into a curve, which is the contour line after the battery is pressed. For the extracted contour line, the system processor 30 aligns it with the theoretical contour line to find the maximum deviation, that is, the line profile degree.

[0059] like Figure 5 As shown, a method for measuring the line profile of a curved surface according to a first preferred embodiment of this application is illustrated in the following description, wherein the measurement method includes the following steps:

[0060] (a) The test surface of the object to be tested is brought into contact with the contouring fixture 10 and a certain pressure is applied so that the contouring fixture 10 and the object to be tested fit together.

[0061] (b) Scan the test object and the contouring fixture 10 to obtain deformation image information of the contact surface between the test object and the contouring fixture 10; and

[0062] (c) Extract the contour line of the test surface of the test object based on the captured image information, and calculate the line profile degree of the test surface.

[0063] In the measurement method described in this application, the object to be tested is a stacked battery, and the battery is in a compressed state during the stacking process. Therefore, firstly, a contouring fixture and a triangular press are used to simulate the compressed state of individual cells during the actual stacking process. Then, a 2D camera is used to scan one end of the battery in the compressed state to obtain the deformation of the contact surface between the triangular press and the battery. Finally, the contour line of the measured surface is extracted from the image, the data is processed and analyzed, and compared with the theoretical contour line to obtain the line profile degree.

[0064] In step (a) of the measurement method described in this application, the deformation press 12 of the contouring fixture 10 includes a plurality of press units 121 arranged in sequence, and a deformation gap 122 is formed between two adjacent press units 121. When the test surface of the object to be tested comes into contact with the deformation press 12 of the contouring fixture 10, the press unit 121 is deformed by pressure, and the deformation gap 122 allows the adjacent press unit 121 to deform and extend in a direction perpendicular to the force applied to the press unit 121, thereby avoiding the reverse pressure or force exerted by the contouring fixture 10 on the test surface of the object to be tested.

[0065] Accordingly, in step (a) of the measurement method described in this application, the deformation pressure 12 of the contouring fixture 10 contacts the test surface of the object to be measured, and the deformation pressure 12 of the contouring fixture is deformed under pressure.

[0066] More preferably, in this preferred embodiment of the present application, the cross-section of the pressing unit 121 of the deformation press 12 is triangular, and the deformation interval 122 between two adjacent pressing units 121 is inverted triangular. For example, when the object to be tested is a battery, it will undergo a certain deformation when pressed together with the battery under external force. By observing the deformation, it can be preliminarily determined whether the battery is pressed tightly and whether the arrangement is neat. It is understood that each pressing unit 121 of the deformation press 12 includes a bottom end and a contact tip extending integrally upward from the bottom end. The contact tip of the pressing unit 121 contacts the test surface of the object to be tested. Because the contact tip of the pressing unit 121 is narrow, it is easier to deform under force. The bottom end of the pressing unit 121 is relatively wide, which can stably support and prevent excessive deformation. It should be noted that the deformation interval 122 of the deformation press 12 provides sufficient extension space when the press unit 121 is deformed under pressure, so that the press unit 121 can extend and deform along the direction perpendicular to the force direction.

[0067] In step (b) of the measurement method, an image acquisition device 20 is used to scan one end of the object to be tested along a direction perpendicular to the pressing direction to obtain deformation image information of the contact surface between the object to be tested and the contouring tooling 10.

[0068] Furthermore, in step (b) of the measurement method, the position of the image acquisition device 20 is changed, and it is continuously scanned at one end of the object to be measured to obtain image information of multiple sub-regions of the contact surface between the object to be measured and the contour tooling.

[0069] In step (b) of the measurement method, the image information of the scanned sub-region is stitched together into complete image information by image stitching.

[0070] In step (c) of the measurement method, the vertices of each of the pressing units 121 of the contouring tooling 10 in the image are identified, and the vertices of each of the pressing units 121 are connected into a curve to obtain the contour line of the surface to be measured of the object to be measured.

[0071] In step (c) of the measurement method, the extracted contour line is aligned with the theoretical contour line of the object to be measured and the maximum deviation is taken to obtain the line profile of the surface to be measured of the object to be measured.

[0072] As an example, in this preferred embodiment of the application, the object to be tested is a stacked battery.

[0073] like Figure 6 As shown, the system processor 30 of the surface profile measurement system obtains the profile line of the test surface corresponding to the test object based on the image information of the test object and the contour tooling 10 obtained by the image acquisition device 20 using machine vision, and obtains the profile line based on the profile line.

[0074] Accordingly, the system processor 30 includes an image processing unit 31, a contour line extraction unit 32, and a line contour degree calculation unit 33. The image processing unit 31 stitches together the image information captured by the image acquisition device 20 to obtain complete image information corresponding to the object under test. Specifically, the image processing unit 31 stitches together multiple sub-region image units captured by the image acquisition device 20 corresponding to the object under test into complete image information based on image stitching. The contour line extraction unit 32 extracts the vertices of each pressing unit 121 of the contouring fixture 10 in the image information and connects the vertices of each pressing unit 121 into a continuous curve, where this curve is the contour line of the surface under test of the object under test. The line contour degree calculation unit 33 obtains the line contour degree of the surface under test of the object under test based on the theoretical contour line of the object under test and the actual contour line extracted by the contour extraction unit.

[0075] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been shown and explained in the embodiments, and any modifications or variations of the embodiments of the present invention may be made without departing from the stated principles.

Claims

1. A method for measuring the line profile of a curved surface, characterized in that, The measurement method includes the following steps; (a) The test surface of the object to be tested is brought into contact with the contouring fixture, and a certain pressure is applied so that the contouring fixture and the object to be tested fit together. The deformation press of the contouring fixture includes a plurality of press units arranged in sequence, and a deformation gap is formed between two adjacent press units. When the test surface of the object to be tested comes into contact with the deformation press of the contouring fixture, the press unit is deformed by pressure, and the deformation gap allows the adjacent press units to deform and extend in a direction perpendicular to the force applied to the press unit. (b) Scanning the test object and the contouring fixture to obtain deformation image information of the contact surface between the test object and the contouring fixture; and (c) Extract the contour line of the test surface of the test object based on the captured image information, and calculate the line profile degree of the test surface.

2. The measurement method according to claim 1, wherein the cross-section of the pressure unit of the deformation pressure tool is triangular, and the deformation interval between two adjacent pressure units is inverted triangular.

3. The measurement method according to claim 1, wherein in step (b) of the measurement method, an image acquisition device is used to scan one end of the object to be tested along a direction perpendicular to the pressing direction to obtain deformation image information of the contact surface between the object to be tested and the conforming tool.

4. The measurement method according to claim 3, wherein in step (b) of the measurement method, the position of the image acquisition device is changed, and continuous scanning is performed at one end of the object to be measured to obtain image information of multiple sub-regions of the contact surface between the object to be measured and the contour tooling.

5. The measurement method according to claim 4, wherein in step (b) of the measurement method, the image information of the scanned sub-region is stitched together into complete image information by image stitching.

6. The measurement method according to claim 5, wherein in step (c) of the measurement method, the vertices of each of the pressing units of the contouring tooling in the image are identified, and the vertices of each of the pressing units are connected into a curve to obtain the contour line of the surface to be measured of the object to be measured.

7. The measurement method according to claim 6, wherein in step (c) of the measurement method, the extracted contour line is aligned with the theoretical contour line of the object to be measured and the maximum deviation is taken to obtain the line profile degree of the surface to be measured of the object to be measured.

8. A system for measuring the line profile of a curved surface, characterized in that, include: A contouring fixture is used where the surface to be tested of the object under test contacts the contouring fixture, and the contouring fixture deforms under pressure. The deformation press of the contouring fixture includes a plurality of press units arranged in sequence, and a deformation gap is formed between two adjacent press units. When the surface to be tested of the object under test contacts the deformation press of the contouring fixture, the press unit is deformed under pressure, and the deformation gap allows adjacent press units to deform and extend in a direction perpendicular to the force applied to the press unit. An image acquisition device scans the object under test and the contouring fixture to obtain deformation image information of the contact surface between the object under test and the contouring fixture; and The system processor extracts the contour line of the test surface of the object under test based on the image information captured by the image acquisition device, and calculates the line profile degree of the test surface.

9. The measurement system according to claim 8, wherein the cross-section of the pressure unit of the deformation pressure tool is triangular, and the deformation interval between two adjacent pressure units is inverted triangular.

10. The measurement system according to claim 8, wherein the image acquisition device is a 2D camera.

11. The measurement system according to claim 8, wherein the system processor includes an image processing unit, wherein the image processing unit performs stitching processing on the image information captured by the image acquisition device to obtain complete image information corresponding to the object under test.

12. The measurement system according to claim 11, wherein the system processor further comprises a contour line extraction unit and a line profile calculation unit, wherein the contour line extraction unit extracts the vertices of each of the pressing units of the contouring tooling in the image information and connects the vertices of each of the pressing units into a continuous curve, wherein the curve is the contour line of the surface to be measured of the object to be measured; the line profile calculation unit obtains the line profile of the surface to be measured of the object to be measured based on the theoretical contour line of the object to be measured and the actual contour line extracted by the contour extraction unit.

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