Rigid body crack measurement system and method based on ray tracing principle

Abstract

The application discloses a rigid body crack measuring system and a measuring method based on a light tracing principle, and belongs to the technical field of optical precision measurement. The rigid body crack measuring system comprises a light source, a light beam reflection device, a light beam receiving device and a monitoring module. The light beam reflection device is arranged on an emergent light path of the light source, the light beam receiving device is arranged on a reflected light path of the light beam reflection device, and the monitoring module is used for monitoring the displacement of the light beam reflection device under crack stress. In an initial state, the light source and the light beam reflection device are coaxially arranged. In a measuring process, the displacement of the light beam reflection device is obtained, the crack angle and the normal direction displacement are calculated by combining the distance between the light spot and the optical axis, the light path angle and the trigonometric function, and the non-contact design is adopted in the measuring method, so that the secondary damage of the structure is avoided, and the accurate measurement and real-time monitoring of the crack direction and width are realized.

Description

Technical Field

[0001] This invention relates to the field of optical precision measurement technology, specifically to a rigid body crack measurement system and method based on the principle of ray tracing. Background Technology

[0002] Concrete and steel structures, as rigid structures in modern engineering, directly affect the safety and durability of infrastructure such as buildings, bridges, and tunnels. Cracks are a typical defect in rigid structures caused by factors such as load, vibration, impact, environmental erosion, or temperature changes. Cracks not only weaken the load-bearing capacity of the rigid structure but can also lead to secondary disasters such as leakage and steel corrosion. Therefore, accurately measuring the occurrence, location, width, and propagation trend of cracks is of great significance for assessing the health status of rigid structures and formulating maintenance strategies.

[0003] Methods for measuring cracks in rigid structures mainly include: 1) Visual inspection, which involves manually observing and recording crack characteristics. However, the measurement process is highly subjective, making it difficult to identify minute cracks. It is unsuitable for real-time crack monitoring and cannot detect new cracks in a timely manner; 2) Ultrasonic testing, which identifies internal defects based on the propagation characteristics of sound waves in a medium. However, its adaptability to complex crack structures is limited; 3) Infrared thermal imaging, which locates cracks based on temperature field differences. However, infrared imaging has low resolution and is significantly affected by ambient temperature; 4) Radar detection, which involves emitting high-frequency electromagnetic waves into the rigid structure. When the electromagnetic waves encounter cracks, they generate reflected signals, which are received by a receiver. The location and depth of the cracks are determined through signal analysis. However, this method requires a high level of expertise from the inspectors, necessitating long-term training to accurately interpret complex radar signals. Furthermore, the equipment maintenance costs are high; 5) Fiber optic sensing monitoring, which involves embedding optical fibers into the concrete during the initial stages of construction or inspection. When cracks appear in the concrete due to shrinkage, load changes, etc., the optical fibers stretch along with the concrete deformation, causing changes in the transmitted optical signals (such as wavelength and intensity). The crack development trend is tracked by real-time monitoring of the optical signal changes using demodulation equipment. This method has the advantages of high real-time performance and high detection accuracy. However, optical fibers are easily damaged by vibration, tension and other operations during concrete pouring, and fiber breakage will lead to monitoring failure. In addition, this technology has problems such as high equipment and construction costs and difficulties in later maintenance.

[0004] In addition to the conventional crack measurement methods mentioned above, with the continuous development of laser, high-speed camera technology, and digital image processing technology, new optical monitoring methods based on image science and optical principles are gradually emerging. For example, digital image correlation (DIR) uses a high-speed camera to capture images of the surface of a rigid structure. By comparing images at different times, the displacement changes of pixels are calculated to identify the generation, location, and propagation of cracks. However, this method is sensitive to ambient lighting conditions; under adverse conditions such as low light, uneven lighting, or strong light reflection, image quality may significantly decrease, thus affecting the calculation accuracy of the correlation matching algorithm. Another example is laser scanning monitoring, which uses a laser scanner to emit a laser beam onto the surface of a rigid structure, receives the reflected signals, and constructs a three-dimensional point cloud model. By comparing point cloud models from different periods, the location, width, and depth of cracks can be accurately detected. This method offers extremely high measurement accuracy and can capture minute cracks, but it suffers from high equipment costs and low scanning efficiency on complex rigid structures. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a rigid body crack measurement system and method based on the principle of ray tracing, which realizes the measurement of the displacement in the crack direction and crack normal direction of a rigid structure.

[0006] This invention is achieved through the following technical solution:

[0007] A method for measuring rigid body cracks based on the principle of ray tracing includes the following steps:

[0008] A light source and a beam receiving device are set on one side of the measurement area, and a beam reflecting device is set on the other side of the measurement area;

[0009] The displacement of the beam reflecting device is obtained. This displacement is the displacement of the beam reflecting device under crack stress, and includes the displacement of the beam reflecting device along the x-direction. and displacement along the y-direction ;

[0010] When displacement and displacement The ratio is less than the set threshold;

[0011] Based on the light spot received by the beam receiving device from the reflected light path, determine the distance d between the light spot and the optical axis of the light source;

[0012] Based on displacement and displacement Maximum displacement And by combining the distance d between the light spot and the optical axis, the angle γ between the outgoing light path and the reflected light path is determined. According to the law of reflection and trigonometric relations, half of this angle γ is taken as the angle α of the crack.

[0013] Update the displacement based on the included angle γ and trigonometric functions. and displacement The minimum displacement in the crack is used to determine the displacement EF in the crack normal direction based on the maximum displacement and the updated minimum displacement.

[0014] Preferably, the method for determining the distance d between the light spot and the optical axis is as follows:

[0015] The outgoing light path of the light source illuminates the beam reflecting device, which reflects the outgoing light path to form a reflected light path. The reflected light path forms a light spot on the beam receiving device, and the beam receiving device determines the vertical distance d between the light spot and the optical axis.

[0016] Preferably, the method for determining the angle γ between the outgoing light path and the reflected light path is as follows:

[0017]

[0018] in, D The distance from the laser beam emission point of the light source to the reflecting surface is denoted as . It is the arctangent function.

[0019] Preferably, when the displacement and displacement The ratio is greater than the set threshold;

[0020] The angle α of the crack and the displacement EF in the direction of the crack normal are determined based on the displacement of the beam reflecting device.

[0021] Preferably, the displacement EF in the crack normal direction is calculated as follows:

[0022] .

[0023] Preferably, the method for determining the crack angle α based on the displacement of the beam reflecting device is as follows:

[0024] Based on the displacement of the beam reflecting device and displacement The deflection angle β of the beam reflecting device is calculated using trigonometric functions, and the deflection angle β is used as the angle α of the crack.

[0025] .

[0026] A measurement system for measuring rigid body cracks based on the principle of ray tracing includes a light source, a beam reflecting device, a beam receiving device, and a monitoring module. The light source and beam receiving device are fixed on one side of the measurement area, and the beam reflecting device is fixed on the other side of the measurement area. In the initial state, the light source and beam reflecting device are coaxially arranged.

[0027] The monitoring module is used to monitor the displacement of the beam reflecting device under crack stress.

[0028] Preferably, the light source is a laser, the beam reflecting device is a reflecting surface, and the laser and the reflecting surface are coaxially arranged.

[0029] Preferably, the beam receiving device is an array sensor, which is arranged in the reflected light path of the light source.

[0030] Preferably, the light source and the beam receiving device are mounted on the moving device and move synchronously.

[0031] The beam reflecting device is a plurality of such devices, which are arranged sequentially along the moving direction of the moving device, and the moving step size is the same as the distance between adjacent beam reflecting devices.

[0032] Compared with the prior art, the present invention has the following beneficial technical effects:

[0033] This application provides a method for measuring rigid body cracks based on the principle of ray tracing. By setting a light source, a beam receiving device, and a beam reflecting device on both sides of the measurement area, the displacement of the beam reflecting device under crack stress is first obtained. Then, based on the relationship between the ratio of the two and a set threshold, the crack parameters are calculated in combination with the light spot position data captured by the beam receiving device. When the ratio is less than a set threshold, the distance between the light spot and the light source's optical axis is first determined. The angle γ between the emitted and reflected light paths is then calculated based on the maximum displacement. Half of the angle γ is taken as the crack angle. The minimum displacement is then updated using the angle γ and trigonometric functions. Finally, the crack normal direction displacement EF is determined based on the maximum displacement and the updated minimum displacement. This measurement method adopts a non-contact measurement design, capturing changes in the light path through ray tracing to obtain crack parameters. This avoids secondary damage to the rigid structure being measured that may be caused by traditional contact measurements, and does not interfere with the original state of the crack. It is suitable for monitoring scenarios in high-risk environments. Secondly, based on the accuracy of the displacement data, different methods are used to calculate crack parameters. This considers the measurement accuracy under different displacement states, eliminates the need for complex numerical simulations, simplifies the calculation process, and ensures measurement accuracy. It can effectively achieve accurate measurement and real-time monitoring of the crack direction and normal direction width.

[0034] This application provides a rigid body crack measurement system based on the principle of ray tracing. Leveraging the high directionality of laser beams and the sensitivity of array sensors, crack measurement is achieved through the geometric relationship between the position of the light spot and the displacement of the reflecting surface. This system can detect the displacement and direction of the crack. With a light source and beam receiving device at its core, combined with a reflecting surface and a monitoring module, the system uses the principle of ray tracing to capture changes in the reflected light path caused by crack stress in real time. This avoids the secondary structural damage or data interference problems that may occur with traditional contact measurements, making it particularly suitable for crack monitoring in high-risk environments. Furthermore, this rigid body crack measurement system has a simple structure and is easy to install, enabling real-time crack monitoring and solving problems such as the high subjectivity of traditional visual inspections and the need for embedded structures in ultrasonic testing. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of cracks in the concrete structure of the present invention;

[0037] Figure 2 This is a schematic diagram of the rigid body crack measurement system of the present invention;

[0038] Figure 3 This is a schematic diagram of the measurement principle of the rigid body crack measurement system of the present invention;

[0039] Figure 4 This is a schematic diagram showing the displacement of the reflective surface of the present invention;

[0040] Figure 5 This is a schematic diagram of the array sensor structure of the present invention;

[0041] Figure 6 This is a schematic diagram of the measurement system for measuring rigid body cracks in Example 1;

[0042] Figure 7 This is a front view of the rigid body crack measurement system of Example 1;

[0043] Figure 8 This is a top view of the rigid body crack measurement system of Example 1.

[0044] In the diagram: 1. Crack; 2. Laser; 3. Array sensor; 4. Reflecting surface; 5. Two-dimensional grating sensor; 6. Micro-photoelectric sensor; 7. Incident beam; 8. Reflected beam; 9. Laser mounting base; 10. Optical axis; 11. Laser beam exit position; 12. Sliding track; 13. Base; 14. Vibration-proof structure; 15. Mounting base; 16. Dustproof housing; 17. Measurement area. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0047] A method for measuring rigid body cracks based on the principle of ray tracing includes the following steps:

[0048] A light source and a beam receiving device are set on one side of the measurement area, and a beam reflecting device is set on the other side of the measurement area;

[0049] The displacement of the beam reflecting device is obtained. This displacement is the displacement of the beam reflecting device under crack stress, and includes the displacement of the beam reflecting device along the x-direction. and displacement along the y-direction ;

[0050] When displacement and displacement The ratio is greater than the set threshold;

[0051] The angle α of the crack and the displacement EF in the direction of the crack normal are determined based on the displacement of the beam reflecting device.

[0052] When displacement and displacement The ratio is less than the set threshold;

[0053] Based on the light spot received by the beam receiving device from the reflected light path, determine the distance d between the light spot and the optical axis 10 of the light source;

[0054] Based on displacement and displacement Maximum displacement Combined with the distance d between the light spot and the optical axis 10, the angle γ between the outgoing light path and the reflected light path is determined. According to the law of reflection and trigonometric relations, half of this angle γ is taken as the angle α of the crack.

[0055] Update the displacement based on the included angle γ and trigonometric functions. and displacement The minimum displacement in the crack is used to determine the displacement EF in the crack normal direction based on the maximum displacement and the updated minimum displacement.

[0056] This measurement method is based on the principle of ray tracing and achieves crack parameter measurement through a non-contact optical path design. First, a light source, a beam receiver, and a beam reflector are arranged on both sides of the measurement area to construct a complete optical path system. When a crack develops in the steel structure, the crack stress causes the beam reflector to displace along the x and y directions, and the amount of displacement is determined. and displacement Is the ratio less than a set threshold? If this condition is met, the light spot formed by the reflected light path is captured using a beam receiving device, and the distance d between the light spot and the light axis of the light source is determined; then, combined with the displacement... and displacement The maximum displacement was calculated using geometric relationships, specifically the angle γ between the outgoing and reflected light paths. Based on the law of reflection and trigonometric geometry, half of γ was defined as the crack angle α. Finally, the displacement was corrected using the angle γ combined with trigonometric functions. and displacement The minimum displacement in the crack is used to determine the displacement EF in the crack normal direction by combining the maximum displacement with the corrected minimum displacement, thus achieving accurate acquisition of key crack parameters.

[0057] This measurement method first employs a non-contact measurement mode, capturing crack information through changes in the optical path. This avoids secondary damage to rigid structures caused by traditional contact measurements and does not interfere with the original state of the crack, making it suitable for long-term monitoring in high-risk environments. Second, it determines the displacement amount... and displacement The ratio is calculated in different scenarios. For cases where the ratio is small, the displacement is corrected by combining the position of the light spot and the geometric relationship. This effectively avoids the impact of small displacement measurement errors on the results and improves the measurement accuracy of crack angle and normal direction displacement. In addition, the parameters are derived based on ray tracing and trigonometric relationships, eliminating the need for complex numerical simulations. This simplifies the calculation process while ensuring real-time performance, enabling rapid response to crack changes and providing efficient and reliable technical support for the health monitoring of rigid structures.

[0058] Correspondingly, based on the above-mentioned rigid body crack measurement method based on the principle of ray tracing, this application also provides a rigid body crack measurement system based on the principle of ray tracing, including a light source, a beam reflecting device, a beam receiving device, and a monitoring module.

[0059] The light source and beam receiving device are fixed on one side of the measurement area 17, and the beam reflecting device is fixed on the other side of the measurement area 17.

[0060] The beam reflecting device is set in the outgoing light path of the light source, the beam receiving device is set in the reflected light path of the beam reflecting device, and the monitoring module is used to monitor the displacement of the beam reflecting device under crack stress.

[0061] In the initial state, the light source and the beam reflecting device are set coaxially;

[0062] During the measurement process, the angle γ between the outgoing light path and the reflected light path is determined based on the position of the light spot received by the beam receiving device, and the crack parameters are determined based on the angle γ and the displacement of the beam reflecting device.

[0063] It should be noted that this rigid body crack measurement system is used to measure rigid cracks, which are cracks formed on rigid structures. The light source and beam receiving device are independent of the measurement area and do not have physical contact. The beam reflecting device is physically fixed to the measurement area.

[0064] In the initial state, i.e. at the moment the rigid body crack measurement system is installed in the measurement area 17, the crack parameters of the measurement area 17 are monitored in real time by the rigid body crack measurement system. The crack parameters include the crack angle and the displacement in the crack normal direction, where the normal direction is the width direction of the crack.

[0065] In some embodiments, the light source is a laser 2, which is used to output an incident beam 7. The incident beam 7 illuminates the beam reflecting device. The laser 2 is fixed to one side of the measurement area 17 by a laser fixing base 9. The light emission point of the laser 2 is the laser beam emission position 11.

[0066] Optionally, the beam reflecting device is a reflecting surface 4, on which the incident beam 7 irradiates and the reflecting surface 4 reflects the incident beam 7 to form a reflected beam 8; for example, the reflecting surface 4 can be a mass-negligible optical thin film reflector.

[0067] When the reflected beam 8 of the beam reflecting device is coaxial with the incident beam 7, it indicates that no crack 1 is generated in the measurement area 17, or that the original historical cracks in the measurement area 17 have not changed.

[0068] In some embodiments, the monitoring module is a two-dimensional grating sensor 5, which is disposed on the optical axis 10 of the light source and perpendicular to the incident light beam 7.

[0069] The displacement of the reflecting surface 4 is measured by a two-dimensional grating sensor 5. This displacement is the amount of displacement of the reflecting surface 4 caused by crack stress, and includes the displacement of the reflecting surface 4 along the x and y directions. and displacement In the initial state, the optical axis 10 is coaxial with the incident beam 7.

[0070] In some embodiments, the beam receiving device is an array sensor 3, on which multiple micro-photoelectric sensors 6 are arranged in an array. The array sensor 3 is used to receive the reflected beam 8 from the reflective surface 4. The reflected beam 8 illuminates the array sensor 3 to form a light spot. The array sensor 3 outputs a vertical distance d between the light spot and the laser beam emission position 11.

[0071] The measurement method of the rigid body crack measurement system based on the principle of ray tracing provided in this application will be described in detail below.

[0072] See Figure 1 The figure shows a concrete structure cube, which is a rigid body. Rigid bodies are prone to cracks 1 at certain locations due to factors such as load, stress, and fatigue. The length, width, and height of the concrete structure cube are represented by a, b, and c, respectively. Crack 1 is formed at the location where crack 1 is prone to occur in the concrete structure cube. The coordinates of the crack measurement surface are represented by x and y. AB is the median of the long side, perpendicular to the long side.

[0073] It should be noted that the rigid body crack measurement system based on the principle of ray tracing in this application is a real-time measurement system used to monitor the generation and change process of crack 1 in measurement area 17 over a long period of time. It cannot measure historical cracks in measurement area 17. For example, if there are historical cracks in measurement area 17, the rigid body crack measurement system based on the principle of ray tracing in this application cannot measure the historical cracks, but can only measure the change state of the historical cracks.

[0074] See Figure 2-5 The measurement method of the rigid body crack measurement system based on the principle of ray tracing in this application includes the following steps:

[0075] Step 1: Install laser 2 on one side of measurement area 17, and install array sensor 3 on the laser beam emission position 11 of laser 2. Install reflective surface 4 on the other side of measurement area 17, and laser 2 and reflective surface 4 are located on the optical axis 10 of laser 2.

[0076] Step 2: Obtain the displacement of the reflecting surface 4 based on the two-dimensional grating sensor 5. The displacement of the reflecting surface 4 includes the displacement of the reflecting surface 4 along the x and y directions. and displacement Determine the displacement and the displacement ratio;

[0077] When the ratio is greater than the set threshold, step 3 is executed;

[0078] When the ratio is less than the set threshold, step 4 is executed;

[0079] Step 3: When the ratio is greater than the set threshold, according to the displacement of the reflecting surface 4 and the displacement , and combining with trigonometric functions to calculate the deflection angle β of the reflecting surface 4, and taking this deflection angle β as the angle α of the crack.

[0080]

[0081] Where, is the displacement of the reflecting surface 4 along the x direction, is the displacement of the reflecting surface 4 along the y direction.

[0082] According to the displacement of the reflecting surface 4 and the displacement , determine the displacement EF in the normal direction of the crack, and the method is as follows:

[0083]

[0084] When the deflection angle β is small, the displacement will be manifested as a very small amount. Taking the deflection angle β as the angle α of the crack, the error of the angle α of the crack is relatively large; for example, according to the current typical sensor accuracy, when / <tg5°, the measured displacement or the displacement measurement may have a relatively large error, resulting in a relatively large error in the deflection angle β. Therefore, the method of step 4 needs to be adopted.

[0085] It should be noted that during the real-time monitoring process, if there is no crack 1 in the measurement area 17, or the existing historical cracks in the measurement area 17 do not change, the displacement of the reflecting surface 4 is 0.

[0086] When a crack 1 appears in the measurement area 17, or the existing historical cracks in the measurement area 17 expand, it will cause the reflecting surface 4 to displace, and then the displacement of the reflecting surface 4 is obtained through the two-dimensional grating sensor 5.

[0087] Step 4: The incident light beam 7 generated by the laser 2 is irradiated on the reflecting surface 4, and the reflected light beam 8 of the reflecting surface 4 forms a light spot on the array sensor 3, and the array sensor 3 determines the distance d between the light spot and the laser beam exit position 11.

[0088] It should be noted that when the reflective surface 4 shows a displacement, it proves that crack 1 has appeared in the measurement area 17 or the historical crack has changed. At this time, the position of the light spot of the reflected beam 8 is measured.

[0089] When the reflective surface 4 does not undergo any displacement, the incident beam 7 generated by the light source will be reflected and return to the laser beam exit position 11 along the optical axis 10, so the position of the light spot does not change.

[0090] Step 5: Determine the angle γ between the optical axis 10 and the reflected beam 8 based on the displacement and distance d of the reflecting surface 4, using the following formula:

[0091]

[0092] in, D The distance from the laser beam emission position of the light source to the reflecting surface 4 is denoted as . This is the perpendicular distance between the light spot and the optical axis 10. It is the arctangent function.

[0093] 8. Reflected beam distance and displacement A triangular geometric relationship is formed, and the angle γ between the optical axis 10 and the reflected beam 8 can be determined according to the trigonometric function. According to the law of reflection and the triangular geometric relationship, half of this angle γ is taken as the angle α of the crack.

[0094] Depend on Figure 3 It can be seen that since the distance between the laser emission position 11 and the reflecting surface 4 is relatively large, an optical lever is formed. Even if the included angle γ is very small, the included angle γ can be more easily measured by the magnification of the optical lever. According to the trigonometric relationship, 1 / 2 of the included angle γ is equal to the angle α of the crack. Therefore, the measurement of tiny cracks can be realized based on the optical lever.

[0095] Step 6: Based on the included angle γ and displacement... And calculate the displacement using trigonometric functions. Based on the measured displacement and calculated displacement Determine the displacement EF in the direction of the crack normal.

[0096] Based on the aforementioned included angle γ and displacement and displacement From the relationship, we can see that when the included angle γ is very small, This will become a very small quantity, making it impossible to accurately calculate the values ​​of angle α and displacement EF in the crack normal direction. Figure 3 and Figure 4 The geometric relationship shows that half of the included angle γ and the angle α are the same. Therefore, substituting half of the included angle γ calculated in step 5 into the displacement in step 3... and displacement The displacement is obtained from the relationship with the deflection angle β. Then, the displacement EF in the crack normal direction is calculated.

[0097] Example 1

[0098] See Figure 6-8 A rigid body crack measurement system based on the principle of ray tracing includes a moving device, a laser 2, an array sensor 3, a reflective surface 4, and a two-dimensional grating sensor 5.

[0099] The array sensor 3 is mounted on the laser 2 and is perpendicular to the optical axis 10 of the laser 2. The array sensor 3 is located at the laser beam emission position 11. The laser 2 is connected to the moving device and is located on one side of the measurement area 17. The laser 2 can be moved by the moving device.

[0100] The number of reflective surfaces 4 is N, and the N reflective surfaces 4 are set on the fixed base 15. The multiple reflective surfaces 4 are arranged sequentially along the length direction of the fixed base 15, and the arrangement direction of the N reflective surfaces 4 is parallel to the moving direction of the laser 2. The fixed base 15 is physically fixed to the rock mass of the measurement area 17.

[0101] The mobile device includes a base 13 and a sliding rail 12. The base 13 is mounted on the vibration-damping structure 14, and the sliding rail 12 is mounted on the base 13. The laser 2 is mounted on the sliding rail 12 via the laser fixing base 9. The base 13 is provided with a dustproof shell 16.

[0102] The vibration damping structure 14 is a buffer structure designed for the measurement area 17 under vibration conditions. The vibration damping structure 14 is a suspended frame added under the base 13. The suspended structure can move relatively independently, reducing the direct effect of vibration on the beam receiving device. The vibration damping structure 14 is a damper, which can consume vibration energy and make the vibration decay rapidly.

[0103] The measurement method of the rigid body crack measurement system based on the principle of ray tracing in Example 1 will be described below.

[0104] The rigid body crack measurement system in this embodiment has N reflecting surfaces 4, each reflecting surface is a measurement point, and the number of measurement points is 1-N. Each reflecting surface 4 is equipped with a two-dimensional grating sensor 5, and the number of two-dimensional grating sensors 5 is n. During the measurement process, the above measurement method needs to be performed on each measurement point.

[0105] Step 1: Starting from measurement point N=1, measure the displacement of the first reflecting surface 4 along the x and y directions detected by the first two-dimensional grating sensor 5. 1 and displacement 1. Simultaneously, obtain the vertical distance d1 between the light spot of the array sensor 3 corresponding to measurement point 1 and the laser beam emission.

[0106] The displacement along the crack normal at measurement point 1 can be obtained using the above measurement method. 1 and angle α1.

[0107] Step 2: Repeat Step 1 to measure each measurement point and obtain the displacement in the crack normal direction corresponding to each measurement point. N and angle α N .

[0108] When measuring each measurement point, the laser 2 and array sensor 3 are moved synchronously by a moving device, and the moving distance is the distance between two adjacent reflective surfaces 4.

[0109] Step 3: When multiple cracks 1 exist in the measurement area 17, the displacement of the reflecting surface 4 at each measurement point is accumulated to obtain the total length a and total width w of crack 1 in the x and y directions. The calculation method is as follows:

[0110] a=

[0111] w=

[0112] Step 4: When there is only one long crack 1 in the measurement area 17, multiple measurement values ​​are obtained in the x and y directions. and Compare the crack displacement at each measurement point. N and angle α N The maximum displacement of crack 1 can then be obtained. max and angle α max .

[0113] Step 5: Repeat steps 1-4 according to the set measurement cycle to obtain dynamic data of the crack propagation process.

[0114] This application presents a measurement method for a rigid body crack measurement system based on the principle of ray tracing. This method can measure the width and tilt angle of crack 1 at any point within the measurement area 17 along the normal direction. The method employs non-contact measurement, avoiding contact interference with crack 1 during the measurement process, making it suitable for high-risk environments. Utilizing a laser beam generated by laser 2, this method can measure millimeter-level cracks 1, improving measurement accuracy. Real-time measurement data allows analysis of crack development trends, providing a theoretical basis for crack prevention and control. Furthermore, the rigid body crack measurement system is small in size, easy to install, and the microwatt-level laser can operate continuously for several years, exhibiting high reliability and stability. This enables continuous tracking of crack development, allowing for timely detection of potential hazards in infrastructure such as bridges and tunnels. It provides an efficient and reliable solution for monitoring cracks 1 in concrete structures, possessing significant engineering value and social significance for ensuring the long-term safety and sustainable operation of engineering structures.

[0115] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for measuring rigid body cracks based on the principle of ray tracing, characterized in that, The process includes the following: A light source and a beam receiving device are set on one side of the measurement area, and a beam reflecting device is set on the other side of the measurement area; The displacement of the beam reflector is measured by the monitoring module. This displacement is the displacement of the beam reflector under crack stress, and includes the displacement of the beam reflector along the x-direction. and displacement along the y-direction ; When displacement and displacement The ratio is less than the set threshold; Based on the light spot received by the beam receiving device from the reflected light path, determine the distance d between the light spot and the optical axis (10) of the light source; Based on the displacement of the beam reflecting device Combined with the distance d between the light spot and the optical axis (10), the angle γ between the outgoing light path and the reflected light path is determined. According to the law of reflection and trigonometric relations, half of this angle γ is taken as the angle α of the crack. Based on the included angle γ and displacement And calculate the displacement using trigonometric functions. Based on the measured displacement and calculated displacement Determine the displacement EF in the direction of the crack normal.

2. The rigid body crack measurement method based on the principle of ray tracing according to claim 1, characterized in that, The method for determining the distance d between the light spot and the optical axis (10) is as follows: The outgoing light path of the light source illuminates the beam reflecting device, the beam reflecting device reflects the outgoing light path to form a reflected light path, the reflected light path forms a light spot on the beam receiving device, and the beam receiving device determines the vertical distance d between the light spot and the optical axis (10).

3. The rigid body crack measurement method based on the principle of ray tracing according to claim 2, characterized in that, The method for determining the angle γ between the outgoing light path and the reflected light path is as follows: in, D The distance from the laser beam emission point of the light source to the reflecting surface is denoted as . It is the arctangent function.

4. The rigid body crack measurement method based on the principle of ray tracing according to claim 1, characterized in that, The displacement measured by the monitoring module, when the displacement... and displacement The ratio is greater than the set threshold; The angle α of the crack and the displacement EF in the direction of the crack normal are determined based on the displacement of the beam reflecting device.

5. The rigid body crack measurement method based on the principle of ray tracing according to claim 1 or 4, characterized in that, The method for calculating the displacement EF in the crack normal direction is as follows: Among them, when the displacement and displacement The ratio is greater than a set threshold. and All values ​​represent displacement measured by the monitoring module. When displacement and displacement If the ratio is less than a set threshold, then... The measured displacement , This is the displacement amount calculated.

6. The rigid body crack measurement method based on the principle of ray tracing according to claim 5, characterized in that, The method for determining the crack angle α based on the displacement of the beam reflecting device is as follows: The displacement of the beam reflecting device measured by the monitoring module and displacement The deflection angle β of the beam reflecting device is calculated using trigonometric functions, and the deflection angle β is used as the angle α of the crack. 。

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