Large rotary equipment high-speed blade deformation measurement method based on laser synchronous triggering

Abstract

The invention discloses a large-scale rotary equipment high-speed blade deformation measurement method based on laser synchronous triggering, belongs to the technical field of engine blade measurement, and solves the problems that in the prior art, when high-speed blade deformation field vision measurement is carried out, image matching fails due to the fact that a rotating phase is difficult to lock and phase deviation occurs; and the problem of image blurring caused by motion smear when a common industrial camera shoots a high-speed rotating blade is solved. A reflective digital laser sensor emits point beam laser, a reflective sticker reflects light to trigger the sensor when the blade is in a specific phase, a high-speed camera is controlled to collect speckle images, and then a digital image correlation method is used for calculating a deformation field. According to the method, the problems of difficult phase locking, image blurring and the like in high-speed blade measurement are solved through laser synchronous triggering and in combination with the reflective stickers and speckle enhanced images, the stability and accuracy of deformation field measurement are improved, and support is provided for blade strain detection.

Description

Technical Field

[0001] The present invention relates to the field of engine blade measurement, and in particular to a method for measuring deformation of high-speed blades of large-scale rotary equipment based on laser synchronous triggering. Background Art

[0002] Aircraft engines are considered the "heart" of aircraft and a vital driving force for the development of aviation. Engines rely on blades at each stage to provide powerful thrust. During operation, blades rotate at high speeds and are subjected to complex alternating loads, which can alter blade morphology, affecting system stability and thrust performance, and even causing serious failures such as blade breakage. Accurately and efficiently measuring the strain patterns of blades during operation can help improve the thrust and safety performance of aircraft engines.

[0003] For the visual measurement of high-speed blade deformation field, the rotation phase is difficult to lock in the image acquisition process, and the phase deviation leads to matching failure. A high-speed blade deformation measurement method for large rotating equipment based on laser synchronous triggering is proposed to improve the stability of blade deformation detection. Summary of the Invention

[0004] The present invention proposes a method for measuring the deformation of high-speed blades of large-scale rotating equipment based on laser synchronous triggering. By adopting a high-speed camera and a reflective digital laser sensor as a trigger device, the reflective sticker on the blade is used to make the sensor output a trigger signal when the blade rotates to a specific phase, and the high-speed camera is controlled to collect the blade image at this phase, and the camera shooting cycle is ensured to be consistent with the blade rotation cycle. At the same time, speckle is artificially sprayed on the blade surface to enhance the image features. This solves the problems in the existing technology of visual measurement of high-speed blade deformation fields, such as the difficulty in locking the rotation phase and the failure of image matching due to phase deviation, and the motion smear and blurred image when ordinary industrial cameras are used to shoot high-speed rotating blades.

[0005] A method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering includes the following steps: S1, emits a spot laser beam to the high-speed rotating blade through a reflective digital laser sensor; S2. When the blade rotates to a specific phase, the spot laser beam irradiates the reflective sticker on the blade surface. The reflected light intensity exceeds the set threshold, triggering the sensor to output a level signal. S3, using the level signal as an external trigger signal to control the high-speed camera to collect the speckle area image on the blade surface at the specific phase; S4. Based on the speckle area image, the blade deformation field is calculated by digital image correlation method.

[0006] Furthermore, the reflective digital laser sensor includes a laser probe and a signal amplifier. The laser beam width is controlled to a spot beam width by adjusting the exit port of the laser probe, and the reflected light intensity threshold is set by the amplifier to generate a trigger level signal.

[0007] Furthermore, the reflective sticker is attached to a blade adjacent to the blade being measured.

[0008] Furthermore, before executing S1, speckles are artificially sprayed on the surface of the blade, and the speckle area is used for grayscale feature matching in the digital image correlation method.

[0009] Furthermore, in S3, the exposure time of the high-speed camera is shorter than the blade rotation period; the acquisition process needs to be combined with high-brightness light source illumination.

[0010] Furthermore, in S3, the shooting cycle of the high-speed camera is synchronized with the rotation cycle of the blade, so that each frame of the collected image corresponds to the same phase of the blade rotation.

[0011] Furthermore, in S3, when the blade is in a non-specific phase, the high-speed camera does not trigger acquisition, and only the continuous image sequence of the same phase is retained for deformation analysis.

[0012] Furthermore, in S4, when matching the acquired images, the strain field is calculated and the background noise is filtered by comparing the grayscale distribution difference of the speckle area of ​​the same phase image before and after deformation.

[0013] A storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering.

[0014] A computer device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement the above-mentioned method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering.

[0015] Beneficial effects of the present invention: The present invention provides a high-speed blade deformation measurement method for large-scale rotating equipment based on laser synchronous triggering. It aims to solve the problems existing in the visual measurement of the deformation field of high-speed rotating blades, such as the difficulty in locking the rotation phase, the failure of image matching caused by phase deviation, and image blur caused by motion smear when shooting with ordinary industrial cameras. By adopting a laser synchronous triggering scheme, that is, using a reflective digital laser sensor in combination with a high-speed camera, combined with the reflective sticker on the blade, it can realize the precise acquisition of the blade image of a specific phase, and at the same time enhance the image features with the help of artificial spraying speckle, effectively improve the stability and accuracy of the blade deformation field measurement, ensure the reliability of the image matching of the detection point, and provide strong support for the accurate and efficient detection of the strain law of the blade during operation. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 It is a schematic diagram of the measuring and triggering device; Figure 2 Schematic diagram of image acquisition effects at different times; Figure 3 Schematic diagram of image matching effects at different times. DETAILED DESCRIPTION

[0016] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0017] Reference Figure 1-Figure 3 As shown, a method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering includes the following steps: S1, emits a spot laser beam to the high-speed rotating blade through a reflective digital laser sensor; S2. When the blade rotates to a specific phase, the spot laser beam irradiates the reflective sticker on the blade surface. The reflected light intensity exceeds the set threshold, triggering the sensor to output a level signal. S3, using the level signal as an external trigger signal to control the high-speed camera to collect the speckle area image on the blade surface at the specific phase; S4. Based on the speckle area image, the blade deformation field is calculated by digital image correlation method.

[0018] Specifically, the present invention effectively solves the problem of visual measurement of high-speed blade deformation field in the prior art by adopting a laser synchronous triggering scheme that combines a high-speed camera with a reflective digital laser sensor. By utilizing the reflective sticker on the blade, the sensor can output a trigger signal when the blade rotates to a specific phase, accurately controlling the high-speed camera to collect the blade image at that phase, and ensuring that the camera shooting cycle is consistent with the blade rotation cycle, which greatly improves the accuracy of blade rotation phase locking and effectively avoids the problem of image matching failure caused by phase deviation. At the same time, the use of a high-speed camera with a short exposure time and the artificial spraying of speckles on the blade surface not only overcome the disadvantage of motion smear and blurred images when ordinary industrial cameras are used to shoot high-speed rotating blades, but also enhances the image features and ensures the reliability of image matching at the detection point, thereby being able to accurately and efficiently detect the strain law of the blade during operation, providing key technical support for improving the thrust and safety performance of aircraft engines.

[0019] Furthermore, the reflective digital laser sensor includes a laser probe and a signal amplifier. The laser beam width is controlled to a spot beam width by adjusting the exit port of the laser probe, and the reflected light intensity threshold is set by the amplifier to generate a trigger level signal.

[0020] Specifically, the reflective digital laser sensor includes a laser probe and a signal amplifier. By adjusting the exit port of the laser probe, the laser beam width can be precisely controlled to a spot beam width. Such a spot beam laser has more concentrated energy and can more accurately aim at the reflective sticker on the blade, reducing false triggering caused by the laser beam being too wide and irradiating non-reflective areas. For example, during high-speed rotation of the blade, a wider laser beam may simultaneously irradiate the reflective sticker and other surfaces of the blade, while the spot beam laser can effectively avoid such interference. At the same time, the amplifier sets the reflected light intensity threshold to generate a trigger level signal. The threshold can be flexibly adjusted according to factors such as the lighting conditions in the actual measurement environment and the reflective performance of the reflective sticker, ensuring that the signal is triggered only when the laser accurately irradiates the reflective sticker and the reflected light intensity reaches the set standard. This avoids false triggering due to external stray light or insufficient reflected light intensity, thereby ensuring the accuracy of the trigger signal and providing a more reliable guarantee for the high-speed camera to accurately capture blade images at a specific phase, thereby improving the stability of the blade deformation field measurement.

[0021] Furthermore, the reflective tape is attached to adjacent blades of the blade being measured to avoid blocking the speckle area on the surface of the blade being measured.

[0022] Specifically, the present invention affixes reflective tape to adjacent blades to the measured blade, effectively preventing the reflective tape from obstructing the speckle area on the measured blade's surface, thereby ensuring that the speckle area image captured by the high-speed camera is complete and clear. The speckle area is crucial for grayscale feature matching using digital image correlation methods. If the reflective tape is directly affixed to the measured blade, it may cover some of the speckle, resulting in missing feature points during matching and affecting the accuracy of deformation field calculation. For example, when a high-speed camera captures an image at a specific phase, if the reflective tape obscures the speckle pattern of the measured blade, subsequent comparison of the before-and-after deformation images using digital image correlation methods will result in matching errors due to incomplete key feature information, further affecting the accuracy of blade deformation measurement. Placing the reflective tape adjacent to the blade ensures that the laser irradiation triggers the sensor to output a level signal, enabling accurate capture of the specific phase. It also allows the speckle area of ​​the measured blade to be fully exposed in the camera's field of view, providing a complete image feature foundation for accurate calculation of the blade deformation field and further improving measurement reliability.

[0023] Furthermore, before executing S1, speckles are artificially sprayed on the surface of the blade, and the speckle area is used for grayscale feature matching in the digital image correlation method.

[0024] Specifically, before performing the measurement step, speckle patterns are artificially sprayed on the blade surface. These speckle regions can provide rich and clear grayscale features for the digital image correlation method, significantly improving the accuracy and reliability of image matching. The core of the digital image correlation method is to calculate deformation by comparing the grayscale distribution of the same area in the image before and after deformation. If the blade surface lacks obvious natural features, misjudgment or insufficient accuracy can easily occur during the matching process. For example, when the blade surface is relatively smooth, the grayscale changes are not obvious. Even if deformation occurs, it is difficult to accurately capture its displacement and strain through the image. However, the artificially sprayed speckle forms a large number of unique grayscale feature points, which are like "marking" the blade surface, allowing the image captured by the high-speed camera to clearly identify the corresponding area before and after deformation. These speckle regions serve as stable feature carriers, ensuring that matching areas can be accurately found when calculating the blade deformation field, reducing errors caused by blurred or missing features, and laying a solid foundation for the subsequent accurate analysis of the blade's strain pattern.

[0025] Furthermore, in S3, the exposure time of the high-speed camera is shorter than the blade rotation period to ensure that the captured image is free of motion smear; the acquisition process needs to be accompanied by high-brightness light source illumination to enhance the grayscale characteristics of the speckle area.

[0026] Specifically, when collecting blade images, the exposure time of the high-speed camera is set to be much shorter than the blade rotation period. This approach can effectively avoid the motion drag caused by the high-speed rotation of the blade and ensure that the collected image clearly presents the speckle details on the blade surface. For example, if the blade rotation period is 10 milliseconds, controlling the camera exposure time to less than 20 microseconds can "freeze" its instantaneous state during the blade rotation process, avoiding blurred tracks in the image, and allowing the edges and grayscale features of the speckle to be clearly captured. At the same time, the use of high-brightness light source illumination during the acquisition process can significantly enhance the grayscale features of the speckle area. Even when the blade surface is unevenly reflective or the ambient light is dim, the speckle can form a clear grayscale contrast with the surrounding area, providing clearer and more recognizable image information for subsequent digital image correlation method grayscale feature matching, reducing matching errors caused by unclear features, and further improving the accuracy of blade deformation field measurement.

[0027] Furthermore, in S3, the shooting cycle of the high-speed camera is synchronized with the blade rotation cycle, so that each frame of the collected image corresponds to the same phase of the blade rotation, which is convenient for subsequent image matching and tracking.

[0028] Specifically, when collecting blade images, this embodiment synchronizes the shooting cycle of the high-speed camera with the blade rotation cycle. In this way, each frame of the image collected can accurately correspond to the same phase of the blade rotation, which greatly facilitates subsequent image matching and tracking. For example, if the blade rotates 1000 times per second and its rotation cycle is 1 millisecond, then the shooting cycle of the high-speed camera is also set to 1 millisecond. Each shot can capture the state of the blade in the same rotation position, avoiding image phase confusion caused by the shooting timing being out of sync with the blade rotation. This synchronization ensures that the images before and after deformation are consistent in phase. When matching using the digital image correlation method, the speckle features of the corresponding area can be found more accurately, reducing the matching error caused by phase deviation, thereby improving the reliability and accuracy of the blade deformation field measurement, and making the analysis of the blade deformation law more accurate and effective.

[0029] Furthermore, in S3, when the blade is in a non-specific phase, the high-speed camera does not trigger acquisition, and only the continuous image sequence of the same phase is retained for deformation analysis.

[0030] Specifically, when the blade is in a non-specific phase, the high-speed camera is controlled not to collect images, and only the continuous image sequence of the same phase is retained for deformation analysis. This can effectively reduce the interference of invalid image data and make the subsequent deformation analysis more targeted and accurate. For example, when the blade is rotating at high speed, the high-speed camera will be triggered to shoot only when it rotates to a preset specific phase, and no images are collected at other phases. This avoids the storage and processing of a large number of non-target phase images, which not only saves storage resources and computing costs, but also ensures that the images used for analysis are from the same phase, reducing matching errors caused by phase inconsistency. The continuous image sequence of the same phase can clearly reflect the deformation process of the blade in that phase, so that when the deformation field is calculated by the digital image correlation method, the subtle changes of the blade can be captured more accurately, further improving the reliability and efficiency of the blade deformation measurement, and providing more effective data support for the accurate evaluation of the strain law of the blade.

[0031] Furthermore, in S4, when matching the acquired images, the strain field is calculated and the background noise is filtered by comparing the grayscale distribution difference of the speckle area of ​​the same phase image before and after deformation.

[0032] Specifically, when matching the acquired images, the strain field is calculated by comparing the grayscale distribution differences in the speckle region of the same phase image before and after deformation, and background noise is filtered. This significantly improves the accuracy and reliability of blade deformation measurement. Digital image correlation methods rely on matching grayscale features in images to obtain deformation information. However, actual acquired images inevitably contain background noise due to factors such as light fluctuations and sensor noise. This noise interferes with the accurate identification of grayscale distribution differences, thereby affecting the accuracy of strain field calculation. For example, when the grayscale changes in the speckle region are subtle, background noise may mask the true deformation characteristics, resulting in matching errors. However, filtering background noise can highlight the true grayscale changes in the speckle region caused by blade deformation, making the comparison more accurate. Furthermore, focusing on the same phase for comparison ensures spatial correspondence between the images before and after deformation, reducing additional errors caused by phase asynchrony. This allows the calculated strain field to more accurately reflect the blade's deformation state, providing more precise data support for blade deformation monitoring and risk assessment.

[0033] A storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering.

[0034] Specifically, the storage medium provided in this embodiment stores a computer program. When the computer program is executed by the processor, the above-mentioned high-speed blade deformation measurement method of large-scale rotating equipment based on laser synchronous triggering can be implemented. This allows the measurement method to be easily deployed and run on different computer devices, thereby improving the portability and practicality of the method. For example, after researchers develop and verify the method on a computer in the laboratory, they can transfer the program to the detection equipment at the production site through the storage medium without having to repeatedly write code, thereby reducing manpower and time costs. At the same time, the storage medium can stably save the program, ensuring that the various steps and parameter settings of the measurement method are accurately retained, avoiding method execution deviations caused by differences in manual operations, and thus ensuring that when the measurement method is applied in different scenarios, stable and consistent measurement results can be obtained, providing a more flexible and reliable implementation method for blade deformation detection.

[0035] A computer device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement the above-mentioned method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering.

[0036] Specifically, the computer device provided in this embodiment includes a memory, a processor, and a computer program stored in the memory. When the processor executes the program, it can realize the above-mentioned large-scale rotating equipment high-speed blade deformation measurement method based on laser synchronous triggering, which provides a hardware carrier for the practical application of the measurement method, so that the method can run stably and efficiently. For example, in the production inspection line or scientific research experiment of aircraft engine blades, the computer device can be directly connected to the measurement system, and the program can be called by the processor to control the reflective digital laser sensor, high-speed camera and other equipment to work together according to the set steps to complete the measurement and analysis of blade deformation without relying on complex external environment configuration. At the same time, the memory can reliably store the program and the collected image data, and the processor ensures the speed and accuracy of the calculation process, ensuring that the entire process from laser triggering, image acquisition to deformation field calculation is carried out smoothly, thereby providing an integrated solution for blade deformation detection and improving the convenience and reliability of the measurement work.

[0037] The present invention provides a high-speed blade deformation measurement method for large-scale rotating equipment based on laser synchronous triggering. It addresses the problems existing in the visual measurement of the deformation field of high-speed rotating blades, such as the difficulty in locking the rotational phase, the failure of image matching caused by phase deviation, and image blur caused by motion smear when shooting with ordinary industrial cameras. By adopting a laser synchronous triggering scheme, that is, using a reflective digital laser sensor in combination with a high-speed camera, combined with the reflective sticker on the blade, it can realize the precise capture of the blade image of a specific phase, and at the same time enhance the image features with the help of artificial spraying speckle, effectively improving the stability and accuracy of the blade deformation field measurement, ensuring the reliability of the image matching of the detection point, and providing strong support for the accurate and efficient detection of the strain law of the blade during operation.

[0038] While the specific embodiments of the present invention have been described in detail above, these are intended to be exemplary only, and the present invention is not limited thereto. Any equivalent modifications or substitutions to the present invention that would be apparent to those skilled in the art are also within the scope of the present invention. Therefore, any equivalent modifications or substitutions made without departing from the spirit and scope of the present invention are intended to be encompassed within the scope of the present invention.

Claims

1. A method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering, characterized in that: The following steps are involved: S1, emits a spot laser beam to the high-speed rotating blade through a reflective digital laser sensor; S2. When the blade rotates to a specific phase, the spot laser beam irradiates the reflective sticker on the blade surface. The reflected light intensity exceeds the set threshold, triggering the sensor to output a level signal. S3, using the level signal as an external trigger signal to control the high-speed camera to collect the speckle area image on the blade surface at the specific phase; S4. Based on the speckle area image, the blade deformation field is calculated by digital image correlation method.

2. The method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering according to claim 1 is characterized in that: The reflective digital laser sensor includes a laser probe and a signal amplifier. The laser beam width is controlled to the spot beam width by adjusting the exit port of the laser probe, and the reflected light intensity threshold is set through the amplifier to generate a trigger level signal.

3. The method for measuring high-speed blade deformation of large rotary equipment based on laser synchronous triggering according to claim 2 is characterized in that: The reflective tape is pasted on the adjacent blade of the blade being measured.

4. The method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering according to claim 3 is characterized in that: Before executing S1, speckles are artificially sprayed on the blade surface, and the speckle area is used for grayscale feature matching in the digital image correlation method.

5. The method for measuring high-speed blade deformation of large rotary equipment based on laser synchronous triggering according to claim 4 is characterized in that: In S3, the exposure time of the high-speed camera is shorter than the blade rotation period; the acquisition process requires the use of a high-brightness light source.

6. The method for measuring high-speed blade deformation of large rotary equipment based on laser synchronous triggering according to claim 5 is characterized in that: In S3, the shooting cycle of the high-speed camera is synchronized with the blade rotation cycle, so that each frame of the collected image corresponds to the same phase of the blade rotation.

7. The method for measuring high-speed blade deformation of large rotary equipment based on laser synchronous triggering according to claim 6 is characterized in that: In S3, when the blade is in a non-specific phase, the high-speed camera does not trigger acquisition, and only the continuous image sequence of the same phase is retained for deformation analysis.

8. The method for measuring high-speed blade deformation of large rotary equipment based on laser synchronous triggering according to claim 7 is characterized in that: In S4, when matching the acquired images, the strain field is calculated and the background noise is filtered by comparing the grayscale distribution difference of the speckle area of ​​the same phase image before and after deformation.

9. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering according to any one of claims 1 to 8 is implemented.

10. A computer device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for measuring high-speed blade deformation of large-scale rotating equipment based on laser synchronous triggering as described in any one of claims 1 to 8.

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