Aero-engine image acquisition system based on bionic snake bone endoscope structure

Abstract

The invention discloses an aero-engine image acquisition system based on a bionic snake bone endoscope structure, which relates to the technical field of aero-engine detection and comprises a flexible bionic snake bone carrier, a multispectral imaging module, an active anti-shake compensation module, an anti-electromagnetic interference transmission link, a self-adaptive exposure control module and an image processing terminal. According to the method, the multispectral imaging and three-dimensional point cloud fusion technology is adopted, surface cracks, internal ablation and micron-sized lubricating oil residues of the aero-engine can be detected at the same time, the defect detection rate is increased, meanwhile, the residual life of engine parts can be accurately evaluated in combination with a thermal-mechanical coupling analysis result, and the reliability of the aero-engine is improved. High-precision real-time anti-shake is achieved through the gyroscope and the piezoelectric ceramic displacement device, vibration fuzzy can be effectively reduced, interference of strong light smoke can be overcome through self-adaptive exposure control based on a double-weight optimization strategy, the signal-to-noise ratio of the smoke environment is increased, high-precision three-dimensional reconstruction is achieved in combination with laser scanning and a phase deviation method, and the system is high in practicability and high in practicability. And the point cloud generation speed and the three-dimensional modeling efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine detection, and in particular to an aero-engine image acquisition system based on a bionic snake-bone endoscope structure. Background Art

[0002] An industrial endoscope is a device that uses optical and electronic technology to perform non-destructive testing on the inside of an object. It uses a probe to enter the interior of the device and obtain real-time images without disassembling or destroying the object being inspected. It is widely used in aerospace, petrochemical, automobile manufacturing, electric power, machinery manufacturing and other fields to detect internal defects and ensure quality and safety.

[0003] Aircraft engine image acquisition refers to the use of high-resolution cameras, 3D cameras, endoscopes and other equipment to obtain high-precision images or three-dimensional data inside and outside the engine, thereby achieving high-precision inspection and measurement of key components, inspection of complex surfaces and blind spots, real-time monitoring and early warning, defect identification and assessment, maintenance and repair guidance, as well as foreign matter detection and removal. By correctly selecting and using industrial endoscopes and aircraft engine image acquisition systems, it is possible to effectively improve inspection efficiency and accuracy and ensure the safety of equipment and personnel.

[0004] Traditional aircraft engine image acquisition technology uses single spectral imaging, which cannot simultaneously detect surface damage and sub-surface defects, resulting in a high rate of missed detection of cracks and oil stains. In addition, image acquisition in a high-frequency vibration environment lacks real-time micron-level anti-shake means, and image blurring is seriously deteriorated. In addition, strong light flicker and kerosene combustion carbon soot can easily cause traditional automatic exposure to fail, and the signal-to-noise ratio is low under smoke. At the same time, due to the complex cavity structure of the aircraft engine, the traditional visual three-dimensional reconstruction point cloud has a high void rate, large positioning error, low image acquisition efficiency, and low damage diagnosis accuracy. Therefore, the present invention proposes an aircraft engine image acquisition system based on a bionic snake bone endoscope structure to solve the problems existing in the prior art. Summary of the Invention

[0005] In response to the above problems, the purpose of the present invention is to propose an aircraft engine image acquisition system based on a bionic snake bone endoscope structure, which solves the bottleneck problems of traditional aircraft engine detection such as insufficient flexibility, poor environmental adaptability, low efficiency, low intelligence level and need to improve accuracy.

[0006] In order to achieve the objectives of the present invention, the present invention is implemented through the following technical solutions: an aircraft engine image acquisition system based on a bionic snake bone endoscope structure, including a flexible bionic snake bone carrier and an image processing terminal, the flexible bionic snake bone carrier is integrated with a multispectral imaging module and an active anti-shake compensation module, the image processing terminal is equipped with an adaptive exposure control module, the flexible bionic snake bone carrier is composed of a segmented hinged titanium alloy snake bone joint, with a built-in fiber optic image transmission bundle, an illumination fiber and a drive cable, the multispectral imaging module includes a visible light sensor, a short-wave infrared sensor and an ultraviolet fluorescence excitation unit integrated at the front end of the flexible bionic snake bone carrier, the active anti-shake compensation unit includes a gyroscope and a piezoelectric ceramic displacer, and uses a vibration suppression algorithm to correct the image offset caused by mechanical vibration in real time, the adaptive exposure control module adjusts the lighting intensity and sensor exposure parameters through closed-loop feedback based on the dynamic lighting environment in the engine cavity, and the image processing terminal is used to perform aircraft engine damage feature recognition and three-dimensional point cloud reconstruction.

[0007] Further improvements are: the surface of the flexible bionic snake-bone carrier is coated with a polytetrafluoroethylene wear-resistant layer, and the drive cable is made of carbon fiber reinforced nylon composite material.

[0008] Further improvements are: the operating band of the multispectral imaging module is 400-1700nm, the short-wave infrared sensor uses a mercury cadmium telluride focal plane array, and the ultraviolet fluorescence excitation unit emits 365nm ultraviolet light to detect engine lubricating oil residue and microcracks through fluorescence response.

[0009] Further improvements are: the vibration suppression algorithm of the active anti-shake compensation unit adopts adaptive Kalman filtering, the sampling frequency is ≥5kHz, and the response time of the piezoelectric ceramic displacer is ≤0.1ms.

[0010] A further improvement is that the front end of the flexible bionic snake bone carrier is also integrated with a laser scanning positioning module, which uses a VCSEL array laser to calculate the three-dimensional morphology through a phase shift method.

[0011] A further improvement is that the laser scanning positioning module works in conjunction with the image processing terminal to map the two-dimensional image data to a three-dimensional engine coordinate system through a feature point matching algorithm.

[0012] Further improvements are as follows: the image processing terminal includes a data fusion module, an online deep learning diagnosis module and a life prediction module. The data fusion module fuses multimodal data and generates an RGB-D fusion map. The online deep learning diagnosis module detects cracks, ablation and coating peeling in real time. The life prediction module combines the thermal-mechanical coupling analysis results with historical detection data to generate a remaining service life probability distribution curve.

[0013] A further improvement is that it also includes an electromagnetic interference resistant transmission link, and the electromagnetic interference resistant transmission link adopts a differential signal transmission method.

[0014] A further improvement is that the adaptive exposure control module adopts a dual-weight optimization strategy: the first weight is based on the principle of maximizing image entropy value, dynamically adjusting the LED drive current of the illumination fiber, and the second weight is combined with the smoke scattering model to invert the optimal exposure time through the Monte Carlo algorithm. The adaptive exposure control module has a built-in ambient light intensity calibration database that covers the spectral characteristics of aviation kerosene combustion products.

[0015] A further improvement is that the flexible bionic snake bone carrier is composed of a front end portion of the snake bone, a segmented hinged titanium alloy snake bone joint and a rear end portion of the snake bone, and the flexible bionic snake bone carrier has a built-in optical fiber imaging bundle, an illumination optical fiber and a drive cable.

[0016] The beneficial effects of the present invention are as follows: the present invention adopts multispectral imaging and three-dimensional point cloud fusion technology, which can simultaneously detect surface cracks, internal ablation and micron-level lubricating oil residues of aircraft engines, achieve full-dimensional defect coverage, and improve the defect detection rate. At the same time, combined with the results of thermal coupling analysis, it can accurately evaluate the remaining life of engine components, and achieve high-precision real-time anti-shake through gyroscopes and piezoelectric ceramic displacers, which can effectively reduce vibration blur and realize displacement compensation. The adaptive exposure control based on the dual-weight optimization strategy can overcome the interference of strong light and dust, improve the signal-to-noise ratio of the dust environment, and reduce the occurrence rate of overexposure or underexposure. In addition, the combination of laser scanning and phase shift method realizes high-precision three-dimensional reconstruction, improves the point cloud generation speed and three-dimensional modeling efficiency, and improves the image acquisition and damage identification efficiency of aircraft engines to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of an aircraft engine image acquisition system based on a bionic snake bone endoscope structure according to the present invention;

[0018] Figure 2 It is a schematic diagram of the flexible bionic snake bone carrier of the present invention.

[0019] Among them: 101, the front end of the snake bone; 102, the titanium alloy snake bone joint; 103, the rear end of the snake bone; 104, the fiber optic imaging bundle; 105, the lighting fiber; 106, the drive cable. DETAILED DESCRIPTION

[0020] 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.

[0021] The working principle of industrial endoscopes is based on optical imaging, mechanical transmission and electronic image processing. Through the optical lens in the probe, the light inside the inspected object is focused onto the CCD or CMOS sensor, and the optical signal is converted into an electrical signal. Mechanical transmission enables the probe to bend and rotate flexibly to adapt to different observation angles and complex internal structures. Electronic image processing technology processes the captured image to improve clarity and recognizability, and transmits it to the display device via cable or wirelessly for observation and analysis.

[0022] Aviation engine image acquisition systems use high-resolution cameras, 3D cameras, industrial endoscopes and other equipment to obtain high-precision images or three-dimensional data inside and outside the engine. These systems use structured light, binocular vision, time-of-flight (TOF) and other technologies to capture key parameters such as the shape, size, and surface features of components.

[0023] according to Figure 1 As shown, this embodiment provides an aircraft engine image acquisition system based on a bionic snake-bone endoscope structure. The system consists of a flexible bionic snake-bone carrier, a multispectral imaging module, an active anti-shake compensation module, an anti-electromagnetic interference transmission link, an adaptive exposure control module, and an image processing terminal. The multispectral imaging module and the active anti-shake compensation module are integrated on the flexible bionic snake-bone carrier, and the adaptive exposure control module is mounted on the image processing terminal. The anti-electromagnetic interference transmission link adopts a differential signal transmission method to achieve lossless image data transmission of ≥1Gbps in the engine operating environment, providing a stable data transmission path, wherein:

[0024] The flexible bionic snake-bone carrier consists of a front end portion 101 of the snake-bone, a segmented hinged titanium alloy snake-bone joint 102, and a rear end portion 103 of the snake-bone. The flexible bionic snake-bone carrier has a built-in fiber optic imaging bundle 104, an illumination fiber 105, and a drive cable 106. The flexible bionic snake-bone carrier has a bending radius of ≤3mm and an axial torsional stiffness of ≥5N·m / rad, adapting to high-precision navigation in the narrow and curved cavity of an aircraft engine. The flexible bionic snake-bone carrier of this embodiment adopts a gradient stiffness design, with the proximal joint stiffness (8N·m / rad) being higher than the distal joint stiffness (3N·m / rad), adapting to the mechanical requirements from the entrance to the deep area of ​​the engine cavity.

[0025] The multispectral imaging module consists of a visible light sensor for detecting the internal surface morphology of aircraft engines, a short-wave infrared sensor for detecting internal defects of aircraft engines, and an ultraviolet fluorescence excitation unit for detecting and identifying lubricant residue and microcracks. All of these are integrated into the front end of the flexible bionic snake-bone carrier.

[0026] The active anti-shake compensation unit consists of a gyroscope and a piezoelectric ceramic displacer. It uses a vibration suppression algorithm to correct image deviation caused by mechanical vibration in real time. The gyroscope uses a six-axis MEMS gyroscope, and the piezoelectric ceramic displacer uses a lead zirconate titanate (PZT) piezoelectric ceramic displacer.

[0027] The adaptive exposure control module adjusts the lighting intensity and sensor exposure parameters through closed-loop feedback based on the dynamic lighting environment in the engine cavity;

[0028] The image processing terminal is deployed on an edge computing device (NVIDIA Jetson AGX Orin), supports TensorRT acceleration, and has an inference speed of ≥30FPS. It is used to perform aircraft engine damage feature recognition and 3D point cloud reconstruction.

[0029] In this embodiment, the surface of the flexible bionic snake bone carrier is coated with a polytetrafluoroethylene wear-resistant layer, the friction coefficient is ≤0.1, and the wear resistance life is ≥100,000 bending cycles. The drive cable is made of carbon fiber reinforced nylon composite material with a tensile strength of ≥800MPa and fatigue resistance better than 107 cycles, which significantly improves the durability of the equipment.

[0030] In this embodiment, the operating band of the multispectral imaging module is 400 to 1700 nm, the short-wave infrared sensor uses a mercury cadmium telluride (HgCdTe) focal plane array with a resolution of ≥1280×1024 pixels and a frame rate of ≥30fps. The ultraviolet fluorescence excitation unit emits 365nm ultraviolet light to detect engine lubricating oil residue and microcracks through fluorescence response.

[0031] In this embodiment, the vibration suppression algorithm of the active anti-shake compensation unit adopts adaptive Kalman filtering, with a sampling frequency of ≥5kHz, a displacement compensation accuracy of ±2μm, a response time of the piezoelectric ceramic displacer of ≤0.1ms, and a maximum compensation displacement of ±200μm, eliminating high-frequency vibration interference during engine operation.

[0032] In this embodiment, the front end of the flexible bionic snake bone carrier is also integrated with a laser scanning positioning module. The laser scanning positioning module adopts a VCSEL array laser to project Gray code structured light with a wavelength of 850nm. The three-dimensional morphology is calculated by the phase shift method. The point cloud density is ≥500,000 points / second, and the three-dimensional coordinates inside the aircraft engine are generated in real time. The laser scanning positioning module works in coordination with the image processing terminal to map the two-dimensional image data to the three-dimensional engine coordinate system through the feature point matching algorithm.

[0033] In this embodiment, the image processing terminal includes a data fusion module for fusing multimodal data, an online deep learning diagnosis module for real-time damage monitoring, and a life prediction module for predicting the remaining life of an aircraft engine. The data fusion module aligns visible light, infrared, and three-dimensional point cloud data in time and space to generate an RGB-D fusion map. The online deep learning diagnosis module is based on a lightweight Transformer network and detects cracks (accuracy ≥ 99.5%), ablation (sensitivity ≥ 98%), and coating peeling (recall rate ≥ 97%) in real time. The life prediction module combines the results of thermal-mechanical coupling analysis with historical detection data, fuses infrared and visible light data to generate a temperature-deformation superposition map, evaluates the thermal fatigue state of components, and generates a remaining useful life (RUL) probability distribution curve to support maintenance decisions.

[0034] In this embodiment, the adaptive exposure control module adopts the following dual-weight optimization strategy:

[0035] First weight: Based on the principle of maximizing image entropy, dynamically adjust the LED driving current (0-500mA) of the illumination fiber;

[0036] Second weight: Combined with the smoke scattering model, the optimal exposure time (1μs to 1s) is inverted through the Monte Carlo algorithm;

[0037] The adaptive exposure control module has a built-in ambient light intensity calibration database that covers the spectral characteristics of aviation kerosene combustion products and adapts to the complex lighting environment of aviation kerosene combustion products.

[0038] When the aero-engine image acquisition system based on the bionic snake-bone endoscope structure is actually used:

[0039] First, an operator controls the flexible bionic snake-bone carrier to enter the narrow cavity inside the aircraft engine. The titanium alloy snake-bone joints work in conjunction with the drive cables to achieve flexible steering with a bending radius of ≤3mm. The laser scanning positioning module projects structured laser stripes in real time and, combined with binocular vision, generates a 3D coordinate map of the aircraft engine's interior to assist in path planning.

[0040] At the same time, the multispectral imaging module is activated synchronously, using visible light sensors to capture surface defects (such as cracks and scratches) within the aircraft engine, short-wave infrared sensors to detect internal thermal anomalies and ablation areas within the aircraft engine, and ultraviolet fluorescence excitation units to stimulate lubricant residue or microcracks to produce fluorescence signals.

[0041] Secondly, the active anti-shake compensation module senses vibrations through a gyroscope and uses piezoelectric ceramic micro-displacers to compensate for image deviations in real time with an accuracy of ±2μm to ensure clear images.

[0042] Subsequently, the adaptive exposure control module dynamically analyzes the environment, adjusts the LED lighting intensity (0 to 500 mA) based on the aircraft engine smoke concentration, and optimizes the sensor exposure time (1 μs to 1 second) based on temperature data;

[0043] During the entire image acquisition process, an electromagnetic interference-resistant transmission link is used to transmit multispectral images and 3D point cloud data to the image processing terminal at a rate of 1Gbps;

[0044] The data processing terminal then performs data processing tasks, fusing visible light, infrared, and 3D data to generate an RGB-D fusion atlas. It then uses the Transformer network to identify blade cracks (with an accuracy of ≥99.5%) and ablation areas in real time, annotating the risk levels. Combined with the results of the thermal-mechanical coupling analysis, it outputs a remaining useful life probability curve.

[0045] Finally, the laser scanning and positioning module continuously updates the internal three-dimensional model of the aircraft engine, compares it with the preset CAD model, and automatically marks dimensional deviations. The detection results are superimposed and displayed through AR equipment, guiding maintenance personnel to accurately locate the fault point and realize the image acquisition and damage diagnosis of the entire aircraft engine.

[0046] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. An aero-engine image acquisition system based on a bionic snake-bone endoscope structure, comprising a flexible bionic snake-bone carrier and an image processing terminal, characterized in that: The flexible bionic snake-bone carrier is integrated with a multispectral imaging module and an active anti-shake compensation module; the image processing terminal is equipped with an adaptive exposure control module; the multispectral imaging module includes a visible light sensor, a short-wave infrared sensor, and an ultraviolet fluorescence excitation unit integrated at the front end of the flexible bionic snake-bone carrier; the active anti-shake compensation unit includes a gyroscope and a piezoelectric ceramic displacer, and adopts a vibration suppression algorithm to correct the image offset caused by mechanical vibration in real time; the adaptive exposure control module adjusts the lighting intensity and sensor exposure parameters through closed-loop feedback based on the dynamic lighting environment in the engine cavity; the image processing terminal is used to perform aircraft engine damage feature recognition and three-dimensional point cloud reconstruction.

2. The aero-engine image acquisition system based on the bionic snake-bone endoscope structure according to claim 1, characterized in that: The surface of the flexible bionic snake-bone carrier is coated with a polytetrafluoroethylene wear-resistant layer, and the driving cable is made of carbon fiber reinforced nylon composite material.

3. The aero-engine image acquisition system based on the bionic snake-bone endoscope structure according to claim 1 is characterized in that: The multispectral imaging module operates in a wavelength range of 400 to 1700 nm. The short-wave infrared sensor uses a mercury cadmium telluride focal plane array. The ultraviolet fluorescence excitation unit emits 365 nm ultraviolet light to detect engine lubricating oil residue and microcracks through fluorescence response.

4. The aero-engine image acquisition system based on a bionic snake-bone endoscope structure according to claim 1, characterized in that: The vibration suppression algorithm of the active anti-shake compensation unit adopts adaptive Kalman filtering, the sampling frequency is ≥5kHz, and the response time of the piezoelectric ceramic displacer is ≤0.1ms.

5. The aircraft engine image acquisition system based on the bionic snake bone endoscope structure according to claim 1 is characterized in that: The front end of the flexible bionic snake bone carrier is also integrated with a laser scanning positioning module, which uses a VCSEL array laser to calculate the three-dimensional morphology through a phase shift method.

6. The aircraft engine image acquisition system based on the bionic snake bone endoscope structure according to claim 5, characterized in that: The laser scanning positioning module works in conjunction with the image processing terminal to map the two-dimensional image data to a three-dimensional engine coordinate system through a feature point matching algorithm.

7. The aircraft engine image acquisition system based on the bionic snake bone endoscope structure according to claim 1 is characterized by: The image processing terminal includes a data fusion module, an online deep learning diagnosis module and a life prediction module. The data fusion module fuses multimodal data and generates an RGB-D fusion map. The online deep learning diagnosis module detects cracks, ablation and coating shedding in real time. The life prediction module combines the results of thermal-mechanical coupling analysis with historical detection data to generate a remaining service life probability distribution curve.

8. The aero-engine image acquisition system based on a bionic snake-bone endoscope structure according to claim 1, characterized in that: It also includes an anti-electromagnetic interference transmission link, which adopts a differential signal transmission method.

9. The aircraft engine image acquisition system based on the bionic snake bone endoscope structure according to claim 1, characterized in that: The adaptive exposure control module adopts a dual-weight optimization strategy: the first weight is based on the principle of maximizing image entropy value, dynamically adjusting the LED drive current of the illumination fiber. The second weight is combined with the smoke scattering model and uses the Monte Carlo algorithm to invert the optimal exposure time. The adaptive exposure control module has a built-in ambient light intensity calibration database that covers the spectral characteristics of aviation kerosene combustion products.

10. The aero-engine image acquisition system based on the bionic snake-bone endoscope structure according to claim 1, characterized in that: The flexible bionic snake bone carrier consists of a snake bone front end portion (101), a segmented hinged titanium alloy snake bone joint (102) and a snake bone rear end portion (103). The flexible bionic snake bone carrier is equipped with a built-in optical fiber imaging bundle (104), an illumination optical fiber (105) and a drive cable (106).

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