A laser holographic full-dimension detection method for aviation gears

Abstract

The present application relates to a kind of laser holographic aviation gear full-dimension detection method.Currently, traditional optical measurement needs to manually adjust gear posture multiple times to obtain different angle images, and single detection needs to replace multiple fixtures and measurement parameters, which is complex and time-consuming, and difficult to adapt to the quality inspection efficiency requirements of mass production, and there is potential damage to the gear.The present application includes gear positioning and fixing, scanning parameter adaptation, according to the tooth shape type and material characteristics of aviation gear, the laser wavelength, emission power and spot size of laser holographic emission module are set, panoramic scanning path planning, holographic signal acquisition and processing, and defect identification and result output, through the cooperative process of laser holographic scanning path planning, multidimensional signal acquisition and holographic image intelligent analysis, the non-contact panoramic detection of aviation gear tooth surface precision, gear meshing state and internal microscopic defects is realized.The present application is applied to the technical field of aviation parts detection.

Description

Technical Field

[0001] This invention belongs to the field of aviation component inspection technology, and in particular relates to a laser holographic method for full-dimensional inspection of aviation gears. Background Technology

[0002] Aviation gears are key components of core parts such as aero engines and transmission systems. Their quality directly determines the operational safety and reliability of aviation equipment, therefore, the requirements for their inspection accuracy and comprehensiveness are extremely high. Currently, the mainstream methods for inspecting aviation gears are mainly contact measurement (such as coordinate measuring machines) and traditional optical measurement. Among them, contact measurement relies on the physical contact between the probe and the tooth surface, which is difficult to cover complex curved surfaces such as tooth root fillets and tooth meshing surfaces, and cannot penetrate the surface of the gear to detect internal micro-defects, which can easily leave hidden safety hazards. Currently, traditional optical measurement requires multiple manual adjustments to the gear posture to obtain images from different angles. A single inspection requires changing multiple fixtures and measurement parameters, making the operation complex and time-consuming. This is difficult to adapt to the quality inspection efficiency requirements of mass production and poses potential damage to the gears: the pressure of the probe in contact measurement may cause micro-deformation of lightweight aerospace gears (such as titanium alloy gears), affecting measurement accuracy and potentially causing wear on the gear surface coating.

[0003] Laser holography technology has been gradually applied in the field of precision parts inspection due to its advantages of non-contact, high resolution and three-dimensional imaging. However, existing laser holographic inspection methods are mostly for simple structure workpieces, lack scanning path planning schemes adapted to the complex tooth profile of aerospace gears, and cannot achieve synchronous panoramic inspection of the outer contour and internal structure of gears. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of traditional optical measurement requiring multiple manual adjustments of gear posture to obtain images from different angles, and the need to change multiple fixtures and measurement parameters for a single inspection, which is complex and time-consuming. Therefore, this invention provides a laser holographic method for full-dimensional inspection of aerospace gears.

[0005] A laser holographic method for full-dimensional detection of aircraft gears, comprising the following steps: Step 1: Gear positioning and fixing: The aircraft gear to be tested is installed on an adjustable positioning platform. The gear is positioned by the center hole and limited in the circumferential direction to ensure that the rotation axis of the gear coincides with the reference axis of the positioning platform. Step 2: Scanning parameter adaptation: Based on the tooth profile and material properties of aircraft gears, the laser wavelength, emission power, and spot size of the laser holographic emission module are set; Step 3: Panoramic Scan Path Planning: The control and positioning platform drives the gear to rotate at a constant speed, and synchronously adjusts the spatial position of the laser emission module to form a spiral scanning path covering the gear tooth tip, tooth surface, tooth root and end face; Step 4: Holographic Signal Acquisition and Processing The laser holographic signal reflected from the gear surface is received in real time, and a three-dimensional holographic image of the gear is reconstructed through a phase demodulation algorithm to generate panoramic data containing the outer contour and internal structure of the gear. Step 5: Defect Identification and Result Output: By comparing panoramic data with a preset standard parameter model of aviation gears, defects such as tooth surface wear, tooth cracks and internal porosity are automatically identified, and an inspection report on the location and type of defects is output.

[0006] Furthermore, according to the aforementioned step one, the positioning platform is equipped with a coaxiality calibration component. By monitoring the radial runout during gear rotation in real time, the positioning fixture is dynamically adjusted to ensure gear rotation stability.

[0007] Furthermore, in step three, during the panoramic scanning path planning, the moving speed of the laser emission module is matched with the rotation speed of the gear to ensure the overlap rate of adjacent scanning trajectories and avoid scanning blind spots.

[0008] Furthermore, based on the holographic signal acquisition and processing in step four, an adaptive filtering algorithm is used to denoise the acquired laser holographic signal, thereby improving the detail clarity of the three-dimensional holographic image.

[0009] Furthermore, the standard parameter model preset in step five for defect identification and result output can be updated according to the design requirements of different types of aircraft gears to adapt to the inspection needs of multiple specifications of gears.

[0010] Furthermore, according to the scanning parameters in step two, the tooth type of the aircraft gear is spur, helical, or bevel.

[0011] The laser holographic method for full-dimensional detection of aircraft gears proposed in this invention can bring the following beneficial effects: This invention provides a method for inspecting aerospace spur gears, enabling full-dimensional inspection without gear disassembly. The inspection process is non-contact and non-destructive, avoiding the micro-deformation problems associated with traditional contact measurements. The entire inspection process eliminates the need for multiple gear posture adjustments, significantly improving efficiency compared to traditional optical measurements. Furthermore, the spiral scanning path planning eliminates blind spots in areas such as the tooth root and tooth surface, allowing for simultaneous identification of surface wear and internal defects, meeting the high-precision, full-dimensional inspection requirements of aerospace gears. Simultaneously, by updating the standard parameter model, this method is adaptable to the inspection of different types of aerospace gears, such as helical and bevel gears, demonstrating excellent versatility. Detailed Implementation

[0012] Example 1: A laser holographic method for full-dimensional detection of aircraft gears, comprising the following steps: Step 1: Gear positioning and fixing: The aircraft gear to be tested is installed on an adjustable positioning platform. The gear is positioned by the center hole and limited in the circumferential direction to ensure that the rotation axis of the gear coincides with the reference axis of the positioning platform. Step 2: Scanning parameter adaptation: Based on the tooth profile and material properties of aircraft gears, the laser wavelength, emission power, and spot size of the laser holographic emission module are set; Step 3: Panoramic Scan Path Planning: The control and positioning platform drives the gear to rotate at a constant speed, and synchronously adjusts the spatial position of the laser emission module to form a spiral scanning path covering the gear tooth tip, tooth surface, tooth root and end face; Step 4: Holographic Signal Acquisition and Processing The laser holographic signal reflected from the gear surface is received in real time, and a three-dimensional holographic image of the gear is reconstructed through a phase demodulation algorithm to generate panoramic data containing the outer contour and internal structure of the gear. Step 5: Defect Identification and Result Output: By comparing panoramic data with a preset standard parameter model of aviation gears, defects such as tooth surface wear, tooth cracks and internal porosity are automatically identified, and an inspection report on the location and type of defects is output.

[0013] Example 2: According to the laser holographic full-dimensional detection method for aviation gears described in Example 1, the positioning platform in the first step of positioning and fixing is equipped with a coaxiality calibration component. By monitoring the radial runout during gear rotation in real time, the positioning fixture is dynamically adjusted to ensure gear rotation stability.

[0014] Example 3: According to the laser holographic all-dimensional detection method for aviation gears described in Embodiment 1 or 2, when planning the panoramic scanning path in step three, the moving speed of the laser emitting module is matched with the rotation speed of the gear to ensure the overlap rate of adjacent scanning trajectories and avoid scanning blind spots.

[0015] Example 4: According to the laser holographic full-dimensional detection method for aviation gears described in Example 1, 2 or 3, based on the holographic signal acquisition and processing in step four, an adaptive filtering algorithm is used to denoise the acquired laser holographic signal to improve the detail clarity of the three-dimensional holographic image.

[0016] Example 5: According to the laser holographic full-dimensional inspection method for aircraft gears described in Examples 1, 2, 3, or 4, the standard parameter model preset in step 5 for defect identification and result output can be updated according to the design requirements of different types of aircraft gears to adapt to the inspection needs of multiple specifications of gears.

[0017] Example 6: According to the laser holographic full-dimensional detection method for aviation gears described in Embodiment 1, 2, 3, 4, or 5, the tooth type of the aviation gear in the step two scanning parameter adaptation is spur, helical, or bevel.

[0018] Preliminary preparation and parameter setting The aircraft gear to be tested is a spur gear for a certain type of engine transmission, with a standard involute tooth profile and made of high-strength alloy steel. The following preparations must be completed before implementation: Fixed positioning: Install the gear in the center fixture of the positioning platform, activate the coaxiality calibration component, monitor the radial runout of the gear during rotation, and control the runout within the preset range through fine adjustment of the fixture to ensure the stability of the gear rotation axis; Parameter adaptation: Based on the characteristics of alloy steel, the laser wavelength of the laser holographic emission module is set to the visible light band, the emission power is adjusted to a range that can produce clear images without damaging the gear surface, and the spot size is adapted to the gear tooth width to ensure that a single scan can cover the width of a single tooth surface.

[0019] Implementation of the testing process: The steps described above are for performing the detection: Scan path planning: The positioning platform drives the gear to rotate at a constant speed, while the laser emission module is controlled to move slowly along the gear axis, forming a spiral scanning trajectory. The moving speed and gear rotation speed are adjusted to ensure that the overlap rate of adjacent scanning trajectories meets the requirements, ensuring that there are no blind spots on the tooth surface. Signal acquisition and processing: While the laser emitting module scans along the planned path, it simultaneously receives the holographic signal reflected from the gear surface. An adaptive filtering algorithm is used to filter out ambient light interference, and then a phase demodulation algorithm is used to process the signal to reconstruct a three-dimensional holographic image containing the gear tooth tip, tooth surface, tooth root, and internal structure, generating panoramic data. Defect identification and report output: The system calls upon a preset standard parameter model for this gear model and compares the panoramic data with the standard model. If the detection reveals a difference between the grayscale value of the holographic image of a certain gear tooth root region and the standard model, further analysis confirms that the region is an internal microcrack. The system automatically marks the circumferential and axial positions of the crack and generates a detection report containing the defect image, location coordinates, and type.

[0020] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A laser holographic method for full-dimensional detection of aircraft gears, characterized in that, The method includes the following steps: Step 1: Gear positioning and fixing: The aircraft gear to be tested is installed on an adjustable positioning platform. The gear is positioned by the center hole and limited in the circumferential direction to ensure that the gear's rotation axis coincides with the reference axis of the positioning platform. Step 2: Scanning parameter adaptation: Based on the tooth profile and material properties of aircraft gears, the laser wavelength, emission power, and spot size of the laser holographic emission module are set; Step 3: Panoramic Scan Path Planning: The control and positioning platform drives the gear to rotate at a constant speed, and synchronously adjusts the spatial position of the laser emission module to form a spiral scanning path covering the gear tooth tip, tooth surface, tooth root and end face; Step 4: Holographic Signal Acquisition and Processing The laser holographic signal reflected from the gear surface is received in real time, and a three-dimensional holographic image of the gear is reconstructed through a phase demodulation algorithm to generate panoramic data containing the outer contour and internal structure of the gear. Step 5: Defect Identification and Result Output: By comparing panoramic data with a preset standard parameter model of aviation gears, defects such as tooth surface wear, tooth cracks and internal porosity are automatically identified, and an inspection report on the location and type of defects is output.

2. The laser holographic method for full-dimensional detection of aircraft gears according to claim 1, characterized in that, According to the steps described above, the positioning platform is equipped with a coaxiality calibration component. By monitoring the radial runout during gear rotation in real time, the positioning fixture is dynamically adjusted to ensure gear rotation stability.

3. The laser holographic method for full-dimensional detection of aerospace gears according to claim 1, characterized in that, In step three, during the panoramic scanning path planning, the moving speed of the laser emission module is matched with the rotation speed of the gear to ensure the overlap rate of adjacent scanning trajectories and avoid scanning blind spots.

4. The laser holographic method for full-dimensional detection of aircraft gears according to claim 1, characterized in that, Based on the holographic signal acquisition and processing in step four, an adaptive filtering algorithm is used to denoise the acquired laser holographic signal, thereby improving the detail clarity of the three-dimensional holographic image.

5. The laser holographic method for full-dimensional detection of aerospace gears according to claim 1, characterized in that, The standard parameter model preset in step five for defect identification and result output can be updated according to the design requirements of different types of aircraft gears to adapt to the inspection needs of multiple specifications of gears.

6. The laser holographic method for full-dimensional detection of aircraft gears according to claim 1, characterized in that, According to the scanning parameters in step two, the tooth type of the aircraft gear is spur, helical, or bevel.