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CN-121977473-A - Micro-morphology measurement and modeling method for light shield light blocking ring edge

CN121977473ACN 121977473 ACN121977473 ACN 121977473ACN-121977473-A

Abstract

The invention discloses a micro-morphology measuring and modeling method for a light shield light blocking ring cutting edge, and belongs to the technical field of precision measurement and three-dimensional modeling. The method comprises the steps of firstly obtaining three-dimensional point cloud data of a light blocking ring cutting edge through a laser scanning confocal microscope, carrying out denoising treatment on the data by adopting wavelet threshold denoising and five-point secondary smooth filtering, improving data precision by combining a clamp installation optimization and inclination correction technology, realizing data pruning through curvature analysis, extracting a cutting edge characteristic area, utilizing cubic B spline interpolation to repair missing data, and finally establishing a high-precision cutting edge model through trapezoid fitting, arc fitting and NURBS curved surface reconstruction methods. The invention solves the problem of insufficient accuracy of the micro-topography expression of the light-blocking ring edge of the light-blocking cover in the prior art, remarkably improves the accuracy and efficiency of the appearance characterization of the edge, and provides technical support for the surface topography design of the high-precision light-blocking cover.

Inventors

  • XUE YAOKE
  • WEI XINGUO
  • JIANG JIE

Assignees

  • 北京航空航天大学

Dates

Publication Date
20260505
Application Date
20260127

Claims (10)

  1. 1. The micro-morphology measuring and modeling method for the edge of the light blocking ring of the light shield is characterized by comprising the following steps of: The method comprises the following steps of (1) obliquely installing the cutting edge of a light blocking ring to be detected by using a clamp, adjusting the focal length of a microscope and the position of a workbench, and obtaining three-dimensional point cloud data comprising height, color and laser intensity; Step (2) carrying out wavelet threshold denoising and five-point secondary smoothing filtering treatment on the point cloud data; Step (3), calculating an inclination angle based on the multi-measuring-point height difference mean value, and eliminating installation inclination errors by using a reference point through a geometric compensation algorithm; Step (4) calculating the point cloud curvature by using a moving least square curved surface fitting, and trimming redundant data according to curvature mutation; step (5) adopting cubic B spline interpolation to repair point cloud data; And (6) constructing a three-dimensional model of the cutting edge through trapezoidal fitting, circular arc fitting and NURBS surface fitting.
  2. 2. The method for measuring and modeling the micro-topography of the cutting edge of the light shielding cover and the light shielding ring according to claim 1, wherein the inclination angle of the inclined installation in the step (1) is 15-45 degrees, double light sources are adopted for scanning, the double light sources are symmetrically arranged, and the incidence angle is 25-35 degrees.
  3. 3. The method for measuring and modeling the micro-morphology of the edge of the light shielding cover light shielding ring according to claim 1, wherein the wavelet threshold denoising in the step (2) adopts a Daubechies db6 wavelet basis function, the decomposition layer number is 5, and the threshold selection rule is a fixed threshold rule.
  4. 4. The method for measuring and modeling micro-topography of a light shield ring edge according to claim 1, wherein in the step (3), inclination angles are determined by calculating average values of height differences and horizontal distances of a plurality of groups of measuring points, and differential compensation is performed by using a base reference point.
  5. 5. The method for measuring and modeling micro-topography of a light shield and a light shield ring edge according to claim 1, wherein the reference point in the step (3) is selected by taking a right end point as a reference when the outline is tilted left and taking a left end point as a reference when the outline is tilted right.
  6. 6. The method for measuring and modeling the micro-morphology of the edge of the light shielding cover and the light shielding ring according to claim 1, wherein in the step (5), the cubic B spline interpolation is parameterized by an accumulated chord length method, and the control point is determined by a least square solution equation.
  7. 7. The method for measuring and modeling micro-morphology of the light shield and light ring cutting edge according to claim 1, wherein in the step (6), non-uniform rational B-splines are adopted for NURBS surface fitting, and three-dimensional morphology reconstruction is achieved through control points, node vectors and weight factors.
  8. 8. The measuring device for realizing the method of any one of claims 1-6 is characterized by comprising an adjustable inclination angle clamp (10) with an inclination angle adjusting range of 15-45 degrees, double light source modules (20) symmetrically arranged on two sides of a measured cutting edge and with an incidence angle of 25-35 degrees, and a laser scanning confocal microscope (30) for collecting height, color and laser intensity data.
  9. 9. A data processing system for executing any one of the methods 1-6 is characterized by comprising a denoising module, a correction module and a modeling module, wherein the denoising module is configured to perform wavelet threshold denoising and five-point secondary smoothing filtering, the correction module is configured to eliminate inclination errors based on a geometric compensation algorithm, and the modeling module is configured to select and output a trapezoid fitting model, an arc fitting model or a NURBS curved surface fitting model according to geometric features of a cutting edge area.
  10. 10. A terminal device, characterized in that the terminal device comprises a processor, a memory, a communication interface and a bus, the processor, the memory and the communication interface being connected via the bus and performing communication with each other, the memory storing executable program code, the processor running a program corresponding to the executable program code by reading the executable program code stored in the memory for performing the method according to any of the preceding claims 1-4.

Description

Micro-morphology measurement and modeling method for light shield light blocking ring edge Technical Field The invention belongs to the technical field of precision measurement and three-dimensional modeling, and particularly relates to a method for measuring and modeling micro-morphology of a light shield and a light blocking ring cutting edge, which is suitable for morphology analysis and quality control of high-precision elements in aerospace and optical instrument manufacturing. Background The shape of the edge of the light blocking ring of the light shield directly influences the stray light inhibition performance of the optical system. The traditional measuring method adopts a contact probe or a common optical microscope, and has the problems of low precision, easy damage to the surface, large noise interference and the like. In the prior art, although a laser scanning confocal microscope can acquire high-resolution data, measurement errors, noise interference and insufficient modeling precision of a complex curved surface caused by installation inclination still restrict the application of the confocal microscope. In addition, the data pruning and repair technology lacks pertinence, and it is difficult to accurately extract the cutting edge characteristic region. Disclosure of Invention The technical scheme adopted for solving the technical problems is that the micro-morphology measuring and modeling method for the cutting edge of the light blocking ring of the light shield is characterized by comprising the following steps: And (1) obliquely mounting the cutting edge of the light blocking ring to be detected by using a clamp, adjusting the focal length of the microscope and the position of a workbench, and obtaining three-dimensional point cloud data comprising the height, the color and the laser intensity. And (2) carrying out wavelet threshold denoising and five-point secondary smoothing filtering treatment on the point cloud data, removing noise and smoothing the data. And (3) calculating the inclination angle based on the multi-measuring-point height difference mean value, correcting the measured data by using a reference point through a geometric compensation algorithm, and eliminating the installation inclination error. And (4) calculating the point cloud curvature by using a moving least square curved surface fitting, judging the cutting edge area according to the curvature mutation, and trimming redundant data. And (5) repairing the point cloud data by adopting a cubic B spline interpolation method. And (6) constructing a three-dimensional model of the cutting edge through trapezoidal fitting, circular arc fitting and NURBS surface fitting. The invention also discloses a measuring device for the method, which is characterized by comprising an adjustable dip angle clamp (10) with a dip angle adjusting range of 15-45 degrees, double light source modules (20) symmetrically arranged at two sides of a measured cutting edge and with an incidence angle of 25-35 degrees, and a laser scanning confocal microscope (30) for collecting height, color and laser intensity data. The invention also discloses a data processing system for executing the method, which is characterized by comprising a denoising module, a correction module and a modeling module, wherein the denoising module is configured to execute wavelet threshold denoising and five-point secondary smoothing filtering, the correction module is configured to eliminate inclination errors based on a geometric compensation algorithm, and the modeling module is configured to output a trapezoid/circular arc/NURBS fitting model. The invention also discloses a terminal device which is characterized by comprising a processor, a memory, a communication interface and a bus, wherein the processor, the memory and the communication interface are connected through the bus and complete communication with each other, the memory stores executable program codes, and the processor runs a program corresponding to the executable program codes by reading the executable program codes stored in the memory so as to be used for executing the method. Advantageous effects (1) The invention adopts a clamp inclined installation mode. The clamp is obliquely arranged, so that different parts of the cutting edge can be exposed in a measurement view field at a more proper angle, and a measurement blind area caused by shielding of the structure of the workpiece is avoided. Meanwhile, the light source provides illumination for the cutting edge from different directions, so that the light reflection difference of the surface of the cutting edge is enhanced, and the measuring equipment can capture more fine morphological features. The unique measuring mode remarkably improves the integrity of the shape measurement of the cutting edge, can acquire detailed data of all corners and edges of the cutting edge, greatly improves the resolution, can clearly distinguish extremely tiny shape ch