Unlock instant, AI-driven research and patent intelligence for your innovation.

LED free-form surface array design method based on leather surface defect detection

A technology for LED arrays and defect detection, applied in design optimization/simulation, calculation, special data processing applications, etc., can solve problems such as poor stability and increased computing time

Active Publication Date: 2019-02-15
JIANGNAN UNIV
View PDF2 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The existing solution is to make the image obtained by uneven illumination meet the detection requirements through image processing, but image processing will not only increase the calculation time, but also have poor stability

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • LED free-form surface array design method based on leather surface defect detection
  • LED free-form surface array design method based on leather surface defect detection
  • LED free-form surface array design method based on leather surface defect detection

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0061] 1. Derivation of the theoretical model of off-axis illumination distribution of LED array

[0062] figure 1 It is a schematic diagram of the coaxial illumination of the LED, the LED is located at point A (X, Y, Z), and AB is the vertical distance from the target surface, and the angle between the optical axis and the normal of the target surface is α. When α=0, it is coaxial irradiation, that is figure 1 , then the illuminance at any point D(x,y,0) on the target surface I is

[0063]

[0064] I in formula (1) 0 is the light intensity of LED, m=-ln2 / ln(cosθ 12 ), θ 12 is the LED half-angle width, Then formula (1) can be rewritten as:

[0065]

[0066] When α≠0, that is figure 2 , then there is Equation (2) still applies. Then the off-axis illuminance distribution of LED on surface II can be expressed as:

[0067]

[0068] Considering that LED is a non-correlated light source and the superposition principle of light, if the spatial distribution has...

Embodiment 2

[0090] Application of LED array device designed according to embodiment 1 in machine vision leather defect detection: as Figure 9 As shown, the machine vision leather defect measurement system, the image acquisition system is Mercury MER-200CCD, and the Laws texture filter is used to extract texture features through programming on the Halcon platform, and the Gaussian mixture model classifier is used for defect detection. The test sample is monochrome textured leather with surface printing and dyeing defects provided by Benecke Changshun Company. For comparative analysis, two LTH-300 strip light sources were also selected. Two light sources and four lighting methods were used for detection, see Table 1. In Table 1 (a) and (b) are the direct type and double-sided symmetrical lighting methods, respectively, and the dark grain defects on the leather surface cannot be identified; (c) the single-side illumination of the plane light source composed of double strip light sources ca...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses an LED free-form surface array design method based on leather surface defect detection, belonging to the field of machine vision detection LED lighting. A theoretical model ofoff-axis illumination distribution on LED free-form surface is constructed. The particle swarm optimization algorithm based on simulated annealing and the constraint conditions are introduced to construct the uniformity evaluation function, and the optimal solution of LED free-form surface array which can realize off-axis uniform lighting is obtained by optimization simulation. The LED array provided by the invention can realize uniform illumination through physical test, and the illumination uniformity reaches 91.86%. The LED array provided by the invention can be applied to machine vision leather defect detection, and can realize precise detection of defects such as scratches, breakages, stains, impressions and the like existing on the leather surface.

Description

technical field [0001] The invention relates to an LED free-form surface array design method based on leather surface defect detection, and belongs to the field of machine vision detection of LED lighting. Background technique [0002] Artificial leather has been widely used in our life due to its low price and rich colors. People have higher and higher quality requirements for leather products. Some defects must be detected, and some printing and dyeing defects such as uneven colors that can only be seen at certain angles or special lighting cannot be ignored. In order to improve production efficiency and product quality stability, machine vision inspection has become a development trend. Illumination sources are an important part of machine vision systems. The choice of light source will affect the imaging quality, and then affect the performance of the whole system. The role of the light source is to obtain a contrasting image, increase the gray value difference betwee...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): G06F17/50
CPCG06F30/20
Inventor 高淑梅王德宇钱维莹曹建军杨国锋
Owner JIANGNAN UNIV
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com