Cigarette Defect Detection Using Variational Bayesian SSD

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Solution Overview

Problem

Existing cigarette manufacturing processes face challenges in accurately identifying appearance defects due to overconfidence decisions caused by point estimation in convolution layers and high computational complexity in two-stage target detection algorithms, leading to inefficiencies and resource wastage.

Innovation Solution

A method using variational Bayesian inference to improve the backbone network of SSD, replacing point estimation with probability distribution for convolution layer weights, enhancing feature extraction and detection accuracy while maintaining speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If point estimation mechanism is used in convolution layer, then computational efficiency is improved, but measurement precision deteriorates due to overconfidence decisions in data-scarce areas

Engineering Contradiction:
Improvecomputational efficiencyVSAvoiddefect detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent changes the parameter representation from point estimation to probability distribution. Specifically, it replaces the deterministic weight parameters in convolution layers with probabilistic parameters that capture uncertainty, allowing the model to express confidence levels and avoid overconfident decisions in data-scarce regions while maintaining computational tractability through variational inference

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent substitutes the classical point-estimation mechanism with a Bayesian probabilistic framework. This replacement introduces uncertainty quantification into the convolution layer, transforming the deterministic parameter update rule into a probabilistic inference process that can handle data scarcity without sacrificing computational efficiency

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If two-stage target detection algorithm is used, then measurement precision is improved, but device complexity increases with larger number of parameters

Engineering Contradiction:
Improvedefect detection accuracyVSAvoidnumber of parameters
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the target detection task into distinct stages (candidate generation and precise localization) while using probabilistic methods to reduce the overall parameter burden. The segmentation allows each stage to use optimized parameters appropriate to its function, reducing redundancy

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by using probabilistic approximation methods that compute only the necessary moments of the parameter distributions rather than full posterior distributions. This selective computation reduces the effective number of parameters that need to be stored and manipulated while maintaining detection precision

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If manual sampling inspection is used, then device complexity is reduced, but productivity deteriorates due to inability to achieve comprehensive quality monitoring

Engineering Contradiction:
Improveinspection system simplicityVSAvoidquality monitoring coverage
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent enables the inspection system to automatically perform comprehensive quality monitoring without human intervention. The probabilistic target detection model processes images autonomously, identifying defects and providing uncertainty estimates, thereby achieving both high productivity through comprehensive monitoring and reasonable complexity through automated algorithms

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS12633109B2Method for detecting cigarette appearance defect based on variational Bayesian inference
Publication Date: 2026.05.19 HONGYUN HONGHE TOBACCO (GRP) CO LTD
  • US12633109B2 patent drawing
  • US12633109B2 patent drawing

AI summary

The present application discloses a method for detecting cigarette appearance defects based on variational Bayesian inference. In a cigarette appearance defect detection scenario, in order to solve the problem that a current point estimation-based machine learning algorithm leads to an overconfidence decision in a data scarcity area, the present application proposes a variational inference-based Bayesian method to improve a SSD backbone network. The present application can improve the accuracy of defect detection without losing the processing speed, not only saving a large amount of manpower and material resources, but also effectively providing reliable technical support for finding the root causes of defect types. Thus, it achieves intelligent quality risk management and control in a cigarette production workshop.