Weld Signature Shape Analysis for Short-Duration Quality Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for determining weld quality, particularly for short-duration welds, are inaccurate due to the instability of welding parameters, which may never reach a steady state, leading to unreliable automated characterization.

Innovation Solution

A signature shape-based approach is employed, where the computing device captures and compares the shape of weld signatures to reference signatures, determining weld quality by analyzing shape differences and boundaries, allowing for accurate assessment regardless of parameter stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If parameter value-based weld quality determination is used, then weld quality can be assessed by comparing parameters to acceptable levels, but the method becomes inaccurate for short-duration welds where parameters never reach steady state

Engineering Contradiction:
Improveweld quality determination accuracyVSAvoidapplicability to short-duration welds
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent transitions from analyzing parameter values to analyzing the shape characteristics of welding parameters. By examining features such as peaks, valleys, slopes, and curvature of voltage and current waveforms, the system can accurately assess weld quality without requiring parameters to reach steady state, thus resolving the contradiction between measurement precision and adaptability to short-duration welds.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If multiple weld parameters are monitored and multiple quality parameters are calculated to generate an overall weld score, then comprehensive weld quality assessment is achieved, but the complexity of the determination system increases

Engineering Contradiction:
Improveoverall weld quality assessmentVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and focuses on the essential shape characteristics of welding parameters (peaks, valleys, slopes, curvature) rather than processing multiple complex quality parameters. This extraction of key shape features maintains reliable weld quality assessment while significantly reducing system complexity compared to multi-parameter calculation approaches.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3542943B1Method of and non transitory computer readable storage medium for determining weld quality by realising a weld signature analysis
Publication Date: 2023.04.26 LINCOLN GLOBAL INC
  • EP3542943B1 patent drawingFigure 1
  • EP3542943B1 patent drawingFigure 2~3
  • EP3542943B1 patent drawingFigure 4

AI summary

A method of determining weld quality includes the step of providing a reference weld signature having a first shape. A weld signature (200) of a welding parameter is captured, wherein the weld signature (200) of the welding parameter has a second shape. The first shape is automatically compared to the second shape and a weld signature shape difference between the first shape and the second shape is determined. A weld fault condition is determined based on the weld signature shape difference.