Adaptive Quality Thresholds for In-Process Machining Assessment

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Solution Overview

Problem

Existing quality assessment systems for machining processes, particularly welding, fail to automatically adjust quality criteria when machining parameters are consciously changed, leading to inaccurate quality judgments and potential rejection or acceptance of substandard workpieces.

Innovation Solution

The system automatically accounts for changes in machining parameters by adapting quality parameter limit values, ensuring that only intentional changes are considered, and uses real-time data or recorded changes to adjust quality assessments, thereby enhancing the reliability of quality monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If quality parameter limit values are fixed based on target machining parameters, then quality assessment is simple and consistent, but inaccurate when machining parameters are deliberately changed

Engineering Contradiction:
Improvequality assessment accuracyVSAvoidquality assessment system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The quality parameter limit values are made dynamic by automatically adapting them to the actual machining parameters used during processing. The system monitors changes in machining parameters and adjusts the corresponding quality limits in real-time, transforming the static quality assessment into a dynamic one that reflects actual processing conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements feedback by continuously monitoring machining parameters during processing and using this information to adjust quality parameter limit values. The actual machining parameters are fed back to the quality assessment module, which automatically adapts the quality criteria based on the observed parameter deviations.

Inventive Principle:
Principle #23Feedback

2Reliability

If quality criteria are manually adjusted when machining parameters change, then quality assessment remains accurate, but time consumption and operational complexity increase

Engineering Contradiction:
Improvequality assessment accuracyVSAvoidquality assessment operation ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The quality assessment system performs self-service by automatically detecting changes in machining parameters and adjusting quality parameter limit values without requiring manual intervention. The system autonomously monitors processing conditions and adapts quality criteria, eliminating the need for operators to manually adjust quality thresholds.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The manual mechanical adjustment of quality criteria is replaced by an automated electronic system that uses sensor data and computational algorithms to dynamically adjust quality parameter limits. This substitution of manual operations with automated electronic control improves both ease of operation and consistency.

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

3Productivity

If quality parameter limits are not adapted to machining parameter changes, then assessment process remains simple, but workpieces may be unjustifiably rejected or accepted

Engineering Contradiction:
Improvequality assessment efficiencyVSAvoidquality assessment accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary action by pre-establishing the relationship between machining parameters and quality parameter limit values. When machining parameters are set or changed, the corresponding quality limits are automatically prepared and adjusted in advance, enabling efficient real-time quality assessment without compromising accuracy.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4135924B1Method and device for assessing the quality of a processing process
Publication Date: 2024.06.19 FRONIUS INT GMBH
  • EP4135924B1 patent drawingFigure 1
  • EP4135924B1 patent drawingFigure 2A~2B
  • EP4135924B1 patent drawingFigure 2C~2D

AI summary

The invention relates to a method and a device (1) for assessing the quality of a processing operation, according to which method a workpiece (W) is processed with certain processing parameters (Pi(x)) along a processing trajectory (X), the processing result (R (x)) of the processing operation along the processing trajectory (X) is measured by means of at least one sensor (2) and at least one sensor signal (Sj (x)) is recorded and at least one quality parameter (Qk (x)) is determined on the basis of at least one sensor signal (Sj (x)) and the at least one quality parameter (Qk (x)) is compared with quality parameter threshold values (Qk,o (x), Qk,u (x)) in order to assess the quality of the processing result (R (x)) of the processing operation. According to the invention, any changes made to the processing parameters (ΔΡi(x)) with respect to the target values of the processing parameters (Pi, soll (x)) are automatically taken into consideration during processing, in that, instead of the quality parameter threshold values (Qk,o (x), Qk,u (x)), quality parameter threshold values Q'k,o(x), Q'k,u(x)) adapted to the changes of the processing parameters (ΔΡi(x)) are determined, and the at least one quality parameter (Qk (x)) is compared with the adapted quality parameter threshold values (Q'k,o(x), Q'k,u(x)) to assess the quality of the processing result (R (x)) of the processing operation along the processing trajectory (X).