Seam Profile Position Control Using Material Structure Comparison

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Solution Overview

Problem

Existing sewing technologies fail to achieve high accuracy in reproducibly positioning a seam course relative to structures on sewing materials, particularly with materials like leather that have inhomogeneous properties and complex patterns.

Innovation Solution

A method that adapts a sewing program by comparing reference structure data from a reference material to working structure data from the actual material being sewn, using a camera system to detect and adjust for deviations in position, size, and orientation, ensuring precise alignment and positioning of the seam course.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional sewing devices with basic camera detection are used, then the device complexity is low, but the manufacturing precision of seam position relative to material structure is insufficient

Engineering Contradiction:
Improveseam position precisionVSAvoidsystem complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by detecting and recording reference positions of material structures before sewing, generating reference structure data sets in advance. This allows the sewing program to be pre-adjusted based on detected deviations, ensuring high precision seam positioning without requiring complex real-time control systems during the actual sewing process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by creating digital representations (structure data sets) of the physical material structures. Reference structure data sets are generated from detected reference positions, and working structure data sets are created from detected working positions. These digital copies enable comparison and adjustment without directly manipulating the physical material, reducing device complexity while maintaining high precision.

Inventive Principle:
Principle #26Copying

2Manufacturing precision

If real-time adjustment of sewing program is implemented, then the manufacturing precision is improved, but the productivity decreases due to additional processing time

Engineering Contradiction:
Improveseam position precisionVSAvoidsewing speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The system performs detection and adjustment operations before the actual sewing process. Reference positions are detected and reference structure data sets are generated in advance, allowing the sewing program to be prepared with appropriate adjustments before production begins, thus maintaining high speed during actual sewing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback by comparing working structure data sets with reference structure data sets and using the detected deviations to adjust the sewing program. This closed-loop feedback ensures high precision while the adjustment process is efficiently integrated into the workflow, minimizing impact on overall productivity.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If detailed detection of material structures is performed, then the manufacturing precision is improved, but the measurement precision requirements increase

Engineering Contradiction:
Improveseam position precisionVSAvoidstructure detection precision
Core Design Contradiction:
Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary approach by using detected structure positions as reference points rather than requiring direct measurement of all material properties. The camera system detects key structural features (holes, patterns), and these detections serve as intermediaries to guide seam positioning, reducing the overall measurement precision requirements while maintaining high seam position precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

By creating digital copies (structure data sets) of the material structures, the system enables repeated analysis and comparison without requiring repeated high-precision measurements of the physical material. The digital representations can be processed multiple times with standard precision, achieving high manufacturing precision through computational rather than purely measurement-based approaches.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP3794173B1Method for controlling the position of a seam profile relative to structures of a sewing material
Publication Date: 2023.06.07 PFAFF INDUSTRIESYSTEME & MASCH GMBH
  • EP3794173B1 patent drawingFigure 1~2
  • EP3794173B1 patent drawingFigure 3
  • EP3794173B1 patent drawingFigure 4

AI summary

The present invention relates to a method for controlling the position of a seam profile and to a device for carrying out the method, wherein the position control of a seam profile relative to structures of a sewing material is based on comparison data of a structure of a reference sewing material and a structure of a working sewing material.