Inclined Camera Yarn Detection for Weaving Shed Monitoring

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Solution Overview

Problem

Existing yarn detection systems for weaving machines fail to simultaneously capture the state of the shed of warp yarns and the travelling state of weft yarns due to the orientation of the camera, which either obscures the shed or weft yarn insertion direction.

Innovation Solution

A yarn detection system for weaving machines that includes a camera positioned upstream of the reed, inclined at an angle θc (0° < θc < 90°) to capture both the shed of warp yarns and the weft yarns, with specific positioning to ensure both the main nozzle tip and second sub-nozzle tip are within the camera's view during weft yarn travel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the camera captures an image from the front portion or upper portion of the loom frame to detect the travelling state of the weft yarn, then the travelling state of the weft yarn can be detected, but the state of the shed of the warp yarns cannot be detected

Engineering Contradiction:
Improvedetection of weft yarn travelling stateVSAvoidshed state information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The camera is positioned at an inclination angle θc (0° < θc < 90°) with respect to the right-left direction of the loom frame, capturing images from a diagonal dimension rather than from the front or upper portion only. This dimensional change enables the camera to simultaneously capture both the weft yarn travelling state and the shed state of the warp yarns by viewing the weaving process from an oblique angle that encompasses both spatial dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If the camera captures an image along the right-left direction of the loom frame to detect the state of the shed of the warp yarns, then the state of the shed can be detected, but the travelling state of the weft yarn cannot be detected

Engineering Contradiction:
Improvedetection of shed stateVSAvoidweft yarn travelling state information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The camera is positioned at an inclination angle θc (0° < θc < 90°) with respect to the right-left direction of the loom frame, capturing images from a diagonal dimension rather than from the front or upper portion only. This dimensional change enables the camera to simultaneously capture both the weft yarn travelling state and the shed state of the warp yarns by viewing the weaving process from an oblique angle that encompasses both spatial dimensions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If the camera is positioned to capture both the main nozzle tip and second sub-nozzle tip within the field of view, then both shed state and weft yarn travel can be detected, but the device complexity increases due to precise positioning requirements

Engineering Contradiction:
Improvesimultaneous detection of shed and weft yarnVSAvoidcamera positioning complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The camera is positioned at a specific inclination angle θc (0° < θc < 90°) with respect to the right-left direction of the loom frame, where θc satisfies the condition α - Φ ≤ θc ≤ β + Φ. By defining this angular parameter range based on the geometric relationships (α, β, Φ) between the camera position and the nozzle positions, the system transforms a complex positioning problem into a manageable parameter specification, simplifying installation while ensuring both the main nozzle tip and second sub-nozzle tip are captured within the field of view.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4692436A1Thread detection device for weaving machine
Publication Date: 2026.02.11 TOYOTA INDUSTRIES CORP
  • EP4692436A1 patent drawingFigure 1~2
  • EP4692436A1 patent drawingFigure 3~4
  • EP4692436A1 patent drawingFigure 5~6

AI summary

This thread detection device for a weaving machine is used in a weaving machine (10) provided with a weft insertion device (13) that has a main nozzle (14) which inserts a weft (Y) into a warp (T) opening in the left-right direction of a machine base (11), and a plurality of sub nozzles (15) which are arranged along the left-right direction of the machine base (11) and which discharge air with respect to the inserted weft (Y), and a reed (16) that beats the inclined weft (Y) by rocking in the front-rear direction of the machine base (11). The thread detection device for a weaving machine comprises a camera (32) that images an entrance (Tb) or an exit (Tc) of the opening from an imaging direction (C) such that an inclination angle (θc) with respect to the left-right direction of the machine base (1) is 0° &lt; θc &lt; 90°, and a thread detection unit that detects the warp (T) and the weft (Y) from an image captured by the camera (32).