Cloth Edge Detection Using Voltage Threshold Analysis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing cloth edge position detecting devices for sewing machines require complex configurations and detection processes due to the need for additional sensors to account for fluffs and notches, complicating the detection of cloth edges.

Innovation Solution

A simplified cloth edge position detecting device using a single cloth edge sensor and a control section that determines the cloth edge position based on voltage changes, distinguishing between fluffs, notches, and stepped portions without additional sensors, and adjusts the cloth edge position accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple sensors (cloth edge sensor, fluff sensor, notch sensor) are provided to detect different cloth conditions, then the detection accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvecloth edge position detection accuracyVSAvoidsensor configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The cloth edge sensor is designed to perform multiple functions: detecting cloth edges, fluffs, and notches all through a single sensor. The sensor outputs voltage signals that vary according to different cloth conditions, allowing one sensor to replace what would traditionally require multiple specialized sensors.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The sensor output voltage changes based on the cloth condition (edge, fluff, or notch). By monitoring voltage variations and their timing during cloth feeding, the system distinguishes between different cloth conditions without requiring additional sensors. The control section analyzes voltage change patterns to identify the specific cloth condition.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If multiple sensors are used to detect fluffs and notches separately, then the detection reliability is improved, but the detection processing complexity increases

Engineering Contradiction:
Improvecloth condition detection reliabilityVSAvoiddetection processing complexity
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The control section continuously monitors the voltage output from the cloth edge sensor and provides feedback to identify cloth conditions. By analyzing the timing and pattern of voltage changes during cloth feeding, the system reliably distinguishes between edges, fluffs, and notches through computational feedback processing.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary detection of cloth conditions by monitoring voltage changes as the cloth passes through the sensor. The control section identifies fluffs and notches before they affect sewing operations, allowing preventive measures to be taken. The voltage change patterns are analyzed in advance to determine cloth condition.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2581482B1Cloth edge position detecting device and sewing machine
Publication Date: 2015.09.16 JUKI CORP
  • EP2581482B1 patent drawingFigure 1
  • EP2581482B1 patent drawingFigure 2
  • EP2581482B1 patent drawingFigure 3

AI summary

The present invention relates to a cloth edge position detecting device and a sewing machine. The cloth edge position detecting device includes a cloth edge sensor (6) configured to output a voltage corresponding to a cloth edge position and a control section (71, 72) configured to detect the cloth edge position based on the voltage output from the cloth edge sensor (6). The control section (71, 72) determines that a position (Pos) at which a voltage change exceeding a cloth edge determining threshold (Ve) appears first in the direction from the inner side to the outer side of the workpiece cloth (W) across the cloth edge is the cloth edge position.