Thread Characteristic Detection Using Analog-Digital Sensor Calibration
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Solution Overview
Problem
Existing methods for detecting thread characteristics in textile or metal threads fed to operating machines face challenges in accuracy and cost, particularly with analog sensors' variability and digital sensors' complexity, and require multiple light sources or coherent light, making them unsuitable for real-time, low-cost monitoring in textile machines.
Innovation Solution
A system combining an analog photodiode with a CMOS or CCD digital sensor, using a single light source and ambient light, where the digital sensor spatially digitizes the thread shadow and calibrates the analog sensor's measurements in real-time, enabling accurate and instantaneous detection of thread characteristics like diameter and fineness without infrared radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If analog sensors (photodiode) are used to detect thread characteristics, then the device complexity and cost are low, but the measurement precision and reliability are insufficient due to variability
Solution Approach 1:
The sensor is segmented into two independent detection parts: an analog photodiode for fast response and a digital sensor (CCD/CMOS) for high precision. Each part processes different aspects of the thread shadow, allowing the system to combine speed and accuracy without using a single complex sensor
Solution Approach 2:
The system changes the detection parameter by using two different sensor types with different characteristics. The analog photodiode provides rapid temporal response while the digital sensor provides spatial resolution. By processing signals from both sensors and combining them, the system achieves both fast response and high measurement precision
2Measurement precision
If digital sensors (CCD/CMOS) are used to detect thread characteristics, then the measurement precision is high, but the device complexity and cost increase
Solution Approach 1:
The patent merges analog and digital sensor technologies into a single integrated sensor device. The analog photodiode and digital sensor (CCD/CMOS) are positioned adjacent to each other within the same sensor housing, sharing common optical elements and processing circuitry. This combination allows the system to achieve high measurement precision through the digital sensor while maintaining relatively simple device structure through the analog component's simplicity
3Measurement precision
If multiple light sources or coherent light are used to illuminate the thread, then the measurement accuracy is improved, but the device complexity and cost increase
Solution Approach 1:
The single light source serves multiple functions: it illuminates the thread for both analog and digital sensor detection, provides sufficient intensity for accurate shadow formation, and eliminates the need for complex multi-source illumination systems. The light source is designed to work effectively with both sensor types simultaneously, achieving universal functionality with a single component
4Productivity
If the sensor responds slowly to thread characteristic changes, then the processing complexity is reduced, but the productivity and real-time monitoring capability are insufficient
Solution Approach 1:
The system dynamically adapts to different thread speeds and monitoring requirements by combining fast analog response with precise digital measurement. The analog photodiode provides immediate response to rapid changes in thread characteristics, while the digital sensor captures detailed spatial information. This dynamic combination allows real-time monitoring at high speeds without sacrificing measurement accuracy or requiring overly complex processing
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for quick, accurate, and cost-effective monitoring of thread characteristics, including diameter, fineness, and feed rate, in real-time, even with multiple threads, using compact and low-cost electronics, independent of machine speed and ambient light variations.
Implementation Method 1
light emission generated from an illuminating device, such as an LED
Implementation Method 2
the shadow generated by the thread on the detector part of such a sensor after the thread has been 'struck' by light emission
Implementation Method 3
Analog sensors usually comprise a photodiode onto which the shadow of the thread struck by the light generated by a LED is formed
Data Source
Figure 1~2
Figure 3~4
AI summary
A method for detecting a characteristic of a textile or metal thread (F) fed to an operating machine (M), said method comprising the generation of a light signal impacting the thread which creates a shadow on an optical sensor device connected to means (8) for monitoring a characteristic of the thread on the basis of an electrical signal emitted by such sensor device as a function of the shadow generated on said sensor device by the thread (F) itself, said characteristic being a physical characteristic of the thread such as its diameter or a characteristic of the feed of the thread when in movement, such as its speed. It is provided that the signal detected by said sensor device (2) comprises a signal detected in analog mode and a signal detected in digital mode, the signal detected in digital mode providing real time calibration of the signal detected in analog mode so as to generate an electrical signal used by the monitoring means (8) to monitor the characteristics of the thread. The system operating according to this method is also claimed.