Measuring yarn diameter using inexpensive optical sensors

A comparative study between yarn diameter and yarn mass variation measurement systems using capacitive and optical sensors

This paper reports a comparative study between yarn mass and yarn diameter measurement systems using a differential capacitance tester and an optical coherent signal processing diameter tester respectively. A full description of the systems is presented along with their new contributions, namely 1mm length samples analysis for a capacitive tester and optical signal processing to eliminate the i...

Short-Term Motion Tracking Using Inexpensive Sensors

Identification of Yarn Periodical Errors Using Signal Processing Techniques Based on Capacitive and Optical Sensors Measurements

This paper presents a study to identify the type and location of yarn periodical errors applying three different signal processing approaches based on FFT – Fast Fourier Transform, FWHT-Fast Walsh-Hadamard Transform and FDFI – Fast Impulse Frequency Determination. The errors determination is applied for the mass measurement of yarn using a capacitive sensor and for the measurement of yarn diame...

Improving the Accuracy of Inexpensive Sensors for Optical Density Measurement

A common problem in the field of color printing is closed loop color calibration, a process which generally requires a spectrometer. Light Emitting Diodes (LED) sensors are inexpensive and effective for measuring the net reflectance of certain frequencies of light. Sensor measurement of LED reflectance can be used to estimate spectral reflectance or color value (measured in CIELAB or CIEXYZ col...

Carbon nanotube yarn strain sensors.

Carbon nanotube (CNT) based sensors are often fabricated by dispersing CNTs into different types of polymer. In this paper, a prototype carbon nanotube (CNT) yarn strain sensor with excellent repeatability and stability for in situ structural health monitoring was developed. The CNT yarn was spun directly from CNT arrays, and its electrical resistance increased linearly with tensile strain, mak...