Design Method of Fabric Density Sensor Based on the Virtual Grating With Gradual Constant

In order to overcome the shortcomings of time-consuming and inefficient manual detection methods of fabric density, a fast and efficient automatic detection method of fabric density based on the digital grating is proposed. In order to realize automatic fabric density detection, the design method of the digital grating with gradual constant is described in detail on the basis of the principle of moiré pattern. The moiré pattern containing yarn density information of the fabric can be obtained by superimposing the captured fabric image and the digital grating image. After the moiré pattern is projected, the fabric density can be accurately determined by analyzing the distribution characteristics of projection curve. In the detection process, a digital grating image generated by computer is used to replace the physical grating, which not only makes the detection faster, but also make the system applicable for the fabric density detection of all kinds of specifications. Testing experiments were carried out on various fabric samples including fabrics in a plain weave and in a twill weave, the detection accuracy is more than 99.2% and the detection speed is much faster than the existing methods, which can meet the requirements of on-line detection in fabric production.