Research On Detection Method Of High Precision Fabric Weft Oblique And Design Of Detecting Device

The fabric weft produced by loom is straight at the beginning. Once after hot dyeing and other special processing, the fabric weft skew or bend phenomenon occurs, due to the effects of heat and pull in the process, seriously affecting the level of textile and bringing huge losses to the textile enterprises. Under this background, all kinds of weft-straighteners arise at the historic moment. The weft-straightener generally consists of two parts:weft skew detection and weft skew correction. The performance of weft skew detection determines the quality of the entire weft-straightener, therefore, study of the weft skew detection methods and the corresponding detection devices design become more attention from the weft-straightener manufacturers.This paper puts forward two kinds of different weft skew detection methods and designs the corresponding weft skew detection device by combining the analysis of existing problems on recent weft-straightener with the characteristics of high-precision fabric texture. The first method for weft skew detection is based on the principle of photoelectric detection. To be specific, make the fabric wefts to be imaged onto the photoelectric sensors by using parallel light to illuminate them, and then quantitatively detect the weft skew angle through detecting the value of output signal of the photoelectric sensors. The second method for weft skew detection is based on machine vision. To be specific, using high-speed CCD camera extract frame image from fabric moving video sequence during production, and then display weft skew angle intuitively in real time calculated by the related image processing algorithms.The two kinds of automatic skew detection devices designed in this article have some performance improvement compared with the same type products, mainly in four aspects: First, photoelectric weft skew detection device achieves the function that the light source automatically adjusts the light intensity according to the thickness of the fabric, which not only makes the results more accurate, but also greatly improves the degree of automation of the equipment. Second, the anti-jamming capability of the system is enhanced a lot. In photoelectric weft skew detection device, the light source and its matched photoelectric sensors use the optoelectronic devices that its center wavelength is 850nm near infrared, while the installation of filters, effectively eliminating stray light. In the hardware circuit, power supply and other noise sensitive parts of the system have been done a filtering process, weakening the space electromagnetic interference. The anti-jamming ability of the system is greatly improved through these two aspects of processing. Third, simplify the circuit structure. Use discrete components to assemble circuits can greatly reduce system cost without affecting the function. Fourth, weft skew detection device based on machine vision uses a new detection algorithm, effectively reducing the space and time complexity of the system, accelerating the testing speed, improving the adaptability of system.Two weft skew detection methods and the corresponding detection devices presented in this paper have their advantages and disadvantages, but from the aspects of cost and environmental adaptability, photoelectric automatic weft skew detection device obviously has a broader application prospect.