基于线激光与LED的棉花中异性纤维检测方法  

Detection method of foreign fibers in cotton based on illumination of linelaser and LED

作　　者：张林[1] 韦平[1] 伍剑波[1] 刘翔[1] 苏真伟[1,2] 

机构地区：[1]四川大学制造科学与工程学院,成都610065 [2]广东理工学院,肇庆526100

出　　处：《农业工程学报》2016年第15期289-293,共5页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(31371536)

摘　　要：激光成像可以检测出皮棉中的白色异性纤维,而深色和有色的异性纤维反光性能差,激光成像难以检测。该文提出了一种基于LED与线激光的双光源一次成像方法,可以检测出各种颜色的异性纤维。试验以白色、深色和浅色共20种典型异性纤维和皮棉作为样本,在相机曝光时间与光圈不变的条件下,逐步改变LED亮度和线激光功率,发现在RGB颜色空间,利用R(红色)通道,白色异性纤维与棉花的可分度随着激光功率的增大而增大,达到峰值之后又逐步减小;在HIS颜色空间,利用S(饱和度)通道,有色异性纤维与棉花的可分度随着LED亮度的增大而增大,达到峰值之后又逐步减小。在此基础上,该文获取了310幅棉花与异性纤维的图像,作出了基于R与S通道的图像可分度、LED亮度与激光功率的对应变化曲线,然后将两种曲线进行融合,在曝光时间106μs、光圈2.8C条件下,发现线激光功率7.01 m W、LED亮度3 326 lx时,白色异性纤维和深色、有色异性纤维与棉花的可分度最大。采用上述双光源成像参数和该文的成像装置获取840幅图像,通过简单的二值化图像分割算法,白色异性纤维的正确识别为84.1%,深色和有色异性纤维正确识别为93.9%,优于单独激光成像或单独LED成像的识别率。It is difficult for the existing machine vision systems to sort out white foreign fibers （contaminants） from cotton because their colors are the same or very close. The laser imaging method previously suggested by our research team can detect most of the white foreign fibers in cotton, but the reflect lights of laser from most of the colored foreign fibers, especially from the ones with deep colors are so weak that the colored foreign fibers cannot be distinguished from cotton. In this paper, a new method using a double-light illumination of light emitting diode （LED） and laser for imaging was presented, which could detect different colored foreign fibers, including most of the foreign fibers with white color and deep colors. In the experiment, lint cotton and 20 kinds of typical foreign fibers with deep colors, light colors and white color were collected from a textile plant, and then the foreign fibers were randomly distributed on the cotton surface and driven by a conveyor. Using the line-laser at wavelength of 658 nm, exposure time of 106μs and aperture of 2.8 C that were previously suggested by our team, 310 frames of the sample images were obtained by a high-speed color line-scan camera under the double-light illumination formed by 2 LED arrays with adjustable luminance and a line-laser with adjustable power. Then, the quantized differences of foreign fibers and cotton background in each frame of the image were calculated by their average pixel values in R channel of RGB （red, green and blue） color space and their average saturation values in S channel of HIS （hue, saturation and intensity） color space separately. Based on the experiment, it was found that in the R channel or S channel, with the increase of the line-laser power or the LED luminance, quantized differences of the foreign fibers and cotton were enlarged, and after the differences reached the maximum value, the curve gradually decreased from the top. Thus, by the significant difference of the targets and background at the 2 cur

关 键 词：棉花 激光 发光二极管 彩色异性纤维 双光源 机器视觉 

分 类 号：S24[农业科学—农业电气化与自动化] TP391.41[农业科学—农业工程]