基于机器视觉定位的家禽屠宰净膛系统设计与试验

针对国内家禽屠宰净膛作业中存在的劳动强度大、工作效率低、作业环境差等问题,设计了一种基于机器视觉定位的家禽屠宰净膛机械手系统。系统由家禽胴体悬挂输送装置、双直角坐标式机械手本体、机器视觉系统和PLC控制系统组成。通过视觉系统在线采集家禽胴体和膛口图像,采用中值滤波和灰度增强对胴体图像进行预处理,然后用全固定阈值法进行图像的二值化,设定面积阈值后通过闭运算以及孔洞填充得到分割掉家禽翅膀和腿部的二值图像,计算二值图像轮廓,获取质心坐标;采用最大内接圆法对家禽膛口进行定位,得到膛口中心坐标;坐标变换后将数据传输到PLC控制器中,指导机械手完成净膛工作。试验结果表明,该系统对家禽外形轮廓质心坐标、膛口中心坐标的重复定位精度分别达到±1.6、±1.52像素,净膛机械手能够准确抓取内脏,内脏平均残留率为7.63%,内脏平均破损率为23%。

Design and Experiment of Poultry Eviscerator System Based on Machine Vision Positioning

Aiming at the problems of labor intensity, low efficiency and poor working environment, a system of poultry slaughtering robot based on machine vision was designed. The system consisted of four parts, which included a rectangular coordinate manipulator body, poultry carcass suspension conveyor, PLC control system and machine vision system. Collecting poultry carcass and poultry muzzle images online through the visual system, the carcass image was pretreated by median filter and grayscale enhancement, and then the image was binarized by using the total fixed threshold, after setting the area threshold and obtaining the binary image which cut off the poultry wings and legs through the closed operation and hole filling. Finally, the binary image contour was calculated, the center of mass coordinates was got. In order to obtain the coordinates of center of muzzle, the poultry muzzle was positioned by the maximum internal circle method. The center of the maximum internal circle was the center of muzzle. Combining the coordinates of the center of mass with the coordinates of the center of muzzle, and then converting the coordinates information to digital information, the data of digital information would be transmitted to the PLC controller, to guide the manipulator to complete the work of the evisceration. The results of the experiment showed that the accuracy of the coordinates of poultry profile contour centroid and muzzle center was ±1.6 pixel and ±1.52 pixel. The eviscerating manipulator can accurately grasp the internal organs, the residual viscus in the body was 7.63%, and the breaking rate was 23%.