Research And Design Of Key Technologies For Automatic Leaf Sorting

At present, before the cigarette products are sold to customers, the tobacco should be baked and classified, and then sent to the factory for further processing. With the growing increase of labor cost, the uncertainty caused by manual classifying has lead to the increasing of labor, material and financial resources. Therefore, it will have important significance in reducing the cost of cigarette products, alleviating the contradiction between farmers and factories, and increasing the income of farmers to research and develop a tobacco leaf grading system based on computer intelligence. However, research interesting mainly focus on software development of tobacco classification based on computer vision rather than hardware development. Therefore, a hardware grading system of tobacco leave based on computer vision was designed and the key components of the system were determined in this paper. Simulation analysis to main parameters which affects the key components performance was carried out. With the experimental studymethod, the main influence factors and posture correcting method to tobacco leaves spreading were obtained, and the best parameter combinations were even got. In this paper, the main research contents and results are as follows:(1) The main procedure of tobacco leaf classification was designed, which included tobacco leaf posture correcting, tobacco leaf spreading, the image acquisition and recognition process of tobacco leaf, and tobacco leaf sorting process. First tobacco leaves were threw by manual on the conveyor belt, then the leaves went through the posture correcting process, so the tobacco leaves on the transmission belt were able to go though tobacco leaf spreading mechanism with a desirable direction; After tobacco leaves went through spreading equipment and entered the image taken device, its grade was determined by a computer; Then the tobacco leaves went into the tobacco sorting process. Tobacco leaf whose grade had been determined in the tobacco sorting process was passed to the corresponding tobacco collection box.(2) The 3D models of the tobacco grade sorting device and leaf posture correcting device were designed. Tobacco spreading device was improved by using software NX Unigraphics. The structures and parameters of the key components such as the control system, the bracket of sorting device, tobacco leaf grading box, conveying system and executing system were determined. Meanwhile, the relevant hardware parts of tobacco leaf grading based on computer image recognition were designed.(3) The rolling brush and brush hair of tobacco leaf paving mechanism were simulated by using software RencurDyn. The best parameter combinations of tobacco spreading mechanism were obtained. The simulation results on the basis of the existing tobacco leaf paving mechanism were verified. Simulation results show that the best combination of brush rolls, speed difference of adjacent brush rollers, radius of brush roller, the length of brush hair, the length of brush hair, the brush materials, and center distance of adjacent brush roller is 5 logarithmic 20 r/min, 25 mm, the 35 mm, nylon 1010,and 100 mm respectively. The node strain of the brush roll is 0.1892 under such a combination. The spreading effect was tested by using the designed spreading device. The effect is best under such combination. The transverse diastolic rate of tobacco leaf is about 19%, and area change rate of the tobacco leaf is about 74.3%.(4) The 3D model of tobacco leaf posture correcting rack, tobacco paving device frame, tobacco sorting device rack in tobacco grading device by using software Unigraphics NX were designed. The mode analysis of frame of tobacco leaf posture correcting, tobacco leaf paving device and tobacco leaf sorting device were carried out by using software ANSYS Workbench. The result shows that when the frame walls thickness is 3mm, the first 4 natural frequencies of the tobacco sorting mechanism, the tobacco spreading mechanism, and the tobacco position correcting mechanism are mainly concentrated in the 55-161 HZ, 50.249-99.596 Hz, and 54.75-78 Hz respectively. When the frame walls thickness is 5mm, the frequencies of sorting mechanism frame, spreading mechanism, and position correcting mechanism are 66-114 Hz, 81.057-147.11 Hz, and74.796-103.52 Hz respectively. The result shows that the method is effective to improve the low order natural frequency of tobacco grading device by optimizing the frame walls thickness.