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DEVELOPMENT AND EXPERIMENT ON AUTOMATIC GRADING EQUIPMENT FOR KIWI
Authors: Xu L., You Z., Wu S., Zhao H., Wu L.
Number of views: 345
There is little equipment specially developed for
grading kiwi fruit in both China and foreign countries. While the full automatic grading equipment often has complex mechanical structure and costs highly, it always grades kiwi fruit on the basis of singular feature such as size, weight, shape, color and surface defect such that it is hard for them to promote kiwi fruit’s market competitiveness. Therefore, this paper developed a set of practical automatic kiwi fruit grading equipment basing on technologies of mechanical separation and conveyance, image capture and processing as well as intelligent control. This set of equipment mainly consists of
material storage bin, single-line positioning system, image capture system and grading executive system. And it also has programs of image capture, image processing, grade determination and human-machine interaction for the host computer as well as control programs for the slave computer.
Its operating principle is that: firstly put a small amount of kiwi fruits or slowly put kiwi fruits into the storage bin and switch on, and then the host computer sends the startup command to the slave computer. Upon receiving such command, the slave computer starts grading equipment and initializes the camera. The camera will then get into the image capture state. Kiwi fruits are conveyed to the image capture system by the single-line positioning system in single row. Upon the slave computer receives the signal that kiwi-fruits are on position sent by the position sensor of the image capture system, it will immediately send such signal to the host computer. Then the host computer will store the images from the camera at this time and discard the images captured at other time. After the host computer carries out
relevant operations such as image processing and grade
determination to moving images, it will send grading results to the slave computer. At this time, the kiwi fruits will have been
conveyed to the grading implementation area and the slave
computer will control the implementation system at all levels
to perform grading. Each kiwi fruit will be graded through the same grading flow. By testing, this equipment is capable of grading by three features of size, shape and surface defect and their grading accuracy can reach to 88.9%, 91% and 94% respectively. And the accuracy of integrated grading can reach to 86%. The output of this equipment can reach to 1.22kg/min which is much more than the efficiency of manual grading. With simple mechanical structure and low cost, this equipment reduces the processing cost of kiwi fruit and is suitable to vast middle and small users.