Development of a Circular Grafting Robotic System for Watermelon Seedlings

摘要

The aim of this research was to develop a top plug-in grafting robotic system that is applicable for grafting a scion into a mature rootstock before the scion's cotyledons spread. This would require the scion to be very delicate and greatly different from the rootstock in terms of seedling age. The grafting robotic system for watermelon seedlings consists of a rootstock processing unit and a scion processing unit, with dimensions of 120 cm 105 cm 130 cm. Both the rootstock and scion processing unit have a rotating disc, with the disc of the rootstock processing unit being lower than that of the scion processing unit; furthermore, the two discs rotate in opposite directions. A Geneva Wheel intermittent motion mechanism was adopted to drive the discs so that simultaneous and opposite movement was possible. The rootstock processing unit takes charge of removing the leaf bud from the rootstock seedling and drilling a hole for the scion, while the scion processing unit performs the action of cutting the scion seedling to make a sharp angle and finishes the grafting operation by inserting the scion into the hole in the rootstock. The developed grafting robotic system is characterized by the absence of grafting clips. This research employs bottle gourd Chiang-Li #1 as the rootstock and watermelon Fu-Bao #2 as the scion to conduct a series of mechanical grafting experiments. The experimental results showed that the grafting robotic system was able to accurately finish all grafting procedures and operations, with an average success rate of 95% and a working capability of 480 seedlings per hour. Demonstrations were held and farmers were highly satisfied with the system's functions and its performance.