Development and Optimization of End-Effector for Extraction of Potted Anthurium Seedlings during Transplanting

Conventional transplanting of potted seedling, which is an essential operation for seedling growth, is still performed manually. We have developed an end-effector for automated transplanting of potted in greenhouses. The end-effector extracted seedlings through three phases: gathering, grasping, and stabilizing. This operation allowed a grasp of the seedling from both sides, protected the leaves with gathering plate, and guaranteed the stability of the seedling with steel needles. Furthermore, this study aimed at optimizing the operation parameters of transplanting end-effector with the focus on the extracting effect. Three variables, extracting pressure, insert distance of steel needle, and insert angle of steel needle, were optimized by analyzing the operation process of the transplanting end-effector. The comprehensive weighted scoring method was used to evaluate the extracting effect of transplant end-effector. The optimal operation parameters of the transplant end-effector were obtained by using the quadratic regression orthogonal rotation combination design. The quadratic regression equation was fitted to correlate the extracting performance. It was found that the insert distance of steel needle was the most significant parameter affecting the extracting effect. Finally, using desirability function method, the optimal parameters for maximizing weighted value of extracting effect were determined. The optimal combination of operation parameters was extracting cylinder pressure=0.36 MPa, insertion angle of steel needle = 28°, and, the insert distance of steel needle = 38mm, which achieved the maximum weighted value of extracting effect of 93.94. The performance of optimized transplanting end-effector was examined by confirmation test. The test result proved that it could finish the task of seedling extraction with excellent performance, and archive 100% success rate with 1-s single operation cycle.