Design and Experiment of an Integrated Automatic Transplanting Mechanism for Picking and Planting Pepper Hole Tray Seedlings

The operation of the semi-automatic pepper pot seedling transplanter has the problem of a low frequency of manual operation. We designed a new automatic transplanting mechanism based on a clamping stem. Through the movement law of a double-crank connecting rod mechanism, the static trajectory of beak shape and the dynamic trajectory of N shape were designed to meet the requirements of backward transplanting. The kinematics equation of the seedling picking mechanism was established and the mechanism parameter optimization program was developed based on MATLAB. The effect of the mechanism parameter changes on the seedling movement trajectory was analyzed. A group of parameter combinations that met the requirements of seedling picking and planting were optimized. After optimization, the trajectory height was 220.8 mm, the picking angle was 21.03° and the planting angle was 64.15°. The plant spacing was 260 mm, which meets the agronomic requirements of pepper transplanting. Through the combination of theoretical analysis and prototype tests, the test results showed that the theoretical trajectory was basically consistent with the actual trajectory, verifying the feasibility of the mechanism design. In this study, pepper pot seedlings in the suitable planting period of 60 days were selected and planted at the rotation speed of 60, 70 and 80 r/min, respectively. The success rate of seedling selection was more than 91.1%, the success rate of planting was more than 78.5%, the qualified rate of erect degree was 94.9%, and the coefficient of variation of plant spacing was stable below 14.1%. The results show that the integrated automatic transplanting mechanism for pepper pot seedlings was effective.