DESIGN AND TESTING OF AN AUTOMATIC SEEDLING-LOADING SYSTEM FOR A HIGH-SPEED RIDE-ON RICE TRANSPLANTER

Abstract

Seedling replenishment during the operation of high-speed ride-on rice transplanters still relies heavily on manual labor, thereby limiting the level of operational automation. To address this limitation, an automatic seedling-loading system comprising a longitudinal conveying mechanism, a lateral drive mechanism, and a tracking compensation mechanism was developed. Based on an STM32 embedded platform, a control strategy for detecting seedling shortages and performing precise seedling-loading operations was developed, enabling automatic shortage detection, lateral positioning, and targeted seedling replenishment. The main operating parameters—conveyor belt speed, lateral offset distance, and fore-aft tilt angle—were first investigated individually to determine their appropriate ranges. Subsequently, a second-order, three-factor, five-level rotatable orthogonal experiment was conducted. Seedling-loading success rate was used as the evaluation index, and a multifactor regression model was established to analyze the interactions among the factors. Bench tests were conducted to optimize the system parameters and determine the optimal parameter combination. Subsequent field trials confirmed the operational reliability of the system, with an average seedling-loading success rate of 90.67% over five batches of tests. The proposed system shows considerable potential for replacing manual loading of mat-type rice seedlings and provides a practical solution for advancing the full-process automation of rice transplanting operations.