Design and Evaluation of a Dual-Chamber Pre-Cut Cassava Stem Filling Mechanism for Precision Planting

To address the issues of poor seed filling efficiency, low qualified seeding index, and high missed-seeding index in cassava precision planters, this study developed a dual-chamber pre-cut cassava stem filling mechanism. The structure and working principles were analyzed, identifying key factors affecting performance. By employing the discrete element method (DEM) to simulate the interaction between cassava seed stems and the filling mechanism, using statistical analysis to process experimental data, and adopting kinematic and mechanical equilibrium modeling for theoretical analysis, the structure and dimensions of the seed scoop were ultimately optimized. Subsequently, we evaluated the effects of the seed scoop speed in the first filling zone, the seed filling speed ratio, and the seed stem population thickness on performance through multi-factor simulation experiments. Based on the NSGA-II algorithm and the analytic hierarchy process, the optimal parameters were determined as follows: a seed filling speed ratio of 0.78, a seed scoop speed (first filling zone) of 0.6 m/s, and a seed stem population thickness of 290–320 mm. Bench tests under these conditions yielded a 95.31% qualified filling rate (ratio of single-segment cassava stem captured by seed scoop to total stems), 1.89% missed-filling rate (ratio of cassava stem not captured by seed scoop to total stems), and 2.80% double-filling rate (ratio of multi-segment cassava stem captured by seed scoop to total stems). Variety adaptability tests confirmed the mechanism’s robustness for precision planting. These findings offer theoretical guidance for precision planting of stalk-type crops.