Static and dynamic cutting forces in coriander crop harvesting: Engineering insights for harvester optimization

Abstract

The study investigates the mechanical requirements for harvesting coriander (Coriandrum sativum L.) by analyzing static and dynamic cutting forces for three distinct varieties: SIMCO, GCr1, and GCr2. Through controlled laboratory experiments, the static cutting force was measured using a texture analyzer across variations in blade speed (2, 4, 6, 8, and 10 mm/s), stem number (1–5), cutting height (50, 75, 100, 125, and 150 mm), and moisture content (23 %, 30 %, and 37 %). The static cutting force for SIMCO was found to be the highest (151.6 N), followed by GCr1 (145.68 N) and GCr2 (140.48 N), primarily due to stem structure and diameter differences. The dynamic cutting force was also measured in the indoor soil bin using a reciprocating cutter bar by simulating the field conditions at varied forward speeds (0.3, 0.6, 0.9, and 1.2 m/s), cutter bar speeds (2, 8, 14, and 20 strokes/s), and cutting heights (50, 75, 100, 125, and 150 mm). For dynamic cutting, the SIMCO variety required an average maximum force of 33.14 N, which was 6.85 % and 7.06 % higher than GCr1 and GCr2 respectively. The dynamic cutting forces were influenced most significantly by cutter bar speed and forward speed, with optimal cutting achieved at 20 strokes/s cutter bar speed and 0.3 m/s forward speed. Response Surface Methodology (RSM) models with R² values above 0.99 effectively predicted both static and dynamic cutting forces, indicating strong model adequacy and providing detailed insights into the interactions between parameters. The analysis revealed that the number of stems and blade speed were the primary influencers on static cutting force, while the dynamic force was most affected by cutter bar speed and forward speed. This study highlights the importance of customized parameter settings to enhance harvester efficiency, reduce energy consumption, and minimize seed damage during harvest.