Performance evaluation of an electric seed metering device for precision maize planting using an agricultural robot

Abstract

Precision seed placement is a key requirement for precision maize planting in autonomous agricultural systems. This study presents the design and performance evaluation of an electrically driven seed metering device integrated into a solar-powered agricultural robot for precision maize planting. The metering unit was experimentally evaluated under controlled conditions at four forward speeds (0.42–1.60 km h⁻¹) and four target intra-row spacings (10–25 cm). Metering performance was assessed using standard indices, including miss index, multiple index, precision index, seed rate, and spacing accuracy, following ISO-based procedures. The results showed stable and accurate seed delivery across the tested operating range, with miss index below 2%, multiple index below 2.5%, and spacing accuracy ranging from 98.08 to 98.80%. Analysis of variance revealed that robot forward speed significantly affected multiple and precision indices (p < 0.05), whereas target seed spacing had a comparatively smaller effect. Optimal performance was achieved at forward speeds of 0.82–1.20 km h⁻¹ and target spacings of 15–20 cm, where spacing variability was minimized, and planting uniformity was maximized. The close agreement between theoretical and measured seed rates confirmed effective synchronization between metering-disc rotation and robot travel speed. In addition, the solar-powered robotic system operated with low energy consumption (48–84 W) and high solar energy utilization efficiency (95–167%), demonstrating its operational feasibility and sustainability. Overall, the developed electric seed-metering device provides accurate, reliable, and energy-efficient seed placement, making it suitable for precision maize planting in autonomous agricultural robotics.