A SPH-YOLOv5x-Based Automatic System for Intra-Row Weed Control in Lettuce

Abstract

Weeds have a serious impact on lettuce cultivation. Weeding is an efficient way to increase lettuce yields. Due to the increasing costs of labor and the harm of herbicides to the environment, there is an increasing need to develop a mechanical weeding robot to remove weeds. Accurate weed recognition and crop localization are prerequisites for automatic weeding in precision agriculture. In this study, an intra-row weeding system is developed based on a vision system and open/close weeding knives. This vision system combines the improved you only look once v5 (YOLOv5) identification model and the lettuce–weed localization method. Compared with models including YOLOv5s, YOLOv5m, YOLOv5l, YOLOv5n, and YOLOv5x, the optimized SPH-YOLOv5x model exhibited the best performance in identifying, with precision, recall, F1-score, and mean average precision (mAP) value of 95%, 93.32%, 94.1% and 96%, respectively. The proposed weed control system successfully removed the intra-row weeds with 80.25% accuracy at 3.28 km/h. This study demonstrates the robustness and efficacy of the automatic system for intra-row weed control in lettuce.