A Breeding Cotton Harvesting Robot: Design, Integration, and Field Evaluation

ABSTRACT Inconsistent boll maturity and uncertain environmental factors prevent large cotton mechanical harvesters from multiple batches harvesting with high quality. It is a challenge to develop harvesting robots for small patches and scattered cultivation of cotton, especially in rainy and windy cotton planting areas. To address the problem of cotton harvest in breeding fields of limited size, a novel design of cotton multi‐batch harvesting robot is presented and evaluated in the field. First, after the analysis of the growth characteristics of cotton bolls, a five‐picking‐zones (FPZ) based end‐effector, a T‐bot‐based three degree‐of‐freedom robotic arm, and cotton seed removal unit are designed to ensure the convenient picking of cotton bolls in multiple growth postures. Second, a robotic visual perception system based on depth camera and YOLOv8 detection model is developed to localize cotton bolls in complex field environments. Then, a picking sequence planning method and ROS2‐based cotton‐picking control process are proposed. Finally, an integrated cotton selective harvesting robot prototype is built to validate by picking assessment criteria. The test results show that the single picking time by FPZ of the end‐effector ranges from 2.3 to 2.88 s, and its harvest integrity rate ranges from 97% to 98.2%. The optimal configuration of end‐effector based on multivariate regression analysis results in 15 mm needle length, 15 mm needle spacing, and a motor speed of 215 rpm for the picking belt. Indoor and field experiments demonstrate the performance with an average picking time of 2.5 s indoors and 3.35 s in the field, about 78.5% of visible cotton targets were detected, of which 86.3% of the detected cotton targets were correctly identified, 86.7% of the harvest integrity rate after identification, and 94.4% of the one‐shot harvesting rate during the field trials. This research highlights the potential of robotic picking to improve cotton breeding and offers a sustainable alternative to manual labor for size‐limited cotton harvest.