Development, integration, and field evaluation of an autonomous citrus‐harvesting robot

Abstract

Abstract Citrus harvesting is a labor‐intensive and time‐intensive task. As the global population continues to age, labor costs are increasing dramatically. Therefore, the citrus‐harvesting robot has attracted considerable attention from the business and academic communities. However, robotic harvesting in unstructured and natural citrus orchards remains a challenge. This study aims to address some challenges faced in commercializing citrus‐harvesting robots. We present a fully integrated, autonomous, and innovative solution for citrus‐harvesting robots to overcome the harvesting difficulties derived from the natural growth characteristics of citrus. This solution uses a fused simultaneous localization and mapping algorithm based on multiple sensors to perform high‐precision localization and navigation for the robot in the field orchard. Besides, a novel visual method for estimating fruit poses is proposed to cope with the randomization of citrus growth orientations. Further, a new end‐effector is designed to improve the success and conformity rate of citrus stem cutting. Finally, a fully autonomous harvesting robot system has been developed and integrated. Field evaluations showed that the robot could harvest citrus continuously with an overall success rate of 87.2% and an average picking time of 10.9 s/fruit. These efforts provide a solid foundation for the future commercialization of citrus‐harvesting robots.