Optimal Scheduling of a Dual-Arm Robot for Efficient Strawberry Harvesting in Plant Factories

Yuankai Zhu†, Wenwu Lu†, Guoqiang Ren, Yibin Ying, Stavros Vougioukas, Chen Peng*,
Zhejiang University and University of California, Davis
IEEE/RSJ International Conference on Intelligent Robots and Systems (iROS)-2025
†Indicates co-first authors*Indicates corresponding author
arXiv

Stop-and-harvest strategy for strawberry picking robot with dual arms. The robot harvests some fruits on both sides at one stop, then moves to the next until all are harvested.

Abstract

Plant factory cultivation is widely recognized for its ability to optimize resource use and boost crop yields. To fur- ther increase the efficiency in these environments, we propose a mixed-integer linear programming (MILP) framework that systematically schedules and coordinates dual-arm harvesting tasks, minimizing the overall harvesting makespan based on pre-mapped fruit locations. Specifically, we focus on a spe- cialized dual-arm harvesting robot and employ pose coverage analysis of its end effector to maximize picking reachability. Additionally, we compare the performance of the dual-arm configuration with that of a single-arm vehicle, demonstrating that the dual-arm system can nearly double efficiency when fruit densities are roughly equal on both sides. Extensive simulations show a 10–20% increase in throughput and a significant reduction in the number of stops compared to non- optimized methods. These results underscore the advantages of an optimal scheduling approach in improving the scalability and efficiency of robotic harvesting in plant factories.

Analysis of the Picking area for SCARA Arm

(a) The coverage area of different ways of picking for the SCARA robot arm: red represents the position arrival; yellow represents the end-effector can arrive in one angle among the range [-45°,45°]; blue represents the end-effector can arrive at 0°; green represents the end-effector can arrive at any angle between [-45°,45°]; (b) The coverage area where the end-effector can arrive at 0°, where orange represents the single-sided covering area.

Covering area of the dual robot arm

Reachable workspace of the SCARA robot arm in a cross-sectional plane, highlighting adjustments in the horizontal position (D) and rotation angles (θL and θR) for optimal alignment with the fruit distribution.

MILP planning results

Video Presentation

BibTeX

@ARTICLE{2507.04240,
                author={Yuankai Zhu, Wenwu Lu, Guoqiang Ren, Yibin Ying, Stavros Vougioukas, Chen Peng},
                Conference={2025 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)}, 
                title={Optimal Scheduling of a Dual-Arm Robot for Efficient Strawberry Harvesting in Plant Factories}, 
                year={2025},
                doi={https://doi.org/10.48550/arXiv.2507.04240}
              }