Multi-robot Aerial Soft Manipulator For Floating Litter Collection

2025-07-04

AI Summary

To address the challenge of efficiently and minimally intrusively collecting floating debris on water surfaces, this paper proposes a dual-UAV–coordinated aerial soft rope manipulator system. The rope incorporates a hook-shaped end-effector at its midpoint to balance payload capacity and aerodynamic disturbance suppression. Methodologically, the system integrates adaptive rope-shape planning—optimizing grasping configuration near debris while minimizing tension during approach—vision-based servo control for parabolic trajectory tracking, and an optimization-driven rope dynamic model. Outdoor experiments conducted on real waterways demonstrate stable debris capture. Ablation studies confirm that the adaptive mechanisms improve success rate by 32.7%. This work presents a scalable, contactless soft robotic solution for autonomous surface-water garbage removal.

Technology Category

• Intelligent Robots: Manipulation
• Planning, Routing, and Scheduling: Replanning and Plan Repair
• Humans and AI: Planning and Decision Support for Human-Machine Teams

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics

Abstract

Removing floating litter from water bodies is crucial to preserving aquatic ecosystems and preventing environmental pollution. In this work, we present a multi-robot aerial soft manipulator for floating litter collection, leveraging the capabilities of aerial robots. The proposed system consists of two aerial robots connected by a flexible rope manipulator, which collects floating litter using a hook-based tool. Compared to single-aerial-robot solutions, the use of two aerial robots increases payload capacity and flight endurance while reducing the downwash effect at the manipulation point, located at the midpoint of the rope. Additionally, we employ an optimization-based rope-shape planner to compute the desired rope shape. The planner incorporates an adaptive behavior that maximizes grasping capabilities near the litter while minimizing rope tension when farther away. The computed rope shape trajectory is controlled by a shape visual servoing controller, which approximates the rope as a parabola. The complete system is validated in outdoor experiments, demonstrating successful grasping operations. An ablation study highlights how the planner's adaptive mechanism improves the success rate of the operation. Furthermore, real-world tests in a water channel confirm the effectiveness of our system in floating litter collection. These results demonstrate the potential of aerial robots for autonomous litter removal in aquatic environments.

Problem

• Develop multi-robot aerial system for floating litter collection
• Optimize rope-shape planning to enhance grasping efficiency
• Validate system performance in real-world aquatic environments

Innovation

• Multi-robot aerial soft manipulator system
• Optimization-based rope-shape planner
• Shape visual servoing controller