A Manipulator-Assisted Multiple UAV Landing System for USV Subject to Disturbance

TL;DR

This paper introduces a tether-assisted manipulator system for stable multi-UAV landing on a USV affected by marine disturbances, enabling safe landings without enlarging the USV.

Contribution

It proposes a novel manipulator-assisted landing system with MPC control and adaptive disturbance estimation for USVs in rough sea conditions.

Findings

Successfully tested in field with 12-degree USV roll disturbance.

System can land multiple UAVs without increasing USV size.

Validated through simulations and indoor experiments.

Abstract

Marine waves significantly disturb the unmanned surface vehicle (USV) motion. An unmanned aerial vehicle (UAV) can hardly land on a USV that undergoes irregular motion. An oversized landing platform is usually necessary to guarantee the landing safety, which limits the number of UAVs that can be carried. We propose a landing system assisted by tether and robot manipulation. The system can land multiple UAVs without increasing the USV's size. An MPC controller stabilizes the end-effector and tracks the UAVs, and an adaptive estimator addresses the disturbance caused by the base motion. The working strategy of the system is designed to plan the motion of each device. We have validated the manipulator controller through simulations and well-controlled indoor experiments. During the field tests, the proposed system caught and placed the UAVs when the disturbed USV roll range was approximately 12 degrees.