Towards Cooperative Transport of a Suspended Payload via Two Aerial Robots with Inertial Sensing

TL;DR

This paper presents a novel method enabling two aerial robots to cooperatively transport a suspended payload using only inertial sensing, with a lightweight estimator and controller validated through extensive flight experiments.

Contribution

It introduces a new approach for cooperative payload transport using inertial measurements and an EKF-based estimator, reducing sensing and computational needs.

Findings

Follower stabilizes payload with only IMU data

Successful flight experiments with one and two robots

Demonstrates autonomous cooperative transport feasibility

Abstract

This paper addresses the problem of cooperative transport of a point mass hoisted by two aerial robots. Treating the robots as a leader and a follower, the follower stabilizes the system with respect to the leader using only feedback from its Inertial Measurement Units (IMU). This is accomplished by neglecting the acceleration of the leader, analyzing the system through the generalized coordinates or the cables' angles, and employing an observation model based on the IMU measurements. A lightweight estimator based on an Extended Kalman Filter (EKF) and a controller are derived to stabilize the robot-payload-robot system. The proposed methods are verified with extensive flight experiments, first with a single robot and then with two robots. The results show that the follower is capable of realizing the desired quasi-static trajectory using only its IMU measurements. The outcomes demonstrate promising progress towards the goal of autonomous cooperative transport of a suspended payload via small flying robots with minimal sensing and computational requirements.