Geometric Control of a Quadrotor UAV Transporting a Payload Connected via Flexible Cable

TL;DR

This paper develops a geometric control framework for a quadrotor UAV transporting a payload via a flexible cable, modeling the cable dynamics and providing stability analysis with simulations and experiments.

Contribution

It introduces a coordinate-free dynamic model including flexible cable effects and a nonlinear control system for stable payload transportation.

Findings

Successful stabilization of quadrotor with flexible cable payload

Validated control system through simulations and experiments

Confirmed exponential stability with rigorous analysis

Abstract

We derived a coordinate-free form of equations of motion for a complete model of a quadrotor UAV with a payload which is connected via a flexible cable according to Lagrangian mechanics on a manifold. The flexible cable is modeled as a system of serially-connected links and has been considered in the full dynamic model. A geometric nonlinear control system is presented to exponentially stabilize the position of the quadrotor while aligning the links to the vertical direction below the quadrotor. Numerical simulation and experimental results are presented and a rigorous stability analysis is provided to confirm the accuracy of our derivations. These results will be particularly useful for aggressive load transportation that involves large deformation of the cable.