Online Adaptation for Flying Quadrotors in Tight Formations

TL;DR

This paper introduces an adaptive control framework for quadrotors flying in tight formations, effectively handling aerodynamic disturbances and maintaining formation stability through real-time adaptation.

Contribution

The paper presents L1 KNODE-DW MPC, a novel adaptive control method that improves trajectory tracking and disturbance compensation in formation flying of quadrotors.

Findings

Outperforms several MPC baselines in formation flight tasks.

Enables quadrotors to remain aligned in close proximity.

Effectively compensates for unmodeled aerodynamic disturbances.

Abstract

The task of flying in tight formations is challenging for teams of quadrotors because the complex aerodynamic wake interactions can destabilize individual team members as well as the team. Furthermore, these aerodynamic effects are highly nonlinear and fast-paced, making them difficult to model and predict. To overcome these challenges, we present L1 KNODE-DW MPC, an adaptive, mixed expert learning based control framework that allows individual quadrotors to accurately track trajectories while adapting to time-varying aerodynamic interactions during formation flights. We evaluate L1 KNODE-DW MPC in two different three-quadrotor formations and show that it outperforms several MPC baselines. Our results show that the proposed framework is capable of enabling the three-quadrotor team to remain vertically aligned in close proximity throughout the flight. These findings show that the L1 adaptive module compensates for unmodeled disturbances most effectively when paired with an accurate dynamics model. A video showcasing our framework and the physical experiments is available here: https://youtu.be/9QX1Q5Ut9Rs