Influence of Static and Dynamic Downwash Interactions on Multi-Quadrotor Systems

TL;DR

This paper analyzes the aerodynamic downwash interactions in multi-quadrotor systems using experimental data, aiming to improve formation control and operational density.

Contribution

It provides a comprehensive, data-driven characterization of downwash effects in multi-quadrotor configurations, informing better control strategies.

Findings

Quantified forces and torques during quadrotor interactions.

Mapped spatial features of downwash wake using PIV.

Data supports physics-based coordination strategies.

Abstract

Flying multiple quadrotors in close proximity presents a significant challenge due to complex aerodynamic interactions, particularly downwash effects that are known to destabilize vehicles and degrade performance. Traditionally, multi-quadrotor systems rely on conservative strategies, such as collision avoidance zones around the robot volume, to circumvent this effect. This restricts their capabilities by requiring a large volume for the operation of a multi-quadrotor system, limiting their applicability in dense environments. This work provides a comprehensive, data-driven analysis of the downwash effect, with a focus on characterizing, analyzing, and understanding forces, moments, and velocities in both single and multi-quadrotor configurations. We use measurements of forces and torques to characterize vehicle interactions, and particle image velocimetry (PIV) to quantify the spatial features of the downwash wake for a single quadrotor and an interacting pair of quadrotors. This data can be used to inform physics-based strategies for coordination, leverage downwash for optimized formations, expand the envelope of operation, and improve the robustness of multi-quadrotor control.