Distributed Oscillatory Guidance for Formation Flight of Fixed-Wing Drones

TL;DR

This paper introduces a novel oscillatory guidance algorithm enabling fixed-wing drones to achieve formation flight without speed actuation, using a superposed oscillation on guiding vectors for coordinated path following.

Contribution

It presents a new control method that guides fixed-wing drones in formation without requiring actuation over their speed, employing a unique consensus algorithm with asymmetric saturation.

Findings

Algorithm successfully coordinates drones in simulations and real-world tests.

Drones maintain formation without speed actuation.

The consensus algorithm ensures stable and distributed amplitude adjustment.

Abstract

The autonomous formation flight of fixed-wing drones is hard when the coordination requires the actuation over their speeds since they are critically bounded and aircraft are mostly designed to fly at a nominal airspeed. This paper proposes an algorithm to achieve formation flights of fixed-wing drones without requiring any actuation over their speed. In particular, we guide all the drones to travel over specific paths, e.g., parallel straight lines, and we superpose an oscillatory behavior onto the guiding vector field that drives the drones to the paths. This oscillation enables control over the average velocity along the path, thereby facilitating inter-drone coordination. Each drone adjusts its oscillation amplitude distributively in a closed-loop manner by communicating with neighboring agents in an undirected and connected graph. A novel consensus algorithm is introduced, leveraging a non-negative, asymmetric saturation function. This unconventional saturation is justified since negative amplitudes do not make drones travel backward or have a negative velocity along the path. Rigorous theoretical analysis of the algorithm is complemented by validation through numerical simulations and a real-world formation flight.