Formation Control for Moving Target Enclosing via Relative Localization

TL;DR

This paper presents a distributed control method for UAVs to enclose a moving target using relative localization and a coupled oscillator model, with theoretical analysis, simulations, and real-world experiments demonstrating effectiveness.

Contribution

It introduces a novel combined approach of relative localization via RLSE and coupled oscillator-based formation control for moving target enclosure.

Findings

The proposed localization achieves accurate relative position estimates.

The formation control ensures convergence of UAVs around the target.

Experimental results validate the method on real quadrotors.

Abstract

In this paper, we investigate the problem of controlling multiple unmanned aerial vehicles (UAVs) to enclose a moving target in a distributed fashion based on a relative distance and self-displacement measurements. A relative localization technique is developed based on the recursive least square estimation (RLSE) technique with a forgetting factor to estimates both the ``UAV-UAV'' and ``UAV-target'' relative positions. The formation enclosing motion is planned using a coupled oscillator model, which generates desired motion for UAVs to distribute evenly on a circle. The coupled-oscillator-based motion can also facilitate the exponential convergence of relative localization due to its persistent excitation nature. Based on the generation strategy of desired formation pattern and relative localization estimates, a cooperative formation tracking control scheme is proposed, which enables the formation geometric center to asymptotically converge to the moving target. The asymptotic convergence performance is analyzed theoretically for both the relative localization technique and the formation control algorithm. Numerical simulations are provided to show the efficiency of the proposed algorithm. Experiments with three quadrotors tracking one target are conducted to evaluate the proposed target enclosing method in real platforms.