Cooperative decentralized circumnavigation with application to algal bloom tracking

TL;DR

This paper presents a decentralized multi-robot control method for tracking and circumnavigating dynamic algal blooms, combining satellite data, local sensing, and control algorithms to ensure reliable monitoring.

Contribution

It introduces a novel decentralized control algorithm for multi-robot circumnavigation of dynamic targets, with proven convergence and simulation validation.

Findings

Robots successfully circumnavigate dynamic algal bloom models.

The control algorithm guarantees convergence to the target circle.

Simulation results validate the theoretical convergence and spacing.

Abstract

Harmful algal blooms occur frequently and deteriorate water quality. A reliable method is proposed in this paper to track algal blooms using a set of autonomous surface robots. A satellite image indicates the existence and initial location of the algal bloom for the deployment of the robot system. The algal bloom area is approximated by a circle with time varying location and size. This circle is estimated and circumnavigated by the robots which are able to locally sense its boundary. A multi-agent control algorithm is proposed for the continuous monitoring of the dynamic evolution of the algal bloom. Such algorithm comprises of a decentralized least squares estimation of the target and a controller for circumnavigation. We prove the convergence of the robots to the circle and in equally spaced positions around it. Simulation results with data provided by the SINMOD ocean model are used to illustrate the theoretical results.