Leader-Follower 3D Formation for Underwater Robots

TL;DR

This paper presents a vision-based leader-follower control strategy enabling underwater robots to form complex 3D formations, demonstrated through physical experiments and simulations, advancing underwater swarm capabilities with minimal communication.

Contribution

Introduces a novel low-computation, vision-based leader-follower formation control method for underwater robots, enabling complex 3D formations in real and simulated environments.

Findings

Successful physical demonstration of 3D formations

Insights into formation stability under underwater conditions

Simulation results on formation convergence and stability

Abstract

The schooling behavior of fish is hypothesized to confer many survival benefits, including foraging success, safety from predators, and energy savings through hydrodynamic interactions when swimming in formation. Underwater robot collectives may be able to achieve similar benefits in future applications, e.g. using formation control to achieve efficient spatial sampling for environmental monitoring. Although many theoretical algorithms exist for multi-robot formation control, they have not been tested in the underwater domain due to the fundamental challenges in underwater communication. Here we introduce a leader-follower strategy for underwater formation control that allows us to realize complex 3D formations, using purely vision-based perception and a reactive control algorithm that is low computation. We use a physical platform, BlueSwarm, to demonstrate for the first time an experimental realization of inline, side-by-side, and staggered swimming 3D formations. More complex formations are studied in a physics-based simulator, providing new insights into the convergence and stability of formations given underwater inertial/drag conditions. Our findings lay the groundwork for future applications of underwater robot swarms in aquatic environments with minimal communication.