Flow-Based Control of Marine Robots in Gyre-Like Environments

TL;DR

This paper introduces a flow-based control method for marine robots that allows them to efficiently patrol gyre-like environments without detailed flow models, leveraging environmental flow to reduce control effort and ensure periodic trajectories.

Contribution

The paper presents a novel flow-based control strategy that does not require detailed flow models and enables resource-constrained robots to maintain periodic orbits in gyre-like flows.

Findings

Successfully validated in simulation and experiments

Enables robots to cycle with desired periodicity

Reduces control effort by leveraging flow environment

Abstract

We present a flow-based control strategy that enables resource-constrained marine robots to patrol gyre-like flow environments on an orbital trajectory with a periodicity in a given range. The controller does not require a detailed model of the flow field and relies only on the robot's location relative to the center of the gyre. Instead of precisely tracking a pre-defined trajectory, the robots are tasked to stay in between two bounding trajectories with known periodicity. Furthermore, the proposed strategy leverages the surrounding flow field to minimize control effort. We prove that the proposed strategy enables robots to cycle in the flow satisfying the desired periodicity requirements. Our method is tested and validated both in simulation and in experiments using a low-cost, underactuated, surface swimming robot, i.e. the Modboat.