Time-Varying Formation Control of Autonomous Surface Vehicles Based on Affine Observer

This article addresses an affine-formation tracking control (AFTC) of underactuated autonomous surface vehicles (ASVs). A distributed observer is developed to estimate desired formation positions via an affine transformation. A trajectory tracking controller with prescribed-performance is designed to steer the ASV fleet with a time-varying formation pattern. Sufficient conditions are derived to guarantee the asymptotical stability of the closed-loop system governed by AFTC. Both numerical simulation and experimental results with five ASVs on a platform are elaborated to substantiate the effectiveness and superiority of the proposed AFTC method for achieving time-varying formation through narrow waterways.