Modeling and identification of open-frame variable configuration unmanned underwater vehicles

TLDR

The paper presents a lumped‑parameter model of open‑frame UUVs that incorporates propeller‑hull and propeller‑propeller interactions. The model parameters are identified by a least‑squares method using only on‑board sensor data, with separate tests for drag and thruster coefficients that first account for propeller‑hull and propeller‑propeller effects and then for inertia. Experimental tests on the ROMEO UUV confirm the method’s effectiveness and demonstrate that propeller‑hull and propeller‑propeller interactions, often ignored in standard models, significantly influence vehicle dynamics.

Abstract

A lumped parameter model of open-frame unmanned underwater vehicles (UUV's) including the effects of propeller-hull and propeller-propeller interactions is presented. The identification of the model parameters consists of a least squares method using only on-board sensor data without requiring any towing tank tests. The identification scheme is based on separate tests for the estimation of drag and thruster installation coefficients, taking into account propeller-hull and propeller-propeller effects first and inertia parameters subsequently. The scheme has been experimentally implemented on ROMEO, the latest UUV developed by CNR-IAN. Experimental results show both the effectiveness of the proposed method and the relevance of the propeller-hull and propeller-propeller interactions that are usually neglected in standard UUV models.