R. Bono

Basic navigation, guidance and control of an Unmanned Surface Vehicle

This paper discusses the navigation, guidance and control (NGC) system of an Unmanned Surface Vehicle (USV) through extended at sea trials carried out with the prototype autonomous catamaran Charlie. In particular, experiments demonstrate the effectiveness, both for precision and power consumption, of extended Kalman filter and simple PID guidance and control laws to perform basic control tasks such as auto-heading, auto-speed and straight line following with a USV equipped only with GPS and compass.

Sampling sea surfaces with SESAMO: an autonomous craft for the study of sea-air interactions

This paper presents the system design, sea trials and Antartic exploitation of the SESAMO platform. The SESAMO (sea surface autonomous modular unit) prototype robot was especially designed to collect data and samples for the study of the sea-air interface. At sea, operations showed that a relatively simple robot could satisfactorily work in a natural, outdoor environment, dramatically facilitating the job of the human operator. To achieve high quality sampling of the surface microlayer, however, requires a large amount of time, leading to significant demands on logistics resources, mainly in terms of operating time of the support vessel.

Variable-configuration UUVs for marine science applications

In this article, after a brief overview of trends in underwater unmanned vehicle (UUV) design and applications, results in developing an automatic guidance and control system for Romeo are presented. Attention is focused on the design, development, and testing in the operating conditions of a bottom and ice-canopy following system and on the development of methodologies for the at-field identification of the vehicle dynamics in order to guarantee high motion-control performance, even in the presence of variations in the vehicle configuration. In particular, the system performance in the proximity of the coast, where there is only a very shallow column of free water between the ice-pack and the sea-bed, is discussed.

A Practical Approach to Modeling and Identification of Small Autonomous Surface Craft

This paper discusses the theoretical model of an autonomous surface craft (ASC) with respect to the performance of basic sensors usually available onboard small and relatively low- cost vessels. The aim is to define a practical model and the corresponding identification procedure for simulation, guidance, and control of this class of vehicles. The work is supported by the extended at-sea trials carried out with the autonomous catamaran prototype Charlie2005.

Design and Exploitation of an Autonomous Surface Vessel for the Study of Sea-Air Interactions

The design, development, sea trials and exploitation of the SESAMO (SEa Surface Autonomous MOdular unit) platform, an autonomous surface vessel for the study and characterization of the air-sea interface, are presented. The SESAMO prototype robot, developed by the robotics group of CNR-ISSIA, Genova branch, in strict cooperation with the scientific end-users in the framework of a project of the Italian National Program of Research in Antarctica (PNRA), was able to sample the sea surface microlayer and immediate sub-surface. After satisfactory basic at field trials of the navigation, guidance and control (NGC) and sampling systems, the robotised catamaran was exploited by the scientific end-users for water sample collection in the area of Terra Nova Bay, Ross Sea, Antarctica, in the framework of the PNRA project Chemical contamination.

Modelling and identification of the Charlie2005 ASC

This paper discusses a practical model, with respect to the performance of basic sensors available on-board the vessel, and the corresponding identification procedure for guidance and control of the Charlie2005 ASC. The work is supported by extended at sea trials

Romeo goes to Antarctica [unmanned underwater vehicle]

Deals with the first operational campaign of Romeo, the latest unmanned underwater vehicle developed at CNR-IAN. Romeo has been designed as an operational testbed to perform research on intelligent vehicles in the real subsea environment. Its main application field is the development of advanced methodologies for marine science. A brief description of the mechanical design and of the control, computing and software architecture of Romeo is given and its exploitation in Antarctica is reported. During the XIII Italian Expedition to Terra Nova Bay (29 October 1997-26 February 1998) it has been used for (a) collecting data about under-ice biological processes, (b) testing under-ice performances of a set of acoustic devices for autonomous navigation and guidance, and (c) collecting benthic data in the Marine Antarctic Specially Protected Area established near the Italian TNB Station.

ROV actuator fault diagnosis through servo-amplifiers' monitoring: an operational experience

A system for ROV actuator fault detection, diagnosis and accommodation through servo-amplifier monitoring and dedicated steady-state maneuvers has been designed on the basis of real data recorded during operating missions of Romeo, the ROV prototype developed by CNR-IAN. In particular, an actuator fault during sea operations of Romeo enabled the validation with real data of the developed system.

A simulation environment for unmanned underwater vehicles development

Logistics problems and high costs necessary to carry out experiments with robots in hazardous environments such as the open sea led to the development of simulation environments (SE) where the physical robot and the operating environment can be substituted by real-time simulators in a way that is completely transparent to the robots control and sensing modules. SEs are extremely useful tools which allow to rapidly designing, developing, testing and evaluating in lab the working of an underwater vehicle and to minimise the risks to lose expensive equipment during in field testing. In this paper the SE developed by the National Research Council, Institute for Ship Automation of Genoa (CNR-IAN) will be presented.

Reconstructing 2-D maps from multiple sonar scans

The Naval Automation Institute (IAN) of the Italian National Research Council has been carrying out some activities in the field of underwater robotics. The ultimate goal is the development of an autonomous underwater vehicle for research purposes. The paper presents the activity of the IAN in the field of the reconstruction of underwater scenes using sonar. The authors work with real data taken using a high-frequency pencil beam profiling sonar manually positioned in a laboratory tank. The goal is to build a model of the surroundings as a two dimensional map, which could be used by an autonomous vehicle to plan, on-line, the path to reach a target point. At first they describe the basic geometric elements used to model the environment and the synthetic information associated with them. The description of an algorithm to extract basic geometric elements from a single sonar scansion is followed by the presentation of a method to merge the processed data of many scansions to build a more complex 2-D map detecting false echoes.<<ETX>>