Several physico-mechanical designs evolved in fish are currently inspiring robotic devices for propulsion and maneuvering purposes in underwater vehicles. Considering the potential benefits involved, this paper presents an overview of the swimming mechanisms employed by fish. The motivation is to provide a relevant and useful introduction to the existing literature for engineers with an interest in the emerging area of aquatic biomechanisms. The fish swimming types are presented, following the well-established classification scheme and nomenclature originally proposed by Breder. Fish swim either by body and/or caudal fin (BCF) movements or using median and/or paired fin (MPF) propulsion. The latter is generally employed at slow speeds, offering greater maneuverability and better propulsive efficiency, while BCF movements can achieve greater thrust and accelerations. For both BCF and MPF locomotion, specific swimming modes are identified, based on the propulsor and the type of movements (oscillatory or undulatory) employed for thrust generation. Along with general descriptions and kinematic data, the analytical approaches developed to study each swimming mode are also introduced. Particular reference is made to lunate tail propulsion, undulating fins, and labriform (oscillatory pectoral fin) swimming mechanisms, identified as having the greatest potential for exploitation in artificial systems.

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Review of fish swimming modes for aquatic locomotion

Unmanned surface vehicles: An overview of developments and challenges

We review a range of techniques related to navigation of unmanned vehicles through unknown environments with obstacles, especially those that rigorously ensure collision avoidance (given certain assumptions about the system). This topic continues to be an active area of research, and we highlight some directions in which available approaches may be improved. The paper discusses models of the sensors and vehicle kinematics, assumptions about the environment, and performance criteria. Methods applicable to stationary obstacles, moving obstacles and multiple vehicles scenarios are all reviewed. In preference to global approaches based on full knowledge of the environment, particular attention is given to reactive methods based on local sensory data, with a special focus on recently proposed navigation laws based on model predictive and sliding mode control.

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Algorithms for collision-free navigation of mobile robots in complex cluttered environments: a survey

To celebrate the 40th Anniversary of the Oceanic Engineering Society (OES) at the MTS/IEEE OCEANS 2008 Conference in Quebec City a series of review papers were requested from OES technical committee chairs. In response to that request this paper provides a review of the field of unmanned surface vehicles (USVs) and autonomous surface craft (ASCs). The paper discusses the enabling technologies that have allowed USVs to emerge as a viable platform for marine operations as well as the application areas where they offer value. The paper tracks developments in technology from early systems developed by the author in 1993 through the latest developments and demonstration programs. The future outlook for USV technology is also described.

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Unmanned surface vehicles, 15 years of development

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.

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

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.

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

Unmanned Surface Vehicle for Coastal and Protected Waters Applications: the Charlie Project

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.

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

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.

Variable-configuration UUVs for marine science applications

The design, development and exploitation of Romeo, a last generation ROV (remotely operated vehicle) capable of supporting robotics research on intelligent/autonomous vehicles and to execute scientific missions in very harsh environment, are presented. The system's mechanical and communication design is discussed with respect to basic end-user requirements. A three Local Area Networks system architecture is proposed, and the main sub-systems connected to the surface (supervision), on-board and lab Ethernet LANs are described. The vehicle's exploitation in scientific missions in harsh environment (Ross Sea in Antarctica), Internet-based mission control demonstrations and the integration with a multidisciplinary scientific and technological payload proved the capabilities of the proposed architecture in matching operational and research requirements.

Gi. Bruzzone

Papers

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

Unmanned Surface Vehicle for Coastal and Protected Waters Applications: the Charlie Project

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

Variable-configuration UUVs for marine science applications

Unmanned underwater vehicles for scientific applications and robotics research : The ROMEO project