Marine litter poses a significant environmental threat, with detrimental effects on marine ecosystems through toxic chemical release, entanglement, ingestion by marine life, and microplastic formation. Floating waste collection devices, such as the Waste Out of Water (WoW) system developed by the University of Florence, offer a solution by intercepting debris before it disperses into open waters. The WoW device employs a buoyant sliding-cylinder mechanism to regulate water inflow, driven by water level variations, while a pump-controlled outflow directs polluted water to a filtration system. This study proposes a fluid-dynamic model of the WoW system, incorporating factors such as inflow dynamics, outflow regulation, buoyancy, friction, and motion constraints. The model is treated as a grey-box, the parameters are estimated through the solution to an optimization problem in the frequency domain, and the model is validated against experimental data collected during the device operation. Moreover, a simple PID control strategy is implemented in the simulation to show the potential ability to control the device to an operational point of interest. These findings provide useful insights into improving floating waste collection devices and their deployment for effective marine pollution mitigation.

In the last few years, marine litter has been drawing considerable attention due to the negative effects it has on the marine environment. Water properties alteration, fish entanglement and generation of microplastics are just some of the problems marine litter causes, requiring scientific research to provide solutions to address this issue. Most of the waste that ends up in seas and oceans is actually produced by land-based activities. Therefore, one way of addressing the problem is trying to collect as much litter as possible before it goes into the open sea or sinks to the bottom. With this aim, the proposed Waste out of Water (WoW) electromechanical solution skims the surface of calm marinas (i.e. ports or lagoons) and collects floating litter such as plastic bags, cigarette butts, microplastics, hydrocarbons and oil in a container placed on the dock, where they can eventually be sorted. The proposed device builds on top of state-of-the-art devices trying to address some of their most common problems such as frequent clogging and high power consumption. The contribution of this work is to present the early-stage development of the Waste out of Water solution. The downstream filtering and the employment of the platform as a stand-alone device show promising results for future developments.

Modern mobile robots require precise and robust localization and navigation systems to perform their missions correctly. Especially in the underwater environment, where global localization sensors such as the Global Navigation Satellite System (GNSS) cannot be exploited, the development of localization and navigation strategies becomes more challenging.A small towed buoy has been designed and realized to work as interface unit between an Autonomous Underwater Vehicle (AUV) and its control station. A GNSS sensor, installed over the buoy, provides the vehicle with a reliable position measure to be used either to improve its localization accuracy or just as a safety measure flagging whether its localization algorithms are somehow failing. Furthermore, the device enables Wi-Fi communication with the control station while the vehicle is performing its underwater inspection tasks, allowing real-time visualization of the data acquired by payload sensors.The towed buoy is equipped with 4 LEDs placed in square shape structure that can be detected by a camera placed on top of the AUV. A strategy based on the Perpective-n-Point (PnP) problem has been developed to transfer the original GNSS measure of the buoy to the vehicle.The position measure is then used in an Unscented Kalman Filter (UKF) which estimates the vehicle position. The resulting navigation methodology has been validated offline by employing the sensor measurement values logged during past on-field missions of FeelHippo AUV, a lightweight and compact robot developed by the Department of Industrial Engineering of the University of Florence (UNIFI DIEF).

The development of vehicles incorporating both the Autonomous Underwater Vehicle (AUV) and the Remotely Operated Vehicles (ROV) intervention functionalities can be considered one of the most investigated tasks of the underwater industry and the scientific community. A feasible solution can be the development of Autonomous Underwater Reconfigurable Vehicles (AURVs), i.e. vehicles that can change their current configuration depending on the demanded task. Driven by these considerations, an innovative AURV has been developed by the Department of Industrial Engineering of the University of Florence (DIEF), Italy, capable of efficiently reconfiguring its shape according to the task at hand. In particular, the RUVIFIST (Reconfigurable Underwater Vehicle for Inspection, Free-floating Intervention and Survey Tasks) vehicle has been provided with two extreme configurations: a slender ("survey") configuration for long navigation tasks and a stocky ("hovering") configuration designed for challenging goals as intervention operations. Consequently, this work presents the results obtained during several experimental campaigns conducted to accurately test the vehicle reconfigurable system and how the standard Guidance, Navigation and Control (GNC) strategies must be adapted for AURVs.

The paper presents the electromechanical design of a vision system, developed by the ISME nodes of the University of Florence (UNIFI) and the University of Pisa (UNIPI), Italy. The main objective is to design a platform to test Visual Odometry algorithms that can be employed both as a standalone device or in conjunction with an Autonomous Underwater Vehicle (AUV); in this regard, the module presents a wide variety of sensors and is designed to have its own power supply. The project constraints are described and the main features of the final design are reported. The mechanical and electrical assemblies are presented together with the main static and fluid dynamics analyses. The module will be assembled and tested during Spring 2022.

Since the development of the first Autonomous Underwater Vehicles (AUVs), the demanded tasks for subsea operations have become more and more challenging as, for instance, intervention, maintenance and repair of seabed installations, in addition to surveys. As a result, the development of Autonomous Underwater Reconfigurable Vehicles (AURVs) with the capability of interacting with the surrounding environment and autonomously changing their configuration, according to the task at hand, can represent a real breakthrough in underwater system technologies. Driven by these considerations, an innovative AURV has been developed by the Department of Industrial Engineering of the University of Florence (DIEF), Italy, capable of efficiently reconfiguring its shape according to the task at hand. In particular, the RUVIFIST (Reconfigurable Underwater Vehicle for Inspection, Free-floating Intervention and Survey Tasks) vehicle has been provided with two extreme configurations: a slender ("survey") configuration for long navigation tasks, and a stocky ("hovering") configuration designed for challenging goals as intervention operations. In particular, an accurate description of the overall vehicle is currently provided in this work, along with several preliminary tests.

In the last decades, the demanded tasks for subsea operations have become more and more challenging as, for instance, intervention, maintenance and repair of seabed installations. These activities are becoming more typical for the underwater offshore industry, search-and-rescue operations, or underwater scientific missions. Motivated by these considerations, this paper presents an overview of the Italian SUONO (Safe Underwater Operations iN Oceans) project, which involves the Department of Industrial Engineering (DIEF) of the University of Florence, a node of the Italian Research Center on Integrated System for the Marine Environment (ISME), Italy, and four other Italian partners, from Academia as well as Industry. More in detail, the SUONO project aims to integrate technologies and methodologies to enable the development of autonomous underwater robotic systems employable for intervention activities as, for instance, a free-floating manipulation task on a subsea panel. As a result, the whole control strategy must also consider all of a series of different objectives, starting from operational to safety aspects. Examples of such goals are reaching the desired end-effector pose and keeping the robotic arm joints far from the physical limits. The proposed methodology is based on the well-known Task Priority Inverse Kinematics (TPIK) framework, which also enables the possibility to handle inequality constraints. Additionally, a perception system, able to accurately understanding and managing the surrounding environment, is hereby presented. Finally, the preliminary results, supporting the proposed control strategy and the perception architecture, are presented and motivated in detail.

The number of Years Lived with Disability (YLDs) is growing at an impressive pace under the aging global population's push. Consequently, the demand for innovative therapies and solutions to improve the quality of life of disabled people is rising. Robots are making their way into the clinical sector to provide high-intensity rehabilitation exercises or assistance while monitoring quantitative metrics for tracking the patients' status evolution. Exoskeletons are among the most studied and most interesting embodiments of today's robotic technologies. This paper investigates an innovative design concept for a rehabilitative Hand Exoskeleton System (HES) driven by a Remote Actuation System (RAS). The discussion starts from the characteristics of a previously built prototype and focuses on using finite element analysis, topological optimization techniques, and 3D-printing-oriented design to minimize the system's weight and complexity while assuring adequate performance to be effective in rehabilitation. The text will present, in sequence: the main features of the starting prototype; the preliminary design of the new exoskeleton; a detailed dynamic analysis of the finger mechanisms composing it; the final topologically optimized design; and, finally, the evaluation of the result of the redesign process.

The paper presents the electromechanical design of an Autonomous Surface Vehicle (ASV) developed by the Department of Industrial Engineering (DIEF) of the University of Florence (UNIFI), Italy. One of the main functions of this autonomous moving buoy is to localize underwater targets, such as Autonomous Underwater Vehicles (AUVs), through an Ultra Short BaseLine (USBL) and to enable the communication with them; furthermore, it is possible to equip the buoy with sensors or payloads, for instance cameras to detect the seabed. The buoy specifications and its navigation devices are described. The main features of the developed floating device are given, starting from its system architecture to its structural design. The buoy will be assembled during Summer 2019 and tested together with the UNIFI DIEF underwater vehicles.

This paper describes design methods for the plastic hull of an Unmanned Underwater Vehicle (UUV), with a particular focus on its cylindrical body and nearly spherical domes at the ends. With the proposed approach, the methodologies reported in the literature were compared, and suitable modifications and improvements were investigated and implemented to extend the classical theories and data to this case study. The investigated underwater vehicle, named FeelHippo, was designed and assembled by the Department of Industrial Engineering of the University of Florence. Its main hull is composed of an extruded PMMA (PolyMethyl MethAcrylate) cylinder and two thermoformed PMMA domes. Breakage of the hull results in destructive phenomena, namely, yielding and buckling. An experimental campaign and FEM (Finite Element Method) analysis were carried out to complete the theoretical study, and the collapse pressures were compared with the derived design values. In conclusion, the proposed innovative method is a lean and effective technique for designing underwater hull domes and predicting the collapse pressures.

A new type of vehicle has been designed by the Department of Industrial Engineering of the University of Florence (DIEF); it is an AUV (Autonomous Underwater Vehicle) capable of switching its shape according to mission needs matching the best UUVs (Unmanned Underwater Vehicles) features: it is compact and near torpedo-shaped in case of long distance missions, such as surveillance and monitoring (closed configuration, typical of AUVs), on the other end it becomes isotropic for site inspection and on-site manipulation (open configuration, emblem of ROVs - Remotely Operated Vehicles). The main goal of the work is adding to the hydrodynamic vehicle the capability of changing its structure and its thruster configuration. The paper deals with the study and the design of the vehicle. Its main features, design choices and payloads, that can be equipped with, are described.

Zeno (Zeno Environment Nautical Operator) is a compact AUV (Autonomous Underwater Vehicle) designed by the Department of Industrial Engineering of the University of Florence (UNIFI) and MDM Team S.r.l., an official spin-off company of UNIFI, within the ARCHEOSUb (Autonomous underwater Robotic and sensing systems for Cultural HEritage discovery cOnservation and in SitU valorization) European project and tailored for archaeological missions. One of the main purposes of this project is to develop low-cost AUVs, both used as a tool for services supporting the identification of new Underwater Cultural Heritage (UCH) sites and for the conservation, protection and enhancement of new and discovered ones (covering the first two phases of an archaeological campaign: search and inspection). The paper deals with the design, realization and testing of the vehicle. Its main features, payloads and implementation details are given. The official demos have already started and will be completed in autumn 2018; the different archaeological sites involved are in Italy and in Israel.

The paper describes the electromechanical design of a compact, light-weight Autonomous Underwater Vehicle (AUV) for archaeological applications; the vehicle is named Zeno (Zeno Environment Nautical Operator), protector of freshwater and flood victims, and was developed in the framework of the European project ARCHEOSUb; the AUV specifications, its navigation devices and payload are given. The main characteristics of the vehicle are described with particular attention to its system architecture, propulsion system and structural design. Zeno AUV is currently under assembly and its first tests are scheduled for Summer 2018.

Autonomous underwater navigation remains, as of today, a challenging task. The marine environment limits the number of sensors available for precise localization, hence Autonomous Underwater Vehicles (AUVs) usually rely on inertial and velocity sensors to obtain an estimate of their position either through dead reckoning or by means of more sophisticated navigation filters (such as Kalman filters and its extensions [1]). On the other hand, acoustic localization makes possible the determination of a reliable vehicles pose estimate exploiting suitable acoustic modems [3]; such estimate can even be integrated within the navigation filter of the vehicle in order to increase its accuracy. In this paper, the authors discuss the development and the performance of an Ultra-Short BaseLine (USBL)-aided buoy to improve the localization of underwater vehicles. At first, the components and the physical realization of the buoy will be discussed; then, the procedure to compute the position of the target will be analyzed. The following part of the paper will be focused on the development of a recursive state estimation algorithm to process the measurements computed by the buoy; specifically, Extended Kalman Filter [4] has been adopted to deal with the nonlinearities of the sensors housed on the buoy. A validation of the measurement filtering through experimental tests is also proposed.

Nowadays, underwater acoustic communication is an interesting topic of research. This is especially true in the case of Autonomous Underwater Vehicles (AUVs): due to the limitations of underwater environment, where wireless and radio communications are not possible, it is very important to possess efficient and reliable tools for acoustic data exchange. Indeed, an underwater network of acoustic nodes can enhance the navigation and localization capabilities of one or more vehicles. In this paper, the authors investigate the use of an AUV as a mobile bridging node within a network of fixed heterogeneous acoustic modems. In particular, MARTA AUV, developed and built by the Department of Industrial Engineering (DIEF) of the University of Florence is employed in order to enable data transmission between modems of different manufacturers. Suitable bridging tests, whose results are proposed in this paper, were executed in order to evaluate the feasibility of such approach, showing that AUVs can efficiently accomplish the role of gateway between the nodes of the network. (C) 2017, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

The paper describes the development and the main characteristics of a low-cost Unmanned Underwater Vehicles ( UUV) built by the Mechatronics and Dynamic Modelling Laboratory ( MDM Lab) of the University of Florence. This vehicle is named FeelHippo, and it is an Autonomous Underwater Vehicle ( AUV) purposely developed to participate to the 2013 edition of the Student Autonomous Underwater Vehicle Challenge-Europe ( SAUC-e, http://sauc-europe.org/) organized by the NATO-STO Centre for Maritime Research and Experimentation ( CMRE), La Spezia, Italy. SAUC-e 2013 has been a good test field for the preliminary testing of the AUV capabilities and FeelHippo ranked third in the competition. In the paper some experimental results related to the development of a low-cost vehicle localization system, suitable inside an environment a priori known, are given and discussed.

Object of this work is the design and the development of the prototype of an innovative wearable mechatronics device able to increase the safety of divers. In particular the proposed system briefly called SARIS is a patented electronic device pluggable on standard over pressure valves of scuba jackets aimed at detecting the occurrence of too fast, possibly uncontrolled, ascents of the diver. In that case, it opens automatically the jacket’s overpressure valves for reducing its volume and stopping the ascent. In particular authors starting from the original specifications of Applicon SRL, the owner of the patent and customer of the application, developed original design criteria and successfully tested a working prototype of the device. In this work the design process of the innovative system are deeply explained and commented