Development of a Hybrid Simulator for Underwater Vehicles with Manipulators

This article describes a hybrid simulation approach meant to facilitate the realization of a simulator for underwater vehicles with one or more manipulators capable of simulating the interaction of the vehicle with objects and structures of the environment. The hybrid simulation approach is first described and motivated analytically, then an analysis of simulation accuracy is proposed, where, in particular, the implications of added mass simulation are discussed. Then, a possible implementation of the proposed architecture is shown, where a robotic simulator of articulated bodies, capable of stable and accurate simulation of contact forces, although unfit to simulate any serious hydrodynamic model, is tightly interfaced with a general purpose dynamic systems simulator that is used to simulate the hydrodynamic forces, the vehicle guidance, navigation, and control system, and also a man-machine interface. Software details and the technicalities needed to interface the two simulators are also briefly presented. Finally, the results of the simulation of three operational scenarios are proposed as qualitative assessment of the simulator capabilities

Parsimonious Cooperative Distributed MPC for Tracking Piece-Wise Constant Setpoints

Distributed Model Predictive Control refers to a class of predictive control architectures in which a number of local controllers manipulate a subset of inputs to regulate a subset of outputs composing the overall system. These controllers may cooperate to find an optimal control sequence that minimizes a global cost function, as in the case of Cooperative Distributed Model Predictive Control (CD-MPC). In this paper two linear CD-MPC algorithms for tracking are proposed. The aim of these controllers is to drive the outputs of the overall system to any admissible piece-wise constant set-point, satisfying input and state constraints. However, in the available literature this result is achieved by using a set of centralized variables that keep track of the global state of the system. In contrast, we develop novel CD-MPC approaches for tracking that rely on “as local as possible” information instead of the plant-wide information flow. These new control strategies reduce the required communication overhead, local computational demands, and are more scalable than CD-MPC algorithms available in the literature. We illustrate the main characteristics and benefits of the proposed approaches by means of a multiple evaporator process example

Development of the Guidance Navigation and Control System of the Folaga AUV for Autonomous Acoustic Surveys in the WiMUST Project

This paper deals with the development of the Guidance Navigation and Control (GNC) system of the Autonomous Underwater Vehicle (AUV) used for acoustic surveys in the WiMUST projects. By exploiting the fact that the vehicle hull has a modular structure, a specific payload module was realized containing a single board computer, two acoustic modems, the electronic boards for signal conditioning and data storage of seismic data, and the mechanical interface for the streamer, the array of hydrophones that constitutes the main mission payload. Then, by using the Robot Operating System (ROS) the mission control system was implemented in the single board computer inside the additional payload segment. Motion control for the AUV was realized designing controllers for surge speed, heading and depth. Design of the depth controller represented one of the major challenges mainly because towing the streamer heavily affects the vehicle dynamics when underwater. Thus, a specific fuzzy-PID control system was implemented and tested. This one, together with the surge speed and the heading controller are discussed in this paper. Finally, selected experimental results from sea trials are discussed to prove the effectiveness of the presented GNC system

A Visual-Haptic Display for Human and Autonomous Systems Integration

This paper introduces a novel concept of visual-haptic display for situational awareness improvement for crowded and low altitude airspace situations. It presents first the visual augmentation display that constitutes of Virtual Fences delimiting no-fly zones, and a specific threei-dimensional highlight graphics that enhances visibility of other autonomous (or not) agents in the area. Then it presents the shared control paradigm and the Haptic Force generation mechanism, based on a Proportional-Derivative-like controller applied to repulsive forces generated by the Virtual Fences and other UAVs. Simulations with 26 pilots were performed in a photo-realistic synthetic environment showing that the Visual-haptic Display outperforms the Visual Display only at helping the pilot keeping distance from no- fly zones and other vehicles

Increasing prevalence of multiple sclerosis in Tuscany, Italy

Background and rationale: An increase of prevalence and incidence of multiple sclerosis (MS) has been reported in several countries, especially taking into account a long-term evaluation. This increasing trend often reflects improved case identification and ascertainment due to the refinement of diagnostic criteria. The aim of this study was to update the prevalence rate of MS in Tuscany (central Italy) as of 2017, and to assess if there has been an increasing trend of prevalence in this Region considering a short period of analysis, from 2014 to 2017. Methods: To capture prevalent cases, a case-finding algorithm based on administrative data, previously created and validated, was used. As data sources, we considered hospital discharge records, drug-dispensing records, disease-specific exemptions from copayment to health care, home and residential long-term care, and inhabitant registry. Results: As of January 1, 2017, 7809 cases were identified, of which 69.4% were females and 30.6% were males. Considering temporal variation, an increasing trend was observed, with standardized rates rising from 189.2 in 2014 to 208.7 per 100,000 in 2017. Conclusions: Results confirm that prevalence increases every year, probably mainly due to the difference between incidence and mortality, resulting in an increasing trend. Moreover, administrative data may accurately identify MS patients in a routinary way and monitor this cohort along disease care pathways

AUV navigation, guidance, and control for geoseismic data acquisition

none9noThis chapter describes the main challenges, and the corresponding solutions, encountered during the development of the guidance, navigation, and control (GNC) systems for the autonomous underwater vehicles (AUVs) and the autonomous surface vehicles (ASVs) involved in the Widely scalable Mobile Underwater Sonar Technology (WiMUST) projectmixedLorenzo Pollini, Gianluca Antonelli, Filippo Arrichiello, Andrea Caiti, Giuseppe Casalino, Daniela De Palma, Giovanni Indiveri, Matteo Razzanelli, Enrico SimettiPollini, Lorenzo; Antonelli, Gianluca; Arrichiello, Filippo; Caiti, Andrea; Casalino, Giuseppe; De Palma, Daniela; Indiveri, Giovanni; Razzanelli, Matteo; Simetti, Enric

Urban-rural differences in hospitalisation rates among elderly patients in two long-term care settings in Tuscany, Italy

Context Patients who are in nursing homes or homes in community-based settings that belongs to the category of elderly in long-term care (LTC) often have complex needs that require different kinds of support because of their functional and cognitive limitations, as well as their need for medical care for acute and chronic conditions. Our aim was to see if there are any differences between hospitalizations in high and low density areas for the patients who are in an LTC program, in nursing homes or in home care. Methods This study is an ecological study using data sources from the Tuscany region during the period 2012-2013. In our study we measured the percentage of hospitalization. We measured the use of hospitalization by the dependent elderly in home care and nursing homes, taking into account that they have complex needs. Our analysis has drawn on administrative health data for those aged 65 and over with complex needs who are in an individual planning program in Tuscany, Italy. Hospital discharge data were obtained from the Agenzia regionale di sanita della Toscana (ARS).The denominator was the elderly in home care and residential care, during the given period (1000 personyears). Levels of rurality were measured using OECD REGIONAL TYPOLOGY, 2010, which is based on the criteria of population density and size of the urban centres located within a region. Descriptive and inferential statistics were performed. Results Our sample size was 13,869 patients in the Tuscany region who were in the LTC program during the period 20122013. The median rate of hospitalization in low density areas was 49.33% (per 100 person-years) for the elderly in home care, and 51.08% (per 100 person-years) from more densely populated districts. For elderly people in residential care, the median rate of hospitalization was 42.48% (per 100 person-years) in low density areas and 47.36% (per 100 person-years) in high density districts. The p-values for low vs high density areas are 0.120 for the first indicator, and 0.358 for the second indicator. Discussion Our findings show that there are not significant differences of health disparities between elderly in Long term care program in rural and urban areas, which may derive from free access to care and more healthcare programs in rural areas. Although certain disparities still exit, like a higher hospitalization rate in more densely population districts, especially in home care, the health care system has effectively reduced rural-urban disparities when it comes to the elderly with complex needs. Further steps are needed to be performed in order to delve this preliminary evidence