Bilateral Teleoperation of Groups of Mobile Robots With Time-Varying Topology

Franchi, A.,Secchi, C.,Hyoung Il Son,Bulthoff, H. H.,Giordano, P. R. IEEE 2012 IEEE transactions on robotics Vol.28 No.5

<P>In this paper, a novel decentralized control strategy for bilaterally teleoperating heterogeneous groups of mobile robots from different domains (aerial, ground, marine, and underwater) is proposed. By using a decentralized control architecture, the group of robots, which is treated as the slave side, is made able to navigate in a cluttered environment while avoiding obstacles, interrobot collisions, and following the human motion commands. Simultaneously, the human operator acting on the master side is provided with a suitable force feedback informative of the group response and of the interaction with the surrounding environment. Using passivity-based techniques, we allow the behavior of the group to be as flexible as possible with arbitrary split and join events (e.g., due to interrobot visibility/packet losses or specific task requirements) while guaranteeing the stability of the system. We provide a rigorous analysis of the system stability and steady-state characteristics and validate performance through human/hardware-in-the-loop simulations by considering a heterogeneous fleet of unmanned aerial vehicles (UAVs) and unmanned ground vehicles as a case study. Finally, we also provide an experimental validation with four quadrotor UAVs.</P>

Shared Control : Balancing Autonomy and Human Assistance with a Group of Quadrotor UAVs

Franchi, A.,Secchi, C.,Ryll, M.,Bulthoff, H. H.,Giordano, P. R. IEEE 2012 IEEE robotics & automation magazine Vol.19 No.3

<P>Robustness and flexibility constitute the main advantages of multiple-robot systems with respect to single-robot ones as per the recent literature. The use of multiple unmanned aerial vehicles (UAVs) combines these benefits with the agility and pervasiveness of aerial platforms [1], [2]. The degree of autonomy of the multi-UAV system should be tuned according to the specificities of the situation under consideration. For regular missions, fully autonomous UAV systems are often appropriate, but, in general, the use of semiautonomous groups of UAVs, supervised or partially controlled by one or more human operators, is the only viable solution to deal with the complexity and unpredictability of real-world scenarios as in, e.g., the case of search and rescue missions or exploration of large/cluttered environments [3]. In addition, the human presence is also mandatory for taking the responsibility of critical decisions in high-risk situations [4].</P>

Modeling and Control of UAV Bearing Formations with Bilateral High-level Steering

Franchi, Antonio,Masone, Carlo,Grabe, Volker,Ryll, Markus,Bü,lthoff, Heinrich H,Giordano, Paolo Robuffo SAGE Publications 2012 The International journal of robotics research Vol.31 No.12

Oltre la poesia: il Petrarca come precursore della complessita psicologica moderna

( Francesco Piero Franchi ) 한국이탈리아어문학회(구-한국이어이문학회) 2004 이탈리아어문학 Vol.15 No.-

Semiautonomous Haptic Teleoperation Control Architecture of Multiple Unmanned Aerial Vehicles

Dongjun Lee,Franchi, Antonio,Hyoung Il Son,ChangSu Ha,Bulthoff, Heinrich H.,Giordano, Paolo Robuffo IEEE 2013 IEEE/ASME transactions on mechatronics Vol.18 No.4

<P>We propose a novel semiautonomous haptic teleoperation control architecture for multiple unmanned aerial vehicles (UAVs), consisting of three control layers: 1) UAV control layer, where each UAV is abstracted by, and is controlled to follow the trajectory of, its own kinematic Cartesian virtual point (VP); 2) VP control layer, which modulates each VP's motion according to the teleoperation commands and local artificial potentials (for VP-VP/VP-obstacle collision avoidance and VP-VP connectivity preservation); and 3) teleoperation layer, through which a single remote human user can command all (or some) of the VPs' velocity while haptically perceiving the state of all (or some) of the UAVs and obstacles. Master passivity/slave stability and some asymptotic performance measures are proved. Experimental results using four custom-built quadrotor-type UAVs are also presented to illustrate the theory.</P>

Decentralized rigidity maintenance control with range measurements for multi-robot systems

Zelazo, Daniel,Franchi, Antonio,Bü,lthoff, Heinrich H.,Robuffo Giordano, Paolo SAGE Publications 2015 The International journal of robotics research Vol.34 No.1

<P>This work proposes a fully decentralized strategy for maintaining the formation rigidity of a multi-robot system using only range measurements, while still allowing the graph topology to change freely over time. In this direction, a first contribution of this work is an extension of rigidity theory to <I>weighted frameworks</I> and the <I>rigidity eigenvalue</I>, which when positive ensures the infinitesimal rigidity of the framework. We then propose a distributed algorithm for estimating a common relative position reference frame amongst a team of robots with only range measurements in addition to one agent endowed with the capability of measuring the bearing to two other agents. This first estimation step is embedded into a subsequent distributed algorithm for estimating the rigidity eigenvalue associated with the weighted framework. The estimate of the rigidity eigenvalue is finally used to generate a local control action for each agent that both maintains the rigidity property and enforces additional constraints such as collision avoidance and sensing/communication range limits and occlusions. As an additional feature of our approach, the communication and sensing links among the robots are also left free to change over time while preserving rigidity of the whole framework. The proposed scheme is then experimentally validated with a robotic testbed consisting of six quadrotor unmanned aerial vehicles operating in a cluttered environment.</P>

A passivity-based decentralized strategy for generalized connectivity maintenance

Robuffo Giordano, Paolo,Franchi, Antonio,Seccos, Christian,Bü,lthoff, Heinrich H SAGE Publications 2013 The International journal of robotics research Vol.32 No.3

<P>The design of decentralized controllers coping with the typical constraints on the inter-robot sensing/communication capabilities represents a promising direction in multi-robot research thanks to the inherent scalability and fault tolerance of these approaches. In these cases, <I>connectivity</I> of the underlying interaction graph plays a fundamental role: it represents a necessary condition for allowing a group or robots to achieve a common task by resorting to only local information. The goal of this paper is to present a novel decentralized strategy able to enforce <I>connectivity maintenance</I> for a group of robots in a flexible way, that is, by granting large freedom to the group internal configuration so as to allow establishment/deletion of interaction links at anytime as long as global connectivity is preserved. A peculiar feature of our approach is that we are able to embed into a <I>unique connectivity preserving action</I> a large number of constraints and requirements for the group: (i) the presence of specific inter-robot sensing/communication models; (ii) group requirements such as formation control; and (iii) individual requirements such as collision avoidance. This is achieved by defining a suitable global potential function of the second smallest eigenvalue λ<SUB>2</SUB> of the graph Laplacian, and by computing, in a decentralized way, a gradient-like controller built on top of this potential. Simulation results obtained with a group of quadrotor unmanned aerial vehicles (UAVs) and unmanned ground vehicles, and experimental results obtained with four quadrotor UAVs, are finally presented to thoroughly illustrate the features of our approach on a concrete case study.</P>

Diagnostic value of HSP70, glypican 3, and glutamine synthetase in hepatocellular nodules in cirrhosis

Di Tommaso, Luca,Franchi, Giada,Park, Young Nyun,Fiamengo, Barbara,Destro, Annarita,Morenghi, Emanuela,Montorsi, Marco,Torzilli, Guido,Tommasini, Maurizio,Terracciano, Luigi,Tornillo, Luigi,Vecchione, Wiley Subscription Services, Inc., A Wiley Company 2007 Hepatology Vol.45 No.3

<P>Hepatocellular nodules in cirrhosis include regenerative (large regenerative, LRN) and dysplastic (low and high grade, LGDN and HGDN) nodules, early and grade 1 HCC (eHCC-G1), and overt HCC. The differential diagnosis may be particularly difficult when lesions such as HGDN and eHCC-G1 are involved. We investigated the diagnostic yield of a panel of 3 putative markers of hepatocellular malignancy such as HSP70, glypican 3 (GPC3), and glutamine synthetase (GS). We selected 52 surgically removed nonmalignant nodules (15 LRNs, 15 LGDNs, 22 HGDNs) and 53 HCCs (10 early, 22 grade 1, and 21 grade 2-3) and immunostained them for HSP70, GPC3, and GS. The sensitivity and specificity of the individual markers for the detection of eHCC-G1 were 59% and 86% for GS, 69% and 91% for GPC3, and 78% and 95% for HSP70. We identified 2 main phenotypes: (1) all negative, seen in 100% LRN and LGDN, 73% HGDN and 3% eHCC-G1; (2) all positive, a feature detected in less than half the eHCC-G1. Using a 3-marker panel, when at least 2 of them, regardless which, were positive, the sensitivity and specificity for the detection of eHCC-G1 were respectively 72% and 100%; the most sensitive combination was HSP70+/GPC3+ (59%) when a 2-marker panel was used. Conclusion: The adopted panel of 3 markers is very helpful in distinguishing eHCC-G1 from dysplastic nodules arising in cirrhosis. (HEPATOLOGY 2007;45:725–734.)</P>

The Europlanet Research Infrastructure: Planetary Field Analogues

Barbara Cavalazzi,Fulvio Franchi,Viggo Marteinsson,Keld Rasmussen,Jon Merrison,Felipe Gomez,Fernando Gomez,Miruts Hagos,Yang Liu,Anita Heward,Nigel Mason,Gareth Davies 대한지질학회 2021 대한지질학회 학술대회 Vol.2021 No.10

The Europlanet 2024 Research Infrastructure provides access to well characterised field sites that represent the most realistic terrestrial geological-geomorphological analogues for volcanic, dry-and humid-cold, hot, highly saline and metalliferous and impact conditions for studies in support of current and forthcoming missions to Mars, the Moon and the icy moons of Jupiter. Europlanet 2024 RI offers free ‘transnational access’ to seven diverse PFA sites around the world that have been comprehensively characterised. This enables researchers to undertake multi-disciplinary research programmes in support of planetary missions allowing to: • quantify the complex (bio) geo-chemical feed-back processes that control planetary evolution: • develop (quantified) models to explain observations of planets in our Solar System from rovers: orbiting instruments, and ground-based observations and (potentially) interpret data from exoplanets. • study the processes that influence the strategy and adaption of life to extreme conditions: • test our ability to detect unambiguously records of past or present biological activity: • test new instrumentation and operational systems for future planetary space missions under fully operational conditions: Iceland offers a multitude of different environments, including glacial and sub-glacial environments, lava fields of different ages, volcanic areas and active hydrothermal systems. The Greenland Kangerlussuaq field site provides excellent access to a glacial ice sheet and regions with permafrost, glacial sediment deposits and also glacial run-off which meets the ocean. The Makgadikgadi pans of Botswana represent the largest inland evaporitic basin in the world. The pans provide different environments that vary from the playa lake with the ephemeral spring to a fossil dunes field. The unique nature of Rio Tinto, Spain, is caused by rock-water-biology interactions that produces a river with a pH of ~ 2.3 over a length of ~ 100 km. Unfortunately, due to political instability, the acidic hydrothermal and highly saline environments of the Danakil Depression in Ethiopia are currently inaccessible. However, two new field areas will be made available for Europlanet TA access in subsequent calls: i) the Qaidam Basin in the north of the Tibetan Plateau includes Mars-analog lacustrine environments and ii) the Puna, Patagonia and Tierra del Fuego regions in Argentina provide access to cold and wet-cold, extreme glacial and lacustrine environments. The presentation will briefly review the characteristics of the Planetary Field Analogues. More details are available at: https://www.europlanet-society.org/europlanet-2024-ri/ta1-pfa/

Protective Effect of Allium neapolitanum Cyr. Versus Allium sativum L. on Acute Ethanol-Induced Oxidative Stress in Rat Liver

Cristina Nencini,Gian Gabriele Franchi,Federica Cavallo,Lucia Micheli 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.2

This study investigated the protective effect of Allium neapolitanum Cyr., a spontaneous species of the Italian flora, compared with garlic (Allium sativum L.) on liver injury induced by ethanol in rats. Male albino Wistar rats were orally treated with fresh Allium homogenates (leaves or bulbs, 250mg/kg) daily for 5 days, whereas controls received vehicle only. At the end of the experimental 5-day period, the animals received an acute ethanol dose (6mL/kg, i.p.) 2 hours before the last Allium administration and were sacrificed 6 hours after ethanol administration. The activities of catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GR) and the levels of malondialdehyde (MDA), ascorbic acid (AA), and reduced (GSH) and oxidized glutathione in liver tissue were determined. Administration of both Allium species for 5 days (leaves or bulbs) led to no statistical variation of nonenzymatic parameters versus the control group; otherwise Allium treatment caused an increase of GSH and AA levels compared with the ethanol group and a diminution of MDA levels, showing in addition that A. neapolitanum bulb had the best protective effect. Regarding to enzymatic parameters, GR and CAT activities were enhanced significantly compared with the ethanol group, whereas SOD activity showed a trend different from other parameters estimated. However, the treatment with both Allium species followed by acute ethanol administration reestablished the nonenzymatic parameters similar to control values and enhanced the activities of the enzymes measured. These results suggest that fresh Allium homogenates (leaves or bulbs) possess antioxidant properties and provide protection against ethanol-induced liver injury.