On the Existence of Static Equilibria of a Cable-Suspended Load with Non-stopping Flying Carriers

This work answers positively the question whether non-stop flights are possible for maintaining constant the pose of cable-suspended objects. Such a counterintuitive answer paves the way for a paradigm shift where energetically efficient fixed-wing flying carriers can replace the inefficient multirotor carriers that have been used so far in precise cooperative cable-suspended aerial manipulation.First, we show that one or two flying carriers alone cannot perform non-stop flights while maintaining a constant pose of the suspended object. Instead, we prove that three flying carriers can achieve this task provided that the orientation of the load at the equilibrium is such that the components of the cable forces that balance the external force (typically gravity) do not belong to the plane of the cable anchoring points on the load. Numerical tests are presented in support of the analytical results

Mapping the First World War Forgotten Material Heritage: A Multi-proxy and GIS-based Proposal for the Trentino Alps

[EN] The material remains of the First World War field-battles are gradually disappearing, especially in marginal mountain areas, due to negligence and changes in land coverage. The paper presents the first stage of an ongoing project, devoted to identifying the forgotten material features of war landscapes on the Trentino Alps, using a wide range of historical sources, such as cartography, aerial and ground photos, textual descriptions and field surveys. The case study chosen to test the methodology is a small area of the municipality of Trambileno, in the south of the Province of Trento. Different data from different sources are integrated in a GIS platform, in order to safeguard the memory and the location of cultural heritage, as well as to support future enhancement plans.Dai Prà, E.; Gabellieri, N. (2020). Mapping the First World War Forgotten Material Heritage: A Multi-proxy and GIS-based Proposal for the Trentino Alps. Editorial Universitat Politècnica de València. 883-890. https://doi.org/10.4995/FORTMED2020.2020.11397OCS88389

Per una geostoria delle attivit\ue0 estrattive di Carrara: la cartografia digitale delle Cave de\u2019 Marmi descritte all\u2019impianto del Nuovo Catasto Estense (1821-1824).

L'idea di questo contributo nasce dal ritrovamento presso l'Archivio di Stato di Massa di una serie di registri e carte \u2013 estratto del Catasto Estense (1820-1824) \u2013 in cui sono elencate le cave di marmo esistenti nel territorio dello Stato di Carrara. Questi registri, a cui \ue8 allegato un apparato cartografico realizzato alla stessa scala dei fogli mappali (1:2000 o 1:4000), riportano varie informazioni sullo stato di attivit\ue0, i proprietari e la qualit\ue0 del marmo in quattro comunelli del carrarese sia alla data d\u2019impianto del Catasto sia per i secoli precedenti alla rilevazione fiscale. La prima parte dell\u2019articolo presenta quindi il contesto normativo ed economico dello Stato di Carrara nel XIX secolo, per illustrare le motivazioni e le modalit\ue0 di produzione della fonte. La seconda parte \ue8 invece dedicata all\u2019analisi sincronica della \u201cmetafonte\u201d elaborata vettorializzando le particelle catastali e trascrivendo le informazioni dei registri tramite applicativi GIS; la cartografia prodotta restituisce la struttura della propriet\ue0, lo stato e la qualit\ue0 delle cave al 1820-24. Questo lavoro di ricostruzione basato su fonti storiche si configura come un primo passo utile allo studio paesaggistico e geografico delle attivit\ue0 estrattive sulle Alpi Apuane. L\u2019incrocio con i dati odierni, in elaborazione presso il Centro di GeoTecnologie dell\u2019Universit\ue0 di Siena, consentir\ue0 in futuro un confronto diacronico e una mappatura dell\u2019ampliamento delle cave negli ultimi due secoli.The present work is inspired by the discovery in the Archivio di Stato di Massa of some registries \u2013 part of the Catasto Estense (1820-1824) \u2013 which listed the Carrara State marble quarries. The registries, as well as the linked maps (scale 1:2000 or 1:4000), provides data about the condition, the possession and the variety of the quarries, both for the 1820 and for the 1751 appraisal. The source data cover four comunelli (hamlets) of Carrara territory. The first part of the article presents the institutional, regulatory and economic context of the Carrara State in the XIX Century, in order to shows motivations and modality of the sources production. Cadastral maps have been vectorialized and registries data have been transcribed and linked with the map in order to create an integrated geo-database using a GIS software. The second part deals with the analysis of this \u201cmetasource\u201d; the geodatabase and the cartography shows the possession structure, the quarries condition and the marble varieties in the 1820-24. This work represents a first step for landscape and historical geography studies of the quarry activities in the Apuane Alps. The comparison with the currient quarries maps, actually in elaboration by the Centro di Tecnologie of the University of Siena, will allows a diachronic analysis of landscape and possession changes in the last two centuries

Force-based Pose Regulation of a Cable-Suspended Load Using UAVs with Force Bias

International audienceThis work studies how force measurement/estimation biases affect the force-based cooperative manipulation of a beam-like load suspended with cables by two aerial robots. Indeed, force biases are especially relevant in a force-based manipulation scenario in which direct communication is not relied upon. First, we compute the equilibrium configurations of the system. Then, we show that inducing an internal force in the load augments the robustness of the load attitude error and its sensitivity to force-bias variations. Eventually, we propose a method for zeroing the load position error. The results are validated through numerical simulations and experiments

Modelling, Analysis and Control of OmniMorph: an Omnidirectional Morphing Multi-rotor UAV

This paper introduces for the first time the design, modelling, and control of a novel morphing multi-rotor Unmanned Aerial Vehicle (UAV) that we call the OmniMorph. The morphing ability allows the selection of the configuration that optimizes energy consumption while ensuring the needed maneuverability for the required task. The most energy-efficient uni-directional thrust (UDT) configuration can be used, e.g., during standard point-to-point displacements. Fully-actuated (FA) and omnidirectional (OD) configurations can be instead used for full pose tracking, such as, e.g., constant attitude horizontal motions and full rotations on the spot, and for full wrench 6D interaction control and 6D disturbance rejection. Morphing is obtained using a single servomotor, allowing possible minimization of weight, costs, and maintenance complexity. The actuation properties are studied, and an optimal controller that compromises between performance and control effort is proposed and validated in realistic simulations

Riforma agraria, bonifica e territorializzazione nelle Maremme toscane; alcuni spunti dall’archivio storico dell’Ente Maremma (1951-1965)

This paper deals with the topic of the Agrarian reform in southern Tuscany (1951-1965) using a territorial history approach; that is, it focuses on the reshaping of local society, economy and environments due to a national process as the Reform, it highlights the importance of discontinuities in territorialisation trends. Methodologically, the use of a local approach allows a better understanding and depiction of social actors and past practices, avoiding the decontextualisation of places and historical processes. The first section of the paper presents some discussion topics emerging from an analysis of the historical archives of the public body competent for the Reform in Maremma; the second section presents a first hypothesis for a history of the Agrarian reform as a moment of requalification of environmental resources – changes in ownership, access and use – using water as a case study.  Finally, the paper highlights how the relations among social actors, environmental resources and territorial projects have been – and still are – a key point in territorialisation processes

Chapter Il filo da riannodare: Massimo Quaini, una letteratura per la geografia e una geografia per la letteratura

With regard to the relationship between literary works and geographical studies, Massimo Quaini’s interest consolidated into a heuristic imprint whose originality has not yet been adequately enlightened. Through the analysis of his essays, the paper identifies some clues of his thought: methodologically, the need for a critical approach of ‘archeology of knowledge and sources’ to the writer’s profile; teleologically, the identification of the geographical factors inside the works as a tool for territorial enhancement; epistemologically, the use of literary topoi and metaphors as an interpretive key – together with the geographical-historical analysis – of the historical and current territorial dynamics

The Archeology of Woodland Ecology: Reconstructing Past Woodmanship Practices of Wooded Pasture Systems in Italy

Recently, the woodmanship practices and localized naturalistic knowledge have been acquired as indispensable for the European forest heritage conservation as well as for restoration of individual woodland landscapes. Minor importance has been given to the historical approach, both in the study of the local resources ecology and of the local societal context. Using the results of a series of case studies—applied to the knowledge and planning of sites that host present (or have hosted in past) wooded pasture systems and their environmental legacy—the chapter shows the interest of the environmental resource archeology (ERA): a “multisource approach” in reconstructing past management systems practices and underpinned lore. ERA is inspired by the method and sources of the English historical ecology and topographical history employing both archives and field evidences (palynology, anthracology, etc.)

An Experimentally Validated Model of the Propeller Force Accounting for Cross Influences on Multi-Rotor Aerial Systems

In this paper, we propose a model for the thrust coefficient of propellers that can take into account cross-influence between adjacent propellers. The aerodynamic interaction between propellers in multirotor aerial vehicles reduces the thrust they can produce. The influence between propellers depends on their relative positioning and orientation, which are taken into account by the proposed model. It is validated on measurements collected by a force sensor mounted on a propeller for different configurations of the adjacent propellers in a support structure. In this work, we focus on configurations with small relative orientations. Results show that the proposed model outperforms the traditional constant model in terms of thrust prediction on the data we collected, and it performs better than other models with fewer parameters, being the only one with less than 10% maximum percentage error