Compensation of position errors in passivity based teleoperation over packet switched communication networks

Because of the use of scattering based communication channels, passivity based telemanipulation systems can be subject to a steady state position error between master and slave robots. In this paper, we consider the case in which the passive master and slave sides communicate through a packet switched communication channel (e.g. Internet) and we provide a modification of the slave impedance controller for compensating the steady state position error arising in free motion because of packets loss

Global bifurcation of homoclinic solutions of hamiltonian systems

We provide global bifurcation results for a class of nonlinear hamiltonian systemsComment: 25 page

Il territorio di Divjakë, paesaggi in competizione

La regione costiera di Divjakë, in Albania è da tempo soggetta ad una crescente domanda di sviluppo territoriale ed economico. Diverse immagini di trasformazione e altrettanti progetti di sfruttamento turistico di questa costa fragile e dinamica sono posti attualmente in competizione. Il programma di cooperazione URBAN LAB , intrapreso recentemente ha come obiettivo principale la costruzione di una alternativa realistica e innovativa ai modelli dominanti di turismo costiero, in gran parte dipendenti dagli investimenti esteri. Obiettivo generale di Urban Lab è favorire lo sviluppo territoriale, ambientale e turistico delle aree costiere lagunari. Nella regione di Divjakë, ciò si traduce in una serie di azioni volte a promuovere lo sviluppo socio-economico, attraverso un modello partecipato di gestione e promozione delle risorse locali: un laboratorio urbano, con la partecipazione attiva dei giovani, della società civile e delle istituzioni locali. L’approccio innovativo di questo programma di cooperazione consiste nella stretta associazione di un progetto di riscrittura del paesaggio, con un progetto di formazione rivolto alle popolazioni locali. Il programma di lavoro recentemente inaugurato, mentre costruisce una nuova immagine del territorio, propone al contempo strumenti di progetto in grado di porsi in una posizione intermedia tra l’ascolto dei bisogni e delle aspettative della società e la ricostruzione di una pratica di gestione territoriale legittima e condivisa.In recent decades, Divjake region, on Albania Mediterranean coast, has been subject to an increasing demand for local economic development. Different transformation perspectives and contrasting tourism development strategies are competing on this fragile but dynamic region. The cooperation program Urban Lab, recently undertaken, aims at the provision of a realistic and innovative strategy as an alternative to mainstream programs of mass-tourism seaside development, which are largely dependent on international investments. As a general objective, Urban Lab, promotes environment protection and tourism development on the coast and in the lagoon area. A range of actions trigger innovation in socioeconomic development through a participative planning process while reinforcing local resources. In this perspective, an urban laboratory with the active involvement of young people, civil society and institutions is foreseen. The innovative approach entails the association between a territorial project, reframing local landscape, and an educational program addressed to local residents. The research program, thus, positions itself at an intermediate level between the reception of society needs or expectations and the reconstruction of a legitimate and participated planning practice

Port-contact systems in bilateral telemanipulation

In this paper we develop one of the first control applications of the recently proposed port-contact framework. We show how it is possible to model and control a bilateral telemanipulation system using port-contact systems and we develop a port-contact impedance controller that allows to impose a desired interactive behavior and a zero steady state position error during contact tasks

Participatory design, beyond the local

This workshop aims at stimulating and opening a debate around the capacity of Participatory Design (PD) and other co-design approaches to deliver outcomes and methodologies that can have an impact and value for reuse well beyond the local context in which they were originally developed. This will be achieved by stimulating the submission of position papers by researchers from the PD community and beyond.These papers will be discussed during the workshop in order to identify challenges, obstacles but also potentials for scaling up PD processes and results from the local to the global.</p

Communication Through Motion: Legibility of Multi-Robot Systems

The interaction between a user and a multi-robot system in a shared environment is a relatively uncharted topic. But, as these types of systems will increase in the future years, an efficient way of communication is necessary. To this aim, it is interesting to discover if a multi-robot system can communicate its intentions exploiting only some motion-variables, which are characteristics of the motion of the robots. This study is about the legibility of a multi-robot system: In particular, we focus on the influence of these motion-variables on the legibility of more than one group of robots that move in a shared environment with the user. These motion-variables are: Trajectory, dispersion and stiffness. They are generally used to define the motion of a group of mobile robots. Trajectory and dispersion were found relevant for the correctness of the communication between the user and the multi-robot system, while stiffness was found relevant for the rapidity of communication. The analysis of the influence of the motion-variables was carried out with an ANOVA (analysis of variance) based on a series of data coming from an experimental campaign conducted in a virtual reality set-up

Observation and Spectroscopy of a Two-Electron Wigner Molecule in an Ultra-Clean Carbon Nanotube

Coulomb interactions can have a decisive effect on the ground state of electronic systems. The simplest system in which interactions can play an interesting role is that of two electrons on a string. In the presence of strong interactions the two electrons are predicted to form a Wigner molecule, separating to the ends of the string due to their mutual repulsion. This spatial structure is believed to be clearly imprinted on the energy spectrum, yet to date a direct measurement of such a spectrum in a controllable one-dimensional setting is still missing. Here we use an ultra-clean suspended carbon nanotube to realize this system in a tunable potential. Using tunneling spectroscopy we measure the excitation spectra of two interacting carriers, electrons or holes, and identify seven low-energy states characterized by their spin and isospin quantum numbers. These states fall into two multiplets according to their exchange symmetries. The formation of a strongly-interacting Wigner molecule is evident from the small energy splitting measured between the two multiplets, that is quenched by an order of magnitude compared to the non-interacting value. Our ability to tune the two-electron state in space and to study it for both electrons and holes provides an unambiguous demonstration of the fundamental Wigner molecule state.Comment: SP and FK contributed equally to this wor

Formation and Acceleration of Uniformly-Filled Ellipsoidal Electron Bunches Obtained via Space-Charge-Driven Expansion from a Cesium-Telluride Photocathode

We report the experimental generation, acceleration and characterization of a uniformly-filled electron bunch obtained via space-charge-driven expansion (often referred to as "blow-out regime") in an L-band (1.3-GHz) radiofrequency photoinjector. The beam is photoemitted from a Cesium-Telluride semiconductor photocathode using a short ($<200$ fs) ultraviolet laser pulse. The produced electron bunches are characterized with conventional diagnostics and the signatures of their ellipsoidal character is observed. We especially demonstrate the production of ellipsoidal bunches with charges up to $\sim0.5$ nC corresponding to a $\sim20$-fold increase compared to previous experiments with metallic photocathodes.Comment: 9, pages, 13 figure