Manipulability Optimization of a Rehabilitative Collaborative Robotic System

The use of collaborative robots (or cobots) in rehabilitation therapies is aimed at assisting and shortening the patient's recovery after neurological injuries. Cobots are inherently safe when interacting with humans and can be programmed in different working modalities based on the patient's needs and the level of the injury. This study presents a design optimization of a robotic system for upper limb rehabilitation based on the manipulability ellipsoid method. The human-robot system is modeled as a closed kinematic chain in which the human hand grasps a handle attached to the robot's end effector. The manipulability ellipsoids are determined for both the human and the robotic arm and compared by calculating an index that quantifies the alignment of the principal axes. The optimal position of the robot base with respect to the patient is identified by a first global optimization and by a further local refinement, seeking the best alignment of the manipulability ellipsoids in a series of points uniformly distributed within the shared workspace

La costruzione ideologica dell’identità martiriale: i Quaranta martiri di Sebaste, Teodoro di Amasea e Stefano Protomartire negli encomi di Gregorio di Nissa

L’esaltazione del martirio si sviluppa parallelamente alla costruzione ideologica dell’identità cristiana, attraverso la teorizzazione del sacrificio come pilastro del Cristianesimo primitivo. La morte cruenta rivela, nel discepolato cristiano, il vincolo indissolubile esistente tra vita e identità religiosa. Come si evince dagli encomi di Gregorio di Nissa, esiste una relazione intrinseca tra la letteratura martiriale e il forgiarsi di un’identità cristiana. Per il vescovo di Nissa, il modello di “identità martiriale cristiana” è il protomartire Stefano: nel suo encomio, citando Paolo (I Cor 4,9), afferma: “Stefano è divenuto spettacolo per il mondo, gli angeli e gli uomini” (In Sanctum Stephanum, I, 76,3).The glorification of martyrdom runs parallel to the ideological construction of the Christian identity, through the theorization of sacrifice as a pillar of Early Christianity. Bloody death reveals, in Christian discipleship, the unbreakable bond existing between life and religious identity. As can be seen from the encomia of Gregory of Nyssa, there is an intrinsic relationship between martyrdom literature and the forging of a Christian identity. As can be seen from the bishop of Nyssa’s encomia, the model of “Christian martyrdom identity” is the protomartyr Stephen: in his encomium, citing Paul (I Cor 4,9), he says: “Stephen has become a spectacle to the world, angels and men” (In Sanctum Stephanum, I, 76.3)

¿Biografía o hagiobiografía? : El De Vita Gregorii Thaumaturgi de Gregorio de Nisa

La Vida de Gregorio Taumaturgo, del obispo capadocio Gregorio de Nisa, constituye el prototipo de un nuevo género literario cristiano, la hagiobiografía. Perfilando a un santo como hagios, el objetivo del encomiasta es presentar el elogiado a los fieles como modelo de virtud, realzado por el relato de sus thaumata (prodigios). La biografía novelada de la vida y los milagros de Gregorio de Neocaesarea (conocido por la tradición posterior como Gregorio el Taumaturgo) pone de manifiesto la evidente deuda de la oratoria cristiana respecto a los recursos retóricos de la Segunda Sofística. Gregorio se convierte, por lo tanto, en un modelo de santo taumatúrgico, un arquetipo de hagios literario durante las épocas bizantina y medieval.The Life of Gregory the Wonder-worker, by the Cappadocian bishop Gregory of Nyssa, represents the prototype of a new Christian literary genre: the hagiobiography. By depicting a saint as hagios, the goal of the panegyrist is to present the object of praise to the faithful as a model of virtue, aggrandised by the story of his thaumata (wonders). The fictionalised biography of the life and miracles of Gregory of Neocaesarea (known by later tradition as Gregory Thaumaturgus), highlights the obvious debt of Christian oratory to the rhetorical resources of the Second Sophistic. Gregory becomes, therefore, a model of a wonder-working saint, an archetype of literary hagios during the Byzantine and medieval eras

Skopós and Akolouthía in the Commentary of the Songs of Songs of Gregory of Nyssa

L’ermeneutica nissena si basa essenzialmente su due categorie esegetiche quali lo σκοπός e la ἀκολουθία. Ambedue non costituiscono un’invenzione letteraria del padre cappadoce, bensì rappresentano un’eredità anteriore delle scuole filosofiche, in maggioranza stoiche e neoplatoniche. Questo studio prevede un’analisi letteraria di entrambi i concetti e della loro applicazione ermeneutica nell’esegesi al testo biblico del Cantico dei Cantici. Dallo studio condotto si evince pertanto l’influenza meridiana del patrimonio classico e delle sue risorse scientifiche nei trattati di Gregorio di Nissa e della letteratura cristiana.The hermeneutics of Gregory of Nyssa is essentially based on two exegetical categories: the σκοπός and the ἀκολουθία. Neither one constitutes a literary invention of the Cappadocian priest, but both represent an earlier legacy of the philosophical schools, mostly Stoic and Neo–Platonic. This study provides a literary analysis of both concepts and their hermeneutical application in the exegesis to the biblical text of the Song of Songs. Therefore, the study conducted shows the clear influence of the classical heritage, as well as its scientific resources, in the treatises of Gregory of Nyssa and in Christian literature.Humanidade

El encomio del protomártir Esteban de Gregorio de Nisa entre hagiografía y βασιλικὸς λόγος

La tradición hagiográfica transmitida e impulsada a partir del texto de los Hechos de los Apóstoles sobre el primer héroe del cristianismo primitivo, el protomártir Esteban, encuentra, en uno de los dos βασιλικοὶ λόγοι de Gregorio de Nisa (Gr. Nyss., Steph. I, ed. O Lendle, 1990, 97,4 - 105,21), una de sus más brillantes representaciones literarias. La hagiografía del santo se desarrolla siguiendo las normas del discurso imperial, teorizado en los dos tratados “Sobre los géneros epidícticos” atribuidos a Menandro el Rétor, en los cuales se hace hincapié en los τόποι ἐγκωμιαστικοί respecto al panegírico del personaje alabado. En la primera traducción al castellano, que presentamos a continuación, se pone un particular énfasis en esta innovación: el obispo de Nisa consigue transformar el relato neotestamentario en un discurso de fuertes matices propagandísticos, en el cual los aspectos más corrientes del personaje (patria, educación, actos) se convierten en virtudes y gestas de un arquetipo cristiano a seguir

Adaptive Obstacle Avoidance for a Class of Collaborative Robots

In a human–robot collaboration scenario, operator safety is the main problem and must be guaranteed under all conditions. Collision avoidance control techniques are essential to improve operator safety and robot flexibility by preventing impacts that can occur between the robot and humans or with objects inadvertently left within the operational workspace. On this basis, collision avoidance algorithms for moving obstacles are presented in this paper: inspired by algorithms already developed by the authors for planar manipulators, algorithms are adapted for the 6-DOF collaborative manipulators by Universal Robots, and some new contributions are introduced. First, in this work, the safety region wrapping each link of the manipulator assumes a cylindrical shape whose radius varies according to the speed of the colliding obstacle, so that dynamical obstacles are avoided with increased safety regions in order to reduce the risk, whereas fixed obstacles allow us to use smaller safety regions, facilitating the motion of the robot. In addition, three different modalities for the collision avoidance control law are proposed, which differ in the type of motion admitted for the perturbation of the end-effector: the general mode allows for a 6-DOF perturbation, but restrictions can be imposed on the orientation part of the avoidance motion using 4-DOF or 3-DOF modes. In order to demonstrate the effectiveness of the control strategy, simulations with dynamic and fixed obstacles are presented and discussed. Simulations are also used to estimate the required computational effort in order to verify the transferability to a real system

Human-Centered Design of a Collaborative Robotic System for the Shoe-Polishing Process

Demand for automated processes in the manufacturing industry is now shifting toward flexible, human-centered systems that combine productivity and high product quality, thus combining the advantages of automated and robotic systems with the high-value-added skills of operators and craftsmen. This trend is even more crucial for small and medium-sized enterprises operating in the “Made in Italy” fashion industry. The paper presents the study, simulation, and preliminary testing of a collaborative robotic system for shoe polishing that can reduce manual labor by limiting it to the finishing stage of the process, where the aesthetic result is fully achieved, with a benefit also in terms of ergonomics for the operator. The influence of process parameters and design solutions are discussed by presenting preliminary test results and providing hints for future developments