1,721,068 research outputs found
Impact force identification in cobots: A preliminary work
No full textNowadays, cobots have become common in manufacturing industry collaborating with human agents and are predicted to be increasingly part of our lives. Whether it is industrial or service robots, the recent trend is to focus on what has been called human-robot collaboration (HRC). This poses a critical issue regarding the safety of human agents interacting with robot agents. Detecting a collision and executing an appropriate control strategy to reduce impact damages has been proven to be as an effective way to ensure a safe environment for human agents. This paper evaluates an approach for the complete identification of impact action in terms of point of application, intensity, and direction under some illustrative assumptions on robot geometry and system dynamics using only the sensors already present in the robot control system. Simulations have been carried out and their results suggest that the presented approach might be viable for collision detection, isolation, and identification
The robot selection problem for mini-parallel kinematic machines: A task-driven approach to the selection attributes identification
No full textIn the last decades, the Robot Selection Problem (RSP) has been widely investigated, and the importance of properly structuring the decision problem has been stated. Crucial aspect in this process is the correct identification of the robot attributes, which should be limited in number as much as possible, but should be also able to detect at best the peculiar requirements of specific applications. Literature describes several attributes examples, but mainly dedicated to traditional industrial tasks, and applied to the selection of conventional industrial robots. After a synthetic review of the robot attributes depicted in the RSP literature, presented with a custom taxonomy, this paper proposes a set of possible requirements for the selection problem of small scale parallel kinematic machines (PKMs). The RSP is based on a task-driven approach: two mini-manipulators are compared as equivalent linear actuators to be integrated within a more complex system, for the application in both an industrial and a biomedical environment. The set of identified criteria for the two environments is proposed in the results and investigated with respect to working conditions and context in the discussion, emphasizing limits and strength points of this approach; finally, the conclusions synthesizes the main results
Robotic System for Hand Rehabilitation Based on Mirror Therapy
No full textThe paper presents the study of a system composed by a sensorized glove that could interface with GLOREHA Lite hand exoskeleton. The movement of each GLOREHA’s motor acts on the flexion or extension of the corresponding finger through a cable transmission, allowing the user to carry out robot-assisted rehabilitation therapy for the hand. The combined use of GLOREHA and of the sensing glove allows performing a bimanual therapy using the Mirror Therapy technique, with the effect of increasing the effectiveness of the treatment. A test bench was used for the characterization of the bending sensors inserted into the sensing glove to detect flexion and extension of the fingers. Two sensor gloves were developed; one made of tissue, where the sensors are inserted into appropriate seams, and one made of Silicon, where the sensors were incorporated between two layers of material. Both solutions proved to be adequate. The characterised sensors have shown performances suitable for this type of application, while the tests on the responsiveness of GLOREHA to the command signal are good for both serial and Bluetooth communication. The presented system favors the achievement of the objectives of pillar three of the sustainable development goals (SDG): good health and well-being. An effective rehabilitation activity at home can allow a greater number of people, compared to the current one, to more quickly recover the motor functions of the hand
Soft Gloves: A Review on Recent Developments in Actuation, Sensing, Control and Applications
Full text linkInterest in soft gloves, both robotic and haptic, has enormously grown over the past decade, due to their inherent compliance, which makes them particularly suitable for direct interaction with the human hand. Robotic soft gloves have been developed for hand rehabilitation, for ADLs assistance, or sometimes for both. Haptic soft gloves may be applied in virtual reality (VR) applications or to give sensory feedback in combination with prostheses or to control robots. This paper presents an updated review of the state of the art of soft gloves, with a particular focus on actuation, sensing, and control, combined with a detailed analysis of the devices according to their application field. The review is organized on two levels: a prospective review allows the highlighting of the main trends in soft gloves development and applications, and an analytical review performs an in-depth analysis of the technical solutions developed and implemented in the revised scientific research. Additional minor evaluations integrate the analysis, such as a synthetic investigation of the main results in the clinical studies and trials referred in literature which involve soft gloves
Suppression of virus replication by prostaglandin A is associated with heat shock protein synthesis
No full textThe antiviral action of cyclopentenone prostaglandins (PGs) is generally associated with alterations in the synthesis and/or maturation of specific virus proteins. In particular, inhibition of Sendai virus (SV) replication in African green monkey kidney cells by PGA1 has been shown to be a cell-mediated event, due to alterations in SV protein glycosylation and accompanied by the induction of a cellular polypeptide of M(r) 74K. In this report we identify this protein as a heat shock protein (HSP) related to the major 70K HSP group (HSP70). Induction of HSP70 synthesis by PGA1 was found to be dose-dependent, and an accumulation of HSP70 comparable to that occurring after heat shock could be obtained at concentrations of PGA1 that did not inhibit macromolecular synthesis in uninfected cells, but caused a dramatic block of virus replication in SV-infected cells. Induction of HSP70 by PGA1 occurred at the transcriptional level and was not affected by SV infection. HSP70 synthesis was evident between 2 and 3 h after PGA1 treatment, maximal at 12 h and went back to control levels by 26 h after the addition of PGA1, thus preceding virus protein synthesis. Finally, of several PGs tested, only those which possess antiviral activity induced the synthesis of HSP70. These results, together with the observation that suppression of HSP70 synthesis by actinomycin D also abolishes the PGA1-induced alteration of SV glycoproteins, suggest that HSP70 could play a role in the block of virus replication by cyclopentenone PGs
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
An Innovative Shape Memory Actuator
No full textThe work describes a NiTi linear actuator. This material is able to realize a contraction with heating produced through Joule effect. Then a cooling of the active device is realized with forced air. Finally the lengthening is realized with another active element. The particular structure of the geometry allows for an increment of reliability, because the electrical connections are mechanically stabilized and the active elements are compelled to avoid undesired electrical contacts through an insulated cylindrical core
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