1,720,959 research outputs found
Mitigating Compensatory Movements in Prosthesis Users via Adaptive Collaborative Robotics
No full textProsthesis users can regain partial limb functionality, however, full natural limb mobility is rarely restored, often resulting in compensatory movements that lead to discomfort, inefficiency, and long-term physical strain. To address this issue, we propose a novel human-robot collaboration framework to mitigate compensatory mechanisms in prosthesis users by exploiting their residual motion capabilities while respecting task requirements. Our approach introduces a personalised mobility model that quantifies joint-specific functional limitations and the cost of compensatory movements. This model is integrated into a constrained optimisation framework that computes optimal user postures for task performance, balancing functionality and comfort. The solution guides a collaborative robot to reconfigure the task environment, promoting effective interaction. We validated the framework using a new bodypowered prosthetic device for single-finger amputation, which enhances grasping capabilities through synergistic closure with the hand but imposes wrist constraints. Initial experiments with healthy subjects wearing the prosthesis as a supernumerary finger demonstrated that a robotic assistant embedding the user-specific mobility model outperformed human partners in handover tasks, improving both the efficiency of the prosthesis user's grasp and reducing compensatory movements in functioning joints. These results highlight the potential of collaborative robots as effective workplace and caregiving assistants, promoting inclusion and better integration of prosthetic devices into daily tasks
Electrically Conductive and Recyclable Biocomposite Coatings for Robotic Grippers and Touch Sensors
No full textAs automation expands across industries, robotics is becoming increasingly essential. However, the sector's growth raises concerns about sustainability, making crucial the integration of sustainable materials into robots. Many robotic systems rely on moving components, such as arms, touch sensors, and grippers, that frequently interact with humans or objects, making them highly susceptible to wear and tear. A promising strategy to address this challenge is designing easily replaceable parts made from green, recyclable materials using low-energy fabrication methods. This approach not only reduces waste generation but also enhances the functionality and durability of these critical components. In this work, electrically conductive biocomposite coatings that functionalize a commercial foam are presented, enabling its use as a robotic gripper or as a touch sensor based on piezoresistive or piezocapacitive feedback mechanism, respectively. The conductive coatings are composed of polybutylene adipate terephthalate biodegradable polymer binder and carbon fillers, achieving sheet resistance in the order of kΩ sq−1, and are chemically recyclable. The coated foams have stable performance, exhibiting low hysteresis piezoresistive and piezocapacitive responses over 100 deformation cycles, making them a viable solution as robotic grippers and touch sensors. Using sustainable and recyclable materials, the approach supports environmentally friendly practices in robotics and sensing applications
Assisting Gait Stability in Walking Aid Users Exploiting Biomechanical Variables Correlation
Get PDFWalking aids for individuals with musculoskeletal frailty or motor disabilities must ensure adequate physical support and assistance to their users. To this end, sensor-enabled human state monitoring and estimation are crucial. This letter proposes an innovative approach to assessing users' stability while walking with WANDER, a novel gait assistive device, by exploiting the correlation between the eXtrapolated Center of Mass (XCoM) and the Base of Support (BoS) edges. First, the soundness of this metric in monitoring gait stability is proven. Experiments on 25 healthy individuals show that the median value of Pearson's correlation coefficient (p-value < 0.05) remained high during the forward walk for all subjects. Next, a correlation-based variable admittance (CVA) controller is implemented, whose parameters are tuned to physically support users when a gait perturbation is detected (i.e. low values of Pearson's correlation coefficient). To validate this approach, 13 healthy subjects were asked to compare our controller with a force threshold-based (FVA) one. The CVA controller's performance in discriminating stable and perturbed gait conditions showed a high sensitivity value, comparable to FVA, and improved performance in terms of specificity. The number of false and missed detections of gait perturbation was considerably reduced, independently of walking speed, exhibiting a higher level of safety and smoothness compared to the FVA controller. Overall, the outcome of this study gives promising evidence of the proposed metric capability in identifying user stability and triggering WANDER's assistance
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A mini-robot using self-learning for navigation
Get PDFThe robot described in this thesis is aimed at being used for research on machine learning. The idea was to provide an interface to the physical world to a neural network running on a host computer. This thesis describes the background literature, designed robot, as well as a charging station which enabled the robot to recharge itself. The main focus of this work was to build a robot as small as possible, without designing custom actuators or batteries. The final size of the robot is of 2.7 cm3, which is much smaller than the smallest robot designed so far with significant sensing capabilities(TinyTERP with extension board, 7.65 cm3), to the best of my knowledge
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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