1,720,986 research outputs found
Hybrid Rigid–Soft Industrial Gripper: Actuation, Design Enhancement, Multi-Modal Sensorization, and Real-Time Coordinated Control for Automotive Assembly
No full textThe growing complexity of industrial automation and the shift toward human–robot collaborative manufacturing demand robotic grippers that combine mechanical precision, adaptive compliance, and intelligent sensing. This doctoral thesis addresses these needs through comprehensive research on actuation mechanisms, kinematic analysis, design enhancement, advanced sensorization, and industrial implementation of a versatile universal gripper system capable of handling components from delicate items to complex rigid parts. In parallel, it contributes to industrial robot control within the EU Horizon SESTOSENSO project.
The work begins with a detailed kinematic analysis of a novel three-finger gripper architecture. Each rigid mechanical finger integrates a Chebyshev–parallelogram linkage mechanism with a thermoplastic polyurethane (TPU) contact interface. The mechanism produces near-linear trajectories with a deviation of ±0.033 mm and a mechanical advantage of 6.06:1. Independent actuation is achieved using JVL stepper motors with embedded programmable logic controllers (PLCs), communicating via Modbus remote terminal unit (RTU). The control architecture supports torque-based and velocity-based stall detection, both operating in real time with configurable thresholds. These strategies enable reliable grasping without dedicated force sensors by leveraging internal motor feedback parameters.
Gripper enhancement is guided by a quantitative deflection coefficient to assess finger wrapping and by quasi-static force–displacement testing. The original four-bar parallelogram was redesigned into a six-bar linkage with compliant pads. This eliminates link interference limitations while preserving the essential kinematics, resulting in adaptive grasping capability. Pull-out tests demonstrated improved force profiles for complex automotive parts and reliable manipulation of objects from 100 g to 7.5 kg.
Vision-based sensorization was achieved through an embedded Raspberry Pi Camera V3.
The integration of vision-based sensing within the additively manufactured soft finger structure establishes the feasibility of achieving multiple sensing modalities with a single compact embedded system while retaining the characteristic properties of the fingers. The proposed system successfully estimates normal interaction forces, measures internal deformation (Z-displacement), classifies the position of the applied force, and detects slip events with the complete sensing pipeline processed on an embedded platform while avoiding complex signal disambiguation challenges and occlusion issues. Complementing this, a fully flexible resistive sensor was fabricated via fused deposition modeling (FDM) printing and embedded in the finger for contact and bending detection. A novel light-angle sensor array was also developed using a custom four-layer rigid-flex printed circuit board (PCB), where prototype sensors successfully demonstrate distributed tactile sensing capabilities.
The universal gripper and sensing systems were validated on a COMAU six-degrees-of-freedom (6-DOF) industrial robot in diverse grasping trials, confirming adaptability, robustness, and sensing reliability. Separately, within the SESTOSENSO project, real-time control strategies were developed for coordinating a KUKA KR150 robot with a UR10 cobot via robot sensor interface (RSI) and robot operating system (ROS) in an automotive roof assembly task. This work addressed control architecture, real-time trajectory correction, and safe human–robot collaboration in confined, visually occluded environments.
This thesis advances the state of the art in hybrid gripper systems by integrating rigid precision, soft adaptability, and intelligent sensing with industrially validated control strategies. The outcomes directly support Industry 4.0/5.0 objectives, enabling flexible, high-performance automation adaptable to diverse manufacturing requirements
Design and fabrication of resistive sensor using additive manufacturing techniques for robotic application
No full textSalvia coccinea and Apigenin: A Natural Treasure of Lamiaceae in Pharmacological Innovation
No full textElectrochemical performance enhancement of MnO2 nanowires through silver incorporation for next-generation supercapacitors
Full text linkIncreased demand for effective energy storage systems emphasizes the urgency to overcome the bottlenecks of existing technology. Supercapacitors (SCs), owing to their high specific power and fast charging/discharging capabilities, are perfect candidates for future energy applications but their low energy density makes them impractical for commercial applications. Because of their high energy density and variable oxidation states, transition metal oxides (TMOs) have great potential as supercapacitor electrode materials. But for practical applications, their poor intrinsic conductivity needs to be improved. Noble metal doping offers a compelling method to raise the conductivity and structural stability of TMOs. Herein, we have prepared AgxMnO2 (x = 0.05, 0.10, and 0.15) to improve the conductivity and structural stability of the electro-active material. FESEM micrographs exhibit cracks on the nanowire (NW) surface by Ag doping, proposing less dead volume. Ag doping also fortified electrode pulverization during charging/discharging cycles by imparting structural stability. These properties enabled Ag0.05MnO2 NWs to demonstrate a specific capacitance of 1027 F g−1 at a current density of 1 A g−1. The electrode also retained a capacitance of 93.16% after 10[thin space (1/6-em)]000 GCD cycles@12 A g−1 along with 86% rate capability at 9 A g−1. By tackling critical difficulties such as poor conductivity and structural stability, this study advances energy storage technologies and lays the groundwork for the creation of high-performance supercapacitors for future energy applications.This article is published as Khalid, Muhammad Usman, Sonia Zulfiqar, M. Naziruddin Khan, Imran Shakir, Muhammad Farooq Warsi, and Eric W. Cochran. "Electrochemical performance enhancement of MnO 2 nanowires through silver incorporation for next-generation supercapacitors." Materials Advances (2024). doi: https://doi.org/10.1039/D4MA00118D. This Open Access Article is licensed under (http://creativecommons.org/licenses/by-nc/3.0/)
Investigating the Influence of Sodium Preintercalation on the Electrochemical Behavior of Ultrathin MnO2 Nanowires for Enhanced Supercapacitor Performance
Full text linkWe have successfully synthesized bare and Na+ preintercalated MnO2 nanowires (NWs) (NaxMnO2, x = 0.05, 0.1, and 0.15) using a facile hydrothermal method. Supercapacitors are the state-of-the-art technology to overcome the global energy crisis, owing to their fast charging/discharging rates and higher power density. One-dimensional morphology (nanorods, nanowires, etc.) boosts the inherent low conductivity of transition metal oxides including MnO2 by confining charge transport only in one direction. Here, we have preintercalated Na+ ions into MnO2 nanowires (NWs) as a conductivity booster as well as a tunnel-stabilizing agent for α-MnO2. Morphological analysis reveals that nanowires have <50 nm diameter and their surface gets cracked with Na+ preintercalation, offering a less dead area. Linear sweep voltammetry (LSV) results revealed an increase in oxygen evolution overpotential by Na+ preintercalation, which can enable the supercapacitor to operate at an extended potential window. Na+ preintercalation and control on morphology not only increased the conductivity but also shielded the electrode pulverization against tedious charging/discharging cycles and reduced the electrolyte diffusion pathway. These features enabled Na0.10MnO2 NWs to exhibit a specific capacitance of 1061 F g–1@1 A g–1 and an excellent rate capability of 85.6% at 9 A g–1 along with 95.9% capacitance retention after 6000 charging–discharging cycles at 12 A g–1 current density. This study showed that Na+ preintercalation in MnO2 could improve the electrochemical performance and open up new horizons to manufacture high-performance next-generation supercapacitors.This is a manuscript of the article Published as Khalid, Muhammad Usman, Sonia Zulfiqar, Muhammad Farooq Warsi, Imran Shakir, M. S. Al-Buriahi, and Eric W. Cochran. "Investigating the Influence of Sodium Preintercalation on the Electrochemical Behavior of Ultrathin MnO2 Nanowires for Enhanced Supercapacitor Performance." Energy & Fuels (2024).
doi: https://doi.org/10.1021/acs.energyfuels.3c04027. Copyright © 2024 American Chemical Society. Posted with Permission
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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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