1,721,077 research outputs found
Robotic Non-Destructive Testing
Full text linkNon-destructive testing (NDT) and evaluation (NDE) are commonly referred to as the vast group of analysis techniques used in civil, medical, and industrial sectors to evaluate the properties of materials, tissues, components, or structures without causing any damage [...]
Adding Autonomy to Robotic Enabled Sensing
No full textThe capabilities of most non-destructive testing methods have been combined with some degree of automation in recent years, to enhance data acquisition speed, part coverage and inspection reliability. A plethora of automated or semi-automated inspection systems have been engineered to enable the robotic manipulation of specific types of sensors. Robotic inspection systems are usually operated through off-line programmed tool-paths. This approach works well when an accurate model of the part is available and the robotic inspection takes place in a well-structured environment, where the part position is precisely registered with respect to the robot reference system. However, it makes the inspection setup for each new part very time-consuming and dependent on the skills and experience of the robot programmer. Moreover, the real geometry of a part may significantly deviate from its digital counterpart, resulting in inaccurate tool paths. This work introduces a new approach capable of conferring full autonomy to robotic sensing applications, providing a breakthrough in the stateof-the-art. As a result of this work, fully autonomous single-pass geometric and volumetric inspection of complex parts, using one single robotized sensor, becomes possible. This concept can find wide applicability to the open problems of structural health monitoring of the modern age
Surface waves on cylindrical solids: Numerical and experimental study
No full textThe use of Rayleigh waves enables the solution of several important inspection problems. Propagation of
surface waves along straight boundaries has been properly studied but investigations about their propagation on cylindrical surfaces are not sufficient, despite they can be still of interest for NDE applications.
It has been proved experimentally that a surface wave pulse suffers a phase shift during its propagation
along a cylindrical surface. A numerical approach has been developed to efficiently study these effects for
different materials, curvatures and frequencies. This study can help the scientific community to better
understand the phenomenon, quite complex and not yet fully explored
Numerical study for a new methodology of flaws detection in train axles
No full textTrain loads and travel speeds have increased over time, requiring more efficient non-destructive inspection methods. Railway axles are critical elements; despite being designed to last more than 20 years several cases of premature failure have been recorded. Train axles are inspected regularly, but the limits associated to the traditional inspection technologies create a growing interest towards new solutions. Here a novel non-destructive inspection method of in-service axles based on non-contact data collection is presented. The propagation of surface waves, generated by a thermo-elastic laser source, is investigated using a finite element method based on dynamic explicit integration. Coupled thermo-mechanical simulations allow visualization of the ultrasonic field guiding the definition of the optimal NDT setup. The geometry of the axle and of the elements mounted on it is accurately reproduced; moreover the press fit effect caused by the wheel and the bearing rings is implemented. The current NDT techniques for railway axles require removing wheels and other components from the axle. The presented scheme uses non-contact ultrasonic generation and detection allowing non-contact in-service inspection of railway axles at trackside station. The numerical results are promising and encourage us to test the new approach experimentally
Mimicking human autonomy in industrial robotic enabled sensing
No full textHumans have an immediate perception of shapes and surroundings through their senses and their cognitive capabilities. This innate ability enables the manual inspection of components in manufacturing environments. Trained inspectors combine their senses and handling skills with bespoke non-destructive testing instrumentation. However, manual inspections can be slow for large and/or complex geometries and prone to human factors. Automated non-destructive testing systems have emerged in recent years, to increase data acquisition speed, part coverage and inspection reliability. These tools work well when the robotic inspection takes place in a well-structured environment and an accurate part model is available. However, precisely registering the position of a part in the robot reference system makes the inspection setup very time-consuming. Furthermore, the geometry of a part may differ from its digital model, spoiling the inspection accuracy. This work introduces a new approach that mimics the human perception capability and gives full manipulation autonomy to robotic sensing applications. We use a single robotized sensor to introduce a fully autonomous single-pass geometric and volumetric inspection of complex parts. Our approach can be used to solve some key challenges in quality assurance for Industry 4.0 and can find applicability beyond robotic non-destructive testing
GRUPPI, GIOVANI ADULTI E DISIDENTITÀ
No full textIntroduzione
In connessione con i cambiamenti socio-antropologici che caratterizzano la nostra epoca post-moderna, si è proposto il concetto di disidentità (Ferraro, Lo Verso, 2007, 2008; Ferraro, 2011; Ferraro, Giannone, Lo Verso, 2012) come chiave di lettura della condizione esistenziale espressa oggi da molti giovani-adulti e come cartina di tornasole rispetto all’affermarsi di nuovi quadri psicopatologici.
Lo studio analizza i vissuti legati al tema della disidentità, per individuarne le forme d’espressione e valutare le capacità del gruppo d’intervenire su di essi.
Metodo
In 3 focus group (21 giovani adulti) a conduzione psicodinamica, sono stati somministrati prima e dopo l’esperienza di gruppo, test che esplorano alcuni livelli di organizzazione dell’identità: differenziazione del sé (DSI-R, Skowron, Fiedlander, 1998; Skowron, Schmitt, 2003), modalità relazionali (IIP, Horowitz et al., 1988), autostima (R-SES (Rosenberg, 1965; Prezza, Trombaccia, 1997), eventuali sofferenze psichiche, con particolare riguardo agli ambiti relazionali e lavorativi (OQ-45, Lambert et al., 1996; Lo Coco et al., 2006).
Per i processi di gruppo (pre-post), sono stati utilizzati: GQ (Bormann, et al., 2011 ), CALPAS-group (Gaston, Marmar, 1993), GMLCS (Piper et al., 1983). Sono state condotte analisi descrittive e di associazione.
Risultati
Cambiamenti positivi significativi emergono in diversi aspetti indagati. Molti sono significativamente associati tra loro. Il processo dei gruppi rivela un crescendo di coesione e alleanza. Meno numerose ma interessanti sono le associazioni tra gli indici di processo e quelli di esito.
Conclusioni
Lo studio ha consentito d’individuare componenti empiriche utili alla prosecuzione della riflessione clinica sulla disidentità. I risultati consentono anche approfondimenti sul set(ting) gruppale, come esperienza sociale favorevolmente associata al miglioramento delle condizioni indagate
Autonomous Robotic Sensing for Simultaneous Geometric and Volumetric Inspection of Free-Form Parts
Full text linkRobotic sensing is used in many sectors to improve the inspection of large and/or complex parts, enhancing data acquisition speed, part coverage and inspection reliability. Several automated or semi-automated solutions have been proposed to enable the automated deployment of specific types of sensors. The trajectory to be followed by a robotic manipulator is typically obtained through the offline programmed tool paths for the inspection of a part. This method is acceptable for a part with known geometry in a well-structured and controlled environment. The part undergoing assessment needs to be precisely registered with respect to the robot reference system. It implies the need for a setup preparation phase for each new part, which can be very laborious and reliant on the human experience. This work combines real-time robot control and live sensor data to confer full autonomy to robotic sensing applications. It presents a novel framework that enables fully autonomous single-pass geometric and volumetric inspection of complex parts using one single robotised sensor. A practical and robust robot control sequence allows the autonomous correction of the sensor orientation and position to maximise the sensor signal amplitude. It is accompanied by an autonomous in-process path planning method, capable of keeping the inspection resolution uniform throughout the full extension of the free-form parts. Last but not least, a by-product of the framework is the progressive construction of the digital model of the part surface throughout the inspection process. The introduced framework is scalable and applicable to widely different fields
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