785 research outputs found

    Automatic Fracture Characterization Using Tactile and Proximity Optical Sensing

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    This paper demonstrates how tactile and proximity sensing can be used to perform automatic mechanical fractures detection (surface cracks). For this purpose, a custom-designed integrated tactile and proximity sensor has been implemented. With the help of fiber optics, the sensor measures the deformation of its body, when interacting with the physical environment, and the distance to the environment's objects. This sensor slides across different surfaces and records data which are then analyzed to detect and classify fractures and other mechanical features. The proposed method implements machine learning techniques (handcrafted features, and state of the art classification algorithms). An average crack detection accuracy of ~94% and width classification accuracy of ~80% is achieved. Kruskal-Wallis results (p < 0.001) indicate statistically significant differences among results obtained when analysing only integrated deformation measurements, only proximity measurements and both deformation and proximity data. A real-time classification method has been implemented for online classification of explored surfaces. In contrast to previous techniques, which mainly rely on visual modality, the proposed approach based on optical fibers might be more suitable for operation in extreme environments (such as nuclear facilities) where radiation may damage electronic components of commonly employed sensing devices, such as standard force sensors based on strain gauges and video cameras

    Flight Avionics Hardware Roadmap

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    As part of NASA's Avionics Steering Committee's stated goal to advance the avionics discipline ahead of program and project needs, the committee initiated a multi-Center technology roadmapping activity to create a comprehensive avionics roadmap. The roadmap is intended to strategically guide avionics technology development to effectively meet future NASA missions needs. The scope of the roadmap aligns with the twelve avionics elements defined in the ASC charter, but is subdivided into the following five areas: Foundational Technology (including devices and components), Command and Data Handling, Spaceflight Instrumentation, Communication and Tracking, and Human Interfaces

    The Use of Tactile Sensors in Oral and Maxillofacial Surgery: An Overview

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    Background: This overview aimed to characterize the type, development, and use of haptic technologies for maxillofacial surgical purposes. The work aim is to summarize and evaluate current advantages, drawbacks, and design choices of presented technologies for each field of application in order to address and promote future research as well as to provide a global view of the issue. Methods: Relevant manuscripts were searched electronically through Scopus, MEDLINE/PubMed, and Cochrane Library databases until 1 November 2022. Results: After analyzing the available literature, 31 articles regarding tactile sensors and interfaces, sensorized tools, haptic technologies, and integrated platforms in oral and maxillofacial surgery have been included. Moreover, a quality rating is provided for each article following appropriate evaluation metrics. Discussion: Many efforts have been made to overcome the technological limits of computed assistant diagnosis, surgery, and teaching. Nonetheless, a research gap is evident between dental/maxillofacial surgery and other specialties such as endovascular, laparoscopic, and microsurgery; especially for what concerns electrical and optical-based sensors for instrumented tools and sensorized tools for contact forces detection. The application of existing technologies is mainly focused on digital simulation purposes, and the integration into Computer Assisted Surgery (CAS) is far from being widely actuated. Virtual reality, increasingly adopted in various fields of surgery (e.g., sino-nasal, traumatology, implantology) showed interesting results and has the potential to revolutionize teaching and learning. A major concern regarding the actual state of the art is the absence of randomized control trials and the prevalence of case reports, retrospective cohorts, and experimental studies. Nonetheless, as the research is fast growing, we can expect to see many developments be incorporated into maxillofacial surgery practice, after adequate evaluation by the scientific community

    Machine Systems for Exploration and Manipulation: A Conceptual Framework and Method of Evaluation

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    A conceptual approach to describing and evaluating problem-solving by robotic systems is offered. One particular problem of importance to the field of robotics, disassembly, is considered. A general description is provided of an effector system equipped with sensors that interacts with objects for purposes of disassembly and that learns as a result. The system\u27s approach is bottom up, in that it has no a priori knowledge about object categories. It does, however, have pre-existing methods and strategies for exploration and manipulation. The sensors assumed to be present are vision, proximity, tactile, position, force, and thermal. The system\u27s capabilities are described with respect to two phases: object exploration and manipulation. Exploration takes the form of executing exploratory procedures, algorithms for determining the substance, structure, and mechanical properties of objects. Manipulation involves manipulatory operators, defined by the type of motion, nature of the end-effector configuration, and precise parameterization. The relation of the hypothesized system to existing implementations is described, and a means of evaluating it is also proposed

    Flexible Micro-Nano Fiber Sensors for Tactile Sensing

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    Flexible tactile sensors play an important role in wearable devices, human–computer interaction devices, and advanced robotics. We propose a novel structure of bionic flexible tactile sensor. The micro-nano fibers (MNFs) are packed in a 10-μm film on a polydimethylsiloxane (PDMS) base, forming a thin film-MNF-PDMS structure. A ridge-shaped sensing region is formed on the surface of the PDMS substrate. The MNF is so close to the sensor surface that vibration and pressure signals can act directly on the MNF. Compared to existing MNF flexible sensors, this sensor has higher sensitivity and faster response time. We tested the response of the flexible sensor to vibration and temperature. This sensor can measure vibration signals from 0.1 Hz to2 kHz. The sensitivity of this sensor to temperature can reach 1.43 nm/◦C. Surfaces with different roughness or texture can be distinguished by sliding on the sensor surface. The structural and functional characteristics of this sensor are desirable in flexible bionic devices and advanced robots

    Sensors for Robotic Hands: A Survey of State of the Art

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    Recent decades have seen significant progress in the field of artificial hands. Most of the surveys, which try to capture the latest developments in this field, focused on actuation and control systems of these devices. In this paper, our goal is to provide a comprehensive survey of the sensors for artificial hands. In order to present the evolution of the field, we cover five year periods starting at the turn of the millennium. At each period, we present the robot hands with a focus on their sensor systems dividing them into categories, such as prosthetics, research devices, and industrial end-effectors.We also cover the sensors developed for robot hand usage in each era. Finally, the period between 2010 and 2015 introduces the reader to the state of the art and also hints to the future directions in the sensor development for artificial hands
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