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e-Journal of Nondestructive Testing 2023年第1期28卷

作者： Klimek, Zbigniew Paćko, Pawel Cracow branch Warsaw Poland AGH University of Science and Technology Faculty of Mechanical Engineering and Robotics Department of Robotics and Mechatronics Krakow Poland

This paper discusses challenges, limitations and problems arising in currently employed acoustic emission testing systems, sensors and signal processing algorithms. Main factors influencing and compromising accuracy and reliability of the classically used methods are briefly analyzed. Next, metamaterials and their dynamic properties are outlined with the aim and focus on their potential in manipulating energy flow. Several applications of metamaterials in acoustic emission are presented that indicate their potential in acoustic emission. Finally, possibilities of designing a new type of sensor for acoustic emission using metamaterials is discussed. As a consequence, it is expected to increase sensitivity and accuracy of source localization with smaller number of sensors used during measurements. © 2023 The Authors.

关键词： Metamaterials

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PEMF Device with Bipolar Pulse Waves Based on Single Chip Computer 8

PEMF Device with Bipolar Pulse Waves Based on Single Chip Co...

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2022 8th International Conference on mechanical engineering, Materials and Automation Technology, MMEAT 2022

作者： Tai, Au-Zou Fang, Jiunn Ph.D. Program of Mechanical and Aeronautical Engineering Feng Chia University Taichung40724 Taiwan Department of Aerospace and Engineering Feng Chia University Taichung City Taiwan

PEMF therapy, a non-invasive technology, is frequently reported in medical journals. It can send electric and magnetic fields to the body through induction coils [1,2], so as to provoke cells to stimulate nerves and muscles. Based on performances of large PEMF equipment on the market, on average, the low frequency emitted by most PEMF equipment is 0-300HZ An appropriate single chip is selected to make an extremely low frequency 0-30HZ that can be easily developed and easily changed. And has bipolar pulse wave so that simple equipment can also get enough effect. © Published under licence by IOP Publishing Ltd.

关键词： Condensed matter physics

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Understanding Acoustic Phenomena in Stenosed Coronary Arteries through Bond Graph Modeling of Sound Generation

Understanding Acoustic Phenomena in Stenosed Coronary Arteri...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Loreto Rojas Sandoval René Araya Ulloa Ana Karoline Almeida Da Silva Gustavo Adolfo Marcelino de Almeida Nunes Rafael Mendes Faria José Parra Sepúlveda Lindemberg Barreto Mota Da Costa Luca Rubilar Acevedo Mário Fabrício Fleury Rosa Esteban J. Pino Suélia de Siqueira Rodrigues Fleury Rosa Electrical Engineering Department Universidad de Concepción Chile Mechanical Engineering Department University of Brasilia Brasilia Brazil Postgraduate Program in Biomedical Engineering University of Brasilia Brasilia Brazil

ISBN: (数字)9798350371499

ISBN: (纸本)9798350371505

Coronary artery stenosis is characterized by the obstruction or narrowing of coronary arteries, impairing blood flow to the cardiac muscle. Cardiovascular diseases rank among the leading global causes of death. Understanding the mechanisms, risk factors, and impacts of coronary artery stenosis (CAD) is essential for developing effective strategies for prevention, early diagnosis, and treatment, aiming to enhance cardiovascular health and reduce adverse consequences associated with this condition. Previous studies explore the potential of acoustic devices in non-invasive CAD detection through the analysis of cardiac sounds. A theoretical model utilized a cardiac microphone and signal processing to generate sounds in partially obstructed coronary arteries. Emphasizing the model’s sensitivity to geometric and dynamic parameters, this article integrates Bond Graph (BG) models into the analog sound circuit, aiming to develop a dynamic representation of biological processes in complex systems like coronary arteries. This research seeks to construct a comprehensive mathematical model using a state-space approach to enhance understanding, diagnostics, and interventions in cardiovascular conditions. The utilization of BG demonstrated notable similarity to the pathology of the disease, providing an accurate representation of its effects. The model’s sensitivity to geometric and dynamic parameters allowed an in-depth understanding of the specific physiological characteristics of the disease, highlighting its ability to reproduce patterns observed in patients with CAD.

关键词： Solid modeling Analytical models Pathology Sensitivity Biological system modeling Prevention and mitigation Signal processing Predictive models Mathematical models Arteries

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Examining the Usability and Security Features of Smart Farm IoT Systems

Examining the Usability and Security Features of Smart Farm ...

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2023 International Conference on Power Energy, Environment and Intelligent Control, PEEIC 2023

作者： Khawale, Vijay R. Fidvi, Huzaifa A. Shamout, Mohamed Dawood Nama, Gigih Forda Anute, Nilesh Limbore, Nilesh Yeshwantrao Chavan College of Engineering Mechanical Department Nagpur India Anjuman College of Engineering and Technology Mechanical Engineering Sadar Maharashtra Nagpur India College of Business Administration University of Sharjah Department of Management Sharjah United Arab Emirates University of Lampung Department of Informatics Doctoral Program of Environtmental Science Bandar Lampung Indonesia ASM's Institute of Business Management and Research Pune India Sharadchandra Pawar Institute of Management and Research Pune India

ISBN: (纸本)9798350357769

Using the net of factors (IoT) technology has led to a resurgence in improving intelligent farms. The capacity to music and reveal crops, animals, and different farm activities has advanced the performance of farming operations. Clever farms enjoy the blessings of connectivity, allowing farmers to be more informed and higher prepared for any ability issues. This increased connectivity has also opened the door for new security problems. This paper looks at intelligent farm IoT structures' usability and safety features. The paper investigates the overall protection levels of the systems and the various security measures that may be implemented as an excellent way to discover and guard in opposition to ability threats. It also evaluates the usability of the structures and assesses the extent of convenience it offers for agriculture employees. The paper also evaluates the present-day enterprise tendencies in IoT protection, value, and potential future trends. Ultimately, the paper gives insights into modern and future security and usability measures that may be taken to ensure the protection and effectiveness of clever farm IoT systems. The paper examines the usability and protection capabilities of innovative Farm Internet of Things (IoT) structures, which provide farmers with the potential to monitor, manipulate, and control various farm elements remotely. Usability functions consisting of user interfaces, device connectivity, and communication protocols are analyzed to evaluate how user-friendly the device is. Additionally, safety functions consisting of authentication, authorization, encryption, and getting entry to manage are tested to decide how the gadget can defend the statistics and assets of the farm. Moreover, this paper touches upon the contemporary and destiny-demanding situations related to those structures, including scalability, cost, and privacy. ultimately, the paper concludes with a comprehensive assessment of the usability and security functions and

关键词： ability implemented increased intelligent opposition

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A Brief Overview of Delamination Localization in Laminated Composites

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Multiscale Science and engineering 2022年第3期4卷 102-110页

作者： Khan, Asif Kim, Heung Soo Faculty of Mechanical Engineering Ghulam Ishaq Khan Institute of Engineering Sciences and Technology Topi Pakistan Department of Mechanical Robotics and Energy Engineering Dongguk University-Seoul Seoul Korea

Inter-ply separation or delamination is a commonly occurring phenomenon in laminated composites that results in substantial loss of structural stiffness and strength without noticeable effects on the surface of the material. This article reviewed different approaches of delamination detection and localization ranging from physical based methods to the recent artificial intelligence-based algorithms. The relative advantages and disadvantages of different approaches are discussed so the readers could decide the appropriate method for their problems of interest. The article also discussed the possible research gaps to be bridged with new research efforts such as synthetic data augmentation, transfer learning, data imbalance, and others. The article will serve as quick yet comprehensive review of different approaches for the detection and localization of delamination in laminated composites.

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无人飞行器在不确定扰动下的动态目标跟踪

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engineering 2024年第4期35卷 74-85页

作者： Yanjie Chen Yangning Wu Limin Lan Hang Zhong Zhiqiang Miao Hui Zhang Yaonan Wang School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350108China Department of Computer Science Aberystwyth UniversityAberystwyth SY233DBUK School of Robotics Hunan UniversityChangsha 410082China College of Electrical and Information Engineering Hunan UniversityChangsha 410082China National Engineering Research Center of Robot Visual Perception and Control Technology Hunan UniversityChangsha 410082China

This study proposes an image-based visual servoing(IBVS)method based on a velocity observer for an unmanned aerial vehicle(UAV)for tracking a dynamic target in Global Positioning System(GPS)-denied *** proposed method derives the simplified and decoupled image dynamics of underactuated UAVs using a constructed virtual camera and then considers the uncertainties caused by the unpredictable rotations and velocities of the dynamic target.A novel image depth model that extends the IBVS method to track a rotating target with arbitrary orientations is *** depth model ensures image feature accuracy and image trajectory smoothness in rotating target *** relative velocities of the UAV and the dynamic target are estimated using the proposed velocity *** to the velocity observer,translational velocity measurements are not required,and the control chatter caused by noise-containing measurements is *** integral-based filter is proposed to compensate for unpredictable environmental disturbances in order to improve the antidisturbance *** stability of the velocity observer and IBVS controller is analyzed using the Lyapunov *** simulations and multistage experiments are conducted to illustrate the tracking stability,anti-disturbance ability,and tracking robustness of the proposed method with a dynamic rotating target.

关键词： Unmanned aerial vehicle Visual servoing Velocity observer Target tracking

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Embracing Safe Contacts with Contact-aware Planning and Control

arXiv

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arXiv 2023年

作者： Li, Zhaoting Zamora, Miguel Zheng, Hehui Coros, Stelian Computational Robotics Lab Computer Science Department ETH Zurich Switzerland Soft Robotics Lab Department of Mechanical and Process Engineering ETH Zurich Switzerland

Unlike human beings that can employ the entire surface of their limbs as a means to establish contact with their environment, robots are typically programmed to interact with their environments via their end-effectors, in a collision-free fashion, to avoid damaging their environment. In a departure from such a traditional approach, this work presents a contact-aware controller for reference tracking that maintains interaction forces on the surface of the robot below a safety threshold in the presence of both rigid and soft contacts. Furthermore, we leveraged the proposed controller to extend the BiTRRT sample-based planning method to be contact-aware, using a simplified contact model. The effectiveness of our framework is demonstrated in hardware experiments using a Franka robot in a setup inspired by the Amazon stowing task. A demo video of our results can be seen here: https://***/2WeYytauhNg. © 2023, CC BY.

关键词： End effectors

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A Geometry-based Approach for Support-free Additive Manufacturing of Structures with Large Overhang Angles and Closed Features

A Geometry-based Approach for Support-free Additive Manufact...

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IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

作者： Jitian Liu Zachary Cohen Jin Seob Kim Mehran Armand Michael D. M. Kutzer Department of Mechanical Engineering Johns Hopkins University Baltimore Maryland USA Department of Weapons Robotics & Control Engineering United States Naval Academy Annapolis Maryland USA Departments of Orthopaedic Surgery Mechanical Engineering & Computer Science Johns Hopkins University Baltimore Maryland USA

ISBN: (数字)9798350377705

ISBN: (纸本)9798350377712

Architected materials derive performance characteristics from material properties and internal geometry. These materials are increasingly prevalent across a wide variety of domains. Many intricate feature geometries associated with architected materials can be explored using additive manufacturing (AM) processes. However, current AM methods generally cannot fabricate geometries with completely closed voids without introducing a support structure. This paper describes a new, support-free approach to AM capable of creating structures with closed voids. This work limits part geometry to three-dimensional (3D) geometries defined by a revolution about a single axis. This limitation enables planar analysis within a three-degree-of-freedom (3-DoF) task space. Part geometry in 3-DoF task space is constrained to a convex arch. Task space geometry is divided into an ordered set of sub-regions, considering feasible deposition orientations and collision constraints. The use of 3-DoF task space provides planar translation and rotation of the component during fabrication. The introduction of this rotational DoF addresses AM overhang constraints imposed by gravity. Methods for generating, ordering, and layering sub-regions suitable for printing a part with a closed hole are presented. Layers derived in the 3-DoF task space analysis are then extended to 3D deposition paths using the axis of revolution defined by the original part. The method of hole closure relies on the concept of a "keystone" which requires a 45° nozzle offset for collision-free deposition within keystone-adjacent sub-regions. The feasibility of deposition using a 45° nozzle offset is explored experimentally, and results demonstrate feasibility.

关键词： Geometry Fabrication Translation 3-DOF Three-dimensional printing Intelligent robots Material properties Gravity

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A Review on Application of Poly(3,4-ethylenedioxythiophene) (PEDOT) in Rechargeable Batteries

Organic Materials

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Organic Materials 2022年第4期4卷 292-300页

作者： Su, Laisuo Kumar, Shwetha Sunil Manthiram, Arumugam Reeja-Jayan, B. Materials Science and Engineering Program Texas Materials Institute The University of Texas at Austin Austin 78712 TX United States Department of Mechanical Engineering Carnegie Mellon University Pittsburgh 15213 PA United States

Since the very first patent on poly(3,4-ethylenedioxythiophene) (PEDOT) that was filed in 1988, this polymer has been widely utilized and has achieved great success owing to its high electrical conductivity and excellent stability. The application of the conducting polymer, PEDOT, in renewable energy devices, especially rechargeable batteries, is attracting increasing attention due to its potential to solve the energy and climate crisis. In this review, we summarize the research over the past few decades directed toward the application of PEDOT in rechargeable batteries aimed at improving their electrochemical performance. We focus on PEDOT synthesized via oxidative chemical vapor deposition (oCVD), a relatively new process known for its ability to grow conducting polymer thin films with uniform, pinhole-free properties, and controllable thickness and conformality. For a comparison purpose, PEDOT synthesized via solution-based methods is also briefly summarized. Finally, future research directions for applying oCVD PEDOT in rechargeable batteries are discussed. Introduction PEDOT Synthesis Methods Application of oCVD PEDOT in Rechargeable Batteries Applications of Solution-Based PEDOT in Rechargeable Batteries Conclusions and Outlook. © 2022. The Author(s).

关键词： batteries coating oxidative chemical vapor deposition (oCVD) polyethylene dioxythiophene (PEDOT)

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SIGMA: A Minimalistic 3D Hopping Robot with Parallel 3-RSR Mechanism for Safeguarding Humanitarian Demining

SIGMA: A Minimalistic 3D Hopping Robot with Parallel 3-RSR M...

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IEEE International Workshop on Safety, Security, and Rescue robotics (SSRR)

作者： C. Y. Ivan Fan Xiangyu Chu F. Y. Fiat Wong Fan Shi K. W. Samuel Au Department of Mechanical and Automation Engineering The Chinese University of Hong Kong Hong Kong SAR Department of Mechanical Engineering Johns Hopkins University USA Multiscale Medical Robotics Centre Hong Kong SAR National University of Singapore Singapore

ISBN: (数字)9798331510954

ISBN: (纸本)9798331510961

Humanitarian demining is a pressing task to safeguard the lives of civilians living near minefields and free up land occupied by landmines for development. Conventional demining robots, while capable of demining, have a high cost and can be damaged during demining. In this work, we propose SIGMA, a SIngle-leG Mine-clearing Assistant Robot, which is a lightweight and low-cost robotic tool that can complement conventional manual and robotic demining efforts. It is a hopping monopod robot based on a parallel spatial leg mechanism with the capability of omnidirectional movement and force. During the demining process, SIGMA can be deployed ahead of human or robotic deminers to trigger unstable mines and chart a safe path for traversing, reducing risks to deminers. A prototype of SIGMA is designed and built. Its capability to traverse and activate mines is also verified experimentally in simulated scenarios.

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