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A series elastic actuator design and control in a linkage based hand exoskeleton

ASME 2019 Dynamic Systems and Control Conference, DSCC 2019

作者： Chauhan, Raghuraj J. Ben-Tzvi, Pinhas Robotics and Mechatronics Lab Department of Mechanical Engineering Virginia Tech BlacksburgVA24060 United States

ISBN: (纸本)9780791859162

This paper presents the design of a series elastic actuator and a higher level controller for said actuator to assist the motion of a user's hand in a linkage based hand exoskeleton. While recent trends in the development of exoskeleton gloves has been to exploit the advantages of soft actuators, their size and power requirements limit their adoption. On the other hand, a series elastic actuator can provide compliant assistance to the wearer while remaining compact and lightweight. Furthermore, the linkage based mechanism integrated with the SEA offers repeatability and accuracy to the hand exoskeleton. By measuring the user's motion intention through compression of the elastic elements in the actuator, a virtual dynamic system can be utilized that assists the users in performing the desired motion while ensuring the motion stability of the overall system. This work describes the detailed design of the actuator followed by performance tests using a simple PD controller on the integrated robotic exoskeleton prototype. The performance of the proposed high level controller is tested using the integrated exoskeleton glove mechanism for a single finger, using two types of input motion. Preliminary results are discussed as well as plans for integrating the proposed actuator and high level controller into a complete hand exoskeleton prototype to perform intelligent grasping. © 2019 ASME.

关键词： Motion planning

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Microfluidic rheology to characterize viscoelastic properties of malignant and non-malignant epithelial cells 21

Microfluidic rheology to characterize viscoelastic propertie...

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21st International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2017

作者： Kim, Junghyun Sohn, Lydia L. Department of Mechanical Engineering University of California at Berkeley BerkeleyCA United States Graduate Program in Bioengineering University of California Berkeley University of California San Francisco BerkeleyCA United States

ISBN: (纸本)9780692941836

This study introduces a novel microfluidic rheology platform to quantify the viscoelastic properties of cells at the single-cell level. We measured both the storage (G') and loss (G") moduli of malignant and non-malignant epithelial cells, and simultaneously evaluate the frequency dependence of the moduli through a power-law structure damping model. With our unique platform's ability to screen large cellular populations, we have established a clear difference between the viscoelastic response of malignant and non-malignant cells. © 17CBMS-0001.

关键词： Cytology

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3D printing of functional polymers for miniature machines

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Multifunctional Materials 2022年第1期5卷

作者： Xia, Neng Jin, Dongdong Iacovacci, Veronica Zhang, Li Department of Mechanical and Automation Engineering The Chinese University of Hong Kong Hong Kong The BioRobotics Institute Scuola Superiore Sant’Anna Pisa56025 Italy Chow Yuk Ho Technology Center for Innovative Medicine Chinese University of Hong Kong Hong Kong CUHK T Stone Robotics Institute The Chinese University of Hong Kong Hong Kong Department of Surgery The Chinese University of Hong Kong Hong Kong

Miniature robots and actuators with micrometer or millimeter scale size can be driven by diverse power sources, e.g. chemical fuels, light, magnetic, and acoustic fields. These machines have the potential to access complex narrow spaces, execute medical tasks, perform environmental monitoring, and manipulate micro-objects. Recent advancements in 3D printing techniques have demonstrated great benefits in manufacturing small-scale structures such as customized design with programmable physical properties. Combining 3D printing methods, functional polymers, and active control strategies enables these miniature machines with diverse functionalities to broaden their potentials in medical applications. Herein, this review provides an overview of 3D printing techniques applicable for the fabrication of small-scale machines and printable functional materials, including shape-morphing materials, biomaterials, composite polymers, and self-healing polymers. Functions and applications of tiny robots and actuators fabricated by 3D printing and future perspectives toward small-scale intelligent machines are discussed. © 2022 IOP Publishing Ltd

关键词： Functional polymers

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Experimental Investigation of Lord Kelvin’s Isentropic Cooling and Heating Expression in Tensile Bars for Two engineering Alloys

arXiv

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arXiv 2023年

作者： Burns, S.J. Pratt, Christine E. Carrock, Joseph Gagnon, Jean-Philippe Sefkow, A.B. Materials Science Program College of Arts Science and Engineering University of Rochester RochesterNY14627 United States Department of Mechanical Engineering University of Rochester 236 Hopeman Hall RochesterNY14627 United States Field Application Engineering Telops GenevaNY14456 United States Systems Engineering Telops 100-2600 St-Jean-Baptiste Ave. QuébecQCG2E 6J5 Canada Laboratory for Laser Energetics University of Rochester 250 E. River Rd. RochesterNY14623 United States Department of Physics and Astronomy University of Rochester 206 Bausch and Lomb Hall RochesterNY14627 United States Department of Computer Science University of Rochester 2513 Wegmans Hall RochesterNY14627 United States

Solids when rapidly and elastically stressed change temperature, the effect proposed by Lord Kelvin is adiabatic thermo-elastic cooling or heating depending on the sign of the stress. A fast sensitive IR camera has measured temperature both decreasing and increasing. Temperature measurements made from the reversible, elastic part of the stress-strain curve during fast uniaxial tensile loading have been investigated. The isentropic temperature cooling from the loading curve is recovered by heating after the specimen fractures when the load is released. These measurements establish for the first time isentropic thermal recovery in two engineering alloys. The materials tested are an AISI 4340 steel and an aluminum 2024 alloy. Measurements of the isentropic thermo-elastic stress cooling are -0.61 K/GPa for steel and -1.7 K/GPa for aluminum alloy. The isentropic thermo-elastic stress heating is -1.16 K/GPa for steel and -1.6 K/GPa for aluminum alloy. These values are compared to Lord Kelvin’s theoretical thermodynamic prediction. Comparisons are also to equations of state tables. The experimental values are slightly below theoretical predictions. The isentropic, elastic part of the temperature is fully recoverable even after extensive plastic deformation upon fracture. Copyright © 2023, The Authors. All rights reserved.

关键词： Cooling

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A new approach to model constant curvature continuum robot dynamics

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ASME 2019 Dynamic Systems and Control Conference, DSCC 2019

作者： Liu, Yujiong Ben-Tzvi, Pinhas Robotics and Mechatronics Lab Department of Mechanical Engineering Virginia Tech BlacksburgVA24060 United States

ISBN: (纸本)9780791859162

Inspired by nature, continuum robots show their potential in human-centered environments due to the compliant-toobstacle features and dexterous mobility. However there are few such robots successfully implemented outside the laboratory so far. One reason is believed to be due to the real time control challenge for soft robots, which require a highly efficient, highly accurate dynamic model. This paper presents a new systematic methodology to formulate the dynamics of constant curvature continuum robots. The new approach builds on several new techniques: 1) using the virtual work principle to formulate the equation of motion, 2) using specifically selected kinematic representations to separate integral variables from the non-integral variables, and 3) using vector representations to put the integral in a compact form. By doing so, the hard-to-solve integrals are evaluated analytically in advance and the accurate inverse dynamics are established accordingly. Numerical simulations are conducted to evaluate the performances of the newly proposed model. © 2019 ASME.

关键词： Real time control

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Thermodegradation characterization of microplastics: Dispersion effect and pyrolysis kinetics by artificial intelligence

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Chemical engineering Journal 2023年第1期457卷

作者： Chen, Wei-Hsin Sun, Shih-Che Ocreto, Jherwin B. Nguyen, Thanh-Binh Lam, Su Shiung Park, Young-Kwon Dong, Cheng-Di Department of Aeronautics and Astronautics National Cheng Kung University Tainan701 Taiwan Research Center for Smart Sustainable Circular Economy Tunghai University Taichung407 Taiwan Department of Mechanical Engineering National Chin-Yi University of Technology Taichung411 Taiwan International Master Degree Program on Energy National Cheng Kung University Tainan701 Taiwan Department of Marine Environmental Engineering National Kaohsiung University of Science and Technology Kaohsiung City81157 Taiwan Universiti Malaysia Terengganu 21030 Kuala Nerus Terengganu Malaysia Johor Johor Bahru81310 Malaysia University Centre for Research and Development Department of Chemistry Chandigarh University Gharuan Punjab Mohali India School of Environmental Engineering University of Seoul Seoul02504 Korea Republic of

The research of pyrolytic thermodegradation of plastic wastes has received much attention. However, detailed combustion behavior and pyrolysis kinetics of microplastics are still absent in the current research. Understanding the characteristics and kinetics of microplastic pyrolysis is vital for designing and optimizing operational conditions. Adding silica to high-density polyethylene (HDPE) microplastics can effectively avoid the agglomeration of microplastics during pyrolysis, thereby better elucidating their thermodegradation. In the experiment, HDPE microplastics are mixed with SiO2 at different weight ratios (10 %, 20 %, 50 %, 70 %, and 100 %) to observe the dispersion effect on the microplastic thermodegradation. The results suggest that less than 20 % of PE in the mixture can retain microplastic pyrolysis characteristics. In combustion analysis, 10 % PE undergoes a faster thermo-oxidation reaction than pure HDPE. This study applies the independent parallel reaction (IPR) model and particle swarm optimization (PSO) algorithm to investigate microplastic pyrolysis kinetics. The pyrolysis activation energy is between 273.89 and 292.90 kJ‧mol−1, with fit quality high than 95 %, and rises with decreasing dispersion degree and increasing heating rate. This indicates that microplastic thermodegradation has low activation energy and is affected by heat transfer rate. The Py-GC/MS analysis indicates that up to 83.6 % of alkene and 52.3 % of products comprise high carbon numbers (17-Pentatriacontene and 1-Octatriacontene), respectively, suggesting the suppression of the secondary reaction of microplastics in the pyrolysis reaction. The calculated kinetic parameters are beneficial for understanding microplastic thermodegradation characteristics and can provide useful information for reactor design in industrial pyrolyzers or gasifiers. © 2023 Elsevier B.V.

关键词： Thermogravimetric analysis

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Single limb cable driven wearable robotic device for upper extremity movement support after traumatic brain injury

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Journal of Rehabilitation and Assistive Technologies engineering 2021年第8期8卷

作者： Kadivar, Zahra Beck, Christopher E Rovekamp, Roger N O’Malley, Marcia K Texas Institute for Rehabilitation and Research HoustonTX United States NASA JSC Wearable Robotics Laboratory HoustonTX United States Department of Mechanical Engineering Rice University HoustonTX United States

Introduction: Recently, soft exosuits have been proposed for upper limb movement assistance, most supporting single joint movements. We describe the design of a portable wearable robotic device (WRD), "Armstrong," able to support three degrees-of-freedom of arm movements, and report on its feasibility for movement support of individuals with hemiparesis after traumatic brain injury (TBI). Methods: We introduce Armstrong and report on a pilot evaluation with two male individuals post-TBI (T1 and T2) and two healthy individuals. Testing involved elbow flexion/extension with and without robotic-assisted shoulder stabilization;shoulder abduction with and without robotic-assisted elbow stabilization;and assisted shoulder abduction and flexion. Outcome measures included range of motion and root mean square trajectory and velocity errors. Results: TBI subjects performed active, passive, hybrid and active assistive movements with Armstrong. Subjects showed improvements in movement trajectory and velocity. T1 benefited from hybrid, active, and assistive modes due to upper extremity weakness and muscle tone. T2 benefited from hybrid and assistive modes due to impaired coordination. Healthy subjects performed isolated movements of shoulder and elbow with minimal trajectory and velocity errors. Conclusions: This study demonstrates the safety and feasibility of Armstrong for upper extremity movement assistance for individuals with TBI, with therapist supervision. © The Author(s) 2021.

关键词： Stabilization

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Development of augmented reality-based medical intervention system by ultrasound image calibration technique

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Journal of Institute of Control, robotics and Systems 2019年第7期25卷 610-616页

作者： Kim, Tae-Ho Park, Hae-June Baek, Jun-Min Kim, Sung-Min Lee, Jeh-Won Seo, Joon-Ho School of Mechanical Engineering Kyungpook National University Korea Republic of School of Electronics Engineering Kyungpook National University Korea Republic of Korea Institute of Machinery and Materials Korea Republic of Department of Robotics Yeungnam University Korea Republic of

In a conventional ultrasound image-based biopsy procedure, the needle is inserted alternately between the patient’s body and the ultrasound imaging system;doing so requires a considerable amount of training to ensure accuracy. In this study, we developed an augmented reality-based ultrasound image intervention system that enables the simultaneous viewing of ultrasound images and the patient’s body in the same direction for a more-intuitive ultrasound-based biopsy. For an intuitive biopsy, the correlation between an ultrasound-guided breast biopsy phantom and the ultrasound image was visualized by overlapping ultrasound images with real-time images. In addition, the matching accuracy of the real objects and the augmented images was improved by 76% as compared to the previous system through ultrasound image calibration, and the idea of the proposed augmented reality-based ultrasound image intervention procedure system was verified. © ICROS 2019.

关键词： Phantoms

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Improved lattice Boltzmann model for immiscible multicomponent systems with high viscosity gradients at the interface

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Physical Review E 2024年第1期110卷 015303-015303页

作者： Ricardo L. M. Bazarin Christian Naaktgeboren Silvio L. M. Junqueira Paulo Cesar Philippi Luiz Adolfo Hegele, Jr. Porous Media Research Group (PORO) Scientific Computational Laboratory <a href="https://***/041akq887">Federal University of Santa Catarina</a> 89219-600 Joinville SC Brazil. Hermann von Helmholtz Energy Research Group <a href="https://***/002v2kq79">Federal University of Technology</a> Av. Guarapuava 800. Cidade dos Lagos 85053-525 Guarapuava PR Brazil. Research Center for Rheology and Non-Newtonian Fluids <a href="https://***/002v2kq79">Federal University of Technology</a> 81280-340 R. Deputado Heitor Alencar Furtado 5000 - Bloco N - Ecoville Curitiba PR Brazil. Mechanical Engineering Graduate Program <a href="https://***/02x1vjk79">Pontifical Catholic University of Parana</a> 80215-901 Curitiba PR Brazil. Department of Petroleum Engineering <a href="https://***/03ztsbk67">Santa Catarina State University</a> 88336-275 Balneário Camboriú SC Brazil.

We propose alternative discretization schemes for improving the lattice Boltzmann pseudopotential model for incompressible multicomponent systems, with the purpose of modeling the flow of immiscible fluids with a large viscosity ratio. Compared to the original model of Shan-Chen [Phys. Rev. E 47, 1815 (1993)], the present discretization schemes consider: (i) an explicit force term, (ii) a second-order discretization of the stream term, (iii) a moments-based model for the kinetic nonequilibrium distributions, and (iv) a high-order discretization of the spatial derivative terms. To verify the accuracy of the proposed model, the effects of varying the viscosity ratio as well as both fluid's viscosities on spurious currents and capillary number are investigated for the problems dealing with a static bubble, two-component Poiseuille flow, and immiscible fluid-fluid displacement. The resulting algorithm maintains the simplicity of the pseudopotential model while allowing an easy implementation for multicomponent systems. The results of the model herein proposed show improved control of the interface region and interfacial tension, relatively smaller magnitudes of spurious current values with increasing viscosity ratio, and also a significantly wider stability range with respect to the previously best results in the literature.

关键词： Displacement of immiscible fluids Surface tension effects Multiphase flows Lattice-Boltzmann methods

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Society 5.0 competency: Readiness level of teachers and students in automotive engineering vocational school

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AIP Conference Proceedings 2023年第1期2671卷

作者： Hamid Ramadhan Nur Zainal Arifin Soeryanto Farid Mutohhari Rihab Wit Daryono 1Postgraduated Program Technology and Vocational Education Universitas Negeri Yogyakarta Indonesia 2Department Mechanical Engineering Engineering Faculty Surabaya State University Indonesia

This study aims to analyze the level of readiness of automotive engineering teachers and students in mastering the competence of society 5.0 *** school. The survey research uses a design developed by Rea & Parker. A total of 185 students and 80 teachers automotive engineering from 5 vocational high schools in the Sleman district were involved as research samples. Data were collected using a questionnaire technique with a Likert scale questionnaire instrument. The accumulated data were analyzed using descriptive statistics and inferential statistics t-test. Society 5.0 competency is based on 6 aspects, namely critical thinking and problem solving, communication and collaboration, creativity and innovation, digital literacy, flexibility and adaptability, and leadership and responsibility. The results showed that the level of readiness of automotive engineering students in mastering society 5.0 competency obtained 67.341% for public students and 64.510% for private students. Meanwhile, the level of automotive engineering teacher readiness was 72.243% for public teachers and 68.400% for private teachers. While the t-test obtained t-value>t-table and sign. (p <0.05) states that there are differences in the level of readiness of teachers and students in both public and private schools in mastering the society 5.0 competency. So that the readiness of students and teachers in mastering society 5.0 competency is categorized as high. Various training and learning innovations that are relevant to society 5.0 competency need to be improved.

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