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Auto-tuning control of pem water electrolyzer

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ASME 2019 Dynamic Systems and Control Conference, DSCC 2019

作者： Keow, Alicia Chen, Zheng Bio-inspired Robotics and Controls Lab Department of Mechanical Engineering University of Houston HoustonTX77204 United States

ISBN: (纸本)9780791859155

Proton exchange membrane (PEM) electrolyzers with theability to produce gases at a pressure suitable for direct metal hydride storage are desirable because they do not require the use ofcompressors and other auxiliary components. Direct storage intometal hydride cylinders is made feasible when the pressure andflow rate of hydrogen is controlled. The nonlinear dynamics ofthe PEM electrolyzer change with temperature and pressure, bothof which change with the hydrogen production rate, and are thusdifficult to estimate. Therefore, a model-free, relay-feedback,auto-tuning approach is used to tune a proportional integral (PI)controller. This allows for the determination of the voltage supply to the electrolyzer by tracking the current set-point and correlating it to the hydrogen production rate. A gain schedulingapproach is used to record the tuned controller's parameters atdifferent set-points, minimizing the frequency of tuning the device. A self-assessment test is used to determine situations wherethe auto-tuner should activate to update the PI parameters, thus,allowing for the system to operate without supervision. The autotuning PI control is successfully tested with a PEM electrolyzersetup. Experimental results showed that an auto-tuner can tunethe controller parameters and produce favorable transient behaviors, allowing for a degree of adaptability for variations in systemset-points. Copyright © 2019 ASME.

关键词： Hydrogen production

Composite Adaptive Control for Anti-Unwinding Attitude Maneuvers: An Exponential Stability Result without Persistent Excitation

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arXiv 2021年

作者： Shao, Xiaodong Hu, Qinglei Li, Daochun Shi, Yang Yi, Bowen School of Aeronautic Science and Engineering Beihang University Beijing100191 China School of Automation Science and Electrical Engineering Beihang University Beijing100191 China Department of Mechanical Engineering University of Victoria VictoriaBCV8N 3P6 Canada Australian Center for Field Robotics University of Sydney SydneyNSW2006 Australia

This paper provides an exponential stability result for the adaptive anti-unwinding attitude tracking control problem of a rigid body with uncertain but constant inertia parameters, without requiring the satisfaction of persistent excitation (PE) condition. Specifically, a composite immersion and invariance (I&I) adaptive controller is derived by integrating a prediction-error-driven learning law into the dynamically scaled I&I adaptive control framework, wherein we modify the scaling factor so that the algorithm design does not involve any dynamic gains. To avoid the unwinding problem, a barrier function is introduced as the attitude error function, along with the tactful establishment of two crucial algebra properties for exponential stability analysis. The regressor filtering method is adopted in combination with the dynamic regressor extension and mixing (DREM) procedure to acquire the prediction error using only easily obtainable signals. In particular, aiding by a constructive liner time-varying filter, the scalar regressor of DREM is extended to generate a new exciting counterpart. In this way, the derived controller is shown to permit closed-loop exponential stability without PE, in the sense that both output-tracking and parameter estimation errors exponentially converge to zero. Further, the composite learning law is augmented with a power term to achieve synchronized finite/fixed-time parameter convergence. Numerical simulations are performed to verify the theoretical findings. © 2021, CC BY.

关键词： Navigation

Compositionally Complex Perovskite Oxides for Solar Thermochemical Water Splitting

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arXiv 2022年

作者： Zhang, Dawei De Santiago, Héctor A. Xu, Boyuan Liu, Cijie Trindell, Jamie Li, Wei Park, Jiyun Rodriguez, Mark A. Coker, Eric N. Sugar, Josh McDaniel, Anthony Lany, Stephan Ma, Liang Wang, Yi Collins, Gregory Tian, Hanchen Li, Wenyuan Qi, Yue Liu, Xingbo Luo, Jian Program of Materials Science and Engineering University of California San Diego La Jolla CA92093 United States Department of Mechanical and Aerospace Engineering Benjamin M. Statler College of Engineering and Mineral Resources West Virginia University MorgantownWV26506 United States Department of Physics Brown University ProvidenceRI02912 United States Sandia National Laboratories LivermoreCA94551 United States School of Engineering Brown University ProvidenceRI02912 United States Sandia National Laboratories AlbuquerqueNM87185 United States Materials Science Center National Renewable Energy Laboratory GoldenCO80401 United States School of Materials Science and Engineering Hebei University of Engineering Hebei Province Handan056038 China Department of Chemical and Biomedical Engineering Benjamin M. Statler College of Engineering and Mineral Resources West Virginia University MorgantownWV26506 United States Department of NanoEngineering University of California San Diego La Jolla CA92093 United States

Solar thermochemical hydrogen generation (STCH) is a promising approach for eco-friendly H2 production, but conventional STCH redox compounds often suffer from thermodynamic and kinetic limitations with limited tunability. Expanding from the nascent high-entropy ceramics field, this study explores a new class of compositionally complex perovskite oxides (La0.8Sr0.2)(Mn(1-x)/3Fe(1-x)/3CoxAl(1-x)/3)O3 for STCH. In situ X-ray diffraction demonstrates the phase stability during redox cycling and in situ X-ray photoelectron spectroscopy shows preferential redox of Co. The extent of reduction increases, but the intrinsic kinetics decreases, with increased Co content. Consequently, (La0.8Sr0.2)(Mn0.2Fe0.2Co0.4Al0.2)O3-δ achieves an optimal balance between the thermodynamics and kinetics properties. The combination of a moderate enthalpy of reduction, high entropy of reduction, and preferable surface oxygen exchange kinetics enables a maximum H2 yield of 395 ± 11 μmol g-1 in a short 1-hour redox duration. Entropy stabilization expectedly contributes to the structure stability during redox without phase transformation, which enables an exceptional STCH stability for >50 cycles under harsh interrupted conditions. The underlying redox mechanism is further elucidated by the density functional theory based parallel Monte Carlo computation, which represents a new computation paradigm first established here. This study suggests a new class of non-equimolar compositionally complex ceramics for STCH and chemical looping. © 2022, CC BY.

关键词： Entropy

Experimental Investigation to Utilize Adsorption and Absorption Technique to Reduce CO2 Emissions in Diesel Engine Exhaust Using Amine Solutions

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Adsorption Science & Technology 2022年 2022卷

作者： Solomon Jenoris Muthiya L. Natrayan S. Kaliappan Pravin P. Patil B. E. Naveena Joshuva Arockia Dhanraj Mohankumar Subramaniam Prabhu Paramasivam Department of Automobile Engineering Dayananda Sagar College of Engineering Bengaluru 560078 India Department of Mechanical Engineering Saveetha School of Engineering SIMATS Chennai 602105 Tamil Nadu India Department of Mechanical Engineering Velammal Institute of Technology Chennai Tamil Nadu India Department of Mechanical Engineering Graphic Era Deemed to Be University Bell Road Clement Town 248002 Dehradun Uttarakhand India Center for Automation and Robotics (ANRO) Department of Mechanical Engineering Hindustan Institute of Technology and Science Padur Chennai 603103 India Department of Automobile Engineering Kumaraguru College of Technology Coimbatore 641006 India Department of Mechanical Engineering College of Engineering and Technology Mettu University 318 Ethiopia

Due to the increased demand for global transportation needs, a long-range diesel engine is considered an important prime mover to fulfill the transportation demand. The major problem addressed by the diesel engines is it liberates harmful emissions and it also increases global warming. CO2 is considered an important greenhouse gas and it has to be controlled by diesel engines. In this research, extensive experimental work is done to identify a suitable solution to control CO2 emissions. For five different mole concentrations (0.1 to 0.5), three types of amino solutions (L-alanine, L-aspartic acid, and L-arginine) were prepared. By passing diesel exhaust through each solution, CO2 absorption is investigated. For CO2 absorption, an appropriate CO2 control system is built and tested. The tests were carried out in a diesel engine which is a naturally aspirated single-cylinder engine with a water-cooled system. It was possible to obtain an effective CO2 reduction of up to 90%, as well as a simultaneous reduction in HC and CO.

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iCub3 Avatar System: Enabling Remote Fully-Immersive Embodiment of Humanoid Robots

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arXiv 2022年

作者： Dafarra, Stefano Pattacini, Ugo Romualdi, Giulio Rapetti, Lorenzo Grieco, Riccardo Darvish, Kourosh Milani, Gianluca Valli, Enrico Sorrentino, Ines Viceconte, Paolo Maria Scalzo, Alessandro Traversaro, Silvio Sartore, Carlotta Elobaid, Mohamed Guedelha, Nuno Herron, Connor Leonessa, Alexander Draicchio, Francesco Metta, Giorgio Maggiali, Marco Pucci, Daniele Artificial and Mechanical Intelligence Istituto Italiano di Tecnologia Genoa Italy iCub Tech Facility Istituto Italiano di Tecnologia Genoa Italy School of Computer Science University of Manchester Manchester United Kingdom DIAG Sapienza Università di Roma Rome Italy Department of Mechanical Engineering Virginia Tech BlacksburgVA United States Computer Science and Robotics Institute University of Toronto Toronto Canada Rome Italy

We present an avatar system designed to facilitate the embodiment of humanoid robots by human operators, validated through iCub3, a humanoid developed at the Istituto Italiano di Tecnologia (IIT). More precisely, the contribution of the paper is twofold: first, we present the humanoid iCub3 as a robotic avatar which integrates the latest significant improvements after about fifteen years of development of the iCub series;second, we present a versatile avatar system enabling humans to embody humanoid robots encompassing aspects such as locomotion, manipulation, voice, and face expressions with comprehensive sensory feedback including visual, auditory, haptic, weight, and touch modalities. We validate the system by implementing several avatar architecture instances, each tailored to specific requirements. First, we evaluated the optimized architecture for verbal, non-verbal, and physical interactions with a remote recipient. This testing involved the operator in Genoa and the avatar in the Biennale di Venezia, Venice – about 290 Km away – thus allowing the operator to visit remotely the Italian art exhibition. Second, we evaluated the optimised architecture for recipient physical collaboration and public engagement on-stage, live, at the We Make Future show, a prominent world digital innovation festival. In this instance, the operator was situated in Genoa while the avatar operates in Rimini – about 300 Km away – interacting with a recipient who entrusted the avatar a payload to carry on stage before an audience of approximately 2000 spectators. Third, we present the architecture implemented by the iCub Team for the ANA Avatar XPrize competition. Copyright © 2022, The Authors. All rights reserved.

关键词： Anthropomorphic robots

Modelling and Dynamic Analysis of a Novel Hybrid Aerial - Underwater Robot - Acutus

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Modelling and Dynamic Analysis of a Novel Hybrid Aerial - Un...

2019 OCEANS - Marseille, OCEANS Marseille 2019

作者： Vyas, Abhijeet Puppala, Ridhi Sivadasan, Nikhil Molawade, Akshay Ranganathan, Thiyagarajan Thondiyath, Asokan Department of Mechanical Engineering Indian Institute of Technology Madras India Robotics Laboratory Indian Institute of Technology Madras India

ISBN: (纸本)9781728114507

Hybrid multi domain vehicles are of great interest in due to their ability to traverse between different medium. The objective behind developing such hybrid vehicle/robot is to combine the capabilities of systems operating in various domains. Very few vehicles are presently being developed which can traverse underwater and can fly in air. Development of systems with capability to traverse both in air and water is highly challenging because of the contrasting properties of the traversing domains. In this paper, we propose one such vehicle which can be used as a remotely operated vehicle (ROV) underwater and can fly as a quadrotor. Design of such system is critical, as the dimensions and other related parameters like the mass and volume has to be optimal for both aerial and underwater traversal. Hence the system mathematically modelled to analyze the dynamics of the system and the same has been used to optimize the dimensions and the overall performance of the result. This paper presents the detailed design, mathematical model of the system and the preliminary simulation results using the developed model. An experimental prototype is being developed to analyze and validate the concept. © 2019 IEEE.

关键词： Antennas

Gait Analysis of Multi-Step Climbing Active Wheeled Snake Robot 4

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Gait Analysis of Multi-Step Climbing Active Wheeled Snake Ro...

4th International Conference on robotics and Automation engineering, ICRAE 2019

作者： Sahu, Divyanshu Kodi, Ramachandra Singh, Sartaj Institute of Technology Nirma University Department of Mechanical Engineering Ahmedabad India Intelligent Systems and Robotics Division Bangalore India

ISBN: (纸本)9781728147406

Snake robots have been a popular choice for search and rescue operations in disaster-prone areas, cramped spaces, uneven terrain and in hazardous environments unfit for humans due to their flexibility, modular design and highly articulated body structure. One of the salient features required by these robots is the ability to climb multiple steps at a time. Inspired by biological snakes which can seamlessly change their shape according to the contour of stairs for climbing multiple steps, this paper proposes a 'Step Morphing Gait' which would enable the proposed snake robot design to ascend multiple steps at a time. Gait analysis in this paper shows the step by step procedure of how the gait is implemented. Also, a looping technique in this gait is developed which makes the problem of climbing multiple steps for hyper redundant systems intuitively easier to understand and implement in realtime simulated environment. Co-simulation results validate the proposed gait. © 2019 IEEE.

关键词： Gait analysis

Bayesian estimation of snow-avalanche victim pose: A method to assist human and/or robot first responders to quickly locate a buried victim

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ASME 2019 Dynamic Systems and Control Conference, DSCC 2019

作者： Bourne, Joseph R. Leang, Kam K. Lab Department of Mechanical Engineering Robotics Center University of Utah Salt Lake CityUT84112 United States

ISBN: (纸本)9780791859162

Finding a victim buried in a snow avalanche as quickly as possible can significantly increase the victim's survival rate. A body-pose estimation algorithm is described that quickly and efficiently estimates the victim's pose (3D location and orientation) underneath the snow. The algorithm exploits non-parametric Bayesian estimation and considers the uncertainty in an avalanche transceiver's magnetic-field measurement. Simulation results compare the performances between three victim-search methods: (1) naive raster-scanning search, (2) traditional industry-standard search along the measured magnetic field lines, and (3) search by the Bayesian-based technique. The results show that the Bayesianbased technique accurately determines the victim's pose within two minutes. In contrast, the raster-scanning and magnetic-field-line following methods yield search times more than three to four times longer. © 2019 ASME.

关键词： Bayesian networks

Passive sub-ambient cooling: radiative cooling versus evaporative cooling

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arXiv 2021年

作者： Aili, Ablimit Yin, Xiaobo Yang, Ronggui Department of Mechanical Engineering University of Colorado BoulderCO80309 United States Materials Science and Engineering Program University of Colorado BoulderCO80309 United States State Key Laboratory of Coal Combustion School of Energy and Power Engineering Huazhong University of Science and Technology Hubei Wuhan430074 China

Day-and-night radiative sky cooling has emerged as a potential alternative to conventional cooling technologies such as refrigeration-based air conditioning and evaporative wet cooling. Both radiative cooling and evaporative cooling can passively achieve sub-ambient cooling without consuming electricity. Although both cooling techniques are subject to impacts from various weather conditions, the extents of the impacts under the same conditions are not well understood. In this work, we experimentally and theoretically study the thermal performances of a passive radiative cooler and a passive evaporative cooler when exposed to a clear night sky. We show that evaporative cooling is better suited for high-temperature and low-humidity weather conditions, with the measured sub-ambient temperatures of the radiative and evaporative coolers being −13.5℃ and −15.0℃, respectively, at a low relative humidity of 13% and a high ambient temperature of 26.0℃. On the other hand, radiative cooling is relatively more resilient than evaporative cooling under high-humidity and/or low-temperature weather conditions, with the measured subambient temperatures of the coolers being −11.5℃ and −10.5℃, respectively, at a slightly higher relative humidity of 32.0% and a slightly lower ambient temperature of 17.0℃. Depending on water availability and weather conditions, both evaporative cooling and radiative cooling can be adopted as mutually supplemental cooling technologies. © 2021, CC BY-SA.

关键词： Evaporation