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A Nonlinear MPC-Net Optimization Framework for Wheeled Humanoid Robots with Whole Body Dynamics

IEEE Transactions on Automation Science and engineering 2025年

作者： Li, Guoxin Liu, Xingjian Wu, Xiaoyu Tang, Qirong Zhang, Hao Li, Zhijun Shi, Peng Tongji University School of Mechanical Engineering Translational Research Center Shanghai YangZhi Rehabilitation Hospital Shanghai Sunshine Rehabilitation Center Shanghai200092 China Shanghai Key Laboratory of Wearable Robotics and Human-Machine Interaction Shanghai201804 China State Key Laboratory of High-Performance Precision Manufacturing Dalian116024 China Tongji University School of Mechanical Engineering Shanghai201804 China National University of Singapore Department of Biomedical Engineering 117583 Singapore Tongji University Department of Control Science and Engineering Shanghai201804 China The University of Adelaide School of Electrical and Mechanical Engineering SA5005 Australia Obuda University Budapest1034 Hungary

The task performance of mobile manipulators can be significantly enhanced by whole-body control and optimization in complex scenarios. Due to the nonlinear properties of whole-body dynamics and parameter uncertainty, modeling accurate system dynamics is essential in addition to designing an effective control strategy. However, traditional control methods have high computational costs and fail to deal with the parameter errors caused by model linearization. To address these issues, we propose a model predictive control (MPC)-Net, a learning-based approach that facilitates rapid online optimization by combining deep learning with multiple MPCs. Firstly, we develop a parameter identification algorithm based on a deep neural model to estimate the unknown dynamics parameters. Although the control performance of the MPC approach positively correlated with the prediction horizon, a long horizon would result in additional computational costs. Thus, MPC-Net is constructed by combining multiple sub-MPC issues, and the nonlinear coefficients are obtained by using a deep neural network-based optimization framework. Furthermore, MPC-Net generates the solution by combining the outputs of multiple sub-MPC problems using the nonlinear transformation of learned coefficients. Experiments are conducted on a mobile manipulator, which demonstrates the proposed MPC-Net-based optimization control offers fast efficient computation and low tracking error performance. © 2004-2012 IEEE.

关键词： Predictive control systems

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A comprehensive evaluation of the use of graphene enriched cutting fluids on the surface integrity of very poor-grindability materials

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Wear 2025年

作者： de Oliveira, Déborah de Paiva, Raphael Lima de Souza Ruzzi, Rodrigo Jackson, Mark James Gelamo, Rogério Valentim Machado, Alisson Rocha da Silva, Rosemar Batista University of Brasília Department of Mechanical Engineering DF Brasília Brazil Federal University of Piauí School of Mechanical Engineering PI Teresina Brazil Federal University of Uberlandia School of Mechanical Engineering MG Uberlandia Brazil Kansas State University College of Technology and Aviation SalinaKS United States Federal University of Triângulo Mineiro Institute of Technological and Exact Sciences MG Uberaba Brazil Pontifícia Universidade Católica do Paraná Mechanical Engineering Graduate Program PR Curitiba Brazil

The use of graphene has stood out in recent years in different fields due to the wide applicability based on its properties. Specifically, multilayer graphene can be highlighted as a good lubricant, it possesses low shear resistance between layers and has good thermal conductivity. Those characteristics are well suitable for cutting fluids, especially considering the grinding process which presents high friction, elastic and plastic deformations, and the intense occurrence of plowing, thereby resulting in high specific cutting energy. However, studies have shown the use of graphene on cutting fluids can be influenced by many factors, including delivery methods, particle concentrations and even the workpiece material. Thus, a comprehension of how graphene particles added to the cutting fluid interact at the abrasive-chip interface is important for its correct use and the achievement of high-quality surfaces. In this sense, this work aims to investigate the use of multilayer graphene enhanced cutting fluids delivered during the grinding process for three different very poor-grindability materials: Inconel 625, Inconel 718 and SAE 52100 hardened steel. Different multilayer graphene concentrations (0.05–0.1 wt%) were added in the same base fluid and tested under different flow rates. The influence of graphene was assessed in terms of grinding power, surface roughness and morphology (SEM images). The experimental results showed that for the lower hardness material (Inconel 625), graphene promoted intense plowing and adhered material on the ground surface, while for the SAE 52100 steel, minor effects were generated on the surface affecting its integrity. For Inconel 718, that possesses both high hardness and ductile responses, the presence of graphene in the cutting fluid provides a great improvement in cutting, resulting in 15 % and 27 % reduction in surface roughness values and grinding power, respectively, even for a low cutting fluid flow rate. © 2025 Elsevier B.V.

关键词： Grinding (machining)

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Effects of Uni- and Bidirectional Interaction During Dyadic Ankle and Wrist Tracking

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IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE engineering in Medicine and Biology Society 2025年 PP卷 PP页

作者： Matthew R Short Daniel Ludvig Francesco Di Tommaso Lorenzo Vianello Emek Baris Kucuktabak Eric J Perreault Levi Hargrove Kevin Lynch Etienne Burdet Jose L Pons Shirley Ryan AbilityLab Chicago IL USA Department of Biomedical Engineering Northwestern University Evanston IL USA Department of Physical Medicine and Rehabilitation Northwestern University Chicago IL USA Departmental Faculty of Engineering Università Campus Bio-Medico di Roma Rome Italy Department of Mechanical Engineering Northwestern University Evanston IL USA Center for Robotics and Biosystems Evanston IL USA Department of Bioengineering Imperial College of Science Technology and Medicine London U.K.

Haptic human-robot-human interaction allows users to feel and respond to one another's forces while interfacing with separate robotic devices, providing customizable infrastructure for studying physical interaction during motor tasks (e.g., physical rehabilitation). For upper- and lower-limb tracking tasks, previous work has shown that virtual interactions with a partner can improve motor performance depending on the skill level of each partner. However, whether the mechanism explaining these improvements is identical in the upper and lower limbs is an open question. In this work, we investigate the effects of haptic interaction between healthy individuals during a trajectory tracking task involving single-joint movements at the wrist and ankle. We compare tracking performance and muscle activation during haptic conditions where pairs of participants were uni- and bidirectionally connected to investigate the contribution of real-time responses from a partner during the interaction. Findings showed similar improvements in tracking performance during bidirectional interaction for both the wrist and ankle. This was observed despite distinct strategies in muscle co-contraction between joints, as co-contraction was dependent on partner ability for the wrist but not the ankle. For each joint, bidirectional and unidirectional interaction resulted in similar improvements for the worse partner in the dyad. For the better partner, bidirectional interaction resulted in greater improvements than unidirectional interaction. While these results suggest that unidirectional interaction is sufficient for error correction of less skilled individuals during simple motor tasks, they also highlight the mutual benefits of bidirectional interaction which are consistent across the upper and lower limbs.

关键词： Robots Ankle Robot sensing systems Wrist Haptic interfaces Trajectory Motors Training Torque Muscles

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Operational Efficiency of Synchronous Reluctance Generator Systems using Vector Control

Operational Efficiency of Synchronous Reluctance Generator S...

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International Electrical engineering Congress (iEECON)

作者： Ryunosuke Hayashi Wataru Kitagawa Takaharu Takeshita Azusa Takahashi Tatsuya Higashi Creative Engineering Education Program Nagoya Institute of Technology Nagoya Japan Department of Electrical and Mechanical Engineering Nagoya Institute of Technology Nagoya Japan Departmnt of Electrical and Mechanical Engineering Nagoya Institute of Technology Nagoya Japan Mobility Development Group DAIHATSU MOTOR CO. LTD. Osaka Japan

ISBN: (数字)9798331543952

ISBN: (纸本)9798331543969

This study aims to verify the operation of a system that combines a generator, an inverter to control it, and a power conditioner, as well as to observe the system efficiency at the theoretical MTPA (Maximum Torque Per Ampere) point. The generator is driven by vector control with a rated output of 12 kW, and the inverter has a capacity of 47 kW.

关键词： Electrical engineering Torque Inverters Generators Reluctance generators

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Energy injection in an epithelial cell monolayer via negative viscosity

arXiv

引用

arXiv 2025年

作者： McCord, Molly Notbohm, Jacob Department of Mechanical Engineering University of Wisconsin-Madison MadisonWI United States Biophysics Program University of Wisconsin-Madison MadisonWI United States

Active fluids are driven out of thermodynamic equilibrium by internally generated forces, causing complex patterns of motion. Even when both the forces and motion are measurable, it is not yet possible to relate the two, because the sources of energy injection and dissipation are often unclear. Here, we study how energy is transferred by developing a method to measure viscosity from the shear stresses and strain rates within an epithelial cell monolayer. Surprisingly, there emerged multicellular regions in which the relationship between shear stress and shear strain rate was negatively proportional, indicating a negative viscosity. We provide direct experimental evidence that the negative viscosity results from cells aligning their stresses with the orientation of the flow. Regions of negative viscosity consistently exhibited greater cell speed and vorticity, and the cells had elevated metabolic activity, indicating that negative viscosity is a mechanism for injection of surplus energy. More broadly, our study shows that negative viscosity is a useful means of quantifying the flow of energy in active materials. Copyright © 2025, The Authors. All rights reserved.

关键词： Shear stress

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Effective Dimension Aware Fractional-Order Stochastic Gradient Descent for Convex Optimization Problems

arXiv

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arXiv 2025年

作者： Partohaghighi, Mohammad Marcia, Roummel Chen, YangQuan Electrical Engineering and Computer Science graduate program University of California Merced United States Department of Applied Mathematics University of California Merced MercedCA United States Lab Department of Mechanical Engineering School of Engineering University of California MercedCA95343 United States

Fractional-order stochastic gradient descent (FOSGD) leverages a fractional exponent to capture long-memory effects in optimization, yet its practical impact is often constrained by the difficulty of tuning and stabilizing this exponent. In this work, we introduce 2SED Fractional-Order Stochastic Gradient Descent (2SEDFOSGD), a novel method that synergistically combines the Two-Scale Effective Dimension (2SED) algorithm with FOSGD to automatically calibrate the fractional exponent in a data-driven manner. By continuously gauging model sensitivity and effective dimensionality, 2SED dynamically adjusts the exponent to curb erratic oscillations and enhance convergence rates. Theoretically, we demonstrate how this dimension-aware adaptation retains the benefits of fractional memory while averting the sluggish or unstable behaviors frequently observed in naive fractional SGD. Empirical evaluations across multiple benchmarks confirm that our 2SED-driven fractional exponent approach not only converges faster but also achieves more robust final performance, suggesting broad applicability for fractional-order methodologies in large-scale machine learning and related domains. © 2025, CC BY.

关键词： Convex optimization

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Single-Axis Solar Tracking Systems: A Comprehensive Design and Performance Study

引用

Procedia Computer Science 2025年 253卷 2740-2752页

作者： M.O. Okwu O.P. Eruero N. Abubakar B.A. Edward B.U. Oreko O.B. Otanocha O.F. Orikpete C. Maware K.C. Ezekiel C. Ori L. Tartibu Department of Mechanical Engineering Federal University of Petroleum Resources Effurun Nigeria Computer Science Department Brunel University London Uxbridge UB8 3PH United Kingdom Centre for Occupational Health Safety and Environment (COHSE) University of Port Harcourt Choba Nigeria Fujio Cho Engineering Technology 210E Center for Robotics and Manufacturing Building University of Kentucky USA Maintenance Engineering and Asset Management University of Manchester United Kingdom 814-131 Wentworth Drive Halifax Nova Scotia Canada Department of Mechanical and Industrial Engineering Technology University of Johannesburg South Africa

Abundant solar resources and increasing electricity demand make solar energy a promising renewable energy source in Sub-Saharan Africa. However, conventional stationary Photovoltaic (PV) systems face challenges in efficiently capturing solar irradiation. To address this limitation, the implementation of solar tracking systems becomes essential, as they optimize the energy output of PV systems by dynamically adjusting the orientation of the panels to align with the sun’s rays. This study presents a comprehensive design and performance evaluation of single-axis solar tracking systems in Delta State, Nigeria. The investigation focused on the energy provision efficiency of these systems, revealing that the single-axis tracker reached peak performance at year-end, providing 9.333 kWh of available solar energy and 9.296 kWh of user-available energy. Over the year, the system delivered a total of 100.625 kWh of available solar energy and 96.483 kWh of user-available energy. These findings highlight the significant role of solar tracking systems in maximizing energy harvest and underscore their potential for improving energy sustainability in Sub-Saharan Africa.

关键词： Solar Energy Photovoltaic Systems Solar Tracking Renewable Energy Energy Efficiency Photovoltaic System

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Gesture vs. Touch Control for Unforeseen Situations of Human-Robot Collaborative Assembly 25

Gesture vs. Touch Control for Unforeseen Situations of Human...

引用

ACM/IEEE International Conference on Human-Robot Interaction (HRI)

作者： Philipp Kranz Dennis Kristhofen Fabian Schirmer Chad G. Rose Jan Schmitt Tobias Kaupp Center for Robotics (CERI) Technical University of Applied Sciences Würzburg-Schweinfurt Germany Department of Mechanical Engineering Auburn University Auburn Alabama USA Institute Digital Engineering (IDEE) Technical University of Applied Sciences Würzburg-Schweinfurt Germany

ISBN: (数字)9798350378931

ISBN: (纸本)9798350378948

This study examines the efficacy of gesture-based versus touch-based control interfaces in managing unanticipated scenarios in human-robot collaborative assembly (HRCA). As collaborative robots (cobots) become increasingly integrated into industrial environments, there is a need for control interfaces that enable workers to respond to unanticipated deviations from the assembly process. Such control interfaces must be intuitive to use, acceptable to the worker, and not result in an increased workload. We conducted a controlled experiment with 30 participants, comparing the performance of gesture-based against touch-based control interfaces in an assembly task, which included simulated disruptions. Workload was evaluated using the NASA Task Load Index (NASA-TLX), and acceptance via a Technology Acceptance Model (TAM), adapted for HRCA. The results demonstrate no statistically significant differences between the two measures. However, they indicate that touch control results in a lower workload and higher user acceptance, which may be attributed to users' familiarity with touch interfaces.

关键词： Technology acceptance model Atmospheric measurements NASA Human-robot interaction Process control Collaborative robots Particle measurements Indexes Assembly

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Utilizing Eye Gaze for Human-Robot Collaborative Assembly 25

Utilizing Eye Gaze for Human-Robot Collaborative Assembly

引用

ACM/IEEE International Conference on Human-Robot Interaction (HRI)

作者： Fabian Schirmer Philipp Kranz Chad G. Rose Volker Willert Jan Schmitt Tobias Kaupp Center for Robotics (CERI) Technical University of Applied Sciences Würzburg-Schweinfurt Germany Department of Mechanical Engineering Auburn University Auburn Alabama USA Institute Digital Engineering (IDEE) Technical University of Applied Sciences Würzburg-Schweinfurt Germany

ISBN: (数字)9798350378931

ISBN: (纸本)9798350378948

Human-Robot Collaboration (HRC) in dynamic assembly environments requires intuitive communication for seamless interactions. Eye gaze, a nonverbal cue, is critical for interpreting human intent and enhancing robot adaptability. This research introduces a three-tier framework categorizing eye gaze into fixation, scanning, and task-switching behaviors, aiming to improve real-time robot responsiveness. Preliminary evaluations with multiple human subjects demonstrated the potential of this classification to enhance task alignment and detect anomalies in human behavior. Future work will explore automated personalization of the algorithm for individuals and integrate multimodal data to refine adaptability in human-robot collaborative systems.

关键词： Human-robot interaction Collaboration Real-time systems Classification algorithms Behavioral sciences Robots Assembly

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Spatio-temporal characterization of nonlinear forcing and response in turbulent channel flow

arXiv

引用

arXiv 2025年

作者： Huang, Yuting Toedtli, Simon S. Chini, Gregory P. McKeon, Beverley J. Mechanical and Civil Engineering California Institute of Technology PasadenaCA91125 United States National Center for Atmospheric Research BoulderCO80301 United States Program in Integrated Applied Mathematics Department of Mechanical Engineering University of New Hampshire DurhamNH03824 United States Department of Mechanical Engineering Center for Turbulence Research Stanford University StanfordCA94305 United States

The quadratic convection term in the incompressible Navier-Stokes equations is considered as a nonlinear forcing to the linear resolvent operator, and it is studied in the Fourier domain through the analysis of interactions between triadically compatible wavenumber-frequency triplets. A framework to quantify the triadic contributions to the forcing and response by each pair of triplets is developed and applied to data from direct numerical simulations of a turbulent channel at Reι ≈ 550. The linear resolvent operator is incorporated to provide the missing link from energy transfer between modes to the effect on the spectral turbulent kinetic energy. The coefficients highlight the importance of interactions involving large-scale structures, providing a natural connection to the modeling assumptions in quasi-linear (QL) and generalized quasi-linear (GQL) analyses. Specifically, it is revealed that the QL and GQL reductions efficiently capture important triadic interactions in the flow, especially when including of a small number of wavenumbers into the GQL large-scale base flow. Additionally, spatio-temporal analyses of the triadic contributions to a single mode representative of the near-wall cycle demonstrate the spatio-temporal nature of the triadic interactions and the effect of the resolvent operator, which selectively amplifies certain forcing profiles. The tools presented are expected to be useful for improving modeling of the nonlinearity, especially in QL, GQL, and resolvent analyses, and understanding the amplitude modulation mechanism relating large-scale fluctuations to the modulation of near-wall structures. © 2025, CC BY.

关键词： Navier Stokes equations

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