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14th International Munich Chassis Symposium, IMCS 2023

作者： Gonschorek, Robert Bertram, Torsten ZF Automotive Germany GmbH Düsseldorf Germany Institute of Control Theory and Systems Engineering TU Dortmund Dortmund Germany

ISBN: (纸本)9783662703472

Upcoming vehicle generations will provide fault-tolerant onboard power supply systems and an increasing level of driving automation. These changes contribute to the applicability of Steer-by-Wire (SbW) systems and the development of automated lateral vehicle guidance control functions. For the market acceptance of automated driving the lateral vehicle guidance control function must be cooperative, that implies it must permit driver interventions. This contribution proposes a cooperative control concept for the Handwheel Actuator (HWA) of a SbW system, which enables a true coexistence between steering position and steering torque control. The controller performs precise tracking of the reference steering position provided by a lateral vehicle guidance controller. In the event of a driver intervention, the driver can override the active control and experiences a natural steering feel. In contrast to existing approaches, the transitions hereby are seamless as no gain scheduling, switching or controller output saturation are required. Moreover, a consistent control performance is ensured. After the derivation of a mathematical system model, identification, and model evaluation, the cooperative control concept is systematically designed. Besides a frequency domain analysis of the nominal control performance and stability, real vehicle tests are conducted to verify simulation results and get a representative view of the controller performance. © The Author(s), under exclusive license to Springer-Verlag GmbH, DE, part of Springer Nature 2025.

关键词： Frequency domain analysis

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Next-Best-Trajectory Planning of Robot Manipulators for Effective Observation and Exploration

arXiv

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arXiv 2025年

作者： Renz, Heiko Krämer, Maximilian Hoffmann, Frank Bertram, Torsten Institute of Control Theory and Systems Engineering TU Dortmund University Dortmund Germany

Visual observation of objects is essential for many robotic applications, such as object reconstruction and manipulation, navigation, and scene understanding. Machine learning algorithms constitute the state-of-the-art in many fields but require vast data sets, which are costly and time-intensive to collect. Automated strategies for observation and exploration are crucial to enhance the efficiency of data gathering. Therefore, a novel strategy utilizing the Next-Best-Trajectory principle is developed for a robot manipulator operating in dynamic environments. Local trajectories are generated to maximize the information gained from observations along the path while avoiding collisions. We employ a voxel map for environment modeling and utilize raycasting from perspectives around a point of interest to estimate the information gain. A global ergodic trajectory planner provides an optional reference trajectory to the local planner, improving exploration and helping to avoid local minima. To enhance computational efficiency, raycasting for estimating the information gain in the environment is executed in parallel on the graphics processing unit. Benchmark results confirm the efficiency of the parallelization, while real-world experiments demonstrate the strategy’s effectiveness. Copyright © 2025, The Authors. All rights reserved.

关键词： Robot applications

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Mechanical Properties Inside Origami-Inspired Structures: An Overview

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Applied Mechanics Reviews 2025年第1期77卷 011001页

作者： Yan, Peng Huang, Hailin Meloni, Marco Li, Bing Cai, Jianguo Department of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen518052 China Harbin Institute of Technology Shenzhen518052 China Key Laboratory of C & PC Structures of Ministry of Education National Prestress Engineering Research Center Southeast University Nanjing211189 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology Shenzhen518052 China Key University Laboratory of Mechanism Machine Theory and Intelligent Unmanned Systems of Guangdong Habin Institute of Technology Shenzhen518052 China

In recent decades, origami has transitioned from a traditional art form into a systematic field of scientific inquiry, characterized by attributes such as high foldability, lightweight frameworks, diverse deformation modes, and limited degrees-of-freedom. Despite the abundant literature on smart materials, actuation methods, design principles, and manufacturing techniques, comprehensive reviews focusing on the mechanical properties of origami-inspired structures are relatively rare and unsystematic. This review aims to fill this void by analyzing and summarizing the significant studies conducted on the mechanical properties of origami-inspired structures from 2013 to 2023. We begin with an overview that includes essential definitions of origami, classical origami patterns, and their associated tessellated or stacked structures. Following this, we delve into the principal dynamic modeling method for origami and conduct an in-depth analysis of the key mechanical properties of origami-inspired structures. These properties include tunable stiffness, bistability and multistability, metamechanical properties demonstrated by origami-based metamaterials, and bio-inspired mechanical properties. Finally, we conclude with a comprehensive summary that discusses the current challenges and future directions in the field of origami-inspired structures. Our review provides a thorough synthesis of both the mechanical properties and practical applications of origami-inspired structures, aiming to serve as a reference and stimulate further research. © 2025 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Degrees of freedom (mechanics)

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Design and Analysis of a Compact and Foldable Master Device Based on Binocular Near-Infrared Optical Navigation Technology for Minimally Invasive Surgery Robots

IEEE Transactions on Medical Robotics and Bionics

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IEEE Transactions on Medical Robotics and Bionics 2025年第2期7卷 514-527页

作者： Pan, Lizhi Jiang, Xu Ma, Zhikang Guan, Bo Yi, Bo Zhao, Jianchang Tianjin University School of Mechanical Engineering key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin300350 China Tianjin University Institute of Medical Robotics and Intelligent Systems Tianjin300072 China Surgeon Branch of Hunan Medical Doctor Association Disease Professional Committee of Chinese Medical Doctor Association Third Xiangya Hospital of Central South University China Hunan Provincial Key Laboratory of Surgical Robotics Hunan China Tsinghua University School of Aeronautics and Astronautics Beijing100084 China

The traditional minimally invasive surgical (MIS) robots generally have bulk master manipulators with relatively fixed working positions, which limits their further utilization in special scenarios, such as remote surgeries. This study proposes a compact and foldable master device based on passive binocular near-infrared (NIR) optical navigation technology for MIS robots, which does not need mechanical arm linkage constraints and provides a larger range of position and orientation tracking, enabling the surgeons to perform continuous master-slave manipulations more steadily. Moreover, the polyhedral and foldable structure of the optical master device further reduces the spatial footprint of the MIS robot. A prototype of the optical master devices was constructed with a weight of 186 g. Its performance was then evaluated through testing, and the maximum average absolute error in position and orientation tracking was 0.90 mm and 0.45°, respectively. Additionally, the prototype exhibits acceptable stability and a wide range of position and orientation tracking. The master device features a compact, foldable structure with enhanced portability and excellent position and orientation tracking capabilities, facilitating precise surgical maneuvers of surgeons in scenarios of remote surgeries. © 2018 IEEE.

关键词： Knee prostheses

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Enhanced corrosion resistance of laser powder bed fusion 316L stainless steel by modifying the microstructure through heat treatment

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Journal of Materials Research and Technology 2025年 36卷 7158-7171页

作者： Cuiling Zhao Yuchao Bai Qi Yan Bing Li Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robots Harbin Institute of Technology Shenzhen 518055 China Key University Laboratory of Mechanism & Machine Theory and Intelligent Unmanned Systems of Guangdong Harbin Institute of Technology Shenzhen 518055 China School of Robotics and Advanced Manufacture Harbin Institute of Technology Shenzhen 518055 China Department of Mechanical Engineering College of Design and Engineering National University of Singapore Singapore 117575 Singapore

This study aims to investigate the microstructural evolution of laser powder bed fusion (LPBF) 316L stainless steel during heat treatment and its effect on corrosion resistance through microstructural characterization and corrosion testing. The results show that the as-built LPBF samples featured melt pool boundaries, cellular structures, a few nano-sized manganese silicate particles and irregular grains with strong fiber texture <101>, which are retained after heat treatment at 450 °C. With temperature increase to 850 °C, a σ phase rich in Cr, Mo, and S elements was formed. Subsequently, after heat treatment at 1100 °C, melt boundary disappears and large square grains similar to the cast counterparts appear. Electrochemical tests demonstrate that the corrosion resistance of LPBF samples surpasses the cast samples heat treated at 1100 °C. In addition, annealing at or below 1100 °C will reduce the corrosion resistance of LPBF samples due to the formation of hazardous precipitates. However, after heat treatment at 1300 °C, the best corrosion resistance was obtained due to the diffusion of Cr, Mo and S elements into the matrix and homogeneous microstructure. This study provides a method for effectively improving the corrosion resistance of LPBF 316L stainless steel and understanding the corresponding corrosion mechanism.

关键词： Laser powder bed fusion Corrosion behaviour Heat treatment 316L stainless steel Microstructure

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A Tensor Low-Rank Approximation for Value Functions in Multi-Task Reinforcement Learning

arXiv

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arXiv 2025年

作者： Rozada, Sergio Paternain, Santiago Bazerque, Juan Andrés Marques, Antonio G. Dept. of Signal Theory and Communications King Juan Carlos University Madrid Spain Dept. of Electrical Computer and Systems Engineering Rensselaer Polytechnic Institute TroyNY United States Dept. of Electrical and Computer Engineering University of Pittsburgh PittsburghPA United States

In pursuit of reinforcement learning systems that could train in physical environments, we investigate multi-task approaches as a means to alleviate the need for massive data acquisition. In a tabular scenario where the Q-functions are collected across tasks, we model our learning problem as optimizing a higher order tensor structure. Recognizing that close-related tasks may require similar actions, our proposed method imposes a low-rank condition on this aggregated Q-tensor. The rationale behind this approach to multi-task learning is that the low-rank structure enforces the notion of similarity, without the need to explicitly prescribe which tasks are similar, but inferring this information from a reduced amount of data simultaneously with the stochastic optimization of the Q-tensor. The efficiency of our low-rank tensor approach to multi-task learning is demonstrated in two numerical experiments, first in a benchmark environment formed by a collection of inverted pendulums, and then into a practical scenario involving multiple wireless communication devices. Copyright © 2025, The Authors. All rights reserved.

关键词： Multi-task learning

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Design and Validation of a Novel Human-Machine Interface System Based on Multi-Source Data Fusion

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IEEE Transactions on Instrumentation and Measurement 2025年 74卷

作者： Pan, Lizhi Wang, Chaofan Li, Zihao Zhao, Jianchang Zhang, Chi Li, Jianmin Tianjin University Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education School of Mechanical Engineering Tianjin300350 China Tianjin University Institute of Medical Robotics and Intelligent Systems Tianjin300350 China Tsinghua University National Engineering Research Center of Neuromodulation School of Aerospace Engineering Beijing100084 China

Conventional human-machine interface (HMI) systems generally take surface electromyography as the only signal source, which often faces the problem of multi-channel crosstalk. To enhance HMI performance, this study introduces a novel three-degree-of-freedom HMI system for surgical robot control, which integrates surface electromyography signals and inertial measurement unit signals. A cost-effective wearable HMI hardware system is designed to address the high price and poor portability of existing commercial equipment, which also has a higher signal-to-noise ratio of 35.9 dB. Based on the proposed simultaneous and proportional control strategy, ten subjects were recruited to conduct an online experiment involving four upper limb postures to assess the real-time performance of the HMI system. Additionally, six able-bodied participants participated in a validation experiment to statistically verify and rigorously evaluate the implemented HMI system. The experimental results demonstrate that our HMI system can accurately decode the angles of the wrist and metacarpophalangeal joints in both single-degree-of-freedom and three-degree-of-freedom movements, achieving stable control and robust online performance. Furthermore, the proposed HMI system was applied to a flexible endoscopic robot to realize remote simultaneous and proportional control, and the results indicate that it can perform well in the practical application. The current study proves the feasibility and practicability of multi-source data fusion for HMI, providing a new direction. © 1963-2012 IEEE.

关键词： Surgical equipment

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Polymer dynamics under tension: Mean first passage time for looping

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Physical Review E 2025年第2期111卷 025401-025401页

作者： Wout Laeremans Anne Floor den Ouden Jef Hooyberghs Wouter G. Ellenbroek Soft Matter and Biological Physics Department of Applied Physics and Science Education and Institute for Complex Molecular Systems Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven Netherlands Laboratory of Physical Chemistry Department of Chemical Engineering and Chemistry Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven Netherlands UHasselt Faculty of Sciences Data Science Institute Theory Lab Agoralaan 3590 Diepenbeek Belgium

This study deals with polymer looping, an important process in many chemical and biological systems. We investigate basic questions on the looping dynamics of a polymer under tension using the freely jointed chain (FJC) model. Previous theoretical approaches to polymer looping under tension have relied on barrier escape methods, which assume local equilibrium, an assumption that may not always hold. As a starting point, we use an analytical expression for the equilibrium looping probability as a function of the number of monomers and applied force, predicting an inverse relationship between looping time and looping probability. Using molecular dynamics simulations, the predictions of this theoretical approach are validated within the numerical precision achieved. We compare our predictions to those of the barrier escape approach by way of a calculation of the mean first passage time (MFPT) for the ends of a polymer to cross. For this purpose, we derive the exact free energy landscape, but the resulting temporal predictions do not agree with the observed inverse scaling. We conclude that the traditional barrier escape approach does not provide satisfactory predictions for polymer looping dynamics and that the inverse scaling with looping probability offers a more reliable alternative.

关键词： Inverse problems

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Photon-assisted stochastic resonance in nanojunctions

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Physical Review B 2025年第9期111卷 094309-094309页

作者： Michael Ridley Leo Bellassai Michael Moskalets Lev Kantorovich Riku Tuovinen Faculty of Engineering and Institute of Nanotechnology and Advanced Materials Bar Ilan University Ramat Gan 52900 Israel Department of Physics Nanoscience Center P.O. Box 35 40014 University of Jyväskylä Finland Institute for Cross-Disciplinary Physics and Complex Systems (IFISC) (UIB-CSIC) 07122 Palma de Mallorca Spain Department of Metal and Semiconductor Physics NTU “Kharkiv Polytechnic Institute” 61002 Kharkiv Ukraine Theory and Simulation of Condensed Matter (TSCM) King's College London Strand London WC2R 2LS United Kingdom

We study stochastic resonance in molecular junctions driven by a periodically varying external field. This is done using the time-dependent Landauer-Büttiker formalism, which follows from exact analytical solutions to the Kadanoff-Baym equations describing the molecular junction subject to an arbitrary time-dependent bias. We focus on a double quantum dot nanojunction and compare the effects of the temperature with the fluctuating bias in the statically driven case. We then consider the combined effect of AC driving and white-noise fluctuations on the rectified current through the nanojunction, and find a stochastic resonance effect, where at certain driving conditions the bias fluctuations enhance the current signal. The study is then extended to include the color noise in the applied bias, so that the combined effect of the color noise correlation time and driving frequency on stochastic resonance is investigated. We thereby demonstrate that photon-assisted transport can be optimized by a suitably tuned environment.

关键词： White noise

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Overcoming the Passivity Bounds in Communications systems with Spacetime Modulations

Overcoming the Passivity Bounds in Communications Systems wi...

引用

European Conference on Antennas and Propagation, EuCAP

作者： Salvador Moreno-Rodríauez Antonio Alex-Amor Mario Pérez-Escribano Juan F. Valenzuela-Valdés Pablo Padilla Carlos Molero Department of Signal Theory Telematics and Communications Research Centre for Information and Communication Technologies (CITIC-UGR) University of Granada Granada Spain Department of Electrical and Systems Engineering University of Pennsylvania Philadelphia Pennsylvania United States Telecommunication Research Institute (TELMA) Universidad de Malaga E.T.S. Ingeniería de Telecomunicación Málaga Spain

ISBN: (数字)9788831299107

ISBN: (纸本)9798350366327

In this paper, we exploit the extra degrees of freedom associated with including time as a design variable to create communication scenarios beyond the physical bounds of passive structures. We particularize the results to a time-modulated diffractive one-dimensional grating. By tuning the temporal modulation, we show that two different scenarios can lead to the same output angles but with different output frequencies or incidence angles. These results illustrate the potential of these metastructures as diffractive beamformers and frequency mixers.

关键词： Wireless communication Time-frequency analysis Frequency modulation Europe Diffraction gratings Metamaterials Gratings Electromagnetics Tuning Mixers

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