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2023 2nd International Conference on Materials Science and Engineering, CoMSE 2023

作者： Ba, Mingsen Qin, Wenjie Zhao, Zhenlong Sun, Yu Beijing Institute of Technology China State Key Laboratory of Engine and Powertrain System China

The accumulation of small tangential slip will occur on the contact surfaces of components in mechanical structures when subjected to cyclic loadings, which will lead to system failure. However, the small tangential slip is difficult to measure directly. In this paper, a method for measuring the contact slip by using a self-powered displacement sensor based on triboelectric nanogenerator (TENG) is proposed, and the accuracy is verified by the finite element analysis (FEA). The contact slips for a flat-on-flat contact configuration are measured by this method. When the test piece is subjected to a cyclic tangential load with a frequency of 10Hz, the average obtained slip displacement of the test piece under single load cycle is less than 10μm. Then the finite element simulation of the contact configuration is carried out using software Abaqus 6.14. The analysis results are close to the test results, which verifies the effectiveness of the measurement method. Moreover, the slips of the flat-on-flat contact configuration under different frequency and amplitude of cyclic tangential load are investigated. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Finite element method

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Design of A Rigid-soft Hybrid Robotic Glove with Force Sensing Function

Design of A Rigid-soft Hybrid Robotic Glove with Force Sensi...

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IEEE International Conference on robotics and Automation (ICRA)

作者： Hexin Li Li Jiang Ruichen Zhen Ming Cheng Kehan Ding State Key Laboratory of Robotics and System Harbin Institute of Technology

ISBN: (数字)9798350384574

ISBN: (纸本)9798350384581

Soft robotic gloves can not only provide timely, effective, safe and cheap rehabilitation training for patients with impaired movement function of hand, but also assist in completing daily grasping activities. However, most soft robotic gloves are completely composed of flexible structures. Although they have high flexibility and safety, there are problems such as poor fit and low output force. In order to solve these problems, this paper refers to the structure of the human hand and designs an articulated rigid-soft hybrid robotic glove, which combines the advantages of rigid robotic gloves and soft robotic gloves, and has high flexibility, high output force and good fit. In addition, soft robotic gloves generally lack the ability to sense the force between the human hand and the glove. Therefore, this paper designed an array flexible force sensor, and studied the structure, signal acquisition and preparation process of the sensor. Finally, a complete test platform was built to test the performance of the rigid-soft hybrid robotic glove with force sensing function. The test results show that the robotic glove has good fit and high output force, can effectively assist training and assist grasping, and can perceive the contact force.

关键词： Training Sensitivity Force Grasping Soft robotics Robot sensing systems Safety

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The hydrodynamics of self-rolling locomotion driven by the flexible pectoral fins of 3-D bionic dolphin

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Journal of Ocean Engineering and Science 2022年第1期7卷 29-40页

作者： Zhihan Li Dan Xia Xufeng Zhou Jiabo Cao Weishan Chen Xingsong Wang School of Mechanical Engineering Southeast UniversityNanjing 211189China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150080China

The novel autonomous rolling performance is realized by the pair of pectoral fins of a three-dimensional(3-D)bionic dolphin in this paper numerically.3-D Navier-Stokes equations are employed to simulate the viscous fluid around the bionic *** effect of self-rolling manoeuvrability is ex-plored using the dynamic mesh technology and user-defined function(UDF).By varying the parameter ratios,the interaction of flexible pectoral fins is divided into two motion modes,amplitude differential and frequency differential *** the primary driving source,the differential motion of a pair of pec-toral fins can effectively provide the rolling torque,and the trajectory of the entire rolling process is approximately the clockwise *** results demonstrate that the rolling angular velocity and driving torque in the steady state can be improved by increasing parameter ratios,and the rolling efficiency can reach the maximum under the optimal parameter ***,different parameter ratios do not af-fect the rolling radius of the self-rolling *** evolution process around the pair of pectoral fins is shown by the flow structures in self-rolling swimming,reasonably revealing that self-rolling locomotion is produced by the pressure and wake vortices surrounding the pair of pectoral fins,and the wake struc-tures depend primarily on the variation of parameter *** properly turns out that the application of the pair of pectoral fins can realize the self-rolling performance through parameter differential modes.

关键词： Self-rolling dolphin Parameter differential mode Numerical simulation Hydrodynamic performance Flow structures

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Experimental Study on Geometry Characteristics of Turbulent Premixed Flames for Natural Gas/Air Mixtures

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Journal of Thermal Science 2025年第1期34卷 268-282页

作者： ZHENG Weilin WANG Qijiao XIAO Huahua CHEN Xiaoxiao XIE Fan ZENG Wen Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace UniversityShenyang 110136China State Key Laboratory of Fire Science University of science and Technology of ChinaHefei 230027China AVIC Shenyang Aircraft Design and Research Institute Shenyang 110035China

In this study,focusing on the geometry characteristics of spherical expanding flame,the turbulent premixed flames of natural gas/air mixtures were investigated in a fan-stirred turbulent *** effects of initial temperature(T=300-400 K),initial pressure(P=0.1-0.3 MPa),turbulence intensity(u'=1.0-2.7 m/s),oxygen volumetric percentage(φ(O_(2))=15%-21%)and carbon dioxide volumetric percentage(φ(CO_(2))=0-20%)were delved *** flame profile under the Cartesian coordinate system was derived from the schlieren images taken by the high-speed ***,from both macroscopic and microscopic perspectives,the influence of experimental conditions on the flame geometry characteristics was explored through flame front extraction,wavelet decomposition and network *** results demonstrate that for significant flame wrinkling,changes in species concentrations and turbulence intensity have more pronounced effects on the flame wrinkling *** wrinkling of the flame front maintains a certain degree of similarity,as evidenced by the locally concentrated distribution of the angles of the maximum fluctuation *** disturbance energy under large-scale(D6-D8)disturbances exhibits relatively high values with a similar trend,exerting a significant impact on the geometry characteristics of the flame *** peaks of correlation degree are scattered either with the decomposition scale or the development of flame radius,indicating no linear correlation between different detail ***,the probability distribution of node degrees in key wrinkled regions exhibits different trends with that of large-scale wrinkling and disturbance energy,especially with changes in initial *** occurs because the number of key wrinkles varies based on the perturbation's strength or the region's ***,an increase in the fluctuation frequency of the flame's local radius may not necessarily lead to an increase in the number of key folded regions.

关键词： geometry characteristics large-scale wrinkling wavelet decomposition network topology fan-stirred turbulent combustor

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General closed-form inverse kinematics for arbitrary three-joint subproblems based on the product of exponential model

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Frontiers of Mechanical Engineering 2022年第2期17卷 85-101页

作者： Tao SONG Bo PAN Guojun NIU Jiawen YAN Yili FU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mechanical Engineering and Automation Zhejiang Sci-Tech UniversityHangzhou 310018China

The inverse kinematics problems of robots are usually decomposed into several Paden–Kahan subproblems based on the product of exponential model. However, the simple combination of subproblems cannot solve all the inverse kinematics problems, and there is no common approach to solve arbitrary three-joint subproblems in an arbitrary postural relationship. The novel algebraic geometric (NAG) methods that obtain the general closed-form inverse kinematics for all types of three-joint subproblems are presented in this paper. The geometric and algebraic constraints are used as the conditions precedent to solve the inverse kinematics of three-joint subproblems. The NAG methods can be applied in the inverse kinematics of three-joint subproblems in an arbitrary postural relationship. The inverse kinematics simulations of all three-joint subproblems are implemented, and simulation results indicating that the inverse solutions are consistent with the given joint angles validate the general closed-form inverse kinematics. Huaque III minimally invasive surgical robot is used as the experimental platform for the simulation, and a master–slave tracking experiment is conducted to verify the NAG methods. The simulation result shows the inverse solutions and six sets given joint angles are consistent. Additionally, the mean and maximum of the master–slave tracking experiment for the closed-form solution are 0.1486 and 0.4777 mm, respectively, while the mean and maximum of the master–slave tracking experiment for the compensation method are 0.3188 and 0.6394 mm, respectively. The experiments results demonstrate that the closed-form solution is superior to the compensation method. The results verify the proposed general closed-form inverse kinematics based on the NAG methods.

关键词： inverse kinematics Paden-Kahan subproblems three-joint subproblems product of exponential closed-form solution

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Versatile Jumping of Humanoid Robots via Curriculum-Assisted Reinforcement Learning

Versatile Jumping of Humanoid Robots via Curriculum-Assisted...

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2024 China Automation Congress, CAC 2024

作者： Tan, Ruiyu Li, Xueai Ni, Fenglei Zhou, Dong Ji, Yi Shao, Xiangyu Key Laboratory of Autonomous Intelligent Unmanned Systems Harbin Institute of Technology Harbin China State Key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin China

ISBN: (纸本)9798350368604

Versatile jumping is crucial for agile and adaptive behavior of humanoid robots in complex environments. However, humanoid robots have to manage impact forces while maintaining balance and stability throughout the take-off, flight, and landing phases, which imposes significant challenges for motion planning and controller design. This paper proposes a curriculum-assisted reinforcement learning framework for the humanoid robot to achieve various jumping tasks. The curriculum learning divides the jump training process into multi-stages and design different episodes in each stage to guarantee the training feasibility and generalize learned skills. Simulations on a 28 DOFs humanoid robot verify the excellent diverse jumping capability of the proposed policy. This exploration of different tasks also proves the policy’s robustness, allowing the robot quickly recover from perturbations using a variety of learned maneuvers. © 2024 IEEE.

关键词： Anthropomorphic robots

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Meter-Scale Thin-Walled Structure with Lattice Infill for Fuel Tank Supporting Component of Satellite:Multiscale Design and Experimental Verification

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Computer Modeling in Engineering & Sciences 2024年第1期138卷 201-220页

作者： Xiaoyu Zhang Huizhong Zeng Shaohui Zhang Yan Zhang Mi Xiao Liping Liu Hao Zhou Hongyou Chai Liang Gao Beijing Key Laboratory of Lightweight Multi-Functional Composite Materials and Structures Beijing Institute of TechnologyBeijing100081China Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System EngineeringChina Academy of Space TechnologyBeijing100094China Key Laboratory of Metallurgical Equipment and Control Technology Ministry of EducationWuhan University of Science and TechnologyWuhan430081China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan430074China

Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting fromthe sandwich *** structures can be fabricated bymetallic additive manufacturing technique,such as selective laser melting(SLM).However,the maximum dimensions of actual structures are usually in a sub-meter scale,which results in restrictions on their appliance in aerospace and other *** this work,a meter-scale thin-walled structure with lattice infill is designed for the fuel tank supporting component of the satellite by integrating a self-supporting lattice into the thickness optimization of the *** designed structure is fabricated by SLM of AlSi10Mg and cold metal transfer welding ***-static mechanical tests and vibration tests are both conducted to verify the mechanical strength of the designed large-scale lattice thin-walled *** experimental results indicate that themeter-scale thin-walled structure with lattice infill could meet the dimension and lightweight requirements of most spacecrafts.

关键词： Thin-walled structure lattice infill supporting component selective laser melting satellite

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Robustness and Push Recovery of Humanoid Robots Using Predictive and Whole-Body Control

Robustness and Push Recovery of Humanoid Robots Using Predic...

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2024 IEEE International Conference on Unmanned systems, ICUS 2024

作者： Zhang, Shaojie Ni, Fenglei Li, Xueai Li, Xu Ji, Yi Shao, Xiangyu State Key Laboratory of Robotics and Systems Harbin Institute of Technology Harbin China Key Laboratory of Autonomous Intelligent Unmanned Systems Harbin Institute of Technology Harbin China

ISBN: (纸本)9798350384185

Robustness walking and recovery ability in uneven terrains and unexpected collisions are crucial for the practical application of humanoid ***, existing methods struggle to effectively balance stability, motion safety and walking *** paper proposes a hybrid control strategy combing Nonlinear Model Predictive Control (NMPC) and Whole-Body Control (WBC) to improve the robot's walking stability and reaction safety in collisions *** NMPC generates long-term and macroscopic movements, with capture point theory being utilized for foot placements determination under external *** this foundation, the WBC regulates the robot refinedly in real-time based on task priorities and *** verify the effectiveness of the proposed method, involving uneven terrain walking and external impacts rejection. © 2024 IEEE.

关键词： Anthropomorphic robots

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Hierarchical Trajectory Optimization for Humanoid Robot Jumping Motion 16th

Hierarchical Trajectory Optimization for Humanoid Robot Jump...

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16th International Conference on Intelligent robotics and Applications, ICIRA 2023

作者： Sun, Junbao Liu, Haopeng Li, Xu Feng, Haibo Fu, Yili Zhang, Songyuan Intelligent Robot Research Center Zhejiang Laboratory Hangzhou311100 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

ISBN: (纸本)9789819964796

In order to make the robot have high dynamic motion ability, this paper uses the trajectory optimization method to plan the jumping motion trajectory of the humanoid robot quickly and effectively, and carries out the jumping motion experiment on the HIT-HU humanoid robot platform. In order to improve the solving speed of trajectory optimization problem, simplified centroid dynamics model and single rigid body model are established. Differential dynamic programming (DDP) based on the combination of the centroid dynamic model and the whole body joint kinematic model is used to solve the hopping trajectory optimization problem with high accuracy, and the external penalty function method is used to deal with the relevant constraints. In order to overcome the problem that the solver is sensitive to the initial point selection, a hierarchical trajectory optimization framework is proposed. The framework uses the direct collocation method based on the single rigid body model. The trajectory of the simplified model is used as the initial trajectory guess, and the differential dynamic programming method is introduced to solve the optimal trajectory of the whole joint. The differential dynamic programming algorithm using the direct method of warm start is about twice as fast as the method of manually given initial trajectory. The simulation and experimental verification of the vertical jump trajectories generated by the algorithm on the humanoid robot HIT-HU show that the jump trajectories generated by the algorithm can be effectively transformed into the motion trajectories of humanoid robots, and can be effectively executed on the physical prototype. This further verifies the effectiveness of the algorithm and plays an important role in practical application. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.

关键词： Anthropomorphic robots

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Hybrid ROCOV/Waveform Similarity Coefficient Based Protection for DC Lines in HVDC Grids

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CSEE Journal of Power and Energy systems 2024年第6期10卷 2423-2433页

作者： Wenxia Sima Zhengzheng Fu Ming Yang Tao Yuan Pan Duan Potao Sun State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing 400044China School of Automation Chongqing University of Posts and TelecommunicationsChongqing 400065China

DC line protection with high speed and strong robustness against high fault resistance is essential in highvoltage direct current(HVDC)*** conventional voltagederivative-based protections for DC lines exhibit the problem of low reliability on the occurrence of high-impedance *** this paper,fault traveling waves at the fault point and at the line side of the DC reactor are first analyzed using phasemodal *** on the theoretical analysis of the modal fault-component voltages at the line side of the DC reactor,a novel hybrid protection scheme utilizing the single-ended rate of change of voltage(ROCOV)and waveform similarity coefficient is *** utilizes the hybrid ROCOV criterion and waveform similarity coefficient to identify the faulted line and the amplitudes of the 0-and 1-mode fault-component voltages to identify fault type,and the polarities of the 0-and 1-mode fault-component voltages to identify faulted *** under various fault conditions verify that the proposed protection scheme can achieve fast and reliable identification of faulted line,fault type,and faulted pole in 1 ms,and effectively improve the reliability against high-impedance faults up to 1200.

关键词： DC line protection MMC-HVDC grid phasemodal transformation ROCOV waveform similarity coefficient

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