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International Conference on Mechanical Design, ICMD 2023

作者： Zhai, Guangqing Xiao, Hong Yang, Guang Guo, Hongwei Tao, Jianguo Liu, Rongqiang State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China

ISBN: (纸本)9789819709212

Firstly, based on Absolute Nodal Coordinate Formulation (ANCF), the generalized coordinates, generalized stiffness, and generalized mass matrices of the rigid and flexible components in the multi-output deployment mechanism are established. Considering the inconsistency in the dimensions of the system’s generalized coordinate matrix and the generalized coordinate matrix of each single-output deployment mechanism, a coordinate coordination matrix is introduced. Composing the rigid-flexible coupling dynamics model of the multi-output transient deployment mechanism in the global coordinate system using each single-output deployment mechanism. The dynamic model is solved using the Newmark and BFD quasi-Newton methods, incorporating the system constraint equation matrix based on the Lagrange multiplier method. The calculated results are compared with the ABAQUS-ADAMS unified simulation. The two dynamic response change trends are basically consistent, with slight differences in oscillation amplitude, but similar overall, which verifies the accuracy of the constructed dynamic model. Compared to the rotational speed and acceleration of various outputs of the ideal rigid body simulation, the rigid-flexible coupling mechanism produces continuous oscillations above and below the output curve of the ideal rigid body. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

关键词： Dynamic models

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Channel Attention Network for Feature Fusion of Ultrasonic and IMU Signals in Cross-Subject Gait Recognition

Channel Attention Network for Feature Fusion of Ultrasonic a...

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2024 IEEE International Conference on systems, Man, and Cybernetics, SMC 2024

作者： Huang, Xujia Zhou, Zixiang Xu, Xinglong Wang, Zhiyong Harbin Institute of Technology State Key Laboratory of Robotics and System Shenzhen Shenzhen China

ISBN: (纸本)9781665410205

In traditional human-machine interface research, a single sensing mode is often adopted, focusing on individual human motion classification experiments. However, the performance often declines when applied across individuals. Ultrasonic and inertial sensing, as mainstream technologies in human-machine interfaces, can respectively detect the muscle states and limb information of the human body, offering potential complementary benefits. The fusion of ultrasonic(US) and Inertial Measurement Unit(IMU) is expected to significantly enhance the generalization ability of physiological signals in motion intention recognition. This paper presents a method that employs fusion of ultrasound and IMU signals, and designs a Convolutional Neural Network with Channel Attention Module (IU-CAM-CNN) for gait classification experiments. The experimental results demonstrate that by introducing channel attention modules, the model's ability to extract features from fused signals can be effectively enhanced, resulting in a classification accuracy of 90% for cross-individual movements. In contrast, traditional LDA and CNN networks achieve only 22% and 47% classification accuracy, respectively. This method provides an effective solution for cross-individual movement intention recognition. © 2024 IEEE.

关键词： Convolutional neural networks

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Analytical modeling of piezoelectric meta-beams with unidirectional circuit for broadband vibration attenuation

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1665-1684页

作者： Jiawei MAO Hao GAO Junzhe ZHU Penglin GAO Yegao QU State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

Broadband vibration attenuation is a challenging task in engineering since it is difficult to achieve low-frequency and broadband vibration control *** solve this problem,this paper designs a piezoelectric meta-beam with unidirectional electric circuits,exhibiting promising broadband attenuation *** analytical model in a closed form for achieving the solution of unidirectional vibration transmission of the designed meta-beam is developed based on the state-space transfer function *** method can analyze the forward and backward vibration transmission of the piezoelectric meta-beam in a unified manner,providing reliable dynamics solutions of the *** analytical results indicate that the meta-beam effectively reduces the unidirectional vibration across a broad low-frequency range,which is also verified by the solutions obtained from finite element *** designed meta-beam and the proposed analytical method facilitate a comprehensive investigation into the distinctive unidirectional transmission behavior and superb broadband vibration attenuation performance.

关键词： broadband vibration attenuation efficient closed-form analytical solution electromechanical coupling piezoelectric material vibration control

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Automatic Control of Magnetic Helical Microrobots Docking with Target Objects in Liquid Environments

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Journal of Bionic Engineering 2025年第2期22卷 574-584页

作者： Fu Zhao Haoran Rong Lefeng Wang State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin150080China Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin150080China

Bio-inspired magnetic helical microrobots have great potential for biomedical and micromanipulation applications. Precise interaction with objects in liquid environments is an important prerequisite and challenge for helical microrobots to perform various tasks. In this study, an automatic control method is proposed to realize the axial docking of helical microrobots with arbitrarily placed cylindrical objects in liquid environments. The docking process is divided into ascent, approach, alignment, and insertion stages. First, a 3D docking path is planned according to the positions and orientations of the microrobot and the target object. Second, a steering-based 3D path-following controller guides the helical microrobot to rise away from the container bottom and approach the target along the path. Third, based on path design with gravity compensation and steering output limits, alignment of position and orientation can be accomplished simultaneously. Finally, the helical microrobot completes the docking under the rotating magnetic field along the target orientation. Experiments verified the automatic docking of the helical microrobot with static targets, including connecting with micro-shafts and inserting into micro-tubes. The object grasping of a reconfigurable helical microrobot aided by 3D automatic docking was also demonstrated. This method enables precise docking of helical microrobots with objects, which might be used for capture and sampling, in vivo navigation control, and functional assembly of microrobots.

关键词： Magnetic actuation Helical microrobots Visual servo Motion control Docking

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Reinforcement Learning Navigation for Robots Based on Hippocampus Episode Cognition

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Journal of Bionic Engineering 2024年第1期21卷 288-302页

作者： Jinsheng Yuan Wei Guo Zhiyuan Hou Fusheng Zha Mantian Li Pengfei Wang Lining Sun State Key Laboratory of Robotics and System Harbin Institute of Technology(HIT)Harbin 150001China Shenzhen Academy of Aerospace Technology Shenzhen 518057China School of Mechanical and Electrical Engineering Lanzhou University of TechnologyLanzhou 730050China

Artificial intelligence is currently achieving impressive success in all ***,autonomous navigation remains a major challenge for *** learning is used for target navigation to simulate the interaction between the brain and the environment at the behavioral level,but the Artificial Neural Network trained by reinforcement learning cannot match the autonomous mobility of humans and *** hippocampus–striatum circuits are considered as key circuits for target navigation planning and *** paper aims to construct a bionic navigation model of reinforcement learning corresponding to the nervous system to improve the autonomous navigation performance of the *** ventral striatum is considered to be the behavioral evaluation region,and the hippocampal–striatum circuit constitutes the position–reward *** this paper,a set of episode cognition and reinforcement learning system simulating the mechanism of hippocampus and ventral striatum is constructed,which is used to provide target guidance for the robot to perform autonomous *** with traditional methods,this system reflects the high efficiency of learning and better Environmental *** research is an exploration of the intersection and fusion of artificial intelligence and neuroscience,which is conducive to the development of artificial intelligence and the understanding of the nervous system.

关键词： Episode cognition Reinforcement learning Hippocampus Robot navigation

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Photodetector array for measuring the spatial-temporal distribution characteristics of electric field in oil-pressboard insulation based on the Kerr electro-optic effect

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High Voltage 2025年第1期10卷 95-105页

作者： Chunjia Gao Bo Qi Chengrong Li Yukung Zheng State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina

Accurate measurement and effective analysis of the space electric field and charge characteristics within the oil-pressboard insulation structure of converter transformer are essential for achieving precise insulation structure ***,most electric field measurement methods relying on the Kerr electro-optical effect are limited to single-point *** the complexity of converter transformer insulation struc-tures,including their large scale and the use of various materials,existing technologies and findings struggle to provide comprehensive electric field observations within the oil-pressboard *** leveraging the Kerr electro-optic effect,a high-precision 32-unit photodetector array has been developed to achieve regional measurements of spatial-temporal electric field in oil-pressboard *** array boasts a measure-ment spatial resolution of 1.4 mm^(2)and a sensitivity of 0.15 kV/mm,ensuring mea-surement accuracy exceeding 96.50%.Through practical measurements of the spatial electric field distribution within the oil-pressboard insulation under direct current voltage,the non-uniform distribution of the electric field is effectively captured in ***,the maximum deviation in field strength at different positions within the transformer oil can reach 18.5%.Moreover,as the applied voltage increases,the un-evenness coefficient of the field strength gradually rises,peaking at 1.19,which signifies a progressive expansion in the area affected by electric field *** conducting tests to assess the dispersion of volume resistivity in samples from various positions within large sheets of pressboard,the variation in volume resistivity of materials is posited as one of the contributing factors to the non-uniform distribution of electric field within the *** detailed accomplishments aim to provide essential technical and theoretical support for optimising insulation structure design of converter transformers.

关键词： insulation distribution field

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Parallel multi-rate simulation scheme for modular multilevel converter-based high-voltage direct current with accurate simulation of high-frequency characteristics and field programmable gate array-based implementation

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High Voltage 2025年第1期10卷 17-31页

作者： Chongru Liu Yanqi Hou Haoyun Dong Yipeng Lv Xinyan Wang Chenbo Su State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina

The real-time simulation of the modular multilevel converter-based high-voltage direct current(MMC-HVDC)transmission system has become a popular research ***,in order to meet the real-time performance,the real-time simulation tech-nology will cause additional simulation errors for MMC-HVDC,especially on its fre-quency ***,a parallel multi-rate simulation scheme for MMC-HVDC is developed in this work to ensure accurate simulation of high-frequency ***,a non-error method based on converter transformer decoupling is proposed to decouple the converter and alternating current system;direct current transmission line decoupling and arm decoupling methods are used to achieve decoupling among and within converters.A multi-rate data synchronous mechanism is established by considering the differences among high-frequency characteristics caused by delayed data ***,the computing architectures of the primary system solver and modular multilevel converter controller are designed based on a field programmable gate array(FPGA).The real-time simulation platform for a four-terminal true bipolar MMC-HVDC is constructed based on the FPGA ***,the factors in multi-rate simulation affecting the simulation accuracy of high-frequency characteristics are *** simulator is shown to be accurate in steady and dynamic *** authors also verify its applicability for further research on high-frequency resonance based on control experiments.

关键词： interaction characteristics scheme

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Remaining Useful Life for Heavy-Duty Railway Cast Steel Knuckles Based on Crack Growth Behavior with Hypothetical Distributions

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Chinese Journal of Mechanical Engineering 2024年第4期37卷 290-305页

作者： Chao Wang Tao Zhu Bing Yang Shoune Xiao Guangwu Yang State Key Laboratory of Rail Transit Vehicle System Southwest Jiao tong UniversityChengdu 610031China

The current research on the integrity of critical structures of rail vehicles mainly focuses on the design stage,which needs an effective method for assessing the service *** paper proposes a framework for predicting the remaining useful life(RUL)of in-service structures with and without visible *** hypothetical distribution and delay time models were used to apply the equivalent crack growth life data of heavy-duty railway cast steel knuckles,which revealed the evolution characteristics of the crack length and life scores of the knuckle under different fracture failure *** results indicate that the method effectively predicts the RUL of service knuckles in different failure modes based on the cumulative failure probability curves for different locations and surface crack *** study proposes an RUL prediction framework that supports the dynamic overhaul and state maintenance of knuckle fatigue cracks.

关键词： Heavy-duty railway Cast steel knuckle Remaining useful life Fatigue crack growth Hypothetical distribution

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Design of a linear-rotary ultrasonic motor for optical focusing inspired by the bionic motion principles of the earthworms

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International Journal of Smart and Nano Materials 2022年第2期13卷 346-365页

作者： Yingzhi Wang Jie Deng Shijing Zhang He Li Weishan Chen Yingxiang Liu State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbinHeilongjiang ProvinceChina

Multi-motor configuration of multi-DOF(degree of freedom)optical system is a major source of redundant structure,putting a limitation on the simple and miniaturized ***,a novel two-DOF ultrasonic motor(USM)is proposed to provide a feasible method of application in the lens autofocus of the optical *** proposed USM operates by one longitudinal mode and two orthogonal bending modes,which is inspired by the bionic motion principle of the *** frequency degeneration among the three working modes is per-formed,and the working principle of the USM is verified via the FEM simulation.A prototype of the two-DOF USM is fabricated,and its mechanical output characteristics are *** experimental results indicate that the prototype achieves the maximum rotary and linear speeds of 3319.6 rpm and 57.6 mm/s,***,we demonstrate the result of a simple focusing experiment using the prototype and obtain a series of clear pictures,which verifies the feasibility of application in the optical focusing system.

关键词： Ultrasonic motor bondedtype two-DOF motions optical focusing bionic motion

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Investigation on laser annealing mechanism of fused silica optics polished by CO2 lasers based on fictive temperature distribution 8

Investigation on laser annealing mechanism of fused silica o...

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Advanced Laser Processing and Manufacturing VIII 2024

作者： Zhang, Tianhao Zhao, Linjie Chen, Mingjun Cheng, Jian Yin, Zhaoyang Li, Tianyuan State Key Laboratory of Robotics and System Harbin Institute of Technology Heilongjiang Harbin150001 China

ISBN: (数字)9781510681972

ISBN: (纸本)9781510681965

CO2 laser polishing process can significantly improve the surface quality and the laser-induced damage threshold (LIDT) of fused silica optics. However, due to the thermal history of the laser polishing process, the increment of the fictive temperature inside the modification layer would cause densification and residual stress, which critically affect the surface accuracy and the service life of fused silica optics. In this work, a 3D multi-physical coupling model including temperature, fluid flow and fictive temperature was established. Based on the fictive temperature distribution of the fused silica polished by CO2 lasers, the mechanism of laser annealing on the modified layer was revealed. The annealing results of fused silica were defined as three states including incomplete annealing, perfect annealing and over annealing. Based on the simulation results, the fictive temperature inside the modified layer was completely reduced with no increment of modified layer depth under the perfect annealing state. Additionally, the residual stress and the fictive temperature after the laser annealing were characterized by the Raman spectrum. The fictive temperature was reduced by 16.8 % and the residual stress was effectively reduced. This work can provide theoretical and experimental guidance for the control of surface modification and residual stress of fused silica optics polished by CO2 lasers. © 2024 SPIE.

关键词： Fused silica

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