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Bioinspired frog adaptive-mass quasi-zero stiffness vibration isolator

International Journal of Mechanical Sciences 2025年 301卷

作者： Wentao Wu Tianci Jiang Guangdong Sui Xiaobiao Shan Chenghui Sun Xiyan Xie Chunyu Zhou State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin 150001 China Institute of Ultra-precision Optoelectronic Instrument Engineering Harbin Institute of Technology Harbin 150001 China

This study proposes and systematically investigates a bioinspired frog vibration isolator (BFVI) featuring quasi-zero stiffness (QZS) characteristics and adaptive load capacity, aiming to address the degradation in vibration isolation performance commonly observed in traditional isolators under varying load conditions. A composite electromagnetic structure integrating horizontal and vertical configurations is constructed. The electromagnetic force model is derived using the filament method, and the influence of key geometric parameters—including structural rod length, initial angle, magnet dimensions, and current intensity—on the quasi-zero stiffness behavior is thoroughly analyzed. A nonlinear dynamic differential equation is established based on the Lagrange approach, and the harmonic balance method (HBM) is employed to reveal the transmission rate shift induced by mass variation. The effectiveness of adaptive current control in mitigating this shift is theoretically demonstrated. Furthermore, an active controller based on the nonlinear backstepping method is designed. Simulation results confirm adaptive current regulation effectively compensates for equilibrium deviation and performance loss caused by load fluctuations. Static experiments validate the QZS characteristics of the BFVI while time-varying load experiments confirm the controller's regulation capabilities and system response. Transmission rates under both fixed and adaptive current conditions are compared. Results show the system provides strong active regulation and effective low-frequency isolation under varying loads. This work offers new insights and strategies for integrating intelligent active control with bioinspired vibration isolation in complex engineering scenarios.

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CVFormer: Learning Circum-View Representation and Consistency for Vision-Based Occupancy Prediction via Transformers

CVFormer: Learning Circum-View Representation and Consistenc...

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IEEE International Conference on robotics and Automation (ICRA)

作者： Zhengqi Bai Wenjun Shi Dongchen Zhu Hanlong Kang Guanghui Zhang Gang Ye Yang Xiao Lei Wang Xiaolin Zhang Bo Li Jiamao Li Bionic Vision System Laboratory State Key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China University of Chinese Academy of Sciences Beijing China Lotus Robotics Ltd. Hangzhou China ShanghaiTech University Shanghai China

ISBN: (数字)9798350384574

ISBN: (纸本)9798350384581

With the increasing demands for perception accuracy in autonomous driving, there is a growing focus on fine-grained 3D semantic occupancy prediction. Effectively representing detailed three-dimensional scenes has become a significant challenge in the development of this task. In this paper, we present a novel transformer-based framework named CVFormer, which leverages two-dimensional circum-views from the ego to excavate three-dimensional features of the surrounding environment. Circum-views provide a novel solution for effectively addressing the representation of dense and fine-grained scenes. Specifically, a multi-attention module CTMA is designed for fusing temporal features from circum-views to fully exploit the spatiotemporal correlations between frames and capture more comprehensive clues. Furthermore, a novel 2D projection constraint is established by observing objects from different perspective directions, and multiple 3D constraints based on object invariance and semantic consistency are also conducted for supervising the network, which enhances its performance of understanding the scene. Experimental results on nuScenes dataset demonstrate that the proposed CVFormer obviously outperforms existing methods for occupancy prediction.

关键词： Training Solid modeling Three-dimensional displays Correlation Semantics Transformers Robot sensing systems

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Mitigating the Strength-Ductility Inversion in Nano-B4c/Al Composites by Constructing Heterogeneous Structure

SSRN

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SSRN 2023年

作者： Han, Bingzhuo Jiang, Longtao Han, Huimin Zhang, Runwei Du, Shanqi Luo, Tian Gong, Deng Xue, Wei Chao, Zhenlong Chen, Guoqin School of Materials Science and Engineering Harbin Institute of Technology No 92 West Dazhi Street Harbin150001 China State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology No 92 West Dazhi Street Harbin China Aero-Engine Control System Institute Aero Engine Corporation of China Wuxi214063 China

Heterogeneous nano-B4C/Al composites with soft and hard zones (SZs and HZs) were fabricated through a new approach combining segmented ball milling with pressure infiltration. It indicated that with the increase of step Ⅰ ball milling time, the width of SZs reduced. The heterogeneous composite with an SZ width of ~2.71 μm (Hetero-2μm) exhibited a 161 % increase in elongation compared to the homogeneous composite, with almost no decrease in ultimate tensile strength. Due to the mechanical incompatibility between the SZs and HZs, geometrically necessary dislocations (GND) accumulated near the interface. However, the length of GND pile-ups was finite, resulting in the presence of non-interface-affacted zones (NIAZ), which was harmful to the strength. The high strength of Hetero-2μm was attributed to the reduction of NIAZ width. Furthermore, the uniform distribution of plastic strain and some external toughening mechanisms, such as crack proliferation and deflection, were believed to be the reason for the ductility enhancement. © 2023, The Authors. All rights reserved.

关键词： Ball milling

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SpringExo, a spring-based exoskeleton for providing knee assistance: Design, Characterization and Feasibility Study

SpringExo, a spring-based exoskeleton for providing knee ass...

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IEEE International Conference on robotics and Automation (ICRA)

作者： Dongbao Sui Biing-Chwen Chang Rand Hidayah Yanhe Zhu Sunil K. Agrawal State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China Columbia University New York NY USA

This paper presents the design and preliminary evaluation of a portable spring-based knee exoskeleton, the SpringExo, which is designed to provide assistance to the leg while minimizing interference with the natural leg movement. Traditional rigid exoskeletons are unable to accurately align with a user’s anatomical joints. In addition, the user’s natural motion pattern is likely to change due to the constraints of the rigid exoskeleton. Though some textile-based soft exosuits and cable-driven soft exoskeletons have been developed to achieve better alignment with human’s biological joints, forces applied by the cables have to be sustained by human skeleton and joints. SpringExo, in comparison, uses a coil spring which the user wears around the thigh and shank, and does not require alignment with the joints. The spring stores energy and provides minimal interference during elastic deformation. A key feature of the SpringExo is that the springs store energy during the flexion phase and release this energy to assist the knee extension in the extension phase. We conducted human subjects study to verify its biomechanical and physiological effects on the user during stair ascent. Results from a six-subject study showed that the device did not interfere with the natural joint angles and assisted knee extension during stair ascent. However, further redesign and optimization are needed on the actuation system to offset SpringExo’s drawback of hindering knee flexion.

关键词： Knee Legged locomotion Exoskeletons Thigh Interference Stairs Skeleton

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Design and Development of a Rapidly Deployable Low-Cost Tensegrity In-Pipe Robot

Design and Development of a Rapidly Deployable Low-Cost Tens...

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IEEE/RSJ International Conference on Intelligent Robots and systems (IROS)

作者： Yixiang Liu Xiaolin Dai Kai Guo Jiang Wu Rui Song Jie Zhao Yibin Li School of Control Science and Engineering Shandong University Jinan China State Key Laboratory of Mechanical Transmissions Chongqing University Chongqing China Zhejiang Key Laboratory of Intelligent Operation and Maintenance Robot Hangzhou Shenhao Technology Co. Ltd Hangzhou China Engineering Research Center of Intelligent Unmanned System of Ministry of Education School of Control Science and Engineering Shandong University Jinan China School of Mechanical Engineering Shandong University Jinan China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China

Existing in-pipe robots have insufficient adaptability when dealing with accidents in unfamiliar pipe environments. Developing a pipe robot that can be designed and manufactured quickly is one solution. The tensegrity structure is a self-stressing spatial structure formed by the interaction of rigid members and flexible cables, which has the advantages of simple structure, good flexibility, deformability, and impact resistance. Inspired by this structure, we design a novel worm-like tensegrity robot for different pipe environments, which can be manufactured rapidly at low cost. Firstly, a robotic module based on the tensegrity structure is designed inspired by the motion patterns of worm-like organisms. Then, the design process of the module is presented based on the mathematical analysis of the deformation. Finally, a prototype of the tensegrity robot is developed using simple and low-cost parts in less than an hour. To test the motion performance, load performance, and inspection capability of the tensegrity robot, we designed a series of experiments on horizontal pipes, vertical pipes, elbows, and steel pipes. Experimental results show that the worm-like tensegrity robot is simple in structure, easy to manufacture, low in cost, and good in performance.

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Bionic knee joint structure and motion analysis of a lower extremity exoskeleton 4

Bionic knee joint structure and motion analysis of a lower e...

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4th International Conference on robotics and Automation Sciences, ICRAS 2020

作者： Xiao, Yongfei Ji, Xiangjing Wu, Hao Zhai, Xinpeng Fu, Xiaochun Zhao, Jie Institute of Automation Qilu University of Technology Shandong Academic of Science Shandong Provincial Key Laboratory of Robot and Manufacturing Automation Technology Jinan China Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China

ISBN: (纸本)9781728198576

In order to solve the problem of poor human-machine compliance of wearable lower extremity exoskeleton robots, a modified lower extremity exoskeleton with a four-bar mechanism in the knee joint is proposed and analyzed. The advantages of the four-bar mechanism relative to the traditional two-bar hinge structure are explained by analyzing the physiological characteristics of the human knee joint. In addition, the kinematics of traditional and modified lower extremity exoskeletons are compared. The constraint relationship and motion equations of instantaneous rotating center of the four-bar linkage knee joint are derived. Finally, gait simulations are performed on the two lower extremity exoskeleton models to obtain the position and angle information of the joints. The influence of the four-bar mechanism of bionic knee joint on the lower extremity exoskeleton is described. The simulation results show that the modified lower extremity exoskeleton not only improves the biomimetic performance of knee joint, but also conforms to the characteristics of human gait. © 2020 IEEE.

关键词： Kinematics

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航空发动机机匣修复用AlSi10Mg激光金属沉积:显微硬度、磨损和腐蚀行为

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表面工程与再制造 2024年第2期24卷 53-53页

作者： Enjie Dong Tingyu Chang Linjie Zhao Yunhao Xing Jiaxuan Chen Mingjun Chen Junwen Lu Jian Cheng State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin Heilongjiang 150001 China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang University Hangzhou 310027 China Aircraft Repair & Overhaul Plant/Sichuan Province Engineering Technology Research Center of General Aircraft Maintenance Civil Aviation Flight University of China Guanghan 618307 China

基于激光金属沉积(Laser Metal Deposition,LMD)的再制造利用了增材制造的灵活性,为修复或再制造高价值工程零部件提供了一种极具吸引力和性价比的手段。本工作在航空发动机机匣用铸造铝合金板表面熔覆AlSi10Mg合金,当激光功率P=1800 W... 详细信息

基于激光金属沉积(Laser Metal Deposition,LMD)的再制造利用了增材制造的灵活性,为修复或再制造高价值工程零部件提供了一种极具吸引力和性价比的手段。本工作在航空发动机机匣用铸造铝合金板表面熔覆AlSi10Mg合金,当激光功率P=1800 W、送粉速率f=1.6 g/min、扫描速度v=8 mm/s时,获得了孔隙率仅为0.19%的AlSi10Mg修复层。

关键词：铸造铝合金增材制造送粉速率显微硬度激光金属沉积扫描速度激光功率修复层

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Multi-kernel Correntropy Regression: Robustness, Optimality, and Application on Magnetometer Calibration

arXiv

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arXiv 2023年

作者： Li, Shilei Chen, Yihan Lou, Yunjiang Shi, Dawei Li, Lijing Shi, Ling The Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology Hong Kong The State Key Laboratory of Robotics and System School of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen Shenzhen518055 China The School of Automation Beijing Institute of Technology China The School of Information and Control Engineering China University of Mining and Technology China

This paper investigates the robustness and optimality of the multi-kernel correntropy (MKC) on linear regression. We first derive an upper error bound for a scalar regression problem in the presence of arbitrarily large outliers and state that the kernel bandwidth plays an important role in minimizing the lowest upper error bound. Then, we find that the proposed MKC is related to a specific heavy-tail distribution, where its head shape is consistent with the Gaussian distribution but its tail shape is heavy-tailed, and the extent of heavy-tail is controlled by the kernel bandwidth. It becomes a Gaussian distribution when the bandwidth is infinite, which allows one to tackle both Gaussian and non-Gaussian problems without explicitly investigating the noise distributions. To explore the optimal underlying distribution parameters, an expectation-maximization-like (EM) algorithm is developed to estimate the parameter vectors and the distribution parameters in an alternating manner. The results show that our algorithm can achieve equivalent performance compared with the traditional linear regression under Gaussian noise, and it significantly outperforms the conventional method under heavy-tailed noise. Both numerical simulations and experiments on a magnetometer calibration application verify the effectiveness of the proposed method. Note to Practitioners-The goal of this paper is to enhance the accuracy of conventional linear regression in handling outliers while maintaining its optimality under Gaussian assumptions. Our algorithm is formulated under the maximum likelihood estimation (MLE) framework, assuming the regression residuals follow a type of heavy-tailed noise distribution with an extreme case of Gaussian. The degree of the heavy tail is explored alternatingly using an Expectation-Maximization (EM) algorithm which converges very quickly. The robustness and optimality of the proposed approach are investigated and compared with the traditional approaches. Both th

关键词： Linear regression

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Bacteria Flagella-Mimicking Polymer Multilayer Magnetic Microrobots

SSRN

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SSRN 2024年

作者： Wu, Zhiguang Lu, Liang Bai, Shuang Shi, Jiaqi Zhang, Zhuotao Pan, Yunlu Wang, Wei Wu, Wenfeng Sun, Shoubin Li, Xu Hou, Gang Huang, Tianyun Jia, Yuxin Zuo, Kaiwen Granovsky, Alexander Wu, He Nikolai, Perov School of Medicine and Health Harbin Institute of Technology Harbin China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin China The First Affiliated Hospital of Harbin Medical University Harbin China National Center for Respiratory Medicine State Key Laboratory of Respiratory Health and Multimorbidity National Clinical Research Center for Respiratory Diseases Institute of Respiratory Medicine Chinese Academy of Medical Sciences Department of Pulmonary and Critical Care Medicine Center of Respiratory Medicine China-Japan Friendship Hospital Beijing China College of Science Sichuan Agricultural University Chengdu China The Fourth Affiliated Hospital of Harbin Medical University Harbin China Department of Ophthalmology The Second Hospital Jilin University Changchun China Department of Advanced Manufacturing and Robotics College of Engineering State Key Laboratory for Turbulence and Complex Systems Peking University Beijing China Department of Mathematics Imperial College London United Kingdom Department of Computer Science University of Warwick Coventry United Kingdom Magnetism Department Faculty of Physics Lomonosov Moscow State University Moscow Russia Harbin Medical University China

Learning from natural bacteria flagellum, we demonstrate a magnetic polymer multilayer conical microrobot that bestow the controllable propulsion upon external rotating magnetic field with uniform intensity. The magnetic microrobots were constructed by template-assisted Layer-by-Layer technique technique and subsequent functionalization of magnetic particle onto the big opening of the microrobots. Geometric variables of the polymer microrobots, such as the diameter and wall thickness, can be controlled by selection of porous template and layers of assembly. The microrobots perform controllable propulsion through the manipulation of magnetic field. The comparative analysis of the movement behavior reveals that the deformation of microrobots may attributed to the propulsion upon rotating magnetic field, which is similar as that of natural bacteria. The influence of actuation frequencies and frequencies on the velocity of the microrobots is studied. Such use of polymer polymer multilayer tubular micro/nanoarchitectures results in significant savings in the processing costs and provides a simple and cost-effective fabrication route for the mass production of magnetic polymer microrobots. © 2024, The Authors. All rights reserved.

关键词： Bacteria

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Quantitative Study on the Microstructural Evolution and Dimensional Stability Mechanism of 2024al Alloy During Long-Term Thermal Cycling

SSRN

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SSRN 2023年

作者： Cao, Youfang Jiang, Longtao Shen, Guwei Gong, Deng Rao, Jiancun Chen, Guoqin School of Materials and Engineering Harbin Institute of Technology Harbin150001 China State Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin150001 China Aero Engine Control System Institute Aero Engine Corporation of China Wuxi214063 China AIM Lab Maryland NanoCenter University of Maryland Maryland20742 United States

During the start-stop process of high-precision instruments in service, the critical materials of instruments undergo thermal cycling, resulting in changes in microstructure and dimensions. In this paper, the evolution and coupling effects of dislocations and precipitates within 2024Al alloy during 500 thermal cycles were investigated, and their influence on the dimensional changes was quantitatively characterized and decoupling analyzed. Transmission Electron Microscopy (TEM)/aberration-corrected scanning TEM (CS-TEM), X-ray diffraction (XRD), and Three-Dimensional Atom Probe Tomography (3D-APT) were used for microstructural evolution analysis and quantitative statistics. The dislocation density increased from 3.32×1014 m-2 to 5.75×1014 m-2 after 500 thermal cycles, which accelerated elemental diffusion and provided nucleation sites of precipitates, contributing to an increase in the number density of the S'/S phase from 1.04×1024 m-3 to 1.41×1024 m-3. Based on the quantitative statistics of precipitate types and corresponding volume fractions, the dimensional change induced by precipitate evolution was -1.78×10-4. And the dimensional change caused by the free volume introduced by dislocation density was 3.32×10-6. Comparing these values with the experimental value of -1.94×10-4, it is clear that the precipitate evolution is the main factor that triggers the dimensional changes in the material. © 2023, The Authors. All rights reserved.

关键词： Thermal cycling

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